1
|
Beumers L, Vlachavas EI, Borgoni S, Schwarzmüller L, Penso-Dolfin L, Michels BE, Sofyali E, Burmester S, Heiss D, Wilhelm H, Yarden Y, Helm D, Will R, Goncalves A, Wiemann S. Clonal heterogeneity in ER+ breast cancer reveals the proteasome and PKC as potential therapeutic targets. NPJ Breast Cancer 2023; 9:97. [PMID: 38042915 PMCID: PMC10693625 DOI: 10.1038/s41523-023-00604-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 11/17/2023] [Indexed: 12/04/2023] Open
Abstract
Intratumoral heterogeneity impacts the success or failure of anti-cancer therapies. Here, we investigated the evolution and mechanistic heterogeneity in clonal populations of cell models for estrogen receptor positive breast cancer. To this end, we established barcoded models of luminal breast cancer and rendered them resistant to commonly applied first line endocrine therapies. By isolating single clones from the resistant cell pools and characterizing replicates of individual clones we observed inter- (between cell lines) and intra-tumor (between different clones from the same cell line) heterogeneity. Molecular characterization at RNA and phospho-proteomic levels revealed private clonal activation of the unfolded protein response and respective sensitivity to inhibition of the proteasome, and potentially shared sensitivities for repression of protein kinase C. Our in vitro findings are consistent with tumor-heterogeneity that is observed in breast cancer patients thus highlighting the need to uncover heterogeneity at an individual patient level and to adjust therapies accordingly.
Collapse
Affiliation(s)
- Lukas Beumers
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany.
- Faculty of Biosciences, University of Heidelberg, Im Neuenheimer Feld 234, 69120, Heidelberg, Germany.
| | - Efstathios-Iason Vlachavas
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Simone Borgoni
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Luisa Schwarzmüller
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
- Faculty of Biosciences, University of Heidelberg, Im Neuenheimer Feld 234, 69120, Heidelberg, Germany
| | - Luca Penso-Dolfin
- Division of Somatic Evolution and Early Detection, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Birgitta E Michels
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Emre Sofyali
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Sara Burmester
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Daniela Heiss
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Heike Wilhelm
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Yosef Yarden
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Dominic Helm
- Proteomics Core Facility, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Rainer Will
- Cellular Tools Core Facility, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Angela Goncalves
- Division of Somatic Evolution and Early Detection, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Stefan Wiemann
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany.
- Faculty of Biosciences, University of Heidelberg, Im Neuenheimer Feld 234, 69120, Heidelberg, Germany.
| |
Collapse
|
2
|
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.
Collapse
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;
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Hamidi AA, Taghehchian N, Zangouei AS, Akhlaghipour I, Maharati A, Basirat Z, Moghbeli M. Molecular mechanisms of microRNA-216a during tumor progression. Cancer Cell Int 2023; 23:19. [PMID: 36740668 PMCID: PMC9899407 DOI: 10.1186/s12935-023-02865-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/02/2023] [Indexed: 02/07/2023] Open
Abstract
MicroRNAs (miRNAs) as the members of non-coding RNAs family are involved in post-transcriptional regulation by translational inhibiting or mRNA degradation. They have a critical role in regulation of cell proliferation and migration. MiRNAs aberrations have been reported in various cancers. Considering the importance of these factors in regulation of cellular processes and their high stability in body fluids, these factors can be suggested as suitable non-invasive markers for the cancer diagnosis. MiR-216a deregulation has been frequently reported in different cancers. Therefore, in the present review we discussed the molecular mechanisms of the miR-216a during tumor progression. It has been reported that miR-216a mainly functioned as a tumor suppressor through the regulation of signaling pathways and transcription factors. This review paves the way to suggest the miR-216a as a probable therapeutic and diagnostic target in cancer patients.
Collapse
Affiliation(s)
- Amir Abbas Hamidi
- grid.411583.a0000 0001 2198 6209Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Negin Taghehchian
- grid.411583.a0000 0001 2198 6209Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amir Sadra Zangouei
- grid.411583.a0000 0001 2198 6209Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Iman Akhlaghipour
- grid.411583.a0000 0001 2198 6209Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amirhosein Maharati
- grid.411583.a0000 0001 2198 6209Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Zahra Basirat
- grid.411583.a0000 0001 2198 6209Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Meysam Moghbeli
- grid.411583.a0000 0001 2198 6209Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran ,grid.411583.a0000 0001 2198 6209Department of Medical Genetics and Molecular Medicine, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| |
Collapse
|
5
|
Kawano T, Inokuchi J, Eto M, Murata M, Kang JH. Protein Kinase C (PKC) Isozymes as Diagnostic and Prognostic Biomarkers and Therapeutic Targets for Cancer. Cancers (Basel) 2022; 14:5425. [PMID: 36358843 PMCID: PMC9658272 DOI: 10.3390/cancers14215425] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/02/2022] [Accepted: 11/02/2022] [Indexed: 08/05/2023] Open
Abstract
Protein kinase C (PKC) is a large family of calcium- and phospholipid-dependent serine/threonine kinases that consists of at least 11 isozymes. Based on their structural characteristics and mode of activation, the PKC family is classified into three subfamilies: conventional or classic (cPKCs; α, βI, βII, and γ), novel or non-classic (nPKCs; δ, ε, η, and θ), and atypical (aPKCs; ζ, ι, and λ) (PKCλ is the mouse homolog of PKCι) PKC isozymes. PKC isozymes play important roles in proliferation, differentiation, survival, migration, invasion, apoptosis, and anticancer drug resistance in cancer cells. Several studies have shown a positive relationship between PKC isozymes and poor disease-free survival, poor survival following anticancer drug treatment, and increased recurrence. Furthermore, a higher level of PKC activation has been reported in cancer tissues compared to that in normal tissues. These data suggest that PKC isozymes represent potential diagnostic and prognostic biomarkers and therapeutic targets for cancer. This review summarizes the current knowledge and discusses the potential of PKC isozymes as biomarkers in the diagnosis, prognosis, and treatment of cancers.
Collapse
Affiliation(s)
- Takahito Kawano
- Center for Advanced Medical Innovation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Junichi Inokuchi
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Masatoshi Eto
- Center for Advanced Medical Innovation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Masaharu Murata
- Center for Advanced Medical Innovation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Jeong-Hun Kang
- Division of Biopharmaceutics and Pharmacokinetics, National Cerebral and Cardiovascular Center Research Institute, 6-1 Shinmachi, Kishibe, Suita, Osaka 564-8565, Japan
| |
Collapse
|
6
|
Biswas S, Mahapatra E, Das S, Roy M, Mukherjee S. PEITC: A resounding molecule averts metastasis in breast cancer cells in vitro by targeting serine/threonine kinase interplay. Heliyon 2022; 8:e11656. [DOI: 10.1016/j.heliyon.2022.e11656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 01/03/2022] [Accepted: 11/07/2022] [Indexed: 11/16/2022] Open
|
7
|
Filippone MG, Freddi S, Zecchini S, Restelli S, Colaluca IN, Bertalot G, Pece S, Tosoni D, Di Fiore PP. Aberrant phosphorylation inactivates Numb in breast cancer causing expansion of the stem cell pool. J Cell Biol 2022; 221:213525. [PMID: 36200956 PMCID: PMC9545709 DOI: 10.1083/jcb.202112001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 07/19/2022] [Accepted: 09/14/2022] [Indexed: 12/13/2022] Open
Abstract
Asymmetric cell division is a key tumor suppressor mechanism that prevents the uncontrolled expansion of the stem cell (SC) compartment by generating daughter cells with alternative fates: one retains SC identity and enters quiescence and the other becomes a rapidly proliferating and differentiating progenitor. A critical player in this process is Numb, which partitions asymmetrically at SC mitosis and inflicts different proliferative and differentiative fates in the two daughters. Here, we show that asymmetric Numb partitioning per se is insufficient for the proper control of mammary SC dynamics, with differential phosphorylation and functional inactivation of Numb in the two progeny also required. The asymmetric phosphorylation/inactivation of Numb in the progenitor is mediated by the atypical PKCζ isoform. This mechanism is subverted in breast cancer via aberrant activation of PKCs that phosphorylate Numb in both progenies, leading to symmetric division and expansion of the cancer SC compartment, associated with aggressive disease. Thus, Numb phosphorylation represents a target for breast cancer therapy.
