Acacetin inhibited HIF 1 expression by affecting its destruction To determine whether acacetin inhibits HIF 1 expression at transcriptional level, OVCAR 3 and A2780 cells were treated with various doses of MAPK pathway acacetin for 6 h and HIF 1 mRNA was examined by RT PCR. As shown in Fig. 3A, acacetin treatment did not reduce HIF 1 mRNA levels, suggesting that acacetin did not prevent HIF 1 expression at transcriptional level. We next determined the effect of acacetin on the balance of HIF 1 protein by using cycloheximide treatment to inhibit new protein synthesis in the cells. A2780cells and ovcar 3 were handled with CHX or CHX plus acacetin to get a different time period. The degrees of HIF 1 protein were detected by immunoblotting, and normalized to those of W actin within the cells. The general half life of HIF 1 protein in the cells was determined. The half life of HIF 1 was 4. 2 min and 5. 2 min in OVCAR 3 and A2780 cells, respectively, while in the presence of CHX alone, and was decreased to 1 and 2 min. 4 min, respectively with the treatment of acacetin, suggesting that acacetin treatment somewhat Infectious causes of cancer increased HIF 1 protein degradation. 3. 5. Acacetin inhibited ovarian tumor angiogenesis, tumor development, and HIF 1 and VEGF expression in vivo The aforementioned confirmed that acacetin inhibited VEGF and HIF 1 expression. Given the key roles of VEGF and HIF 1 in regulating tumor development and angiogenesis, we used chicken chorioallantoic membrane model to test the result of acacetin on tumor angiogenesis. The showed that acacetin therapy significantly inhibited tumor angiogenesis. The micro vessel density was reduced by acacetin therapy to 5000-10,000 of the get a handle on, demonstrating that acacetin inhibited ovarian cancer cells stimulated angiogenesis in vivo. To further check whether acacetin inhibited tumefaction development, OVCAR 3 cells were implanted to the CAM in the absence or price PCI-32765 presence of acacetin to develop tumors for 9 days. As shown in Fig. When comparing to that from the control group, indicating that acacetin suppresses tumor growth through impeding the angiogenesis 4b, acacetin therapy inhibited tumor growth with 500-million decrease of tumor weight. Consistent with the of in vitro studies, acacetin inhibited the VEGF expression in tumefaction tissue samples and degrees of HIF 1. These declare that acacetin has strong influence to inhibit tumor growth and angiogenesis. 4. VEGF may be the most significant inducer of tumefaction angiogenesis. The increased degree of VEGF is correlated with angiogenesis and bad prognosis in cancer, showing the essential role of VEGF in development and tumor angiogenesis. Tumor development and metastasis require angiogenesis once the tumor reaches 1 2 mm in diameter. Inhibition of angiogenesis especially suppresses cyst growth and invasion without affecting the standard mature vessels in body. Ergo, there are increasing interests in developing anti angiogenesis ways for human cancer therapy. Acacetin shows inhibitory impact on cell proliferation, cell cycle progression, induces cell apoptosis in vitro, and suppresses migration and invasion of cancer cells.