RESUMO
Using the BALB/c mouse multidrug resistance model of leukemia, the effect of peptide extract from scorpion venom (PESV) to the upstream signal factors of P-gp of MDR leukemia stem cells on the mouse tumor block was observed, and the mechanism of PESV to reverse the MDR of LSC was studied. At the same time, the expression of P-gp, MDR1 mRNA and PI3-K, NF-κB were respectively detected through flow cytometry, RT-PCR, Western blot and Elisa, and the mouse liver, spleen were examined via histopathological methods. The results of the experiment were as follows: mice of the control group didn't show any obvious changes, while mice of the other six groups all showed arched back, emaciation, liver swell, and inflammation was found in all liver tissue. The expression level of P-gp and PI3K on the LSC membrane of mouse tumor block was down-regulated; the expression of MDR1 mRNA in the cytoplasm was obviously down in the PESV low dose group, and which was inordinately up in the middle dose group and the high dose group. The expression level of NF-κB in the leukemia stem cell nucleus remarkably decreased. PESV had a outstanding role of down-regulating PI3K, NF-κb, MDR1 which were all upstream factors of P-gp, and to a certain degree enhanced the sensitivity of LSC to ADM. Therefore, this experiment explained one of the mighty mechanism of PESV to reverse MDR of LSC, and provided a foundation to further study of combinational anti-cancer effects of PESV.