Amplification of human papillomavirus types 16 and 18 in invasive cervical cancer

HPV-related squamous neoplasia of the lower anogenital tract: an update and review of recent guidelines

Squamous cell carcinomas of the lower anogenital tract that are related to human papillomavirus (HPV) infection represent a significant disease burden worldwide. The diagnosis and management of their noninvasive precursors has been the subject of extensive study and debate over several decades, accompanied by an evolving understanding of HPV biology. Recent new consensus recommendations for the pathologic diagnosis of these precursor lesions were published in 2012, the result of the Lower Anogenital Squamous Terminology project cosponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology. Most salient among the new guidelines are the recommendation to switch to a 2-tiered nomenclature (high-grade squamous intraepithelial lesion and low-grade squamous intraepithelial lesion) rather than the traditional 3-tiered "intraepithelial neoplasia" terminology, and the recommendation to expand use of the immunohistochemical marker p16 to distinguish between low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion/intraepithelial neoplasia 2. The goals of the project were to align diagnostic terminology with our knowledge of HPV biology, increase reproducibility, consolidate diverse systems of nomenclature, and ultimately better determine a patient's true cancer risk. The clinical guidelines for screening and management of cervical intraepithelial neoplasia have also been recently updated, most notably with a lengthening of screening intervals. In this review, we focus on the new guidelines put forth for pathologic diagnosis of HPV-related anogenital neoplasia, with discussion of the evidence behind them and their potential implications. We also provide an update on relevant biomarkers, clinical recommendations, and the newest developments relating to cervical neoplasia.

The etiologic role of human papillomavirus in penile cancers: a study in Vietnam

Background:

We investigated the aetiologic role of human papillomavirus (HPV) in 120 penile squamous cell carcinomas (PSCCs) from Vietnam.

Methods:

Human papillomavirus DNA was detected by PCR using SPF10 primers and a primer set targeting HPV-16 E6. The INNO-LiPA HPV genotyping kit was used to determine genotype. Human papillomavirus-16 viral load and physical status were determined by real-time PCR. P16^INK4A protein expression was investigated by immunohistochemistry.

Results:

Human papillomavirus DNA was detected in 27 of 120 (23%) PSCCs. The most frequently detected genotype was HPV-16 (24 of 27 cases, 89%). In 16 of 18 (89%) HPV-16-positive cases, the HPV DNA was considered to be integrated into the host genome. The geometric mean of the HPV-16 viral load was 0.4 copies per cell. P16^INK4A overexpression was significantly related to PSCCs infected with high-risk HPV (P=0.018) and HPV-16 copy numbers (P<0.001).

Conclusion:

Human papillomavirus-16 DNA integration and p16^INK4A overexpression in high-risk HPV detected PSCCs suggested an aetiologic role of high-risk HPV in the development of PSCCs.

HPV-related carcinogenesis: basic concepts, viral types and variants

Human papillomavirus (HPV) constitutes a diverse group of small DNA virus, some extensively studied during the last three decades due to their carcinogenic potential. Persistence of viral infections and uncontrolled expression of E6 and E7 viral oncogenes are critical events in transformation. A surprisingly large number of different HPV types have been identified and classified (>100) and it has been anticipated that almost 200 may exist. HPV types are thought to have originated very early during human evolution and are now defined by their L1 genomic sequence, differing by >10% among them. Importantly, viral types are cell-type specific and usually produce different kinds of lesions, benign or malignant. In addition, these types have co-evolved with their hosts and have generated what we call now intratype variants. Variants of HPV types are found associated with the ethnicity of the populations and have been grouped geographically. It is believed that HPV intratype variants may differ in biological behavior. Recognition of the crucial role that some specific HPV types play in cervical cancer development is highly important for their prevention and implementation of public health strategies to control cervical cancer, still the leading cause of death among cancer patients in many developing nations. Here we review basic concepts of HPV-induced carcinogenesis and molecular differences found among HPV types and intratype variants and discuss their clinical and functional implications.

Effect of HPV-associated p16INK4A expression on response to radiotherapy and survival in squamous cell carcinoma of the head and neck

PURPOSE

A subset of head and neck cancers is associated with the human papillomavirus (HPV). Viral infection is closely correlated with expression of p16(INK4A) in these tumors. We evaluated p16(INK4A) as a prognostic marker of treatment response and survival in a well-defined and prospectively collected cohort of patients treated solely with conventional radiotherapy in the Danish Head and Neck Cancer Group (DAHANCA) 5 trial.

