[Study on the Effect and Mechanism of Tetrandrine on Bone Marrow Mesenchymal Stem Cell-Mediated Drug Resistance in Leukemia].

OBJECTIVE:To explore the role of bone marrow mesenchymal stem cells (BMSC)，an essential element of the bone marrow microenvironment, in multidrug resistance(MDR) of K562 cells, as well as the reversal effect of tetrandrine (TET) on BMSC-mediated MDR and its potential mechanism. METHODS:A mixed co-culture system and a transwell co-culture system for BMSC and K562 cells were established, and the cells were divided into different groups and treated with daunorubicin (DNR) alone or combined with TET and DNR. The CCK-8 assay was used to detect the proliferation of K562 cells in each group, and the cell inhibition rate was calculated. Cytometric bead array (CBA) was used to detect the expression levels of IFN, IL-2, IL-6 and IL-10 in the supernatant of different groups. RT-qPCR and Western blot were used to detected the expression of STAT3 at mRNA and protein levels, respectively. RESULTS:Compared with K562+DNR group, the inhibition rate of DNR on K562 cell proliferation in K562+BMSC+DNR group was significantly decreased (P < 0.05), while the levels of IL-6 in the culture supernatant and phosphorylated STAT3 in K562 cells were significantly increased (P < 0.05). Compared with K562+BMSC+DNR group, the inhibition rate of DNR on K562 cell proliferation in K562+BMSC+DNR+TET group was significantly increased (P < 0.05), while the level of IL-6 and phosphorylated STAT3 was significantly decreased (P < 0.05). CONCLUSION:BMSC can promote the drug resistance of leukemia cells, and TET may reverse the BMSC-mediated drug resistance via inhibiting IL-6/STAT3 signaling pathway.