【作者】 李杰；

【导师】 叶延伟；

【作者基本信息】 郑州大学 ， 外科学（普外）， 2019， 硕士

【摘要】 背景与目的:目前胃癌靶向治疗的相关研究成为一大热点。曲妥珠单抗、赫赛汀治疗晚期胃癌的效果并不令人满意。因此,新的分子靶点是否在胃癌的发生和发展中起重要作用,是否有进一步的靶向药物值得研究和开发,将成为胃癌研究领域的新的突破。近年来,成纤维细胞生长因子受体(Fibroblast growth factor receptor,FGFR)家族分子的相关研究越来越多,FGFR家族可能会为恶性肿瘤诊治提供新的突破。成纤维细胞生长因子受体4(Fibroblast growth factor receptor4,FGFR4)在恶性肿瘤增殖、侵袭和转移中起关键作用。目前FGFR4Gly388Arg多态性与恶性肿瘤之间的关系仍然存在争议,本课题为了阐明FGFR4-Arg388突变在胃癌中的作用,并探索这一单核苷酸多态性(single nucleotide polymorphism,SNP)作为潜在治疗靶点可能性。第一部分:FGFR4-Arg388突变通过激活STAT3途径诱导上皮间质细胞转化促进胃癌进展并减弱奥沙利铂的化疗效果目的:本研究为了阐明FGFR4-Arg388突变在胃癌中的作用,更重要的是探索该SNP作为潜在治疗靶点的可能性。方法:对晚期胃癌患者进行FGFR4基因型分组,进行统计学分析。构建不同FGFR4基因型的过表达胃癌细胞系,评估不同FGFR4基因型的细胞增殖、侵袭、迁移及对奥沙利铂的抗性,并探索其依赖的信号途径。结果:在102名GC患者中,FGFR4-Arg388患者的肿瘤分期较高(P=0.047),总生存期(OS)较差(P=0.033)。免疫组织化学结果显示,与FGFR4-Gly388患者相比,FGFR4-Arg388患者具有更高的Vimentin(P=0.025)和p-STAT3(P=0.009)表达。胃癌细胞中,与过表达Gly388等位基因的细胞相比,过表达的FGFR4 Arg388突变能够增加胃癌细胞的增殖、侵袭和浸润能力,能够弱化奥沙利铂的化疗效果。探索其机制发现可能是通过FGFR4-Arg388/信号传导子及转录激活子3(signal transducer and activator of transcription 3,STAT3)/上皮至间充质转化(epithelial-mesenchymal transition,EMT)轴调节胃癌细胞的致癌性质。结论:FGFR4-Arg388突变可能是胃癌辅助治疗的生物标志物和候选靶标。第二部分:FGFR4表达的沉默通过上皮-间质转化和STAT3信号通路影响胃癌的进展目的:探索FGFR4是否影响胃癌细胞的功能性,研究FGFR4与EMT、STAT3信号通路之间的关系。方法:利用sh RNA沉默胃癌细胞中FGFR4的表达,在FGFR4-sh RNA胃癌细胞系中探究细胞增殖、侵袭和迁移所依赖的FGFR4信号途径。结果:FGFR4-sh RNA组细胞的增殖、侵袭和迁移能力相比于mock组细胞和NC组细胞明显减弱。Westtern blot结果显示FGFR4-sh RNA组中,STAT3、p-STAT3及Vimentin表达明显降低,而E-cadherin有升高趋势。结论:沉默FGFR4表达影响胃癌的进程,这可能因为FGFR4与胃癌的EMT通路及STAT3通路之间存在相关性,FGFR4可能会成为治疗胃癌的潜在生物学靶点。全文结论:沉默FGFR4的表达,或者构建FGFR4过表达株,都能够影响胃癌的生物学特征,两种模型均证明FGFR4本身存在致癌性,值得强调的是,FGFR4Arg388突变型比FGFR4 Gly388型的致癌作用更强,更能够加速胃癌的进程,并且能够弱化奥沙利铂的化疗效果,与胃癌患者的不良预后相关,FGFR4及其Gly388Arg基因多态性在胃癌靶向治疗中值得深入探究。更多还原

