Viral Genetic Engineering Laboratory, Romanian Academy Stefan S. Nicolau Virology Institute, 030304 Bucharest, Romania.
Mol Med Rep. 2011 Jan-Feb;4(1):121-8. doi: 10.3892/mmr.2010.394. Epub 2010 Nov 5.
Cervical cancer is a leading cause of mortality in women. Molecular and epidemiological data have unequivocally confirmed that high-risk human papillomaviruses (HPVs) are a major etiological agent of this malignancy, as host epigenetic alterations are induced in response to viral infection. The present study evaluated the methylation status of CpG islands surrounding miR-124a, miR-34b and miR-203 in 29 cervical cancer precursor lesions, 31 cervical tumors and 30 normal control samples, with the aim of identifying potential markers of cervical cancer. Direct quantitative methylation-specific PCR (qMSP) was used to evaluate the degree of methylation in the samples. HPV DNA was detected and genotyped using the Linear Array HPV Genotyping Test. Data were statistically analyzed using the Kruskal-Wallis test. Differences in miRNA hypermethylation between the tumor and control samples were highly significant for all the genes tested (p<0.0001). Significant results were also obtained regarding the hypermethylation of miR-124a and miR-203 in the precursor lesions compared to the control samples. Among the 29 patients with precursor lesions, 68.97% (20/29) presented high risk (hr)-HPV genotypes and 31.03% (9/29) were diagnosed with low risk (lr)-HPV. Significant results (p=0.0266) were obtained for miR-124a (hr-HPV group, mean 41.32; lr-HPV group, mean 6.74), revealing a strong association between the methylation process and the hr-HPV genotype. Borderline results (p=0.058) were obtained for miR-203 (hr-HPV group, mean 44.05; lr-HPV group, mean 3.33). These results confirm the involvement of epigenetic alterations in cervical oncogenesis. The lr-HPV precursor lesions had a methylation percent pattern similar to that of the normal samples, while the results for the hr-HPV precursor lesions and tumors indicate a possible involvement of the hr-HPV genotype in the miRNA methylation process.
宫颈癌是导致女性死亡的主要原因之一。分子和流行病学数据明确证实，高危型人乳头瘤病毒（HPV）是这种恶性肿瘤的主要病因，因为病毒感染会引起宿主表观遗传改变。本研究评估了 29 例宫颈癌前病变、31 例宫颈癌和 30 例正常对照样本中 miR-124a、miR-34b 和 miR-203 周围 CpG 岛的甲基化状态，旨在寻找宫颈癌的潜在标志物。采用直接定量甲基化特异性 PCR（qMSP）评估样本的甲基化程度。采用线性阵列 HPV 基因分型检测 HPV DNA 并进行基因分型。采用 Kruskal-Wallis 检验对数据进行统计学分析。所有检测基因在肿瘤与对照样本之间的 miRNA 高甲基化差异均具有高度显著性（p<0.0001）。与对照样本相比，前病变中 miR-124a 和 miR-203 的高甲基化也有显著差异。在 29 例前病变患者中，68.97%（20/29）患者携带高危型（hr）HPV 基因型，31.03%（9/29）患者诊断为低危型（lr）HPV。miR-124a（hr-HPV 组，均值 41.32；lr-HPV 组，均值 6.74）的检测结果具有统计学意义（p=0.0266），表明甲基化过程与 hr-HPV 基因型之间存在很强的相关性。miR-203 的检测结果接近统计学意义（p=0.058）（hr-HPV 组，均值 44.05；lr-HPV 组，均值 3.33）。这些结果证实了表观遗传改变在宫颈癌发生中的作用。lr-HPV 前病变的甲基化百分比模式与正常样本相似，而 hr-HPV 前病变和肿瘤的结果表明，hr-HPV 基因型可能参与了 miRNA 甲基化过程。
