The Investigation Of HER2 And FASN Regulate The Malignant Phenotype Of Ovarian Cancer And Its Molecular Mechanism

[Background and Purpose]Ovarian cancer is a common cancer of female reproductive organs, and the incidence of which is the third after cervical cancer and cancer of the uterus. The mortality of Ovarian cancer is accounted for first place, posing a serious threat to women’s lives, so for the molecular pathogenesis of ovarian cancer research is one of hot research gynecological tumor. In recent years, the manuscript has been reported:in the development of cancer, FASN and HER2 are thought to be very important, which could control the development of cancer alone or combination, which may be through the PI3K/Akt signal pathway. What the mechanism of the PI3K/Akt signaling pathway mediated by FASN and HER2 interaction in the development of ovarian cancer has not be reported..In this study, we will explore the relationship between FASN and HER2 expression and clinical pathology of ovarian cancer, and to further study the cross talking of PI3K/Akt signal pathway mediated FASN and HER2 interaction in the development of ovarian cancer combining with the research of molecular biology and cellular levels to provide experimental and theoretical basis for molecular targets and new for the diagnosis of ovarian cancer.[Methods]1. The ovarian cancer specimens were collected in Gulou Hospital of Nanjing University, which were confirmed by pathology and the patients without preoperative chemotherapy. The expression of FASN and HER2 were detected by tissue microarrays and the further analysis was done for the relationship in ovarian cancer and patient survival time and so on.2. The gene and protein expression of HER2 and FASN was detected by QPCR and Western Blot in the human ovarian cancer SKOV3, SKOV3/DDP and A2780.3. The interference plasmids of HER2 and FASN were ordered, which were transfected into the ovarian cancer cell line with high expression of HER2 and FASN. Then the high efficient interference plasmid was selected and the stable transfected interference plasmid of FASN and HER2 in the ovarian cancer cell line cell was established.4. In the target ovarian cancer, the expression of HER2 and FASN were detected by QPCR and Western Blot, and the cell proliferation, invasion and apoptosis protein were also detected. And further, the PI3K/Akt signaling pathway related proteins was detected.5. The suitable concentration of specific PI3K inhibitor ZSTK474 was choose to handle the ovarian cancer cell line for some time and some associated gene and protein were detected such as PI3K/Akt signaling pathway protein, HER2 and FASN gene and protein expression to explore the relationship among them.6. To observed the changes of cell cycle, apoptosis, and colony formation and invasion in the target ovarian cancer cell treatment with ZSTK474[Results]1. In the Human ovarian cancer tissues, the positive rate of FASN and HER2 is 70.5%(67/95) and 34%(32/95). There is significant difference between high expression of FASN and cancer grade and FIGO grade (P<0.05), but there is no significant difference between expression of HER2 and cancer grade and FIGO grade and so on (P>0.05). For more analysis, there is more poor prognosis in the group which were high expression of FASN and HER2.2. In the human ovarian cancer cell SKOV3, SKOV3/DDP and A2780, HER2 and FASN mRNA and protein expression were high in the A2780 than the other cells and the A2780was choose as the target cells.3. The high quality of interference plasmid of HER2 and FASN and the empty plasmid were transfected into A2780 cells to establish stably transfected cell line A2780. In the HER2 RNAi and FASN RNAi group, HER2 and FASN mRNA expression and protein expression were both significantly reduced compared with the control group (P<0.05). And the colony formation rate and cell invasion were also significantly reduced and apoptotic protein Bax was significantly induced, comparing with the control group (P<0.05).4. Further studies showed that, the PI3K/Akt pathway activity was significantly inhibited in the A2780 cells with HER2 RNAi and FASN RNAi plasmid.5. ZSTK474 could significantly reduce the activity of PI3K/Akt signaling pathway on the A2780 cells and the gene and protein expression of HER2 and FASN were also significantly suppressed compared with the control group (P<0.05)6. ZSTK474 could inhibit A2780 in the G1 phase and reduce its aggregation in the S phase. And the apoptosis of A2780 was significantly increased comparing with the control group (P<0.05). In addition, the results of the biological behavior showed that ZSTK474 could significantly reduce the clone formation rate and cell invasion of A2780, compared with the control group (P<0.05).[Conclusion]1. There is negative correlation-ship between the high expression of FASN and HER2 and the overall survival and prognosis in patients with ovarian cancer.2. The expression of HER2 and FASN in the A2780 cells were effectively knockdown through the transfection of HER2 RNAi and FASN RNAi and malignant biological behavior such as the colony formation rate and cell invasion were significantly reduced, which means that maybe there is a positive feedback regulation between HER2 and FASN.3. ZSTK474 could effectively inhibit the activity of PI3K/Akt pathway in A2780 cells. In the meanwhile, gene and protein expression of HER2 and FASN were also significantly reduced, and the malignant behavior of A2780 cells was also reduced.The results suggest that, the malignant phenotype of ovarian cancer could be regulated through the reaction of HER2, FASN and PI3K/Akt signaling pathway, which maybe play an important role in the development, invasion and metastasis of ovarian cancer...