加 雄,季 剛,郭震芳
(1.陜西楊凌示范區(qū)醫(yī)院;2.西京醫(yī)院;3.銅川市礦務(wù)局第二人民醫(yī)院)
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MicroRNA-630的表達(dá)與胃癌患者預(yù)后相關(guān)性
加 雄1,季 剛2,郭震芳3
(1.陜西楊凌示范區(qū)醫(yī)院;2.西京醫(yī)院;3.銅川市礦務(wù)局第二人民醫(yī)院)
目的 在眾多microRNAs中,MiR-630在人類惡性腫瘤的多種生物學(xué)功能中具有復(fù)雜的調(diào)控作用,本研究主要探討胃癌患者組織中miR-630的表達(dá)與胃癌患者預(yù)后的關(guān)系。方法 收集236例未接受術(shù)前新輔助化療的胃癌患者腫瘤組織及癌旁組織。用qPCR檢測(cè)miR-630的表達(dá),統(tǒng)計(jì)學(xué)分析其與患者術(shù)后預(yù)后的關(guān)系。結(jié)果 與癌旁組織相比,miR-630的表達(dá)水平在癌組織中高表達(dá),并與胃癌侵襲、淋巴結(jié)轉(zhuǎn)移、遠(yuǎn)處轉(zhuǎn)移和TNM分期相關(guān)。生存分析顯示miR-630高表達(dá)與總體生存差相關(guān)。多因素分析顯示,miR-630是預(yù)測(cè)胃癌術(shù)后生存的獨(dú)立預(yù)后因素。結(jié)論 miR-630在胃癌組織中高表達(dá),與腫瘤進(jìn)展相關(guān),是預(yù)測(cè)胃癌患者術(shù)后生存的獨(dú)立預(yù)后因素。
MiR-630 qPCR TNM 分期
相關(guān)數(shù)據(jù)表明,胃癌發(fā)病率存在地區(qū)差異,中國發(fā)病率比西方國家高[1]。根據(jù)2008年的統(tǒng)計(jì)數(shù)據(jù),我國胃癌發(fā)病率高達(dá)0.029%,成為目前中國第二大癌癥及惡性腫瘤相關(guān)的第三大致死原因,僅2008年就新增464 439例確診病例,死亡352 315例[2-10]。
MicroRNAs(miRNAs)是一類高度保守的單鏈小分子非編碼RNA,被認(rèn)為是通過轉(zhuǎn)錄抑制和裂解mRNA發(fā)揮轉(zhuǎn)錄后基因表達(dá)調(diào)控的內(nèi)源性調(diào)節(jié)因子[11]。MicroRNAs在轉(zhuǎn)錄后水平抑制基因表達(dá),通過與靶mRNA的39個(gè)非轉(zhuǎn)錄區(qū)相結(jié)合,根據(jù)互補(bǔ)堿基配對(duì)的程度,降解mRNA和抑制轉(zhuǎn)錄[12,13]。目前的研究表明,MicroRNAs在發(fā)育、細(xì)胞增殖、分化、凋亡和代謝等多種生物學(xué)功能方面發(fā)揮十分重要的作用[14],同時(shí)也參與惡性腫瘤血管生成、侵襲轉(zhuǎn)移[15]。miRNA的表達(dá)異常與腫瘤的發(fā)生密切相關(guān),依據(jù)它們作用的靶基因不同,一些miRNA發(fā)揮抑癌的作用,而另一些則發(fā)揮促癌的作用。對(duì)miRNA的深入研究能夠?qū)盒阅[瘤的診斷和預(yù)后判斷產(chǎn)生更加深刻的認(rèn)識(shí)[16]。近來有證據(jù)表明,miRNAs在多種惡性腫瘤如胃癌、乳腺癌、結(jié)直腸癌、前列腺癌、肺癌、胰腺癌、慢性淋巴細(xì)胞白血病中表達(dá)下調(diào)[17-19]。在人胃癌中,發(fā)現(xiàn)多種異常表達(dá)的miRNAs,如miR-21、miR-22、miR-23、miR-127、miR-148、miR-202、miR-433,它們多具有抑癌或促癌的作用[20-25]。這些結(jié)果表明,miRNAs在包括胃癌在內(nèi)的惡性腫瘤中發(fā)揮十分重要的作用。針對(duì)特定的miRNA的功能和臨床意義的研究,能夠更加深入地認(rèn)識(shí)相關(guān)miRNA的臨床意義。本研究中,我們檢測(cè)miR-630在胃癌組織標(biāo)本中的表達(dá),并分析其與胃癌患者總體生存的關(guān)系。
1.1 病例資料
收集2007年1月至2008年12月間在第四軍醫(yī)大學(xué)西京消化病院接受胃癌手術(shù)患者的新鮮癌組織標(biāo)本及相對(duì)應(yīng)的正常粘膜組織標(biāo)本236例,所有患者術(shù)前均未接受化療,所有患者均簽署知情同意書。此外,收集18例非腫瘤性病變患者的正常粘膜組織作為對(duì)照。所有組織病理學(xué)結(jié)果均經(jīng)西京醫(yī)院病理科醫(yī)師證實(shí)。所有組織標(biāo)本均在離體后10分鐘內(nèi)放入液氮中保存,用于RNA的提取。同時(shí)收集患者的臨床病理資料如年齡、性別及腫瘤分化程度及TNM 分期等。所有患者術(shù)后至少隨訪5年。總體生存被定義為患者從接受手術(shù)起直至死亡的一段時(shí)間。所有患者的隨訪信息每3個(gè)月更新一次?;颊叩乃劳鼍?jīng)過家庭成員和死亡證明的確認(rèn)。
