Study On The Effect Of Apoptosis Induction And The Mechanism Of Drug-resistance Reserved By Compound Angelica Injection In Leukemic K562 Cell Line

Object:Using flow cytometry and Western-blot analysis to detect the effect of compound angelica injection, brucine and strychnine on the apoptosis induction and expression of bcl-2 protein in leukemia cells, exploring the underlying drug–reversed mechanisms of these agents.Method:Cell lines K562/A02 and K562 were treated with etoposide and its cytotoxic effect detected by MTT colorimetric assay. Cell apoptosis percentage and the expression level of bcl-2 protein after different time course of compound angelica injection, brucine and strychnine at the dose level of IC10(our previous research supplied)along with etoposide singly or combined used were determined by flow cytometry and western-blot analysis respectively.Results:1. Etoposide could inhibit the proliferation of K562/S cells and K562/A02 in a dose dependent manner and the concentration of 1μg.ml^-1 and 40μg.ml^-1 before 50% inhibitory rate was chosen. 2. Non-cytotoxicity concentration of compound angelica injection, brucine and strychnine administered individually for 24h, 48h and 72h, the apoptotic rate of K562/A02 cells slightly increased after different time course and there was a statistics significance(P<0.05) for compound angelica injection at 72h When combined with etoposide 40μg.ml^-1, these agents markedly improved apoptosis rate in a manner depending on time.3. Non-cytotoxicity concentration of these Chinese traditional medicine had no obvious influence on the expression of bcl-2 protein of K562/A02 cells at different time course. After incubated with etoposide 40μg.ml^-1, the expression of bcl-2 was decreased, especially compound angelica injection in proportion to the time course added.4. The tested agents could prompt the effect of etoposide-induced apoptosis and down-regulate the expression of bcl-2 protein.Conclusion:1. Compound angelica injection, brucine and strychnine could partially reverse multidrug resistance (MDR) in leukemia cells.2. These agents overcome MDR associated with the enhancement of etoposide in inducing K562/A02 apoptosis by weakening the expression of bcl-2 protein.