LncRNA HOTAIR通过COX-2调控胃癌细胞增殖与侵袭

LncRNA HOTAIR modulates the proliferation and migration of gastric cancer cells via COX-2 expression

目的:研究长链非编码RNA(long non-coding RNA,lnc RNA)HOX转录反义RNA(HOX transcript antisense RNA,HOTAIR)对胃癌细胞增殖、侵袭能力的影响及其相关分子机制。方法:培养人胃黏膜上皮细胞株(GES-1)和胃癌细胞株(SGC7901和MKN45),实时荧光定量PCR(q RT-PCR)法检测HOTAIR表达,MTT法检测胃癌细胞增殖,细胞划痕实验、Transwell小室检测细胞迁移和侵袭;免疫印迹法分析COX-2及上皮间质转化(epithelial-mesenchymal transition,EMT)相关标志物E-钙黏素(E-cadherin)表达。结果:与GES-1相比,SGC7901和MKN45细胞中HOTAIR表达上调(P<0.05);敲减HOTAIR基因能抑制胃癌细胞增殖、迁移与侵袭(P<0.01);胃癌细胞HOTAIR表达下调后COX-2蛋白水平降低,进而使E-cadherin蛋白水平升高(P<0.05),且该效应可被外源性COX-2活性产物前列腺素E2(prostaglandin E2,PGE2)所纠正。与HOTAIR敲减组相比,HOTAIR敲减+PGE2组细胞增殖、迁移及侵袭能力明显升高。结论:下调HOTAIR可能通过抑制COX-2表达,进而上调E-cadherin表达,抑制胃癌细胞增殖和侵袭转移能力,有望成为治疗胃癌的重要靶点。

Objective：To investigate the potential effects of long non-coding RNA（lnc RNA）HOX transcript antisense intergenic RNA（HOTAIR）on proliferation,invasion and metastasis capacity of gastric cancer cells and to reveal the underling mechanisms.Methods：Human gastric epithelial cell line（GES-1）and different gastric cancer cell lines（SGC7901 and MKN-45）were cultured respectively. SGC7901 cancer cells were transiently transfected with small interfering RNA targeting HOTAIR（si HOTAIR）,q RT-PCR was conducted to assess HOTAIR expression. MTT assay was carried out to evaluate the cell proliferation,wound-healing assay as well as transwell matrix invasion assay was performed respectively to evaluate the capability of invasion and migration of gastric cancer cells. The expression of cyclooxygenase-2（COX-2）,together with E-cadherin was detected by Western blot assay. Results：The expression of HOTAIR in gastric cancer cells was higher than that in GES-1 cells（P 0.05）. The cell proliferation was significantly inhibited after HOTAIR knockdown（P 0.01）. Both wound healing assay and transwell assay demonstrated that HOTAIR knockdown resulted in a lower ratio in migration and invasion. Western blot analysis revealed that depletion of HOTAIR substantially decreased the expression of COX-2,and then elevated the expression of E-cadherin（P 0.05）,this effect would be attenuated by exogenous prostaglandin E2（PGE2）. Compared with si HOTAIR group,poliferation and invasion of SGC7901 cells were significantly increased in si HOTAIR ＋ PGE2 group（P 0.05）. Conclusion：Downregulation of lnc RNA HOTAIR would inhibit cell viability,invasion and migration capability of gastric cancer cells,which were mediated partially by inhibiting the expression of COX-2 and then upregulating the expression of E-cadherin. HOTAIR might be a promising target to modulate the invasion and metastasis of gastric caner.