MiR-92a regulates oral squamous cell carcinoma (OSCC) cell growth by targeting FOXP1 expression.

Increasing evidence indicates that microRNAs dysregulation contributes to the development and progression of various human cancers, including oral squamous cell carcinoma (OSCC). However, little is known about the potential role of microRNA-92a (miR-92a) in OSCC. Thus, the aim of this study was to investigate the effects of miR-92a expression on OSCC cell growth, apoptosis and tumorigenesis. Real-time quantitative polymerase chain reaction was used to detect the expression level of miR-92a in primary tumor tissues and OSCC cell lines. The effects of miR-92a on cell proliferation, cell cycle, apoptosis and tumorigenesis of OSCC cells were explored after miR-92a expression was increased or decreased in the UM1 and Tca-8113 cells, respectively. The 3'-untranslated region (3'-UTR) of FOXP1 combined with miR-92a was analyzed with dual-luciferase reporter assays. The level of miR-92a expression was significantly up-regulated in the OSCC tissues and cell lines. The up-regulation of miR-92a expression promoted UM1 cell proliferation, cell cycle progression in vitro and tumor growth in nude mice, but its expression reduction inhibited these processes and induced apoptosis in Tca-8113 cells. Additionally, miR-92a expression was inversely correlated with FOXP1 protein expression in the OSCC tissues and cell lines. Furthermore, FOXP1 was identified as a functional downstream target of miR-92a by directly targeting the 3'-UTR of FOXP1. These findings indicate that miR-92a may act as a tumor inducer in OSCC by suppressing FOXP1 expression, and it could serve as a potential therapeutic target for OSCC treatment.

Guo J ，Wen N ，Yang S ，Guan X ，Cang S ... -  《-》

Connective tissue growth factor modulates oral squamous cell carcinoma invasion by activating a miR-504/FOXP1 signalling.

Yang MH ，Lin BR ，Chang CH ，Chen ST ，Lin SK ，Kuo MY ，Jeng YM ，Kuo ML ，Chang CC ... -  《-》

Long non-coding RNA CCAT1 is a prognostic biomarker for the progression of oral squamous cell carcinoma via miR-181a-mediated Wnt/β-catenin signaling pathway.

Li GH ，Ma ZH ，Wang X 《-》

MicroRNA-16 functions as a tumor-suppressor gene in oral squamous cell carcinoma by targeting AKT3 and BCL2L2.

Aberrant expressions of microRNAs have been reported to be strongly associated with the progression and prognosis of various tumors, including oral squamous cell carcinoma (OSCC). Recent studies on miRNA expression profiling have suggested that microRNA-16 (miR-16) may be dysregulated in OSCC. However, the tumorigenic roles and mechanisms of miR-16 in OSCC are still largely unknown. In this study, we demonstrated that miR-16 was specifically downregulated in both OSCC patients and cancer cell lines. In addition, functional roles of miR-16 in vitro suggested that the miR-16 mimic inhibited cell proliferation and induced apoptosis, whereas miR-16 inhibitor displayed the opposite effects. Luciferase reporter assay and correlation analysis showed that AKT3 and BCL2L2 were directly targeted by miR-16 and were inversely expressed with miR-16 in OSCC. Moreover, restoration of AKT3 and BCL2L2 expression could partially reverse the cell proliferation inhibition and apoptosis induction caused by miR-16. In xenograft nude mice, miR-16 mimics decreased the expression of AKT3 and BCL2L2 and reduced the tumors volumes and weights, whereas the miR-16 inhibitor exhibited adverse effects in the derived xenografts. In conclusion, the findings suggested that miR-16 functions as a tumor suppressor miRNA to inhibit cell proliferation and induce apoptosis in OSCC through decreasing the oncogenes AKT3 and BCL2L2 and that miR-16 could be a potential therapeutic target for OSCC.

Wang X ，Li GH 《-》

MicroRNA-375 Inhibits Growth and Enhances Radiosensitivity in Oral Squamous Cell Carcinoma by Targeting Insulin Like Growth Factor 1 Receptor.

MicroRNAs (miRNAs) have emerged as key players in various human biological processes, including tumorigenesis. Here, we investigated the roles of miR-375 in the pathogenesis of oral squamous cell carcinoma (OSCC). We performed quantitative real-time PCR (qRT-PCR) to detect miR-375 expression in OSCC tissues and corresponding normal oral epithelial tissues and analyze the correlation of miR-375 expression with OSCC metastasis and patient's survival. Then, the effects of miR-375 expression on proliferation, cell cycle, apoptosis and radiosensitivity in OSCC cells were determined by using MTT, flow cytometry and clonogenic survival assays. A dual-luciferase reporter assay was performed to test whether miR-375 binds to the 3'-untranslated region (3'-UTR) of target mRNA. The expression level of miR-375 in OSCC tissues was significantly lower than that in normal oral epithelial tissues, and low miR-375 expression was correlated with higher incidence of lymph node metastasis and poor survival of OSCC patients. Upregulation of miR-375 significantly inhibits growth, induces cell cycle arrest in G0/G1 phase, increases apoptosis and enhances radiosensitivity in OSCC cells. Analysis of luciferase activity demonstrated that miR-375 binds to the 3'-UTR of insulin like growth factor 1 receptor (IGF-1R). Small interfering RNA (shRNA)-mediated IGF-1R knockdown mimics the effects of miR-375 upregulation, while overexpression of IGF-1R partially reverses those effects in OSCC cells. It was obviously demonstrated that miRNA-375 inhibits growth and enhances radiosensitivity in OSCC cells by targeting IGF-1R, suggesting that miR-375 may be a potential therapeutic target for OSCC patients.

Zhang B ，Li Y ，Hou D ，Shi Q ，Yang S ，Li Q ... -  《-》