1.2 qPCR
利用Trizol試劑(Invitrogen,Carlsbad,CA,USA)提取全部癌組織及癌旁組織的總RNA。提取的RNA經(jīng)證實(shí)完整性較好的(OD A260/A280值接近2.0)用于后續(xù)實(shí)驗(yàn)。利用基因特異性引物合成miR-630和RNU44(特異性cDNA)。利用實(shí)時(shí)熒光定量PCR檢測(cè)反轉(zhuǎn)錄產(chǎn)物中hsa-miR-630的表達(dá)。所有樣品檢測(cè)均重復(fù)3次。利用△△CT法計(jì)算miR-630的相對(duì)表達(dá)量(RNU44為內(nèi)參)。利用ABI 7500系統(tǒng)進(jìn)行實(shí)時(shí)熒光定量PCR反應(yīng),用SDS 2.2.2軟件統(tǒng)計(jì)分析結(jié)果。
1.3 統(tǒng)計(jì)學(xué)方法
2.1 MiR-630在胃癌中的表達(dá)情況
我們利用real-time PCR檢測(cè)miR-630在236例胃癌組織及相對(duì)應(yīng)癌旁組織和18例正常胃粘膜組織中的表達(dá)(以RNU44為內(nèi)參)。miR-630在癌組織中的相對(duì)表達(dá)量為8.51±1.63,在癌旁組織的相對(duì)表達(dá)量為3.25±0.63,差異具有統(tǒng)計(jì)學(xué)意義(t=46.240,P=0.0000),提示miR-630在胃癌中可能發(fā)揮促癌作用。我們將miR-630的相對(duì)表達(dá)量高于3.88者認(rèn)為是高表達(dá),低于3.88為低表達(dá)。在236例患者中有138例高表達(dá)(58.47%),98例低表達(dá)(41.53%)。
2.2 MiR-630的表達(dá)與胃癌患者臨床病理參數(shù)的關(guān)系
為進(jìn)一步揭示miR-630在胃癌進(jìn)展過程中的作用,我們分析了胃癌患者臨床病理資料與miR-630表達(dá)的關(guān)系。結(jié)果顯示,與T1和T2期患者相比,T3和T4期患者出現(xiàn)miR-630高表達(dá)的頻率更高(68.3% vs 49.6%,P=0.007);miR-630的高表達(dá)頻率在淋巴結(jié)轉(zhuǎn)移陽性患者(74.2% vs 39.8%,P<0.001)和發(fā)生遠(yuǎn)處轉(zhuǎn)移患者(85.7% vs 54.8%,P=0.002)。此外,miR-630高表達(dá)的頻率隨著患者TNM分期升高而升高(P<0.001)。但miR-630的表達(dá)在不同性別、不同年齡、不同腫瘤分化程度、不同腫瘤部位以及不同lauren分級(jí)的胃癌患者中分布頻率的差異無統(tǒng)計(jì)學(xué)意義(表1)。
表1 胃癌患者臨床病理參數(shù)與miR-630表達(dá)的關(guān)系(%)
Table 1 The relationship between clinical pathological parameters and miR-630 expression in patients with gastric cancer(%)
2.3 MiR-630的表達(dá)與胃癌患者總體生存的關(guān)系
在整個(gè)隨訪期間,236例患者中有130例(55.1%)患者死亡,總體中位生存時(shí)間為48個(gè)月。利用Kaplan-Meier法分析miR-630表達(dá)對(duì)于預(yù)測(cè)胃癌患者術(shù)后總體生存的價(jià)值,結(jié)果發(fā)現(xiàn)與miR-630低表達(dá)的患者相比,miR-630高表達(dá)的患者預(yù)后更差( Log-rankP<0.001,圖1)。由于miR-630低表達(dá)的患者中超過50%的患者在隨訪結(jié)束時(shí)仍存活,因而無法分析miR-630低表達(dá)患者的中位生存時(shí)間,miR-630高表達(dá)患者術(shù)后的中位生存時(shí)間僅34個(gè)月(95% CI:28.2-39.8)。當(dāng)我們把miR-630低表達(dá)患者的死亡風(fēng)險(xiǎn)比(hazard ratio,HR)看作1,那么miR-630高表達(dá)患者的HR是低表達(dá)患者的2.28倍(95% CI:1.57-3.32;P<0.001)。由于單因素分析miR-630表達(dá)與胃癌患者術(shù)后總體生存相關(guān),我們進(jìn)一步分析miR-630的表達(dá)是否是影響胃癌患者術(shù)后生存的獨(dú)立預(yù)后因素,我們將miR-630的表達(dá)、淋巴結(jié)轉(zhuǎn)移及遠(yuǎn)處轉(zhuǎn)移納入多因素Cox風(fēng)險(xiǎn)比例模型,性別、年齡、TNM分期等變量作為校正變量。結(jié)果表明,miR-630高表達(dá)的患者經(jīng)校正后的 HR為3.51(95%CI:1.83-6.72;P<0.001)。這些結(jié)果表明miR-630是預(yù)測(cè)胃癌患者術(shù)后總體生存的獨(dú)立預(yù)后因子,miR-630表達(dá)增高的患者預(yù)后較差(表2)。
