Effects of ABL SH3-T79Y mutant combined with imatinib on the proliferation of chronic myeloid leukemia cells / 解放军医学杂志

ABSTRACT

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.