[Study on the expression of DNA excision repair biomarkers in cispatin-treated lung cancer cell line].

OBJECTIVE

To study the expression levels of ERCC2, UDG, and PCNA in cisplatin-treated A549 cell line.

METHOD: Comet assay, RT-PCR, and western blot were used to study the mRNA and protein expression levels of ERCC2, UDG, and PCNA.

RESULTS

When treated with IC(20) cisplatin, the DNA damage level increased as the cisplatin treated time increased within 24 h of cisplatin treatment. The tail state 12 h and 24 h after treatment was 5.02 +/- 0.68 and 7.22 +/- 0.53 respectively, which was significantly higher than those of the controls (2.73 +/- 0.29). The tail state 24 h after treatment was not significantly different from that of the controls. The DNA damage level decreased to normal after cisplatin treatment in 24 h (tail state 3.64 +/- 0.7). The expression levels of ERCC2, UDG, PCNA protein (4.37 +/- 0.57, 5.47 +/- 0.46, 2.21 +/- 0.47 respectively) and mRNA (0.71 +/- 0.08, 0.74 +/- 0.06, 0.82 +/- 0.09) were increased significantly within 24 h exposure and decreased to normal 24 h after cisplatin treatment. The 3 enzymes' mRNA and protein expression increased when treated with cisplatin, but the changes of protein level were slower than those of mRNA levels.

CONCLUSIONS

The DNA repair capability in A549 cells increases after cisplatin treatment. Cisplatin was a positive regulation of ERCC2, UDG, PCNA expression levels, which causes the increase of mRNA, and protein. The positive regulation only works in a short time and returns normal after 24 h of cisplatin treatment.