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Aquino A, Bianchi N, Terrazzan A, Franzese O. Protein Kinase C at the Crossroad of Mutations, Cancer, Targeted Therapy and Immune Response. BIOLOGY 2023; 12:1047. [PMID: 37626933 PMCID: PMC10451643 DOI: 10.3390/biology12081047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/18/2023] [Accepted: 07/21/2023] [Indexed: 08/27/2023]
Abstract
The frequent PKC dysregulations observed in many tumors have made these enzymes natural targets for anticancer applications. Nevertheless, this considerable interest in the development of PKC modulators has not led to the expected therapeutic benefits, likely due to the complex biological activities regulated by PKC isoenzymes, often playing ambiguous and protective functions, further driven by the occurrence of mutations. The structure, regulation and functions of PKCs have been extensively covered in other publications. Herein, we focused on PKC alterations mostly associated with complete functional loss. We also addressed the modest yet encouraging results obtained targeting PKC in selected malignancies and the more frequent negative clinical outcomes. The reported observations advocate the need for more selective molecules and a better understanding of the involved pathways. Furthermore, we underlined the most relevant immune mechanisms controlled by PKC isoforms potentially impacting the immune checkpoint inhibitor blockade-mediated immune recovery. We believe that a comprehensive examination of the molecular features of the tumor microenvironment might improve clinical outcomes by tailoring PKC modulation. This approach can be further supported by the identification of potential response biomarkers, which may indicate patients who may benefit from the manipulation of distinctive PKC isoforms.
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Affiliation(s)
- Angelo Aquino
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy;
| | - Nicoletta Bianchi
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy; (N.B.); (A.T.)
| | - Anna Terrazzan
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy; (N.B.); (A.T.)
- Laboratory for Advanced Therapy Technologies (LTTA), University of Ferrara, 44121 Ferrara, Italy
| | - Ornella Franzese
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy;
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2
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Shete N, Calabrese J, Tonetti DA. Revisiting Estrogen for the Treatment of Endocrine-Resistant Breast Cancer: Novel Therapeutic Approaches. Cancers (Basel) 2023; 15:3647. [PMID: 37509308 PMCID: PMC10377916 DOI: 10.3390/cancers15143647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/10/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
Estrogen receptor (ER)-positive breast cancer is the most common subtype, representing 70-75% of all breast cancers. Several ER-targeted drugs commonly used include the selective estrogen receptor modulator (SERM), tamoxifen (TAM), aromatase inhibitors (AIs) and selective estrogen receptor degraders (SERDs). Through different mechanisms of action, all three drug classes reduce estrogen receptor signaling. Inevitably, resistance occurs, resulting in disease progression. The counterintuitive action of estrogen to inhibit ER-positive breast cancer was first observed over 80 years ago. High-dose estrogen and diethylstilbestrol (DES) were used to treat metastatic breast cancer accompanied by harsh side effects until the approval of TAM in the 1970s. After the development of TAM, randomized trials comparing TAM to estrogen found similar or slightly inferior efficacy but much better tolerability. After decades of research, it was learned that estrogen induces tumor regression only after a period of long-term estrogen deprivation, and the mechanisms of tumor regression were described. Despite the long history of breast cancer treatment with estrogen, this therapeutic modality is now revitalized due to the development of novel estrogenic compounds with improved side effect profiles, newly discovered predictive biomarkers, the development of non-estrogen small molecules and new combination therapeutic approaches.
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Affiliation(s)
- Nivida Shete
- Department of Pharmaceutical Sciences, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Jordan Calabrese
- Department of Pharmaceutical Sciences, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Debra A Tonetti
- Department of Pharmaceutical Sciences, University of Illinois Chicago, Chicago, IL 60612, USA
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Serrano-López EM, Coronado-Parra T, Marín-Vicente C, Szallasi Z, Gómez-Abellán V, López-Andreo MJ, Gragera M, Gómez-Fernández JC, López-Nicolás R, Corbalán-García S. Deciphering the Role and Signaling Pathways of PKCα in Luminal A Breast Cancer Cells. Int J Mol Sci 2022; 23:ijms232214023. [PMID: 36430510 PMCID: PMC9696894 DOI: 10.3390/ijms232214023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/11/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Protein kinase C (PKC) comprises a family of highly related serine/threonine protein kinases involved in multiple signaling pathways, which control cell proliferation, survival, and differentiation. The role of PKCα in cancer has been studied for many years. However, it has been impossible to establish whether PKCα acts as an oncogene or a tumor suppressor. Here, we analyzed the importance of PKCα in cellular processes such as proliferation, migration, or apoptosis by inhibiting its gene expression in a luminal A breast cancer cell line (MCF-7). Differential expression analysis and phospho-kinase arrays of PKCα-KD vs. PKCα-WT MCF-7 cells identified an essential set of proteins and oncogenic kinases of the JAK/STAT and PI3K/AKT pathways that were down-regulated, whereas IGF1R, ERK1/2, and p53 were up-regulated. In addition, unexpected genes related to the interferon pathway appeared down-regulated, while PLC, ERBB4, or PDGFA displayed up-regulated. The integration of this information clearly showed us the usefulness of inhibiting a multifunctional kinase-like PKCα in the first step to control the tumor phenotype. Then allowing us to design a possible selection of specific inhibitors for the unexpected up-regulated pathways to further provide a second step of treatment to inhibit the proliferation and migration of MCF-7 cells. The results of this study suggest that PKCα plays an oncogenic role in this type of breast cancer model. In addition, it reveals the signaling mode of PKCα at both gene expression and kinase activation. In this way, a wide range of proteins can implement a new strategy to fine-tune the control of crucial functions in these cells and pave the way for designing targeted cancer therapies.
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Affiliation(s)
- Emilio M. Serrano-López
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, El Palmar, 30120 Murcia, Spain
| | - Teresa Coronado-Parra
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Microscopy Core Unit, Área Científica y Técnica de Investigación, Universidad de Murcia, 30100 Murcia, Spain
| | - Consuelo Marín-Vicente
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Cardiovascular Proteomics and Developmental Biology Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
| | - Zoltan Szallasi
- Computational Health Informatics Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Department of Bioinformatics, Semmelweis University, H-1092 Budapest, Hungary
| | - Victoria Gómez-Abellán
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Department of Cellular Biology and Histology, Biology School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
| | - María José López-Andreo
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Molecular Biology Unit, Área Científica y Técnica de Investigación, Universidad de Murcia, 30100 Murcia, Spain
| | - Marcos Gragera
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Centro Nacional Biotecnología, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain
| | - Juan C. Gómez-Fernández
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, El Palmar, 30120 Murcia, Spain
| | - Rubén López-Nicolás
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, El Palmar, 30120 Murcia, Spain
- Department of Bromatology and Nutrition, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Correspondence: (R.L.-N.); (S.C.-G.)
| | - Senena Corbalán-García
- Department of Biochemistry and Molecular Biology A, Veterinary School, Universidad de Murcia, CEIR Campus Mare Nostrum (CMN), 30100 Murcia, Spain
- Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, El Palmar, 30120 Murcia, Spain
- Correspondence: (R.L.-N.); (S.C.-G.)
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Black AR, Black JD. The complexities of PKCα signaling in cancer. Adv Biol Regul 2021; 80:100769. [PMID: 33307285 PMCID: PMC8141086 DOI: 10.1016/j.jbior.2020.100769] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 11/15/2020] [Indexed: 01/06/2023]
Abstract
Protein kinase C α (PKCα) is a ubiquitously expressed member of the PKC family of serine/threonine kinases with diverse functions in normal and neoplastic cells. Early studies identified anti-proliferative and differentiation-inducing functions for PKCα in some normal tissues (e.g., regenerating epithelia) and pro-proliferative effects in others (e.g., cells of the hematopoietic system, smooth muscle cells). Additional well documented roles of PKCα signaling in normal cells include regulation of the cytoskeleton, cell adhesion, and cell migration, and PKCα can function as a survival factor in many contexts. While a majority of tumors lose expression of PKCα, others display aberrant overexpression of the enzyme. Cancer-related mutations in PKCα are uncommon, but rare examples of driver mutations have been detected in certain cancer types (e. g., choroid gliomas). Here we review the role of PKCα in various cancers, describe mechanisms by which PKCα affects cancer-related cell functions, and discuss how the diverse functions of PKCα contribute to tumor suppressive and tumor promoting activities of the enzyme. We end the discussion by addressing mutations and expression of PKCα in tumors and the clinical relevance of these findings.
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Affiliation(s)
- Adrian R Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Jennifer D Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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Protein Kinase C Alpha (PKCα) overexpression leads to a better response to retinoid acid therapy through Retinoic Acid Receptor Beta (RARβ) activation in mammary cancer cells. J Cancer Res Clin Oncol 2020; 146:3241-3253. [PMID: 32865619 DOI: 10.1007/s00432-020-03368-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 08/18/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE Retinoids have proved to be effective for hematologic malignancies treatment but till nowadays, their use as single agent for the solid tumor's management is still controversial. All-trans retinoic acid (ATRA), the main active metabolite of vitamin A, exerts non-genomic interactions with different members of the protein kinase C (PKC) family, recognized modulators of different tumor progression pathways. To determine whether a group of patients could become benefited employing a retinoid therapy, in this study we have evaluated whether PKCα expression (a poor prognosis marker in breast cancer) could sensitizes mammary cells to ATRA treatment. METHODS PKCα overexpression was achieved by stable transfection and confirmed by western blot. Transfected PKC functionality was determined by nuclear translocation-induction and confocal microscopy. In vitro proliferation was evaluated by cell counting and cell cycle distribution was analyzed by flow cytometry. In vivo studies were performed to evaluate orthotopic tumor growth and experimental lung colonization. Retinoic acid response elements (RARE) and AP1 sites-dependent activity was studied by gene reporter assays and retinoic acid receptors (RARs) were measured by RT-qPCR. RESULTS Our findings suggest that high PKCα levels improve the differentiation response to ATRA in a RAR signaling-dependent manner. Moreover, RARβ expression appears to be critical to induce ATRA sensitization, throughout AP1 trans-repression. CONCLUSION Here we propose that retinoids could lead a highly personalized anticancer treatment, bringing benefits to patients with aggressive breast tumors resulting from high PKCα expression but, an adequate expression of the RARβ receptor is required to ensure the effect on this process.
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Hermyt E, Zmarzły N, Grabarek B, Kruszniewska-Rajs C, Gola J, Jęda-Golonka A, Szczepanek K, Mazurek U, Witek A. Interplay between miRNAs and Genes Associated with Cell Proliferation in Endometrial Cancer. Int J Mol Sci 2019; 20:ijms20236011. [PMID: 31795319 PMCID: PMC6928856 DOI: 10.3390/ijms20236011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/20/2019] [Accepted: 11/27/2019] [Indexed: 12/11/2022] Open
Abstract
Endometrial cancer develops as a result of abnormal cell growth associated with uncontrolled cell proliferation, excessive activation of signaling pathways and miRNA activity. The aim of this study was to determine the expression profile of genes associated with cell proliferation and to assess which miRNAs can participate in the regulation of their expression. The study enrolled 40 patients with endometrial cancer and 10 patients without neoplastic changes. The expression profile of genes associated with cell proliferation and the expression profile of miRNAs were assessed using microarrays. RT-qPCR was performed to validate mRNA microarray results. The mirTAR tool was used to identify miRNAs that regulate the activity of genes associated with cell proliferation. Decreased expression of IGF1 and MYLK, as well as SOD2 overexpression, were observed in endometrial cancer using both mRNA microarrays and RT-qPCR. Microarray analysis showed low levels of NES and PRKCA, but this was only partially validated using RT-qPCR. Reduced activity of MYLK may be caused by increased miR-200c, miR-155 and miR-200b expression. Cell proliferation is disturbed in endometrial cancer, which may be associated with an overexpression of miR-200a, miR-200c, and miR-155, making it a potential diagnostic marker.
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Affiliation(s)
- Ewelina Hermyt
- Department of Gynecology and Obstetrics, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Medyków 14, 40-752 Katowice, Poland; (E.H.); (A.J.-G.); (K.S.); (A.W.)
| | - Nikola Zmarzły
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Jedności 8, 41-200 Sosnowiec, Poland; (B.G.); (C.K.-R.); (J.G.)
- Department of Histology, Faculty of Medicine, University of Technology, Park Hutniczy 3-5, 41-800 Zabrze, Poland
- Correspondence:
| | - Beniamin Grabarek
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Jedności 8, 41-200 Sosnowiec, Poland; (B.G.); (C.K.-R.); (J.G.)
