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Burmi RS, Box GM, Wazir U, Hussain HA, Davies JA, Court WJ, Eccles SA, Jiang WG, Mokbel K, Harvey AJ. Breast Tumour Kinase (Brk/PTK6) Contributes to Breast Tumour Xenograft Growth and Modulates Chemotherapeutic Responses In Vitro. Genes (Basel) 2022; 13:genes13030402. [PMID: 35327957 PMCID: PMC8950834 DOI: 10.3390/genes13030402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/21/2022] [Accepted: 02/21/2022] [Indexed: 12/07/2022] Open
Abstract
Breast tumour kinase (Brk/PTK6) is overexpressed in up to 86% of breast cancers and is associated with poorer patient outcomes. It is considered a potential therapeutic target in breast cancer, even though the full spectrum of its kinase activity is not known. This study investigated the role of the kinase domain in promoting tumour growth and its potential in sensitising triple negative breast cancer cells to standard of care chemotherapy. Triple negative human xenograft models revealed that both kinase-inactive and wild-type Brk promoted xenograft growth. Suppression of Brk activity in cells subsequently co-treated with the chemotherapy agents doxorubicin or paclitaxel resulted in an increased cell sensitivity to these agents. In triple negative breast cancer cell lines, the inhibition of Brk kinase activity augmented the effects of doxorubicin or paclitaxel. High expression of the alternatively spliced isoform, ALT-PTK6, resulted in improved patient outcomes. Our study is the first to show a role for kinase-inactive Brk in human breast tumour xenograft growth; therefore, it is unlikely that kinase inhibition of Brk, in isolation, would halt tumour growth in vivo. Breast cancer cell responses to chemotherapy in vitro were kinase-dependent, indicating that treatment with kinase inhibitors could be a fruitful avenue for combinatorial treatment. Of particular prognostic value is the ratio of ALT-PTK6:Brk expression in predicating patient outcomes.
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Affiliation(s)
- Rajpal S. Burmi
- Centre for Genome Engineering and Maintenance, Institute for Health Medicine and Environments, Brunel University London, Uxbridge UB8 3PH, UK; (R.S.B.); (H.A.H.); (J.A.D.)
| | - Gary M. Box
- The Cancer Research UK Cancer Therapeutics Unit, McElwain Laboratories, The Institute of Cancer Research, Sutton SM2 5NG, UK; (G.M.B.); (W.J.C.); (S.A.E.)
| | - Umar Wazir
- The London Breast Institute, Princess Grace Hospital, London W1U 5NY, UK; (U.W.); (K.M.)
| | - Haroon A. Hussain
- Centre for Genome Engineering and Maintenance, Institute for Health Medicine and Environments, Brunel University London, Uxbridge UB8 3PH, UK; (R.S.B.); (H.A.H.); (J.A.D.)
| | - Julie A. Davies
- Centre for Genome Engineering and Maintenance, Institute for Health Medicine and Environments, Brunel University London, Uxbridge UB8 3PH, UK; (R.S.B.); (H.A.H.); (J.A.D.)
| | - William J. Court
- The Cancer Research UK Cancer Therapeutics Unit, McElwain Laboratories, The Institute of Cancer Research, Sutton SM2 5NG, UK; (G.M.B.); (W.J.C.); (S.A.E.)
| | - Suzanne A. Eccles
- The Cancer Research UK Cancer Therapeutics Unit, McElwain Laboratories, The Institute of Cancer Research, Sutton SM2 5NG, UK; (G.M.B.); (W.J.C.); (S.A.E.)
| | - Wen G. Jiang
- Cardiff China Medical Research Collaborative, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK;
| | - Kefah Mokbel
- The London Breast Institute, Princess Grace Hospital, London W1U 5NY, UK; (U.W.); (K.M.)
| | - Amanda J. Harvey
- Centre for Genome Engineering and Maintenance, Institute for Health Medicine and Environments, Brunel University London, Uxbridge UB8 3PH, UK; (R.S.B.); (H.A.H.); (J.A.D.)
- Correspondence: ; Tel.: +44-(0)1895-267264
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Chen Z, Song H, Zeng X, Quan M, Gao Y. Screening and discrimination of optimal prognostic genes for pancreatic cancer based on a prognostic prediction model. G3 (BETHESDA, MD.) 2021; 11:6355586. [PMID: 34499727 PMCID: PMC8527504 DOI: 10.1093/g3journal/jkab296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/14/2021] [Indexed: 02/06/2023]
Abstract
The prognosis of pancreatic cancer is poor because patients are usually asymptomatic in the early stage and the early diagnostic rate is low. Therefore, in this study, we aimed to identify potential prognosis-related genes in pancreatic cancer to improve diagnosis and the outcome of patients. The mRNA expression profile data from The Cancer Genome Atlas database and GSE79668, GSE62452, and GSE28735 datasets from Gene Expression Omnibus were downloaded. The prognosis-relevant genes and clinical factors were analyzed using Cox regression analysis and the optimal gene sets were screened using the Cox proportional model. Next, the Kaplan-Meier survival analysis was used to evaluate the relationship between risk grouping and patient prognosis. Finally, an optimal gene-based prognosis prediction model was constructed and validated using a test dataset to discriminate the model accuracy and reliability. The results showed that 325 expression variable genes were identified, and 48 prognosis-relevant genes and three clinical factors, including lymph node stage (pathologic N), new tumor, and targeted molecular therapy were preliminarily obtained. In addition, a gene set containing 16 optimal genes was identified and included FABP6, MAL, KIF19, and REG4, which were significantly associated with the prognosis of pancreatic cancer. Moreover, a prognosis prediction model was constructed and validated to be relatively accurate and reliable. In conclusion, a gene set consisting of 16 prognosis-related genes was identified and a prognosis prediction model was constructed, which is expected to be applicable in the clinical diagnosis and treatment guidance of pancreatic cancer in the future.
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Affiliation(s)
| | | | | | - Ming Quan
- Department of Oncology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200123, China
| | - Yong Gao
- Department of Oncology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200123, China
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Sahu R, Pattanayak SP. Strategic Developments & Future Perspective on Gene Therapy for Breast Cancer: Role of mTOR and Brk/ PTK6 as Molecular Targets. Curr Gene Ther 2021; 20:237-258. [PMID: 32807051 DOI: 10.2174/1566523220999200731002408] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/16/2020] [Accepted: 07/24/2020] [Indexed: 12/24/2022]
Abstract
Breast cancer is a serious health issue and a major concern in biomedical research. Alteration in major signaling (viz. PI3K-AKT-mTOR, Ras-Raf-MEK-Erk, NF-kB, cyclin D1, JAK-STAT, Wnt, Notch, Hedgehog signaling and apoptotic pathway) contributes to the development of major subtypes of mammary carcinoma such as HER2 positive, TNBC, luminal A and B and normal-like breast cancer. Further, mutation and expression parameters of different genes involved in the growth and development of cells play an important role in the progress of different types of carcinoma, making gene therapy an emerging new therapeutic approach for the management of life-threatening diseases like cancer. The genetic targets (oncogenes and tumor suppressor genes) play a major role in the formation of a tumor. Brk/PTK6 and mTOR are two central molecules that are involved in the regulation of numerous signaling related to cell growth, proliferation, angiogenesis, survival, invasion, metastasis, apoptosis, and autophagy. Since these two proteins are highly upregulated in mammary carcinogenesis, this can be used as targeted genes for the treatment of breast cancer. However, not much work has been done on them. This review highlights the therapeutic significance of Brk and mTOR and their associated signaling in mammary carcinogenesis, which may provide a strategy to develop gene therapy for breast cancer management.
