Abstract: The objective of this study was to investigate the effects of CJD combined with Gefitinib on the protein expressions of twist,fibronectin and their mRNA in nude mouse xenografts models of H1975 human lung and to study its anti-tumor mechanisms from EMT.60 BALB/c mice were selected to establish lung cancer xenograft models with lung adenocarcinoma H1975 drug-resistant cells,which were randomly divided into six groups (n=10):control group,Gefitinib-treated group,CJD low-dose group,CJD middle-dose group,CJD high-dose group,and the combined medication group (CJD + Gefitinib-treated).Mice in each group were given intragastric administration with corresponding drugs for 2 weeks.The tumor size and tumor weight were detected.And the tumor inhibitory rates were calculated.The protein expressions of twist,fibronectin and their mRNA were detected by methods of immunohistochemistry,Western blotting and real-time PCR.Result:The tumor inhibitory rates of the combined medication group was 61.92%,which was higher than that of the control group,Gefitinib-treated group,CJD low-dose group,CJD middle-dose group and CJD high-dose group (P<0.01).The results of immunohistochemistry,Western blotting and Real-time PCR showed that the expressions of twist and fibronectin proteins and mRNA in CJD middle-dose group,CJD high-dose group and the combined medication group decreased significantly.And the combined medication group decreased than that of CJD or gefitinib alone(P<0.01).The inhibitory effect of CJD combined with gefitinib on the growth of the lung adenocarcinoma H1975 xenograft in nude mice and the protein and mRNA expression levels of twist and fibronectin is superior to that of CJD or gefitinib alone.The combination of the two can play a synergistic effect,and its possible mechanism maybe related to reverse EMT to enhance the sensitivity of gefitinib.

Key words: Chutan Jiedu Decoction, lung cancer, H1975, twist, fibronectin