RESULTS: The results showed that exogenous 8-Bromoguanosine-3\', 5\'-cyclic monophosphate (8-Br-cGMP) (cGMP analog) could antagonize the effects by EGF, including suppressing proliferation, invasion and migration of EOC cells. In vivo, 8-Br-cGMP hampered the growth of the xenograft tumor. Additionally, the expressions of epidermal growth factor receptor (EGFR), matrix metallopeptidase 9 (MMP9), proliferating cell nuclear antigen and Ki67 in xenograft tumor were decreased after 8-Br-cGMP intervention. Further research demonstrated that 8-Br-cGMP decreased the phosphorylation of EGFR (Y992) and downstream proteins phospholipase Cγ1 (PLC γ1) (Y783), calmodulin kinase II (T286) and inhibited cytoplasmic Ca2+ release as well as PKC transferring to cell membrane. It\'s worth noting that the inhibition was 8-Br-cGMP dose-dependent and 8-Br-cGMP showed similar inhibitory effect on EOC cells compared with U-73122, a specific inhibitor of PLC γ1.
CONCLUSIONS: The activation of endogenous PKG I by addition of exogenous 8-Br-cGMP could inhibit EOC development probably via EGFR/PLCγ1 signaling pathway. 8-Br-cGMP/PKG I provide a new insight and strategy for EOC treatment.
结果:结果表明,外源8-溴鸟苷-3',5'-环单磷酸酯(8-Br-cGMP)(cGMP类似物)可以拮抗EGF的作用,包括抑制增殖,EOC细胞的侵袭和迁移。在体内,8-Br-cGMP阻碍了异种移植肿瘤的生长。此外,表皮生长因子受体(EGFR)的表达,基质金属肽酶9(MMP9),8-Br-cGMP干预后,异种移植瘤的增殖细胞核抗原和Ki67降低。进一步研究表明,8-Br-cGMP降低了EGFR(Y992)和下游蛋白磷脂酶Cγ1(PLCγ1)(Y783)的磷酸化,钙调蛋白激酶II(T286)并抑制细胞质Ca2释放以及PKC向细胞膜的转移。值得注意的是,这种抑制作用是8-Br-cGMP剂量依赖性的,与PLCγ1的特异性抑制剂U-73122相比,8-Br-cGMP对EOC细胞具有相似的抑制作用。
结论:通过添加外源性8-Br-cGMP激活内源性PKGI可能通过EGFR/PLCγ1信号通路抑制EOC的发展。8-Br-cGMP/PKGI为EOC治疗提供了新的思路和策略。