- Department of Histology, Faculty of Medicine, University of Technology, Park Hutniczy 3-5, 41-800 Zabrze, Poland
- Center of Oncology, M. Sklodowska-Curie Memorial Institute, Cracow Branch, Garncarska 11, 31-115 Kraków, Poland
| | - Celina Kruszniewska-Rajs
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Jedności 8, 41-200 Sosnowiec, Poland; (B.G.); (C.K.-R.); (J.G.)
| | - Joanna Gola
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Jedności 8, 41-200 Sosnowiec, Poland; (B.G.); (C.K.-R.); (J.G.)
| | - Agnieszka Jęda-Golonka
- Department of Gynecology and Obstetrics, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Medyków 14, 40-752 Katowice, Poland; (E.H.); (A.J.-G.); (K.S.); (A.W.)
| | - Katarzyna Szczepanek
- Department of Gynecology and Obstetrics, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Medyków 14, 40-752 Katowice, Poland; (E.H.); (A.J.-G.); (K.S.); (A.W.)
| | - Urszula Mazurek
- Jozef Tyszkiewicz Higher School in Bielsko-Biała, Nadbrzeżna 12, 43-300 Bielsko-Biała, Poland;
| | - Andrzej Witek
- Department of Gynecology and Obstetrics, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Medyków 14, 40-752 Katowice, Poland; (E.H.); (A.J.-G.); (K.S.); (A.W.)
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Jeong SB, Im JH, Yoon JH, Bui QT, Lim SC, Song JM, Shim Y, Yun J, Hong J, Kang KW. Essential Role of Polo-like Kinase 1 (Plk1) Oncogene in Tumor Growth and Metastasis of Tamoxifen-Resistant Breast Cancer. Mol Cancer Ther 2018; 17:825-837. [PMID: 29437878 DOI: 10.1158/1535-7163.mct-17-0545] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 10/17/2017] [Accepted: 02/01/2018] [Indexed: 02/07/2023]
Abstract
The most common therapy for estrogen receptor-positive breast cancer is antihormone therapy, such as tamoxifen. However, acquisition of resistance to tamoxifen in one third of patients presents a serious clinical problem. Polo-like kinase 1 (Plk1) is a key oncogenic regulator of completion of G2-M phase of the cell cycle. We assessed Plk1 expression in five chemoresistant cancer cell types and found that Plk1 and its downstream phosphatase Cdc25c were selectively overexpressed in tamoxifen-resistant MCF-7 (TAMR-MCF-7) breast cancer cells. Real-time monitoring of cell proliferation also showed that TAMR-MCF-7 cells were more sensitive to inhibition of cell proliferation by the ATP-competitive Plk1 inhibitor BI2536 than were the parent MCF-7 cells. Moreover, BI2536 suppressed expression of epithelial-mesenchymal transition marker proteins and 3D spheroid formation in TAMR-MCF-7 cells. Using TAMR-MCF-7 cell-implanted xenograft and spleen-liver metastasis models, we showed that BI2536 inhibited tumor growth and metastasis in vivo Our results suggest that Plk1 could be a novel target for the treatment of tamoxifen-resistant breast cancer. Mol Cancer Ther; 17(4); 825-37. ©2018 AACR.
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Affiliation(s)
- Sung Baek Jeong
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Ji Hye Im
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Jeong-Hoon Yoon
- Department of Oral & Maxillofacial Pathology, College of Dentistry, Daejeon Dental Hospital, Wonkwang University, Daejeon, South Korea
| | - Quyen Thu Bui
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Sung Chul Lim
- Department of Pathology, College of Medicine, Chosun University, Gwangju, South Korea
| | - Joon Myong Song
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Yumi Shim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Jieun Yun
- Department of Pharmaceutical Engineering, College of Science & Engineering, Cheongju University, Cheongju, South Korea
| | - Janghee Hong
- Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Keon Wook Kang
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea.
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8
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Protein kinase C α enhances migration of breast cancer cells through FOXC2-mediated repression of p120-catenin. BMC Cancer 2017; 17:832. [PMID: 29216867 PMCID: PMC5719564 DOI: 10.1186/s12885-017-3827-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 11/23/2017] [Indexed: 11/30/2022] Open
Abstract
Background Despite recent advances in the diagnosis and treatment of breast cancer, metastasis remains the main cause of death. Since migration of tumor cells is considered a prerequisite for tumor cell invasion and metastasis, a pressing goal in tumor biology has been to elucidate factors regulating their migratory activity. Protein kinase C alpha (PKCα) is a serine-threonine protein kinase implicated in cancer metastasis and associated with poor prognosis in breast cancer patients. In this study, we set out to define the signaling axis mediated by PKCα to promote breast cancer cell migration. Methods Oncomine™ overexpression analysis was used to probe for PRKCA (PKCα) and FOXC2 expression in mRNA datasets. The heat map of PRKCA, FOXC2, and CTNND1 were obtained from the UC Santa Cruz platform. Survival data were obtained by PROGgene and available at http://www.compbio.iupui.edu/proggene. Markers for EMT and adherens junction were assessed by Western blotting and quantitative polymerase chain reaction. Effects of PKCα and FOXC2 on migration and invasion were assessed in vitro by transwell migration and invasion assays respectively. Cellular localization of E-cadherin and p120-catenin was determined by immunofluorescent staining. Promoter activity of p120-catenin was determined by dual luciferase assay using a previously validated p120-catenin reporter construct. Interaction between FOXC2 and p120-catenin promoter was verified by chromatin immunoprecipitation assay. Results We determined that PKCα expression is necessary to maintain the migratory and invasive phenotype of both endocrine resistant and triple negative breast cancer cell lines. FOXC2 acts as a transcriptional repressor downstream of PKCα, and represses p120-catenin expression. Consequently, loss of p120-catenin leads to destabilization of E-cadherin at the adherens junction. Inhibition of either PKCα or FOXC2 is sufficient to rescue p120-catenin expression and trigger relocalization of p120-catenin and E-cadherin to the cell membrane, resulting in reduced tumor cell migration and invasion. Conclusions Taken together, these results suggest that breast cancer metastasis may partially be controlled through PKCα/FOXC2-dependent repression of p120-catenin and highlight the potential for PKCα signal transduction networks to be targeted for the treatment of endocrine resistant and triple negative breast cancer. Electronic supplementary material The online version of this article (10.1186/s12885-017-3827-y) contains supplementary material, which is available to authorized users.
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Protein kinase C inhibitor chelerythrine selectively inhibits proliferation of triple-negative breast cancer cells. Sci Rep 2017; 7:2022. [PMID: 28515445 PMCID: PMC5435721 DOI: 10.1038/s41598-017-02222-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 04/07/2017] [Indexed: 12/25/2022] Open
Abstract
Triple-negative breast cancer (TNBC) is a subtype of breast cancer lacking targeted therapy currently. Recent studies imply that protein kinase C may play important roles in TNBC development and could be a specific target. In this study, we evaluated the anti-proliferative activity of PKC inhibitor chelerythrine on a panel of breast cancer cell lines. Chelerythrine selectively inhibited the growth of TNBC cell lines compared to non-TNBC cell lines as demonstrated by in vitro cell proliferation assay and colony formation assay, as well as evidenced by in vivo xenograft assay. The selective anti-proliferative effect of chelerythrine was associated with induction of apoptosis in TNBC cell lines. We further demonstrated that PKN2, one of the PKC subtypes, was highly expressed in TNBC cell lines, and knocking down PKN2 in TNBC cells inhibited colony formation and xenograft growth. This indicates that PKN2 is required for the survival of TNBC cells, and could be the target mediates the selective activity of chelerythrine. Finally, combination of chelerythrine and chemotherapy reagent taxol showed synergistic/additive effect on TNBC cell lines. Our results suggest chelerythrine or other PKC inhibitors may be promising regimens for TNBC tumors.
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10
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Liu J, Zheng S, Akerstrom VL, Yuan C, Ma Y, Zhong Q, Zhang C, Zhang Q, Guo S, Ma P, Skripnikova EV, Bratton MR, Pannuti A, Miele L, Wiese TE, Wang G. Fulvestrant-3 Boronic Acid (ZB716): An Orally Bioavailable Selective Estrogen Receptor Downregulator (SERD). J Med Chem 2016; 59:8134-40. [PMID: 27529700 DOI: 10.1021/acs.jmedchem.6b00753] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Orally bioavailable SERDs may offer greater systemic drug exposure, improved clinical efficacy, and more durable treatment outcome for patients with ER-positive endocrine-resistant breast cancer. We report the design and synthesis of a boronic acid modified fulvestrant (5, ZB716), which binds to ERα competitively (IC50 = 4.1 nM) and effectively downregulates ERα in both tamoxifen-sensitive and tamoxifen-resistant breast cancer cells. Furthermore, It has superior oral bioavailability (AUC = 2547.1 ng·h/mL) in mice, indicating its promising clinical utility as an oral SERD.
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Affiliation(s)
- Jiawang Liu
- RCMI Cancer Research Center, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Shilong Zheng
- RCMI Cancer Research Center, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Victoria L Akerstrom
- Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center , New Orleans, Louisiana 70112, United States
| | - Chester Yuan
- Xiamen Medichance Laboratory , Xiamen 361022, China
| | - Youning Ma
- Xiamen Medichance Laboratory , Xiamen 361022, China
| | - Qiu Zhong
- RCMI Cancer Research Center, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Changde Zhang
- RCMI Cancer Research Center, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Qiang Zhang
- RCMI Cancer Research Center, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Shanchun Guo
- RCMI Cancer Research Center, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Peng Ma
- College of Pharmacy, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Elena V Skripnikova
- College of Pharmacy, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Melyssa R Bratton
- College of Pharmacy, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Antonio Pannuti
- Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center , New Orleans, Louisiana 70112, United States
| | - Lucio Miele
- Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center , New Orleans, Louisiana 70112, United States
| | - Thomas E Wiese
- College of Pharmacy, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
| | - Guangdi Wang
- RCMI Cancer Research Center, Xavier University of Louisiana , New Orleans, Louisiana 70125, United States
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Xiong R, Patel HK, Gutgesell LM, Zhao J, Delgado-Rivera L, Pham TND, Zhao H, Carlson K, Martin T, Katzenellenbogen JA, Moore TW, Tonetti DA, Thatcher GRJ. Selective Human Estrogen Receptor Partial Agonists (ShERPAs) for Tamoxifen-Resistant Breast Cancer. J Med Chem 2015; 59:219-237. [PMID: 26681208 DOI: 10.1021/acs.jmedchem.5b01276] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Almost 70% of breast cancers are estrogen receptor α (ERα) positive. Tamoxifen, a selective estrogen receptor modulator (SERM), represents the standard of care for many patients; however, 30-50% develop resistance, underlining the need for alternative therapeutics. Paradoxically, agonists at ERα such as estradiol (E2) have demonstrated clinical efficacy in patients with heavily treated breast cancer, although side effects in gynecological tissues are unacceptable. A drug that selectively mimics the actions of E2 in breast cancer therapy but minimizes estrogenic effects in other tissues is a novel, therapeutic alternative. We hypothesized that a selective human estrogen receptor partial agonist (ShERPA) at ERα would provide such an agent. Novel benzothiophene derivatives with nanomolar potency in breast cancer cell cultures were designed. Several showed partial agonist activity, with potency of 0.8-76 nM, mimicking E2 in inhibiting growth of tamoxifen-resistant breast cancer cell lines. Three ShERPAs were tested and validated in xenograft models of endocrine-independent and tamoxifen-resistant breast cancer, and in contrast to E2, ShERPAs did not cause significant uterine growth.
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Affiliation(s)
- Rui Xiong
- Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
| | - Hitisha K Patel
- Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
| | - Lauren M Gutgesell
- Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
| | - Jiong Zhao
- Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
| | - Loruhama Delgado-Rivera
- Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
| | - Thao N D Pham
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
| | - Huiping Zhao
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
| | - Kathryn Carlson
- Department of Chemistry, University of Illinois, Urbana Champaign, 600 South Mathews Avenue, Urbana, IL 61801
| | - Teresa Martin
- Department of Chemistry, University of Illinois, Urbana Champaign, 600 South Mathews Avenue, Urbana, IL 61801
| | - John A Katzenellenbogen
- Department of Chemistry, University of Illinois, Urbana Champaign, 600 South Mathews Avenue, Urbana, IL 61801
| | - Terry W Moore
- Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
| | - Debra A Tonetti
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
| | - Gregory R J Thatcher
- Department of Medicinal Chemistry & Pharmacognosy, University of Illinois at Chicago, 833 S Wood St, Chicago, Illinois 60612
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12
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Bentin Toaldo C, Alexi X, Beelen K, Kok M, Hauptmann M, Jansen M, Berns E, Neefjes J, Linn S, Michalides R, Zwart W. Protein Kinase A-induced tamoxifen resistance is mediated by anchoring protein AKAP13. BMC Cancer 2015; 15:588. [PMID: 26272591 PMCID: PMC4536754 DOI: 10.1186/s12885-015-1591-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 08/03/2015] [Indexed: 11/16/2022] Open
Abstract
Background Estrogen Receptor alpha (ERα)-positive breast cancer patients receive endocrine therapy, often in the form of tamoxifen. However, resistance to tamoxifen is frequently observed. A signalling cascade that leads to tamoxifen resistance is dictated by activation of the Protein Kinase A (PKA) pathway, which leads to phosphorylation of ERα on Serine 305 and receptor activation, following tamoxifen binding. Thus far, it remains elusive what protein complexes enable the PKA-ERα interaction resulting in ERα Serine 305 phosphorylation. Methods We performed immunohistochemistry to detect ERαSerine 305 phosphorylation in a cohort of breast cancer patients who received tamoxifen treatment in the metastatic setting. From the same tumor specimens, Agilent 44 K gene expression analyses were performed and integrated with clinicopathological data and survival information. In vitro analyses were performed using MCF7 breast cancer cells, which included immunoprecipitations and Fluorescence Resonance Energy Transfer (FRET) analyses to illustrate ERα complex formation. siRNA mediated knockdown experiments were performed to assess effects on ERαSerine 305 phosphorylation status, ERα/PKA interactions and downstream responsive gene activity. Results Stratifying breast tumors on ERα Serine 305 phosphorylation status resulted in the identification of a gene network centered upon AKAP13. AKAP13 mRNA expression levels correlate with poor outcome in patients who received tamoxifen treatment in the metastatic setting. In addition, AKAP13 mRNA levels correlate with ERαSerine 305 phosphorylation in breast tumor samples, suggesting a functional connection between these two events. In a luminal breast cancer cell line, AKAP13 was found to interact with ERα as well as with a regulatory subunit of PKA. Knocking down of AKAP13 prevented PKA-mediated Serine 305 phosphorylation of ERα and abrogated PKA-driven tamoxifen resistance, illustrating that AKAP13 is an essential protein in this process. Conclusions We show that the PKA-anchoring protein AKAP13 is essential for the phosphorylation of ERαS305, which leads to tamoxifen resistance both in cell lines and tamoxifen-treated breast cancer patients. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1591-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cristiane Bentin Toaldo
- Division of Molecular Pathology, the Netherlands Cancer Institute, Amsterdam, The Netherlands.
