王富民,張寰,許芳秀,曲金力,孔金玉,錢碧云,3,4
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非吸煙女性肺腺癌組織中miRNAs的表達(dá)與表皮生長(zhǎng)因子受體關(guān)系的研究
王富民1,2,張寰1,許芳秀1,曲金力1,孔金玉1,錢碧云1,3,4
摘要:目的探討非吸煙女性肺腺癌(ADC)組織中miR-155、miR-16、miR-25及miR-133a的表達(dá)與表皮生長(zhǎng)因子受體(EGFR)的關(guān)系及其臨床意義。方法112例非吸煙女性ADC患者按EGFR類型分為EGFR野生型組(n= 51)和EGFR突變型組(n=61)。用實(shí)時(shí)熒光定量PCR定量檢測(cè)2組ADC組織中4種miRNAs的表達(dá)量,比較2組4種miRNAs表達(dá)水平的差異。4種miRNAs表達(dá)量以平均數(shù)分層為高表達(dá)組和低表達(dá)組,比較2亞組患者間的生存差異。按年齡( 60歲,>60歲)、EGFR類型和miRNAs的表達(dá)量分層,進(jìn)行Kaplan-Meier生存分析和Cox比例風(fēng)險(xiǎn)回歸模型檢驗(yàn)。結(jié)果EGFR突變型組miR-25的表達(dá)水平高于EGFR野生型組(P<0.05)。不同年齡分層、不同EGFR類型組、miR-155、miR-16及miR-133a表達(dá)量患者的生存率差異無(wú)統(tǒng)計(jì)學(xué)意義,miR-25低表達(dá)者的生存率較高表達(dá)者更高(P<0.05)。在EGFR突變型組中4種miRNAs的表達(dá)量與ADC預(yù)后無(wú)關(guān)(P>0.05);在EGFR野生型組中miR-16、miR-25、miR-133a低表達(dá)者較高表達(dá)者生存率更高(P<0.05)。Cox比例風(fēng)險(xiǎn)回歸分析顯示,miR-25高表達(dá)是非吸煙女性ADC患者預(yù)后死亡的獨(dú)立危險(xiǎn)因素(P<0.05)。結(jié)論miR-25是非吸煙女性ADC的獨(dú)立預(yù)后指標(biāo)。miR-25在非吸煙女性ADC,特別是在EGFR野生型的患者中表達(dá)升高,可能提示患者預(yù)后不佳。
關(guān)鍵詞:受體,表皮生長(zhǎng)因子;吸煙;性別因素;基因表達(dá);肺腺癌;miR-155;miR-16;miR-25;miR-133a
作者單位:1天津醫(yī)科大學(xué)腫瘤醫(yī)院,腫瘤研究所腫瘤分子流行病與生物統(tǒng)計(jì)研究室,國(guó)家腫瘤臨床研究中心,天津市腫瘤防治重點(diǎn)實(shí)驗(yàn)室(郵編300060);2天津醫(yī)科大學(xué)研究生院;3上海交通大學(xué)公共衛(wèi)生學(xué)院;4上海交通大學(xué)醫(yī)學(xué)院虹橋國(guó)際醫(yī)學(xué)研究院
肺癌是一種最常見(jiàn)的惡性腫瘤,已位居全部惡性腫瘤發(fā)病率和死亡率的首位[1]。雖然吸煙已被明確認(rèn)為是肺癌的危險(xiǎn)因素,但是肺癌在非吸煙人群中發(fā)病率也呈增加趨勢(shì)[2]。亞洲人群中非吸煙所致的肺癌在整個(gè)肺癌患者占很大的比例。研究證實(shí),表皮生長(zhǎng)因子受體(EGFR)細(xì)胞突變對(duì)表皮生長(zhǎng)因子受體酪氨酸激酶抑制劑(EGFR-TKIs)藥物的反應(yīng)性更好,對(duì)此藥物敏感的患者主要為亞洲非吸煙女性肺腺癌(ADC)者[3]。因此,ADC發(fā)生發(fā)展中進(jìn)行分子標(biāo)志物的研究對(duì)ADC的預(yù)防和治療有重要意義。微小核糖核酸(miRNAs)是一類長(zhǎng)約22個(gè)單位的內(nèi)源性非編碼的單鏈小分子RNA,通過(guò)特異性地與靶基因信使RNA(mRNA)的3′端非翻譯區(qū)互補(bǔ)結(jié)合,可抑制或者降解mRNA的翻譯,進(jìn)而調(diào)控靶基因。越來(lái)越多的研究表明,特定的miRNAs失調(diào)可導(dǎo)致各種疾病,尤其是癌癥的發(fā)生和發(fā)展過(guò)程,包括肺癌[4- 5]。目前,有關(guān)在非吸煙女性ADC患者中
miRNAs和EGFR關(guān)系的研究報(bào)道較少。本研究旨在探討4種miRNAs——miR-155、miR-16、miR-25
及miR-133a在非吸煙女性ADC患者組織中的表達(dá)情況,并分析它們與EGFR突變和預(yù)后的關(guān)系。
