To evaluate the cytotoxic effect of TOPK inhibitor in combination with cisplatin in non-small cell lung cancer

• Main Authors: Pyea-Yoo Kim, 金佩瑜
• Other Authors: Jin-Mei Lai
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/53462596390468237179

碩士 === 輔仁大學 === 生命科學系碩士班 === 103 === Surgical resection and cisplatin-based chemotherapy are the mainstays of treatment for EGFR wild type lung cancer patients. However, cisplatin has many side effects and has been reported to select the generation of CSCs (cancer stem cells), thereby causing drug resistance and treatment failure. Therefore, identification of a drug combination regiment to reduce the dosage of cisplatin may be helpful for lung cancer treatment. TOPK is a Ser/Thr kinase that is overexpressed in lung and metastatic cancer, while not in most normal tissue. Knockdown the expression of TOPK can decrease the colony formation of lung cancer cells. Hence, by utilizing a TOPK inhibitor, HI-TOPK-032, this thesis aims to evaluate its potential role in lung cancer treatment. First, the results indicate HI-TOPK-032 can inhibit the growth of A549 lung cancer cells with IC50 4.41 ± 0.86 μM (24 hr), 2.69 ± 0.83 μM (48 hr) and 2.40 ± 0.20 μM (72 hr). Similar growth inhibition effects were also found in CL97, CL141, CL152, H23, PC9 and HCC827 cells. We further showed that HI-TOPK-032 combined with cisplatin has synergistic effect to conduct cell death (24 hr CI=0.472-0.843 and 48 hr CI=0.585-0.896). Subsequently, using HI-TOPK-032 combined with cisplatin in constant ratio 1:2, I also verified this synergistic effect. Mechanistically, HI-TOPK-032 can reduce the phosphorylation of TOPK, Histone H3 and AKT, and increase cisplatin-induced H2AX, PUMA and cleaved-caspase 3, but decrease p21, indicating it may assist in the cytotoxic effect of cisplatin through affecting cell cycle regulation and cisplatin-independent apoptosis. HI-TOPK-032 can also kill lung cancer sphere cells, such as CL97, CL141 and CL152, with the IC50 ranging from 1.09-1.13 μM (24 hr) and 0.46-1.01 μM (48 hr), indicating HI-TOPK-032 may have the ability to kill lung CSCs. In conclusion, the above results show TOPK is a valuable target for lung cancer treatment and these will assist in the target therapy focusing primarily on TOPK or in combination with cisplatin as a new strategy for lung cancer treatment.