Paired related homeobox1 (PRRX1) was a newly identified Epithelial mesenchymal transition (EMT) inducer. It was found that the decreased expression of PRRX1 in breast cancer and liver cancer could enable tumor cells to obtain tumor stem cell characteristics in vitro studies. However, the role of PRRX1 in lung cancer was still unknown. The down-regulated PRRX1 gene in A549 cells was established by slow virus infection in this study. The apoptosis of A549 cells was observed after the treatment of different concentrations of cisplatin and the role of PRRX1 in the apoptosis of A549 cells was explored. MTT results showed that down-regulated PRRX1 gene could resist the inhibitory effect of cisplatin on cell proliferation. The results of flow cytometry assay showed that down-regulated PRRX1 gene could reduce the apoptosis and promote A549 cells to enter G2 phase. Mitochondrial membrane potential detection showed that PRRX1 gene could inhibit the decrease of mitochondrial membrane potential. Western blotting results showed that down-regulated PRRX1 gene could reduce the expression levels of Caspase3, caspase9, Apaf-1 and cytochrome C. In a word, down-regulation of PRRX1 could cause lung cancer cells to produce anti apoptotic ability and resistance to cisplatin, which maybe through caspase3 pathway.
Keywords: A549 cells; PRRX1; apoptosis; cisplatin.