Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, Chiba University, Japan; Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Japan.
Department of Molecular Oncology, Graduate School of Medicine, Chiba University, Japan.
Cancer Lett. 2017 Oct 28;407:21-31. doi: 10.1016/j.canlet.2017.08.008. Epub 2017 Aug 18.
Oropharyngeal squamous cell carcinoma (OPSCC) incidence has increased dramatically due to human papillomavirus (HPV); however, associated epigenetic alterations are not well studied. We performed genome-wide DNA methylation analysis using an Infinium 450k BeadArray for clinical OPSCC and non-cancerous samples and cancer cell lines with/without 5-aza-2'-deoxycytidine and/or trichostatin A treatment. Frequent promoter hypermethylation and methylation-associated silencing were detected in 144 genes, which included those involved in cell-cell signaling and neuron differentiation. The methylation of nine genes (GHSR, ITGA4, RXRG, UTF1, CDH8, FAN19A4, CTNNA2, NEFH, and CASR) was quantitatively validated in 70 pharyngeal SCC cases by pyrosequencing. Hypermethylation significantly correlated with HPV-L1 positivity, but not with age or smoking status. p16 was generally activated in HPV-L1(+) tumors, and p16-positive cases significantly associated with better prognosis. RXRG hypermethylation strongly correlated with positivity of HPV-L1 and p16 (P = 3 × 10 and P = 5 × 10, respectively). RXRG-methylation(+) significantly associated with better prognosis when analyzing all tumor cases (P = 0.04), and when analyzing the p16-negative poorer-outcome group (P = 0.03). Thus, aberrant DNA methylation might be involved in HPV-associated OPSCC; in addition, DNA methylation could serve as a marker to classify subgroups based on outcome.
口咽鳞状细胞癌 (OPSCC) 的发病率因人类乳头瘤病毒 (HPV) 的出现而显著增加；然而，相关的表观遗传改变尚未得到很好的研究。我们使用 Infinium 450k BeadArray 对临床 OPSCC 和非癌性样本以及具有/不具有 5-aza-2'-脱氧胞苷和/或曲古抑菌素 A 治疗的癌细胞系进行了全基因组 DNA 甲基化分析。在 144 个基因中检测到频繁的启动子高甲基化和与甲基化相关的沉默，这些基因包括参与细胞间信号转导和神经元分化的基因。在 70 例咽鳞癌病例中，通过焦磷酸测序定量验证了 9 个基因 (GHSR、ITGA4、RXRG、UTF1、CDH8、FAN19A4、CTNNA2、NEFH 和 CASR) 的甲基化。高甲基化与 HPV-L1 阳性显著相关，但与年龄或吸烟状况无关。p16 通常在 HPV-L1(+)肿瘤中被激活，p16 阳性病例与更好的预后显著相关。RXRG 高甲基化与 HPV-L1 和 p16 的阳性率强烈相关 (P 分别为 3×10 和 5×10)。在分析所有肿瘤病例时，RXRG 甲基化阳性与更好的预后显著相关 (P 为 0.04)，在分析 p16 阴性预后较差的组时，RXRG 甲基化阳性与更好的预后显著相关 (P 为 0.03)。因此，异常的 DNA 甲基化可能参与了 HPV 相关的 OPSCC；此外，DNA 甲基化可以作为一种标志物，根据结果对亚组进行分类。