圖1 miR-630表達(dá)與胃癌患者術(shù)后總體生存關(guān)系圖
Figure 1 miR-630 expression for predicting overall survival of postoperative gastric cancer patients
表2 miR-630表達(dá)和臨床各因素與胃癌患者術(shù)后總體生存的關(guān)系
Table 2 The relationship between miR-630 expression and clinical factors with overall survival in postoperative patients with gastric cancer
最近的研究表明,目前發(fā)現(xiàn)的miRNA超過1900種,在哺乳動(dòng)物中,這些miRNA調(diào)控了超過60%的基因表達(dá)[26]。由于它們?cè)诨虮磉_(dá)調(diào)控方面的重要性,目前認(rèn)為miRNA參與了多種細(xì)胞功能的調(diào)節(jié),如增殖、凋亡和分化,因此miRNAs在從發(fā)育到癌癥等多種生理和病理過程中發(fā)揮十分重要的作用[27-29]。一項(xiàng)在一期非小細(xì)胞肺癌中發(fā)現(xiàn)miRNAs能夠預(yù)測(cè)患者術(shù)后復(fù)發(fā)的研究表明,在1 000種miRNA中,mir-630是一種預(yù)測(cè)復(fù)發(fā)最常用的miRNA之一[30]。另一項(xiàng)在非小細(xì)胞肺癌中的研究表明,miR-630調(diào)控順鉑誘導(dǎo)的腫瘤細(xì)胞死亡,提示miR-630在非小細(xì)胞肺癌中是調(diào)節(jié)順鉑反應(yīng)性的潛在調(diào)節(jié)因子[31]。此外,MiR-630還被發(fā)現(xiàn)在頭頸鱗癌順鉑化療后表達(dá)上調(diào),并且調(diào)控ATG5、ATG6/BECN1、ATG10、ATG12、ATG16L1和UVRAG的表達(dá)[32,33]。最近的研究證實(shí),在胰腺癌細(xì)胞中上調(diào)miR-630的表達(dá)能夠通過IGF-1R誘導(dǎo)凋亡[34]。由于不同的miRNAs在不同的腫瘤組織中作用的靶基因不同,因而miRNAs在不同腫瘤中的功能不同。因此,對(duì)特定miRNAs功能的研究能夠加深對(duì)腫瘤復(fù)雜性基因表達(dá)調(diào)控的理解。
在本研究中,我們利用real-time PCR檢測(cè)了236例術(shù)前未接受新輔助化療胃癌患者組織標(biāo)本中miR-630的表達(dá),基于相對(duì)表達(dá)量檢測(cè)的結(jié)果,我們進(jìn)一步分析了miR-630的表達(dá)與患者臨床病理參數(shù)和預(yù)后的關(guān)系。結(jié)果表明,與癌旁組織及正常組織相比,miR-630在胃癌組織中高表達(dá),提示miR-630可能參與了胃癌的進(jìn)展。同時(shí)我們發(fā)現(xiàn)miR-630的表達(dá)與胃癌侵襲、淋巴結(jié)轉(zhuǎn)移、遠(yuǎn)處轉(zhuǎn)移和TNM分期呈正相關(guān)。miR-630的高表達(dá)更容易發(fā)生在浸潤深、淋巴結(jié)轉(zhuǎn)移、遠(yuǎn)處轉(zhuǎn)移和TNM分期較晚的患者中,提示miR-630可能參與了胃癌的侵襲和轉(zhuǎn)移。因此,miR-630可能在胃癌的發(fā)生和進(jìn)展過程中發(fā)揮重要作用。
由于miR-630As的表達(dá)被發(fā)現(xiàn)與胃癌侵襲轉(zhuǎn)移相關(guān),考慮到胃癌侵襲轉(zhuǎn)移是影響患者預(yù)后的關(guān)鍵因素,miR-630可能成為潛在的預(yù)測(cè)胃癌患者生存預(yù)后的獨(dú)立因素。我們通過Kaplan-Meier法分析總體生存狀況來評(píng)估m(xù)iR-630在胃癌生存預(yù)后中的價(jià)值。結(jié)果表明,miR-630高表達(dá)的患者總體生存要明顯短于miR-630低表達(dá)的患者,提示miR-630是胃癌患者生存預(yù)測(cè)的一個(gè)預(yù)后因子。我們用Cox風(fēng)險(xiǎn)比例模型進(jìn)一步評(píng)估m(xù)iR-630在胃癌中預(yù)測(cè)預(yù)后的價(jià)值,結(jié)果發(fā)現(xiàn)miR-630的高表達(dá)是預(yù)測(cè)胃癌術(shù)后生存的獨(dú)立預(yù)后因子。這些結(jié)果表明,miR-630成為除TNM分期以外的獨(dú)立預(yù)測(cè)胃癌患者生存預(yù)后的分子標(biāo)記,miR-630高表達(dá)的患者術(shù)后具有更高的復(fù)發(fā)風(fēng)險(xiǎn),于是這部分患者應(yīng)該接受更加積極的治療。這些結(jié)果與在非小細(xì)胞肺癌中的研究結(jié)果一致,提示miR-630在這兩種腫瘤中發(fā)揮的作用相似。于是,miR-630的表達(dá)與胃癌患者術(shù)后生存預(yù)后的正相關(guān)關(guān)系不僅能夠預(yù)測(cè)胃癌患者術(shù)后早期發(fā)生侵襲轉(zhuǎn)移的風(fēng)險(xiǎn),還能夠?yàn)槲覀兩钊肜斫馕赴┣忠u轉(zhuǎn)移的潛在機(jī)制研究提供線索。
