THE EFFECT OF INHIBITION OF PLK1 EXPRESSION ON THE SENSITIVITY AND METASTASIS OF CISPLATIN IN LUNG CANCER CELL LINE A549

Rongying Zhang¹, Zelan Xu², Fangyu Ning³, Yiming Kong¹, Xiaobo Li¹, Xiaomi Wang¹, Xiaoli Yu^{4, *}

¹Department of Pulmonary and Critical Care Medicine, Taizhou First People’s Hospital, Taizhou, PR China - ²Department of Respiratory Medicine, First People's Hospital, Fuyang District, Hangzhou, PR China - ³Department of Critical Care Medicine, Affiliated Hospital of Binzhou Medical University, Binzhou, PR China - ⁴Department of Respiratory Medicine, Weifang NO.2 People's Hospital, Weifang, PR China

Objective: To investigate the effect of inhibition of polo-like kinase gene 1 (PLK1) expression on chemotherapy sensitivity and metastasis as well as invasion of lung cancer cell line A549. 

Methods: Human lung cancer cell line A549 was used for cell transfer. The control group and siRNA-PLK1 transfer group (siRNA-PLK1 group) were set up, and 4 compound holes were established in each group. The expression of PLK1 in lung cancer tissues and normal paracancerous tissues was observed by immunohistochemistry, and the expression of PLK1 in the control group and siRNA-PLK1 group was compared by the RT-PCR method. The CCK-8 assay was used to detect the effect of inhibition of PLK1 expression on chemotherapy sensitivity of lung cancer cell line A549. Apoptosis was detected by flow cytometry. CCK-8 assay was employed to detect the change in cell proliferation ability. Teanswell assay was used to observe the changes of invasion and metastasis of A549 cells. 

Results: The expression level of PLK1 in lung cancer tissues was significantly higher than that in normal adjacent tissues (P<0.05). Compared with the control group, the expression level of PLK1 in the siRNA-PLK1 group was significantly decreased (P<0.01). With the rise in cisplatin concentration, the proliferation inhibition rate of A549 cells was significantly increased, and the proliferation inhibition rate of A549 cells in the siRNA-PLK1 group was significantly higher than that in the control group (P<0.05). Apoptosis of A549 cells in the siRNA-PLK1 group was significantly higher than that in the control group (P<0.01). With the development of time, the proliferation ability of cells in both groups was on the rise, and from 24h, the proliferation ability of A549 cells in siRNA-PLK1 group was significantly lower than that in the control group (P<0.05). Compared with the control group, the ability of the siRNA-PLK1 group to clone, transfer and invade cells was significantly reduced (P<0.01).

Conclusion: Inhibition of LPK1 expression in lung cancer tissues can significantly increase the sensitivity of lung cancer cells A549 to cisplatin chemotherapy, reduce the proliferation, migration and invasion ability of lung cancer cells, and promote apoptosis.