Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Section of Microbiology, S.Orsola-Malpighi Hospital, University of Bologna, via Massarenti 9, 40138 Bologna, Italy; Unit of Microbiology, Department of Hematology, Oncology and Laboratory Medicine, S.Orsola-Malpighi University Hospital, via Massarenti 9, 40138 Bologna, Italy.
Unit of Otolaryngology, Department of Specialist Surgery and Anesthesiology, S.Orsola-Malpighi University Hospital, via Massarenti 9, 40138 Bologna, Italy.
J Clin Virol. 2014 Jul;60(3):243-9. doi: 10.1016/j.jcv.2014.04.014. Epub 2014 Apr 28.
HPV16 is the most prevalent genotype in oropharyngeal squamous cell carcinomas (OPSCCs), but there are few information about intratype variants prevalence and their clinical relevance in these tumors. Moreover, since HPV DNA detection alone is not sufficient to determine a favorable prognosis for OPSCCs, additional diagnostic/prognostic biomarkers are necessary.
To assess the prevalence of HPV intratype variants and evaluate the role of HPV16 DNA methylation as prognostic marker in OPSCCs.
We analyzed 81 biopsies of OPSCCs for HPV detection and genotyping with a pyrosequencing-based HPV DNA-test. We also quantified viral DNA methylation frequency in the LCR by pyrosequencing in patients with transcriptionally-active HPV16-infection, analyzing it in function of available clinical/virological data.
The overall HPV prevalence was 74.1% and HPV16 was confirmed the most prevalent genotype (51/60, 85.0%). Interestingly, we detected, for the first time, HPV16 African variants in 10/51 cases (19.6%), pointing out their clinical relevance also out of the anogenital district. Regarding viral DNA methylation, the E2BS1 showed a significantly higher mean methylation frequency compared to E2BS3/4, as previously observed in high-grade precancerous lesions of the uterine cervix. On the other hand, patient with a mean methylation frequency in the early promoter >10% showed only a tendency to have a worse prognosis.
Our results highlight both the involvement of HPV16 African variants in OPSCCs development and the necessity of further studies to deepen the role of viral methylation in these tumors, in order to better define similarities/differences compared to cervical cancer.
HPV16 是口咽鳞状细胞癌（OPSCC）中最常见的基因型，但关于这些肿瘤中同型变体的流行率及其临床相关性的信息很少。此外，由于 HPV DNA 检测本身不足以确定 OPSCC 的良好预后，因此需要额外的诊断/预后生物标志物。
评估 HPV 同型变体的流行率，并评估 HPV16 DNA 甲基化作为 OPSCC 预后标志物的作用。
我们使用基于焦磷酸测序的 HPV DNA 检测分析了 81 例 OPSCC 活检标本，以检测和基因分型 HPV。我们还通过焦磷酸测序定量了转录活性 HPV16 感染患者 LCR 中的病毒 DNA 甲基化频率，并根据可获得的临床/病毒学数据分析了其功能。
HPV 的总体流行率为 74.1%，HPV16 被确认为最常见的基因型（51/60，85.0%）。有趣的是，我们首次在 10/51 例（19.6%）病例中检测到 HPV16 非洲变体，这表明它们在肛门生殖器区域外也具有临床相关性。关于病毒 DNA 甲基化，E2BS1 的平均甲基化频率明显高于 E2BS3/4，正如以前在子宫颈高级别癌前病变中观察到的那样。另一方面，平均早期启动子甲基化频率>10%的患者仅显示出预后较差的趋势。
我们的研究结果强调了 HPV16 非洲变体在 OPSCC 发展中的作用，以及进一步研究的必要性，以加深病毒甲基化在这些肿瘤中的作用，以便更好地定义与宫颈癌的异同。
