Reversal Of Multi-Drug Resistance In Laryngeal Carcinoma Of Tetrandrine

Malignant tumors have become serious life threating diseases . Chemical therapy is one of the most important treatment to cancer. However the effect of chemical therapy is not as good as we expected mainly because of multidrug resistance (MDR). So overcoming MDR becomes one of the major challenges to successful chemical therapy .Natrual substances are becoming a hot spots of the recent researches. Laryngocarcinoma is one of the most common cancers in ENT department, chemical therapy is an important method to treat its advanced stage, but the effect is not significant.Our early reseaches showed that natural substances oxymatrine(Oxy) and tea polyphenols ( TP ) had the effects of reversing MDR of Laryngocarcinoma and Nasopharyngeal carcinoma . This research continued to test the reversing effects of natural substance tetrandrine(TET)on Hep-2/ADM cell line and its possible mechanisms. .The Hep-2/ADM cell line was induced by increasing density of ADM on the Hep-2 cell line. MTT was used to test the drug sensity on the Hep-2/ADM cell line. Light microscope and electron microscope were used to describe the changing of morphous . Cell counting was used to test the growth curve of the both cell lines. Immunocytochemistry was used to test the expression of P-gp. Results showed :1. The MDR subline Hep-2/ADM were established after 6 months. MTT showed the resist Index(RI))was 13.29.2. Light microscope showed some slightly changes of the morphous. Electron microscope showed the microvillus were decreased.3. Cell counting showed a doubling time extension.4. Immunocytochemistry showed a P-gp positive.5. The Hep-2/ADM cell line had the MDR features. To test the reversal effects of TET on Hep-2/ADM cell line, MTT was used to test the reveral effects and Oxy,TP were used as contrasts . Results showed :1. MTT showed the no toxicity dose of TET on the Hep-2/ADM cell line were 1.0μg/ml和1.5μg/ml.2. The RF of TET (1.0μg/ml和1.5μg/ml) on Hep-2/ADM cells against DDP were 1.72,2.00 .3. The RF of TET (1.0μg/ml和1.5μg/ml) on Hep-2/ADM cells against 5-Fu were 2.63,3.19 .4. The RF of TET (1.0μg/ml和1.5μg/ml) on Hep-2/ADM cells against VCR were 3.87,4.66 .5. The RF of TET (1.0μg/ml和1.5μg/ml) on Hep-2/ADM cells against ADM were 2.02,2.23 .6. The reversal effects of TET were better than that of Oxy and TP in this research.To test the possible mechanisms that the TET's reversal effects based on , Immunocytochemistry was used to test the expression of P-gp. Flow cytometry was use to test the fuction of P-gp , results showed:1. No significant changes of the expression of P-gp were found by Immunocytochemistry.2. The results of Flow cytometry showed a depression of the P-gp function .So TET had the effect of reversing MDR on the Hep-2/ADM cell line and the possible mechanism was the depression of the P-gp function.This research considered the establishment of MDR cell model, the MDR reversal effects of TET ,the expression of P-gp and the function of P-gp as a whole . Discussed the MDR reversal effects of TET on the human laryngocarcinoma MDR cell line Hep-2/ADM and its possible mechanisms , provided laboratory evidence of further researches of Chinese herb on reversing MDR .