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Affiliation(s)
- Roja Sahu
- Division of Advanced Pharmacology, Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand- 835 215, India
| | - Shakti P Pattanayak
- Division of Advanced Pharmacology, Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand- 835 215, India,Department of Pharmacy, Central University of South Bihar (Gaya), Bihar-824 236, India
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Liu W, Xu C, Meng Q, Kang P. The clinical value of kinesin superfamily protein 2A in hepatocellular carcinoma. Clin Res Hepatol Gastroenterol 2021; 45:101527. [PMID: 33713978 DOI: 10.1016/j.clinre.2020.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/28/2020] [Accepted: 08/24/2020] [Indexed: 02/04/2023]
Abstract
BACKGROUND This study aimed to investigate the clinical value of kinesin superfamily protein 2A (KIF2A) in hepatocellular carcinoma (HCC) patients. METHODS This study retrospectively analyzed 196 HCC patients who underwent hepatic resection, and their preoperative clinical characteristics were collected from the medical records. Immunohistochemical (IHC) assay was performed to detect KIF2A expression, subsequently KIF2A expression was evaluated by a semi-quantitative IHC score (according to IHC staining density and intensity of positively stained cells) and then graded as KIF2A-/KIF2A+/KIF2A++/KIF2A+++ for analysis. Overall survival (OS) was calculated from the date of resection to the date of death. RESULTS Compared to adjacent tissue, both KIF2A IHC score and grade were higher in tumor tissue (Both P < 0.001). Tumor KIF2A expression was positively correlated with performance status score (P = 0.001), multifocal tumor nodule (P = 0.018), largest tumor size (P = 0.015) and Barcelona clinic liver cancer stage (P < 0.001). Regarding live function indexes, tumor KIF2A expression was positively associated with aspartate aminotransferase (P = 0.006). As to tumor markers, tumor KIF2A expression showed a trend to be positively correlated with alpha fetoprotein (P = 0.060) and carbohydrate antigen 199 (P = 0.053), but no statistical significance. Kaplan-Meier curve showed that tumor higher KIF2A expression was associated with worse OS (P < 0.001), which was further validated by multivariate Cox's regression analysis as higher an independent factor predicting shorter OS (P = 0.001). CONCLUSION KIF2A is upregulated in tumor tissue than adjacent tissue, importantly, tumor KIF2A is associated with worse liver function, raised tumor stage and poor OS in HCC patients.
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Affiliation(s)
- Wenjuan Liu
- Department of Infectious Diseases, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Chunlin Xu
- Department of Infectious Diseases, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Qingyang Meng
- Department of Infectious Diseases, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Peng Kang
- Department of Infectious Diseases, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.
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Barakeh DH, Aljelaify R, Bashawri Y, Almutairi A, Alqubaishi F, Alnamnakani M, Almubarak L, Al Naeem A, Almushawah F, Alrashed M, Abedalthagafi M. Landscape of somatic mutations in breast cancer: new opportunities for targeted therapies in Saudi Arabian patients. Oncotarget 2021; 12:686-697. [PMID: 33868589 PMCID: PMC8021026 DOI: 10.18632/oncotarget.27909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/19/2021] [Indexed: 12/24/2022] Open
Abstract
Breast cancer (BCa) ranks first in incidence rate among cancers in Arab females. The association between genetic polymorphisms in tumor suppressor genes and the risk of BCa has been studied in many ethnic populations with conflicting conclusions while Arab females and Saudi Arabian studies are still lacking. We screened a cohort of Saudi BCa patients by NGS using a bespoke gene panel to clarify the genetic landscape of this population, correlating and assessing genetic findings with clinical outcomes. We identified a total of 263 mutations spanning 51 genes, including several frequently mutated. Among the genes analyzed, the highest mutation rates were found in PIK3CA (12.9%), BRCA2 (11.7%), BRCA1 (10.2%), TP53 (6.0%), MSH2 (3.8%), PMS2 (3.8%), BARD1 (3.8%), MLH1 (3.4%), CDH1 (3.0%), RAD50 (3.0%), MSH6 (3.0%), NF1 (2.6%), in addition to others. We identified multiple common recurrent variants and previously reported mutations. We also identified 46 novel variants in 22 genes that were predicted to have a pathogenic effect. Survival analysis according to the four most common mutations (BRCA1, BRCA2, TP53, and PIK3CA) showed reduced survival in BRCA1 and BRCA2-mutant patients compared to total patients. Moreover, BRCA2 was demonstrated as an independent predictor of reduced survival using independent Cox proportional hazard models. We reveal the landscape of the mutations associated with BCa in Saudi women, highlighting the importance of routine genetic sequencing in implementation of precision therapies in KSA.
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Affiliation(s)
- Duna H Barakeh
- Department of Pathology, King Saud University Medical City, Riyadh, Kingdom of Saudi Arabia
| | - Rasha Aljelaify
- Genomics Research Department, Saudi Human Genome Project, King Fahad Medical City and King Abdulaziz City for Science and Technology, Riyadh, Kingdom of Saudi Arabia
| | - Yara Bashawri
- Department of Biostatistics, Research Centre, King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia
| | - Amal Almutairi
- Genomics Research Department, Saudi Human Genome Project, King Fahad Medical City and King Abdulaziz City for Science and Technology, Riyadh, Kingdom of Saudi Arabia
| | - Fatimah Alqubaishi
- Genomics Research Department, Saudi Human Genome Project, King Fahad Medical City and King Abdulaziz City for Science and Technology, Riyadh, Kingdom of Saudi Arabia
| | - Mohammed Alnamnakani
- Department of Pathology, King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia
| | - Latifa Almubarak
- Genomics Research Department, Saudi Human Genome Project, King Fahad Medical City and King Abdulaziz City for Science and Technology, Riyadh, Kingdom of Saudi Arabia
| | - Abdulrahman Al Naeem
- Department of Radiology, King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia
| | - Fatema Almushawah
- Department of Surgery, King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia
| | - May Alrashed
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia.,Chair of Medical and Molecular Genetics Research, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Malak Abedalthagafi
- Genomics Research Department, Saudi Human Genome Project, King Fahad Medical City and King Abdulaziz City for Science and Technology, Riyadh, Kingdom of Saudi Arabia
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Ang HL, Yuan Y, Lai X, Tan TZ, Wang L, Huang BB, Pandey V, Huang RYJ, Lobie PE, Goh BC, Sethi G, Yap CT, Chan CW, Lee SC, Kumar AP. Putting the BRK on breast cancer: From molecular target to therapeutics. Am J Cancer Res 2021; 11:1115-1128. [PMID: 33391524 PMCID: PMC7738883 DOI: 10.7150/thno.49716] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/01/2020] [Indexed: 12/13/2022] Open
Abstract
BReast tumor Kinase (BRK, also known as PTK6) is a non-receptor tyrosine kinase that is highly expressed in breast carcinomas while having low expression in the normal mammary gland, which hints at the oncogenic nature of this kinase in breast cancer. In the past twenty-six years since the discovery of BRK, an increasing number of studies have strived to understand the cellular roles of BRK in breast cancer. Since then, BRK has been found both in vitro and in vivo to activate a multitude of oncoproteins to promote cell proliferation, metastasis, and cancer development. The compelling evidence concerning the oncogenic roles of BRK has also led, since then, to the rapid and exponential development of inhibitors against BRK. This review highlights recent advances in BRK biology in contributing to the “hallmarks of cancer”, as well as BRK's therapeutic significance. Importantly, this review consolidates all known inhibitors of BRK activity and highlights the connection between drug action and BRK-mediated effects. Despite the volume of inhibitors designed against BRK, none have progressed into clinical phase. Understanding the successes and challenges of these inhibitor developments are crucial for the future improvements of new inhibitors that can be clinically relevant.