PATIENTS AND METHODS

Immunohistochemical expression of p16(INK4A) was analyzed in pretreatment paraffin-embedded tumor blocks from 156 patients treated with conventional primary radiotherapy alone. The influence of p16(INK4A) status on locoregional tumor control, disease-specific survival, and overall survival after radiotherapy was evaluated.

RESULTS

p16(INK4A) positivity was found in 35 tumors (22%). Tumor-positivity for p16(INK4A) was significantly correlated with improved locoregional tumor control (5-year actuarial values 58% v 28%; P = .0005), improved disease-specific survival (72% v 34%; P = .0006), and improved overall survival (62% v 26%; P = .0003). In multivariate analysis, p16(INK4A) remained a strong independent prognostic factor for locoregional failure (hazard ratio [HR], 0.35; 95% CI, 0.19 to 0.64), disease-specific death (HR, 0.36; 95% CI, 0.20 to 0.64), and overall death (HR, 0.44; 95% CI, 0.28 to 0.68).

CONCLUSION

Expression of p16(INK4A) has a major impact on treatment response and survival in patients with head and neck cancer treated with conventional radiotherapy.

Prevalence of high-risk human papillomavirus types in Mexican women with cervical intraepithelial neoplasia and invasive carcinoma

Background

Prevalence of high risk (HR) human papillomavirus (HPV) types in the states of San Luis Potosí (SLP) and Guanajuato (Gto), Mexico, was determined by restriction fragment length-polymorphism (RFLP) analysis on the E6 ~250 bp (E6-250) HR-HPV products amplified from cervical scrapings of 442 women with cervical intraepithelial neoplasia and invasive carcinoma (280 from SLP and 192 from Gto). Fresh cervical scrapings for HPV detection and typing were obtained from all of them and cytological and/or histological diagnoses were performed on 383.

Results

Low grade intraepithelial squamous lesions (LSIL) were diagnosed in 280 cases (73.1%), high grade intraepithelial squamous lesions (HSIL) in 64 cases (16.7%) and invasive carcinoma in 39 cases (10.2%). In the 437 cervical scrapings containing amplifiable DNA, only four (0.9%) were not infected by HPV, whereas 402 (92.0%) were infected HR-HPV and 31 (7.1%) by low-risk HPV. RFLP analysis of the amplifiable samples identified infections by one HR-HPV type in 71.4%, by two types in 25.9% and by three types in 2.7%. The overall prevalence of HR-HPV types was, in descending order: 16 (53.4%) > 31 (15.6%) > 18 (8.9%) > 35 (5.6) > 52 (5.4%) > 33 (1.2%) > 58 (0.7%) = unidentified types (0.7%); in double infections (type 58 absent in Gto) it was 16 (88.5%) > 31 (57.7%) > 35 (19.2%) > 18 (16.3%) = 52 (16.3%) > 33 (2.8%) = 58 (2.8%) > unidentified types (1.0%); in triple infections (types 33 and 58 absent in both states) it was 16 (100.0%) > 35 (54.5%) > 31 (45.5%) = 52 (45.5%) > 18 (27.3%). Overall frequency of cervical lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%). The ratio of single to multiple infections was inversely proportional to the severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types in HSIL and invasive cancer lesions was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%).

Conclusion

Ninety percent of the women included in this study were infected by HR-HPV, with a prevalence 1.14 higher in Gto. All seven HR-HPV types identifiable with the PCR-RFLP method used circulate in SLP and Gto, and were diagnosed in 99.3% of the cases. Seventy-one percent of HR-HPV infections were due to a single type, 25.9% were double and 2.7% were triple. Overall frequency of lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%), and the ratio of single to multiple infections was inversely proportional to severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types found in HSIL and invasive cancer was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%). Since the three predominant types (16, 31 and 18) cause 77.9% of the HR-HPV infections and immunization against type 16 prevents type 31 infections, in this region the efficacy of the prophylactic vaccine against types 16 and 18 would be close to 80%.

