Compound Zhe Bei Particles Mediated Intervention Of Micrornas - 17-92 To Study Drug Resistance In Acute Lymphoblastic Leukemia

Objective1. To investigate the expression level of miR-17-92in peripheral blood lymphocytes of Refractory Acute Lymphocytic Leukemia.2. To investigate the possible role of miR-17-92in the development of multidrug resistance (MDR) in Acute Lymphocytic Leukemia cell line L1210/DDP.3. To observe reversal effect of compound zhebei granule (CZBG) in Acute Lymphocytic Leukemia cell line L1210/DDP, and explore its possible mechanism.Method1. Peripheral blood lymphocytes of21RALL patients and15chemotherapy-sensitive ALL patients in vivo were isolated respectively. MTT assay was carried out to evaluate the sensitivity of lymphocytes to adriamycin (ADM) and cisplatin (CDDP) in patients. Total RNA was extracted from lymphocytes of blood sample from32patients. The real-time PCR method was performed to detect the expression levels of miR-17-92.2. Establishing L1210cell line resistant to DDP (L1210/DDP). Using real-time PCR analysis to detect the expression difference of miR-17-92between multidrug-resistant acute lymphocytic leukemia cell line L1210/DDP and its parental L1210cell line. L1210/DDP cells were transfected with the inhibition of miR-17-92(miR-17-92sponge) or negative control (sponge vector) by Lipofectamine2000to down-regulate the expression level of miR-17-92in L1210/DDP cells. MTS was used to analyze drug sensitivity to DDP and ADR after transfection.3. The inhibition rates of adriamycin on multidrug-resistant acute lymphocytic leukemia cell line L1210/DDP and its parental L1210cell line were determined by MTS assay, evaluation of multidrug resistance and the reversal effect of Adriamycin was calculated according to half inhibitory concentration (IC50) of adriamycin on multidrug-resistant acute lymphocytic leukemia cell line L1210/DDP and its parental L1210cell line. Real-time PCR detection was executed to investigate miR-17-92and PTEN expression in the resistant cells after treatment of compound zhebei granule (CZBG)Result1. The MTT assay result showed that the inhibition rates (IR) in18RALL patients were less than30%, which were sensitive or drug resistant, and the inhibition rates (IR) in14chemotherapy-sensitive ALL patients larger than30%, which were chemotherapy-sensitive. The relative expression levels of miR-17-92in lymphocytes of RALL patient and chemotherapy-sensitive ALL patients were7.12±1.03and3.21±0.63respectively. The results showed that compared with the chemotherapy-sensitive ALL patients, the relative expression of miR-17-92in lymphocytes of RALL patients was significantly increased, p<0.05.2. miR-17-92was high expressed in multidrug-resistant acute lymphocytic leukemia cell line L1210/DDP. In vitro drug sensitivity assay showed that the down-regulation of miR-17-92sensitized L1210/DDP cells to anticancer drugs of DDP and ADR. Conclusion: miR-17-92was high expressed in L1210/DDP cell line. Inhibition of miR-17-92can sensitize L1210/DDP cell to DDP and ADR. reverse drug resistance in part.3. The resistance index of drug resistant cell line was, the reverse rate of CZBG was7.25. CZBG could significantly decrease the expression of miR-17-92.Conclution1. The expression level of miR-17-92in lymphocytes of RALL patients was up-regulated. miR-17-92may have relationship with the occurrence and development of multi-drug resistance in Refractory Acute Lymphocytic Leukemia.2. miR-17-92was high expressed in L1210/DDP cell line. Inhibition of miR-17-92can sensitize L1210/DDP cell to DDP and ADR. reverse drug resistance in part.3. CZBG combined ADR illustrated a significiant reversal effect on the multidrug-resistant acute lymphocytic leukemia cell line L1210/DDP, the mechanism may be to reduce miR-17-92gene expression and increase PTEN gene.