1.1一般資料選取2007年7月—2011年8月于天津醫(yī)科大學(xué)腫瘤醫(yī)院行肺癌切除術(shù)的患者組織樣本112例,均經(jīng)肺癌病理確診組織學(xué)類型為ADC。所有患者均為非吸煙女性,年齡34~80歲,平均(57.95±9.81)歲。本研究經(jīng)天津醫(yī)科大學(xué)倫理委員會(huì)認(rèn)可。主要儀器和試劑:總RNA提取試劑Trizol、miRNA特異性逆轉(zhuǎn)錄引物、逆轉(zhuǎn)錄試劑盒、miRNAs特異性TaqManMGB探針引物及TaqMan PCR Master Mix(No UDG)均購(gòu)自美國(guó)應(yīng)用生物系統(tǒng)公司。相關(guān)引物由TaKaRa公司合成,有關(guān)探針序列,見(jiàn)表1。
1.2 miR-155、miR-16、miR-25及miR-133a表達(dá)檢測(cè)(1)提取組織總RNA。取冷存的ADC組織樣本50 mg在液氮中研磨至粉末狀,加1 mL Trizol并按說(shuō)明書(shū)提取總RNA,Nano?Drop 2000c(Thermo公司)微量紫外分光光度計(jì)檢測(cè)RNA濃度和純度,1%瓊脂凝膠電泳鑒定RNA完整性,稀釋到50mg/L,-80℃保存。(2)cDNA合成。根據(jù)試劑盒說(shuō)明書(shū),采用miRNA莖環(huán)結(jié)構(gòu)特異性逆轉(zhuǎn)錄引物和miRNA逆轉(zhuǎn)錄試劑盒進(jìn)行,總反應(yīng)體系為15 μL。逆轉(zhuǎn)錄反應(yīng)條件:16℃30 min,42℃30 min,85℃5 min。cDNA樣本在-20℃保存。(3)實(shí)時(shí)熒光定量PCR。每個(gè)PCR反應(yīng)體系為15 μL,每個(gè)樣本設(shè)3個(gè)復(fù)孔,用ABI Prism7900HT熒光定量PCR儀進(jìn)行TaqMan熒光定量檢測(cè)。反應(yīng)條件:95℃變性10 min;95℃15 s,60℃60 s;50個(gè)循環(huán)。以RUN6B作為內(nèi)參照,以lg2- Ct表示miRNA的相對(duì)表達(dá)量,Ct值為循環(huán)閾值,以內(nèi)參值RUN6B循環(huán)閾值來(lái)標(biāo)準(zhǔn)化, Ct=(CtmiRNA-CtRUN6B), Ct= Ct- Ctmean。

Tab.1 The sequence and assay ID of four miRNAs and RNU6B表1 4種miRNAs及其內(nèi)參照的探針序列
1.3觀察指標(biāo)將112例非吸煙女性ADC患者按EGFR的類型分為EGFR野生型組51例和突變型組61例,比較2組4種miRNAs的表達(dá)差異。對(duì)112例ADC患者進(jìn)行定期隨訪,截止日期為2012年12月,隨訪時(shí)間5~25個(gè)月,中位時(shí)間16個(gè)月,其中10例失訪,隨訪率為91.07%。以miRNAs表達(dá)的平均數(shù)將ADC患者分為miRNAs高表達(dá)組和低表達(dá)組,比較高、低表達(dá)患者間的生存差異。臨床資料中以年齡和EGFR類型進(jìn)行分類納入生存分析。另外,按EGFR類型進(jìn)行分層,由各層的miRNAs表達(dá)的平均數(shù)將ADC患者分為miRNAs高表達(dá)組和低表達(dá)組,比較2組患者間的生存差異。總體生存期(OS)定義為從確診患者為ADC到死亡或隨訪截止日期的時(shí)間。
1.4統(tǒng)計(jì)學(xué)方法采用SAS 9.2統(tǒng)計(jì)軟件進(jìn)行分析。符合正態(tài)分布的計(jì)量資料用x ±s表示,2組間均數(shù)比較行t檢驗(yàn);計(jì)數(shù)資料以例(%)表示,組間比較行χ2檢驗(yàn)。生存分析采用Kaplan-Meier法,用Log-rank法檢驗(yàn)生存率差異。Cox比例風(fēng)險(xiǎn)回歸模型進(jìn)行影響因素分析。以P<0.05為差異有統(tǒng)計(jì)學(xué)意義。
2.1 4種miRNAs在EGFR野生型組和突變型組中表達(dá)情況比較EGFR突變型組miR-25的表達(dá)高于EGFR野生型組(P<0.05);但2組miR-155、miR-16和miR-133a表達(dá)差異無(wú)統(tǒng)計(jì)學(xué)意義,見(jiàn)表2。
Tab. 2 Relationship of four miRNAs in ADC tissue and EGFR表2 4種miRNAs在EGFR野生型組和突變型組的表達(dá)情況?。ā纒)

Tab. 2 Relationship of four miRNAs in ADC tissue and EGFR表2 4種miRNAs在EGFR野生型組和突變型組的表達(dá)情況?。ā纒)