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Targeting protein tyrosine kinase 6 in cancer. Biochim Biophys Acta Rev Cancer 2020; 1874:188432. [PMID: 32956764 DOI: 10.1016/j.bbcan.2020.188432] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 07/27/2020] [Accepted: 09/04/2020] [Indexed: 11/21/2022]
Abstract
Protein tyrosine kinase 6 (PTK6) is the most well studied member of the PTK6 family of intracellular tyrosine kinases. While it is expressed at highest levels in differentiated cells in the regenerating epithelial linings of the gastrointestinal tract and skin, induction and activation of PTK6 is detected in several cancers, including breast and prostate cancer where high PTK6 expression correlates with worse outcome. PTK6 expression is regulated by hypoxia and cell stress, and its kinase activity is induced by several growth factor receptors implicated in cancer including members of the ERBB family, IGFR1 and MET. Activation of PTK6 at the plasma membrane has been associated with the epithelial mesenchymal transition and tumor metastasis. Several lines of evidence indicate that PTK6 has context dependent functions that depend on cell type, intracellular localization and kinase activation. Systemic disruption of PTK6 has been shown to reduce tumorigenesis in mouse models of breast and prostate cancer, and more recently small molecule inhibitors of PTK6 have exhibited efficacy in inhibiting tumor growth in animal models. Here we review data that suggest targeting PTK6 may have beneficial therapeutic outcomes in some cancers.
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Thakur MK, Birudukota S, Swaminathan S, Battula SK, Vadivelu S, Tyagi R, Gosu R. Co-crystal structures of PTK6: With Dasatinib at 2.24 Å, with novel imidazo[1,2-a]pyrazin-8-amine derivative inhibitor at 1.70 Å resolution. Biochem Biophys Res Commun 2016; 482:1289-1295. [PMID: 27993680 DOI: 10.1016/j.bbrc.2016.12.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 12/03/2016] [Indexed: 12/29/2022]
Abstract
Human Protein tyrosine kinase 6 (PTK6)(EC:2.7.10.2), also known as the breast tumor kinase (BRK), is an intracellular non-receptor Src-related tyrosine kinase expressed five-fold or more in human breast tumors and breast cancer cell lines but its expression being low or completely absent from normal mammary gland. There is a recent interest in targeting PTK6-positive breast cancer by developing small molecule inhibitor against PTK6. Novel imidazo[1,2-a]pyrazin-8-amines (IPA) derivative compounds and FDA approved drug, Dasatinib are reported to inhibit PTK6 kinase activity with IC50 in nM range. To understand binding mode of these compounds and key interactions that drive the potency against PTK6, one of the IPA compounds and Dasatinib were chosen to study through X-ray crystallography. The recombinant PTK6 kinase domain was purified and co-crystallized at room temperature by the sitting-drop vapor diffusion method, collected X-ray diffraction data at in-house and resolved co-crystal structure of PTK6-KD with Dasatinib at 2.24 Å and with IPA compound at 1.70 Å resolution. Both these structures are in DFG-in & αC-helix-out conformation with unambiguous electron density for Dasatinib or IPA compound bound at the ATP-binding pocket. Relative difference in potency between Dasatinib and IPA compound is delineated through the additional interactions derived from the occupation of additional pocket by Dasatinib at gatekeeper area. Refined crystallographic coordinates for the kinase domain of PTK6 in complex with IPA compound and Dasatinib have been submitted to Protein Data Bank under the accession number 5DA3 and 5H2U respectively.
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Affiliation(s)
- Manish Kumar Thakur
- Department of Biochemistry, University of Mysore, Mysore, 570005, India; Department of Structural Biology, Jubilant Biosys Ltd, Bangalore, 560022, India
| | | | | | | | - Sarvanan Vadivelu
- Department of Structural Biology, Jubilant Biosys Ltd, Bangalore, 560022, India
| | - Rajiv Tyagi
- Department of Structural Biology, Jubilant Biosys Ltd, Bangalore, 560022, India
| | - Ramachandraiah Gosu
- Department of Biochemistry, University of Mysore, Mysore, 570005, India; Department of Structural Biology, Jubilant Biosys Ltd, Bangalore, 560022, India.
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Up-regulation of KIF14 is a predictor of poor survival and a novel prognostic biomarker of chemoresistance to paclitaxel treatment in cervical cancer. Biosci Rep 2016; 36:BSR20150314. [PMID: 27128470 PMCID: PMC4820787 DOI: 10.1042/bsr20150314] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 01/26/2016] [Indexed: 01/10/2023] Open
Abstract
KIF14 may serve as a predictor of poor survival and a novel prognostic biomarker of chemoresistance to paclitaxel treatment in cervical cancer. Kinesin family member 14 (KIF14) is a member of kinesin family proteins which have been found to be dysregulated in various cancer types. However, the expression of KIF14 and its potential prognostic significance have not been investigated in cervical cancer. Real-time PCR was performed to assess the expression levels of KIF14 in 47 pairs of cervical cancer tissues and their matched normal tissues from patients who had not been exposed to chemotherapy as well as tissue samples from 57 cervical cancer patients who are sensitive to paclitaxel treatment and 53 patients who are resistant. The association between KIF14 expression levels in tissue and clinicopathological features or chemosensitivity was examined. Kaplan–Meier analysis and Cox proportional hazards model were applied to assess the correlation between KIF14 expression levels and overall survival (OS) of cervical cancer patients. KIF14 expression levels were significantly increased in cervical cancer tissues compared with matched non-cancerous tissues and it was higher in tissues of patients who are chemoresistant compared with those who are chemosensitive. KIF14 expression was positively associated with high tumour stage (P=0.0044), lymph node metastasis (P=0.0034) and chemoresistance (P<0.0001). Kaplan–Meier analysis showed that high KIF14 expression levels predicted poor survival in patients with (P=0.0024) or without (P=0.0028) paclitaxel treatment. Multivariate analysis revealed that KIF14 was an independent prognostic factor for OS. Our study suggests that KIF14 may serve as a predictor of poor survival and a novel prognostic biomarker of chemoresistance to paclitaxel treatment in cervical cancer.
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Rai DK, Lawrence P, Kloc A, Schafer E, Rieder E. Analysis of the interaction between host factor Sam68 and viral elements during foot-and-mouth disease virus infections. Virol J 2015; 12:224. [PMID: 26695943 PMCID: PMC4689063 DOI: 10.1186/s12985-015-0452-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 12/10/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The nuclear protein Src-associated protein of 68 kDa in mitosis (Sam68) is known to bind RNA and be involved in cellular processes triggered in response to environmental stresses, including virus infection. Interestingly, Sam68 is a multi-functional protein implicated in the life cycle of retroviruses and picornaviruses and is also considered a marker of virus-induced stress granules (SGs). Recently, we demonstrated the partial redistribution of Sam68 to the cytoplasm in FMDV infected cells, its interaction with viral protease 3C(pro), and found a significant reduction in viral titers as consequence of Sam68-specific siRNA knockdowns. Despite of that, details of how it benefits FMDV remains to be elucidated. METHODS Sam68 cytoplasmic localization was examined by immunofluorescent microscopy, counterstaining with antibodies against Sam68, a viral capsid protein and markers of SGs. The relevance of RAAA motifs in the IRES was investigated using electromobility shift assays with Sam68 protein and parental and mutant FMDV RNAs. In addition, full genome WT and mutant or G-luc replicon RNAs were tested following transfection in mammalian cells. The impact of Sam68 depletion to virus protein and RNA synthesis was investigated in a cell-free system. Lastly, through co-immunoprecipitation, structural modeling, and subcellular fractionation, viral protein interactions with Sam68 were explored. RESULTS FMDV-induced cytoplasmic redistribution of Sam68 resulted in it temporarily co-localizing with SG marker: TIA-1. Mutations that disrupted FMDV IRES RAAA motifs, with putative affinity to Sam68 in domain 3 and 4 cause a reduction on the formation of ribonucleoprotein complexes with this protein and resulted in non-viable progeny viruses and replication-impaired replicons. Furthermore, depletion of Sam68 in cell-free extracts greatly diminished FMDV RNA replication, which was restored by addition of recombinant Sam68. The results here demonstrated that Sam68 specifically co-precipitates with both FMDV 3D(pol) and 3C(pro) consistent with early observations of FMDV 3C(pro)-induced cleavage of Sam68. CONCLUSION We have found that Sam68 is a specific binding partner for FMDV non-structural proteins 3C(pro) and 3D(pol) and showed that mutations at RAAA motifs in IRES domains 3 and 4 cause a decrease in Sam68 affinity to these RNA elements and rendered the mutant RNA non-viable. Interestingly, in FMDV infected cells re-localized Sam68 was transiently detected along with SG markers in the cytoplasm. These results support the importance of Sam68 as a host factor co-opted by FMDV during infection and demonstrate that Sam68 interact with both, FMDV RNA motifs in the IRES and viral non-structural proteins 3C(pro) and 3D(pol).
