HPV-mediated transformation of the anogenital tract

Radiation therapy of recurrent anal squamous cell carcinoma in-situ: a case report

Introduction

High-grade anal intraepithelial neoplasia, also referred to as anal squamous carcinoma in-situ, or Bowen's disease of the anus, make up less than 1% of all digestive system cancers in the United States. The treatment of choice is surgical resection with anal mapping. However, this disease often recurs or persists, requiring additional surgery for these patients. This can compromise the anal sphincter leading to leakage. In this case report, we discuss the efficacy of radiation therapy as a modality to treat post-excisional recurrent Bowen's disease, which may prevent sphincter compromise, leading to improved quality of life.

Case presentation

An 84-year-old Caucasian woman presented with post-excisional persistent/recurrent squamous cell carcinoma in-situ. The initial lesion measured 3 cm in diameter on the right lateral side of the anal margin. A standard surgery consisting of wide local excision with anal mapping was performed. The margins were clear and our patient was followed up. Our patient recurred with a 1.2 × 0.8 cm lesion on the left anal verge extending to the anal canal. A biopsy along with mapping was done, and 2 of the 17 mapping specimens were positive for carcinoma in-situ, one in the anal canal. Due to the location of the positive anal mapping, and in order to prevent sphincter compromise on re-excision, our patient was offered definitive radiation therapy. Two years after radiation therapy, our patient showed no signs of recurrent disease and had good sphincter control.

Conclusion

Although the main treatment modality for treating persistent/recurrent Bowen's disease is surgery, an alternative approach using external beam radiation for CIS may be enough to provide a cure for some patients with recurrent disease.

New generic primer system targeting mucosal/genital and cutaneous human papillomaviruses leads to the characterization of HPV 115, a novel Beta-papillomavirus species 3

We explored the cutaneotropic HPV genetic diversity in 71 subjects from Argentina. New generic primers (CUT) targeting 88 mucosal/cutaneous HPV were designed and compared to FAP primers. Overall, 69 different HPV types/putative types were identified, being 17 of them novel putative types. Phylogenetic analysis of partial L1 sequences grouped 2 novel putative types in the Beta-PV, 14 in the Gamma-PV and 1 in the Mu-PV genera. CUT primers showed broader capacity than FAP primers in detecting different genera/species and novel putative types (p<0.01). Using overlapping PCR, the full-length genome of a Beta-PV putative type was amplified and cloned. The new virus, designated HPV 115, encodes five early genes and two late genes. Phylogenetic analysis indicated HPV 115 as the most divergent type within the genus Beta-PV species 3. This report is the first providing data on cutaneous HPVs circulating in South America and expands our knowledge of the Papillomaviridae family.

Knowledge, attitudes, and practices related to Pap test by women, Northeastern Brazil

OBJECTIVE

To assess the knowledge, attitudes and practices of women related to the Pap test and the association between these behaviors and sociodemographic characteristics.

METHODS

A household survey with quantitative approach was conducted. A total of 267 women aged 15 to 69 years, randomly selected in a stratified manner, living in the city of São José de Mipibu, Northeastern Brazil, were interviewed in 2007. A questionnaire consisting of pre-coded open questions was administered and answers were described and analyzed, as for adequacy of knowledge, attitudes, and practices of women regarding the Pap test. Tests of association were carried out between sociodemographic characteristics and behaviors studied at a 5% significance level.

RESULTS

Although 46.1% of the women interviewed showed adequate knowledge about the Pap test, a significantly higher proportion of adequacy was seen regarding attitudes and practices, 63.3% and 64.4%, respectively. Higher schooling was associated with adequacy of knowledge, attitudes, and practices. The main barriers to the Pap test were negligence, non-requesting by their physicians, and shame.

CONCLUSIONS

The physician is the main source of information about the Pap test. However, women who more often attend medical visits, despite their good practice, show low adequacy of knowledge and attitudes related to the Pap test, which indicates that they are not receiving appropriate information on the test's purpose, advantages and benefits to women's health.