Collapse
Affiliation(s)
- Maria Grazia Filippone
- IEO-IRCCS, Istituto Europeo di Oncologia-Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy
| | - Stefano Freddi
- IEO-IRCCS, Istituto Europeo di Oncologia-Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy
| | - Silvia Zecchini
- IEO-IRCCS, Istituto Europeo di Oncologia-Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy
| | - Silvia Restelli
- IEO-IRCCS, Istituto Europeo di Oncologia-Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy
| | - Ivan Nicola Colaluca
- IEO-IRCCS, Istituto Europeo di Oncologia-Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy
| | - Giovanni Bertalot
- IEO-IRCCS, Istituto Europeo di Oncologia-Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy
| | - Salvatore Pece
- IEO-IRCCS, Istituto Europeo di Oncologia-Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy,Dipartimento di Oncologia e Emato-Oncologia, Università degli Studi di Milano, Milan, Italy
| | - Daniela Tosoni
- IEO-IRCCS, Istituto Europeo di Oncologia-Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy
| | - Pier Paolo Di Fiore
- IEO-IRCCS, Istituto Europeo di Oncologia-Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy,Dipartimento di Oncologia e Emato-Oncologia, Università degli Studi di Milano, Milan, Italy,Correspondence to Pier Paolo Di Fiore:
| |
Collapse
|
8
|
Black JD, Affandi T, Black AR, Reyland ME. PKCα and PKCδ: Friends and Rivals. J Biol Chem 2022; 298:102194. [PMID: 35760100 PMCID: PMC9352922 DOI: 10.1016/j.jbc.2022.102194] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/13/2022] [Accepted: 06/21/2022] [Indexed: 01/06/2023] Open
Abstract
PKC comprises a large family of serine/threonine kinases that share a requirement for allosteric activation by lipids. While PKC isoforms have significant homology, functional divergence is evident among subfamilies and between individual PKC isoforms within a subfamily. Here, we highlight these differences by comparing the regulation and function of representative PKC isoforms from the conventional (PKCα) and novel (PKCδ) subfamilies. We discuss how unique structural features of PKCα and PKCδ underlie differences in activation and highlight the similar, divergent, and even opposing biological functions of these kinases. We also consider how PKCα and PKCδ can contribute to pathophysiological conditions and discuss challenges to targeting these kinases therapeutically.
Collapse
Affiliation(s)
- Jennifer D Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE.
| | - Trisiani Affandi
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus
| | - Adrian R Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE
| | - Mary E Reyland
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus.
| |
Collapse
|
9
|
TRIM47 activates NF-κB signaling via PKC-ε/PKD3 stabilization and contributes to endocrine therapy resistance in breast cancer. Proc Natl Acad Sci U S A 2021; 118:2100784118. [PMID: 34433666 DOI: 10.1073/pnas.2100784118] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Increasing attention has been paid to roles of tripartite motif-containing (TRIM) family proteins in cancer biology, often functioning as E3 ubiquitin ligases. In the present study, we focus on a contribution of TRIM47 to breast cancer biology, particularly to endocrine therapy resistance, which is a major clinical problem in breast cancer treatment. We performed immunohistochemical analysis of TRIM47 protein expression in 116 clinical samples of breast cancer patients with postoperative endocrine therapy using tamoxifen. Our clinicopathological study showed that higher immunoreactivity scores of TRIM47 were significantly associated with higher relapse rate of breast cancer patients (P = 0.012). As functional analyses, we manipulated TRIM47 expression in estrogen receptor-positive breast cancer cells MCF-7 and its 4-hydroxytamoxifen (OHT)-resistant derivative OHTR, which was established in a long-term culture with OHT. TRIM47 promoted both MCF-7 and OHTR cell proliferation. MCF-7 cells acquired tamoxifen resistance by overexpressing exogenous TRIM47. We found that TRIM47 enhances nuclear factor kappa-B (NF-κB) signaling, which further up-regulates TRIM47. We showed that protein kinase C epsilon (PKC-ε) and protein kinase D3 (PKD3), known as NF-κB-activating protein kinases, are directly associated with TRIM47 and stabilized in the presence of TRIM47. As an underlying mechanism, we showed TRIM47-dependent lysine 27-linked polyubiquitination of PKC-ε. These results indicate that TRIM47 facilitates breast cancer proliferation and endocrine therapy resistance by forming a ternary complex with PKC-ε and PKD3. TRIM47 and its associated kinases can be a potential diagnostic and therapeutic target for breast cancer refractory to endocrine therapy.
Collapse
|
10
|
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.
Collapse
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.
| |
Collapse
|
11
|
Phase 1 study of TTC-352 in patients with metastatic breast cancer progressing on endocrine and CDK4/6 inhibitor therapy. Breast Cancer Res Treat 2020; 183:617-627. [PMID: 32696319 DOI: 10.1007/s10549-020-05787-z] [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: 05/17/2020] [Accepted: 07/02/2020] [Indexed: 01/04/2023]
Abstract
PURPOSE TTC-352 is a selective human estrogen receptor (ER) partial agonist developed for treatment of hormone-refractory ER + breast cancer. METHODS This was an accelerated dose escalation study with the primary endpoint of maximum tolerated dose that evaluated five dose levels of TTC-352 in breast cancer progressing after at least two lines of hormonal therapy including one in combination with a CDK4/6 inhibitor. The secondary objectives were to determine treatment tolerability, pharmacokinetics of TTC-352, best response, progression-free survival (PFS), and PKCα expression in tumors. RESULTS The study enrolled 15 patients. No dose-limiting toxicity was observed. Patients experienced the following grade 3 toxicities: asymptomatic pulmonary embolism, diarrhea, aspartate transaminase elevation, and myalgia, and one grade 4 toxicity of gamma glutamyltransferase elevation. Pharmacokinetic half-life was 7.6-14.3 h. The intra- and inter-individual variability for AUC0-∞ hampered assessment of the relationship between dose and AUC0-∞. Median PFS was 58 days (95% CI = 28,112). Higher PKCα expression in tumor stroma was associated with a trend toward longer PFS. CONCLUSIONS TTC-352 demonstrates safety and early clinical evidence of antitumor activity against heavily pretreated hormone-refractory breast cancer. Based upon TTC-352 plasma concentrations and tolerability, the 180 mg twice a day is recommended for further testing. (ClinicalTrials.gov Identifier: NCT03201913).