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Affiliation(s)
- Devendra K Rai
- Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, USDA/ARS/NAA, P.O. Box 848, Greenport, NY, 11944, USA.
| | - Paul Lawrence
- Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, USDA/ARS/NAA, P.O. Box 848, Greenport, NY, 11944, USA.
| | - Anna Kloc
- Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, USDA/ARS/NAA, P.O. Box 848, Greenport, NY, 11944, USA.
| | - Elizabeth Schafer
- Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, USDA/ARS/NAA, P.O. Box 848, Greenport, NY, 11944, USA.
| | - Elizabeth Rieder
- Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Plum Island Animal Disease Center, USDA/ARS/NAA, P.O. Box 848, Greenport, NY, 11944, USA.
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Zhang X, Ma C, Wang Q, Liu J, Tian M, Yuan Y, Li X, Qu X. Role of KIF2A in the progression and metastasis of human glioma. Mol Med Rep 2015; 13:1781-7. [PMID: 26707290 DOI: 10.3892/mmr.2015.4700] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 11/25/2015] [Indexed: 11/06/2022] Open
Abstract
KIF2A is a member of the kinesin-13 family and is involved in cell mitosis and spindle assembly. The abnormal expression and dysfunction of KIF2A are associated with tumorigenesis and the progression of certain human cancer types; however, little is known about the expression and roles of KIF2A in glioma. In the present study, the expression of KIF2A in 35 freshly isolated human glioma tissue samples was analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC). The association between the expression of KIF2A and clinicopathological parameters were assessed using the χ(2) test. The biological functions of KIF2A on the proliferation, apoptosis, migration and invasion of glioma cells were investigated using an A172 cell line. RT-qPCR and IHC results demonstrated that the mRNA and protein expression levels of KIF2A were significantly higher in grade III-IV glioma tissues compared with those in grade I-II glioma tissues (P<0.05). No significant correlation was observed between the expression of KIF2A, and age, gender, tumor location and size (P>0.05). In vitro, KIF2A gene silencing inhibited the proliferation, migration and invasion, and induced apoptosis in cancer cells. The present data suggested that KIF2A may be important in glioma progression and may serve as a novel predictive factor and therapeutic target for glioma.
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Affiliation(s)
- Xin Zhang
- Institute of Basic Medical Sciences, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Chao Ma
- Institute of Basic Medical Sciences, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Qingjie Wang
- Institute of Basic Medical Sciences, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Jia Liu
- Institute of Basic Medical Sciences, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Mingyi Tian
- Institute of Basic Medical Sciences, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Yuchang Yuan
- Institute of Basic Medical Sciences, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Xingang Li
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Xun Qu
- Institute of Basic Medical Sciences, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
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12
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Goel RK, Lukong KE. Tracing the footprints of the breast cancer oncogene BRK - Past till present. Biochim Biophys Acta Rev Cancer 2015; 1856:39-54. [PMID: 25999240 DOI: 10.1016/j.bbcan.2015.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 04/22/2015] [Accepted: 05/09/2015] [Indexed: 02/07/2023]
Abstract
Twenty years have passed since the non-receptor tyrosine kinase, Breast tumor kinase (BRK) was cloned. While BRK is evolutionarily related to the Src family kinases it forms its own distinct sub-family referred here to as the BRK family kinases. The detection of BRK in over 60% of breast carcinomas two decades ago and more remarkably, its absence in the normal mammary gland attributed to its recognition as a mammary gland-specific potent oncogene and led BRK researchers on a wild chase to characterize the role of the enzyme in breast cancer. Where has this chase led us? An increasing number of studies have been focused on understanding the cellular roles of BRK in breast carcinoma and normal tissues. A majority of such studies have proposed an oncogenic function of BRK in breast cancers. Thus far, the vast evidence gathered highlights a regulatory role of BRK in critical cellular processes driving tumor formation such as cell proliferation, migration and metastasis. Functional characterization of BRK has identified several signaling proteins that work in concert with the enzyme to sustain such a malignant phenotype. As such targeting the non-receptor tyrosine kinase has been proposed as an attractive approach towards therapeutic intervention. Yet much remains to be explored about (a) the discrepant expression levels of BRK in cancer versus normal conditions, (b) the dependence on the enzymatic activity of BRK to promote oncogenesis and (c) an understanding of the normal physiological roles of the enzyme. This review outlines the advances made towards understanding the cellular and physiological roles of BRK, the mechanisms of action of the protein and its therapeutic significance, in the context of breast cancer.
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Affiliation(s)
- Raghuveera Kumar Goel
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Kiven Erique Lukong
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
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13
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Hussain HA, Harvey AJ. Evolution of breast cancer therapeutics: Breast tumour kinase’s role in breast cancer and hope for breast tumour kinase targeted therapy. World J Clin Oncol 2014; 5:299-310. [PMID: 25114846 PMCID: PMC4127602 DOI: 10.5306/wjco.v5.i3.299] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 03/25/2014] [Accepted: 06/03/2014] [Indexed: 02/06/2023] Open
Abstract
There have been significant improvements in the detection and treatment of breast cancer in recent decades. However, there is still a need to develop more effective therapeutic techniques that are patient specific with reduced toxicity leading to further increases in patients’ overall survival; the ongoing progress in understanding recurrence, resistant and spread also needs to be maintained. Better understanding of breast cancer pathology, molecular biology and progression as well as identification of some of the underlying factors involved in breast cancer tumourgenesis and metastasis has led to the identification of novel therapeutic targets. Over a number of years interest has risen in breast tumour kinase (Brk) also known as protein tyrosine kinase 6; the research field has grown and Brk has been described as a desirable therapeutic target in relation to tyrosine kinase inhibition as well as disruption of its kinase independent activity. This review will outline the current “state of play” with respect to targeted therapy for breast cancer, as well as discussing Brk’s role in the processes underlying tumour development and metastasis and its potential as a therapeutic target in breast cancer.
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14
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Signaling pathways in breast cancer: therapeutic targeting of the microenvironment. Cell Signal 2014; 26:2843-56. [PMID: 25093804 DOI: 10.1016/j.cellsig.2014.07.034] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 07/28/2014] [Indexed: 02/08/2023]
Abstract
Breast cancer is the most common cancer in women worldwide. Understanding the biology of this malignant disease is a prerequisite for selecting an appropriate treatment. Cell cycle alterations are seen in many cancers, including breast cancer. Newly popular targeted agents in breast cancer include cyclin dependent kinase inhibitors (CDKIs) which are agents inhibiting the function of cyclin dependent kinases (CDKs) and agents targeting proto-oncogenic signaling pathways like Notch, Wnt, and SHH (Sonic hedgehog). CDKIs are categorized as selective and non-selective inhibitors of CDK. CDKIs have been tried as monotherapy and combination therapy. The CDKI Palbocyclib is now a promising therapeutic in breast cancer. This drug recently entered phase III trial for estrogen receptor (ER) positive breast cancer after showing encouraging results in progression free survival in a phase II trials. The tumor microenvironment is now recognized as a significant factor in cancer treatment response. The tumor microenvironment is increasingly considered as a target for combination therapy of breast cancer. Recent findings in the signaling pathways in breast cancer are herein summarized and discussed. Furthermore, the therapeutic targeting of the microenvironment in breast cancer is also considered.
