ABSTRACT
Chemoradiation therapy is an important component of the curative treatment for oesophageal carcinomas. These therapeutic effects are prevented in patients according to radioresistance and multi-drug resistance, and the cause of such resistance remains unclear. In this study, we identified the role of miR-193a-3p in modulating the radioresistance and chemoresistance of oesophageal cancer cells. We found that KYSE150 and KYSE410 cells could be characterized as relatively radiation-sensitive and radiation-resistant cells, respectively. Similarly, KYSE150 and KYSE410 cells were found to be chemosensitive and chemoresistant, respectively. Over-expression of miR-193a-3p increased the radioresistance and chemoresistance of oesophageal squamous cell carcinoma (ESCC) cells. In contrast, the down-regulation of miR-193a-3p decreased the radioresistance and chemoresistance of ESCC cells. In addition, miR-193a-3p inducing DNA damage has also been demonstrated through measuring the level of gamma-H2AX associated with miR-193a-3p. Moreover, a small interfering RNA(siRNA)-induced repression of the PSEN1 gene had an effect similar to that of miR-193a-3p up-regulation. The above processes also inhibited oesophageal cancer cells apoptosis. These findings suggest that miR-193a-3p contributes to the radiation and chemotherapy resistance of oesophageal carcinoma by down-regulating PSEN1. Thus, miR-193a-3p and PSEN1 might be potential biomarkers for chemoradiation resistant cancers.