Collapse
|
12
|
Cui Y, Wang J, Liu S, Qu D, Jin H, Zhu L, Yang J, Zhang J, Li Q, Zhang Y, Yao Y. miR‐216a promotes breast cancer cell apoptosis by targeting
PKC
α. Fundam Clin Pharmacol 2019; 33:397-404. [PMID: 31119784 DOI: 10.1111/fcp.12481] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 04/22/2019] [Accepted: 05/10/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Ying Cui
- Department of Radiation Oncology Harbin Medical University Cancer Hospital Heilongjiang 150081 China
| | - Jinghao Wang
- Department of Pharmacy the First Affiliated Hospital Jinan University Guangzhou 510630 China
| | - Shanshan Liu
- Department of Radiation Oncology Harbin Medical University Cancer Hospital Heilongjiang 150081 China
| | - Di Qu
- Department of Medical Oncology the Second Affiliated Hospital of Harbin Medical University Heilongjiang 150086 China
| | - Hong Jin
- Department of Gynecology Harbin Medical University Cancer Hospital Heilongjiang 150081 China
| | - Lin Zhu
- Department of Radiation Oncology Harbin Medical University Cancer Hospital Heilongjiang 150081 China
| | - Jiani Yang
- Department of Medical Oncology Harbin Medical University Cancer Hospital Heilongjiang 150081China
| | - Jingchun Zhang
- Department of Medical Oncology Harbin Medical University Cancer Hospital Heilongjiang 150081China
| | - Qingwei Li
- Department of Medical Oncology Harbin Medical University Cancer Hospital Heilongjiang 150081China
| | - Yanqiao Zhang
- Department of Medical Oncology Harbin Medical University Cancer Hospital Heilongjiang 150081China
| | - Yuanfei Yao
- Department of Medical Oncology Harbin Medical University Cancer Hospital Heilongjiang 150081China
| |
Collapse
|
13
|
Claudin 1 Is Highly Upregulated by PKC in MCF7 Human Breast Cancer Cells and Correlates Positively with PKCε in Patient Biopsies. Transl Oncol 2019; 12:561-575. [PMID: 30658316 PMCID: PMC6349319 DOI: 10.1016/j.tranon.2018.12.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 12/20/2018] [Accepted: 12/23/2018] [Indexed: 01/04/2023] Open
Abstract
Recent studies provide compelling evidence to suggest that the tight junction protein claudin 1, aberrantly expressed in several cancer types, plays an important role in cancer progression. Dysregulation of claudin 1 has been shown to induce epithelial mesenchymal transition (EMT). Furthermore, activation of the ERK signaling pathway by protein kinase C (PKC) was shown to be necessary for EMT induction. Whether PKC is involved in regulating breast cancer progression has not been addressed. The PKC activator 12-O-tetradecanoylphorbol 13-acetate (TPA) was used to investigate the effect of PKC activity on claudin 1 transcription and protein levels, subcellular distribution, and alterations in EMT markers in human breast cancer (HBC) cell lines. As well, tissue microarray analysis (TMA) of a large cohort of invasive HBC biopsies was conducted to investigate correlations between claudin 1 and PKC isomers. TPA upregulated claudin 1 levels in all HBC cell lines analyzed. In particular, a high induction of claudin 1 protein was observed in the MCF7 cell line. TPA treatment also led to an accumulation of claudin 1 in the cytoplasm. Additionally, we demonstrated that the upregulation of claudin 1 was through the ERK signaling pathway. In patient biopsies, we identified a significant positive correlation between claudin 1, PKCα, and PKCε in ER+ tumors. A similar correlation between claudin 1 and PKCε was identified in ER- tumors, and high PKCε was associated with shorter disease-free survival. Collectively, these studies demonstrate that claudin 1 and the ERK signaling pathway are important players in HBC progression.
Collapse
|
14
|
Sun S, Wu Q, Song J, Sun S. Protein kinase C δ-dependent regulation of Ubiquitin-proteasome system function in breast cancer. Cancer Biomark 2018; 21:1-9. [PMID: 29036789 DOI: 10.3233/cbm-170451] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Besides the crucial role of hyperinsulinemia in the development of breast cancer with Type 2 diabetes mellitus (T2DM), it has been shown that hyperglycemia could contribute to promote cancer progression. A remarkable association within hyperglycemia, PKCδ and Ubiquitin-proteasome system (UPS) has been reported, suggesting that PKCδ may mediate high glucose-induced UPS activation in breast cancer cells. Although the independent effects of PKCδ or UPS on breast cancer and T2DM are increasingly supported by experimental evidence, the complex interactional link between PKCδ and UPS is still unclear. Hence, we focus on the relationship between PKCδ and UPS in breast cancer with T2DM. We hypothesize that PKCδ may have the function to regulate the activity of UPS. Further, we speculate that PKCδ combine with proteasome α2 promoter, that indicate PKCδ regulate the function of UPS by change the composition of proteasome. Therefore, we surmise that PKCδ mediated high glucose-induced UPS activation in breast cancer cells, and specific PKCδ inhibitor rottlerin significantly suppressed elevated glucose induced the activity of UPS. We hope that our paper will stimulate further studies the relationship between PKCδ and UPS, and a new targeted therapy and early medical intervention for PKCδ could be a useful option for breast cancer cases complicated with T2DM or hyperglycemia.
Collapse
Affiliation(s)
- Si Sun
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Qi Wu
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Junlong Song
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Shengrong Sun
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| |
Collapse
|
15
|
Mao J, Hu X, Pang P, Zhou B, Zhang Y, Li D, Shan H. Establishment of a CRISPR/Cas9-Mediated Cysltr1
Knockout Mouse Model and iTRAQ-Based Proteomic Analysis. Proteomics Clin Appl 2018; 12:e1700087. [PMID: 29377627 DOI: 10.1002/prca.201700087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 01/07/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Junjie Mao
- Department of Interventional Medicine The Fifth Affiliated Hospital; Sun Yat-sen University; Zhuhai P.R. China
- Department of Interventional Medicine The Third Affiliated Hospital; Sun Yat-sen University; Guangzhou P.R. China
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital; Sun Yat-sen University; Zhuhai P.R. China
- Institute of Interventional Radiology; Sun Yat-sen University; Zhuhai P.R. China
| | - Xiaojun Hu
- Department of Interventional Medicine The Fifth Affiliated Hospital; Sun Yat-sen University; Zhuhai P.R. China
- Institute of Interventional Radiology; Sun Yat-sen University; Zhuhai P.R. China
| | - Pengfei Pang
- Department of Interventional Medicine The Fifth Affiliated Hospital; Sun Yat-sen University; Zhuhai P.R. China
- Institute of Interventional Radiology; Sun Yat-sen University; Zhuhai P.R. China
| | - Bin Zhou
- Department of Interventional Medicine The Fifth Affiliated Hospital; Sun Yat-sen University; Zhuhai P.R. China
- Institute of Interventional Radiology; Sun Yat-sen University; Zhuhai P.R. China
| | - Yaqin Zhang
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital; Sun Yat-sen University; Zhuhai P.R. China
| | - Dan Li
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital; Sun Yat-sen University; Zhuhai P.R. China
- Institute of Interventional Radiology; Sun Yat-sen University; Zhuhai P.R. China
| | - Hong Shan
- Department of Interventional Medicine The Fifth Affiliated Hospital; Sun Yat-sen University; Zhuhai P.R. China
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital; Sun Yat-sen University; Zhuhai P.R. China
- Institute of Interventional Radiology; Sun Yat-sen University; Zhuhai P.R. China
| |
Collapse
|
16
|
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.
