ABSTRACT
Objective Ginsenoside Rh2 can inhibit the proliferation of a variety of malignant tumor cells.However, little research has been done on the sensitivity of Rh2 in human hepatocellular carcinoma HepG2/ADM cells with multidrug resistance(MDR).This study aimed to explore the reversing effects of ginsenoside Rh2 on the MDR of human hepatocellular carcinoma HepG2/ADM cells and its potential mechanism.Methods MTT assay was applied to detect the effect of Rh2(0-250 μg/mL) on the viability of HepG2/ADM cells and screen out the optimum drug-resistant reversal concentration of Rh2.Cells were divided into 3 groups: HepG2/ADM group (without any medicine treatment), ADM group(ADM treatment for 48 h), ADM+40 μg/mL Rh2 group (pretreatment of 40μg/mL Rh2 for 30 min followed by ADM treatment for 48 h).Flow cytometry was applied to detect the effect of Rh2 on the fluorescence intensity of cellular Rh-123.RT-PCR was used to measure the expression of MDR1 gene.Western blot was used to detect the protein levels of P-gp, Bax, Bcl-2 and cleaved caspase-3.Results 40 μg/mL ginsenoside Rh2 significantly reversed the MDR of HepG2/ADM cells by a 2.55-to-3.70-fold increase in sensitivity.Furthermore, compared with ADM group, the efflux of Rh-123 in HepG2/ADM cells were remarkably inhibited by Rh2 in ADM+40 μg/mL Rh2 group (65.83±1.78 vs 78.21±1.26, P<0.01), along with the down-regulated expressions of MDR1 (0.48±0.02 vs 0.86±0.05, P<0.05), P-gp(0.97±0.04 vs 1.91±0.03,P<0.01), Bcl-2(1.25±0.05 vs 1.86±0.03, P<0.05) and the up-regulated protein level of Bax (1.76±0.04 vs 1.25±0.02,P<0.05) and cleved caspase-3(0.42±0.04 vs 38.26±5.45,P<0.05).Conclusion Ginsenoside Rh2 can effectively reverse the MDR of HepG2/ADM cells, and the potential mechanism is related to the decreased expressions of MDR1 and P-gp, the increasing drug concentration inside the cells and the Bax/Bcl-2 signaling pathway.
ABSTRACT
OBJECTIVE: Resistant, recurrent ovarian cancer patients who had first chemotherapy with Cisplatin have showed low reactivity and high recurrence in the secondary chemotherapy. Therefore, multi-drug resistance (MDR) to chemotherapy is a major obstacle in attempts to improve the clinical outcome of ovarian cancer patients. The aim of our study is to analyze the sensitivity of some chemotherapy drugs when we co-use Cyclosporine A (CsA), which suppresses MDR, in the secondary drug resistant cell line. METHODS: After establishing the secondary drug resistant cell line, drug sensitivity was measured by MTT assay. MDR gene and protein were analyzed by RT-PCR and western blotting assay. RESULTS: MDR gene (MDR1) and protein (P-gp) were overexpressed in the secondary drug resistant cell line. When we measured the sensitivity of some chemotherapy drug after using the amounts of CsA that can suppress MDR1/P-gp, the sensitivity of Paclitaxel was highest. CONCLUSION: CsA has a role that makes the sensitivity of chemotherapy drug higher in the secondary drug resistant cell line by suppression of multi-drug resistance. Therefore, we could expect that the proper use of MDR suppresser like CsA with secondary chemotherapy drug would help to cure resistant, recurrent ovarian cancer patients.