生物信息學(xué)方法篩選原發(fā)性肝癌早期診斷相關(guān)miRNA

空軍軍醫(yī)大學(xué)(第四軍醫(yī)大學(xué))唐都醫(yī)院傳染病科/全軍感染病診療中心，陜西 西安 710038

【Abstract】ObjectiveTo screen miRNAs by bioinformatics for the early diagnostic tests of primary liver cancer.MethodsThe data of miRNA expression in primary liver cancer tissues were downloaded from the Cancer Genome Atlas (TCGA) database. The expression levels of miRNAs were compared by groupedt-test. miRNAs with a significantly difference of more than 2-time expression levels were enrolled. Target genes of enrolled miRNAs were analyzed based on the miRNA-target analysis tool miRWalk 2.0, and common mutation genes related to primary liver cancer were acquired from c-Bioportal database. MiRNAs whose target genes contained liver cancer related mutation gene were selected, some of which were identified as target miRNAs combined with literature reports.ResultsThe TCGA data included 372 cases of primary liver cancer tissues and 50 cases of normal liver tissues with 1 881 miRNA detected. Forty-one miRNAs increased to more than 2 times in liver cancer tissues, and 115 decreased to more than 1/2. Sixty-eight common mutant genes of primary liver cancer (incidence >5%) were obtained from the c-Bioportal.ConclusionThe bioinformatics method based on TCGA database can easily and reliably screen target miRNAs for follow-up study, which has high popularization value.

【Keywords】 Bioinformatics; Primary liver cancer; Early diagnosis; MicroRNA

miRNA是高度保守、19～25核苷酸長(zhǎng)度的單鏈非編碼RNA，參與調(diào)控機(jī)體發(fā)育、細(xì)胞增殖/分化、細(xì)胞死亡、代謝等生物學(xué)過(guò)程。miRNA種類(lèi)眾多，數(shù)據(jù)庫(kù)miRBase 2014年數(shù)據(jù)表明，僅在人(homo sapiens，HSA)中經(jīng)測(cè)序確定的成熟miRNA序列就有2 588條。miRNA通過(guò)與信使RNA調(diào)控區(qū)的3′或5′非編碼區(qū)序列特異性互補(bǔ)結(jié)合，阻斷mRNA翻譯或促進(jìn)mRNA降解，使相應(yīng)靶基因沉默或低表達(dá)，發(fā)揮基因抑制作用。一種miRNA可作用于多個(gè)靶基因，同一個(gè)基因也可受多種miRNA調(diào)節(jié)，這種網(wǎng)絡(luò)式相互作用增大了miRNA生物學(xué)功能研究的難度，目前主要利用miRNA缺失、低表達(dá)和過(guò)表達(dá)的動(dòng)物模型和細(xì)胞系研究miRNA的確切功能。隨著miRNA生理功能研究的持續(xù)深入，更多新的發(fā)現(xiàn)幫助人們理解生命活動(dòng)，輔助人類(lèi)疾病診療的基礎(chǔ)研究。

鑒于miRNA廣泛、多樣地參與生理、病理過(guò)程，近年來(lái)越來(lái)越多的相關(guān)研究聚焦于miRNA在疾病發(fā)生、發(fā)展、診斷、治療及預(yù)后中的作用。體外實(shí)驗(yàn)、動(dòng)物實(shí)驗(yàn)及患者體內(nèi)miRNA表達(dá)水平變化等研究發(fā)現(xiàn)，miRNA在許多疾病的發(fā)病過(guò)程中發(fā)揮重要作用，如惡性腫瘤、心血管疾病、糖尿病、肥胖、神經(jīng)系統(tǒng)疾病等。如何將miRNA與疾病的臨床管理聯(lián)系起來(lái)是研究熱點(diǎn)，主要方向是惡性腫瘤的早期診斷、慢性疾病的治療監(jiān)測(cè)、預(yù)后預(yù)測(cè)等[6]。近年來(lái)，miRNA作為原發(fā)性肝癌無(wú)創(chuàng)診斷標(biāo)志物的研究很多，顯示出良好的臨床前景，但不同miRNA的診斷效能高低不一，選擇合適的miRNA十分重要[7]。本文擬利用生物信息學(xué)分析，建立一套簡(jiǎn)便而可靠的方法，篩選合適的miRNA用于原發(fā)性肝癌的早期診斷。