AIM: To investigate the expression and function of classicalprotein kinase C (PKC) isoenzymes in inducing MDRphenotype in gastric cancer cells.METHODS: Two cell lines were used in the study: gastriccancer cell SGC7901...AIM: To investigate the expression and function of classicalprotein kinase C (PKC) isoenzymes in inducing MDRphenotype in gastric cancer cells.METHODS: Two cell lines were used in the study: gastriccancer cell SGC7901 and its drug-resistant cell SGC7901/VCRstepwise-selected by vincristine 0.3, 0. 7 and 1.0 mg@ L-1 ,respectively. The expression of classical PKC (cPKC)isoenzymes in SGC7901 cells and SGC7901/VCR cells weredetected using immunofluorescent cytochemistry, laserconfocal scanning microscope and Wsstern blot. The effectsof anti-PKC isoenzymes antibody of adriamycinaccumulation in SGC7901/VCR cells were determined usingflow cytometric analysis.RESULTS: (1) SGC7901 cells exhibited positive staining ofPKC-α. SGC7901/VCR cells exhibited stronger staining ofPKC-α than SGC7901 cells. The higher dosage vincristineselected, the much stronger staining of PKC-α was observedon SGC7901/VCR cells. (2) Both SGC7901 and SGC7901/VCRcells exhibited positive staining of PKC-βⅠ and PKC-βⅡ withno significant difference. ( 3 ) Compared with SGC7901,SGC7901/VCR cells had decreased adriamycin accumulationand retention. Accumulation of adriamycin in SGC7901 was5.21 + 2.56 mg@ L-1, in SGC7901/VCR 0.3 was 0.85 + 0.29 mg@L-1 , in SGC7901/VCR 0.7 was 0.81 + 0.32 og@ L-1 , and inSGC7901NCR 1.0 was 0.80 + 0.33 mg @ L-1; Retention ofadriamycin in SGC 7901 was 2.51 + 1.23 mg@L-1, in SGC7901/VCR 0.3 was 0.47 + 0.14 mg@ L-1 , in SGC7901/VCR 0.7 was 0.44 + 0.15 mg@ L-1, and in SGC 7901/VCR 1.0 was 0.41 + 0.1 1mg @ L-1 . (4) Fluorescence intensity presented adriamycinaccumulation in SGC7901/VCR cells was increased from 1.14+0.36 to 2.71 +0.94 when cells were co-incubated with anti-PKC-αbut not with anti-PKC-βⅠ, PKC-βⅡ and PKCγ antibodies.CONCLUSION: PKC-α, but not PKC-βⅠ, PKC-βⅡ or PKCγ,may play a role in multidrug resistance of gastric cancercells SGC7901/VCR.展开更多
基金the National Nature Science Fundation of China,No.30030140 and No.30000066.
文摘AIM: To investigate the expression and function of classicalprotein kinase C (PKC) isoenzymes in inducing MDRphenotype in gastric cancer cells.METHODS: Two cell lines were used in the study: gastriccancer cell SGC7901 and its drug-resistant cell SGC7901/VCRstepwise-selected by vincristine 0.3, 0. 7 and 1.0 mg@ L-1 ,respectively. The expression of classical PKC (cPKC)isoenzymes in SGC7901 cells and SGC7901/VCR cells weredetected using immunofluorescent cytochemistry, laserconfocal scanning microscope and Wsstern blot. The effectsof anti-PKC isoenzymes antibody of adriamycinaccumulation in SGC7901/VCR cells were determined usingflow cytometric analysis.RESULTS: (1) SGC7901 cells exhibited positive staining ofPKC-α. SGC7901/VCR cells exhibited stronger staining ofPKC-α than SGC7901 cells. The higher dosage vincristineselected, the much stronger staining of PKC-α was observedon SGC7901/VCR cells. (2) Both SGC7901 and SGC7901/VCRcells exhibited positive staining of PKC-βⅠ and PKC-βⅡ withno significant difference. ( 3 ) Compared with SGC7901,SGC7901/VCR cells had decreased adriamycin accumulationand retention. Accumulation of adriamycin in SGC7901 was5.21 + 2.56 mg@ L-1, in SGC7901/VCR 0.3 was 0.85 + 0.29 mg@L-1 , in SGC7901/VCR 0.7 was 0.81 + 0.32 og@ L-1 , and inSGC7901NCR 1.0 was 0.80 + 0.33 mg @ L-1; Retention ofadriamycin in SGC 7901 was 2.51 + 1.23 mg@L-1, in SGC7901/VCR 0.3 was 0.47 + 0.14 mg@ L-1 , in SGC7901/VCR 0.7 was 0.44 + 0.15 mg@ L-1, and in SGC 7901/VCR 1.0 was 0.41 + 0.1 1mg @ L-1 . (4) Fluorescence intensity presented adriamycinaccumulation in SGC7901/VCR cells was increased from 1.14+0.36 to 2.71 +0.94 when cells were co-incubated with anti-PKC-αbut not with anti-PKC-βⅠ, PKC-βⅡ and PKCγ antibodies.CONCLUSION: PKC-α, but not PKC-βⅠ, PKC-βⅡ or PKCγ,may play a role in multidrug resistance of gastric cancercells SGC7901/VCR.
