Abstract
Long non-coding RNA (lncRNA) SOX2 overlapping transcript (SOX2OT) has been shown to play an oncogenic role in diverse cancers, generating eight transcript variants. SOX2 is located in the third intron of SOX2OT. However, the biological function of SOX2OT in cervical cancer and implication with SOX2 remain to be further explored. In this study, we screened the expression pattern of different SOX2OT transcript variants in cervical cancer cells. Interestingly, both high-expression levels of SOX2OT transcript 7 (SOX2OT-7) and SOX2 were detected in C-33A (HPV-) and SiHa (HPV16+) cells. Thus, C-33A and SiHa cells were conducted to investigate the effects of SOX2OT on cell growth, migration and invasion. Finally, rescue experiments were performed to confirm the role of SOX2 in SOX2OT-mediated regulation of cervical cancer progression. The results showed that knockdown of SOX2OT suppressed cell viability, arrested cell cycle and ameliorated migration and invasion ability of C-33A and SiHa cells. Ectopic expression of SOX2OT-7 exacerbated cervical cancer cell proliferation, migration and invasion. In addition, we found that the expression levels and protein stability of SOX2 were positively regulated by SOX2OT. Inhibition of SOX2 could block the malignant phenotypes of C-33A and SiHa cells by SOX2OT-7. In conclusion, these findings indicate that lncRNA SOX2OT contributes to the growth, migration and invasion of cervical cancer cells by modulating SOX2. Importantly, we demonstrate that the transcript SOX2OT-7 may be a novel and promising biomarker for both HPV- and HPV16+ cervical cancer.