Kindlin-2-mediated upregulation of ZEB2 facilitates migration and invasion of oral squamous cell carcinoma in a miR-200b-dependent manner.

The miR-200 family suppresses epithelial-mesenchymal transition by inhibiting ZEB1 and ZEB2 mRNA translation in several types of cancers. Kindlin-2 is a target gene of miR-200b and its expression level correlates positively to ZEB2 in oral squamous cell carcinoma (OSCC). Whether Kindlin-2 and ZEB2 share a competitive endogenous RNAs regulatory network in OSCC remains unclear. Here, we studied the expression levels of miR-200b, Kindlin-2, and ZEB2 and found direct interaction between miR-200b, ZEB2, and Kindlin-2 mRNA in OSCC. A series of experiments was performed to elucidate the role of miR-200b and Kindlin-2 in OSCC cells. To further investigate whether Kindlin-2 regulates ZEB2 as a "ceRNA", we utilized pools of siRNAs to deplete Kindlin-2 or ZEB2 in Tca-8113 cells. Significantly elevated expression levels of Kindlin-2 and ZEB2, down-regulated mRNA levels of miR-200b, and a positive correlation between Kindlin-2 and ZEB2 were found in OSCC cells. Additional results suggest that miR-200b directly targets ZEB2 and that Kindlin-2 3'UTR miR-200b repressed both the migration and invasive functionality of Tca-8113. Kindlin-2 and ZEB2 are involved in accelerated migration and invasion of Tca-113 cells in vitro and Kindlin-2 controlled ZEB2 expression. However, Kindlin-2-mediated ZEB2 regulation did not depend on miRNAs. These results indicate that Kindlin-2 does not act as ZEB2 ceRNA and modify the migration of Tca-8113 cells. Our results improve our understanding of the underlying molecular and cellular mechanisms of oral cancer metastasis.

Circulating high mobility group AT-hook 2 and pleomorphic adenoma gene 1 in blood of patients with oral squamous cell carcinoma.

BACKGROUND: High mobility group AT-hook 2 (HMGA2) and pleomorphic adenoma gene 1(PLAG1) have been demonstrated to be elevated in many malignant tumors. However, the aim of this study was to evaluate HMGA2 and PLAG1 levels in blood as a non-invasive biomarker for oral squamous cell carcinoma (OSCC) diagnosis. METHODS: qRT-PCR was performed to measure circulating HMGA2 and PLAG1 levels in OSCC patients (n=43) and matched cancer-free blood control group (n=21). Clinical data of all patients were recorded. RESULTS: Circulating HMGA2 and PLAG1 in the 43 OSCC patients was significantly higher than in control group (P<.001, P=.038, respectively). Furthermore, HMGA2 expression in OSCC patients with poor-moderate differentiation was increased compared with well-differentiated group. However, no significant differences in PLAG1 expression were detected when differentiation was considered. In addition, the receiver operating characteristic (ROC) curve analysis for circulating HMGA2 revealed an area under the ROC curve of 0.876 (95% confidence interval, 0.793-0.959; P<.001) with 65.1% sensitivity and 100% specificity in discriminating OSCC from controls at a cutoff value of 14.380, demonstrating significant diagnostic value for OSCC. CONCLUSION: Circulating HMGA2 levels are increased in OSCC patients and may potentially serve as a significant index to evaluate OSCC diagnosis.

PTENp1, a natural sponge of miR-21, mediates PTEN expression to inhibit the proliferation of oral squamous cell carcinoma.

PTENp1, non-coding RNA (ncRNA) pseudogene, is involved in oral squamous cell carcinoma (OSCC). The precise effects mediated by PTENp1 transcripts within intricate regulatory networks involving molecular interactions with ancestral gene PTEN and tumorigenicity in OSCC remain unclear. Here, we found that PTENp1 was aberrantly expressed in OSCC. There was a positive correlation between the expression levels of PTENp1 and PTEN. Further, we showed that PTENp1 acted as a competing endogenous RNA that protects PTEN transcripts from being inhibited by miR-21, and consequently inhibited proliferation and colony formation and triggered S-G2/M cell cycle arrest through the AKT pathway. Also, the homogeneous relationship between expression of PTENp1 and PTEN was confirmed in OSCC tumor xenografts. Finally, low expression of PTENp1 and PTEN was negatively associated with histological differentiation and OSCC prognosis. The present work provided the first evidence for the extraordinary crosstalk among PTENp1, PTEN, and miR-21, and rendered a new light on the treatment of OSCC. © 2016 Wiley Periodicals, Inc.