Evaluation of quantity and staining pattern of human papillomavirus (HPV)-infected epithelial cells in thin-layer cervical specimens using optimized HPV-CARD assay

BACKGROUND

Testing for human papillomavirus (HPV) is used in the triage of women with a cervical cytology of atypical squamous cells of undetermined significance (ASCUS). A fluorescent in situ hybridization assay was developed for the detection of HPV using the catalyzed receptor deposition technique (HPV-CARD). In this study, the utility of this assay was tested for the detection of HPV in liquid-based cervical cytology specimens.

METHODS

A total of 195 liquid-based cytology specimens were analyzed using the HPV-CARD assay. The results from the assay were compared with HPV polymerase chain reaction (PCR) and typing results. The number of HPV-infected cells and the staining pattern was correlated with the cytology classification.

RESULTS

A 91% concordance between HPV-CARD and PCR was observed for the detection of high-risk HPV viruses. A 78% concordance was observed for specimens that were negative for HPV. In ASCUS, low-grade squamous intraepithelial lesion (LSIL), and high-grade squamous intraepithelial lesion (HSIL) categories, the average number of HPV-positive cells per slide was 19 cells, 127 cells, and 450 cells, respectively. The number of cells with a punctate staining, suggestive of HPV integration, was 21% in ASCUS, 34% in LSIL, and 46% in HSIL specimens.

CONCLUSIONS

The results of the current study indicate positive correlations between the severity of the disease and the increased overall quantity of HPV-positive epithelial cells in cervical cytology specimens and accumulation of cells with punctate staining suggestive of integrated HPV. In summary, the developed HPV-CARD assay was found to provide novel information regarding the proportion and staining pattern of HPV-infected epithelial cells in different cytologic categories of cervical specimens.

The natural history of cervical HPV infection: unresolved issues

The identification of high-risk human papillomavirus (HPV) types as a necessary cause of cervical cancer offers the prospect of effective primary prevention and the possibility of improving the efficiency of cervical screening programmes. However, for these opportunities to be realized, a more complete understanding of the natural history of HPV infection, and its relationship to the development of epithelial abnormalities of the cervix, is required. We discuss areas of uncertainty, and their possible effect on disease prevention strategies.

Human papillomavirus type 16 integration in cervical carcinoma in situ and in invasive cervical cancer

Integration of human papillomavirus type 16 (HPV-16) into the host DNA has been proposed as a potential marker of cervical neoplastic progression. In this study, a quantitative real-time PCR (qRT-PCR) was used to examine the physical status of HPV-16 in 126 cervical carcinoma in situ and 92 invasive cervical cancers. Based on criteria applied to results from this qRT-PCR assay, HPV-16 was characterized in carcinoma in situ cases as episomal (61.9%), mixed (i.e., episomal and integrated; 29.4%), and integrated (8.7%) forms. In invasive cervical cancer samples, HPV-16 was similarly characterized as episomal (39.1%), mixed (45.7%), and integrated (15.2%) forms. The difference in the frequency of integrated or episomal status estimated for carcinoma in situ and invasive cervical cancer cases was statistically significant (P = 0.003). Extensive mapping analysis of HPV-16 E1 and E2 genes in 37 selected tumors demonstrated deletions in both E1 and E2 genes with the maximum number of losses (78.4%) observed within the HPV-16 E2 hinge region. Specifically, deletions within the E2 hinge region were detected most often between nucleotides (nt) 3243 and 3539. The capacity to detect low-frequency HPV-16 integration events was highly limited due to the common presence and abundance of HPV episomal forms. HPV-16 E2 expressed from intact episomes may act in trans to regulate integrated genome expression of E6 and E7.

Human papillomavirus infections in women seeking cervical Papanicolaou cytology of Durango, Mexico: prevalence and genotypes

BACKGROUND

HPV infection in women from developing countries is an important public health problem. Therefore, we sought to determine the prevalences of HPV infection and HPV genotypes in a female population of Durango City, Mexico. Also to determine whether any socio-demographic characteristic from the women associated with HPV infection exists.

METHODS

Four hundred and ninety eight women seeking cervical Papanicolaou examination in three public Health Centers were examined for HPV infection. All women were tested for HPV DNA PCR by using HPV universal primers. In addition, all positive HPV DNA PCR samples were further analyzed for genotyping of HPV genotype 16, 18 and 33. Socio-demographic characteristics from each participant were also obtained.

