Identification Of Laryngeal Carcinoma Related Gene 1 As A Target Gene Of Microrna-21-5p In Laryngeal Carcinoma

The laryngeal carcinoma related gene 1 (LCRG1) has been implicated as a tumor suppressor in laryngeal cancer. However, the microRNAs (small non-coding RNAs of approximately 22 nucleotides in length) that regulate LCRG1 expression remain elusive. In this study, quantitative PCR analysis first showed that the average level of miR-21-5p was elevated in primary laryngeal carcinoma tissues compared to paired adjacent non-tumor tissues. Thus, we explored the potential regulation of miR-21-5p on LCRG1. PITA algorithm predicted that two sites within LCRG1 mRNA 3'UTR, which reside at +743 position and +938 position, respectively, might be targeted by miR-21-5p. Dual luciferase reporter assay confirmed that miR-21-5p mimic specifically decreased luciferase activity of the reporter harboring 3'UTR+743 target site. With respect to the 3'UTR+938 site, the influence of miR-21-5p on luciferase activity was not sequence specific. Further, we observed that miR-21-5p mimic transfection decreased the LCRG1 protein in human laryngeal carcinoma Hep2 cells as indicated by Western blotting analysis, and promoted cell growth, migration and invasion as evidenced by MTT assay and transwell migration assay and matrigel invasion assay. Of note, the effects of miR-21-5p inhibitor treatment are opposite to those of the miR-21-5p mimic. Taken together, this study identifies that the tumor suppressor LCRG1 is targeted by the oncogenic miR-21-5p. This finding may help us to better understand the dysregulation of cancer-associated genes associated with microRNAs and eventually improve the diagnosis and target therapy for laryngeal carcinoma.