Role of Bclª²2ª²related antiª²apoptosis mechanism in drug resistance of leukemia

    ZHAO Xinª²Han£¬LI Jing£¬LI Linª²Lin£¬MA Xin£¬TIAN Hongª²Gang£¬LIU Shanª²Xi

    Key Laboratory of Environment and Genes Related to Diseases of Ministry of Education, Department of Medical Oncology, First Hospital, Xi¬ðan Jiaotong University, Xi¬ðan 710061, China

    ¡¾Abstract¡¿ AIM: To study the role of antiª²apoptosis mechanism of Bclª²2 in multidrug resistance of leukemia. METHODS: Human chronic granulocytic leukemia cell strain K562 and adriamycin(ADR)ª²resistant cell strain K562/AO2 were used as research subjects and the changes of the two cell strains by the action of ADR as well as the Bclª²2 protein expression level were observed. MTT assay was used to measure the cell survival(A value) of K562 and K562/AO2 cell strains after the action of ADR. DNA agarose gel electrophoresis was used to observe cells¬ð apoptosis and flow cytometer to detect the apoptotic rates, cell cycle and the rates of Bclª²2 protein expression. RESULTS: MTT method showed that the number of survival cell reduced in K562 cell strain affected by ADR and the A value of K562 cell strain affected by 1.00 ¦Ìmol/L ADR for 48 h was (0.803¡À0.032). The DNA agarose gel electrophoresis and flow cytometry(FCM) showed that apoptosis occurred in the K562 cell strain affected by ADR. FCM found that the Bclª²2 positive expression rate of K562 cell strains affected by ADR was low and its value affected by 1.00 ¦Ìmol/L ADR for 48 h was(38.67¡À0.45)%. CONCLUSION: The main mechanism of drug resistance is implemented by way of inhibiting cell apoptosis. bclª²2 is the major controlling gene for apoptosis and it is deemed as a drugª²resistant gene. ......