Wang De-Zhong, Chen Guan-Yang, Li Yi-Feng, Zhang Neng-Wei
Department of Gastroenterology, Liver and Gallbladder Surgery, Peking University Ninth School of Clinical Medicine, Beijing 100038, China.
The Clinical Center of Gene and Cell Engineering, Beijing Shijitan Hospital, Peking University Ninth School of Clinical Medicine, Beijing 100038, China.
Chin Med J (Engl). 2020 Jun 5;133(11):1312-1321. doi: 10.1097/CM9.0000000000000753.
Rectal cancer (RC) is a malignant tumor that seriously threatens human health. Long non-coding RNAs (lncRNAs) play a vital role in tumor regulation. Nevertheless, their exact expression features and functions remain obscure, and therefore was the aim of the current study.
We utilized the Affymetrix human GeneChip to screen differentially expressed profiles of lncRNAs and mRNAs from the cancer tissues and matched paracancer tissues of 6 RC patients. Gene Ontology (GO) and pathway enrichment analyses identified crucial functions and pathways of the aberrantly expressed mRNAs. We used quantitative real-time polymerase chain reaction to verify the significant expression differences of 11 candidate lncRNAs between the cancer and paracancer tissues. LncRNA-mRNA coexpression networks were built by calculating the Pearson correlation value to identify significant correlation pairs. Online bioinformatics tools GEPIA2, ONCOMINE, and PROGgeneV2 were used to mine the expression and prognosis of three crucial mRNAs and six verified lncRNAs. Competing endogenous RNA networks were constructed by predicting microRNA response elements and calculating free energy.
We found 1658 differentially expressed lncRNAs (778 up-regulated and 880 down-regulated) and 1783 aberrantly expressed mRNAs (909 up-regulated and 874 down-regulated). GO and pathway enrichment analyses revealed the vital functions of the differentially expressed mRNAs, including cell proliferation, cell migration, angiogenesis, and cellular response to zinc ion. The canonical signaling pathways mainly included the interleukin-17, cell cycle, Wnt, and mineral absorption signaling pathways. Six lncRNAs including AC017002.2 (P = 0.039), cancer susceptibility 19 (CASC19) (P = 0.021), LINC00152 (P = 0.013), NONHSAT058834 (P = 0.007), NONHSAT007692 (P = 0.045), and ENST00000415991.1 (P = 0.045) showed significant differences in expression levels between the cancer tissue and paracancer tissue groups. AC017002.2, NONHSAT058834, NONHSAT007692, and ENST00000415991.1 have not yet been reported in RC. The crucial mRNAs myelocytomatosis viral oncogene (MYC), transforming growth factor beta induced (TGFBI), and solute carrier family 7 member 5 (SLC7A5) were selected. AC017002.2 and LINC00152 were positively correlated with MYC, TGFBI, and cytochrome P450 family 2 sub-family B member 6 (All r > 0.900, P < 0.050). NONHSAT058834 was positively associated with MYC (r = 0.930, P < 0.001), and CASC19 was positively correlated with SLC7A5 (r = 0.922, P < 0.001).
This study offers convincing evidence of differentially expressed lncRNAs and mRNAs as potential biomarkers in RC.
直肠癌（RC）是一种严重威胁人类健康的恶性肿瘤。长链非编码RNA（lncRNAs）在肿瘤调控中发挥着至关重要的作用。然而，它们的确切表达特征和功能仍不清楚，因此本研究旨在对此进行探究。
我们利用Affymetrix人类基因芯片筛选了6例直肠癌患者癌组织及配对癌旁组织中lncRNAs和mRNAs的差异表达谱。基因本体论（GO）和通路富集分析确定了异常表达mRNA的关键功能和通路。我们使用定量实时聚合酶链反应来验证11个候选lncRNAs在癌组织和癌旁组织之间的显著表达差异。通过计算皮尔逊相关值构建lncRNA-mRNA共表达网络，以识别显著相关对。使用在线生物信息学工具GEPIA2、ONCOMINE和PROGgeneV2挖掘3个关键mRNA和6个已验证lncRNAs的表达和预后情况。通过预测微小RNA反应元件并计算自由能构建竞争性内源性RNA网络。
我们发现1658个差异表达的lncRNAs（778个上调，880个下调）和1783个异常表达的mRNAs（909个上调，874个下调）。GO和通路富集分析揭示了差异表达mRNA的重要功能，包括细胞增殖、细胞迁移、血管生成以及细胞对锌离子的反应。典型信号通路主要包括白细胞介素-17、细胞周期、Wnt和矿物质吸收信号通路。6个lncRNAs，包括AC017002.2（P = 0.039）、癌症易感性19（CASC19）（P = 0.021）、LINC00152（P = 0.013）、NONHSAT058834（P = 0.007）、NONHSAT007692（P = 0.045）和ENST00000415991.1（P = 0.045）在癌组织和癌旁组织组之间的表达水平存在显著差异。AC017002.2、NONHSAT058834、NONHSAT007692和ENST00000415991.1在直肠癌中尚未见报道。筛选出关键的mRNAs，即髓细胞瘤病毒癌基因（MYC）、转化生长因子β诱导（TGFBI）和溶质载体家族7成员5（SLC7A5）。AC017002.2和LINC00152与MYC、TGFBI和细胞色素P450家族2亚家族B成员6呈正相关（所有r>0.900，P<0.050）。NONHSAT058834与MYC呈正相关（r = 0.930，P<0.001），CASC19与SLC7A5呈正相关（r = 0.922，P<0.001）。
本研究提供了令人信服的证据，表明差异表达的lncRNAs和mRNAs作为直肠癌潜在生物标志物的可能性。
