Biological activity of probable/possible high‐risk human papillomavirus types in cervical cancer

Abstract

Judging the carcinogenicity of human papillomavirus (HPV) types rarely found in cervical cancer (CxCa) is hindered by lack of studies of their biological activity in cancer tissues. To asses transcriptional activity of HPV types, we have developed ultrashort amplimer, splice-site specific, E6*I mRNA RT-PCR assays for 12 high-risk (HR)-HPV (IARC Group 1) and eight probable/ possible high-risk (pHR)-HPV types (IARC Group 2A/B carcinogens). Previously unreported E6*I splice sites of the six pHR-HPV types 26, 53, 67, 70, 73 and 82 were identified by cloning and sequencing. We analyzed 97 formalin-fixed paraffin-embedded (FFPE) Mongolian CxCa biopsies for presence of HPV DNA by two sensitive genotyping assays, for E6*I transcripts of all HR-/ pHR-HPV types identified and for expression of HPV surrogate markers p16 INK4a , pRb and p53. E6*I of at least one HR-/pHR-HPV was expressed in 94 (98%) of cancer tissues including seven with pHR-HPV types 26, 66, 70 or 82 as single transcribed types. Fifty-eight of E6*I mRNA transcribing cases were analyzable by immunohistochemistry and displayed p16 INK4a overexpression in 57 (98%), pRb downregulation in 56 (97%) and p53 downregulation in 36 (62%) tissues. The newly developed E6*I mRNA RT-PCR assays appeared to be highly sensitive method to analyze HPV transcription in FFPE materials. Our finding of viral oncogene transcription of pHR-HPV types 26, 66, 70 and 82 in cervical tumors, in the absence of any other transcriptionally active HR-type and with p16 INK4a overexpression and pRb downregulation, may support a reassessment of the carcinogenicity classification of these pHR-HPV types.Human papillomaviruses (HPV) with currently more than 150 types defined are a complex group differing in tropism and carcinogenic potential. Detection of HPV DNA in 99.7% of cervical cancer (CxCa) cases has established HPV as an etiological factor for CxCa development. 1,2 Epidemiological studies have demonstrated that 20 mucosal HPV types from five phylogenetically related species of the genus alpha (a5, a6, a7, a9 and a11-termed as ''high-risk clade'') are consistently found as single HPV infections in CxCa worldwide. [3][4][5][6] Based on their frequency in CxCa and available biological data, 12 of these types, i.e., types 16,18,31,33,35,39, 45, 51, 52, 56, 58 and 59 have been defined as carcinogens (IARC Group 1A)-hereafter referred to as high-risk (HR)-HPV. For eight other types, in the high-risk clade, i.e., types 26, 53, 66, 67, 68, 70, 73 and 82, the combination of their low frequency, lack of data on their active transcription and their transforming potential in model systems, has led them to be classified as only probable/possible carcinogens (IARC Groups 2A and 2B)-hereafter referred to as possible highrisk (pHR)-HPV types. 7 In the era of HPV-based cervical cancer precursor screening and of type-specific HPV vaccination, understanding the oncogenic properties of individual

Viral RNA Patterns and High Viral Load Reliably Define Oropharynx Carcinomas with Active HPV16 Involvement

“…INK4a overexpression (43). Thus, our results are in conflict with some reports in the literature in which only very few HPV-positive OPSCC or HNSCC were not showing high p16…”

No Causal Association Identified for Human Papillomavirus Infections in Lung Cancer

“…This assay included all 19 HPV16 DNA-positive tumors alongside seven HPV16 DNA negatives. The second assay utilized a recently developed method to detect HPV typespecific transcripts of the E6 gene (26). This assay was customized to detect transcripts of all HPV types identified in this study (details provided upon request).…”

Judging the carcinogenicity of rare human papillomavirus types

“…These types have been reported as single infections in cervical cancer, 4 with a ratio of single to multiple infections in meta-analytical data that resembles that of Group 1/2A types. 5 In addition, HPV82 is able to immortalize human keratinocytes 6 and HPV26, 73, and 82 have been reported as the only actively transcribed type in ICC 7 and/ or periungual cancer. 8 The 13 Group 1/2A types have been already included in all U.S. Food and Drug Administration (FDA)-approved HPV screening tests.…”