| | - Xanthippi Alexi
- Division of Molecular Pathology, the Netherlands Cancer Institute, Amsterdam, The Netherlands.
| | - Karin Beelen
- Division of Molecular Pathology, the Netherlands Cancer Institute, Amsterdam, The Netherlands.
| | - Marleen Kok
- Division of Molecular Pathology, the Netherlands Cancer Institute, Amsterdam, The Netherlands.
| | - Michael Hauptmann
- Division of Psychosocial Research and Epidemiology, the Netherlands Cancer Institute, Amsterdam, The Netherlands.
| | - Maurice Jansen
- Department of Medical Oncology, Josephine Nefkens Institute and Cancer Genomics Center, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands.
| | - Els Berns
- Department of Medical Oncology, Josephine Nefkens Institute and Cancer Genomics Center, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands.
| | - Jacques Neefjes
- Division of Cell Biology, the Netherlands Cancer Institute, Amsterdam, The Netherlands.
| | - Sabine Linn
- Division of Molecular Pathology, the Netherlands Cancer Institute, Amsterdam, The Netherlands. .,Department of Medical Oncology, the Netherlands Cancer Institute, Amsterdam, The Netherlands.
| | - Rob Michalides
- Division of Cell Biology, the Netherlands Cancer Institute, Amsterdam, The Netherlands.
| | - Wilbert Zwart
- Division of Molecular Pathology, the Netherlands Cancer Institute, Amsterdam, The Netherlands.
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13
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Abera MB, Kazanietz MG. Protein kinase Cα mediates erlotinib resistance in lung cancer cells. Mol Pharmacol 2015; 87:832-41. [PMID: 25724832 DOI: 10.1124/mol.115.097725] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Overexpression and mutational activation of the epidermal growth factor receptor (EGFR) plays an important role in the pathogenesis of non-small cell lung cancer (NSCLC). EGFR tyrosine-kinase inhibitors (TKIs) are given as a primary therapy for advanced patients with EGFR-activating mutations; however, the majority of these tumors relapse and patients eventually develop resistance to TKIs. To address a potential role of protein kinase C (PKC) isozymes in the resistance to TKIs, we used the isogenic NSCLC H1650 cell line and its erlotinib-resistant derivative H1650-M3, a cell line that displays a mesenchymal-like morphology driven by transforming growth factor-β signaling. We found that H1650-M3 cells display remarkable PKCα upregulation and PKCδ downregulation. Notably, silencing PKCα from H1650-M3 cells using RNA interference caused a significant reduction in the expression of epithelial-to-mesenchymal transition (EMT) markers vimentin, Zeb2, Snail, and Twist. Moreover, pharmacological inhibition or PKCα RNA interference depletion and PKCδ restoring sensitized H1650-M3 cells to erlotinib. Whereas ectopic overexpression of PKCα in parental H1650 cells was not sufficient to alter the expression of EMT genes or to confer resistance to erlotinib, it caused downregulation of PKCδ expression, suggesting a unidirectional crosstalk. Finally, mechanistic studies revealed that PKCα upregulation in H1650-M3 cells is driven by transforming growth factor-β. Our results identified important roles for specific PKC isozymes in erlotinib resistance and EMT in lung cancer cells, and highlight PKCα as a potential target for lung cancer treatment.
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Affiliation(s)
- Mahlet B Abera
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Marcelo G Kazanietz
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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14
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Abstract
The successful use of high-dose synthetic estrogens to treat postmenopausal metastatic breast cancer is the first effective 'chemical therapy' proven in clinical trial to treat any cancer. This review documents the clinical use of estrogen for breast cancer treatment or estrogen replacement therapy (ERT) in postmenopausal hysterectomized women, which can either result in breast cancer cell growth or breast cancer regression. This has remained a paradox since the 1950s until the discovery of the new biology of estrogen-induced apoptosis at the end of the 20th century. The key to triggering apoptosis with estrogen is the selection of breast cancer cell populations that are resistant to long-term estrogen deprivation. However, estrogen-independent growth occurs through trial and error. At the cellular level, estrogen-induced apoptosis is dependent upon the presence of the estrogen receptor (ER), which can be blocked by nonsteroidal or steroidal antiestrogens. The shape of an estrogenic ligand programs the conformation of the ER complex, which, in turn, can modulate estrogen-induced apoptosis: class I planar estrogens (e.g., estradiol) trigger apoptosis after 24 h, whereas class II angular estrogens (e.g., bisphenol triphenylethylene) delay the process until after 72 h. This contrasts with paclitaxel, which causes G2 blockade with immediate apoptosis. The process is complete within 24 h. Estrogen-induced apoptosis is modulated by glucocorticoids and cSrc inhibitors, but the target mechanism for estrogen action is genomic and not through a nongenomic pathway. The process is stepwise through the creation of endoplasmic reticulum stress and inflammatory responses, which then initiate an unfolded protein response. This, in turn, initiates apoptosis through the intrinsic pathway (mitochondrial) with the subsequent recruitment of the extrinsic pathway (death receptor) to complete the process. The symmetry of the clinical and laboratory studies now permits the creation of rules for the future clinical application of ERT or phytoestrogen supplements: a 5-year gap is necessary after menopause to permit the selection of estrogen-deprived breast cancer cell populations to cause them to become vulnerable to apoptotic cell death. Earlier treatment with estrogen around menopause encourages growth of ER-positive tumor cells, as the cells are still dependent on estrogen to maintain replication within the expanding population. An awareness of the evidence that the molecular events associated with estrogen-induced apoptosis can be orchestrated in the laboratory in estrogen-deprived breast cancers now supports the clinical findings regarding the treatment of metastatic breast cancer following estrogen deprivation, decreases in mortality following long-term antihormonal adjuvant therapy, and the results of treatment with ERT and ERT plus progestin in the Women's Health Initiative for women over the age of 60. Principles have emerged for understanding and applying physiological estrogen therapy appropriately by targeting the correct patient populations.
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Affiliation(s)
- V Craig Jordan
- Departments of Breast Medical Oncology and Molecular and Cellular OncologyMD Anderson Cancer Center, Houston, Texas 77030, USA
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15
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Garg R, Benedetti LG, Abera MB, Wang H, Abba M, Kazanietz MG. Protein kinase C and cancer: what we know and what we do not. Oncogene 2014; 33:5225-37. [PMID: 24336328 DOI: 10.1038/onc.2013.524] [Citation(s) in RCA: 197] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/20/2013] [Accepted: 10/20/2013] [Indexed: 02/08/2023]
Abstract
Since their discovery in the late 1970s, protein kinase C (PKC) isozymes represent one of the most extensively studied signaling kinases. PKCs signal through multiple pathways and control the expression of genes relevant for cell cycle progression, tumorigenesis and metastatic dissemination. Despite the vast amount of information concerning the mechanisms that control PKC activation and function in cellular models, the relevance of individual PKC isozymes in the progression of human cancer is still a matter of controversy. Although the expression of PKC isozymes is altered in multiple cancer types, the causal relationship between such changes and the initiation and progression of the disease remains poorly defined. Animal models developed in the last years helped to better understand the involvement of individual PKCs in various cancer types and in the context of specific oncogenic alterations. Unraveling the enormous complexity in the mechanisms by which PKC isozymes have an impact on tumorigenesis and metastasis is key for reassessing their potential as pharmacological targets for cancer treatment.
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Affiliation(s)
- R Garg
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - L G Benedetti
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - M B Abera
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - H Wang
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - M Abba
- Centro de Investigaciones Inmunológicas Básicas y Aplicadas (CINIBA), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - M G Kazanietz
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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16
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Molloy ME, White BEP, Gherezghiher T, Michalsen BT, Xiong R, Patel H, Zhao H, Maximov PY, Jordan VC, Thatcher GRJ, Tonetti DA. Novel selective estrogen mimics for the treatment of tamoxifen-resistant breast cancer. Mol Cancer Ther 2014; 13:2515-26. [PMID: 25205655 DOI: 10.1158/1535-7163.mct-14-0319] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Endocrine-resistant breast cancer is a major clinical obstacle. The use of 17β-estradiol (E2) has reemerged as a potential treatment option following exhaustive use of tamoxifen or aromatase inhibitors, although side effects have hindered its clinical usage. Protein kinase C alpha (PKCα) expression was shown to be a predictor of disease outcome for patients receiving endocrine therapy and may predict a positive response to an estrogenic treatment. Here, we have investigated the use of novel benzothiophene selective estrogen mimics (SEM) as an alternative to E2 for the treatment of tamoxifen-resistant breast cancer. Following in vitro characterization of SEMs, a panel of clinically relevant PKCα-expressing, tamoxifen-resistant models were used to investigate the antitumor effects of these compounds. SEM treatment resulted in growth inhibition and apoptosis of tamoxifen-resistant cell lines in vitro. In vivo SEM treatment induced tumor regression of tamoxifen-resistant T47D:A18/PKCα and T47D:A18-TAM1 tumor models. T47D:A18/PKCα tumor regression was accompanied by translocation of estrogen receptor (ER) α to extranuclear sites, possibly defining a mechanism through which these SEMs initiate tumor regression. SEM treatment did not stimulate growth of E2-dependent T47D:A18/neo tumors. In addition, unlike E2 or tamoxifen, treatment with SEMs did not stimulate uterine weight gain. These findings suggest the further development of SEMs as a feasible therapeutic strategy for the treatment of endocrine-resistant breast cancer without the side effects associated with E2.
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Affiliation(s)
- Mary Ellen Molloy
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Bethany E Perez White
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Teshome Gherezghiher
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Bradley T Michalsen
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Rui Xiong
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Hitisha Patel
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Huiping Zhao
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Philipp Y Maximov
- Department of Oncology, Georgetown University, Lombardi Comprehensive Cancer Center, Washington, District of Columbia
| | - V Craig Jordan
- Department of Oncology, Georgetown University, Lombardi Comprehensive Cancer Center, Washington, District of Columbia
| | - Gregory R J Thatcher
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Debra A Tonetti
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois.
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17
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Ribeiro JR, Freiman RN. Estrogen signaling crosstalk: Implications for endocrine resistance in ovarian cancer. J Steroid Biochem Mol Biol 2014; 143:160-73. [PMID: 24565562 PMCID: PMC4127339 DOI: 10.1016/j.jsbmb.2014.02.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 02/04/2014] [Accepted: 02/13/2014] [Indexed: 12/14/2022]
Abstract
Resistance to anti-estrogen therapies is a prominent challenge in the treatment of ovarian cancer. Tumors develop endocrine resistance by acquiring adaptations that help them rely on alternative oncogenic signaling cascades, which crosstalk with estrogen signaling pathways. An understanding of estrogen signaling crosstalk with these growth promoting cascades is essential in order to maximize efficacy of anti-estrogen treatments in ovarian cancer. Herein, we provide an overview of estrogen signaling in ovarian cancer and discuss the major challenges associated with anti-estrogen therapies. We also review what is currently known about how genomic and non-genomic estrogen signaling pathways crosstalk with several major oncogenic signaling cascades. The insights provided here illustrate existing strategies for targeting endocrine resistant ovarian tumors and may help identify new strategies to improve the treatment of this disease.
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Affiliation(s)
- Jennifer R Ribeiro
- Brown University, Pathobiology Graduate Program, 70 Ship St., Providence, RI 02903, USA.
| | - Richard N Freiman
- Brown University, Pathobiology Graduate Program, 70 Ship St., Providence, RI 02903, USA; Brown University, Department of Molecular and Cellular Biology and Biochemistry, 70 Ship St., Providence, RI 02903, USA.
