Effect of Noscapine on Drug Resistance of 5-Fluorouracil-resistant Human Colon Cancer Cell Lines HT-29/5-Fu, LoVo/5-Fu and SW480/5-Fu

Objective To investigate the effect of Noscapine(Nos) on drug resistance of 5-Fu-resistant human colon cancer cell lines and its mechanism.

Methods Drug-resistant cell lines HT-29/5-Fu, LoVo/5-Fu and SW480/5-Fu were established. MTT assay was used to test IC₅₀ and cell morphology was observed. Cell cycle and apoptosis were determined by flow cytometry. RT-qPCR and Western blot were used to detect the expression and phosphorylation of P38 and the expression of drug resistance-related proteins.

Results The drug-resistant cell lines HT-29/5-Fu, LoVo/5-Fu and SW480/5-Fu were successfully constructed. Compared with control group, cell cycle of colon cancer drug-resistant cell lines HT-29/5-Fu, LoVo/5-Fu and SW480/5-Fu after Nos intervention was significantly blocked at G₀/G₁ phase (P < 0.01), the apoptosis rate was increased, the expression of P38 and phosphorylation were significantly inhibited (P < 0.01), and the expression of MRP, LRP and P-glycoprotein were significantly decreased (P < 0.01).

Conclusion Noscapine has a certain toxic effect on 5-Fu-resistant human colon cancer cells and reduces drug resistance. The mechanism may be related to the inhibition of P38 expression and phosphorylation.