Bapx1在胃癌中参与转化生长因子-β诱发的上皮间质转化

发布时间：2018-06-26 14:23

本文选题：Bapx1 + 胃癌　；参考：《南方医科大学》2017年博士论文

【摘要】：背景:胃癌仍然是威胁人类健康的一大类疾病,并有着相当高的至死率。胃癌的高死亡率与其较易发生转移的特性相关。上皮间质转化(Epithelia-mesenchymal transition,EMT)是以非运动的、有极性的、细胞连接紧密的上皮细胞,转化成为具有侵袭性的、非极性的、细胞连接松散的间质细胞为特点,在肿瘤的转移中起重要作用。同源结构域家族在胚胎发育的调控过程中占据着绝对重要的顶层地位,越来越多的证据表明它们在多种肿瘤中表达异常,并使肿瘤获得各种转移、侵袭、增殖等特性。同源结构域蛋白Bapx1(又名NKX3.2)是胃十二指肠形态发生中的重要调节蛋白。但对于其在肿瘤中作用的研究甚少,最近有报道显示Bapx1在卵巢癌中的高表达与远处转移和化疗抵抗有关,对于其机制也并没有进行深入研究。目前尚没有关于其在胃癌中的研究报道。转化生长因子β(transforming growth factor-β,TGF-β)被认为是在发育过程、癌症以及其他病理状态下诱导EMT最重要的因子,已被证明能促进多种肿瘤细胞的转移。Bapx1在胚胎样的细胞中被证明做为TGF-β和BMP(bone morphogenetic proteins)的下游而进一步发挥作用。NF-κB是参与肿瘤细胞侵袭转移的重要信号通路,已有报道显示,NF-κB参与了 TGF-β介导的EMT。而在软骨细胞中的研究显示,Bapx1可激活NF-κB,促进NF-κB的入核。本研究的目的是探索Bapx1在胃癌中的作用及其可能的机制。方法:免疫组化和Western-Blot法来研究Bapx1在胃癌和其对应的癌旁组织以及胃癌细胞株与胃永生化上皮细胞株中的表达;在BGC823和MGC803细胞中瞬时转染沉默Bapx1后进一步观察其迁移侵袭功能并用Western-Blot来验证EMT相关蛋白的表达;在BGC823和MGC803细胞中加入TGF-β刺激,进一步探究Bapx1对TGF-β诱导的EMT的作用;其后进一步研究Bapx1对EMT影响的可能下游机制。统计学检验使用SPSS软件。T检验或ANOVA来比较差异的显著性。Spearman相关性分析Bapx1表达量与各临床指标间的相关性。应用Kaplan-Meier方法评估各临床指标及Bapx1免疫组化评分对胃癌患者预后的影响。结果:Bapx1的表达在胃癌组织中远高于其相邻的癌旁组织。Bapx1在胃癌细胞株中的表达高于胃永生化上皮细胞株的表达。且它的表达与TNM分期,淋巴和远处转移以及死亡率呈正相关。而在BGC823和MGC803胃癌细胞株中沉默Bapx1,可减弱胃癌细胞的侵袭和迁移能力,同时减少胃癌细胞间质表型,增加胃癌细胞上皮表型。TGF-β刺激可诱导BGC823和MGC803细胞株的EMT,同时Bapx1的表达增加,但当下调Bapx1的表达后,可以逆转TGF-β诱导的侵袭、迁移和形态学变化以及EMT的表型变化。进一步的研究显示,在胃癌细胞中沉默Bapx1可减少NF-κB的核定位表达,提示胃癌细胞中Bapx1的高表达至少部分地参与了 NF-κB的激活。结论:该研究提示,Bapx1在胃癌中的高表达与胃癌的淋巴、远处转移及不良预后有关,在体外实验中证实Bapx1可通过介导TGF-β诱导的EMT进而促进胃癌的侵袭和转移,并进一步推测Bapx1有可能通过激活NF-κB通路而参与介导TGF-β诱导的EMT。
[Abstract]:Background: gastric cancer is still a major disease that threatens human health and has a fairly high death rate. The high mortality rate of gastric cancer is related to the characteristics that are easier to metastasize. Epithelia-mesenchymal transition (EMT) is a non athletic, polar, cell connected epithelial cell that is transformed into an invasion. Sexual, nonpolar, loosely connected stromal cells, which play an important role in the metastasis of a tumor. The family of homologous domains occupies an absolutely important position in the regulation of embryonic development. More and more evidence shows that they are abnormal in a variety of tumors and make the tumor a variety of metastasis, invasion, and proliferation. Homologous domain protein Bapx1 (also known as NKX3.2) is an important regulatory protein in the formation of gastroduodenal morphogenesis. However, few studies have been made on its role in the tumor. Recently, it has been reported that the high expression of Bapx1 in ovarian cancer is related to distant metastasis and chemotherapy resistance, and the mechanism has not been deeply studied. Transforming growth factor- beta (TGF- beta) is considered to be the most important factor in the induction of EMT in development, cancer and other pathological conditions. It has been proved to be able to promote the transfer of.Bapx1 in a variety of tumor cells to be proved to be TGF- beta and BMP (bone m) in embryonic like cells. In the lower reaches of orphogenetic proteins,.NF- kappa B is an important