Objective: To investigate the effect of valproic acid (VPA) on MICA gene expression in human lung carcinoma cell lines: A549, SP-CA-1, NCIH446.
Methods: Different concentration of VPA were applied to treat A549, SP-CA-1, NCIH446 cells respectively and the untreated cells as the control. The effect of the VPA on the cells were observed. Reverse Transcriptase PCR and Immune-Fluorescence staining were used to detect the changes of mRNA, protein level of MICA gene in the three cell lines treated with 1.50 mmol/L and 3.00 mmol/L VPA for 4 days under the concentration of VPA from 0.75 to 12.0 mmol/L. The viability of lung cancer cells after NK effect in the VPA(+) and VPA(-) treatment were evaluated with LDH method.
Results: The inhibition effects were observed when the VPA concentration was 6.0 mmol/L above compared to control group, VPA induced the increasing expression of MICA and in turn enhanced the NK killing effect on the cells in a concentration-depended pattern.
Conclusion: VPA induced MICA expression, NK killing effect in the VPA(+) treatment lung cancer cells was significantly stronger than that of VPA(-) condition, which implied a new mechanism of anticancer method and could be a new approach to cancer therapy.