Wang Jian Yan, Liu Danqing, Di Meng Ying, Guo Ying Yuan, Zhao Ming
Department of Otorhinolaryngology Head and Neck Surgery, Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China.
Department of Otorhinolaryngology Head and Neck Surgery, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510000, P.R. China.
Oncol Lett. 2020 Oct;20(4):65. doi: 10.3892/ol.2020.11926. Epub 2020 Jul 29.
Laryngeal carcinoma is a common head and neck malignancy, however, the molecular mechanism of the disease has not yet been elucidated. The present study aimed to investigate the role of IGF1R antisense imprinted non-protein coding RNA (IRAIN) long non-coding (lnc)RNA in laryngeal carcinoma. In total, specimens of healthy pharynx tissue from 6 healthy individuals, carcinoma tissue and paracancerous tissue from 37 patients with laryngeal carcinoma were used in this study. The single nucleotide polymorphism (SNP) rs8034564 was used to distinguish the two parental alleles of IRAIN. DNA and RNA were extracted from tissue specimens and the IRAIN allelic gene was sequenced. Reverse transcription-quantitative PCR was used to determine the expression levels of IRAIN and Insulin-like growth factor 1 receptor (IGF1R) in laryngeal carcinoma and paracancerous tissue. Bisulfite genomic sequencing was used to determine IRAIN promoter DNA methylation status in laryngeal carcinoma tissue. The expression of IRAIN was di-allelic in healthy pharynx tissue, laryngeal carcinoma tissue and paracancerous tissue. Moreover, IRAIN expression in laryngeal carcinoma tissue was lower compared with paracancerous tissue (P<0.05). IRAIN expression was not associated with age, histological type, tumor stage and grade and lymph node metastasis. IRAIN allelic expression imbalance was present in laryngeal carcinoma and paracancerous tissue, but not in healthy pharynx tissue. SNP analysis (rs8034564) indicated there was an allelic-switch of the two parental alleles. Furthermore, epigenetic analysis revealed no extensive DNA methylation of CpG islands in the IRAIN gene promoter of laryngeal carcinoma. Therefore, it was suggested that IRAIN allele was non-imprinted in laryngeal carcinoma and healthy pharynx tissue. It was also demonstrated that IRAIN may be a potential tumor suppressor in laryngeal carcinoma, and that DNA methylation is not involved in the regulation of IRAIN gene immobilization in laryngeal carcinoma tissue. Thus, detection of IRAIN allelic expression imbalance and aberrant allele-switch may serve as an early diagnostic marker of laryngeal carcinoma.
喉癌是一种常见的头颈部恶性肿瘤，然而，该疾病的分子机制尚未阐明。本研究旨在探讨胰岛素样生长因子1受体反义印记非蛋白质编码RNA（IRAIN）长链非编码（lnc）RNA在喉癌中的作用。本研究共使用了6名健康个体的健康咽组织标本、37例喉癌患者的癌组织和癌旁组织。单核苷酸多态性（SNP）rs8034564用于区分IRAIN的两个亲本等位基因。从组织标本中提取DNA和RNA，并对IRAIN等位基因进行测序。采用逆转录定量PCR法检测喉癌组织和癌旁组织中IRAIN和胰岛素样生长因子1受体（IGF1R）的表达水平。采用亚硫酸氢盐基因组测序法检测喉癌组织中IRAIN启动子DNA甲基化状态。IRAIN在健康咽组织、喉癌组织和癌旁组织中的表达为双等位基因。此外，喉癌组织中IRAIN的表达低于癌旁组织（P<0.05）。IRAIN的表达与年龄、组织学类型、肿瘤分期、分级及淋巴结转移无关。喉癌组织和癌旁组织中存在IRAIN等位基因表达失衡，而健康咽组织中不存在。SNP分析（rs8034564）表明两个亲本等位基因存在等位基因转换。此外，表观遗传学分析显示喉癌IRAIN基因启动子中CpG岛无广泛DNA甲基化。因此，提示IRAIN等位基因在喉癌组织和健康咽组织中无印记。研究还表明，IRAIN可能是喉癌潜在的肿瘤抑制因子，且DNA甲基化不参与喉癌组织中IRAIN基因固定的调控。因此，检测IRAIN等位基因表达失衡和异常等位基因转换可能作为喉癌的早期诊断标志物。
