Chemo-resistance and microRNA-200c expression in human pancreatic cancer stem cells

Abstract

Objective To investigate the sensitivity of human pancreatic cancer stem cells to chemotherapy and the expression of microRNA(miRNA, miR)- 200c in cancer stem cells. Methods CD24+ CD44+ ESA+ cells were sorted from PANC- 1 cell line by fluorescence- activated cell sorter(FACS).The stem like properties of this subpopulation were assessed by non- obese diabetic (NOD)/severe combined immunodeficiency(SCID) xenograft transplantation experiment.Sensitivity to gemcitabine and apoptosis ratio of pancreatic cancer stem cells and PANC- 1 cells were detected by methyl thiazol tetrazolium(MTT)assay and FACS respectively.The real- time fluorescent quantitative polymerase chain reaction(FQ- PCR)was used to detect miR- 200c expression in pancreatic cancer stem cells and PANC- 1 cells Results CD24+ CD44+ ESA+ cells(0.8%) were isolated in PANC- 1 cells.NOD/SCID xenografl transplantation experiment confirmed that the sub- group had the characteristics of cancer stem cells.The half inhibition concentration(IC50)of gemcitabine was significantly higher in pancreatic cancer stem cells group[(19.15±1.53)μmol/L] than in PANC- 1 cells group[(0.86± 0.18)μmol/L](P< 0.05).After the interference of gemcitabine(1, 10μmol/L), the apoptosis ratio was significantly lower in pancreatic cancer stem cells group[(0.69±0.09)% and(0.90±0.13)%]than that in PANC- 1 cells group[(60.54±3.73)% and(91.76±5.07)%](P< 0.05).The relative miR - 200c expression level in cancer stem cell line[(0.15±0.01)] was significantly lower than that in PANC- 1 cell line[(1.00±0.09)](P< 0.05) Conclusion The expression of miR- 200c was significantly reduced in pancreatic cancer stem cells which were significantly chemo- resistant,and miR - 200c may play an important role in the chemo- resistance of pancreatic cancer stem cells. Key words: Pancreatic cancer; Stem cells; Chemoresistance; MicroRNA-200c