Tang H.,Central South University |
Tang H.,The Center for Skull Base Surgery and Neurooncology |
Tang H.,Sun Yat Sen University |
Wang Z.,Central South University |
And 7 more authors.
Current Cancer Drug Targets | Year: 2012
Leucine-rich repeat (LRR) genes encode transmembrane proteins that are essential for normal brain development and are often dysregulated in central nervous system tumors. Leucine-rich repeat C4 (LRRC4) is a member of the LRR protein superfamily and specifically expressed in brain tissue. Importantly it acts as a tumor suppressor in the pathogenesis of malignant gliomas. However, the molecular mechanisms by which LRRC4 regulates glioma tumorigenesis are largely unknown. In this report, we found that miR-185 is markedly upregulated by LRRC4. We also found that miR-185 was downregulated in glioma, and overexpression of miR-185 inhibited glioma cell invasion. Low expressions of LRRC4 and miR-185 were associated with a poor outcome in glioma patients. Further investigation revealed that LRRC4 mediated its tumor suppressor function by regulating miR-185 targets CDC42 and RhoA. LRRC4 overexpression inhibited glioma cell invasion through miR-185-mediated CDC42 and RhoA direct regulation and VEGFA indirect regulation. Together, our findings suggest that the altered expression of the tumor suppressor LRRC4 may be an important event that leads to the dysregulation of miR-185 in human gliomas. LRRC4 and miR-185 may also be good prognostic markers and therapeutic targets in glioma. © 2012 Bentham Science Publishers.
Ye F.,Sun Yat Sen University |
Tang H.,Sun Yat Sen University |
Liu Q.,The Center for Skull Base Surgery and Neurooncology |
Xie X.,Sun Yat Sen University |
And 3 more authors.
Journal of Translational Medicine | Year: 2014
Background: miR-200b has been reported to be a tumor suppressor and a promising therapeutic target in cancer. miR-200b has been associated with epithelial-mesenchymal transition and chemo-resistance in cancer. The aim of this study is to investigate the expression of miR-200b, its prognostic roles and its potential targets in breast cancer.Methods: qRT-PCR was used to detect miR-200b expression in breast cancer tissues and cell lines. In situ hybridization of miR-200b on tissue microarray including 134 breast cancer samples was used to evaluate its prognostic role. Novel targets of miR-200b in breast cancer were predicted and confirmed by luciferase reporter assay and western bloting. Immunohistochemical staining was used for protein detection. The biological effects of miR-200b in breast cancer cells were further confirmed by ectopic expression of its mimics followed by MTT assay and invasion test.Results: miR-200b was downregulated in breast cancer tissues and cell lines and its low-expression correlated with poor outcome in breast cancer patients. Members of RAB family, RAB21, RAB23, RAB18 and RAB3B were predicted to be the targets of miR-200b. The luciferase reporter assay was performed to certificate this prediction. The expressions of RAB21, RAB23, RAB18 and RAB3B were suppressed by transfection of miR-200b in breast cancer cells. Over-expression of miR-200b or knock-down of RAB21, RAB23, RAB18 and RAB3B inhibited breast cancer cell proliferation and invasion in vitro.Conclusions: Our study provides evidence that miR-200b is a prognostic factor in breast cancer targeting multiple members of RAB family. MiR-200b could be a potential therapeutic target in breast cancer. © 2014 Ye et al.; licensee BioMed Central Ltd.