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18
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Phuong NTT, Lim SC, Kim YM, Kang KW. Aromatase induction in tamoxifen-resistant breast cancer: Role of phosphoinositide 3-kinase-dependent CREB activation. Cancer Lett 2014; 351:91-9. [PMID: 24836190 DOI: 10.1016/j.canlet.2014.05.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 04/28/2014] [Accepted: 05/01/2014] [Indexed: 02/07/2023]
Abstract
Estrogens are important for the development and growth of estrogen receptor (ER)-positive breast cancer, for which anti-estrogen therapy is one of the most effective treatments. However, its efficacy can be limited by either de novo or acquired resistance. Aromatase is a key enzyme for the biosynthesis of estrogens, and inhibition of this enzyme leads to profound hypoestrogenism. Here, we found that the basal expression and activity of aromatase were significantly increased in tamoxifen (TAM)-resistant human breast cancer (TAMR-MCF-7) cells compared to control MCF-7 cells. We further revealed that aromatase immunoreactivity in tumor tissues was increased in recurrence group after TAM therapy compared to non-recurrence group after TAM therapy. Phosphorylation of Akt, extracellular signal-regulated kinase (ERK), and p38 kinase were all increased in TAMR-MCF-7 cells. Inhibition of phosphoinositide 3-kinase (PI3K) suppressed the transactivation of the aromatase gene and its enzyme activity. Furthermore, we have also shown that PI3K/Akt-dependent cAMP-response element binding protein (CREB) activation was required for the enhanced expression of aromatase in TAMR-MCF-7 cells. Our findings suggest that aromatase expression is up-regulated in TAM-resistant breast cancer via PI3K/Akt-dependent CREB activation.
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Affiliation(s)
- Nguyen Thi Thuy Phuong
- College of Pharmacy, Chosun University, Gwangju 501-759, Republic of Korea; College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Sung Chul Lim
- Department of Pathology, College of Medicine, Chosun University, Gwangju 501-759, Republic of Korea
| | - Young Mi Kim
- College of Pharmacy, Hanyang University, Republic of Korea
| | - Keon Wook Kang
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
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19
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Hsu YH, Yao J, Chan LC, Wu TJ, Hsu JL, Fang YF, Wei Y, Wu Y, Huang WC, Liu CL, Chang YC, Wang MY, Li CW, Shen J, Chen MK, Sahin AA, Sood A, Mills GB, Yu D, Hortobagyi GN, Hung MC. Definition of PKC-α, CDK6, and MET as therapeutic targets in triple-negative breast cancer. Cancer Res 2014; 74:4822-35. [PMID: 24970481 DOI: 10.1158/0008-5472.can-14-0584] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Triple-negative breast cancer (TNBC) is a highly heterogeneous and recurrent subtype of breast cancer that lacks an effective targeted therapy. To identify candidate therapeutic targets, we profiled global gene expression in TNBC and breast tumor-initiating cells with a patient survival dataset. Eight TNBC-related kinases were found to be overexpressed in TNBC cells with stem-like properties. Among them, expression of PKC-α, MET, and CDK6 correlated with poorer survival outcomes. In cases coexpressing two of these three kinases, survival rates were lower than in cases where only one of these kinases was expressed. In functional tests, two-drug combinations targeting these three kinases inhibited TNBC cell proliferation and tumorigenic potential in a cooperative manner. A combination of PKC-α-MET inhibitors also attenuated tumor growth in a cooperative manner in vivo. Our findings define three kinases critical for TNBC growth and offer a preclinical rationale for their candidacy as effective therapeutic targets in treating TNBC.
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Affiliation(s)
- Yi-Hsin Hsu
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Jun Yao
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Li-Chuan Chan
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
| | - Ting-Jung Wu
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. Department of General Surgery, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taipei, Taiwan
| | - Jennifer L Hsu
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. Graduate Institute for Cancer Biology and Center for Molecular Medicine, China Medical University, Taichung, Taiwan. Department of Biotechnology, Asia University, Taichung, Taiwan
| | - Yueh-Fu Fang
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taipei, Taiwan
| | - Yongkun Wei
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Yun Wu
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Wen-Chien Huang
- Department of Surgery, Mackay Memorial Hospital, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan
| | - Chien-Liang Liu
- Department of Surgery, Mackay Memorial Hospital, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan
| | - Yuan-Ching Chang
- Department of Surgery, Mackay Memorial Hospital, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan
| | - Ming-Yang Wang
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
| | - Chia-Wei Li
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Jia Shen
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
| | - Mei-Kuang Chen
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
| | - Aysegul A Sahin
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Anil Sood
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas. Department of Gynecologic Oncology and Reproductive Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Gordon B Mills
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas. Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Dihua Yu
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas
| | - Gabriel N Hortobagyi
- Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Mien-Chie Hung
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas. Graduate Institute for Cancer Biology and Center for Molecular Medicine, China Medical University, Taichung, Taiwan. Department of Biotechnology, Asia University, Taichung, Taiwan.
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20
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Wallace JA, Pitarresi JR, Sharma N, Palettas M, Cuitiño MC, Sizemore ST, Yu L, Sanderlin A, Rosol TJ, Mehta KD, Sizemore GM, Ostrowski MC. Protein kinase C Beta in the tumor microenvironment promotes mammary tumorigenesis. Front Oncol 2014; 4:87. [PMID: 24795864 PMCID: PMC4006052 DOI: 10.3389/fonc.2014.00087] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 04/08/2014] [Indexed: 02/04/2023] Open
Abstract
Protein kinase C beta (PKCβ) expression in breast cancer is associated with a more aggressive tumor phenotype, yet the mechanism for how PKCβ is pro-tumorigenic in this disease is still unclear. Interestingly, while it is known that PKCβ mediates angiogenesis, immunity, fibroblast function and adipogenesis, all components of the mammary tumor microenvironment (TME), no study to date has investigated whether stromal PKCβ is functionally relevant in breast cancer. Herein, we evaluate mouse mammary tumor virus–polyoma middle T-antigen (MMTV–PyMT) induced mammary tumorigenesis in the presence and absence of PKCβ. We utilize two model systems: one where PKCβ is deleted in both the epithelial and stromal compartments to test the global requirement for PKCβ on tumor formation, and second, where PKCβ is deleted only in the stromal compartment to test its role in the TME. MMTV–PyMT mice globally lacking PKCβ live longer and develop smaller tumors with decreased proliferation and decreased macrophage infiltration. Similarly, when PKCβ is null exclusively in the stroma, PyMT-driven B6 cells form smaller tumors with diminished collagen deposition. These experiments reveal for the first time a tumor promoting role for stromal PKCβ in MMTV–PyMT tumorigenesis. In corroboration with these results, PKCβ mRNA (Prkcb) is increased in fibroblasts isolated from MMTV–PyMT tumors. These data were confirmed in a breast cancer patient cohort. Combined these data suggest the continued investigation of PKCβ in the mammary TME is necessary to elucidate how to effectively target this signaling pathway in breast cancer.
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Affiliation(s)
- Julie A Wallace
- Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University , Columbus, OH , USA ; Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA
| | - Jason R Pitarresi
- Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University , Columbus, OH , USA ; Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA
| | - Nandini Sharma
- Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University , Columbus, OH , USA ; Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA
| | - Marilly Palettas
- Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University , Columbus, OH , USA ; Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA
| | - Maria C Cuitiño
- Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA
| | - Steven T Sizemore
- Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA ; Department of Radiation Oncology, The Ohio State University , Columbus, OH , USA
| | - Lianbo Yu
- Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA ; Center for Biostatistics, The Ohio State University , Columbus, OH , USA
| | - Allen Sanderlin
- Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University , Columbus, OH , USA ; Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA
| | - Thomas J Rosol
- Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA ; Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University , Columbus, OH , USA
| | - Kamal D Mehta
- Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University , Columbus, OH , USA
| | - Gina M Sizemore
- Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University , Columbus, OH , USA ; Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA
| | - Michael C Ostrowski
- Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University , Columbus, OH , USA ; Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA
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21
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Yun J, Pannuti A, Espinoza I, Zhu H, Hicks C, Zhu X, Caskey M, Rizzo P, D'Souza G, Backus K, Denning MF, Coon J, Sun M, Bresnick EH, Osipo C, Wu J, Strack PR, Tonetti DA, Miele L. Crosstalk between PKCα and Notch-4 in endocrine-resistant breast cancer cells. Oncogenesis 2013; 2:e60. [PMID: 23917222 PMCID: PMC3759125 DOI: 10.1038/oncsis.2013.26] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 06/14/2013] [Accepted: 06/19/2013] [Indexed: 12/23/2022] Open
Abstract
The Notch pathway is functionally important in breast cancer. Notch-1 has been reported to maintain an estrogen-independent phenotype in estrogen receptor α (ERα)+ breast cancer cells. Notch-4 expression correlates with Ki67. Notch-4 also plays a key role in breast cancer stem-like cells. Estrogen-independent breast cancer cell lines have higher Notch activity than estrogen-dependent lines. Protein kinase Cα (PKCα) overexpression is common in endocrine-resistant breast cancers and promotes tamoxifen (TAM)-resistant growth in breast cancer cell lines. We tested whether PKCα overexpression affects Notch activity and whether Notch signaling contributes to endocrine resistance in PKCα-overexpressing breast cancer cells.Analysis of published microarray data from ERα+ breast carcinomas shows that PKCα expression correlates strongly with Notch-4. Real-time reverse transcription PCR and immunohistochemistry on archival specimens confirmed this finding. In a PKCα-overexpressing, TAM-resistant T47D model, PKCα selectively increases Notch-4, but not Notch-1, expression in vitro and in vivo. This effect is mediated by activator protein-1 (AP-1) occupancy of the Notch-4 promoter. Notch-4 knockdown inhibits estrogen-independent growth of PKCα-overexpressing T47D cells, whereas Notch-4IC expression stimulates it. Gene expression profiling shows that multiple genes and pathways associated with endocrine resistance are induced in Notch-4IC- and PKCα-expressing T47D cells. In PKCα-overexpressing T47D xenografts, an orally active γ-secretase inhibitor at clinically relevant doses significantly decreased estrogen-independent tumor growth, alone and in combination with TAM. In conclusion, PKCα overexpression induces Notch-4 through AP-1. Notch-4 promotes estrogen-independent, TAM-resistant growth and activates multiple pathways connected with endocrine resistance and chemoresistance. Notch inhibitors should be clinically evaluated in PKCα- and Notch-4-overexpressing, endocrine-resistant breast cancers.
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Affiliation(s)
- J Yun
- Cardinal Bernardin Cancer Center and Department of Pathology, Loyola University Chicago, Maywood, IL, USA
| | - A Pannuti
- Cancer Institute, University of Mississippi Medical Center, Jackson, MS, USA
| | - I Espinoza
- Cancer Institute, University of Mississippi Medical Center, Jackson, MS, USA
| | - H Zhu
- Cancer Institute, University of Mississippi Medical Center, Jackson, MS, USA
| | - C Hicks
- Cancer Institute, University of Mississippi Medical Center, Jackson, MS, USA
| | - X Zhu
- Cancer Institute, University of Mississippi Medical Center, Jackson, MS, USA
| | - M Caskey
- Cancer Institute, University of Mississippi Medical Center, Jackson, MS, USA
| | - P Rizzo
- Cardinal Bernardin Cancer Center and Department of Pathology, Loyola University Chicago, Maywood, IL, USA
| | - G D'Souza
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - K Backus
- Cancer Institute, University of Mississippi Medical Center, Jackson, MS, USA
| | - M F Denning
- Cardinal Bernardin Cancer Center and Department of Pathology, Loyola University Chicago, Maywood, IL, USA
| | - J Coon
- Department of Pathology, Rush University Chicago, Chicago, IL, USA
| | - M Sun
- Department of Cancer Biology, University of Chicago, Chicago, IL, USA
| | - E H Bresnick
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI, USA
| | - C Osipo
- Cardinal Bernardin Cancer Center and Department of Pathology, Loyola University Chicago, Maywood, IL, USA
| | - J Wu
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI, USA
| | - P R Strack
- Merck Research Laboratories, Boston, MA, USA
| | - D A Tonetti
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - L Miele
- Cancer Institute, University of Mississippi Medical Center, Jackson, MS, USA
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22
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Liu KC, Ge W. Evidence for gating roles of protein kinase A and protein kinase C in estradiol-induced luteinizing hormone receptor (lhcgr) expression in zebrafish ovarian follicle cells. PLoS One 2013; 8:e62524. [PMID: 23658740 PMCID: PMC3643932 DOI: 10.1371/journal.pone.0062524] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 03/22/2013] [Indexed: 11/18/2022] Open
Abstract
Estradiol (E2) stimulates luteinizing hormone receptor (lhcgr) expression in zebrafish follicle cells via nuclear estrogen receptors (nERs) that are likely expressed on the membrane, and lhcgr responds to E2 in a biphasic manner during 24-h treatment. These observations raise an interesting question on the signaling mechanism underlying E2 regulation, in particular the biphasic response of lhcgr expression. In the present study, we demonstrated that E2 regulation of lhcgr was significantly influenced by the activity of cAMP-PKA pathway. Activation of cAMP-PKA pathway by forskolin or db-cAMP suppressed E2-stimulated lhcgr expression in short-term (3 h) but enhanced its effect in long-term (24 h), suggesting differential roles of PKA at these two phases of lhcgr response. PKA inhibitor H89 showed reversed effects. In contrast, PKC pathway had consistent permissive effect on E2-induced lhcgr expression as evidenced by strong inhibition of E2 effect by PKC inhibitors GF109203X and Ro-31-8220 at both 3 and 24 h. One of the mechanisms by which PKA and PKC gated E2 effect might be through regulating nERs, particularly esr2a. Despite the strong influence of PKA and PKC, our data did not suggest direct mediating roles for these two pathways in E2 stimulation of lhcgr expression; yet they likely play critical gating roles in E2 signal transduction. As a follow-up study to our previous report on E2 regulation of gonadotropin receptors in the zebrafish ovary, the present study provides further evidence for the involvement of classical intracellular signal transduction pathways in E2 stimulation of lhcgr expression in the follicle cells.
