Evidence That Alpha-9 Human Papillomavirus Infections are a Major Etiologic Factor for Oropharyngeal Carcinoma in Black South Africans
Evidence That Alpha-9 Human Papillomavirus Infections are a Major Etiologic Factor for Oropharyngeal Carcinoma in Black South Africans
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DOI：
10.1007/s12105-013-0453-0
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发表时间：
2013-12-01
影响因子：
2.1
通讯作者：
Cooper, Kumarasen
中科院分区：
文献类型：
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作者：
Paquette, Cherie;Evans, Mark F.;Cooper, Kumarasen
人乳头瘤病毒（HPV）感染，最常见的是α-9家族的基因型16，与全世界口咽鳞状细胞癌（OPSC）的病因有关。关于南非OPSC的数据很少，三项先前的研究表明HPV没有显着的病因作用。我们旨在通过聚合酶链反应（PCR）方法，通过测序、原位杂交（ISH）和p16（INK 4a）免疫组织化学（IHC）确定HPV亚型，作为HPV驱动肿瘤的替代标志物，调查南非黑人OPSCs中HPV病因学的证据。假设HPV驱动的肿瘤通过PCR加IHC和/或ISH将是阳性的，而具有HPV背景感染（HPV-过客）的OPSC通过单独PCR将是阳性的。从2005年至2010年收集的来自41名患者的51个OPSC的福尔马林固定的石蜡包埋组织通过GP 5 +6+ PCR（靶向HPV L1区域）、pU-1 M/pU 2 R PCR（靶向HPV E6/E7区域）和HPV-31特异性PCR（靶向E5区域）、显色ISH和p16（INK 4a）IHC分析HPV。所有PCR阳性病例均行测序，确定HPV基因型。患者平均年龄为58.0岁，88%为男性。在51个可评估的肿瘤中，48个（94.1%）通过PCR检测为HPV DNA阳性：25个（49.1%）符合HPV驱动肿瘤的标准，23个（45.1%）符合HPV乘客的标准，3个（5.9%）与HPV无关。PCR阳性病例的测序显示了以下基因型：HPV-16和31的组合（41.7%），HPV-31（25.0%），HPV-16（22.9%），HPV-16和18的组合（6.3%），以及HPV 18和HPV 33各1例。通过ISH的研究在所有病例中均为阴性。根据全球趋势，但与先前的南非数据相反，HPV可能在南非黑人OPSC的重要子集（至少49.1%）中发挥病因学作用。我们发现，α-9 HPV家族，特别是HPV-16和31，无论是组合还是单独，在我们的样本肿瘤中占主导地位。多重PCR引物的使用增加了病毒检测的灵敏度，HPV-31特异性引物证实了许多样本中存在这种基因型。需要进一步的研究，包括HPV E6/E7 mRNA检测，以更好地阐明HPV在南非黑人OPSC中的致病作用。
Human papillomavirus (HPV) infection, most commonly genotype 16 of the alpha-9 family, is implicated in the etiology of a subset of oropharyngeal squamous cell carcinomas (OPSC) worldwide. Data are scarce regarding OPSC in South Africans, and three prior studies suggest no significant etiologic role for HPV. We aimed to investigate for evidence of HPV etiology in OPSCs from black South Africans by polymerase chain reaction (PCR) methodologies with determination of HPV subtype by sequencing, in situ hybridization (ISH), and p16(INK4a) immunohistochemistry (IHC), as a surrogate marker for an HPV-driven tumor. It was hypothesized that HPV-driven tumors would be positive by PCR plus IHC and/or ISH whereas OPSCs with HPV background infections (HPV-passenger) would be positive by PCR alone. Formalin-fixed, paraffin-embedded tissues from 51 OPSCs collected between 2005 and 2010 from 41 patients were analyzed for HPV by GP5+6+ PCR (targeting the HPV L1 region), pU-1M/pU2R PCR (targeting the HPV E6/E7 region) and HPV-31 specific PCR (targeting the E5 region), chromogenic ISH, and p16(INK4a) IHC. All cases positive by PCR were subject to sequencing to determine HPV genotype. The patient mean age was 58.0 years and 88 % were male. Of the 51 evaluable tumors, 48 (94.1 %) were positive for HPV DNA by PCR: 25 (49.1 %) met criteria for an HPV-driven tumor, 23 (45.1 %) for HPV-passenger, and 3 (5.9 %) were HPV-unrelated. Sequencing of the PCR-positive cases revealed the following genotypes: combined HPV-16 and 31 (41.7 %), HPV-31 (25.0 %), HPV-16 (22.9 %), combined HPV-16 and 18 (6.3 %), and a single case each of HPV 18 and HPV 33. Studies via ISH were negative in all cases. In accordance with worldwide trends but contrary to prior South African data, HPV likely plays an etiologic role in a significant subset (at least 49.1 %) of OPSC in black South Africans. We found that the alpha-9 HPV family, particularly HPV-16 and 31 either in combination or separately, to predominate in our sample tumors. The use of multiple PCR primers increased sensitivity of viral detection, and a HPV-31 specific primer confirmed the presence of this genotype in many samples. Further studies including HPV E6/E7 mRNA assays are needed to better elucidate the pathogenic role of HPV in black South African OPSCs.