寇衛(wèi)政,孫為豪
(1.新鄉(xiāng)醫(yī)學(xué)院第一附屬醫(yī)院腫瘤科,河南新鄉(xiāng)453100;2.南京醫(yī)科大學(xué),江蘇南京210029)
胃泌素/CCK2R通過JAK 2/STAT3通路促進(jìn)胃癌侵襲力轉(zhuǎn)移的分子機(jī)制研究
寇衛(wèi)政1,孫為豪2
(1.新鄉(xiāng)醫(yī)學(xué)院第一附屬醫(yī)院腫瘤科,河南新鄉(xiāng)453100;2.南京醫(yī)科大學(xué),江蘇南京210029)
目的探討胃泌素/CCK2R通過JAK2/STAT3通路促進(jìn)胃癌侵襲力轉(zhuǎn)移的分子機(jī)制。方法胃泌素和AG490(tyrphostin AG490)干預(yù)MKN45胃癌細(xì)胞24h,胃癌細(xì)胞傷愈實(shí)驗(yàn)和Transwell小室實(shí)驗(yàn)檢測(cè)胃泌素對(duì)胃癌細(xì)胞體外遷移和侵襲的影響,Western blot檢測(cè)胃癌細(xì)胞中基質(zhì)金屬蛋白酶2(matrixmetalloprotei-ase-2,MMP-2)、轉(zhuǎn)錄激活因子3(singnal transducers and activators of transcription3,STST3)和磷酸化信號(hào)轉(zhuǎn)導(dǎo)與轉(zhuǎn)錄激活因子3(phosphorylated-singnal transducers and activators of transcription3,P-STAT3)蛋白水平。結(jié)果胃泌素組胃癌細(xì)胞遷入細(xì)胞致傷區(qū)的相對(duì)距離和遷移侵襲到Transwell小室下部的細(xì)胞數(shù)分別顯著高于和多于空白對(duì)照組(P<0.05);AG490組分別顯著低于和少于空白對(duì)照組(P<0.05);AG490+胃泌素組分別顯著高于和多于AG490組(P<0.05);胃泌素組胃癌細(xì)胞中MMP-2和P-STAT3蛋白水平顯著高于空白對(duì)照組(P<0.05);AG490組顯著低于空白對(duì)照組(P<0.05);AG490+胃泌素組顯著高于AG490組(P<0.05)。結(jié)論胃泌素可以促進(jìn)胃癌細(xì)胞體外遷移和侵襲,并且胃泌素促進(jìn)胃癌細(xì)胞體外遷移和侵襲的可能機(jī)制是通過激活JAK2/STAT3信號(hào)轉(zhuǎn)導(dǎo)通路,使MMP-2蛋白和合成量增加,細(xì)胞外基質(zhì)降解,導(dǎo)致胃癌細(xì)胞體外遷移和侵襲過程中所受阻力減少。
胃泌素;侵襲;遷移;分子機(jī)制;胃癌
胃癌是目前嚴(yán)重威脅人類生命健康的一種惡性腫瘤,且病 死率較高,有研究統(tǒng)計(jì)表明胃癌是導(dǎo)致患者死亡的第二大惡性腫瘤[1]。目前對(duì)胃癌的發(fā)病機(jī)制研究較多,但還未找到確切的發(fā)病機(jī)制。近年來研究表明胃癌的發(fā)生與胃癌患者體內(nèi)胃泌素的異常升高有著密切關(guān)系[2]。胃泌素是由胃竇部位的G細(xì)胞合成分泌的,在正常的環(huán)境下胃泌素促進(jìn)機(jī)體胃酸的分泌,但已有臨床研究表明胃泌素的的異常過多表達(dá)往往與惡性腫瘤的發(fā)生存在十分緊密的關(guān)系[3],已有體外實(shí)驗(yàn)證明胃泌素可以促進(jìn)多種癌細(xì)胞的增殖,侵襲和轉(zhuǎn)移,如肝癌細(xì)胞、胃腸道癌細(xì)胞、胰腺癌細(xì)胞等等[4-6]。已有研究表明JAK2/STAT3信號(hào)轉(zhuǎn)導(dǎo)通路參與多種腫瘤細(xì)胞的侵襲和轉(zhuǎn)移,在惡性腫瘤的發(fā)生與發(fā)展過程中起著重要的作用[7]。本文通過胃泌素干擾MKN45胃癌細(xì)胞系,觀察相應(yīng)的指標(biāo),探討胃泌素是否通過JAK2/STAT3信號(hào)轉(zhuǎn)導(dǎo)通路促進(jìn)胃癌細(xì)胞侵襲轉(zhuǎn)移,為胃癌的治療尋找新的治療途徑以及相關(guān)的理論依據(jù)。
1.1 材料 MKN45胃癌細(xì)胞系購(gòu)買自上海研謹(jǐn)生物科技有限公司,五肽胃泌素購(gòu)自(上海麗珠東風(fēng)生物技術(shù)公司,批號(hào)20140202),AG490購(gòu)自(SIGMA公司,批號(hào)S27831),Matrigel基質(zhì)膠購(gòu)自(BD公司);Transwell小室購(gòu)自(Corning)公司;RIPA裂解緩沖液購(gòu)自(碧云天生物技術(shù)研究所);P-STAT3、STAT3、MMP-2抗體購(gòu)自(Bioworlde公司,批號(hào):360703、361001、351034)。垂直電泳槽、Hofer電泳儀購(gòu)自(Amersham Biosciences公司)。