RESULTS

Twenty-four out of four hundred and ninety-eight (4.8%) women were found infected by HPV. HPV genotype 16 was found in 18 out of the 24 (75%) infected women. Two of them were also coinfected by HPV genotype 18 (8.3%). In the rest 6 PCR positive women, genotyping for HPV genotypes 16, 18 and 33 were negative.

CONCLUSION

The prevalence of HPV in women of Durango City is low; however, most infected women have high risk HPV genotype. The women who were studied showed low frequency of risk factors for HPV infection and this may explain the low prevalence of HPV infection. The high frequency of high risk HPV genotypes observed might explain the high rate of mortality for cervical cancer in our region.

HPV DNA patterns and disease implications in the follow-up of patients treated for HPV16 high-grade carcinoma in situ

Twenty-five patients with high-grade cervical lesions associated with HPV16 infection were studied at the time of surgical treatment and followed up after conization. Before surgical treatment, the following parameters were analyzed: (1) physical status of HPV16 DNA, (2) viral load, (3) cytological presentation confirmed by histological diagnosis, and (4) colposcopy. At the time of conization, (5) margin presentation, and (6) cone biopsy were evaluated. At each stage of the follow-up (7) physical status of HPV16 DNA, (8) viral load, (9) cytological test, and (10) colposcopy were repeated. The correlation between the different parameters was examined. Significant differences in the viral loads were observed between integrated and episomal forms and between the coexisting integrated/episomal forms and the only episomal form, while no statistically significant differences were observed between integrated and coexisting forms. At the first stage of follow-up, 11 of 25 patients analyzed (44%) were negative to HPV DNA cytology and colposcopy tests, 13 of the 25 (52%) were HPV16 DNA negative, 17 (68%) cytology negative, and 20 (80%) colposcopy negative. At the closing stage, 15 of 25 subjects (60%) were negative to all three tests, 16 of the 25 (64%) were HPV16 DNA negative, 19 (76%) cytology negative, and 20 colposcopy negative (80%). These observations suggest that in surgery treated patients the viral clearance at the closing stage of follow-up was unrelated to the HPV DNA physical status and to the viral load before treatment, but was associated significantly with the effectiveness of surgery treatment, in particular with margin cone presentation.

Physical status of HPV-16 in esophageal squamous cell carcinoma

BACKGROUND

Infection with high-risk human papillomavirus (HPV) has been implicated as one of the risk factors of esophageal squamous cell carcinoma (ESCC). Integration of viral DNA into host genome is essential for carcinogenesis since it promotes disruption of the HPV E2 gene, leading to abnormal expression of E6 and E7 oncoproteins.

OBJECTIVES AND STUDY DESIGN

To investigate the viral integration status of HPV-16 infection in ESCC, 35 HPV-positive ESCC specimens collected from Chinese patients were subject to real-time quantitative PCR for determination of physical status of HPV-16 by analyzing the ratios of E2 to E6 genes.

RESULTS

Our results showed that only 8.6% (3/35) of the HPV-16 positive specimens harbored exclusively the episomal form (i.e. E2/E6 ratio > or = 1), whereas the remaining 91.4% contained either only the integrated form (5.7%, with E2/E6 ratio = 0) or a mixture of episomal and integrated forms of viral molecules (85.7%, with E2/E6 ratios > 0 but < 1). Amongst the 30 cancer specimens carrying mixed integrated and episomal forms, 28 had E2/integrated E6 ratios of less than 1, indicating a predominance of integrated form of viral genes in these lesions.

CONCLUSION

Our finding of frequent integration of viral DNA in the host genome suggests that integration HPV-16 is common in ESCC from Chinese patients and implies that HPV infection may play a role in the pathogenesis of ESCC.

Enhanced oncogenicity of Asian-American human papillomavirus 16 is associated with impaired E2 repression of E6/E7 oncogene transcription

