ABSTRACT
Aim To investigate the effect of indirubin derivative PHⅡ-7 and TRAIL on proliferation in breast cancer cell MCF-7 and its MDR counterpart MCF-7/ADR and the mechanism.Methods Growth inhibition rate was examined respectively by MTT assay under treatment with TRAIL or PHⅡ-7 or in combination. Cell apoptosis and ROS production were examined by flow cytometry.The change of TRAIL receptors(DR4/DR5 )in mRNA was analysed by realtime PCR.Re-sults IC50 of PHⅡ-7 on MCF-7 and MCF-7/ADR was (4.49 ±1.55 ),(3.44 ±0.90 )μmol · L-1 respec-tively;MDA-MB-231 was TRAIL sensitive cell line, and apparently TRAIL induced apoptosis in MDA-MB-23 1 .Low concentration of PHⅡ-7 in combination with TRAIL could augment TRAIL-induced cytotoxic effect including apoptosis while TRAIL or PHⅡ-7 treatment alone had limited cytotoxity to those cells.Besides, PHⅡ-7 at this concentration had little toxicity to hu-man peripheral blood mononuclear cells even if in com-bination with TRAIL.PHⅡ-7 generated ROS produc-tion inside MCF-7 and MCF-7/ADR cells and up-regu-lated DR4/DR5 expression concentration dependently. Once upon ROS scavenger NAC involved,the effect of TRAIL receptors up-regualtion by expression was abro-gated.Conclusions PHⅡ-7 at low concentration could improve the sensitivities of breast cancer cell MCF-7 and MCF-7/ADR to TRAIL,the mechanism of which may be the ability of ROS production by PHⅡ-7 help up-regulated TRAIL receptor DR4,DR5 .Our re-search set a solid foundation for PHⅡ-7 in combination with TRAIL in future clinical application.
ABSTRACT
Background and purpose:Multidrug resistance(MDR)is one of the major causes of progressive breast cancer chemotherapy failure.One of the major mechanisms of MDR is the overexpression of P-glycoprotein (P-gp).Therefore,the identification of novel agents which can inhibit the drug transporter function of P-gp or its expression is of utmost interest in cancer research.The aim of this study was to explore the antitumor and reversal effect of PHⅡ-7,natural products from traditional Chinese medicine(TCM).Methods:The cytotoxicity of PHⅡ7 alone and combined application of PHⅡ-7 and adriamycin(ADR)on breast cancer cells were determined using MTT assay.Annexin V–FITC/PI apoptosis detection kit was used to observe the apoptosis-inducing effect of PHⅡ-7 in MCF-7 and MCF-7/ADR cells.The effect of PHⅡ-7 on mdr1 mRNA was determined by reverse transcription PCR and real time PCR,flow cytometer was used to measure the intracellular ADR accumulation.Results:PHⅡ-7 alone inhibited cell growth of MCF-7 and MCF-7/ADR cells with the IC 50 (6.07?0.85),(5.51?1.22)?mol/L,respectively when combined with ADR,PHⅡ-7 enhanced the cytotoxicity of ADR toward MCF-7/ADR cells.In addition,PHⅡ-7 induced apoptosis both on MCF-7 and MCF-7/ADR cells;PHⅡ-7 reversed the drug resistance to ADR in MCF-7/ADR cells by inhibiting mdr1 mRNA transcription and increasing the intracellular ADR accumulation.Conclusion:PHⅡ-7 displayed significant anti-proliferative and apoptosis-inducing effect on sensitive and multidrug resistant breast cells in vitro.PHⅡ-7 reversed effectively MDR by blocking the drugs to be pumped out by inhibiting P-gp expression and function pathway.
ABSTRACT
Aim To study the mechanism of anti-tumor effect of PHⅡ-7 to K562 and K562/A02 cells.Methods The effects of individual and combined doxorubicin on K562 and K562/A02 cells were observed by MTT assay.The coefficient of drug interaction was used to analyse the synergistic effect of PHⅡ-7,obtaining the RNA from the cells stimulated by PHⅡ-7 with different doses to analyse the MDR1 gene expression level.Finally,the cumulation of doxorubicin was observed in K562 and K562/A02 cells after being coped with PHⅡ-7.Results PH Ⅱ-7 had anti-tumor effect with IC50 of (1.37?0.37) ?mol?L-1;(1.48?0.34) ?mol?L-1 for K562 and K562/A02,respectively.It could potentiate the anti-tumor effect of dororubicin with CDI of 0.22 and 0.09 for K562 and K562/A02,respectively.PHⅡ-7 could synergistically inhibit the proliferation of K562 and K562/A02 cells.The decrease of MDR1 expression level depended on the increase of dose of PHⅡ-7 acting on cells.PHⅡ-7 could also develop the cumulation of doxorubicin in cells.Conclusion PHⅡ-7 is not only a Cytotoxinic drug but also can synergistically inhibit the proliferation of K562 and K562/A02 cells with the decrease of MDR1 expression level,especially in K562/A02 cells.