1.2 方法
1.2.1 細(xì)胞培養(yǎng)及分組:將所購(gòu)買的MKN45胃癌細(xì)胞在DMEM培養(yǎng)液中培養(yǎng),培養(yǎng)的條件為:培養(yǎng)液中加入10%小牛血清,37℃,5%CO2濃度,恒溫箱培養(yǎng),每隔1天更換1次培養(yǎng)液,每培養(yǎng)3天進(jìn)行細(xì)胞傳代1次。用培養(yǎng)細(xì)胞的培養(yǎng)液將胃泌素稀釋為45μg/m L,AG490稀釋為50μg/mL。取細(xì)胞生長(zhǎng)處于對(duì)數(shù)期的MKN45胃癌細(xì)胞,將胃癌細(xì)胞分為4組:空白對(duì)照組,胃泌素組,AG490組,AG490+胃泌素組。將胃泌素和AG490分別加入到相應(yīng)組別的細(xì)胞中,干預(yù)24 h后進(jìn)行相應(yīng)指標(biāo)的檢測(cè)。
1.2.2 MKN45胃癌細(xì)胞傷愈實(shí)驗(yàn):將生長(zhǎng)處于對(duì)數(shù)期的MKN45細(xì)胞接種于12孔培養(yǎng)板中,每孔接種的細(xì)胞數(shù)為4×105個(gè),將接種后的12孔板放入培養(yǎng)箱中培養(yǎng)過夜,培養(yǎng)條件為37℃,5%CO2濃度。過夜后細(xì)胞鋪滿12孔板底部,用移液槍頭在12孔板底部相同位置畫一條寬度相同的胃癌細(xì)胞刮出帶,然后在空白對(duì)照組加入5mL的含有10%小牛血清的DMEM培養(yǎng)液,在胃泌素組加入2.5 mL的胃泌素稀釋液和2.5 mL的含10%小牛血清的DMEM培養(yǎng)液,在AG490組加入2.5 mL的AG490稀釋液和2.5mL的含10%小牛血清的DMEM培養(yǎng)液,在AG490+胃泌素組加2.5mL的AG490稀釋液和胃泌素稀釋液。將所有孔加入相應(yīng)的溶液后在培養(yǎng)箱中培養(yǎng)24 h,24 h后在倒置顯微鏡下觀察并測(cè)量癌細(xì)胞向刮出帶遷移的相對(duì)距離,即培養(yǎng)箱0 h的細(xì)胞刮出帶的寬度與培養(yǎng)24 h的細(xì)胞刮出帶的寬度,本實(shí)驗(yàn)重復(fù)3次。
1.2.3 MKN45胃癌細(xì)胞Transwell小室實(shí)驗(yàn):將Matrigel基質(zhì)膠與不含小牛血清的DMEM培養(yǎng)基預(yù)冷,將不含小牛血清的DMEM培養(yǎng)基與溶解為液態(tài)的Matrigel基質(zhì)膠按照1∶5的體積比混溶,在每孔Transwell小室的上部加入上述混合溶液40μL,在37℃的恒溫相中放置5小時(shí),待其凝固,再在凝固的Transwell小室的上部加入70μL的不含小牛血清的DMEM培養(yǎng)基,并在每孔Transwell小室的上部培養(yǎng)基中接種5×104個(gè)處于生長(zhǎng)對(duì)數(shù)期的MKN45胃癌細(xì)胞,在Transwell小室的下部加入含有30%小牛血清的DMEM培養(yǎng)基500μL。將Transwell小室放置在培養(yǎng)箱中培養(yǎng)24 h,培養(yǎng)箱的條件為:37℃、5%CO2濃度。培養(yǎng)24 h后棄去Transwell小室上部沒有傳入基質(zhì)膠中的胃癌細(xì)胞,10%甲醛固定,時(shí)間為20min,吉姆薩紫染色,時(shí)間為15min。在倒置顯微鏡下觀察并拍照,計(jì)數(shù)胃癌細(xì)胞侵襲轉(zhuǎn)移到Transwell小室下部的個(gè)數(shù),本實(shí)驗(yàn)重復(fù)3次。
1.2.4 Western blot檢測(cè)MKN45胃癌細(xì)胞中MMP-2、STAT3和P-STAT3的表達(dá):取生長(zhǎng)處于對(duì)數(shù)期的MKN45胃癌細(xì)胞接種到培養(yǎng)瓶中,胃泌素和AG490分別加入到相應(yīng)的組別的培養(yǎng)瓶中,將加入好相應(yīng)試劑的培養(yǎng)瓶放入到培養(yǎng)箱中進(jìn)行培養(yǎng),培養(yǎng)的條件為:37℃、5%CO2濃度,培養(yǎng)干預(yù)24 h。收集各組培養(yǎng)干預(yù)24 h的胃癌細(xì)胞,RIPA細(xì)胞裂解液裂解胃癌細(xì)胞,提取胃癌細(xì)胞中的總蛋白,總蛋白提取液與上樣緩沖液混合沸煮,在聚丙烯酰胺凝膠中電泳分離蛋白,在轉(zhuǎn)移緩沖液中將蛋白轉(zhuǎn)移至NC膜中,5%脫脂奶粉封閉1 h,PBSX洗膜3次,每次10 min,Akt、MMP-2、STAT3和P-STAT3一抗4℃孵育過夜,PBSX洗膜3次,每次10min,二抗常溫孵育2 h,PBSX洗膜3次,每次10 min,在暗室中在目的蛋白的相應(yīng)位置涂ECL發(fā)光試劑,待發(fā)光時(shí)用膠片曝光,掃描曝光后的膠片,分析各目的蛋白的積分光密度值,并進(jìn)行統(tǒng)計(jì)分析,每組蛋白重復(fù)3次。