Collapse
|
17
|
Wu CH, Yang MY, Lee YJ, Wang CJ. Nelumbo nucifera leaf polyphenol extract inhibits breast cancer cells metastasis in vitro and in vivo through PKCα targeting. J Funct Foods 2017. [DOI: 10.1016/j.jff.2017.08.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
18
|
Identification and characterisation of lamprey protein kinase C delta-like gene. Sci Rep 2017; 7:12214. [PMID: 28939820 PMCID: PMC5610172 DOI: 10.1038/s41598-017-12526-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 08/15/2017] [Indexed: 01/13/2023] Open
Abstract
Protein kinase C-δ (PKC-δ), a member of the lipid-regulated serine/threonine PKC family, has been implicated in a wide range of important cellular processes, such as cell growth, differentiation, and apoptosis. Lampreys belong to the most primitive class of vertebrates, and there is little information on PKC-δ in these animals. In this study, a PKC-δ-like cDNA sequence and deduced PKC-δ-like amino acid sequence were identified in the Japanese lamprey (Lampetra japonica). The PKC-δ-like gene shared approximately 60% sequence identity with its homologs in jawed vertebrates. The anti-PKC-δ-like polyclonal antibodies were well prepared, and experiments showed that PKC-δ-like was primarily distributed in the supraneural body of the lamprey. Both mRNA and protein levels of PKC-δ-like in supraneural body cells were increased after incubation with cis-diaminedichloroplatinum (CDDP). Moreover, PKC-δ-like protein induced the apoptosis of HEK-293T cells. In addition, the activation of PKC-δ-like resulted in apoptosis. Conversely, the inhibition of PKC-δ-like activity disrupted the CDDP-mediated induction of cellular apoptosis. These results indicate that PKC-δ-like identified in lampreys might play an important role in apoptosis in jawless vertebrates.
Collapse
|
19
|
Hwang E, Yoo KC, Kang SG, Kim RK, Cui YH, Lee HJ, Kim MJ, Lee JS, Kim IG, Suh Y, Lee SJ. PKCδ activated by c-MET enhances infiltration of human glioblastoma cells through NOTCH2 signaling. Oncotarget 2016; 7:4890-902. [PMID: 26700818 PMCID: PMC4826251 DOI: 10.18632/oncotarget.6640] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 12/05/2015] [Indexed: 11/25/2022] Open
Abstract
Poor prognosis of glioblastoma (GBM) is attributable to the propensity of tumor cells to infiltrate into the brain parenchyma. Protein kinase C (PKC) isozymes are highly expressed or aberrantly activated in GBM. However, how this signaling node translates to GBM cell invasiveness remains unknown. Here, we report that among PKC isoforms, PKCδ is strongly associated with infiltration of GBM cells. Notably, PKCδ enhanced Tyr418 phosphorylation of the non-receptor tyrosine kinase SRC, which in turn activated STAT3 and subsequent NOTCH2 signaling, ultimately leading to GBM cell invasiveness. Furthermore, we showed that PKCδ was aberrantly activated in GBM cells by c-MET, a receptor tyrosine kinase hyperactivated in GBM. In agreement, inhibition either component in the c-MET/PKCδ/SRC/STAT3 signaling axis effectively blocked the NOTCH2 signaling and invasiveness of GBM cells. Taken together, our findings shed a light on the signaling mechanisms behind the constitutive activation of PKCδ signaling in GBM.
Collapse
Affiliation(s)
- Eunji Hwang
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Korea
| | - Ki-Chun Yoo
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Korea
| | - Seok-Gu Kang
- Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seodaemun-gu, Korea
| | - Rae-Kwon Kim
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Korea
| | - Yan-Hong Cui
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Korea
| | - Hae-June Lee
- Division of Radiation Effect, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Min-Jung Kim
- Laboratory of Radiation Exposure & Therapeutics, National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jae-Seong Lee
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Seoul, Korea
| | - In-Gyu Kim
- Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon, Korea
| | - Yongjoon Suh
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Korea
| | - Su-Jae Lee
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Korea
| |
Collapse
|
20
|
Yue CH, Liu LC, Kao ES, Lin H, Hsu LS, Hsu CW, Lin YY, Lin YS, Liu JY, Lee CJ. Protein kinase C α is involved in the regulation of AXL receptor tyrosine kinase expression in triple-negative breast cancer cells. Mol Med Rep 2016; 14:1636-42. [PMID: 27357025 DOI: 10.3892/mmr.2016.5424] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 03/22/2016] [Indexed: 11/06/2022] Open
Abstract
AXL receptor tyrosine kinase is overexpressed in triple-negative breast cancer (TNBC), and has a function in cancer progression and metastases. However, the mechanism underlying AXL gene regulation in TNBC remains unknown. In this study, the involvement of protein kinase C α (PKCα) in the expression of AXL was investigated in human TNBC cells. The microarray data from other studies showed that PKCα is significantly correlated with AXL expression in TNBC cell lines. Tissue array analysis also confirmed their correlation in TNBC. The PKCα inhibitor Go6976 was used to treat MDA‑MB‑231 and Hs578T TNBC cells, which resulted in decreased expression of AXL and epithelia-mesenchymal transition-related gene vimentin, and decreased cell proliferation. An MZF‑1 acidic domain fragment (MZF-1 peptide), which was designed to downregulate PKCα expression, was transfected into the cells and resulted in inhibition of AXL expression. This effect was reversed by co‑treatment with the constitutive form of PKCα. Moreover, the downregulation of PKCα was also confirmed by treatment with TAT‑fused MZF‑1 peptide. Thus, the current study proposes that AXL may be correlated with PKCα‑dependent TNBC cells, and could be modulated by MZF‑1 peptides.
Collapse
Affiliation(s)
- Chia-Herng Yue
- Department of Surgery, Tungs' Taichung Metroharbor Hospital, Taichung 435, Taiwan, R.O.C
| | - Liang-Chih Liu
- Department of Surgery, China Medical University Hospital, Changhua 404, Taiwan, R.O.C
| | - Erl-Shyh Kao
- Department of Beauty Science and Graduate Institute of Beauty Science Technology, Chienkuo Technology University, Taichung 500, Taiwan, R.O.C
| | - Ho Lin
- Department of Life Science, National Chung Hsing University, Taichung 40402, Taiwan, R.O.C
| | - Li-Sung Hsu
- Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 404, Taiwan, R.O.C
| | - Chih-Wei Hsu
- Department of Surgery, Tungs' Taichung Metroharbor Hospital, Taichung 435, Taiwan, R.O.C
| | - Yu-Yu Lin
- Graduate Institute of Cancer Biology, College of Medicine, China Medical University, Taichung 404, Taiwan, R.O.C
| | - Yi-Syuan Lin
- Department of Biotechnology, Asia University, Taichung 413, Taiwan, R.O.C
| | - Jer-Yuh Liu
- Graduate Institute of Cancer Biology, College of Medicine, China Medical University, Taichung 404, Taiwan, R.O.C
| | - Chia-Jen Lee
- Center for Molecular Medicine, China Medical University Hospital, Taichung 404, Taiwan, R.O.C
| |
Collapse
|
21
|
Yang J, Zhang J. Influence of protein kinase C (PKC) on the prognosis of diabetic nephropathy patients. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:14925-14931. [PMID: 26823823 PMCID: PMC4713609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/21/2015] [Indexed: 06/05/2023]
Abstract
AIMS To investigate the association between protein kinase C (PKC) and the prognosis of patients with diabetic nephropathy (DN). METHODS 92 patients with DN who had received treatments with angiotensin converting enzyme inhibitor (ACEI) or angiotensin-receptor blockade (ARB) were collected. The clinicopathologic characteristics were recorded and a 4-year follow-up with the final result of impaired renal functions (eGFR < 40 mL/min) was conducted. The expression of PKC was detected by immunohistochemical assay. Kaplan-Meier and Cox regression analysis were performed to estimate the effects of PKC on DN prognosis. RESULTS According to immunohistochemical analysis, there were 54 cases with positive expression of PKC (positive rate 58.7%). Meanwhile, during the follow-up, the urine protein, mean serum creatinine and eGFR in patients with positive PKC were all higher than those in negative expression group (P < 0.05). The expression of PKC was influenced by age (P < 0.001), course of disease (P < 0.001), blood pressure (P = 0.002), blood glucose (P < 0.001), HbA1c (P = 0.002), renal functions of patients before (P = 0.011) and after (P = 0.041) the biopsy. Besides, the Kaplan-Meier curve revealed that patients with positive PKC expression had shorter survival time than those with negative PKC expression (P < 0.001). Cox regression analysis indicated that HbA1c (P = 0.009), renal functions of patients after the biopsy (P = 0.002) and PKC (P = 0.028) were important factors in the prognosis of DN and they might be independent prognostic markers. CONCLUSION The expression of PKC is relatively higher in DN patients than in healthy controls. And PKC may be a valuable prognostic marker for patients with DN.