*P<0.05
n組別EGFR野生型組EGFR突變型組t 51 61 miR-155 7.45±0.39 7.43±0.46 0.235 miR-16 7.35±0.37 7.50±0.49 1.939 miR-25 7.30±0.35 7.56±0.41 3.582*miR-133a 7.33±0.46 7.52±0.61 1.868
2.2年齡分層及4種miRNAs高低表達(dá)的生存分析結(jié)果不同年齡分層、不同EGFR類型組、miR-155、miR-16及miR-133a表達(dá)量患者的生存率差異均無(wú)統(tǒng)計(jì)學(xué)意義,miR-25低表達(dá)者生存率較高表達(dá)者更高(P<0.05),見(jiàn)表3、圖1。
2.3不同EGFR類型分層中4種miRNAs高低表達(dá)的生存分析結(jié)果在EGFR突變型組中4種miRNAs的表達(dá)量與ADC預(yù)后無(wú)關(guān)(P>0.05),見(jiàn)圖2、表4;在EGFR野生型組中miR-16、miR-25、miR-133a低表達(dá)者較高表達(dá)者生存率更高(P<0.05),見(jiàn)圖3、表4。2.4非吸煙女性ADC患者影響因素分析以年齡(歲, 60=0,>60=1),EGFR突變類型(野生型=0,突變型=1),4種miRNAs(低表達(dá)=0,高表達(dá)=1)為自變量,患者生存時(shí)間及結(jié)局(生存=0,死亡=1)為因變量,Cox比例風(fēng)險(xiǎn)回歸分析顯示,miR-25高表達(dá)是非吸煙女性ADC患者預(yù)后死亡的獨(dú)立危險(xiǎn)因素,見(jiàn)表5。

Tab. 3 Survival analysis results of 112 non-smoking female patients with ADC表3 112例非吸煙女性ADC患者的生存分析結(jié)果

Fig.1 Comparison of survival rates between different ages, EGFR types and four miRNAs expression levels (Kaplan-Meier method)圖1不同年齡、EGFR類型及4種miRNAs表達(dá)水平生存率比較(Kaplan-Meier法)
根據(jù)世界衛(wèi)生組織(WHO)的統(tǒng)計(jì),約25%的肺癌發(fā)生在非吸煙人群中[6]。歐洲癌癥登記處的數(shù)據(jù)顯示肺癌位居世界上非吸煙者死因中的前10位,女性癌癥死亡的第9位[7]。EGFR是一種跨膜受體型酪氨酸激酶,在非小細(xì)胞肺癌中存在過(guò)表達(dá)和突變現(xiàn)象。EGFR-TKIs靶向治療的一個(gè)必要前提是肺癌患者EGFR酪氨酸激酶編碼區(qū)發(fā)生突變[8]。本研究結(jié)果顯示,非吸煙女性ADC患者中EGFR的突變率(54.5%),明顯高于西方人群[3],再次證實(shí)亞洲非吸煙女性ADC患者是EGFR-TKIs靶向治療的優(yōu)先人群。

Fig. 2 Comparison of survival rates between four miRNAs expression levels in EGFR wild type group(Kaplan-Meier method)圖2 EGFR突變型組中4種miRNAs表達(dá)水平生存率比較(Kaplan-Meier法)

Fig. 3 Comparison of survival rates between four miRNAs expression levels in EGFR wild type group (Kaplan-Meier method)圖3 EGFR野生型組中4種miRNAs表達(dá)水平生存率比較(Kaplan-Meier法)
miR-25是miR-106b-25-93家族的一員,它位于染色體7q22.1上MCM7基因的13內(nèi)含子上。本研究結(jié)果顯示,EGFR突變型組miR-25的表達(dá)高于EGFR野生型組,而且miR-25低表達(dá)者生存率較高表達(dá)者更高,表明miR-25高表達(dá)患者的預(yù)后不佳,因而,筆者推論miR-25可能是一種致癌基因。但是在已報(bào)道的研究中顯示,miR-25對(duì)腫瘤的影響是復(fù)雜的,在骨肉瘤和胃癌的研究中均發(fā)現(xiàn)miR-25能夠增強(qiáng)細(xì)胞的增殖、遷移和侵襲[9-10]。但在有關(guān)結(jié)腸癌的研究中發(fā)現(xiàn),miR-25抑制了細(xì)胞的增殖和遷移[11]。因此,這進(jìn)一步證實(shí)了miRNAs的表達(dá)存在組織特異性和功能多樣性。
