RESUMO
Cell plasticity regulated by the balance between the mesenchymal to epithelial transition (MET) and the opposite program, EMT, is critical in the metastatic cascade. Several transcription factors (TFs) are known to regulate EMT, though the mechanisms of MET remain unclear. We demonstrate a novel function of two TFs, OVOL1 and OVOL2, as critical inducers of MET in human cancers. Our findings indicate that the OVOL-TFs control MET through a regulatory feedback loop with EMT-inducing TF ZEB1, and the regulation of mRNA splicing by inducing Epithelial Splicing Regulatory Protein 1 (ESRP1). Using mouse prostate tumor models we show that expression of OVOL-TFs in mesenchymal prostate cancer cells attenuates their metastatic potential. The role of OVOL-TFs as inducers of MET is further supported by expression analyses in 917 cancer cell lines, suggesting their role as crucial regulators of epithelial-mesenchymal cell plasticity in cancer.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Transição Epitelial-Mesenquimal , Neoplasias/metabolismo , Neoplasias/patologia , Fatores de Transcrição/metabolismo , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Análise por Conglomerados , Técnicas de Cocultura , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Xenoenxertos , Humanos , Macrófagos/metabolismo , Masculino , Camundongos , Invasividade Neoplásica , Metástase Neoplásica , Neoplasias/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Splicing de RNA , Transcrição GênicaRESUMO
Disseminated tumor cells (DTCs) are believed to lie dormant in the marrow before they can be activated to form metastases. How DTCs become dormant in the marrow and how dormant DTCs escape dormancy remains unclear. Recent work has shown that prostate cancer (PCa) cell lines express the growth-arrest specific 6 (GAS6) receptors Axl, Tyro3, and Mer, and become growth arrested in response to GAS6. We therefore hypothesized that GAS6 signaling regulates the proliferative activity of DTCs in the marrow. To explore this possibility, in vivo studies were performed where it was observed that when Tyro3 expression levels exceed Axl expression, the PCa cells exhibit rapid growth. When when Axl levels predominate, PCa cells remain largely quiescent. These findings suggest that a balance between the expression of Axl and Tyro3 is associated with a molecular switch between a dormant and a proliferative phenotype in PCa metastases.
Assuntos
Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/secundário , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Animais , Neoplasias Ósseas/genética , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Camundongos , Modelos Biológicos , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Neoplasias da Próstata/genética , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Receptor Tirosina Quinase AxlRESUMO
Transcriptional repressors and corepressors play a critical role in cellular homeostasis and are frequently altered in cancer. C-terminal binding protein 1 (CtBP1), a transcriptional corepressor that regulates the expression of tumor suppressors and genes involved in cell death, is known to play a role in multiple cancers. In this study, we observed the overexpression and mislocalization of CtBP1 in metastatic prostate cancer and demonstrated the functional significance of CtBP1 in prostate cancer progression. Transient and stable knockdown of CtBP1 in prostate cancer cells inhibited their proliferation and invasion. Expression profiling studies of prostate cancer cell lines revealed that multiple tumor suppressor genes are repressed by CtBP1. Furthermore, our studies indicate a role for CtBP1 in conferring radiation resistance to prostate cancer cell lines. In vivo studies using chicken chorioallantoic membrane assay, xenograft studies, and murine metastasis models suggested a role for CtBP1 in prostate tumor growth and metastasis. Taken together, our studies demonstrated that dysregulated expression of CtBP1 plays an important role in prostate cancer progression and may serve as a viable therapeutic target.