Asian-American (AA) variants of human papillomavirus 16 (HPV-16) are linked to a high incidence of cervical cancer in Mexico, with some evidence strongly suggesting that they are more oncogenic than European (E) variants, including their association with younger women and their higher associated risk of cervical cancer. Differences in the regulation of viral E6/E7 oncogene transcription by the E2 protein may be involved in the higher oncogenicity of AA variants. In E variants, E6/E7 oncogene transcription is repressed by the E2 protein and is frequently up-regulated by the destruction of the E2 gene during viral integration. In contrast, the E2 gene is retained in full in most AA-positive carcinomas, raising the possibility of alternative mechanisms for increasing viral oncogene transcription. The authors investigated whether the higher oncogenicity of AA variants is linked to differences in E6/E7 oncogene transcription and the mechanism of E2 deactivation. E6/E7 and E1/E2 transcripts were explored by RT-PCR in 53 HPV-16-positive cervical carcinomas, 39 retaining (20 European and 19 AA) and 14 having lost (12 European and 2 AA) the E1/E2 genes, and transcription repression activity of the AA E2 genes was tested in four cell lines that constitutively express the β-galactosidase reporter or E6/E7 genes driven by the viral long control region. E6/E7 oncogene transcripts were found in all carcinomas, but only those positive for AA variants with E1/E2 genes had complete E2 transcripts. E2 transcripts were down-regulated by splicing in E-positive carcinomas retaining E1/E2. AA E2 genes were impaired for repression of E6/E7 oncogene transcription in vivo. These results suggest that E6/E7 oncogene expression starts earlier in AA than E variant infections, since E variants need E2 to be destroyed or down-regulated.

The prevalence of the HPV 16 genome, integrated viral status and p53 genotype in cervical cancer population of north-eastern Hungary, the correlation with the established markers of tumour progression

OBJECTIVES

To evaluate the prevalence of the HPV 16 integrated status and the p53 genotype in cervical cancer in north-eastern Hungary and their correlation with the established prognostic factors.

STUDY DESIGN

Parallel with the routine histological examination, Southern blot hybridisation and multiplex PCRs were used to detect type/physical state of HPV DNA in primary tumours and in regional lymph nodes combined with p53 genotyping of 83 patients.

RESULTS

46.9% (39/83) prevalence rate of HPV 16 genome was found. The frequency of viral integration (76.9% in primary tumours and 95.2% in regional lymph nodes) and that of the p53Arg homozygous genotype (64.1%) proved to be higher than reported from other parts of the world. The HPV 16 integration and the p53 genotype, failed to correlate with the FIGO stage and lymphatic spread.

CONCLUSION

The prevalence of the integrated status of the HPV 16 genome combined with homozygous p53Arg genotype is relatively high in Hungary. These factors however failed to show a strong correlation with the established markers of tumour progression.

Biotinyl-tyramide-based in situ hybridization signal patterns distinguish human papillomavirus type and grade of cervical intraepithelial neoplasia

In this study, the prevalence of human papillomavirus integration in cervical intraepithelial neoplasia Grades I, II, and III has been investigated using a highly sensitive biotinyl-tyramide-based in situ hybridization methodology. This method is able to demonstrate integrated viral DNA by punctate signals within the nucleus and episomal viral DNA by a diffuse signal throughout the nucleus. Fifteen viral types were identified by General Primer 5+/6+ polymerase chain reaction assay among 26 Grade I and 22 Grade II/III lesions. High-risk human papillomavirus (Types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 66) was found in 20 (77%) Grade I and in 22 (100%) Grade II/III lesions (P =.025). Human papillomavirus Type 16 was identified in 2 (7%) Grade I and in 15 (68%) Grade II/III samples (P <.0001) and was distinguished from other high-risk types by its demonstration in both Grade I and Grade II/III lesions as frequent punctate signals, detectable at all levels of the epithelium including the basal layer. In contrast, punctate signals, when detected among Grade I lesions that were positive for other high-risk types, did not involve the basal layer and were restricted to occasional cells in the superficial layers. However, Grade II/III lesions positive for high-risk types other than human papillomavirus Type 16 demonstrated frequent punctate signals throughout the epithelium. Overall, punctate signals were detected in 22 (100%) high-risk human papillomavirus-positive Grade II/III lesions and in 5 (25%) high-risk positive Grade I lesions (P <.0001). These data are consistent with human papillomavirus Type 16 possessing a high potential for integration, which may explain its frequent association with cervical intraepithelial neoplasia Grade III and carcinomas. Acquisition of the punctate correlate, especially in the basal layer, is also indicated as important in the development of Grade II/III lesions. The data illustrate the unique potential of biotinyl-tyramide-based in situ hybridization to address key issues concerning the biology of cervical intraepithelial neoplasia.

