Transcription patterns of human papillomavirus type 16 in genital intraepithelial neoplasia: evidence for promoter usage within the E7 open reading frame during epithelial differentiation.

Human papillomavirus (HPV) type 16 transcription was analysed by in situ hybridization using 125I-labelled subgenomic riboprobes, from 26 genital intraepithelial neoplastic (IN) lesions, in formalin-fixed biopsies from 18 different cases. Distinct transcription patterns separable by the presence or absence of late gene transcription were detected. In 12 lesions, late gene expression was absent; HPV transcripts corresponding to the E6 and E7 open reading frame (ORF) were detectable in all basal cells and were usually evenly distributed through all layers of the epithelium. Transcripts corresponding to the E1, E2 and E2/E4 ORFs were present in nine of 12 lesions and displayed a similar distribution. In 14 lesions late gene transcripts were present. E6 and E7 transcripts were detectable basally in all but one lesion. The levels of E7 but not E6 transcripts were markedly increased in the superficial cells of differentiating epithelia, with an identical distribution and at similar levels to those of the E2/E4 transcript. We propose that the most abundant transcript in genital IN lesions containing late gene expression is an E7/E1 [symbol: see text] E2/E4 transcript corresponding to that reported in HPV-6/11 condylomata and which is derived from a similar promoter within the E7 ORF.

High prevalence of human papillomavirus transcripts in all grades of cervical intraepithelial glandular neoplasia.

Cervical biopsy specimens containing cervical intraepithelial glandular neoplasia (CIGN) were examined for the presence of human papillomavirus (HPV) RNA transcripts by in situ hybridization with iodine 125-labeled riboprobes. HPV RNA was detectable in 95.2% of biopsy specimens. HPV 16 RNA was present in 12, HPV 18 in 27, and both in 1 of the 42 cases examined. Among HPV-positive cases, HPV RNA was detectable in all grades of CIGN and, in three cases, in glands displaying only minimal nuclear abnormality insufficient for a diagnosis of CIGN. Patients with HPV RNA-positive CIGN were younger than those with negative findings for HPV, and patients with less severe grades of CIGN showed a trend toward a younger age of presentation than patients with severe glandular lesions. Increasing grades of CIGN may reflect progressive stages in the development of cervical adenocarcinoma, and this progression may closely involve HPV gene expression from its earliest stages.

Differing prevalence of human papillomavirus RNA in penile dysplasias and carcinomas may reflect differing etiologies.

Penile intraepithelial neoplasias grade 3 (PIN 3) and penile carcinomas were examined for the presence of human papillomavirus (HPV) RNA transcripts by in situ hybridization using 125I-labeled RNA probes. Human papillomavirus transcripts were detected in all 10 PIN 3 lesions not associated with invasive malignant conditions but were present in only 29% of penile carcinomas (9 of 26 squamous cell carcinomas and none of 5 verrucous carcinomas). Human papillomavirus RNA-positive penile cancers were significantly more likely to exhibit adjacent PIN 3 lesions than were HPV-negative tumors, and PIN 3 lesions adjacent to tumors always contained the same HPV-RNA type as was present in the invasive tumor. The development of most penile cancers may be unrelated to HPV infection. Future epidemiologic studies of the role of sexually transmitted factors in the development of penile carcinoma should distinguish between HPV-positive and HPV-negative penile cancers.

Increased age and mortality associated with cervical carcinomas negative for human papillomavirus RNA.

Attempts to relate presence and type of human papillomavirus in cervical carcinoma with prognosis have yielded conflicting results. To further investigate this relation, the association between survival of cervical cancer patients after diagnosis and the presence of human papillomavirus (HPV) RNA within the tumour was assessed retrospectively. Formalin-fixed biopsy specimens from 212 patients with cervical carcinoma who had been followed for up to 6 years were tested by in-situ hybridisation with 125I-labelled riboprobes. HPV-RNA-positive women were 11.9 years younger than HPV-negative women at diagnosis (p less than 0.001). Case-fatality rates from cervical cancer rose with absence of HPV RNA, age at diagnosis, or FIGO stage. Multivariate analysis confirmed that absence of detectable HPV RNA and advanced FIGO stage were independent risk factors. No differences in survival between HPV types 16, 18, 31, or 33 were seen. These observations suggest that cervical carcinoma patients fall into two groups--a younger, HPV-RNA-positive group, with a better prognosis, and an older, HPV-RNA-negative group with poorer prognosis. Treatment regimens for the two groups may need to differ.

Differing characteristics of human papillomavirus RNA-positive and RNA-negative anal carcinomas.

Anal carcinomas were tested for the presence of human papillomavirus (HPV) RNA transcripts by in situ hybridization using 125I-labeled RNA probes. The HPV transcripts were detected in 73.2% of 41 nonglandular anal carcinomas but in none of six anal or 11 rectal adenocarcinomas. In anal nonglandular carcinomas, no difference in the percentage of tumors that were HPV RNA positive was observed between tumors classed as basaloid carcinomas or squamous cell carcinomas. Patients with HPV RNA-negative tumors were significantly older (9.2 years) than those with HPV RNA-positive tumors. Anal intraepithelial neoplasia Grade 3 in the surrounding epithelium was seen in 14 of 25 assessable HPV RNA-positive tumors and in none of nine assessable HPV RNA-negative tumors. Anal tumors may include two separate clinical and biologic groups distinguished by their dependence, or lack of dependence, on HPV RNA expression for maintenance of the neoplastic state.

Presence and distribution of human papillomavirus sense and antisense RNA transcripts in genital cancers.

RNA transcription in eight human papillomavirus (HPV) type 16-positive genital carcinomas and in two cervical squamous cell carcinoma (SCC)-derived cell lines was analysed by in situ hybridization using 125I-labelled subgenomic riboprobes. Transcripts corresponding to the E6 and E7 open reading frames were always present, except within the keratinizing layers of differentiated SCCs. Intranuclear E1 gene transcripts were detectable in both cell lines and some tumours whereas E2/E4 transcripts were absent from five of seven assessable tumours, suggesting transcription from integrated viral DNA. When mRNA sense riboprobes were used as controls, no signal was seen in the two cell lines; however, three tumours contained a focal, intense nuclear RNase-sensitive signal using mRNA sense riboprobes. This antisense RNA signal mapped across the whole genome including the noncoding region. In one tumour, the presence of antisense RNA was independently confirmed by using E7 and E2/E4 RNA probes of both orientations in RNase protection assays. Transcription of antisense RNA may be a natural feature of some HPV-positive genital tumours and its possible role in modulating cell behaviour in vivo requires further investigation.