miR-133a為一種腫瘤抑制基因。Cui等[12]研究發(fā)現(xiàn),miR-133a可以通過(guò)靶向EGFR來(lái)調(diào)節(jié)乳腺癌細(xì)胞增殖周期。Song等[13]研究顯示,miR-133a通過(guò)EGFR靶點(diǎn)抑制宮頸癌的體外和體內(nèi)生長(zhǎng),是宮頸癌治療的一個(gè)潛在靶點(diǎn)。另有研究認(rèn)為,miR-133a通過(guò)靶向IGF-1R抑制胃癌細(xì)胞的生長(zhǎng)[14]。miR-16的研究目前較少。Wu等[15]研究顯示,miR-16的高表達(dá)抑制肝癌細(xì)胞的增殖、侵襲和轉(zhuǎn)移。本研究顯示,在EGFR野生型組中miR-133a和miR-16低表達(dá)者較高表達(dá)者生存率更高,而在EGFR突變型組中4種miRNAs的表達(dá)量與ADC預(yù)后無(wú)關(guān),表明在非吸煙女性ADC患者中,特別是EGFR野生型的患者,miR-133a和miR-16具有更好的提示預(yù)后價(jià)值。

Tab. 4 Survival analysis results of four miRNAs in EGFR mutation status表4按EGFR突變類型分層后4種miRNAs的生存分析結(jié)果

Tab. 5 Cox influence factor analysis results of 112 nonsmoking female patients with ADC表5 112例非吸煙女性ADC患者的Cox影響因素分析結(jié)果
miR-155是一種致癌基因,通過(guò)靶向FOXO3a在膠質(zhì)瘤的進(jìn)展中發(fā)揮作用[16]。miR-155通過(guò)QKI的表達(dá)來(lái)調(diào)控結(jié)腸癌細(xì)胞侵襲能力和細(xì)胞周期[17]。另有研究顯示,miR-155的高表達(dá)是直腸癌的一個(gè)預(yù)后指標(biāo)[18]。本研究未顯示miR-155與非吸煙女性ADC患者的預(yù)后有關(guān)。考慮原因?yàn)椋阂环矫婵赡芤驗(yàn)楸狙芯窟x取的患者的范圍較窄,僅局限于非吸煙女性,并沒(méi)有包含男性或者吸煙患者;另一方面可能因?yàn)椴煌±眍愋偷姆伟?duì)miRNA的反應(yīng)不同所致,本研究選取的只是ADC患者,并沒(méi)有包含肺鱗癌等。
綜上所述,miR-25是非吸煙女性ADC的獨(dú)立預(yù)后指標(biāo)。miR-25在非吸煙女性ADC特別是在EGFR野生型的患者中表達(dá)升高,可能提示患者預(yù)后不佳。
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(2015-11-19收稿2015-12-05修回)
(本文編輯陸榮展)
Study on the relationship between expression of miRNAs and receptors of epidermal growth factor in lung adenocarcinoma of non-smoking female
WANG Fumin1, 2, ZHANG Huan1, XU Fangxiu1, QU Jinli1, KONG Jinyu1, QIAN Biyun1, 3, 4
1 Department of Epidemiology and Biostatistics, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China; 2 Graduate School of Tianjin Medical University;3 Public Health, Shanghai Jiao Tong University School; 4 Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine Corresponding Author E-mail: qianbiyun@126.com