1.3 統(tǒng)計(jì)學(xué)方法 采用SPSS17.0統(tǒng)計(jì)學(xué)軟件進(jìn)行實(shí)驗(yàn)數(shù)據(jù)分析,正態(tài)計(jì)量數(shù)據(jù)用“±s”表示,正態(tài)資料組間比較采用t檢驗(yàn);以P<0.05為差異有統(tǒng)計(jì)學(xué)意義。
2.1 MKN45胃癌細(xì)胞傷愈實(shí)驗(yàn) 鋪滿胃癌細(xì)胞的12孔板底部畫出細(xì)胞刮出帶,用胃泌素和AG490干預(yù)24 h后,觀察結(jié)果表明空白對(duì)照組、胃泌素組、AG490組和AG490+胃泌素組的細(xì)胞刮出帶的寬度均有減小,都有胃癌細(xì)胞向致傷區(qū)遷移。胃泌素組細(xì)胞刮出帶的寬度顯著小于空白對(duì)照組(P<0.05);AG490組細(xì)胞刮出帶的寬度顯著大于空白對(duì)照組(P<0.05);AG490加胃泌素組細(xì)胞刮出帶的寬度顯著小于AG490組,(P<0.05)。結(jié)果提示胃泌素促進(jìn)胃癌細(xì)胞的遷移,JAK2激酶抑制劑AG490抑制胃癌細(xì)胞的遷移(見表1、圖1)。
表1 胃泌素與AG490對(duì)MKN45胃癌細(xì)胞傷愈實(shí)驗(yàn)的影響Tab.1 The impact of gastrin and AG490 on MKN45 gastric cancer cell injury experiments
圖1 胃泌素與AG490對(duì)MKN45胃癌細(xì)胞傷愈實(shí)驗(yàn)的影響(LM×200)Fig.1 The impact of gastrin and AG490 on MKN45 gastric cancer cell injury experiments(LM×200)
2.2 MKN45胃癌細(xì)胞Transwell小室實(shí)驗(yàn) 在Transwell小室的上部接種處于生長(zhǎng)對(duì)數(shù)期的胃癌細(xì)胞,在經(jīng)過胃泌素和AG490干預(yù)24 h后,觀察結(jié)果表明在空白對(duì)照組、胃泌素組、AG490組和AG490+胃泌素組均有胃癌細(xì)胞侵襲到Transwell小室的下部。胃泌素組侵襲到Transwell小室下部的細(xì)胞數(shù)顯著多于空白對(duì)照組(P<0.05);AG490組侵襲到Transwell小室下部的細(xì)胞數(shù)顯著少于空白對(duì)照組(P<0.05);AG490+胃泌素組侵襲到Transwell小室下部的細(xì)胞數(shù)顯著多于AG490組(P<0.05,見表2,圖2)。
表2 胃泌素與AG490對(duì)MKN45胃癌細(xì)胞Transwell小室實(shí)驗(yàn)的影響Tab.2 Impact of gastrin and AG490 on gastric cancer cell Transwell chamber experiments
圖2 胃泌素與AG490對(duì)MKN45胃癌細(xì)胞Transwell小室實(shí)驗(yàn)的影響(吉姆薩染色×200)Fig.2 The impact of gastrin and AG490 for Transwell chamber experiments on MkN45 gastric cancer cell
2.3 MKN45胃癌細(xì)胞中MMP-2表達(dá)水平的變化 生長(zhǎng)處于對(duì)數(shù)期的MKN45胃癌細(xì)胞經(jīng)過胃泌素和AG490干預(yù)24 h后,采用Western blot法檢測(cè)胃癌細(xì)胞中MMP-2表達(dá)水平。檢測(cè)結(jié)果表明胃泌素組MMP-2表達(dá)水平顯著高于空白對(duì)照組(P<0.05);AG490組MMP-2表達(dá)水平顯著低于空白對(duì)照組(P<0.05);AG490+胃泌素組MMP-2的表達(dá)水平顯著高于AG490組(P<0.05,見圖3)。