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15
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Mahmoud KA, Krug M, Wersig T, Slynko I, Schächtele C, Totzke F, Sippl W, Hilgeroth A. Discovery of 4-anilino α-carbolines as novel Brk inhibitors. Bioorg Med Chem Lett 2014; 24:1948-51. [DOI: 10.1016/j.bmcl.2014.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 02/25/2014] [Accepted: 03/01/2014] [Indexed: 10/25/2022]
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16
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Miah S, Goel RK, Dai C, Kalra N, Beaton-Brown E, Bagu ET, Bonham K, Lukong KE. BRK targets Dok1 for ubiquitin-mediated proteasomal degradation to promote cell proliferation and migration. PLoS One 2014; 9:e87684. [PMID: 24523872 PMCID: PMC3921129 DOI: 10.1371/journal.pone.0087684] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 01/02/2014] [Indexed: 12/13/2022] Open
Abstract
Breast tumor kinase (BRK), also known as protein tyrosine kinase 6 (PTK6), is a non-receptor tyrosine kinase overexpressed in more that 60% of human breast carcinomas. The overexpression of BRK has been shown to sensitize mammary epithelial cells to mitogenic signaling and to promote cell proliferation and tumor formation. The molecular mechanisms of BRK have been unveiled by the identification and characterization of BRK target proteins. Downstream of tyrosine kinases 1 or Dok1 is a scaffolding protein and a substrate of several tyrosine kinases. Herein we show that BRK interacts with and phosphorylates Dok1 specifically on Y362. We demonstrate that this phosphorylation by BRK significantly downregulates Dok1 in a ubiquitin-proteasome-mediated mechanism. Together, these results suggest a novel mechanism of action of BRK in the promotion of tumor formation, which involves the targeting of tumor suppressor Dok1 for degradation through the ubiquitin proteasomal pathway.
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Affiliation(s)
- Sayem Miah
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Raghuveera Kumar Goel
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Chenlu Dai
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Natasha Kalra
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Erika Beaton-Brown
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Cancer Research Unit, Health Research Division, Saskatchewan Cancer Agency, and Division of Oncology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Edward T. Bagu
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Cancer Research Unit, Health Research Division, Saskatchewan Cancer Agency, and Division of Oncology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Keith Bonham
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Cancer Research Unit, Health Research Division, Saskatchewan Cancer Agency, and Division of Oncology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Kiven E. Lukong
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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17
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Suppression of KIF3B expression inhibits human hepatocellular carcinoma proliferation. Dig Dis Sci 2014; 59:795-806. [PMID: 24368420 PMCID: PMC3958719 DOI: 10.1007/s10620-013-2969-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 11/15/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND Human hepatocellular carcinoma (HCC) is one of the most common fatal cancers and an important health problem worldwide, but its mechanism is still unclear. Microtubule (MT) kinesin motor proteins orchestrate a variety of cellular processes (e.g. mitosis, motility and organelle transportation) and have been involved in human carcinogenesis. KIF3B, the kinesin superfamily of proteins (KIFs), plays an important role in the regulation of mitotic progression. AIM The expression of KIF3B and its involvement in HCC was investigated. METHODS Western blot and immunohistochemistry were used to measure the expression of KIF3B protein in HCC and adjacent non-tumorous tissues in 57 patients and Cell Counting Kit-8 to analyze the effects of growth and interference of KIF3B in the cell cycle process. RESULTS KIF3B protein level was increased in HCC tissues compared with the adjacent non-tumorous tissues. It was significantly associated with histological differentiation, tumor size, the level of alpha fetal protein (AFP) and proliferation marker Ki-67. Over-expression of KIF3B was correlated with poor survival. Following release of HepG2 cells from serum starvation, the expression of KIF3B was up-regulated. Furthermore, suppression of KIF3B not only decreased cancer cell growth but also induced apoptosis of cells. CONCLUSIONS Our results suggested that KIF3B expression was upregulated in HCC tumor tissues and proliferating HCC cells, and an increased KIF3B expression was associated with poor overall survival. KIF3B over-expression is involved in the pathogenesis of hepatocellular carcinoma and may serve as a potential therapeutic target for human HCC.
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18
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Nyamaa B, Kim HK, Jeong YJ, Song IS, Han J. Kinesin Spindle Protein Inhibition in Translational Research. J Lipid Atheroscler 2014. [DOI: 10.12997/jla.2014.3.2.63] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Bayalagmaa Nyamaa
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Department of Health Sciences and Technology, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea
| | - Hyoung Kyu Kim
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Department of Health Sciences and Technology, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea
| | - Yu Jeong Jeong
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Department of Health Sciences and Technology, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea
| | - In-Sung Song
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Department of Health Sciences and Technology, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea
| | - Jin Han
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Department of Health Sciences and Technology, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea
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19
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Liu LN, Huang PY, Lin ZR, Hu LJ, Liang JZ, Li MZ, Tang LQ, Zeng MS, Zhong Q, Zeng BH. Protein tyrosine kinase 6 is associated with nasopharyngeal carcinoma poor prognosis and metastasis. J Transl Med 2013; 11:140. [PMID: 23758975 PMCID: PMC3686693 DOI: 10.1186/1479-5876-11-140] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 06/03/2013] [Indexed: 12/16/2022] Open
Abstract
Background The aim of this study was to analyze the expression of protein tyrosine kinase 6 (PTK6) in nasopharyngeal carcinoma (NPC) samples, and to identify whether PTK6 can serve as a biomarker for the diagnosis and prognosis of NPC. Methods We used quantitative RT-PCR and Western blotting analysis to detect mRNA and protein expression of PTK6 in NPC cell lines and immortalized nasopharyngeal epithelial cell lines. 31 NPC and 16 non-tumorous nasopharyngeal mucosa biopsies were collected to detect the difference in the expression of mRNA level of PTK6 by quantitative RT-PCR. We also collected 178 NPC and 10 normal nasopharyngeal epithelial cases with clinical follow-up data to investigate the expression of PTK6 by immunohistochemistry staining (IHC). PTK6 overexpression on cell growth and colony formation ability were measured by the method of cell proliferation assay and colony formation assay. Results The expression of PTK6 was higher in most of NPC cell lines at both mRNA and protein levels than in immortalized nasopharyngeal epithelial cell lines (NPECs) induced by Bmi-1 (Bmi-1/NPEC1, and Bmi-1/NPEC2). The mRNA level of PTK6 was high in NPC biopsies compared to non-tumorous nasopharyngeal mucosa biopsies. IHC results showed the expression of PTK6 was significantly correlated to tumor size (P<0.001), clinical stage (P<0.001), and metastasis (P=0.016). The patients with high-expression of PTK6 had a significantly poor prognosis compared to those of low-expression (47.8% versus 80.0%, P<0.001), especially in the patients at the advanced stages (42.2% versus 79.1%, P<0.001). Multivariate analysis indicated that the level of PTK6 expression was an independent prognostic factor for the overall survival of patients with NPC (P <0.001). Overexpression of PTK6 in HNE1 cells enhanced the ability of cell proliferation and colony formation. Conclusions Our results suggest that high-expression of PTK6 is an independent factor for NPC patients and it might serve as a potential prognostic biomarker for patients with NPC.
