Tanshinone microemulsion reverses multidrug resistance of tumor

Changjian LIU; Jianguo LIU; Tiecheng YU

ABSTRACT

BACKGROUND:

Multidrug resistance (MDR) makes the treatment of tumor more difficult. Many factors contribute to the happening of MDR. The combination of two or more kinds of reverse reagent at the same time may be more effective to MDR.

OBJECTIVE:

To investigate the reversal effect of Tanshinone Microemulsion on MDR of human leukemia cell line (K562) and ADM resistant cell line (K562/ADM) cell line and the mechanism of it.

DESIGN:

An observational controlled experiment.

SETTING:

First Affiliated Hospital's Central Laboratory of Jilin University.MATERIALS K562 and K562/ADM (Tianjin Blood Research Institute of CAS). Tanshinone and Tanshinone Microemulsion (Pharmaceutical College of Jilin University). ADM(Pfizer pharmaceutical corp). P-gp-PE fluorescent antibody and Bcl-2-FITC fluorescent antibody (Immunotech Biotech corp).DMSO(Beijing Chemical Plant).

METHODS:

The experiment was carried out in the Central Laboratory of First Hospital ffiliated to Jilin University from March 2003 to January 2004. ① K562 was cultured in liquid medium(RMPI1640) which contains 100 g/L calf serum, 100 U/mL penicillin and streptomycin. The culture tank's environment was kept at 37 ℃, with saturated humidity and 5%CO2. K562/ADM was cultured in the same environment as above, but ADM was added to the RMPI1640. ② The reverse effect of Tanshinone Microemulsion (Tanshinone and Microemulsion as control) on K562/ADM cells' MDR is observed. ③Tanshinone Microemulsion,Tanshinone and Microemulsion's MDR reverse fold to K562 cell line was detected by the method of MTT. ④ ADM of different concentrations (10, 20, 40, 60 mg/L)were added to grouped cells of exponential proliferation period. The intracellular drug concentration was observed by detecting fluorescent density.⑤ Expression rate of P-gp, Bcl-2 and apoptosis ratio of K562 and K562/ADM added with Tanshinone Microemulsion, Tanshinone and Microemulsion cell line were observed by the method of Flow Cytometry.MAIN OUTCOME

MEASURES:

①Tanshinone Microemulsion, Tanshinone and Microemulsion's MDR reverse fold to K562 cell line. ②Tanshinone Microemulsion, Tanshinone and Microemulsion's effect to K562 cell's intracellular contration.③Tanshinone Microemulsion, Tanshinone and Microemulsion's influence to K562 cell's expression rate of P-gp, Bcl-2 and apoptosis ratio.

RESULTS:

①Tanshinone Microemulsion, Tanshinone and Microemulsion could decrease the MDR of the K562/ADM. The effect of Tanshinone Microemulsion were significantly higher than Tanshinone and Microemulsion(P ＜ 0.05 ).②The intracellular concentration of ADM can be improved by Tanshinone Microemulsion, Microemulsion and Tanshinone. The ADM's concentration of K562/ADM treated by Tanshinone Microemulsion is highest and the difference is significant(P＜ 0.05). ③Tanshinone Microemulsion, Tanshinone and Microemulsion could reduce the expression level of P-gp and Bcl-2 in K562/ADM, and increase the apoptosis percentage of tumor cell. Tanshinone Microemulsion has the most significant effect on it,andincreases the apoptosis percentage of tumor cell with ADM (P ＜ 0.05 ).

CONCLUSION:

Tanshinone Microemulsion (0.5 mg/L) can increase the intracellular concentration of ADM, which is consist with the conclusion of down regulation of the expressions of P-gp and Bcl-2. Reversal effect of Tanshinone Microemulsion is more effective than that of Tanshinone and Microemulsion.