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Objective To construct BCR-ABL SH3-T79Y mutant recombinant adenovirus vectors and investigate its effects on apoptosis of K562/G01 cells.Methods SH3-T79Y mutant was amplified by overlapping PCR with pMig210 as template and cloned into recombinant adenovirus vectors .After identifying , packaging and amplifying , the recombinant adenovirus vectors containing SH 3-T79Y mutant was collected .Recombinant adenovirus vectors were transferred into K562/G01 cells.Then transfection efficiency was determinated , changes of cell morphology were observed by Wright 's staining , cell apoptosis was evaluated by flow cytometry , BCR-ABL and CrkL phospho-rylation was detected by Western blot .Results The vectors were successfully constructed .Transfection efficiency was more than 80%after transferring into K562/G01 cells for 72 h;there was obvious apoptosis phenomenon , cell apoptosis significantly increased to 32.46% compared with the control groups ( P<0.05 ) , BCR-ABL and CrkL phosphorylation significantly decreased and so did the expression of BCR-ABL( P<0.05 ) .Conclusions Success-fully constructed the SH 3-T79 Y mutant recombinant adenovirus vectors and it may promote the apoptosis of K 562/G01 cells by inhibiting BCR-ABL and CrkL phosphorylation .
ABSTRACT
Objective To explore the apoptosis of K562/G01 cells induced by triptolide through MDM2/p53 signaling pathway. Methods K562/G01 cell line was treated with different concentrations of triptolide. MTT was used to detect the cell proliferation inhibition rate. FCM was used to determine the apoptosis rate changes in 12 h and 24 h. The mRNA expression levels of bcr-abl, XIAP, MDM2, p53 were detected by real-time quantitative PCR. Results After treatment by 10, 20, 40, 80, 100 nmol/L TP in 12, 24, 48 h, the viability of K562/G01 cells was inhibited in time-dose dependence manner. K562/G01 cells was treated by 20 nmol/L, 40 nmol/L TP after 12 h, 24 h, the cell apoptosis rate was rising with drug concentration and time. The bcr-abl, XIAP, MDM2 mRNA expression was down-regulated and p53 mRNA expression was up-regulated by TP. Conclusion TP can inhibit the growth of K562/G01 cell line and induce apoptosis through XIAP-MDM2-p53 signaling pathway.
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Objective To analyze the influence of SH3 domain mutant (ABL SH3-T79Y) in BCR-ABL protein of chronic myeloid leukemia (CML) in combination with imatinib (IM) on the proliferation of CML cells in vivo and vitro, and to discuss the mechanism thereof. Methods Recombinant ABL SH3-T79Y mutant adenovirus vectors which were successfully constructed in previous work was used with IM to treat K562/G01 cells, then the cell-colony forming ability of K562/G01 cells was determined by clone formation assay, and cell cycle was assessed by flow cytometry. KCL22 cells were treated by recombinant SH3-T79Y and IM to construct subcutaneous solid tumor model in Balb/c nude mice, then the formation rate of subcutaneous tumor was estimated, the pathological examination was conducted, and the proliferation ability of KCL22 cells was assayed. K562/G01 cells were treated by SH3-T79Y and IM in combination, and the expression levels of p-BCR-ABL, BCR-ABL, p-CrkL, CrkL and Cyclin-D1 protein were determined by Western blotting. Cells treated with PBS, null recombinant adenovirus vectors or IM alone served as control groups. Results Compared to the 3 control groups, clone forming rate of K562/G01 cells decreased significantly (P<0.05) and cell cycles were arrested at S phase after being combined SH3-T79Y and IM treatment. The subcutaneous solid tumor formation rate in KCL22- Balb/c nude mice was 16.7% after combined SH3-T79Y and IM treatment, and large number of tumor cells were observed in tumor pathology examination. Western blotting revealed that the expression levels of p-BCR-ABL, p-CrkL, BCR-ABL, CrkL and Cyclin-D1 were decreased in K562/G01 cells. Conclusion Combined treatment of SH3-T79Y and imatinib may inhibit the proliferation of CML cells in vivo and in vitro by decreasing BCR-ABL and CrkL phosphorylation as well as Cyclin-D1 protein.
ABSTRACT
Objective To investigate the possible mechanism of mitochondrial in chronic myeloid leukemia cells K562/G01 cells apoptosis induced by triptolide.Methods K562/G01 cells were treated with different concentrations of triptolide.MTT assay was used to assess cytotoxic effect.FCM was used to determine apoptosis rate,mitochondrial membrane potential and the activity of Caspase-9 of each experimental group.Real-time quantitative PCR assay was used to quantify mRNA levels of Caspase-9 and cytochrome C and Western blot assay was used to determine protein levels of cytochrome C.Results Triptolide inhibited the growth and proliferation of K562/G01 cells in a time-and dose-dependent manner (both P ＜ 0.001).Meantime,triptolide could make the mitochondria membrane potential fade away and enhance the activity of Caspase-9 (F =566.431,2 555.485,P ＜ 0.001).In addition,triptolide could dose-dependently up-regulated the transcription of Caspase-9 and cytochrome C (F =61 007.702,452 121.760,P ＜ 0.001),and the protein expression of cytochrome C,whose gray value in each experimental group was 21.54±0.59,39.63±0.58,53.29± 1.47 and 75.68±1.87 (F =5 677.928,P ＜ 0.001) respectively.Conclusion Triptolide could potently inhibit the growth and proliferation of K562/G01 cells,and the mitochondria apoptosis pathway might be one of the important apoptosis mechanisms in chronic myeloid leukemia cells induced by triptolide.