Study On The Effects Of Melatonin Nuclear Receptor Targets Based On Angiogenesis In Gastric Carcinoma

Gastric cancer is one of the most common malignancies in China, and characterized by a rapid progression, shorter survival and poor prognosis. How to improve the survival rate of gastric cancer remains a major clinical challenge currently. Tumor growth, metastasis and prognosis are associated with angiogenesis.Angiogenesis is a multifactorial multi-step process. Blocking any further process will prevent tumor angiogenesis. Therefore, blocking tumor angiogenesis system has become a new target for anti-tumor therapy. In recent years, numerous studies have demonstrated anti-tumor effects of melatonin. Melatonin nuclear receptors may be an important way which play a role in anti-tumor. The relationships among melatonin,melatonin nuclear receptors, and gastric cancer angiogenesis have not been published. Our study aimed at investigating the relationships of melatonin inhibition of gastric cancer angiogenesis and nuclear melatonin receptor in the hypoxic conditions, which provides new ideas and accesses for the treatment of gastric cancer biology and lays the foundation for application development solid foundation.1 The anti-angiogenic function of melatonin in the human gastric cancer cells and the effect on melatonin nuclear receptor in vitroIn order to the study of melatonin anti-angiogenic effect in human gastric cancer cells and its effect on melatonin nuclear receptors in vitro.This part of the study to establish the time point at different concentrations of melatonin on human gastric cancer cell lines intervention model.CCK-8, ELISA, real-time quantitative RT-PCR,Western blot were used to detect human gastric cancer cell proliferation and m RNA and protein expression changes of VEGF, Angiopoietin, Angiostatin, melatonin nuclear receptor. The results showed that :(1)CCK-8 showed that melatonin inhibits proliferation of human gastric cancer cells, MGC-803, SGC-7901, and AGS, with dose and time dependent; Chemical hypoxiapromotion simulated by 100μmol/L cobalt chloride(Cobalt Chloride, Co Cl2) can increase proliferation of human gastriccancer SGC-7901 cells;(2) High concentrations of melatonin can decrease the expression of VEGF m RNA and protein of human gastric cancer cell SGC-7901;(3)High concentrations of melatonin can decrease the expression of nuclear receptor RZR/RORγ m RNA and protein of human gastric cancer cell SGC-7901.2 The anti-angiogenic mechanism of melatonin in human gastric cancer cells SGC-7901 in vitro and the research of melatonin nuclear receptor RZR/RORγtargets.In order to study the roles of SENP1, HIF-1α, VEGF in melatonin-mediated inhibition of angiogenesis in vitro, we performed a cell model by human gastric cancer cell SGC-790 treatment with 3 m M concentrations melatonin in this section and Chemical hypoxiapromotion simulated by 100μmol/L cobalt chloride(Cobalt Chloride, Co Cl2). The method of si RNA were performed to silence RZR/RORγexpression to explore inhibitive roles of the signaling pathway on gastric cancer cell proliferation. The results showed that :(1)Si RNA-mediated the RZR/RORγ silent significantly antagonized the inhibitory effect of melatonin on gastric cancer cell proliferation. This result suggested that the effect of melatonin on promoting tumor cell inhibiting tumor cell proliferation may be associated with melatonin nuclear receptor RZR/RORγ;(2)Hight concentration melatonin reduced significantly the SGC-7901 m RNA and protein expression of nuclear receptor RZR / RORγ、 SENP1、HIF-1α and VEGF after the intervention 24 h in the hypoxic conditions;(3)Silence nuclear receptor RZR/RORγ antagonized significantly increased the m RNA and protein expression of SENP1, HIF-1α, VEGF, which suggested that melatonin inhibited gastric cancer angiogenesis effect through nuclear receptor RZR / RORγ.3 The anti-angiogenic mechanism of melatonin on the gastric cancer nude mice in vivoIn order to study the anti-angiogenic role of nude mice gastric carcinoma of melatonin and the relationship between melatonin with RZR/RORγ in vivo, the tumor-bearing nude mice model of gastric cancer was established from human gastric cancer cells SGC-7901 in this part of the research. The expression changes of related factors were detected by immunohistochemistry, real-time fluorescence quantitative PCR and western blot after the intervention of different concentrations of melatonin.The results showed that:(1)Melatonin reduced the tumor volume and the tumor weight of the gastric cancer-bearing nude mice and reached the anti-tumor effect;(2)Melatonin inhibited tumor proliferation and tumor angiogenesis by down-regulation the expression of melatonin receptor nuclear RZR / RORγ 、SENP1 、HIF-1α、 VEGF and MVD;(3)The fact that melatonin down-regulation the expression of nuclear receptor RZR/RORγ expression in tumor tissues of the gastric cancer-bearing nude mice indicated that the function of anti-angiogenesis may be thought nuclear receptor RZR/RORγ.In summary, the experiments confirmed that melatonin can inhibit gastric cancer angiogenesis in vivo and in vitro. The mechanism of inhibition gastric cancer angiogenesis include suppression the expression of SENP1、HIF- 1α、VEGF through nuclear receptor RZR/RORγ. Thereby melatonin nuclear receptor RZR/RORγ play a important role in the inhibiting tumor angiogenesis and tumor growth.