2001•Zhonghua zhongliu zazhiRequires access
Expression and function of protein kinase C-α and βI isoenzymes in drugresistant gastric cancer cells
Ling Li
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Abstract
Objective To study the expression and function of PKCα and βⅠ isoenzymes in drugresistant cells of gastric cancer. Methods Two tumor cell lines were used in the study: gastric cancer SGC7901 and its drugresistant counterpart SGC7901/VCR stepwiseselected by various concentrations of vincristine. The expression of PKCα and βⅠ isoenzymes in SGC7901 and SGC7901/VCR was detected by immunohistochemistry, laser confocal scanning microscopy and Western blot. The effects of antiPKCα or βⅠ antibody on adriamycin accumulation in SGC7901/VCR cells were determined by flow cytometric analysis. Results SGC7901 cells exhibited positive staining of PKCα. The staining of PKCα in SGC7901/VCR was stronger than that in SGC7901 cells. The higher the concentrations of vincristine, the stronger staining of PKCα was observed on SGC7901/VCR cells. Both SGC7901 and SGC7901/VCR cells were positive for PKCβⅠ, but without difference in staining intensity. Comparing with SGC7901, SGC7901/VCR cells showed decreased adriamycin accumulation; the decrease was more marked with the increase in concentrations of vincristine for selection of cells. Increased adriamycin accumulation in SGC7901/VCR was observed when coincubated with antiPKCα but not antiPKCβⅠantibodies. Conclusion PKCα may play a role in multidrug resistance of gastric cancer cells SGC7901/VCR.