本文選題：胃癌　切入點(diǎn)：STAT3　出處：《中國人民解放軍醫(yī)學(xué)院》2017年碩士論文

【摘要】：背景:胃癌是全球發(fā)病率第四位,死亡率第二位的常見惡性腫瘤。我國每年有40多萬例新發(fā)病例,約占世界新發(fā)病例數(shù)42%,每年約35萬人死于胃癌,在我國城市地區(qū),該病是導(dǎo)致病人死亡的第二位原因。PI3K/AKT/mTOR信號(hào)通路在腫瘤細(xì)胞中被異常激活,因此一系列針對該信號(hào)通路分子的抑制劑被開發(fā)并進(jìn)入臨床實(shí)驗(yàn)。靶向治療藥物的出現(xiàn)大大促進(jìn)了胃癌治療的進(jìn)展,但是腫瘤細(xì)胞不可避免地產(chǎn)生耐藥性限制了針對該信號(hào)通路抑制劑的治療效果,且分子機(jī)制也不清楚。STAT3反饋激活在腫瘤細(xì)胞對廣泛的腫瘤靶向治療藥物產(chǎn)生耐藥性過程中發(fā)揮主導(dǎo)作用。因此研究針對這兩種靶點(diǎn)聯(lián)合用藥的策略,對于改善胃癌靶向性治療療效具有重要的意義。目的:分析和揭示STAT3激酶反饋激活是PTEN缺失的胃癌細(xì)胞對PI3K/AKT/mTOR抑制劑產(chǎn)生耐藥性的重要因素;闡明STAT3激酶反饋激活的分子機(jī)制;探索以STAT3激酶和PI3K/AKT/mTOR為胃癌治療靶點(diǎn),聯(lián)合用藥的策略以及對胃癌細(xì)胞的協(xié)同抑制功能。方法:利用 PI3K/AKT/mTOR 抑制劑(LY294002、BEZ235、MK2206、RAD001)單一或聯(lián)合STAT3激酶抑制劑(STATTIC)處理一系列胃癌細(xì)胞系,利用Western-blot檢測AKT激酶和STAT3激酶的表達(dá)及磷酸化水平;應(yīng)用流式細(xì)胞技術(shù)等觀察單一或聯(lián)合用藥后對細(xì)胞周期、凋亡等細(xì)胞現(xiàn)象的影響;通過siRNA建立了 HGC27敲低STAT3表達(dá)的穩(wěn)定細(xì)胞系,并建立相應(yīng)的荷瘤小鼠模型,然后通過CCK8實(shí)驗(yàn)、平板克隆實(shí)驗(yàn)等檢測細(xì)胞生長;利用荷瘤小鼠模型,檢測STAT3表達(dá)前后以及BEZ235處理后胃癌細(xì)胞生長速度。結(jié)果:(1)在PTEN陰性的胃癌細(xì)胞中,PI3K/AKT/mTOR信號(hào)通路抑制劑反饋激活STAT3激酶活性;(2)抑制STAT3激酶活性能夠增加胃癌細(xì)胞對PI3K/AKT/mTOR抑制劑的敏感性;(3)抑制PI3K/AKT/mTOR激酶和STAT3激酶活性協(xié)同抑制胃癌細(xì)胞生長;(4) SDF-1/CXCR4軸參與了 STAT3反饋激活,STAT3的反饋激活與細(xì)胞分泌的可溶性細(xì)胞因子以及遺傳背景等有關(guān)。結(jié)論:在PTEN陰性的胃癌細(xì)胞中,P13K/AKT/mTOR抑制劑反饋激活STAT3激酶活性,并與某些可溶性細(xì)胞因子有關(guān),這對于理解腫瘤耐藥性提供了一定的基礎(chǔ)。聯(lián)合抑制STAT3激酶和PI3K/AKT/mTOR激酶活性協(xié)同抑制胃癌細(xì)胞生長。該研究結(jié)果為PTEN陰性胃癌患者的治療策略提供了指導(dǎo)。
[Abstract]:Background: gastric cancer is the fourth most common malignant tumor in the world. There are more than 400,000 new cases every year in China, accounting for 42 million new cases in the world. About 350000 people die of gastric cancer every year. The disease is the second leading cause of death. The PI3K / AKT / mTOR signaling pathway is unusually activated in tumor cells. Therefore, a series of inhibitors targeting the signaling pathway molecules have been developed and entered clinical trials. The emergence of targeted therapeutic drugs has greatly promoted the progress of gastric cancer treatment. But the inevitable drug resistance of tumor cells limits the therapeutic effect of the signaling pathway inhibitor. And the molecular mechanism is not clear. STAT3 feedback activation plays a leading role in the development of drug resistance of tumor cells to a wide range of tumor targeted treatment drugs. Objective: to analyze and reveal that the activation of STAT3 kinase feedback is an important factor in the drug resistance of gastric cancer cells with PTEN deficiency to PI3K/AKT/mTOR inhibitors, and to elucidate the molecular mechanism of STAT3 kinase feedback activation. Methods: a series of gastric cancer cell lines were treated by PI3K/AKT/mTOR inhibitor LY294002BEZ235MK2206 RAD001 (single or combined with STAT3 kinase inhibitor STATTIC). Western-blot was used to detect the expression and phosphorylation of AKT kinase and STAT3 kinase, and flow cytometry was used to observe the effect of single or combined administration on cell cycle and apoptosis. A stable cell line with low STAT3 expression of HGC27 knockout was established by siRNA, and the corresponding tumor-bearing mouse model was established. Then, the cell growth was detected by CCK8 experiment, plate cloning assay and so on, and the tumor-bearing mouse model was used. The growth rate of gastric cancer cells was measured before and after STAT3 expression and after BEZ235 treatment. Results the inhibition of STAT3 kinase activity by PI3K / AKT / mTOR signaling pathway inhibitor feedback activated STAT3 kinase activity in PTEN negative gastric cancer cells could increase the activity of STAT3 kinase in gastric cancer cells with PI3K/AKT/mTOR. The inhibitory activity of PI3K/AKT/mTOR kinase and STAT3 kinase combined with inhibition of growth of gastric cancer cells by SDF-1/CXCR4 axis is involved in the feedback activation of STAT3 feedback activator STAT3, which is related to soluble cytokines secreted by the cells and genetic background. Conclusion: P13K / AKT / mTOR inhibitor feedback activates the activity of STAT3 kinase in PTEN negative gastric cancer cells. And related to some soluble cytokines, This study provides a basis for understanding tumor resistance. The combination of inhibition of STAT3 kinase and PI3K/AKT/mTOR kinase activity in combination with the inhibition of gastric cancer cell growth. The results of this study provide guidance for the treatment strategy of PTEN negative gastric cancer patients.
【學(xué)位授予單位】：中國人民解放軍醫(yī)學(xué)院
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：R735.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 黃林飛;陸航;宮喜明;付曉光;;CXCR4-shRNA對人胃癌細(xì)胞SGC7901裸鼠腹腔轉(zhuǎn)移瘤生長轉(zhuǎn)移影響的實(shí)驗(yàn)研究[J];北京醫(yī)學(xué);2013年05期

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本文編號(hào)：1672926