Reversal effect of Stephania tetrandra-containing Chinese herb formula SENL on multidrug resistance in lung cancer cell line SW1573/2R120.

This research is aimed on reversing multidrug resistance (MDR) of chemotherapy in lung cancer. According to our previous research, chemotherapeutic drugs resistance in lung cancer is mainly due to high expression of multidrug resistance-associated protein (MRP) gene and activation of caspases. The effect of stephania tetrandra-containing Chinese herbal formula, namely Supplement Energy and Nourish Lung (SENL), is effective in enhancing efficacy and reducing toxicity of chemotherapy in lung cancer. However, the underlying mechnism is largely unknown. To understand whether and how SENL herbs function on multidrug-resistance lung cancer cells, we treated a multidrug resistance lung cancer cell line, SW1573/2R120 with SENL herbs alone or together with a chemotherapeutic drug, Adriamycin (ADM). We observed that SENL herbs had a significant synergistic effect with ADM in inhibiting the growth of SW1573/2R120 cells. SENL alone and particularly together with ADM could significantly increase cell apoptotic death via mitochondria- and caspase-dependent pathway. Furthermore, we showed that SENL herbs could reverse drug resistance of lung cancer cells by decreasing MRP expression and increasing accumulation of intracellular ADM, which in turn increase the sensitivity of cancer cells to ADM. Taken together, the mechanism underlying reversal effect of drug resistance by SENL treatment was reported here and further systematical investigation on SENL herbs may lead to solve drug resistance in lung cancer chemotherapy.