HIF-1α及PI3K/Akt信号通路在中耳胆脂瘤中的表达及意义

Expression and significance of PI3K/Akt/HIF-1αpathway in middle ear cholesteatoma

目的探讨PI3K/Akt在通路在中耳胆脂瘤中的表达及意义。方法通过免疫组化检测胆脂瘤组织中HIF-1α的表达;Spearman相关性分析HIF-1α与胆脂瘤患者骨质破坏程度的相关性。同时培养胆脂瘤原代细胞(MEC),检测缺氧条件下MEC增殖速度的改变及给予PI3K/Akt通路抑制剂对MEC增殖的影响;Western blot检测PI3K/Akt抑制剂对HIF-1α及PI3K/Akt通路关键蛋白磷酸化的影响。结果胆脂瘤中HIF-1α的表达为(++)及(+++)细胞比例明显高于对照组(P<0.05);胆脂瘤骨质破坏程度与HIF-1α的表达呈正相关(P=0.012)(r值=16.286);缺氧条件促进MCE增殖,LY294022在缺氧条件下抑制MEC的增殖;缺氧条件下HIF-1α、p-PI3K蛋白及p-Akt蛋白308、492位点都出现不同程度的升高。而给予LY294002干预后,p-PI3K及p-Akt-308、492位点及HIF-1α被明显抑制。结论PI3K/Akt信号通路在缺氧条件下调节胆脂瘤细胞的增殖,对HIF-1α具有正向调节作用;通过抑制PI3K/Akt信号通路可以减缓胆脂瘤的增殖速度,其可能机制是PI3K/Akt通路通过下调HIF-1α的表达而实现的。

Objective To investigate the expression and significance of PI3K/Akt/HIF-1αpathway in middle ear cholesteatoma.Methods The expression levels of HIF-1αin cholesteatoma tissues were detected by immunohistochemistry.Spearman correlation was used to analyze the correlation between HIF-1αand bone destruction in patients with cholesteatoma.At the same time,cultured cholesteatoma primary cells(MEC)were used to detect the change of MEC proliferation rate under hypoxia and the effects of PI3K/Akt pathway inhibitor on MEC proliferation,Moreover the effects of PI3K/Akt inhibitors on the phosphorylation of key proteins in HIF-1αand PI3K/Akt pathway were detected by Western Blot.Results The expression levels of HIF-1αin cholesteatoma tissues were(++)and(+++)of cell proportion,which were significantly higher than those in control group(P<0.05).The degree of bone destruction in cholesteatoma was positively correlated with the expression of HIF-1α(P<0.05),and hypoxia condition promoted MCE proliferation,LY294022 inhibited MEC expression under hypoxia.Moreover hypoxia-inducible factors including HIF-1α,p-PI3K protein and p-Akt protein in 308,492 locus had increasing at different extents.After LY294002 intervention,p-PI3K and p-Akt-in 308,492 locus and HIF-1αwere significantly inhibited.Conclusion The PI3K/Akt signaling pathway can regulate the proliferation of cholesteatoma cells under hypoxic conditions,which has a positive regulatory effect on HIF-1α.By inhibiting the PI3K/Akt signaling pathway,the proliferation rate of cholesteatoma is decreased,and its action mechanism may be that the PI3K/Akt pathway is achieved by down-regulating the expression of HIF-1α.