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Affiliation(s)
- Ka-Cheuk Liu
- School of Life Sciences and Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Wei Ge
- School of Life Sciences and Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- * E-mail:
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23
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Perez White B, Molloy ME, Zhao H, Zhang Y, Tonetti DA. Extranuclear ERα is associated with regression of T47D PKCα-overexpressing, tamoxifen-resistant breast cancer. Mol Cancer 2013; 12:34. [PMID: 23634843 PMCID: PMC3661391 DOI: 10.1186/1476-4598-12-34] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 04/26/2013] [Indexed: 01/22/2023] Open
Abstract
Background Prior to the introduction of tamoxifen, high dose estradiol was used to treat breast cancer patients with similar efficacy as tamoxifen, albeit with some undesirable side effects. There is renewed interest to utilize estradiol to treat endocrine resistant breast cancers, especially since findings from several preclinical models and clinical trials indicate that estradiol may be a rational second-line therapy in patients exhibiting resistance to tamoxifen and/or aromatase inhibitors. We and others reported that breast cancer patients bearing protein kinase C alpha (PKCα)- expressing tumors exhibit endocrine resistance and tumor aggressiveness. Our T47D:A18/PKCα preclinical model is tamoxifen-resistant, hormone-independent, yet is inhibited by 17β-estradiol (E2) in vivo. We previously reported that E2-induced T47D:A18/PKCα tumor regression requires extranuclear ERα and interaction with the extracellular matrix. Methods T47D:A18/PKCα cells were grown in vitro using two-dimensional (2D) cell culture, three-dimensional (3D) Matrigel and in vivo by establishing xenografts in athymic mice. Immunofluoresence confocal microscopy and co-localization were applied to determine estrogen receptor alpha (ERα) subcellular localization. Co-immunoprecipitation and western blot were used to examine interaction of ERα with caveolin-1. Results We report that although T47D:A18/PKCα cells are cross-resistant to raloxifene in cell culture and in Matrigel, raloxifene induces regression of tamoxifen-resistant tumors. ERα rapidly translocates to extranuclear sites during T47D:A18/PKCα tumor regression in response to both raloxifene and E2, whereas ERα is primarily localized in the nucleus in proliferating tumors. E2 treatment induced complete tumor regression whereas cessation of raloxifene treatment resulted in tumor regrowth accompanied by re-localization of ERα to the nucleus. T47D:A18/neo tumors that do not overexpress PKCα maintain ERα in the nucleus during tamoxifen-mediated regression. An association between ERα and caveolin-1 increases in tumors regressing in response to E2. Conclusions Extranuclear ERα plays a role in the regression of PKCα-overexpressing tamoxifen-resistant tumors. These studies underline the unique role of extranuclear ERα in E2- and raloxifene-induced tumor regression that may have implications for treatment of endocrine-resistant PKCα-expressing tumors encountered in the clinic.
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Affiliation(s)
- Bethany Perez White
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, 833 S, Wood Street, Chicago, IL 60611, USA
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24
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Kim JA, Kim MR, Kim O, Phuong NTT, Yun J, Yoon J, Oh WK, Bae K, Kang KW. Amurensin G inhibits angiogenesis and tumor growth of tamoxifen-resistant breast cancer via Pin1 inhibition. Food Chem Toxicol 2012; 50:3625-34. [PMID: 22842120 DOI: 10.1016/j.fct.2012.07.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 07/16/2012] [Accepted: 07/18/2012] [Indexed: 02/07/2023]
Abstract
Acquired resistance to tamoxifen (TAM) is a serious therapeutic problem among estrogen-receptor-positive breast cancer patients. We have previously reported that TAM-resistant MCF-7 (TAMR-MCF-7) cells have elevated angiogenic potential via Pin1-dependent vascular endothelial growth factor (VEGF) production. Vitis amurensis grape consumed as wine and fruit contains several resveratrol-like stilbenes or oligostilbenes. In this study, we screened for the most active compound to inhibit VEGF production from V. amurensis. Among the tested compounds, amurensin G most potently suppressed VEGF production in TAMR-MCF-7 cells. The enhanced VEGF gene transcription in TAMR-MCF-7 cells was suppressed by amurensin G. Molecular analyses using reporter genes with hypoxia response elements and activator protein-1 (AP-1) elements, and western blots revealed that the activities and the nuclear levels of hypoxia inducible factor-1 (HIF-1)α and AP-1 in TAMR-MCF-7 cells were decreased by amurensin G. Moreover, amurensin G concentration-dependently inhibited protein expression and gene transcription of Pin1 in TAMR-MCF-7 cells, which was dependent on E2F1 inhibition. Chick chorioallantoic membrane assays confirmed that amurensin G had significant antiangiogenic and antitumor growth effects in TMAR-MCF-7 cells. These results demonstrate for the first time that amurensin G may have therapeutic potential for TAM-resistant breast cancer through blocking of Pin1-mediated VEGF gene transcription.
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Affiliation(s)
- Jung-Ae Kim
- College of Pharmacy, Yeungnam University, Daegu 712-749, Republic of Korea
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25
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Awadelkarim KD, Callens C, Rossé C, Susini A, Vacher S, Rouleau E, Lidereau R, Bièche I. Quantification of PKC family genes in sporadic breast cancer by qRT-PCR: evidence that PKCι/λ overexpression is an independent prognostic factor. Int J Cancer 2012; 131:2852-62. [PMID: 22511072 DOI: 10.1002/ijc.27600] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 04/05/2012] [Indexed: 11/11/2022]
Abstract
Drugs targeting protein kinase C (PKC) show promising therapeutic activity. However, little is known about the expression patterns of the 11 PKC genes in human tumors, and the clinical significance of most PKC genes is unknown. We used qRT-PCR assays to quantify mRNA levels of the 11 PKC genes in 458 breast tumors from patients with known clinical/pathological status and long-term outcome. The proportion of tumors in which the expression of the different genes was altered varied widely, from 9.6% for PKN2 to 40.2% for PKCι/λ. In breast tumors, overexpression was the main alteration observed for PKCι/λ (33.4%), PKCδ (29.5%) and PKCζ (9.6%), whereas underexpression was the main alteration observed for PKCα (27.3%), PKCε (11.6%), PKCη (8.7%) and PKN2 (8.1%). Both overexpression and underexpression were observed for PKCβ (underexpression 15.5%, overexpression 13.8%), PKCθ (underexpression 14.8%, overexpression 10.0%) and PKN1 (underexpression 6.6%, overexpression 7.4%). Several links were found between different PKC genes; and also between the expression patterns of PKC genes and several classical pathological and clinical parameters. PKCι/λ alone was found to have prognostic significance (p = 0.043), whereas PKCα showed a trend towards an influence on relapse-free survival (p = 0.052). PKCι/λ retained its prognostic significance in Cox multivariate regression analysis (p = 0.031). These results reveal very complex expression patterns of PKC genes in breast tumors, and suggest that their expression should be considered together when evaluating anti-tumoral drugs. PKCι/λ seems to be the most promising therapeutic target in breast cancer.
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26
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Protein kinase Cα suppresses the expression of STC1 in MDA-MB-231 breast cancer cells. Tumour Biol 2011; 32:1023-30. [PMID: 21720730 DOI: 10.1007/s13277-011-0205-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 06/15/2011] [Indexed: 10/18/2022] Open
Abstract
Several protein kinase C (PKC) isoforms have been shown to influence different cellular processes that may contribute to the malignancy of breast cancer cells. To obtain insight into mechanisms mediating the PKC effects, global gene expression was analyzed in MDA-MB-231 breast cancer cells in which PKCα, PKCδ or PKCε had been down-regulated with siRNA. Gene set enrichment analyses revealed that hypoxia-induced genes were enriched among genes that increased in PKCα-down-regulated cells. The STC1 mRNA, encoding stanniocalcin 1, was particularly up-regulated following depletion of PKCα and was also induced by hypoxia. Both hypoxia and PKCα down-regulation also led to increased STC1 protein levels. The results demonstrate that PKCα suppresses the expression of STC1 in breast cancer cells.
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27
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Lønne GK, Cornmark L, Zahirovic IO, Landberg G, Jirström K, Larsson C. PKCalpha expression is a marker for breast cancer aggressiveness. Mol Cancer 2010; 9:76. [PMID: 20398285 PMCID: PMC2873434 DOI: 10.1186/1476-4598-9-76] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Accepted: 04/14/2010] [Indexed: 11/23/2022] Open
Abstract
Background Protein kinase C (PKC) isoforms are potential targets for breast cancer therapy. This study was designed to evaluate which PKC isoforms might be optimal targets for different breast cancer subtypes. Results In two cohorts of primary breast cancers, PKCα levels correlated to estrogen and progesterone receptor negativity, tumor grade, and proliferative activity, whereas PKCδ and PKCε did not correlate to clinicopathological parameters. Patients with PKCα-positive tumors showed poorer survival than patients with PKCα-negative tumors independently of other factors. Cell line studies demonstrated that PKCα levels are high in MDA-MB-231 and absent in T47D cells which proliferated slower than other cell lines. Furthermore, PKCα silencing reduced proliferation of MDA-MB-231 cells. PKCα inhibition or downregulation also reduced cell migration in vitro. Conclusions PKCα is a marker for poor prognosis of breast cancer and correlates to and is important for cell functions associated with breast cancer progression.
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Affiliation(s)
- Gry Kalstad Lønne
- Center for Molecular Pathology, Department of Laboratory Medicine, Lund University, Malmö University Hospital, SE- 205 02 Malmö, Sweden.
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28
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Kim HY, Sohn J, Wijewickrama GT, Edirisinghe P, Gherezghiher T, Hemachandra M, Lu PY, Chandrasena RE, Molloy ME, Tonetti DA, Thatcher GRJ. Click synthesis of estradiol-cyclodextrin conjugates as cell compartment selective estrogens. Bioorg Med Chem 2009; 18:809-21. [PMID: 20031420 DOI: 10.1016/j.bmc.2009.11.046] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2009] [Revised: 11/16/2009] [Accepted: 11/21/2009] [Indexed: 01/15/2023]
Abstract
Cyclodextrin (CD) is a well known drug carrier and excipient for enhancing aqueous solubility. CDs themselves are anticipated to have low membrane permeability because of relatively high hydrophilicity and molecular weight. CD derivatization with 17-beta estradiol (E(2)) was explored extensively using a number of different click chemistries and the cell membrane permeability of synthetic CD-E(2) conjugate was explored by cell reporter assays and confocal fluorescence microscopy. In simile with reported dendrimer-E(2) conjugates, CD-E(2) was found to be a stable, extranuclear receptor selective estrogen that penetrated into the cytoplasm.
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Affiliation(s)
- Hye-Yeong Kim
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, IL 60612, United States
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29
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Lewis-Wambi JS, Jordan VC. Estrogen regulation of apoptosis: how can one hormone stimulate and inhibit? Breast Cancer Res 2009; 11:206. [PMID: 19519952 PMCID: PMC2716493 DOI: 10.1186/bcr2255] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The link between estrogen and the development and proliferation of breast cancer is well documented. Estrogen stimulates growth and inhibits apoptosis through estrogen receptor-mediated mechanisms in many cell types. Interestingly, there is strong evidence that estrogen induces apoptosis in breast cancer and other cell types. Forty years ago, before the development of tamoxifen, high-dose estrogen was used to induce tumor regression of hormone-dependent breast cancer in post-menopausal women. While the mechanisms by which estrogen induces apoptosis were not completely known, recent evidence from our laboratory and others demonstrates the involvement of the extrinsic (Fas/FasL) and the intrinsic (mitochondria) pathways in this process. We discuss the different apoptotic signaling pathways involved in E2 (17beta-estradiol)-induced apoptosis, including the intrinsic and extrinsic apoptosis pathways, the NF-kappaB (nuclear factor-kappa-B)-mediated survival pathway as well as the PI3K (phosphoinositide 3-kinase)/Akt signaling pathway. Breast cancer cells can also be sensitized to estrogen-induced apoptosis through suppression of glutathione by BSO (L-buthionine sulfoximine). This finding has implications for the control of breast cancer with low-dose estrogen and other targeted therapeutic drugs.