Collapse
Affiliation(s)
- Jie Yang
- Second Department of Endocrinology, Tai An Central Hospital Shandong Province, China
| | - Jian Zhang
- Second Department of Endocrinology, Tai An Central Hospital Shandong Province, China
| |
Collapse
|
22
|
Tamoxifen resistance: From cell culture experiments towards novel biomarkers. Pathol Res Pract 2015; 211:189-97. [DOI: 10.1016/j.prp.2015.01.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 01/12/2015] [Accepted: 01/13/2015] [Indexed: 12/21/2022]
|
23
|
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.
Collapse
Affiliation(s)
- V Craig Jordan
- Departments of Breast Medical Oncology and Molecular and Cellular OncologyMD Anderson Cancer Center, Houston, Texas 77030, USA
| |
Collapse
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
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.
Collapse
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.
| |
Collapse
|
26
|
Elias D, Vever H, Lænkholm AV, Gjerstorff MF, Yde CW, Lykkesfeldt AE, Ditzel HJ. Gene expression profiling identifies FYN as an important molecule in tamoxifen resistance and a predictor of early recurrence in patients treated with endocrine therapy. Oncogene 2014; 34:1919-27. [PMID: 24882577 DOI: 10.1038/onc.2014.138] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 03/13/2014] [Accepted: 03/26/2014] [Indexed: 01/02/2023]
Abstract
To elucidate the molecular mechanisms of tamoxifen resistance in breast cancer, we performed gene array analyses and identified 366 genes with altered expression in four unique tamoxifen-resistant (TamR) cell lines vs the parental tamoxifen-sensitive MCF-7/S0.5 cell line. Most of these genes were functionally linked to cell proliferation, death and control of gene expression, and include FYN, PRKCA, ITPR1, DPYD, DACH1, LYN, GBP1 and PRLR. Treatment with FYN-specific small interfering RNA or a SRC family kinase inhibitor reduced cell growth of TamR cell lines while exerting no significant effect on MCF-7/S0.5 cells. Moreover, overexpression of FYN in parental tamoxifen-sensitive MCF-7/S0.5 cells resulted in reduced sensitivity to tamoxifen treatment, whereas knockdown of FYN in the FYN-overexpressing MCF-7/S0.5 cells restored sensitivity to tamoxifen, demonstrating growth- and survival-promoting function of FYN in MCF-7 cells. FYN knockdown in TamR cells led to reduced phosphorylation of 14-3-3 and Cdc25A, suggesting that FYN, by activation of important cell cycle-associated proteins, may overcome the anti-proliferative effects of tamoxifen. Evaluation of the subcellular localization of FYN in primary breast tumors from two cohorts of endocrine-treated ER+ breast cancer patients, one with advanced disease (N=47) and the other with early disease (N=76), showed that in the former, plasma membrane-associated FYN expression strongly correlated with longer progression-free survival (P<0.0002). Similarly, in early breast cancer patients, membrane-associated expression of FYN in the primary breast tumor was significantly associated with increased metastasis-free (P<0.04) and overall (P<0.004) survival independent of tumor size, grade or lymph node status. Our results indicate that FYN has an important role in tamoxifen resistance, and its subcellular localization in breast tumor cells may be an important novel biomarker of response to endocrine therapy in breast cancer.
Collapse
Affiliation(s)
- D Elias
- Department of Cancer and Inflammation Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - H Vever
- Department of Cancer and Inflammation Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - A-V Lænkholm
- Department of Pathology, Slagelse Hospital, Slagelse, Denmark
| | - M F Gjerstorff
- Department of Cancer and Inflammation Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - C W Yde
- Breast Cancer Group, Cell Death and Metabolism, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - A E Lykkesfeldt
- Breast Cancer Group, Cell Death and Metabolism, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - H J Ditzel
- 1] Department of Cancer and Inflammation Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark [2] Department of Oncology, Odense University Hospital, Odense, Denmark
| |
Collapse
|
27
|
Abstract
Protein kinase C (PKC) is a family of phospholipid-dependent serine/threonine kinases, which can be further classified into three PKC isozymes subfamilies: conventional or classic, novel or nonclassic, and atypical. PKC isozymes are known to be involved in cell proliferation, survival, invasion, migration, apoptosis, angiogenesis, and drug resistance. Because of their key roles in cell signaling, PKC isozymes also have the potential to be promising therapeutic targets for several diseases, such as cardiovascular diseases, immune and inflammatory diseases, neurological diseases, metabolic disorders, and multiple types of cancer. This review primarily focuses on the activation, mechanism, and function of PKC isozymes during cancer development and progression.
Collapse
|
28
|
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.
Collapse
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
| |
Collapse
|
29
|
Zhang F, Wang M, Michael T, Drabier R. Novel alternative splicing isoform biomarkers identification from high-throughput plasma proteomics profiling of breast cancer. BMC SYSTEMS BIOLOGY 2013; 7 Suppl 5:S8. [PMID: 24565027 PMCID: PMC4028860 DOI: 10.1186/1752-0509-7-s5-s8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND In the biopharmaceutical industry, biomarkers define molecular taxonomies of patients and diseases and serve as surrogate endpoints in early-phase drug trials. Molecular biomarkers can be much more sensitive than traditional lab tests. Discriminating disease biomarkers by traditional method such as DNA microarray has proved challenging. Alternative splicing isoform represents a new class of diagnostic biomarkers. Recent scientific evidence is demonstrating that the differentiation and quantification of individual alternative splicing isoforms could improve insights into disease diagnosis and management. Identifying and characterizing alternative splicing isoforms are essential to the study of molecular mechanisms and early detection of complex diseases such as breast cancer. However, there are limitations with traditional methods used for alternative splicing isoform determination such as transcriptome-level, low level of coverage and poor focus on alternative splicing. RESULTS Therefore, we presented a peptidomics approach to searching novel alternative splicing isoforms in clinical proteomics. Our results showed that the approach has significant potential in enabling discovery of new types of high-quality alternative splicing isoform biomarkers. CONCLUSIONS We developed a peptidomics approach for the proteomics community to analyze, identify, and characterize alternative splicing isoforms from MS-based proteomics experiments with more coverage and exclusive focus on alternative splicing. The approach can help generate novel hypotheses on molecular risk factors and molecular mechanisms of cancer in early stage, leading to identification of potentially highly specific alternative splicing isoform biomarkers for early detection of cancer.