綜上所述,miR-630在胃癌中高表達(dá)與腫瘤進(jìn)展相關(guān)。因此,miR-630可能在胃癌的侵襲轉(zhuǎn)移過程中發(fā)揮重要的調(diào)控作用。同時(shí),miR-630可能成為臨床上預(yù)測(cè)胃癌患者術(shù)后生存的重要分子標(biāo)記。特異性抑制miR-630的表達(dá)可能成為胃癌新的治療策略。
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Analysis on the relationship between microRNA-630 expression and prognosis of gastric cancer
Jia Xiong1,Ji Gang2,Guo Zhenfang3
(1.Hospital of Yang Lin Demonstration Area;2.Xi Jing Hospital;3. Second Hospital of Tong Chuan for Bureau of Mines)
Objective microRNAs are noncoding RNAs that regulate multiple cellular processes during cancer progression.Among various microRNAs,miR-630 has recently been identified to be implicated in many critical processes in human malignancies.We aimed to investigate the significance and prognostic value of miR-630 in human gastric cancer.Methods Gastric cancer and adjacent normal specimens from 236 patients who had not received chemotherapy were collected.The expression of miR-630 was investigated by quantitative real-time PCR assay and its association with cancer prognosis was analyzed by statistical analysis.Results miR-630 expression level was significantly increased in gastric cancer compared with adjacent normal specimens.It showed that miR-630 expression was associated with gastric cancer invasion,lymph node metastasis,distant metastasis and TNM stage.In addition,survival analysis proved that elevated miR-630 expression was associated with poor prognosis of patients.Multivariate survival analysis also proved that miR-630 was an independent prognostic marker for postoperative survival of patients with gastric caner.Conclusions Higher expression of miR-630 is associated with tumor progression and it may be an independent prognostic factor for postoperative patients with gastric cancer.
MiR-630 qPCR TNM staging
R656.6
A
10.13452/j.cnki.jqmc.2016.03.008
2015-12-13
加雄(1975~),男,漢族,陜西籍,主治醫(yī)師
中國高原醫(yī)學(xué)與生物學(xué)雜志2016年3期