signaling pathway involved in the invasion and metastasis of tumor cells. It has been reported that NF- kappa B participates in TGF- beta mediated EMT. in cartilage cells and shows that Bapx1 activates NF- kappa B and promotes the nucleation of NF- kappa. The purpose of this study is to explore the gastric cancer. Effects and possible mechanisms. Methods: immunohistochemical and Western-Blot methods were used to study the expression of Bapx1 in gastric carcinoma and its corresponding para cancer tissues, gastric cancer cell lines and gastric immortalized epithelial cells. After transient transfection of silent Bapx1 in BGC823 and MGC803 cells, the migration and invasion function was further observed and Western-Blot was used to verify EMT. The expression of related proteins; adding TGF- beta stimulation in BGC823 and MGC803 cells to further explore the effect of Bapx1 on EMT induced by TGF- beta; then further study the possible downstream mechanism of Bapx1 on EMT. Statistical tests use SPSS software.T test or ANOVA to compare the distinct.Spearman correlation analysis The correlation between clinical indicators. Kaplan-Meier method was used to evaluate the effect of various clinical indicators and Bapx1 immunohistochemical scores on the prognosis of gastric cancer patients. Results: the expression of Bapx1 in gastric carcinoma tissue is much higher than that of adjacent tissue,.Bapx1 expression in gastric cancer cell lines is higher than that of gastric immortalized epithelial cell lines. TNM staging, lymphoid and distant metastasis and mortality are positively correlated. While silencing of Bapx1 in BGC823 and MGC803 gastric cancer cell lines can weaken the invasion and migration of gastric cancer cells, reduce the phenotype of gastric cancer cells, and increase the.TGF- beta stimulation of the epithelial phenotype of gastric cancer cells to induce EMT in BGC823 and MGC803 cell lines and increase the expression of Bapx1. Addition, when the expression of Bapx1 was downregulated, it could reverse the invasion, migration and morphological changes of TGF- beta induced, and the phenotypic changes of EMT. Further studies showed that the silence of Bapx1 in gastric cancer cells could reduce the nuclear localization and expression of NF- kappa B, suggesting that the high expression of Bapx1 in gastric cancer cells was at least partly involved in the activation of NF- kappa B. Conclusion: the study It is suggested that the high expression of Bapx1 in gastric cancer is related to the lymph, distant metastasis and poor prognosis of gastric cancer. In vitro experiments have proved that Bapx1 can promote the invasion and metastasis of gastric cancer by mediating EMT induced by TGF- beta and further promoting the invasion and metastasis of gastric cancer, and further speculate that Bapx1 may be involved in the mediation of TGF- beta induced EMT. through the activation of the NF- kappa B pathway.
【学位授予单位】：南方医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R735.2

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