Collapse
|
30
|
Browne BC, Hochgräfe F, Wu J, Millar EKA, Barraclough J, Stone A, McCloy RA, Lee CS, Roberts C, Ali NA, Boulghourjian A, Schmich F, Linding R, Farrow L, Gee JMW, Nicholson RI, O'Toole SA, Sutherland RL, Musgrove EA, Butt AJ, Daly RJ. Global characterization of signalling networks associated with tamoxifen resistance in breast cancer. FEBS J 2013; 280:5237-57. [PMID: 23876235 DOI: 10.1111/febs.12441] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/27/2013] [Accepted: 07/17/2013] [Indexed: 12/30/2022]
Abstract
Acquired resistance to the anti-estrogen tamoxifen remains a significant challenge in breast cancer management. In this study, we used an integrative approach to characterize global protein expression and tyrosine phosphorylation events in tamoxifen-resistant MCF7 breast cancer cells (TamR) compared with parental controls. Quantitative mass spectrometry and computational approaches were combined to identify perturbed signalling networks, and candidate regulatory proteins were functionally interrogated by siRNA-mediated knockdown. Network analysis revealed that cellular metabolism was perturbed in TamR cells, together with pathways enriched for proteins associated with growth factor, cell-cell and cell matrix-initiated signalling. Consistent with known roles for Ras/MAPK and PI3-kinase signalling in tamoxifen resistance, tyrosine-phosphorylated MAPK1, SHC1 and PIK3R2 were elevated in TamR cells. Phosphorylation of the tyrosine kinase Yes and expression of the actin-binding protein myristoylated alanine-rich C-kinase substrate (MARCKS) were increased two- and eightfold in TamR cells respectively, and these proteins were selected for further analysis. Knockdown of either protein in TamR cells had no effect on anti-estrogen sensitivity, but significantly decreased cell motility. MARCKS expression was significantly higher in breast cancer cell lines than normal mammary epithelial cells and in ER-negative versus ER-positive breast cancer cell lines. In primary breast cancers, cytoplasmic MARCKS staining was significantly higher in basal-like and HER2 cancers than in luminal cancers, and was independently predictive of poor survival in multivariate analyses of the whole cohort (P < 0.0001) and in ER-positive patients (P = 0.0005). These findings provide network-level insights into the molecular alterations associated with the tamoxifen-resistant phenotype, and identify MARCKS as a potential biomarker of therapeutic responsiveness that may assist in stratification of patients for optimal therapy.
Collapse
Affiliation(s)
- Brigid C Browne
- Cancer Research Program, The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
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.
Collapse
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
| |
Collapse
|
32
|
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.
Collapse
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
| | | | | | | | | |
Collapse
|
33
|
Xu Y, Zou ST, Zhu R, Li W, Gu CW, Wei SH, Xie JM, Wu HR. Inhibition of proliferation of estrogen receptor‑positive MCF‑7 human breast cancer cells by tamoxifen through c‑Jun transcription factors. Mol Med Rep 2013; 7:1283-7. [PMID: 23404426 DOI: 10.3892/mmr.2013.1306] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 01/21/2013] [Indexed: 11/06/2022] Open
Abstract
Activator of protein 1 (AP-1) is a heterodimeric transcription factor composed of various members of the Jun and Fos families and binds to DNA at specific AP-1 binding sites. AP-1 transcriptional activity is increased by phosphorylation at serine residues in the c‑Jun component of AP-1. In the present study, the proliferation of MCF-7 breast cancer cells was found to be suppressed by tamoxifen (TAM)-activated c-Jun through the protein kinase C (PKC) pathway. The molecular mechanism by which c‑Jun activation induces antiproliferative signals in estrogen receptor (ER)-positive MCF-7 human breast cancer cells remains unknown. TAM inhibited the proliferation of ER-positive MCF-7 human breast cancer cells and ER-negative MDA-MB-435 human breast cancer cells and 48 h incubation with 10 µM TAM led to inhibition of 80% of proliferation. In addition, no significant difference in c-Jun mRNA and protein levels was detected in MCF-7 and MDA-MB-435 cells stimulated by TAM for 48 h. TAM treatment of MCF-7 cells activated the transcriptional activity of AP-1, which responds specifically to phorbol ester. To determine the role of c-Jun in the antiproliferation of MCF-7 cells stimulated by TAM, the inhibition rates of MCF‑7 cells were correlated with c‑Jun expression and stimulation of TAM. Results showed that the inhibition rate of TAM-stimulated MCF-7 cells was positively regulated by overexpression of c-Jun and negatively regulated by underexpression of c-Jun. Overall, these results indicate that the TAM-stimulated antiproliferation of MCF-7 cells is positively regulated by c-Jun through activation of the PKC pathway.
Collapse
Affiliation(s)
- Yan Xu
- Department of General Surgery, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R China
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Koese M, Rentero C, Kota BP, Hoque M, Cairns R, Wood P, Vilà de Muga S, Reverter M, Alvarez-Guaita A, Monastyrskaya K, Hughes WE, Swarbrick A, Tebar F, Daly RJ, Enrich C, Grewal T. Annexin A6 is a scaffold for PKCα to promote EGFR inactivation. Oncogene 2012; 32:2858-72. [PMID: 22797061 DOI: 10.1038/onc.2012.303] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Protein kinase Cα (PKCα) can phosphorylate the epidermal growth factor receptor (EGFR) at threonine 654 (T654) to inhibit EGFR tyrosine phosphorylation (pY-EGFR) and the associated activation of downstream effectors. However, upregulation of PKCα in a large variety of cancers is not associated with EGFR inactivation, and factors determining the potential of PKCα to downregulate EGFR are yet unknown. Here, we show that ectopic expression of annexin A6 (AnxA6), a member of the Ca(2+) and phospholipid-binding annexins, strongly reduces pY-EGFR levels while augmenting EGFR T654 phosphorylation in EGFR overexpressing A431, head and neck and breast cancer cell lines. Reduced EGFR activation in AnxA6 expressing A431 cells is associated with reduced EGFR internalization and degradation. RNA interference (RNAi)-mediated PKCα knockdown in AnxA6 expressing A431 cells reduces T654-EGFR phosphorylation, but restores EGFR tyrosine phosphorylation, clonogenic growth and EGFR degradation. These findings correlate with AnxA6 interacting with EGFR, and elevated AnxA6 levels promoting PKCα membrane association and interaction with EGFR. Stable expression of the cytosolic N-terminal mutant AnxA6(1-175), which cannot promote PKCα membrane recruitment, does not increase T654-EGFR phosphorylation or the association of PKCα with EGFR. AnxA6 overexpression does not inhibit tyrosine phosphorylation of the T654A EGFR mutant, which cannot be phosphorylated by PKCα. Most strikingly, stable plasma membrane anchoring of AnxA6 is sufficient to recruit PKCα even in the absence of EGF or Ca(2+). In summary, AnxA6 is a new PKCα scaffold to promote PKCα-mediated EGFR inactivation through increased membrane targeting of PKCα and EGFR/PKCα complex formation.
Collapse
Affiliation(s)
- M Koese
- Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
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.
Collapse
|
36
|
PKCα and ERβ Are Associated with Triple-Negative Breast Cancers in African American and Caucasian Patients. Int J Breast Cancer 2012; 2012:740353. [PMID: 22500240 PMCID: PMC3299310 DOI: 10.1155/2012/740353] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 12/18/2011] [Indexed: 01/05/2023] Open
Abstract
Although the incidence of breast cancer in the United States is higher in Caucasian women compared with African American women, African-American patients have more aggressive disease as characterized by a higher percentage of triple-negative breast cancers (TNBCs), high-grade tumors, and a higher mortality rate. PKCα is a biomarker associated with endocrine resistance and poor prognosis and ERβ is emerging as a protective biomarker. Immunohistochemical analysis of ERβ and PKCα expression was performed on 198 formalin-fixed paraffin-embedded primary infiltrating ductal carcinomas from 105 African-American and 93 Caucasian patients. PKCα is positively correlated with TNBC in patients of both races and with high tumor grade in African-American patients. Patients with TNBC express less nuclear ERβ compared with all other subtypes. We find no difference in frequency or intensity of PKCα or ERβ expression between African-American and Caucasian patients. PKCα and ERβ are discussed as potential therapeutic targets for the treatment of patients with TNBC.
