Project description:MicroRNAs (miRNAs) have important roles in gene regulation. Dysregulation of miRNAs has been associated with tumorigenesis. Recent studies suggest miR-193b is a tumor suppressor gene. In a previous study, we reported that miR-193b represses cell proliferation and regulates cyclin D1 (CCND1) in melanoma. Now we demonstrate that miR-193b regulates myeloid cell leukemia sequence 1 (Mcl-1) in melanoma cells. miRNA microarray profiling revealed the miR-193b level in malignant melanomas was significantly downregulated compared to benign nevi, while a tissue microarray demonstrated overexpression of Mcl-1 in malignant melanoma. The Mcl-1 expressions were inversely correlated with the miR-193b levels in melanoma tissue samples, suggesting a potential regulatory role of miR-193b. Overexpression of miR-193b repressed Mcl-1 in melanoma cell lines. It is well known that Mcl-1 knockdown confers cell sensitivity to ABT-737, a small molecular inhibitor of Bcl-2, Bcl-XL and Bcl-w. We found miR-193b, through repressing Mcl-1 expression, could also sensitize melanoma cells that were refractory to ABT-737. Furthermore, miR-193b directly regulates Mcl-1 by targeting the 3’ untranslated region (3’UTR) of Mcl-1 mRNA. Interestingly, miR-193b may recognize sequences on the 3’UTR that do not base pair with its seed region. In conclusion, our study suggests the downregulation of miR-193b could be an early event during melanoma progression, and demonstrates miR-193b directly regulates Mcl-1 by targeting both seed and seedless sequences of the 3’ UTR.
Project description:MicroRNAs (miRNAs) have important roles in gene regulation. Dysregulation of miRNAs has been associated with tumorigenesis. Recent studies suggest miR-193b is a tumor suppressor gene. In a previous study, we reported that miR-193b represses cell proliferation and regulates cyclin D1 (CCND1) in melanoma. Now we demonstrate that miR-193b regulates myeloid cell leukemia sequence 1 (Mcl-1) in melanoma cells. miRNA microarray profiling revealed the miR-193b level in malignant melanomas was significantly downregulated compared to benign nevi, while a tissue microarray demonstrated overexpression of Mcl-1 in malignant melanoma. The Mcl-1 expressions were inversely correlated with the miR-193b levels in melanoma tissue samples, suggesting a potential regulatory role of miR-193b. Overexpression of miR-193b repressed Mcl-1 in melanoma cell lines. It is well known that Mcl-1 knockdown confers cell sensitivity to ABT-737, a small molecular inhibitor of Bcl-2, Bcl-XL and Bcl-w. We found miR-193b, through repressing Mcl-1 expression, could also sensitize melanoma cells that were refractory to ABT-737. Furthermore, miR-193b directly regulates Mcl-1 by targeting the 3â untranslated region (3âUTR) of Mcl-1 mRNA. Interestingly, miR-193b may recognize sequences on the 3âUTR that do not base pair with its seed region. In conclusion, our study suggests the downregulation of miR-193b could be an early event during melanoma progression, and demonstrates miR-193b directly regulates Mcl-1 by targeting both seed and seedless sequences of the 3â UTR. 15 primary melanoma samples, 8 metastatic melanomas and 8 benign nevi samples were profiled on Agilent miRNA array platform
Project description:This SuperSeries is composed of the following subset Series: GSE18509: miR-193b represses cell proliferation and regulates cyclin D1 in melanoma: benign nevi and metastatic melanoma GSE18510: miR-193b represses cell proliferation and regulates cyclin D1 in melanoma: Malme-3M Refer to individual Series
Project description:Cutaneous melanoma is an increasingly common form of skin cancer. The molecular mechanisms regulating melanoma progression are not completely understood. We speculated that specific miRNAs may be involved in melanoma development. We compared the miRNA expression profiles of benign nevi and metastatic melanomas. Unsupervised hierarchical clustering demonstrated a distinct miRNA expression pattern in metastatic melanomas compared to nevi. We identified miRNAs that were differentially expressed in melanoma. Notably, miR-193b was significantly down-regulated in the melanoma tissue examined. Using functional studies we demonstrated that over-expression of miR-193b significantly reduced melanoma cell proliferation, and arrested cell at G1 phase. Further gene expression analysis revealed that miR-193b regulated targets involved in cell cycle. Cyclin D1 was down-regulated by miR-193b at both the mRNA and protein level. This is the first study to show that the miR-193b may reduce cell proliferation by directly repressing cyclin D1. Overall, our study suggests that miRNAs are dysregulated in metastatic melanoma, and that miR-193b may play an important role in melanoma.
Project description:Cutaneous melanoma is an increasingly common form of skin cancer. The molecular mechanisms regulating melanoma progression are not completely understood. We speculated that specific miRNAs may be involved in melanoma development. We compared the miRNA expression profiles of benign nevi and metastatic melanomas. Unsupervised hierarchical clustering demonstrated a distinct miRNA expression pattern in metastatic melanomas compared to nevi. We identified miRNAs that were differentially expressed in melanoma. Notably, miR-193b was significantly down-regulated in the melanoma tissue examined. Using functional studies we demonstrated that over-expression of miR-193b significantly reduced melanoma cell proliferation, and arrested cell at G1 phase. Further gene expression analysis revealed that miR-193b regulated targets involved in cell cycle. Cyclin D1 was down-regulated by miR-193b at both the mRNA and protein level. This is the first study to show that the miR-193b may reduce cell proliferation by directly repressing cyclin D1. Overall, our study suggests that miRNAs are dysregulated in metastatic melanoma, and that miR-193b may play an important role in melanoma. 8 benign nevi and 8 metastatic melanoma tissue samples were profiled by Agilent MicroRNA Microarray (V1.5).
Project description:Cutaneous melanoma is an increasingly common form of skin cancer. The molecular mechanisms regulating melanoma progression are not completely understood. We speculated that specific miRNAs may be involved in melanoma development. We compared the miRNA expression profiles of benign nevi and metastatic melanomas. Unsupervised hierarchical clustering demonstrated a distinct miRNA expression pattern in metastatic melanomas compared to nevi. We identified miRNAs that were differentially expressed in melanoma. Notably, miR-193b was significantly down-regulated in the melanoma tissue examined. Using functional studies we demonstrated that over-expression of miR-193b significantly reduced melanoma cell proliferation, and arrested cell at G1 phase. Further gene expression analysis revealed that miR-193b regulated targets involved in cell cycle. Cyclin D1 was down-regulated by miR-193b at both the mRNA and protein level. This is the first study to show that the miR-193b may reduce cell proliferation by directly repressing cyclin D1. Overall, our study suggests that miRNAs are dysregulated in metastatic melanoma, and that miR-193b may play an important role in melanoma.
2009-12-20 | GSE18510 | GEO
Project description:miR-193b represses cell proliferation and regulates cyclin D1 in melanoma