Taken together, our data suggested that EGCG inhibits GC growth and reverses 5-FU resistance of GC through inactivation of TFAP2A/VEGF pathway and down-regulation of MDR-1 and P-gp expression.
Thus, we found that HIF-1α is closely associated with MDR in GC and that HIF-1α may suppress MDR1/P-gp, LRP and Bcl-2 expression by inhibiting miR-27a expression.
MTT assay, RT-PCR, Western blotting were employed to detect susceptibility of GC cells to chemotherapeutic agents (5-FU, L-OHP) in vitro, and expressions of ZNF139 and MDR associated genes MDR1/P-gp, MRP1, Bcl-2, Bax were also detected. siRNA specific to ZNF139 was transfected into MKN28 cells, then chemosensitivity of GC cells as well as changes of ZNF139 and MDR associated genes were detected.
These preliminary results indicate that the c.3073A>C genetic polymorphism of the MDR1 gene is potentially related to the susceptibility to gastric cancer in the Chinese Han population.
Multiple drug resistance 1/P-glycoprotein (MDR1/p-gp) contributes to drug resistance via ATP-dependent drug efflux pumps and is overexpressed in many solid tumors including gastric cancer.
The methylation of the MDR1 promoter was estimated in both antral non-neoplastic mucosa and cancer lesions in 83 patients with gastric cancer using a methylation-specific PCR method.
In this preliminary data, the association with MDR1C3435T polymorphism and risk for developing H. pylori-related gastric cancer and peptic ulcer in Japanese was low.
By introduction of anti-MDR1/P-gp shRNA expression vectors into the extremely high drug-resistant human gastric carcinoma cell line EPG85-257RDB, the MDR phenotype was completely reversed.
To detect the expression of glutathione S-transferase Pi(GST-pi), multidrug resistance-associated protein (MRP), lung-resistance protein(LRP), multidrug resistance gene1 (MDR1) and MGr1 antigen(MGr1-Ag) in the patients with primary gastric cancer and without any prior chemotherapy and to evaluate the correlations between them.