Reversed effect of all-trans retinoic acid on enrichment of liver cancer stem cells by chemotherapy drugs / 中国药学杂志

ABSTRACT

OBJECTIVE: To investigate the relationship between chemotherapy resistance and cancer stem cells, probe the way to reverse drug resistance, and guide the rational medical treatment. METHODS: Hepatocellular carcinoma cell lines, parent and chemoresistant HepG-2, were cultured with fluorouracil (5-FU). CCK-8 cell proliferation assay was used to determine the inhibition of 5- Fu and all-trans retinoic acid (ATRA), a cell differentiation inducer. The content difference of cancer stem cells between parent and chemoresistant HepG-2 cell lines was examined by flow cytometry. Western blot and realtime PCR were preformed to probe the difference of related gene expression level between parent and chemoresistant HepG-2 cell lines. RESULTS: Our data supported that the inhibitory effect of 5-Fu alone on chemoresistant HepG-2 cells proliferation was lower than on parent HepG-2 cells. After the addition of ATRA, chemoresistant HepG-2 cells proliferation was reduced obviously. Flow cytometry results revealed that compared with parent HepG-2 cells, the ratio of CD44 and CD326 positive cells in chemoresistant HepG-2 cells was much more than that in parent HepG-2 cells. Furthermore, realtime PCR and Western blot suggested that ABCG2, BMI and OCT4 expressions were increased in chemoresistant HepG-2 cells than those in parent HepG-2 cells, while ATRA could attenuate these differences on protein expressions. CONCLUSION: Cancer stem cells enrichment relates to chemotherapy resistance, which can be reversed by ATRA through down-regulation cancer stem cells associated gene expression. This can provide new ideas for clinical rational use of anti-tumor drugs.