Collapse
|
37
|
Urtreger AJ, Kazanietz MG, Bal de Kier Joffé ED. Contribution of individual PKC isoforms to breast cancer progression. IUBMB Life 2011; 64:18-26. [DOI: 10.1002/iub.574] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 08/10/2011] [Indexed: 12/20/2022]
|
38
|
Curcumin sensitizes chemotherapeutic drugs via modulation of PKC, telomerase, NF-κB and HDAC in breast cancer. Ther Deliv 2011; 2:1275-93. [DOI: 10.4155/tde.11.97] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Background: Several tumor markers are overexpressed in breast cancer. Chemotherapy in breast cancer fails due to resistance to chemotherapeutic drugs. A phytochemical such as curcumin can be used in a therapeutic modality as it elicits anti-tumor effects. Methods: Action of curcumin on the expression of several tumor markers, such as protein kinase C, telomerase, NF-κB and histone deacetylase in MCF-7 (ER positive), MDA-MB-231 (ER negative), MCF-12F (control) and also in mice mammary tumors were investigated. Results: Curcumin downregulated the expression of tumor markers both in vitro and in vivo and sensitized tumor cells to the chemotherapeutic drugs cyclophosphamide and paclitaxel. Discussion: Curcumin may be of considerable value in synergistic therapy of cancer such that the drug dose level could be minimized reducing the associated toxicity.
Collapse
|
39
|
Kao HH, Wu CJ, Won SJ, Shin JW, Liu HS, Su CL. Kinase gene expression and subcellular protein expression pattern of protein kinase C isoforms in curcumin-treated human hepatocellular carcinoma Hep 3B cells. PLANT FOODS FOR HUMAN NUTRITION (DORDRECHT, NETHERLANDS) 2011; 66:136-142. [PMID: 21556896 DOI: 10.1007/s11130-011-0228-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Curcumin, a yellow component of turmeric or curry powder, has been demonstrated to exhibit anti-carcinogenic effects in vitro, in vivo, and in human clinical trials. One of its molecular targets is protein kinase C (PKC) which has been reported to play essential roles in apoptosis, cell proliferation, and carcinogenesis. In this study, PKC mRNA expression was significantly inhibited in curcumin-treated human hepatocellular carcinoma (HCC) Hep 3B cells identified using a kinase cDNA microarray. Furthermore, curcumin decreased total protein expression of all PKCs in a time-related manner by immunoblotting of whole cell lysates, nuclear, membrane, and cytosolic fractions. In cytosolic fraction, the expression of PKC-α was totally inhibited by curcumin. In contrast, the expression levels of PKC-ζ and -μ were dramatically increased. Increases in expression of PKC-δ and PKC-ζ in the membrane and nucleus, and PKC-ι in the membrane were detected. In summary, the changes in expression and distribution of subcellular PKC isoforms in curcumin-treated Hep 3B cells suggest possible PKC-associated anti-tumor mechanisms of curcumin and provide alternative therapies for human HCC.
Collapse
Affiliation(s)
- Hsin-Hsin Kao
- Department of Food Nutrition, Chung Hwa University of Medical Technology, No. 89, Wen-Hwa 1st Street, Jen-Te, Tainan, 717, Taiwan
| | | | | | | | | | | |
Collapse
|
40
|
Kim J, Thorne SH, Sun L, Huang B, Mochly-Rosen D. Sustained inhibition of PKCα reduces intravasation and lung seeding during mammary tumor metastasis in an in vivo mouse model. Oncogene 2010; 30:323-33. [PMID: 20856202 PMCID: PMC3767436 DOI: 10.1038/onc.2010.415] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Metastasis is the major reason for breast cancer-related deaths. Although there is a host of indirect evidence for a role of PKCα in primary breast cancer growth, its role in the molecular pathways leading to metastasis have not been comprehensively studied. By treating mice with αV5-3, a novel peptide inhibitor selective for PKCα, we were able to determine how PKCα regulates metastasis of mammary cancer cells using a syngeneic and orthotopic model. The primary tumor growth was not affected by αV5-3 treatment. However, the mortality rate was reduced and metastasis in the lung decreased by more than 90% in the αV5-3-treated mice relative to the control-treated mice. αV5-3 treatment reduced intravasation by reducing MMP-9 activities. αV5-3 treatment also reduced lung seeding of tumor cells and decreased cell migration, effects that were accompanied by a reduction in NFκB-activity and cell surface levels of the CXCL12 receptor, CXCR4. αV5-3 treatment caused no apparent toxicity in non-tumor bearing naïve mice. Rather, inhibiting PKCα protected against liver damage and increased the number of immune cells in tumor-bearing mice. Importantly, αV5-3 showed superior efficacy relative to anti-CXCR4 antibody in reducing metastasis, in vivo. Together, these data show that pharmacological inhibition of PKCα effectively reduces mammary cancer metastasis by targeting intravasation and lung seeding steps in the metastatic process and suggest that PKCα-specific inhibitors, such as αV5-3, can be used to study the mechanistic roles of PKCα specifically and may provide a safe and effective treatment for the prevention of lung metastasis of breast cancer patients.
Collapse
Affiliation(s)
- J Kim
- Department of Chemical and Systems Biology, Stanford University, School of Medicine, Stanford, CA 94305-5174, USA
| | | | | | | | | |
Collapse
|
41
|
Jiang J, Cole D, Westwood N, Macpherson L, Farzaneh F, Mufti G, Tavassoli M, Gäken J. Crucial Roles for Protein Kinase C Isoforms in Tumor-Specific Killing by Apoptin. Cancer Res 2010; 70:7242-52. [DOI: 10.1158/0008-5472.can-10-1204] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
42
|
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.
Collapse
Affiliation(s)
- Gry Kalstad Lønne
- Center for Molecular Pathology, Department of Laboratory Medicine, Lund University, Malmö University Hospital, SE- 205 02 Malmö, Sweden.
| | | | | | | | | | | |
Collapse
|
43
|
Köck K, Koenen A, Giese B, Fraunholz M, May K, Siegmund W, Hammer E, Völker U, Jedlitschky G, Kroemer HK, Grube M. Rapid modulation of the organic anion transporting polypeptide 2B1 (OATP2B1, SLCO2B1) function by protein kinase C-mediated internalization. J Biol Chem 2010; 285:11336-47. [PMID: 20159975 DOI: 10.1074/jbc.m109.056457] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Members of the organic anion transporting polypeptide (OATP) family are involved in various pharmacological, pathophysiological, and physiological processes, such as hepatic drug uptake, progress of cancer, or transport of hormones. Although variability in expression and function of OATPs has been investigated in detail, data concerning regulation are rather limited. Here, we report a novel mechanism for rapid regulation of OATP2B1 mediated by protein kinase C (PKC) resulting in significant changes of transport activity. PKC activation by the phorbol ester (phorbol 12-myristate 13-acetate, PMA) resulted in increased phosphorylation of OATP2B1 as well as reduced OATP2B1 transport activity with a decrease in V(max) of E(1)S uptake (288 +/- 21 (control) versus 165 +/- 16 pmol/min/mg of protein (PMA)). This effect was sensitive to the PKC inhibitor bisindolylmaleimide I (BIM-I). Confocal microscopy, fluorescence-based internalization assay, and live-cell imaging using green fluorescent protein-tagged OATP2B1 revealed that transport inhibition was due to internalization of the transporter. Furthermore, colocalization with LAMP-2 and chloroquine-sensitive degradation of OATP2B1 suggest that the internalized protein is targeted to a lysosomal degradation pathway. With regard to the underlying mechanism inhibition of caveolin/lipid raft-mediated endocytosis failed to prevent OATP2B1 internalization, whereas inhibition of clathrin-mediated processes blocked OATP2B1 sequestration. However, small interfering RNA-mediated clathrin knock-down affected general trafficking of OATP2B1 and resulted in intracellular accumulation in the absence of PMA. In conclusion, our data demonstrate that OATP2B1 function is regulated by PKC-mediated, clathrin-dependent internalization and followed by lysosomal degradation. Furthermore, internalization could be shown in an ex vivo placenta perfusion. Our findings represent a new, rapid mechanism in regulation of human OATPs.