圖3 MKN45胃癌細(xì)胞中MMP-2水平變化1.胃泌素組;2.AG490組;3.AG490+胃泌素組;4.空白對(duì)照組△P<0.05空白對(duì)照組比較;#P<0.05與AG490組比較,F(xiàn)ig.3 MMP-2 levels in MKN45 gastric cancer cells1.Gastrin group;2.AG490 group;3.AG490 and gastrin group;4.Control group;compared with control group Each group△P<0.05;#P<0.05 compared with AG490 group
2.4 MKN45胃癌細(xì)胞中STAT3和P-STAT3表達(dá)水平的變化 生長(zhǎng)處于對(duì)數(shù)期的MKN45胃癌細(xì)胞經(jīng)過胃泌素和AG490干預(yù)24 h后,采用Western blot法檢測(cè)胃癌細(xì)胞中MMP-2表達(dá)水平。檢測(cè)結(jié)果表明STAT3的表達(dá)水平在各組胃癌細(xì)胞中沒有顯著變化;胃泌素組P-STAT3的表達(dá)水平顯著高于空白對(duì)照組(P<0.05);AG490組P-STAT3的表達(dá)水平顯著低于空白對(duì)照組(P<0.05);AG490加胃泌素組P-STAT3的表達(dá)水平顯著高于AG490組(P<0.05,見圖4)。
圖4 MKN45胃癌細(xì)胞中STAT3和P-STAT3水平變化1.胃泌素組;2.AG490組;3.AG490+胃泌素組;4.空白對(duì)照組#P<0.05,與空白對(duì)照組比較;△P<0.05,AG490加胃泌素組與AG490組比較Fig.4 STAT3 and P-STAT3 levels in MKN45 gastric cancer cells1.Gastrin group;2.AG490 group;3.AG490 and gastrin group;4.control group;#P<0.05,compared with control group;△P<0.05,AG490 and gastrin group compared with AG490 group
胃癌的轉(zhuǎn)移是一個(gè)相當(dāng)復(fù)雜的生物過程,而胃癌細(xì)胞的遷移是該過程的起始階段。細(xì)胞外基質(zhì)是阻止胃癌細(xì)胞遷移的重要的分子骨架,細(xì)胞外基質(zhì)使胃癌細(xì)胞粘附,但體內(nèi)環(huán)境中存在著一些相關(guān)因子可以破壞細(xì)胞外基質(zhì),使細(xì)胞外基質(zhì)降解,使得胃癌細(xì)胞的遷移所受到阻力減小。這些相關(guān)因子表達(dá)水平的異常增多往往導(dǎo)致胃癌細(xì)胞的遷移。而胃癌細(xì)胞的轉(zhuǎn)移不但影響著惡性腫瘤的臨床治療效果,也會(huì)嚴(yán)重的影響惡性腫瘤患者的預(yù),可導(dǎo)致病情的不可控甚至死亡[8]。已有研究表明胃癌的發(fā)生發(fā)展與胃腸道內(nèi)的多種激素的異常有關(guān),Takaishi等[9]研究證實(shí)胃泌素表達(dá)的異常與胃癌的發(fā)生發(fā)展存在極為緊密的關(guān)系,是促進(jìn)胃癌病情加重的細(xì)胞因子。胃泌素的異常合成與分泌往往與胃癌的發(fā)生有著極為密切的關(guān)系[10-11]。
實(shí)驗(yàn)研究表明胃泌素對(duì)MKN45胃癌細(xì)胞中MMP-2表達(dá)水平的變化,STAT3和P-STAT3表達(dá)水平均有統(tǒng)計(jì)學(xué)意義(P<0.05)。胃泌素促進(jìn)胃癌細(xì)胞的體外遷移和侵襲可能是由于胃泌素促進(jìn)MMP-2表達(dá)水平的提高,降解細(xì)胞外基質(zhì),使胃癌細(xì)胞遷移和侵襲過程中所遇阻力降低;AG490是JAK2活化的特異性抑制劑,可以特異性的抑制JAK2的活化,進(jìn)而使得STAT3磷酸為P-STAT3的程度降低,最終使得DNA中表達(dá)VEGF、MMP-2的基因表達(dá)減少,體內(nèi)MMP-2的水平減少,細(xì)胞外基質(zhì)的降解程度降低,癌細(xì)胞發(fā)生遷移和侵襲的能力降低[12]。
綜上所述胃泌素可以促進(jìn)胃癌細(xì)胞體外遷移和侵襲,并且胃泌素促進(jìn)胃癌細(xì)胞體外遷移和侵襲的可能機(jī)制是通過胃泌素與細(xì)胞膜上的受體結(jié)合,然后再通過活化JAK2/STAT3信號(hào)轉(zhuǎn)導(dǎo)通路使得MMP-2蛋白和合成量增加,使得細(xì)胞外基質(zhì)降解,導(dǎo)致胃癌細(xì)胞體外遷移和侵襲過程中所受阻力減少。
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(編校:譚玲,王冬梅)
Study on molecular mechanism of gastrin/CCK2R by JAK2/STAT3 pathway promotesmetastasis of gastric cancer invasion force