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Affiliation(s)
- Li-na Liu
- Department of Oncology, Second Affiliated Hospital of Guangzhou medical college, 250 Changgang Road East, Guangzhou 510260, China
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20
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Scholey JM. Kinesin-2: a family of heterotrimeric and homodimeric motors with diverse intracellular transport functions. Annu Rev Cell Dev Biol 2013; 29:443-69. [PMID: 23750925 DOI: 10.1146/annurev-cellbio-101512-122335] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Kinesin-2 was first purified as a heterotrimeric, anterograde, microtubule-based motor consisting of two distinct kinesin-related subunits and a novel associated protein (KAP) that is currently best known for its role in intraflagellar transport and ciliogenesis. Subsequent work, however, has revealed diversity in the oligomeric state of different kinesin-2 motors owing to the combinatorial heterodimerization of its subunits and the coexistence of both heterotrimeric and homodimeric kinesin-2 motors in some cells. Although the functional significance of the homo- versus heteromeric organization of kinesin-2 motor subunits and the role of KAP remain uncertain, functional studies suggest that cooperation between different types of kinesin-2 motors or between kinesin-2 and a member of a different motor family can generate diverse patterns of anterograde intracellular transport. Moreover, despite being restricted to ciliated eukaryotes, kinesin-2 motors are now known to drive diverse transport events outside cilia. Here, I review the organization, assembly, phylogeny, biological functions, and motility mechanism of this diverse family of intracellular transport motors.
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Affiliation(s)
- Jonathan M Scholey
- Department of Molecular and Cell Biology, University of California, Davis, California 95616;
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21
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Liu X, Gong H, Huang K. Oncogenic role of kinesin proteins and targeting kinesin therapy. Cancer Sci 2013; 104:651-6. [PMID: 23438337 DOI: 10.1111/cas.12138] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 02/18/2013] [Accepted: 02/20/2013] [Indexed: 12/18/2022] Open
Abstract
The kinesin superfamily (KIF) is a group of proteins that share a highly conserved motor domain. Except for some members, many KIF proteins have adenosine triphosphatase activity and microtubule-dependent plus-end motion ability. Kinesins participate in several essential cellular functions, including mitosis, meiosis and the transport of macromolecules. Increasing evidence indicates kinesin proteins play critical roles in the genesis and development of human cancers. Some kinesin proteins are associated with maligancy as well as drug resistance of solid tumor. Thus, targeting KIF therapy seems to be a promising anticancer strategy. Inhibitors of KIF such as kinesin spindle protein (KSP/Eg5) have entered clinical trials for monotherapy or in combination with other drugs, and kinesins other than Eg5 with various potential anticancer target characteristics are also constantly being discovered and studied. Here, we summarize the oncogenic roles of kinesin proteins and potential cancer therapy strategies that target KIF.
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Affiliation(s)
- Xinran Liu
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, China
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22
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Locatelli A, Lofgren KA, Daniel AR, Castro NE, Lange CA. Mechanisms of HGF/Met signaling to Brk and Sam68 in breast cancer progression. Discov Oncol 2012; 3:14-25. [PMID: 22124844 DOI: 10.1007/s12672-011-0097-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Signal transduction pathways downstream of receptor tyrosine kinases (RTKs) are often deregulated during oncogenesis, tumor progression, and metastasis. In particular, the peptide growth factor hormone, hepatocyte growth factor (HGF), and its specific receptor, Met tyrosine kinase, regulate cancer cell migration, thereby conferring an aggressive phenotype (Nakamura et al., J Clin Invest 106(12):1511-1519, 2000; Huh et al., Proc Natl Acad Sci U S A 101:4477-4482, 2004). Additionally, overexpression of Met is associated with enhanced invasiveness of breast cancer cells (Edakuni et al., Pathol Int 51(3):172-178, 2001; Jin et al., Cancer 79(4):749-760, 1997; Tuck et al., Am J Pathol 148(1):225-232, 1996). Here, we review the regulation of recently identified novel downstream mediators of HGF/Met signaling, Breast tumor kinase (Brk/PTK6), and Src-associated substrate during mitosis of 68 kDa (Sam68), and discuss their relevance to mechanisms of breast cancer progression.
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Affiliation(s)
- Alessia Locatelli
- Department of Medicine, Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, 55455, USA
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23
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Telikicherla D, Maharudraiah J, Pawar H, Marimuthu A, Kashyap MK, Ramachandra YL, Roa JC, Pandey A. Overexpression of Kinesin Associated Protein 3 (KIFAP3) in Breast Cancer. JOURNAL OF PROTEOMICS & BIOINFORMATICS 2012; 5:122-126. [PMID: 26843789 PMCID: PMC4734396 DOI: 10.4172/jpb.1000223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Gene expression profiling studies on breast cancer have generated catalogs of differentially expressed genes. However, many of these genes have not been investigated for their expression at the protein level. It is possible to systematically evaluate such genes in a high-throughput fashion for their overexpression at the protein level using breast cancer tissue microarrays. Our strategy involved integration of information from publicly available repositories of gene expression to prepare a list of genes upregulated at the mRNA level in breast cancer followed by curation of the published literature to identify those genes that were not tested for overexpression at the protein level. We identified Kinesin Associated Protein 3 (KIFAP3) as one such molecule for further validation at the protein level. Immunohistochemical labeling of KIFAP3 using breast cancer tissue microarrays revealed overexpression of KIFAP3 protein in 84% (240/285) of breast cancers indicating the utility of our integrated approach of combining computational analysis with experimental biology.
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Affiliation(s)
- Deepthi Telikicherla
- Institute of Bioinformatics, International Tech Park, Bangalore-560 066, India
- Department of Biotechnology, Kuvempu University, Shankaraghatta-577451, India
| | - Jagadeesha Maharudraiah
- Institute of Bioinformatics, International Tech Park, Bangalore-560 066, India
- Department of Pathology, Raja Rajeshwari Medical College and Hospital, Bangalore-560074, India
- Manipal University, Madhav Nagar, Manipal-576104, India
| | - Harsh Pawar
- Institute of Bioinformatics, International Tech Park, Bangalore-560 066, India
- Rajiv Gandhi University of Health Sciences, Bangalore-560041, India
- Department of Pathology, Kidwai Memorial Institute of Oncology, Bangalore-560029, India
| | | | - Manoj Kumar Kashyap
- Institute of Bioinformatics, International Tech Park, Bangalore-560 066, India
| | - Y. L. Ramachandra
- Department of Biotechnology, Kuvempu University, Shankaraghatta-577451, India
| | - Juan Carlos Roa
- Department of Pathology, Universidad de La Frontera, Temuco, Chile
| | - Akhilesh Pandey
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Departments of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Corresponding author: Akhilesh Pandey M.D., Ph.D., McKusick-Nathans Institute of Genetic Medicine, 733 N. Broadway, BRB 527, Johns Hopkins University, Baltimore, MD 21205, USA, Tel: 410-502-6662; Fax: 410-502-7544;
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Zeng H, Belanger DB, Curran PJ, Shipps GW, Miao H, Bracken JB, Arshad Siddiqui M, Malkowski M, Wang Y. Discovery of novel imidazo[1,2-a]pyrazin-8-amines as Brk/PTK6 inhibitors. Bioorg Med Chem Lett 2011; 21:5870-5. [PMID: 21855335 DOI: 10.1016/j.bmcl.2011.07.101] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 07/25/2011] [Accepted: 07/26/2011] [Indexed: 01/05/2023]
Abstract
A series of substituted imidazo[1,2-a]pyrazin-8-amines were discovered as novel breast tumor kinase (Brk)/protein tyrosine kinase 6 (PTK6) inhibitors. Tool compounds with low-nanomolar Brk inhibition activity, high selectivity towards other kinases and desirable DMPK properties were achieved to enable the exploration of Brk as an oncology target.
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Affiliation(s)
- Hongbo Zeng
- Department of Chemistry, Merck Research Laboratories, 320 Bent Street, Cambridge, MA 02141, United States.