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Affiliation(s)
- Joan S Lewis-Wambi
- Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - V Craig Jordan
- Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
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30
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Zhang Y, Zhao H, Asztalos S, Chisamore M, Sitabkhan Y, Tonetti DA. Estradiol-induced regression in T47D:A18/PKCalpha tumors requires the estrogen receptor and interaction with the extracellular matrix. Mol Cancer Res 2009; 7:498-510. [PMID: 19372579 DOI: 10.1158/1541-7786.mcr-08-0415] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Several breast cancer tumor models respond to estradiol (E(2)) by undergoing apoptosis, a phenomenon known to occur in clinical breast cancer. Before the application of tamoxifen as an endocrine therapy, high-dose E(2) or diethystilbesterol treatment was successfully used, albeit with unfavorable side effects. It is now recognized that such an approach may be a potential endocrine therapy option. We have explored the mechanism of E(2)-induced tumor regression in our T47D:A18/PKCalpha tumor model that exhibits autonomous growth, tamoxifen resistance, and E(2)-induced tumor regression. Fulvestrant, a selective estrogen receptor (ER) down-regulator, prevents T47D:A18/PKCalpha E(2)-induced tumor growth inhibition and regression when given before or after tumor establishment, respectively. Interestingly, E(2)-induced growth inhibition is only observed in vivo or when cells are grown in Matrigel but not in two-dimensional tissue culture, suggesting the requirement of the extracellular matrix. Tumor regression is accompanied by increased expression of the proapoptotic FasL/FasL ligand proteins and down-regulation of the prosurvival Akt pathway. Inhibition of colony formation in Matrigel by E(2) is accompanied by increased expression of FasL and short hairpin RNA knockdown partially reverses colony formation inhibition. Classic estrogen-responsive element-regulated transcription of pS2, PR, transforming growth factor-alpha, C3, and cathepsin D is independent of the inhibitory effects of E(2). A membrane-impermeable E(2)-BSA conjugate is capable of mediating growth inhibition, suggesting the involvement of a plasma membrane ER. We conclude that E(2)-induced T47D:A18/PKCalpha tumor regression requires participation of ER-alpha, the extracellular matrix, FasL/FasL ligand, and Akt pathways, allowing the opportunity to explore new predictive markers and therapeutic targets.
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Affiliation(s)
- Yiyun Zhang
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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31
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Opposite effects of protein kinase C beta1 (PKCbeta1) and PKCepsilon in the metastatic potential of a breast cancer murine model. Breast Cancer Res Treat 2009; 118:469-80. [PMID: 19132529 DOI: 10.1007/s10549-008-0299-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Accepted: 12/24/2008] [Indexed: 01/04/2023]
Abstract
In this paper we investigated whether protein kinase C (PKC) beta1 and PKCepsilon, members of the classical and novel PKC family, respectively, induce phenotypic alterations that could be associated with tumor progression and metastatic dissemination in a murine model of breast cancer. Stable overexpression of PKCbeta1 in LM3 cells altered their ability to proliferate, adhere, and survive, and impaired their tumorigenicity and metastatic capacity. Moreover, PKCbeta1 induced the re-expression of fibronectin, an extracellular matrix glycoprotein which loss has been associated with the acquisition of a transformed phenotype in different cell models, and exerted an important inhibition on proteases production, effects that probably impact on LM3 invasiveness and dissemination. Conversely, PKCepsilon overexpression enhanced LM3 survival, anchorage-independent growth, and caused a significant increase in spontaneous lung metastasis. Our results suggest PKCbeta1 functions as an inhibitory protein for tumor growth and metastasis dissemination whereas PKCepsilon drives metastatic dissemination without affecting primary tumor growth.
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32
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Nkhata KJ, Ray A, Dogan S, Grande JP, Cleary MP. Mammary tumor development from T47-D human breast cancer cells in obese ovariectomized mice with and without estradiol supplements. Breast Cancer Res Treat 2008; 114:71-83. [PMID: 18392696 DOI: 10.1007/s10549-008-9991-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 03/24/2008] [Indexed: 11/29/2022]
Abstract
Obesity is a risk factor for postmenopausal breast cancer, particularly for development of estrogen-receptor (ER)-positive tumors. Additionally, obesity is implicated in breast cancer progression. However, few studies address mechanisms of action of how obesity mediates these responses. Our goal was to address how obesity and/or elevated serum leptin affects tumor formation from ER-positive T47-D cells. In Study 1 ovariectomized CD-1 nude female mice were injected with goldthioglucose (GTG) at 0.5 mg/g body weight in saline or the vehicle at 6 weeks of age. At 10 weeks of age mice were inoculated with T47-D cells and implanted with estrogen pellets. In Study 2 mice were injected with 0.3 mg/g GTG or the vehicle. At 10 weeks of age cells were inoculated and mice were implanted with estrogen or placebo pellets. Mice were followed until 30 weeks of age. Some GTG mice became obese and others were non-responders. In Study 1 no mice developed tumors. In Study 2 mice with placebo pellets developed more tumors than mice with estrogen pellets, 50% vs. 13%. GTG-obese mice with placebo pellets had a 100% tumor incidence compared to 50% and 20% for GTG-lean and controls without estrogen. Serum leptin was higher in obese compared to lean mice and adiponectin was not affected by body weight. Adiponectin:leptin ratio was significantly reduced in obese compared to lean mice. Leptin, leptin receptor and signaling protein expression were determined in mammary and tumor tissue. Leptin and STAT3 were most abundant in tumors. These findings suggest that in vivo estrogen suppressed proliferation of T47-D cells but without supplemental estrogen obesity enhanced tumor development. The exact reason for this is not presently clear.
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Affiliation(s)
- Katai J Nkhata
- Hormel Institute, University of Minnesota, 801 16th Avenue NE, Austin, MN 55912, USA
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Belguise K, Sonenshein GE. PKCtheta promotes c-Rel-driven mammary tumorigenesis in mice and humans by repressing estrogen receptor alpha synthesis. J Clin Invest 2008; 117:4009-21. [PMID: 18037997 DOI: 10.1172/jci32424] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Accepted: 09/19/2007] [Indexed: 12/14/2022] Open
Abstract
The vast majority of primary human breast cancer tissues display aberrant nuclear NF-kappaB c-Rel expression. A causal role for c-Rel in mammary tumorigenesis has been demonstrated using a c-Rel transgenic mouse model; however, tumors developed with a long latency, suggesting a second event is needed to trigger tumorigenesis. Here we show that c-Rel activity in the mammary gland is repressed by estrogen receptor alpha (ERalpha) signaling, and we identify an epigenetic mechanism in breast cancer mediated by activation of what we believe is a novel PKCtheta-Akt pathway that leads to downregulation of ERalpha synthesis and derepression of c-Rel. ERalpha levels were lower in c-Rel-induced mammary tumors compared with normal mammary gland tissue. PKCtheta induced c-Rel activity and target gene expression and promoted growth of c-Rel- and c-RelxCK2alpha-driven mouse mammary tumor-derived cell lines. RNA expression levels of PKCtheta and c-Rel target genes were inversely correlated with ERalpha levels in human breast cancer specimens. PKCtheta activated Akt, thereby inactivating forkhead box O protein 3a (FOXO3a) and leading to decreased synthesis of its target genes, ERalpha and p27(Kip1). Thus we have shown that activation of PKCtheta inhibits the FOXO3a/ERalpha/p27(Kip1) axis that normally maintains an epithelial cell phenotype and induces c-Rel target genes, thereby promoting proliferation, survival, and more invasive breast cancer.
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Affiliation(s)
- Karine Belguise
- Department of Biochemistry and Women's Health Interdisciplinary Research Center, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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34
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Assender JW, Gee JMW, Lewis I, Ellis IO, Robertson JFR, Nicholson RI. Protein kinase C isoform expression as a predictor of disease outcome on endocrine therapy in breast cancer. J Clin Pathol 2007; 60:1216-21. [PMID: 17965220 DOI: 10.1136/jcp.2006.041616] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Although in vitro breast cancer models have demonstrated a role for protein kinase C (PKC) alpha and delta isoforms in endocrine insensitivity and resistance respectively, there is currently little clinical evidence to support these observations. AIMS To define the pattern of PKC alpha and delta expression using breast cancer cell lines, with and without endocrine resistance, and also breast cancer samples, where expression can be correlated with clinicopathological and endocrine therapy outcome data. METHODS PKC isoform expression was examined in tamoxifen responsive, oestrogen receptor positive (ER(+)), ER(+) acquired tamoxifen resistant (TAM-R) and oestrogen receptor negative (ER(-)) cell lines by western blotting and immunocytochemical analysis. PKC isoform expression was then examined by immunohistochemistry in archival breast cancer specimens from primary breast cancer patients with known clinical outcome in relation to endocrine response and survival on therapy. RESULTS ER(+) breast cancer cell lines expressed considerable PKC-delta but barely detectable levels of PKC-alpha, whereas ER(-) cell lines expressed PKC-alpha but little PKC-delta. ER(+) acquired TAM-R cell lines expressed substantial levels of both PKC-alpha and delta. In clinical samples, high PKC-delta expression correlated to endocrine responsiveness whereas PKC-alpha expression correlated to ER negativity. PKC-delta was an independent predictor of duration of response to therapy. Patients showing a PKC-delta(+)/PKC-alpha(-) phenotype had a six times longer endocrine response than patients with the PKC-delta(+)/ PKC-alpha(+) phenotype (equating to tamoxifen resistance in vitro). CONCLUSIONS Levels of PKC-alpha and delta expression appear to be indicative of response to anti-oestrogen therapy and could be useful in predicting a patient's suitability for endocrine therapy.
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Affiliation(s)
- J W Assender
- CRUK Institute of Cancer Studies, University of Birmingham, Edgbaston, Birmingham, UK
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Grossoni VC, Falbo KB, Kazanietz MG, de Kier Joffé EDB, Urtreger AJ. Protein kinase C delta enhances proliferation and survival of murine mammary cells. Mol Carcinog 2007; 46:381-90. [PMID: 17219421 DOI: 10.1002/mc.20287] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Protein kinase C (PKC) delta, a member of the novel family of PKC serine-threonine kinases, has been implicated in negative regulation of proliferation and apoptosis in a large number of cell types, including breast cancer cell lines, and postulated as a tumor suppressor gene. In this study we show that in murine NMuMG mammary cells PKCdelta promotes a mitogenic response. Overexpression of PKCdelta in NMuMG cells leads to a significant increase in [3H]-tymidine incorporation and cell proliferation, as well as enhanced extracellular signal-regulated kinase (ERK)-mitogen-activated protein kinase (MAPK) activation. Activation of PKCdelta with a phorbol ester leads to elevated cyclin D1 expression and an hyperphosphorylated Rb state. Surprisingly, ectopic expression of PKCdelta conferred anchorage-independent growth capacity to NMuMG cells. PKCdelta overexpressors showed enhanced resistance to apoptotic stimuli, such as serum deprivation or doxorubicin treatment, an effect that correlates with hyperactivation of the Akt survival pathway. Our results provide evidence for a role of PKCdelta as a positive modulator of proliferative and survival signals in immortalized mammary cells. The fact that PKCdelta exerts differential responses depending on the cell context not only highlights the necessity to carefully understand the signaling events controlled by this PKC in each cell type but also suggests that we should be cautious in considering this kinase a target for cancer therapy.
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Affiliation(s)
- Valeria C Grossoni
- Research Area, Institute of Oncology Angel H. Roffo, University of Buenos Aires, Buenos Aires, Argentina
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36
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Grossoni VC, Falbo KB, Mauro LV, Krasnapolski MA, Kazanietz MG, Bal De Kier Joffé ED, Urtreger AJ. Protein kinase C delta inhibits the production of proteolytic enzymes in murine mammary cells. Clin Exp Metastasis 2007; 24:513-20. [PMID: 17653823 DOI: 10.1007/s10585-007-9088-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Accepted: 06/29/2007] [Indexed: 10/23/2022]
Abstract
In previous studies we have determined that protein kinase C (PKC) delta, a widely expressed member of the novel PKC serine-threonine kinases, induces in vitro changes associated with the acquisition of a malignant phenotype in NMuMG murine mammary cells. In this study we show that PKCdelta overexpression significantly decreases urokinase-type plasminogen activator (uPA) and matrix metalloproteinase-9 (MMP-9) production, two proteases associated with migratory and invasive capacities. This effect is markedly enhanced by treatment with phorbol 12-myristate 13-acetate (PMA). On the other hand, depletion of PKCdelta using RNAi led to a marked increase in both uPA and MMP-9 secretion, suggesting a physiological role for PKCdelta in controlling protease secretion. The MEK-1 inhibitor PD98059 reverted the characteristic pattern of proteases secretion and phospho-ERK1/2 up-regulation observed in PKCdelta overexpressors, suggesting that the PKCdelta effect is mediated by the MEK/ERK pathway. Our results suggest a dual role for PKCdelta in murine mammary cell cancer progression. While this kinase clearly promotes mitogenesis and favors malignant transformation, it also down-modulates the secretion of proteases probably limiting metastatic dissemination.