Abstract:Objective To determine association between the expression of miR-155, miR-16, miR-25 and miR-133 and epidermal growth factor receptor (EGFR) in lung adenocarcinoma (ADC) samples of non-smoking female, and their clini?cal significance thereof. Methods According to EGFR types, 112 non-smoking female ADC patients were divided into two groups: EGFR wild (n=51) and EGFR mutant (n=61) groups. Expression levels of four miRNAs were detected by real time quantitative PCR. T-test was used to compare differences of four miRNAs expression in two groups. ADC patients were divid?ed into high miRNA expression group and low expression group according to the mean value of miRNAs expression. Logrank test was used to compare the survival difference between the two subgroups. Cox proportional hazards regression analy?sis was performed to determine the association between different ages ( 60,>60), EGFR types, miRNAs expression and over?all survival. Results The expression of miR-25 was significantly higher in EGFR mutant group than that in EGFR wild group (P<0.05). There were no significant differences in the survival rates of patients with different ages, EGFR types, and the expressions of miR-155, miR-16 and miR-133a. Patients with the lower expression of miR-25 had the higher survivaltime than patients with the higher expression of miR-25 (P<0.05). In EGFR mutation group, there was no relationship be?tween four miRNAs and the prognosis of ADC (P>0.05). In EGFR wild group, the lower expression of miR-16, miR-25 or miR-133a was associated with longer survival in ADC (P<0.05). Cox proportional hazards regression analysis revealed that the high expression of miR-25 was an independent risk factor for non-smoking female patients with ADC (P<0.05). Con?clusion miR-25 is an independent prognostic indicator for non-smoking female patients with ADC. High expression of miR-25 is found in non-smoking female patients with ADC, particularly in patients with EGFR wild-type, which may sug?gest apoor prognosis.
Key words:receptor, epidermal growth factor;moking;sex factors;gene expression;lung adenocarcinoma;miR-155;miR-16;miR-25;miR-133a
中圖分類號(hào):R734.2,R730.261.1
文獻(xiàn)標(biāo)志碼:A
DOI:10.11958/20150331
基金項(xiàng)目:國(guó)家自然科學(xué)基金資助項(xiàng)目(81573231);天津市自然科學(xué)基金資助項(xiàng)目(13JCYBJC23100)
作者簡(jiǎn)介:王富民(1988),男,碩士在讀,主要從事腫瘤分子流行病學(xué)研究
通訊作者E-mail: qianbiyun@126.com