Role of mitochondria pathway in signal transduction of chronic myeloid leukemia / 中国实验血液学杂志

This study was aimed to investigate the role of mitochondria pathway in signal transduction of chronic myeloid leukemia (CML). After bcr3/abl2 antisense oligodeoxynucleotide (ASO) was introduced into CML cell line K562 cells by liposomal transfection, the cell viability was detected by MTT assay, the cell apoptosis was determined by flow cytometry (FCM), the mitochondrial membrane potential (DeltaPsi) was labeled by Rhodamine 123 and examined by FCM, and the expression of mitochondrial apoptosis signal transduction pathway related proteins cytochrome C was analyzed by Western blot. The results showed that after K562 cells were exposed to 2 micromol/L of bcr3/abl2 ASO for 24 hours, bcr3/abl2 ASO significantly inhibited cell viability with inhibitory rate of 65.7%, induced the apoptosis of K562 cell line with apoptotic rate of 16.9%, and decreased mitochondrial Deltapsi of K562 cells with the reducing rate of 38.33%, enhanced the expression of cytochrome C with increase of optical density value from 2.33 +/- 0.3 to 4.78 +/- 0.1 by laser photometric scanning. It is concluded that mitochondria pathway plays an important role in signal transduction of chronic myeloid leukemia by directing apoptotic signal transduction.

Experimental research on tyrosine-kinase inhibitor STI571 and P21WAF gene clone to treat chronic myeloid leukemia / 中国实验血液学杂志

To explore the effect of a tyrosine-kinase inhibitor STI571 and P21(WAF) gene clone on the proliferation, cycle, apoptosis of leukemia cell line K562, P21(WAF) gene was obtained by RT-PCR, and its sequence was approved to be correct, then P21-pcDNA3.1 vector was constructed and transfected into K562 cell line. After selected with G418, P21-pcDNA3.1-K562 cell clone that stably expression P21(WAF) was isolated. P21(WAF) protein was identified by Western blot. The survival rate were tested by MTT. Cell cycle and apoptosis were tested by flow cytometry. The results showed that the expression of P21(WAF) protein could be detected by Western blot in P21-pcDNa3.1-K562 cells. A strong inhibition of cell proliferation was observed in P21-pcDNA3.1-K562 cells as compared with that of the control. The cells cycle were arrested in G(0)/G(1) phase. The percentage of apoptosis was declined slightly after P21-pcDNA3.1-K562 cells were combined with STI571, meanwhile its survival rate declined more slowly than that of K562 cell with STI571. In conclusion, P21(WAF) inhibits the proliferation of K562 cell, meanwhile slightly inhibits its apoptosis induced by STI571and decrease its sensitivity to STI571.