Effects of 5-fluorouracil on biological characteristics and drug resistance mechanisms of liver cancer cell line PLC/RAF/5

• Main Authors: CHENG Kangwen, LI Qi, ZHAN Yongqiang
• Format: Article
• Language: zho
• Published: Editorial Department of Journal of Clinical Hepatology 2015-09-01
• Series: Linchuang Gandanbing Zazhi
• Online Access: http://www.lcgdbzz.org/qk_content.asp?id=6823
• ISSN: 1001-5256; 1001-5256

ObjectiveTo study the changes in biological characteristics of a liver cancer cell line PLC/RAF/5 after repeated exposure to a chemotherapy drug, 5-fluorouraci (5-FU), and to investigate the relationship between drug-resistant liver cancer cells and liver cancer stem cells. MethodsA low concentration of 5-FU (1 μg/ml) was used to treat the human liver cancer cell line PLC/RAF/5 repeatedly to establish the PLC/RAF/5/5-FU cell line. Morphological differences between the two types of cells were observed. The inhibitory effects of different concentrations of 5-FU (0, 0.25, 0.5, 1, 1.5, and 2 μg/ml) on the proliferation of the two types of cells were determined using the CCK-8 assay. Apoptosis of the two types of cells after exposure to different concentrations of 5-FU (0.5, 1, and 2 μg/ml) for 48 h was analyzed using flow cytometry. The proportions of side population cells in both types of cells were measured using flow cytometry. The colony-forming ability was compared between the two types of cells by the plate colony-forming assay. The expression of Bax, Bcl-2, ABCG2, and FoxM1 proteins in both types of cells was examined by Western blot. Between-group comparison was performed by t test. ResultsThe PLC/RAF/5/5-FU cell line was successfully established using the chemotherapy drug 5-FU. Compared with the PLC/RAF/5 cells, the PLC/RAF/5/5-FU cells had a larger volume, fewer protrusions, a changed shape of a long shuttle, and enhanced refractivity. Moreover, compared with the parent cells, the PLC/RAF/5/5-FU cells had a significantly lower sensitivity to the inhibitory effect of 5-FU on proliferation, a significantly lower proportion of cells at the G0/G1 phase of the cell cycle, significantly higher proportions of cells at the S and G2/M phases, significantly higher resistance to apoptosis, a significantly higher proportion of side population cells, and significantly enhanced proliferation (P＜0.05). According to the results of Western blot assay, the expression of Bcl-2, FoxM1, and ABCG2 proteins in the PLC/RAF/5/5-FU cells was significantly increased (P＜0.01), while the expression of Bax protein in the PLC/RAF/5 cells was significantly increased (P＜0.01). ConclusionLiver cancer stem cells are probably responsible for drug resistance of the PLC/RAF/5-FU cell line. Exposure to a low concentration of 5-FU (1 μg/ml) can enrich liver cancer stem cell-like cells.