【Abstract】 Background and Objective: At present,the research on targeted therapy of gastric cancer has become a hot topic.Trastuzumab and Herceptin are treated with advanced gastric cancer,but the overall effect was not satisfactory.Therefore,whether new molecular targets play an important role in the occurrence and development of gastric cancer,whether there are further targeted drugs worthy of research and development will become a further breakthrough in the field of gastric cancer research.In recent years,there have been more and more researches on FGFR(Fibroblast growth factor receptor)family molecules.Some scholars believe that the FGFR family is an emerging field in the diagnosis and treatment of malignant tumors,and has broad application prospects.Fibroblast growth factor receptor 4(FGFR4)plays a critical role in cancer progression involving in tumor proliferation,invasion,and metastasis.This study elucidated the role of FGFR4-Arg388 variant in gastric cancer,and more importantly highlighted the possibility of this single nucleotide polymorphism(SNP)as potential therapeutic targets.The First Part: FGFR4-Arg388 Variant Promotes Gastric Cancer Progression And Increases Resistance to Oxaliplatin by Activating STAT3 Pathway to Induce Epithelial-to-Mesenchymal TransitionObjective: This study elucidated the role of FGFR4-Arg388 variant in gastric cancer(GC),and more importantly highlighted the possibility of this single nucleotide polymorphism(SNP)as potential therapeutic targets.Methods: FGFR4 polymorphism was characterized in advanced GC patients to perform statistical analysis.FGFR4-dependent signal pathways involving cell proliferation,invasion,migration and resistance to oxaliplatin(OXA)in accordance with genotypes were also assessed in transfected GC cell lines.Results: Among 102 GC patients,the FGFR4-Arg388 patients showed significantly higher tumor stage(P=0.047)and worse overall survival(OS)(P=0.033)than the Gly388 patients.Immunohistochemical results showed that FGFR4-Arg388 patients were more likely to have higher vimentin(P=0.025)and p-STAT3(P=0.009)expression compared with FGFR4-Gly388 patients.In transfected GC cells,the over-expression of FGFR4-Arg388 variant increased proliferation,invasion and infiltration of GC cells,increasing resistance of GC cells to OXA compared with cells over-expressing the Gly388 allele.The exploration mechanism may be through FGFR4-Arg388/STAT3(signal transducer and activator of transcription 3)/epithelial to mesenchymal transition(EMT)axis regulating pivotal oncogenic properties of GC cells.Conclusion: The FGFR4-Arg388 variant may be a biomarker and a candidate target for adjuvant treatment of GC.The Second Part: Silencing of FGFR4 Affects the Progression of Gastric Cancer by Mediating Epithelial-to-Mesenchymal Transition and STAT3 Pathways Objective: To investigate whether FGFR4 affects the function of gastric cancer cells and explore the association of FGFR4 with EMT and STAT3 signaling pathway.Methods: Sh RNA was used to silence FGFR4 expression in gastric cancer cells.FGFR4-dependent signal pathways involving cell proliferation,invasion and migration were also assessed in FGFR4-sh RNA gastric cancer cell lines.Results: Compared with mock and NC cells,the proliferation,invasion and migration of FGFR4-sh RNA cells was considerably decreased.Westtern bolt showed that the expression of STAT3,p-STAT3 and Vimentin were significantly decreased in the FGFR4-sh RNA group,while E-cadherin was elevated.Conclusion: Silencing FGFR4 expression affects the progression of gastric cancer,which may be due to the correlation between FGFR4 and EMT pathway and STAT3 pathway of gastric cancer.FGFR4 may become a potential biological target for the treatment of gastric cancer.Full text conclusion: Conclusion: Silencing FGFR4 expression or constructing FGFR4 over-expression cell lines could affect the biological characteristics of gastric cancer.Both models demonstrated the carcinogenicity of FGFR4 itself.It was worth emphasizing that FGFR4 Arg388 variation was more carcinogenic than Gly388 allele,which it can accelerate the progress of gastric cancer,weaken the chemotherapy effect of oxaliplatin,and be related to the poor prognosis of gastric cancer patients.FGFR4 and its Gly388 Arg polymorphism are worthy of further investigation in the targeted therapy of gastric cancer.更多还原