Human papillomavirus oncogenic expression in the dysplastic portio; an investigation of biopsies from 190 cervical cones

Abstract

In this study, we investigated the presence of E6/E7 transcripts of seven common high-risk human papillomavirus (HPV) types in 190 cervical biopsies. The RNA-based real-time nucleic acid sequence-based amplification assay (NASBA) and type-specific PCR, both detecting HPV 16, 18, 31, 33, 45, 52, and 58, as well as consensus PCR, were performed on all 190 biopsies. High accordance between type-specific and consensus PCR confirms that the HPV types included in this study are the most common types present in cervical dysplasia. Furthermore, we see a clear increase in the incidence of HPV, both DNA and RNA, along with the histological severity of dysplasia. HPV RNA was detected in all but two PCR-positive cases, confirming that the virus exerts E6/E7 mRNA expression in cases of high-grade dysplasia. Out of 19 women given a normal or borderline diagnosis at conisation, only four were found HPV positive, which may suggest that unnecessary conisations can possibly be reduced by introducing HPV testing into the preoperative routine assessment. Human papillomavirus (HPV) infections are associated with the development of cervical neoplasia and are a necessary factor in the aetiology of cervical carcinoma (Walboomers et al, 1999;Bosch et al, 2002;zur Hausen, 2002). The most frequent HPV types found in high-grade cervical intraepithelial dysplasia (CIN II/III) and in cervical carcinomas are HPV 16, 18, 31, 33, and 45, which are often referred to as high-risk HPV or cancer-associated HPV types. However, the association between a positive HPV DNA test and the risk of subsequent development of dysplasia is partly unknown; the presence of HPV DNA does not necessarily indicate a risk for developing a more severe lesion. In fact, HPV is a very common virus among sexually active women and most infections are transient and asymptomatic (zur Hausen, 1991;Ho et al, 1998;Moscicki et al, 1998). Only very few infections cause morphologic changes in the epithelium and only a small percent of these will eventually develop cervical cancer (Bosch et al, 1995). On the other hand, several studies have shown that in cervical carcinogenesis, the expression of HPV E6 and E7 ORF is required for cell transformation and immortalisation (zur Hausen, 1988;Munger et al, 1989;Stoler et al, 1992). Consequently, persistent expression of these oncogenes may serve as an indicator of progression to CIN and invasive cancer (Sotlar et al, 1998), and detection of E6 and E7 mRNA transcripts may therefore be of higher prognostic value than the detection of HPV DNA. Moreover, new methods for preservation of RNA in cells have made gene expression analysis more feasible.In this study, we investigated the presence of high-risk HPV E6/E7 transcripts in cervical biopsies from patients undergoing conisation. The analysis was performed on a biopsy taken from the ectocervix/transformation zone at the time of conisation, and the pathological diagnosis of this particular biopsy was not always representative for the existing lesion that was later revealed in the cone. This s...

Gene expression reveals two distinct groups of anal carcinomas with clinical implications

“…No other species of HPV was detected by PCR amplification followed by DNA sequencing in these particular biopsies. This does not reflect the distribution of HPV in Norwegian tumour samples reported by others, although HPV16 is reported to be the most common high-risk HPV in Norwegian specimens, accounting for more than 50% of all cases (Kraus et al, 2004;Molden et al, 2005). Owing to the technical limitation of the PCR/sequencing assay, we neither can exclude the presence of other subspecies of HPV within our samples, nor can we exclude the presence of viral variants, sequence disruptions or very low HPV levels that escaped detection by the methods used.…”

Type‐specific human papillomavirus oncogene messenger RNA levels correlate with the severity of cervical neoplasia

“…In this study, there is a significant difference in prevalence of E6 mRNA transcripts between normal and other degrees of cervical lesions, which is consistent with previous reports. 21,28 The geometric mean levels of HPV 16, 18, 52 and 58 E6 mRNA significantly increased from normal and <CIN 1 and CIN 1 to CIN 2þ and CIN 3þ. In contrast, the geometric mean levels of HPV 31 or 33 E6 mRNA did not increase from normal and <CIN 1 and CIN 1 to CIN 2þ and CIN 3þ.…”

“…[8][9][10][11][12][13][14][15]36,37 The overall presence of HPV 16, 18, 52, 58, 31 and 33 E6 mRNA transcripts (68.7%) in the 6 types of HPV DNA-positive cases in CIN lesions is higher than that in a previous study (46%). 21 The presence of these 6 types mRNA transcripts with HPV DNA positive is 80% for CIN 3 but only 13% for normal cytology. Their presence in normal cytology cannot be estimated because only HPV DNA-positive samples in these 6 types have been examined for the presence of mRNA.…”

“…Few studies concerning the extent of oncogenic expression in cervical neoplasia have been published. 21,22 Only a small proportion of HPV DNA-positive women with a normal, atypical squamous cell of uncertain significance or LSIL diagnosis have detectable mRNA expression. 18 HPV DNA testing will not discriminate between active, latent and transient infections.…”

Oral HPV Infection: Current Strategies for Prevention and Therapy

“…Over 90% of these conditions are HPV-positive; in some cases, the genome is only present in episomic or integrated form, in other cases, the complete virions are visible by electronic microscope [45,[60][61][62][63][64].…”