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Affiliation(s)
- Valeria C Grossoni
- Research Area, Institute of Oncology Angel H. Roffo, University of Buenos Aires, Av. San Martín 5481, Buenos Aires C1417DTB, Argentina
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37
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Vendrell JA, Ghayad S, Ben-Larbi S, Dumontet C, Mechti N, Cohen PA. A20/TNFAIP3, a new estrogen-regulated gene that confers tamoxifen resistance in breast cancer cells. Oncogene 2007; 26:4656-67. [PMID: 17297453 DOI: 10.1038/sj.onc.1210269] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The zinc-finger protein A20/TNFAIP3, an inhibitor of nuclear factor-kappaB (NF-kappaB) activation, has been shown to protect MCF-7 breast carcinoma cells from TNFalpha-induced apoptosis. As estrogen receptor (ER) status is an important parameter in the development and progression of breast cancer, we analysed the effect of 17beta-estradiol (E2) treatment on the expression of A20. We found that A20 is a new E2-regulated gene, whose expression correlates with ER expression in both cell lines and tumor samples. With the aim of investigating the impact of A20 expression on MCF-7 cells in response to ER ligands, we established stably transfected-MCF-7 cells overexpressing A20 (MCF-7-A20). These cells exhibited a phenotype of resistance to the 4-hydroxy-tamoxifen cytostatic and pro-apoptotic actions and of hyper-response to E2. Dysregulations in bax, bcl2, bak, phospho-bad, cyclin D1, cyclin E2, cyclin D2 and cyclin A2 proteins expression were shown to be related to the resistant phenotype developed by the MCF-7-A20 cells. Interestingly, we found that A20 was also overexpressed in MVLN and VP tamoxifen-resistant cell lines. Furthermore, high A20 expression levels were observed in more aggressive breast tumors (ER-negative, progesterone receptor-negative and high histological grade). These overall findings strongly suggest that A20 is a key protein involved in tamoxifen resistance, and thus represents both a new breast cancer marker and a promising target for developing new strategies to prevent the emergence of acquired mechanisms of drug resistance in breast cancer.
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Affiliation(s)
- J A Vendrell
- CNRS UMR 5160, Centre de Pharmacologie et Biotechnologie pour la Santé, Faculté de Pharmacie, Montpellier, France
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Abstract
Hormonal ligands for the nuclear receptor superfamily have at least two interacting mechanisms of action: 1) classical transcriptional regulation of target genes (genomic mechanisms); and 2) nongenomic actions that are initiated at the cell membrane, which could impact transcription. Although transcriptional mechanisms are increasingly well understood, membrane-initiated actions of these ligands are incompletely understood. Historically, this has led to a considerable divergence of thought in the molecular endocrine field. We have attempted to uncover principles of hormone action that are relevant to membrane-initiated actions of estrogens. There is evidence that the membrane-limited actions of hormones, particularly estrogens, involve the rapid activation of kinases and the release of calcium. Membrane actions of estrogens, which activate these rapid signaling cascades, can also potentiate nuclear transcription. These signaling cascades may occur in parallel or in series but subsequently converge at the level of modification of transcriptionally relevant molecules such as nuclear receptors and/or coactivators. In addition, other hormones or neurotransmitters may also activate cascades to crosstalk with estrogen receptor-mediated transcription. The idea of synergistic coupling between membrane-initiated and genomic actions of hormones fundamentally revises the paradigms of cell signaling in neuroendocrinology.
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Affiliation(s)
- Nandini Vasudevan
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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Tonetti DA, Zhang Y, Zhao H, Lim SB, Constantinou AI. The effect of the phytoestrogens genistein, daidzein, and equol on the growth of tamoxifen-resistant T47D/PKC alpha. Nutr Cancer 2007; 58:222-9. [PMID: 17640169 DOI: 10.1080/01635580701328545] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Soy supplements are often consumed by women for alleviating menopausal symptoms or for the perceived protective effects against breast cancer. More concerning is the concurrent consumption of soy isoflavones with tamoxifen (TAM) for prevention or treatment of breast cancer. We previously described a T47D:A18/protein kinase C (PKC)alpha TAM-resistant tumor model that exhibits autonomous growth and estradiol-induced tumor regression. We compared the estrogenicity of the isoflavones genistein, daidzein, and the daidzein metabolite equol in the parental T47D:A18 and T47D:A18/PKC alpha cell lines in vitro and in vivo. Whereas equol exerts estrogenic effects on T47D:A18 cells in vitro, none of the isoflavones stimulated T47D:A18 tumor growth. T47D:A18/PKC alpha tumor growth was partially stimulated by genistein, yet partially inhibited by daidzein. Interestingly, coadministration of TAM with either daidzein or genistein produced tumors of greater size than with TAM alone. These findings suggest that simultaneous consumption of isoflavone supplements with TAM may not be safe.
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Affiliation(s)
- Debra A Tonetti
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA.
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40
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Frankel LB, Lykkesfeldt AE, Hansen JB, Stenvang J. Protein Kinase C alpha is a marker for antiestrogen resistance and is involved in the growth of tamoxifen resistant human breast cancer cells. Breast Cancer Res Treat 2006; 104:165-79. [PMID: 17061041 DOI: 10.1007/s10549-006-9399-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Accepted: 09/01/2006] [Indexed: 01/11/2023]
Abstract
Development of resistance to antiestrogen treatment in breast cancer patients is a serious therapeutic problem. The molecular mechanisms contributing to resistance are currently unclear; however it is known that increased activation of growth signaling pathways is involved. Protein Kinase C alpha (PKCalpha) is associated with a diverse range of cancers and is previously shown to be overexpressed in three out of four antiestrogen resistant breast cancer cell lines. In this study we investigated whether PKCalpha contributes to antiestrogen resistant growth. A panel of nine resistant cell lines was investigated, all of which displayed elevated levels of PKCalpha expression relative to parental MCF-7 cells. Stable PKCalpha overexpression in MCF-7 cells significantly reduced sensitivity to the antiestrogens, tamoxifen and ICI 182,780. Two resistant cell lines were chosen for further studies: tamoxifen resistant MCF-7/TAM(R)-1 (TAM(R)-1) and ICI 182,780 resistant MCF-7/182(R)-6 (182(R)-6). Treatment with the PKCalpha inhibitor Ro-32-0432 resulted in a preferential growth inhibition of these two cell lines relative to MCF-7 cells. Moreover, transient down-regulation of PKCalpha resulted in a 30-40% growth inhibition of TAM(R)-1 and 182(R)-6, while MCF-7 remained unaffected. Stable PKCalpha knock-down in TAM(R)-1 using small hairpin RNA, resulted in a tamoxifen sensitive "MCF-7-like" growth phenotype, while the same approach in 182(R)-6 cells did not alter their sensitivity to ICI 182,780. These results demonstrate a functional contribution of PKCalpha to tamoxifen resistant growth. Furthermore, our data suggest the potential for PKCalpha as a marker for antiestrogen resistance and as a promising therapeutic target in the treatment of tamoxifen resistant breast cancer.
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Affiliation(s)
- Lisa B Frankel
- Department of Tumor Endocrinology, Institute of Cancer Biology, Danish Cancer Society, Strandboulevarden 49, 2100 Copenhagen, Denmark
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41
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Tari AM, Simeone AM, Li YJ, Gutierrez-Puente Y, Lai S, Symmans WF. Cyclooxygenase-2 protein reduces tamoxifen and N-(4-hydroxyphenyl)retinamide inhibitory effects in breast cancer cells. J Transl Med 2005; 85:1357-67. [PMID: 16127422 DOI: 10.1038/labinvest.3700339] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Approximately 30-40% of estrogen receptor alpha (ERalpha)-positive breast tumors express high levels of the cyclooxygenase-2 (COX-2) protein, and these high levels have been associated with a poorer prognosis in breast cancer patients. We speculate that high levels of COX-2 induce drug resistance in ERalpha-positive breast tumors, thus reducing the survival rate of patients with such tumors. Human breast cancer cell lines that express high levels of COX-2 are generally ERalpha negative. To determine whether COX-2 induces drug resistance, plasmids encoding the COX-2 gene were stably transfected into ERalpha-positive MCF-7 human breast cancer cells (MCF-7/COX-2). MCF-7/COX-2 cells were resistant to the selective estrogen receptor modulator tamoxifen but not to its analog, raloxifene. MCF-7/COX-2 cells were also resistant to the retinoid N-(4-hydroxyphenyl)retinamide (4-HPR) but not to its analog, all-trans retinoic acid. In contrast, the sensitivities of MCF-7/COX-2 cells to doxorubicin and paclitaxel were similar to those of the parental MCF-7 cells. We then determined which COX-2 product, prostaglandin E2 (PGE2) or prostaglandin F2alpha is involved in the COX-2-mediated drug resistance. PGE2, but not PGF2alpha, blocked the antiproliferative effects of tamoxifen and 4-HPR. Agonists that activate PGE2 receptors and their downstream kinase effectors, protein kinases A and C, also blocked the growth inhibitory effects of these drugs. Increased levels of Bcl-2 and Bcl-XL proteins have been reported in mammary tumors of COX-2 transgenic mice and in human colon cancer cell lines that have high levels of COX-2. However, we did not observe any changes in Bcl-2, Bcl-XL, or Bax expression induced by COX-2 or PGE2. Here we report the novel findings that COX-2 uses PGE2 to stimulate the activities of protein kinases A and C to induce selectively tamoxifen and 4-HPR resistance in ERalpha-positive breast cancer cells.
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Affiliation(s)
- Ana M Tari
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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42
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De Servi B, Hermani A, Medunjanin S, Mayer D. Impact of PKCdelta on estrogen receptor localization and activity in breast cancer cells. Oncogene 2005; 24:4946-55. [PMID: 15824731 DOI: 10.1038/sj.onc.1208676] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Regulation of estrogen receptor (ER) function in breast cancer cells is a complex process involving different signalling mechanisms. One signal transduction component that appears to influence ER signalling is protein kinase C (PKC). PKCdelta is a particular isoenzyme of the novel PKC subfamily that plays a role in growth control, differentiation and apoptosis. The aim of the present study was to investigate the impact of PKCdelta on the regulation of the transcriptional activity of the human ERalpha. By using 12-O-tetradecanoylphorbol-13-acetate (TPA), Bryostatin1 and Rottlerin, we show that active PKCdelta is a proproliferative factor in estrogen-dependent breast cancer cells. Furthermore, activation of PKCdelta by TPA resulted in activation and nuclear translocation of ERalpha and in an increase of ER-dependent reporter gene expression. Transfection and expression of the regulatory domain RDdelta of PKCdelta, which is inhibitory to PKCdelta, inhibited the TPA-induced ERalpha activation and translocation. ERalpha was not phosphorylated by PKCdelta; however, glycogen synthase kinase-3 (GSK3) was identified as a substrate of PKCdelta. The expression of RDdelta resulted in a decrease of TPA-induced GSK3 phosphorylation and translocation into the nucleus. We suggest that GSK3 plays a role in the PKCdelta-related nuclear translocation of ERalpha.
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Affiliation(s)
- Barbara De Servi
- Deutsches Krebsforschungszentrum, Hormones and Signal Transduction, Im Neuenheimer Feld 280, Heidelberg 69120, Germany
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43
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Nabha SM, Glaros S, Hong M, Lykkesfeldt AE, Schiff R, Osborne K, Reddy KB. Upregulation of PKC-delta contributes to antiestrogen resistance in mammary tumor cells. Oncogene 2005; 24:3166-76. [PMID: 15735693 DOI: 10.1038/sj.onc.1208502] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Acquired resistance to tamoxifen (Tam) in breast cancer patients is a serious therapeutic problem. We have previously reported that protein kinase C-delta (PKC-delta) plays a major role in estrogen (E2)-mediated cell proliferation. To determine if PKC-delta is one of the major alternate signaling pathways that supports cell growth in the presence of Tam, we determined the levels of PKC isoforms in four different models of antiestrogen-resistant cells. Three out of four antiestrogen resistance cell lines (Tam/MCF-7, ICI/MCF-7 and HER-2/MCF-7) expressed significantly high levels of both total and activated PKC-delta levels compared to sensitive cells. Estrogen receptor (ER) alpha content and function are maintained in all the antiestrogen-resistant cell lines. Overexpressing active PKC-delta in Tam-sensitive MCF-7 cells (PKC-delta/MCF-7) led to Tam resistance both in vitro and in vivo. Inhibition of PKC-delta by rottlerin (a relatively specific inhibitor of PKC-delta) or siRNA significantly inhibited estrogen- and Tam-induced growth in antiestrogen-resistant cells. PKC-delta levels are significantly higher in Tam-resistant tumors compared to Tam-sensitive tumors in xenograft model (P<0.05). Taken together, these data suggest that PKC-delta plays a major role in antiestrogen resistance in breast tumor cells and thus provides a new target for treatment.