Endocrine tumors of the cervix: morphologic assessment, expression of human papillomavirus, and evaluation for loss of heterozygosity on 1p,3p, 11q, and 17p

BACKGROUND

Cervical endocrine tumors are rare lesions, with a varied diagnostic nomenclature. A recent consensus meeting proposed a standardized terminology. This study evaluated: 1) applicability of histopathologic guidelines; 2) evidence of loss of heterozygosity (LOH) at selected sites; and 3) the presence of human papillomavirus (HPV) detected by nonisotopic in situ hybridization (ISH).

METHODS

Thirty-eight cases (patient age range, 19-88 years; mean, 48 years) were retrieved. Outcome data were available for 32 patients. Classification was based on architectural and cytologic features. Tissue was available from 15 cases for LOH analysis with D3S1234(3p14), D3S1289(3p21), THRB(3p24), TP53(17p13), D1S468(1p36), and INT-2(11q13). In ten cases, tissue was analyzed by nonisotopic ISH with HPV probes for types 6/11, 16/18, and 31/33.

RESULTS

Tumors were divided into four groups: small cell carcinoma (SCC) (n=25); large cell neuroendocrine carcinoma (LCNC) (n=5); SCC with focal LCNC differentiation (n=3), and carcinoid tumor (n=5). Tumors defined as exclusively or predominantly SCC had a particularly poor prognosis, with 20 patients dead of disease (<6 years after diagnosis) and 6 alive with disease (after <3 years of follow-up). LOH at various 3p loci (3p14, 3p21, and 3p24) was observed in eight cases. One patient demonstrated LOH on 17p(TP53). Eight of ten cases assessed by ISH showed nuclear staining using a combined HPV-16/18 probe.

CONCLUSIONS

Cervical endocrine tumors are highly aggressive and can be subdivided into definable categories. LOH at 3p loci is a frequent finding, as is nuclear staining with a combined HPV-16/18 probe. LOH at 17p(TP53 locus) appears to be relatively uncommon, suggesting that p53 mutations may not be developmentally significant.

Low detection rate of HPV in oral and laryngeal carcinomas

The presence of human papillomaviruses (HPVs) in 38 oral and 16 laryngeal lesions (verrucous hyperplasia, carcinoma in situ and carcinomas) was investigated using the polymerase chain reaction (PCR) technique. All biopsies were fresh frozen and a set of consensus and type-specific primers was used for PCR detection and HPV typing. In oral biopsies a low proportion of HPV-positive cases was found, despite the sensitive techniques. Only one case out of 38, a carcinoma in situ was positive (2.6%). It is thought that this finding reflects a minimal presence of HPV in the oral lesions, but a transient role of virus in the induction of carcinomas cannot be ruled out. Differences in relation to other studies may be geographical and/or methodological. In laryngeal carcinomas (and dysplasias), 3 out of 16 cases were HPV positive. This frequency (19%) concurs with most other studies.

Molecular events in uterine cervical cancer

OBJECTIVE

To review the literature regarding the molecular events which occur in the development of uterine cervical cancer, with particular reference to human papillomavirus (HPV) infection.

METHODOLOGY

Bibliographic searches of Medline and the ISI citation databases using appropriate keywords, including the following: papillomavirus, cervix, pathology, cyclin, chromosome, heterozygosity, telomerase, smoking, hormones, HLA, immune response, HIV, HSV, EBV.

CONCLUSIONS

It has become clear that most cervical neoplasia, whether intraepithelial or invasive, is attributable in part to HPV infection. However, HPV infection alone is not sufficient, and, in a small proportion of cases, may not be necessary for malignant transformation. There is increasing evidence that HPV gene products interfere with cell cycle control leading to secondary accumulation of small and large scale genetic abnormalities. This may explain the association of viral persistence with lesion progression but, in many patients, secondary factors, such as smoking and immune response, are clearly important. However, the mechanisms involved in the interaction between HPV and host factors are poorly understood.

Novel binding sites for regulatory factors in the human papillomavirus type 18 enhancer and promoter identified by in vivo footprinting

The E6 and E7 genes of human papillomaviruses (HPVs) associated with anogenital cancers are largely responsible for the oncogenic activity of these viruses, and regulation of these genes has been intensively studied. Transcription of the E6 and E7 genes is controlled by the viral upstream regulatory region (URR). We have used in vivo footprinting to examine the occupancy by regulatory factors of the HPV type 18 (HPV18) URR enhancer and promoter in the cervical carcinoma cell lines HeLa and C4-II. While corroborating occupancy in vivo of all of the elements previously implicated in the transcriptional control of the HPV18 E6 and E7 genes by in vitro DNase I footprinting, gel retardation assays, and transfection studies, we also detect occupancy in vivo of several enhancer and promoter sequences which have not been previously identified as HPV18 URR regulatory elements. Our data suggest that the HPV18 enhancer and promoter are more densely occupied by DNA-binding proteins than previously thought and raise the possibility that additional, possibly novel factors contribute to transcription of the HPV18 early genes.