Collapse
Affiliation(s)
- Kathleen Köck
- Department of Pharmacology, Research Center of Pharmacology and Experimental Therapeutics, Ernst Moritz Arndt University, 17487 Greifswald, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Gökmen-Polar Y, Mehta R, Tuzmen S, Mousses S, Thorat MA, Sanders KL, Turbin D, Leung S, Huntsman DG, Sledge GW, Badve S. Differential subcellular expression of protein kinase C betaII in breast cancer: correlation with breast cancer subtypes. Breast Cancer Res Treat 2010; 124:327-35. [PMID: 20099025 DOI: 10.1007/s10549-010-0733-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 01/06/2010] [Indexed: 11/24/2022]
Abstract
Protein kinase C betaII (PKCβII) represents a novel potential target for anticancer therapies in breast cancer. In order to identify patient subgroups which might benefit from PKC-targeting therapies, we investigated the expression of PKCβII in human breast cancer cell lines and in a tissue microarray (TMA). We first screened breast cancer cell line representatives of breast cancer subtypes for PKCβII expression at the mRNA and at the protein levels. We analyzed a TMA comprising of tumors from 438 patients with a median followup of 15.4 years for PKCβII expression by immunohistochemistry along with other prognostic factors in breast cancer. Among a panel of human breast cancer cell lines, only MDA-MB-436, a triple negative basal cell line, showed overexpression for PKCβII both at the mRNA and at the protein levels. In breast cancer patients, cytoplasmic expression of PKCβII correlated positively with human epidermal growth factor receptor-2 (HER-2; P = 0.01) and Ki-67 (P = 0.016), while nuclear PKCβII correlated positively with estrogen receptor (ER; P = 0.016). The positive correlation of CK5/6 with cytoplasmic PKCβII (P = 0.033) lost statistical significance after adjusting for multiple comparisons (P = 0.198). Cytoplasmic PKCβII did not correlate with cyclooxygenase (COX-2; P = 0.925) and vascular endothelial growth factor (P = 1). There was no significant association between PKCβII staining and overall survival. Cytoplasmic PKCβII correlates with HER-2 and Ki-67, while nuclear PKCβII correlates with ER in breast cancer. Our study suggests the necessity for assessing the subcellular localization of PKCβII in breast cancer subtypes when evaluating the possible effectiveness of PKCβII-targeting agents.
Collapse
Affiliation(s)
- Yesim Gökmen-Polar
- Department of Medicine, Indiana University School of Medicine, Walther Hall, 980 W Walnut Street, C230, Indianapolis, IN 46202, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
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.
Collapse
Affiliation(s)
- Yiyun Zhang
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | | | | | | | | | | |
Collapse
|
46
|
Protein kinase Cdelta expression in breast cancer as measured by real-time PCR, western blotting and ELISA. Br J Cancer 2008; 99:1644-50. [PMID: 19002183 PMCID: PMC2584939 DOI: 10.1038/sj.bjc.6604728] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The protein kinase C (PKC) family of genes encode serine/threonine kinases that regulate proliferation, apoptosis, cell survival and migration. Multiple isoforms of PKC have been described, one of which is PKCδ. Currently, it is unclear whether PKCδ is involved in promoting or inhibiting cancer formation/progression. The aim of this study was therefore to investigate the expression of PKCδ in human breast cancer and relate its levels to multiple parameters of tumour progression. Protein kinase Cδ expression at the mRNA level was measured using real-time PCR (n=208) and at protein level by both immunoblotting (n=94) and ELISA (n=98). Following immunoblotting, two proteins were identified, migrating with molecular masses of 78 and 160 kDa. The 78 kDa protein is likely to be the mature form of PKCδ but the identity of the 160 kDa form is unknown. Levels of both these proteins correlated weakly but significantly with PKCδ concentrations determined by ELISA (for the 78 kDa form, r=0.444, P<0.005, n=91 and for the 160 kDa form, r=0.237, P=0.023, n=91) and with PKCδ mRNA levels (for the 78 kDa form, r=0.351, P=0.001, n=94 and for the 160 kDa form, r=0.216, P=0.037, n=94). Protein kinase Cδ mRNA expression was significantly higher in oestrogen receptor (ER)-positive compared with ER-negative tumours (P=0.007, Mann–Whitney U-test). Increasing concentrations of PKCδ mRNA were associated with reduced overall patient survival (P=0.004). Our results are consistent with a role for PKCδ in breast cancer progression.
Collapse
|
47
|
Ali AS, Ali S, El-Rayes BF, Philip PA, Sarkar FH. Exploitation of protein kinase C: a useful target for cancer therapy. Cancer Treat Rev 2008; 35:1-8. [PMID: 18778896 DOI: 10.1016/j.ctrv.2008.07.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 07/29/2008] [Accepted: 07/30/2008] [Indexed: 12/11/2022]
Abstract
Protein kinase C is a family of serine/threonine kinases. The PKC family is made up of at least 12 isozymes, which have a role in cell proliferation, differentiation, angiogenesis, and apoptosis. Activation of PKC isozyme is dependent on tyrosine-kinase receptors and G-protein-coupled receptors. PKC isozymes regulate multiple signaling pathways including PI3-K/Akt, MAPK, and GSK-3beta. PKC isozymes have variable roles in tumor biology which in part depend on the cell type and intracellular localization. PKC isozymes are commonly dysregulated in the cancer of the prostate, breast, colon, pancreatic, liver, and kidney. Currently, several classes of PKC inhibitors are being evaluated in clinical trials and several challenges in targeting PKC isozymes have been recently identified. In conclusion, PKC remains a promising target for cancer prevention and therapy.
Collapse
Affiliation(s)
- Ashhar S Ali
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, 4100 John R Street, Detroit, MI 48201, USA
| | | | | | | | | |
Collapse
|
48
|
PKCdelta mediates thrombin-augmented fibroblast-mediated collagen gel contraction. Biochem Biophys Res Commun 2008; 369:1199-203. [PMID: 18342628 DOI: 10.1016/j.bbrc.2008.03.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Accepted: 03/06/2008] [Indexed: 11/21/2022]
Abstract
Fibroblast-mediated collagen gel contraction has been used as an in vitro model of tissue remodeling. Thrombin is one of the mediators present in the milieu of airway inflammation and may be involved in airway tissue remodeling. We have previously reported that thrombin stimulates fibroblast-mediated collagen gel contraction partially through the PAR1/PKCepsilon signaling pathway [Q. Fang, X. Liu, S. Abe, T. Kobayashi, X.Q. Wang, T. Kohyama, M. Hashimoto, T. Wyatt, S.I. Rennard, Thrombin induces collagen gel contraction partially through PAR1 activation and PKC-epsilon, Eur. Respir. J. 24 (2004) 918-924]. Here, we further report that the delta-isoform of PKC (PKCdelta) is also activated by thrombin and involved in the thrombin-mediated augmentation of collagen gel contraction. Thrombin (10nM) significantly increased PKCdelta activity (over 5-fold increase after 15-30min stimulation) and stimulated phosphorylation of PKCdelta. Rottlerin, a PKCdelta inhibitor, completely inhibited activation of PKCdelta and partially blocked collagen gel contraction stimulated by thrombin. Similarly, PKCdelta-specific siRNA significantly inhibited PKCdelta activation without affecting PKCepsilon expression and activation. Furthermore, suppression of PKCdelta by siRNA resulted in partial blockade of thrombin-augmented collagen gel contraction. These results suggest that thrombin contributes to the tissue remodeling in inflammatory airways and lung diseases at least partially through both PKCdelta and PKCepsilon signaling.
Collapse
|