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25
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Fan C, Zhao Y, Liu D, Zhang X, Wang E. Detection of Brk expression in non-small cell lung cancer: clinicopathological relevance. Tumour Biol 2011; 32:873-80. [PMID: 21603980 DOI: 10.1007/s13277-011-0188-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 04/29/2011] [Indexed: 01/20/2023] Open
Abstract
Breast tumor kinase (Brk), also known as protein tyrosine kinase 6, is a nonreceptor tyrosine kinase containing SH3, SH2, and tyrosine kinase catalytic domains. Brk upregulation and oncogenic properties have been found in several malignant tumors, including breast, colon carcinomas, and melanomas, but the expression of Brk and its clinical significance in non-small cell lung cancer (NSCLC) remains unclear. In the current study, we examined the expression of Brk and its correlation with clinicopathological features involving p53, ki67, and E-cadherin status in NSCLC tissue using immunohistochemistry. We also used immunocytochemistry and immunofluorescent staining to examine the Brk expression and its subcellular localization in NSCLC cell lines, including LTE and H460. We further confirmed cytoplasmic and nucleus expression of Brk in LTE and H460 cells using Western blotting. The Brk expression in NSCLC cells was mainly found in cytoplasm (59/122, 48.4%) with some nucleus staining (17/122, 13.9%) with a total positive rate of 53.3% (65/122). Cytoplasmic Brk expression in NSCLC was higher than that in normal lung tissues (24/122, 19.7%) (P < 0.05). Increased cytoplasmic Brk expression in NSCLC was associated with large tumor size (≥ 3 cm), lymph node metastasis, and advanced tumor-node-metastasis (TNM) stages (III and IV) (P < 0.05). Moreover, increased cytoplasmic Brk expression was positively associated with Ki67 status in NSCLC (P < 0.05). Reduced E-cadherin expression was also found to be associated with lymph node metastasis and advanced TNM stages (III and IV) in NSCLC (P < 0.05). Brk expression was not associated with E-cadherin expression and P53 status in NSCLC (P > 0.05). The present findings indicate an increase of cytoplasmic Brk expression in NSCLC which may play a role in tumor development, including tumor expansion and lymph node metastasis in which Ki67, but not E-cadherin, and P53 status may be involved.
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Affiliation(s)
- Chuifeng Fan
- Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University, 110001, Shenyang, China.
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26
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Yu Y, Feng YM. The role of kinesin family proteins in tumorigenesis and progression: potential biomarkers and molecular targets for cancer therapy. Cancer 2011; 116:5150-60. [PMID: 20661912 DOI: 10.1002/cncr.25461] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The kinesin superfamily contains a conserved class of microtubule-dependent molecular motor proteins that possess an adenosine triphosphatase activity and motion characteristics. The active movement of kinesins supports several cellular functions, including mitosis, meiosis, and the transport of macromolecules. Mitosis is a process of eukaryotic cell division that involves the division of nuclei, cytoplasm, organelles, and the cell membrane into 2 daughter cells with roughly equivalent portions of these cellular components. Any errors in this process could result in cell death, abnormality (such as gene deletion, chromosome translocation, or duplication), and cancer. Because mitosis is complex and highly regulated, alteration of kinesin expression or function could lead to carcinogenesis. Moreover, because human cancer is a gene-related disease involving abnormal cell growth, targeting kinesins may create a novel strategy for the control of human cancer. Indeed, several such drugs are being tested successfully in the clinic. In this review, the authors discuss in detail the structure and function of kinesins, the correlation of kinesin expression with tumorigenesis and progression, and the development of biomarkers and cancer-targeted therapy involving the kinesin family proteins.
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Affiliation(s)
- Yue Yu
- Department of Biochemistry and Molecular Biology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
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27
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Ostrander JH, Daniel AR, Lange CA. Brk/PTK6 signaling in normal and cancer cell models. Curr Opin Pharmacol 2010; 10:662-9. [PMID: 20832360 DOI: 10.1016/j.coph.2010.08.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 08/10/2010] [Accepted: 08/10/2010] [Indexed: 01/08/2023]
Abstract
Breast tumor kinase (Brk), also termed PTK6, is known to function in cell-type and context-dependent processes governing normal differentiation. However, in tumors in which Brk is overexpressed, this unusual soluble tyrosine kinase is emerging as a mediator of cancer cell phenotypes, including increased proliferation, survival, and migration. Nuclear and cytoplasmic substrates phosphorylated by Brk include a collection of regulatory RNA-binding proteins, adaptor molecules that link Brk to signaling pathways generally associated with the activation of growth factor receptors, and Signal Transducers and Activators of Transcription (STAT) molecules that are direct regulators of gene expression. Understanding Brk-dependent regulation of these key signaling pathways and how they influence cancer cell behavior is predicted to inform the development of improved 'targeted' cancer therapies and may provide insight into ways to avoid chemo-resistance to established treatments.
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Affiliation(s)
- Julie H Ostrander
- Department of Medicine, Division of Medical Oncology, Duke University Medical Center, Durham, NC 27710, USA
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Castro NE, Lange CA. Breast tumor kinase and extracellular signal-regulated kinase 5 mediate Met receptor signaling to cell migration in breast cancer cells. Breast Cancer Res 2010; 12:R60. [PMID: 20687930 PMCID: PMC2949652 DOI: 10.1186/bcr2622] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 07/02/2010] [Accepted: 08/05/2010] [Indexed: 02/06/2023] Open
Abstract
Introduction Breast tumor kinase (Brk/protein tyrosine kinase 6 (PTK6)) is a nonreceptor, soluble tyrosine kinase overexpressed in the majority of breast tumors. Previous work has placed Brk downstream of epidermal growth factor receptor (ErbB) activation and upstream of extracellular signal-regulated kinase 5 (ERK5) and p38 mitogen-activated protein (MAP) kinases. Herein we investigate the regulation of Brk kinase activity and cell migration in response to treatment of keratinocytes (HaCaT cells) and breast cancer cell lines (MDA-MB-231 and T47D cells) with hepatocyte growth factor (HGF) and macrophage stimulating protein (MSP), peptide ligands for Met and Ron receptors, respectively. Methods In vitro kinase assays were performed to directly measure Brk kinase activity in response to MET and RON ligands. Transfection of Brk-targeted RNAi was used to knock down endogenous Brk or ERK5 in multiple cell lines. Kinase activities (downstream of MET signaling) were assayed by Western blotting using total and phospho-specific antibodies. Boyden chamber assays were used to measure cell migration in response to manipulation of Brk and downstream MET effectors. Rescue experiments were performed by knock down of endogenous Brk using RNAi (targeting the untranslated region (3′-UTR)) and transient transfection (re-expression) of either wild-type or kinase-inactive Brk. Results Brk gene silencing revealed that HGF, but not MSP, induced robust Brk-dependent cell migration. Brk and ERK5 copurified in HGF-induced protein complexes, and Brk/ERK5 complexes formed independently of Brk kinase activity. ERK5 was required for breast cancer cell but not keratinocyte cell migration, which became ERK1/2-dependent upon ERK5 knockdown. Notably, rescue experiments indicated that the kinase activity of Brk was not required for HGF-induced cell migration. Further, expression of either wild-type or kinase-inactive Brk in Brk-null MDA-MB-435 cells activated ERK5 and conferred increased HGF-induced cell migration. Conclusions These results have identified Brk and ERK5 as important downstream effectors of Met signaling to cell migration. Targeting ERK5 kinase activity or inhibiting the formation of Brk/ERK5 complexes may provide an additional means of blocking cell migration associated with breast cancer progression to metastasis.
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Affiliation(s)
- Nancy E Castro
- Department of Pharmacology, University of Minnesota, 321 Church Street S.E., Minneapolis, MN 55455, USA
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Kang SA, Lee ES, Yoon HY, Randazzo PA, Lee ST. PTK6 inhibits down-regulation of EGF receptor through phosphorylation of ARAP1. J Biol Chem 2010; 285:26013-21. [PMID: 20554524 DOI: 10.1074/jbc.m109.088971] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PTK6 (also known as Brk) is a non-receptor-tyrosine kinase containing SH3, SH2, and catalytic domains, that is expressed in more than 60% of breast carcinomas but not in normal mammary tissues. To analyze PTK6-interacting proteins, we have expressed Flag-tagged PTK6 in HEK293 cells and performed co-immunoprecipitation assays with Flag antibody-conjugated agarose. A 164-kDa protein in the precipitated fraction was identified as ARAP1 (also known as centaurin delta-2) by MALDI-TOF mass analysis. ARAP1 associated with PTK6 in an EGF/EGF receptor (EGFR)-dependent manner. In addition, the SH2 domain of PTK6, particularly the Arg(105) residue that contacts the phosphate group of the tyrosine residue, was essential for the association. Moreover, PTK6 phosphorylated residue Tyr(231) in the N-terminal domain of ARAP1. Expression of ARAP1, but not of the Y231F mutant, inhibited the down-regulation of EGFR in HEK293 cells expressing PTK6. Silencing of endogenous PTK6 expression in breast carcinoma cells decreased EGFR levels. These results demonstrate that PTK6 enhances EGFR signaling by inhibition of EGFR down-regulation through phosphorylation of ARAP1 in breast cancer cells.