Interphase karyotypic analysis of chromosomes 11, 17 and X in invasive squamous-cell carcinoma of the cervix: morphological correlation with HPV infection

Human papillomavirus (HPV) infection has been widely implicated in cervical carcinogenesis, but it appears to be an early event, with other genetic abnormalities being required for biological transformation. In this study, interphase cytogenetic analysis of numerical abnormalities of chromosomes 11, 17 and X was performed on paraffin-embedded tissue sections from 25 invasive squamous-cell carcinomas of the cervix and compared with both histopathological features and the morphological distribution of HPV sequences as determined by in situ hybridisation. Numerical differences between chromosomes were identified in 76% of cases, with underrepresentation of chromosomes 11 and/or 17 relative to X in 64% of the total; 22 of 25 cases were HPV-positive, containing either HPV 16, 18 or 31. There was no relationship between the distribution of viral sequences and chromosomal pattern, suggesting that HPV infection precedes karyotypic changes. Our findings suggest that relative reduction in number of chromosomes 11 and 17 is important in the development of invasive cervical neoplasia and are consistent with the putative presence of relevant tumour-suppressor genes on these chromosomes.

Association of human papillomavirus type 16 integration in the E2 gene with poor disease-free survival from cervical cancer

To determine the clinical relevance of human papillomavirus (HPV) integration and E2 function suggested by in vitro studies, we investigated 50 patients with HPV 16-positive primary cervical carcinoma (stage Ib-IV) diagnosed and treated at one institution. The physical state of HPV was determined by colorimetric in situ hybridization and was not found to vary by stage. Overall, 62% of tumors had integrated HPV, 16% had episomal and 22% had both integrated and episomal. The E1/E2 region was evaluated by 8 separate polymerase chain reactions, which resulted in overlapping products. There was no significant variation in ability to amplify the E1/E2 region with stage. E1/E2 amplification correlated with physical state. Nearly all tumors with episomal or mixed HPV 16 DNA amplified all 8 E1/E2 fragments. Half of the tumors with integrated HPV 16 DNA failed to amplify one or more E1/E2 fragments. Disruptions were most frequent in the E2 region. For all 46 patients receiving curative therapy, the Kaplan-Meier estimate of disease-free survival was determined for those whose primary tumors had amplifiable E2 compared with those lacking one or more E2 DNA fragments. Disruption of E2 was associated with significantly shortened disease-free survival.

Properties of HPV-positive and HPV-negative anal carcinomas

Evidence of human papillomavirus (HPV) can be found in up to 85 per cent of anal carcinomas. In the vulva, a discrete subset of HPV-positive carcinomas which show koilocytic morphology and distinct clinical features has recently been identified (warty carcinoma). The morphological and prognostic features of HPV-positive and HPV-negative anal carcinomas were compared in this study of the tumour distribution of HPV DNA. Vulval and anal neoplasia are similar in many ways and we have also looked to see if their similarity extends to 'warty' morphology in relation to HPV status. Thirty-five resection specimens of anal carcinoma were examined with biotin-labelled probes for HPV 6, 11, 16, and 18 DNA, using a non-isotopic in situ hybridization (ISH) technique. No tumour was found to contain HPV 6, 11, or 18. Twenty-four (72 per cent) showed positivity for HPV 16 DNA. Staining was homogeneous and independent of local squamous, basaloid, or ductal differentiation. The majority of tumours showed staining suggestive of episomal, non-productive HPV infection. HPV-positive tumours were more likely to occur in the anal canal than perianally and to show a mixed squamous and basaloid appearance. No difference between the two groups was found in patient age, presence of adjacent dysplasia, ductal differentiation, or prognosis. There was no correlation between condylomatous tumour morphology and HPV 16 DNA positivity; thus, a subset equivalent to vulval warty carcinoma could not be identified.