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Affiliation(s)
- Sanaa M Nabha
- Department of Pathology, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI 48201, USA
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Yokoyama G, Fujii T, Tayama K, Yamana H, Kuwano M, Shirouzu K. PKCdelta and MAPK mediate G(1) arrest induced by PMA in SKBR-3 breast cancer cells. Biochem Biophys Res Commun 2005; 327:720-6. [PMID: 15649406 DOI: 10.1016/j.bbrc.2004.12.070] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Indexed: 10/26/2022]
Abstract
The effects of activating endogenous protein kinase C (PKC) on cell proliferation and the cell cycle were investigated by treating the breast cancer cell line SKBR-3 with phorbol 12-myristate 13 acetate (PMA). This inhibited cell growth in a concentration-dependent manner, causing a marked arrest of cells in G(1). Pre-treatment with GF109203X completely blocked the antiproliferative effect of PMA, and pre-treatment with the PKCdelta inhibitor rottlerin partially blocked it. Infecting SKBR-3 cells with an adenovirus vector containing wild-type PKCdelta, WTPKCdeltaAdV, had similar effects on PMA. Infecting the cells with a dominant-negative PKCdeltaAdV construct blocked the growth inhibition induced by PMA. Downstream of PKC, PMA treatment inhibited extracellular signal-regulated kinase mitogen-activated protein kinase phosphorylation, up-regulated c-jun NH(2)-terminal kinase phosphorylation, and inhibited retinoblastoma (Rb) phosphorylation. These results strongly implicated PKC (mainly PKCdelta) in the G(1) arrest induced by PMA and suggested PKC as a target for breast cancer treatment.
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Affiliation(s)
- Goro Yokoyama
- Department of Surgery, Kurume University School of Medicine, 67 Asahimachi, Fukuoka 830-0011, Japan
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45
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Sakwe AM, Rask L, Gylfe E. Protein Kinase C Modulates Agonist-sensitive Release of Ca2+ from Internal Stores in HEK293 Cells Overexpressing the Calcium Sensing Receptor. J Biol Chem 2005; 280:4436-41. [PMID: 15572354 DOI: 10.1074/jbc.m411686200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study examined the mechanism of Ca2+ entry and the role of protein kinase C (PKC) in Ca2+ signaling induced by activation of the calcium sensing receptor (CaR) in HEK293 cells stably expressing the CaR. We demonstrate that influx of Ca2+ following CaR activation exhibits store-operated characteristics in being associated with Ca2+ store depletion and inhibited by 2-aminoethoxydiphenyl borate. Inhibition of PKC with GF109203X, Go6983, or Go6976 and down-regulation of PKC activity enhanced the release of Ca2+ from internal stores in response to the polyvalent cationic CaR agonist neomycin, whereas activation of PKC with acute 12-O-tetradecanoylphorbol-13-acetate treatment decreased the release. In contrast, overexpression of wild type PKC-alpha or -epsilon augmented the neomycin-induced release of Ca2+ from internal stores, whereas dominant negative PKC-epsilon strongly decreased the release, but dominant negative PKC-alpha had little effect. Prolonged treatment of cells with 12-O-tetradecanoylphorbol-13-acetate effectively down-regulated immunoreactive PKC-alpha but had little effect on the expression of PKC-epsilon. Together these results indicate that diacylglycerol-responsive PKC isoforms differentially influence CaR agonist-induced release of Ca2+ from internal stores. The fundamentally different results obtained when overexpressing or functionally down-regulating specific PKC isoforms as compared with pharmacological manipulation of PKC activity indicate the need for caution when interpreting data obtained with the latter approach.
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Affiliation(s)
- Amos M Sakwe
- Department of Medical Biochemistry and Microbiology, Uppsala University, Biomedical Centre, Box 582, SE-751 23 Uppsala, Sweden
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46
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Urtreger AJ, Grossoni VC, Falbo KB, Kazanietz MG, Bal de Kier Joffé ED. Atypical protein kinase C-zeta modulates clonogenicity, motility, and secretion of proteolytic enzymes in murine mammary cells. Mol Carcinog 2005; 42:29-39. [PMID: 15546134 DOI: 10.1002/mc.20066] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In this paper, we investigated whether protein kinase C-zeta (PKC zeta), a member of the atypical PKC family, induces phenotypic alterations associated with malignant transformation and tumor progression in mammary cells. The stable overexpression of PKC zeta in immortalized mammary epithelial cells (NMuMG), activates the mitogenic extracellular signal-regulated kinase (ERK) pathway, enhanced clonal cell growth and exerts profound effects on proteases secretion. The effect on proteases expression seems to be specific for urokinase-type plasminogen activator and metalloproteinase-9 (MMP-9) because no modulation in MMP-2 and MMP-3 production could be detected. In addition, our experiments demonstrated that PKC zeta overexpression markedly altered the adhesive, spreading, and migratory abilities of NMuMG cells. The overexpression of this enzyme was not sufficient to confer an anchorage-independent growth capacity. An extensive mutational analysis of PKC zeta revealed that the effects observed in NMuMG cells were strictly dependent on the kinase (catalytic) domain of the enzyme. Taken together, these results suggest that in mammary cells PKC zeta modulates several of the critical events involved in tumor development and dissemination through the activation of mitogen activated protein kinase (MAPK)/ERK pathway.
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Affiliation(s)
- Alejandro J Urtreger
- Research Area, Institute of Oncology Angel H. Roffo, University of Buenos Aires, C1417DTB Buenos Aires, Argentina
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Braun DC, Cao Y, Wang S, Garfield SH, Min Hur G, Blumberg PM. Role of phorbol ester localization in determining protein kinase C or RasGRP3 translocation: Real-time analysis using fluorescent ligands and proteins. Mol Cancer Ther 2005. [DOI: 10.1158/1535-7163.141.4.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The diacylglycerol signaling pathway, involving protein kinase C (PKC) and RasGRP, is a promising therapeutic target for both cancer and other indications. The phorbol esters, ultrapotent diacylglycerol analogues, bind to and activate PKC and RasGRP. Here, using fluorescent phorbol esters and complementary fluorescent PKC and RasGRP constructs, we determined the localization of the phorbol ester as a function of time after addition and how the resultant PKC or RasGRP3 translocation related to ligand localization. For these studies, we prepared fluorescently labeled phorbol esters of varying lipophilicities based on the BODIPY FL (green) or BODIPY 581/591 (red) fluorophores, and by using fusion constructs of green fluorescent protein or DsRed with PKC isoforms or RasGRP3 expressed in Chinese hamster ovary cells, we simultaneously compared the kinetics and pattern of localization of PKC or RasGRP3 with that of the fluorescent red or green phorbol esters. Binding assays showed that the fluorescent derivatives were potent ligands. Uptake followed a one-compartment pharmacokinetic model with a half-time of minutes to hours, depending on the ligand, and all of the fluorescent phorbol esters localized primarily to intracellular membranes, with little plasma membrane localization. The fluorescent phorbol esters induced translocation of and generally colocalized with PKCδ or RasGRP3. However, PKCα and, initially, PKCδ, translocated to the plasma membrane, in which little phorbol ester accumulated. The findings argue that the rate of uptake of phorbol esters influences the subsequent pattern of PKCδ translocation, and that the specificity for PKCα translocation is dominated by factors other than the localization of the ligand.
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Affiliation(s)
- Derek C. Braun
- 1Department of Biology, Gallaudet University, Washington, District of Columbia; Laboratories of
- 2Cellular Carcinogenesis and Tumor Promotion and
| | - Yeyu Cao
- 4Departments of Internal Medicine and Medicinal Chemistry and Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan
| | - Shaomeng Wang
- 4Departments of Internal Medicine and Medicinal Chemistry and Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan
| | - Susan H. Garfield
- 3Experimental Carcinogenesis, National Cancer Institute, NIH, Bethesda, Maryland
| | - Gang Min Hur
- 2Cellular Carcinogenesis and Tumor Promotion and
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Lahn M, Köhler G, Sundell K, Su C, Li S, Paterson BM, Bumol TF. Protein kinase C alpha expression in breast and ovarian cancer. Oncology 2004; 67:1-10. [PMID: 15459489 DOI: 10.1159/000080279] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2003] [Accepted: 01/19/2004] [Indexed: 11/19/2022]
Abstract
In recent years research has focused on the development of specific, targeted drugs to treat cancer. One approach has been to block intracellular signaling proteins, such as protein kinase C alpha (PKC-alpha). To help support the rationale for clinical studies of a PKC-alpha-targeted therapy in breast and ovarian cancers, we reviewed publications studying PKC-alpha expression in these tumors. Since these investigations were mostly performed in cell lines, we supplemented this review with some preliminary findings from studies examining PKC-alpha expression in tumor tissue biopsies obtained from patients with breast and ovarian cancer. Based on the reviewed publications using representative cell lines and our preliminary findings on tumor tissue of patients with breast cancer, we infer that PKC-alpha levels may especially be increased in breast cancer patients with low or negative estrogen receptor (ER) levels. Thus, clinical studies determining efficacy of selective or specific inhibitors of PKC-alpha should include determination of ER status in order to help answer whether blocking PKC-alpha in patients with low or absent ER can result in clinical benefit.
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Affiliation(s)
- Michael Lahn
- Divison of Oncology Product Development, Lilly Research Laboratories, Eli Lilly, Indianapolis, IN 46285, USA.
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49
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Nicholson RI, Hutcheson IR, Knowlden JM, Jones HE, Harper ME, Jordan N, Hiscox SE, Barrow D, Gee JMW. Nonendocrine Pathways and Endocrine Resistance. Clin Cancer Res 2004; 10:346S-54S. [PMID: 14734490 DOI: 10.1158/1078-0432.ccr-031206] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
An increasing body of evidence demonstrates that growth factor networks are highly interactive with estrogen receptor signaling in the control of breast cancer growth. As such, tumor responses to antiestrogens are likely to be a composite of the estrogen receptor and growth factor-inhibitory activity of these agents, with alterations/aberrations in growth factor signaling providing a mechanism for the development of antiestrogen resistance. In this light, the current article focuses on illustrating the relationship between growth factor signaling and antiestrogen failure in our in-house tumor models of breast cancer and describing how we are now beginning to successfully target growth factor activity to improve the effects of antiestrogen drugs and to block aggressive disease progression.
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Affiliation(s)
- Robert I Nicholson
- Tenovus Centre for Cancer Research, Welsh School of Pharmacy, Cardiff, Wales, United Kingdom.
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Tonetti DA, Rubenstein R, DeLeon M, Zhao H, Pappas SG, Bentrem DJ, Chen B, Constantinou A, Craig Jordan V. Stable transfection of an estrogen receptor beta cDNA isoform into MDA-MB-231 breast cancer cells. J Steroid Biochem Mol Biol 2003; 87:47-55. [PMID: 14630090 DOI: 10.1016/j.jsbmb.2003.07.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We previously reported stable transfection of estrogen receptor alpha (ERalpha) into the ER-negative MDA-MB-231 cells (S30) as a tool to examine the mechanism of action of estrogen and antiestrogens [J. Natl. Cancer Inst. 84 (1992) 580]. To examine the mechanism of ERbeta action directly, we have similarly created ERbeta stable transfectants in MDA-MB-231 cells. MDA-MB-231 cells were stably transfected with ERbeta cDNA and clones were screened by estrogen response element (ERE)-luciferase assay and ERbeta mRNA expression was quantified by real-time RT-PCR. Three stable MDA-MB-231/ERbeta clones were compared with S30 cells with respect to their growth properties, ability to activate ERE- and activating protein-1 (AP-1) luciferase reporter constructs, and the ability to activate the endogenous ER-regulated transforming growth factor alpha (TGFalpha) gene. ERbeta6 and ERbeta27 clones express 300-400-fold and the ERbeta41 clone express 1600-fold higher ERbeta mRNA levels compared with untransfected MDA-MB-231 cells. Unlike S30 cells, 17beta-estradiol (E2) does not inhibit ERbeta41 cell growth. ERE-luciferase activity is induced six-fold by E2 whereas neither 4-hydroxytamoxifen (4-OHT) nor ICI 182, 780 activated an AP-1-luciferase reporter. TGFalpha mRNA is induced in response to E2, but not in response to 4-OHT. MDA-MB-231/ERbeta clones exhibit distinct characteristics from S30 cells including growth properties and the ability to induce TGFalpha gene expression. Furthermore, ERbeta, at least in the context of the MDA-MB-231 cellular milieu, does not enhance AP-1 activity in the presence of antiestrogens. In summary, the availability of both ERalpha and ERbeta stable breast cancer cell lines now allows us to compare and contrast the long-term consequences of individual signal transduction pathways.
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MESH Headings
- Breast Neoplasms/genetics
- Breast Neoplasms/metabolism
- Cell Division/genetics
- Cell Line, Tumor
- DNA, Complementary/genetics
- Estradiol/analogs & derivatives
- Estradiol/pharmacology
- Estrogen Receptor alpha
- Estrogen Receptor beta
- Gene Expression Regulation, Neoplastic/drug effects
- Gene Expression Regulation, Neoplastic/physiology
- Genes, Reporter/genetics
- Humans
- RNA, Messenger/analysis
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Response Elements/physiology
- Tamoxifen/analogs & derivatives
- Tamoxifen/pharmacology
- Transcription Factor AP-1/genetics
- Transcription Factor AP-1/metabolism
- Transcription, Genetic/drug effects
- Transcription, Genetic/physiology
- Transfection
- Transforming Growth Factor alpha/agonists
- Transforming Growth Factor alpha/metabolism
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Affiliation(s)
- Debra A Tonetti
- Department of Biopharmaceutical Sciences, College of Pharmacy M/C 865, University of Illinois at Chicago, 833 S. Wood Street, Chicago, IL 60612, USA.
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