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Affiliation(s)
- Shin-Ae Kang
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
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Brauer PM, Tyner AL. Building a better understanding of the intracellular tyrosine kinase PTK6 - BRK by BRK. Biochim Biophys Acta Rev Cancer 2010; 1806:66-73. [PMID: 20193745 DOI: 10.1016/j.bbcan.2010.02.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 02/17/2010] [Accepted: 02/19/2010] [Indexed: 01/21/2023]
Abstract
Protein tyrosine kinase 6 (PTK6), also referred to as breast tumor kinase BRK, is a member of a distinct family of kinases that is evolutionarily related to the SRC family of tyrosine kinases. While not expressed in the normal mammary gland, PTK6 expression is detected in a large proportion of human mammary gland tumors. In breast tumor cells, PTK6 promotes growth factor signaling and cell migration. PTK6 expression is also increased in a number of other epithelial tumors, including ovarian and colon cancer. In contrast, PTK6 is expressed in diverse normal epithelia, including the linings of the gastrointestinal tract, skin and prostate, where its expression correlates with cell cycle exit and differentiation. Disruption of the mouse Ptk6 gene leads to increased growth and impaired differentiation in the small intestine that is accompanied by increased AKT and Wnt signaling. Following total body irradiation, PTK6 expression is induced in proliferating progenitor cells of the intestine, where it plays an essential role in DNA-damage induced apoptosis. A distinguishing feature of PTK6 is its flexibility in intracellular localization, due to a lack of amino-terminal myristoylation/palmitoylation. Recently a number of substrates of PTK6 have been identified, including nuclear RNA-binding proteins and transcription factors. We discuss PTK6 signaling, its apparent conflicting roles in cancer and normal epithelia, and its potential as a therapeutic target in epithelial cancers.
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Affiliation(s)
- Patrick M Brauer
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA
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Doodhi H, Ghosal D, Krishnamurthy M, Jana SC, Shamala D, Bhaduri A, Sowdhamini R, Ray K. KAP, the accessory subunit of kinesin-2, binds the predicted coiled-coil stalk of the motor subunits. Biochemistry 2009; 48:2248-60. [PMID: 19161286 DOI: 10.1021/bi8018338] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Kinesin-2 is an anterograde motor involved in intraflagellar transport and certain other intracellular transport processes. It consists of two different motor subunits and an accessory protein KAP (kinesin accessory protein). The motor subunits were shown to bind each other through the coiled-coil stalk domains, while KAP was proposed to bind the tail domains of the motor subunits. Although several genetic studies established that KAP plays an important role in kinesin-2 functions, its exact role remains unclear. Here, we report the results of a systematic analysis of the KAP binding sites by using recombinant Drosophila kinesin-2 subunits as well as the endogenous proteins. These show that at least one of the coiled-coil stalks is sufficient to bind the N-terminal region of DmKAP. The soluble complex involving the recombinant kinesin-2 fragments is reconstituted in vitro at high salt concentrations, suggesting that the interaction is primarily nonionic. Furthermore, independent distant homology modeling indicated that DmKAP may bind along the coiled-coil stalks through a combination of predominantly hydrophobic interactions and hydrogen bonds. These observations led us to propose that KAP would stabilize the motor subunit heterodimer and help assemble a greater kinesin-2 complex in vivo.
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Affiliation(s)
- Harinath Doodhi
- Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
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Lukong KE, Huot MÉ, Richard S. BRK phosphorylates PSF promoting its cytoplasmic localization and cell cycle arrest. Cell Signal 2009; 21:1415-22. [DOI: 10.1016/j.cellsig.2009.04.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Accepted: 04/30/2009] [Indexed: 11/29/2022]
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Rotureau B, Morales MA, Bastin P, Späth GF. The flagellum-mitogen-activated protein kinase connection in Trypanosomatids: a key sensory role in parasite signalling and development? Cell Microbiol 2009; 11:710-8. [DOI: 10.1111/j.1462-5822.2009.01295.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Sam68 (Src-associated in mitosis, 68 kDa) is a KH domain RNA binding protein implicated in a variety of cellular processes, including alternative pre-mRNA splicing, but its functions are not well understood. Using RNA interference knockdown of Sam68 expression and splicing-sensitive microarrays, we identified a set of alternative exons whose splicing depends on Sam68. Detailed analysis of one newly identified target exon in epsilon sarcoglycan (Sgce) showed that both RNA elements distributed across the adjacent introns and the RNA binding activity of Sam68 are necessary to repress the Sgce exon. Sam68 protein is upregulated upon neuronal differentiation of P19 cells, and many Sam68 RNA targets change in expression and splicing during this process. When Sam68 is knocked down by short hairpin RNAs, many Sam68-dependent splicing changes do not occur and P19 cells fail to differentiate. We also found that the differentiation of primary neuronal progenitor cells from embryonic mouse neocortex is suppressed by Sam68 depletion and promoted by Sam68 overexpression. Thus, Sam68 controls neurogenesis through its effects on a specific set of RNA targets.
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Zhang X, Gao F, Yu LL, Peng Y, Liu HH, Liu JY, Yin M, Ni J. Dual functions of a monoclonal antibody against cell surface F1F0 ATP synthase on both HUVEC and tumor cells. Acta Pharmacol Sin 2008; 29:942-50. [PMID: 18664327 DOI: 10.1111/j.1745-7254.2008.00830.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
AIM To generate a monoclonal antibody (McAb) against cell surface F1F0 ATP synthase (ATPase) and observe its antitumoral activity on both human umbilical vein endothelial cells (HUVEC) and tumor cells. METHODS Hybridoma cells secreting McAb against ATPase were produced by polyethylene glycol-mediated fusions and screened by ELISA. The specificity of McAb was demonstrated by immunofluorescence and confocal imaging, as well as flow cytometry analysis. After the blockade of surface ATPase with McAb on HUVEC and human breast adenocarcinoma MDA-MB-231 cells, an ATP determination kit and CellTiter96 AQueous Assay (MTS) assay were used to detect the effect of the antibody on extracellular ATP modification and cell proliferation. A cellular cytotoxicity assay in combination with doxorubicin, and a cell migration assay on MDA-MB-231 cells were used to determine the antitumoral activity. Finally, a HUVEC tube formation assay was used to detect the antiangiogenic effect of McAb178-5G10. RESULTS A monoclonal antibody (McAb178-5G10) against the beta-subunit of ATPase was generated, and its reactivity toward HUVEC and tumor cells was studied. We demonstrate that McAb178-5G10 binds to ATPase at the cell surface, where it is able to inhibit ATP synthesis. This antibody also prevents the proliferation of HUVEC and MDA-MB-231 cells. Furthermore, McAb178-5G10 enhances the tumoricidal effects of doxorubicin (P<0.05), inhibits the migration of MDA-MB- 231 in transwell assays (P<0.01), and disrupts HUVEC tube formation on Matrigel (P<0.01). CONCLUSION McAb178-5G10 binds preferentially to cell surface ATPase, blocks ATP synthesis, and exhibits both antiangiogenic and antitumorigenic effects.
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Affiliation(s)
- Xia Zhang
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China
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