Silencing GRP94 By RNAi Effect Biological Characteristics Of Breast Cancer MCF7 Cells

ObjectiveBreast cancer is one of the most serious malignant tumors which are threat to women's physical and mental health. Its incidence shows a rising trend. Although in recent years the study of breast cancer at the molecular level were more in-depth and found a variety of factors and signaling pathways involved in the occurrence and development of breast cancer. Its pathogenesis is still unclear, and the study of breast cancer-related molecules is still one of the hot current researches.Glucose-regulated protein 94(GRP94) is mainly stored in the endoplasmic reticulum chaperone. It has 50% homology with HSP90. It involves in the endoplasmic reticulum stress response and it is a key to the unfolded protein response downstream molecules. Previous study found that GRP94 is over-expressed in many tumors, such as colon cancer, pancreatic cancer, esophageal cancer and breast cancer etc. Furthermore, GRP94 was involved in tumorigenesis and development. And the study of its mechanisms is an important issue currently. This subject examined the expression of GRP94 in breast cancer cells, and knockdown the expression of GRP94 by RNAi. And then we observed the effect of knocking down GRP94 on breast cancer cell proliferation, apoptosis and invasion and migration, and the underlying mechanism. It is contribute to investigate the relationship between GRP94 and the tumorigenesis and development of breast cancer, and provides theoretical basis for the prevention and treatment of breast cancer.In this study, we knocked down GRP94 expression to explore the links with Wnt/?-catenin signaling pathway, and thus to explain the important role in breast cancer tumorigenesis and development.Methods1. Respectively, mRNA and protein levels of GRP94 expression in mammary epithelial cells MCF10A, breast cancer MCF7, MDA-MB-231, BT474 and SK-BR-3 cell lines were detected by Real-time PCR and Western blot.2. Knock down the expression of GRP94 was used by siRNA in MCF7 breast cancer cell lines and observed the effect of cell proliferation, apoptosis, migration and invasion in MCF7 cells. Western blot were used to detect the related molecules expression.3. Western blot were used to detect the expression of key molecules in Wnt/?-catenin signaling pathway.Result1. The results showed that GRP94 expression was significantly increased in breast cancer cells, and the highest in MCF7 (P<0.05).2. When silencing the expression of GRP94, cell cycle arrest at G1/S phase, cell growth, colony-forming and cell invasion ability were significantly inhibited, and promote cell apoptosis. Related molecules expression of MMP2, MMP9, VEGF levels were decreased, E-cadherin expression was significantly increased, and the differences were statistically significant (P<0.05).3. After silencing GRP94 expression, the results of Western blot showed that LRP6 expression was significantly decreased, APC and AXIN expression increased, Wnt/?-catenin signaling pathway was blocked. The expression of nucleus and cytoplasm ?-catenin levels were reduced, suggesting that nuclear translocation of ?-catenin was suppressed.Conclusion1. GRP94 expression is significantly increased in breast cancer cells, and the highest in MCF7.2. When knocking down the expression of GRP94, cell proliferation, invasion and migration are significantly inhibited, and promote cell apoptosis in breast cancer MCF7cells.3. The expression of silencing GRP94 can block Wnt/?-catenin signaling pathway, inhibit ?-catenin nuclear translocation and the regulation of downstream target genes expression.