KOUWei-zheng1,SUNWei-Hao2
(1.Department of Oncology,F(xiàn)irst Affiliated Hospital of Xinxiang Medical College,Xinxiang 453100,China;2.Nanjing Medical University,Nanjing 210029,China)
ObjectiveTo investigate the gastrin/CCK2R by JAK2/STAT3 pathway promotes invasiveness of themolecularmechanism of gastric cancermetastasis.MethodsGastrin and AG490(Tyrphostin AG490)interfered MKN45 gastric cancer cells 24 hours,cells were recovered from the impact of gastric Transwell chamber experiments and in vitro assay of gastrin gastric cancer cellmigration and invasion,protein levels of gastric cancer cells in Matrixmetallo protei-ase-2(MMP-2),singnal transducers and activators of transcription3(STST3)and phosphorylated-Singnal transducers and activators of transcription3(P-STAT3)were detected by Western blot.ResultsGastrin group moved into cells of gastric cancer cellmigration and invasion to the relative distance and the lower Transwell chamber to cell injury were significantly higher than andmore than the controlgroup(P<0.05);AG490 group were significantly lower than and less than the control group(P<0.05);AG490 plus gastrin group were significantly higher than and more than AG490 group(P<0.05);gastrin group gastric cancer cellMMP-2 and P-STAT3 protein levelswere significantly higher than the controlgroup(P<0.05);AG490 group was significantly lower than the control group(P<0.05);AG490 plus gastrin group was significantly higher than AG490 group(P<0.05).ConclusionGastrin can promote gastric cancer cellmigration and invasion in vitro,and gastrin promote gastric cancer cell invasion in vitro migration and possible mechanism is through the activation of JAK2/STAT3 signal transduction pathways,so that MMP-2 protein and synthesis increase,extracellularmatrix degradation,leading to reduce gastric cancer cellmigration and invasion in vitro process suffered resistance.
gastrin;invasion;migration;molecularmechanisms;gastric
R735.2
A
1005-1678(2014)09-0038-04
國(guó)家自然科學(xué)基金(81072030)
寇衛(wèi)政,男,碩士研究生,主治醫(yī)師,研究方向:消化道惡性腫瘤綜合治療,E-mail:qch1821460033@163.com。