The miR-1204 regulates apoptosis in NSCLC cells by targeting DEK

Introduction. This study endeavors to analyze the effects of miR-1204 on the expression of DEK oncogene in non-small cell lung cancer (NSCLC) cell lines and to study the molecular mechanisms of these effects. Material and methods. The miR-1204 mimics and inhibitors were transfected into the (A549 and SPC) NSCLC cells. Then the mRNA levels, cell viability, apoptosis rate, morphology and caspase activity were determined. The expression of apoptosis-related proteins Bcl-2 and Bax was also analyzed. Results. In NSCLC cell lines (A549 and SPC), DEK mRNA levels were down-regulated in miR-1204 overex­pression group. In miR-1204 inhibition group, the expression of DEK mRNA showed an opposite trend. The overexpression of miR-1204 increases the apoptosis rate in NSCLC cells. The Bcl-2 levels in the miR-1204 over­expression group were decreased, while the Bax level was increased. In the miR-1204 inhibition group, expression of Bcl-2 and Bax showed opposite trends. Cell staining revealed cell’s morphological changes; the apoptosis in the miR-1204 overexpression group revealed significant morphological features, such as brighter nuclei and nu­clear condensation. Results indicated a typical characteristic of apoptosis in the miR-1204 overexpression group. Caspase-9 and Caspase-3 were involved in the apoptosis pathway, which was mediated by miR-1204 and DEK. Conclusions. The miR-1204 induces apoptosis of NSCLC cells by inhibiting the expression of DEK. The mech­anism of apoptosis involves down-regulation of Bcl-2 and up-regulation of Bax expression. Moreover, the apoptosis was mediated by mitochondria-related caspase 9/3 pathway.