Primary melanomas of the esophagus and anorectum: epidemiologic comparison with melanoma of the skin

The objective of this study was to use recently available data to describe the epidemiology of melanomas of the esophagus and the anorectum in contrast to melanoma of the skin. The methods used include descriptive epidemiology using cases reported to the Surveillance Epidemiology and End Results registry, 1973-2003. All rates were age adjusted. We found 46 759 cutaneous melanomas, 170 anorectal melanomas and 20 esophageal melanomas, corresponding to age-adjusted rates of 70.1, 0.27, and 0.03 per million population, respectively. Median age of patients with melanoma of the skin was less than those with melanoma of the anorectum or esophagus (55 years vs. 71 years and 69 years, respectively). Rates of melanoma of the skin were 1.5-fold higher for men than for women (87.1 vs. 58.1 per 10); in contrast, rates of anorectal melanoma were 1.6-fold higher for women than for men (0.324 vs. 0.199 per 10). Rates of cutaneous melanoma for whites were 13-fold higher than for blacks (80.6 vs. 6.1 per 10, P<0.001), whereas the rates of anorectal melanoma were 1.7-fold higher among whites than blacks (0.273 vs. 0.173 per 10). Comparing the period 1973-1987 with 1988-2003, the rate of cutaneous melanoma increased 1.4-fold (56.0-80.1 per 10), whereas the rate of anorectal melanoma similarly increased 1.8-fold (0.182 to 0.329 per 10).In conclusion, anorectal melanomas, and especially, esophageal melanomas remain rare malignancies. This is the first report where temporal trends in anorectal melanoma are following the increased incidence of cutaneous melanomas, but it is unclear whether immunohistochemical diagnostic practices have influenced this trend. As gastrointestinal melanomas represent melanocytic transformation in the absence of sunlight, their epidemiology may provide etiologic clues to alternative or systemic transformative factors also operant in cutaneous melanoma.

Genomic profiling identifies common HPV-associated chromosomal alterations in squamous cell carcinomas of cervix and head and neck

Background

It is well known that a persistent infection with high-risk human papillomavirus (hrHPV) is causally involved in the development of squamous cell carcinomas of the uterine cervix (CxSCCs) and a subset of SCCs of the head and neck (HNSCCs). The latter differ from hrHPV-negative HNSCCs at the clinical and molecular level.

Methods

To determine whether hrHPV-associated SCCs arising from different organs have specific chromosomal alterations in common, we compared genome-wide chromosomal profiles of 10 CxSCCs (all hrHPV-positive) with 12 hrHPV-positive HNSCCs and 30 hrHPV-negative HNSCCs. Potential organ-specific alterations and alterations shared by SCCs in general were investigated as well.

Results

Unsupervised hierarchical clustering resulted in one mainly hrHPV-positive and one mainly hrHPV-negative cluster. Interestingly, loss at 13q and gain at 20q were frequent in HPV-positive carcinomas of both origins, but uncommon in hrHPV-negative HNSCCs, indicating that these alterations are associated with hrHPV-mediated carcinogenesis. Within the group of hrHPV-positive carcinomas, HNSCCs more frequently showed gains of multiple regions at 8q whereas CxSCCs more often showed loss at 17p. Finally, gains at 3q24-29 and losses at 11q22.3-25 were frequent (>50%) in all sample groups.

Conclusion

In this study hrHPV-specific, organ-specific, and pan-SCC chromosomal alterations were identified. The existence of hrHPV-specific alterations in SCCs of different anatomical origin, suggests that these alterations are crucial for hrHPV-mediated carcinogenesis.

Molecular mechanisms of cervical carcinogenesis by high-risk human papillomaviruses: novel functions of E6 and E7 oncoproteins

Over the last two decades, since the initial discovery of human papillomavirus (HPV) type 16 and 18 DNAs in cervical cancers by Dr. Harald zur Hausen (winner of the Nobel Prize in Physiology or Medicine, 2008), the HPVs have been well characterised as causative agents for cervical cancer. Viral DNA from a specific group of HPVs can be detected in at least 90% of all cervical cancers and two viral genes, E6 and E7, are invariably expressed in HPV-positive cervical cancer cells. Their gene products are known to inactivate the major tumour suppressors, p53 and retinoblastoma protein (pRB), respectively. In addition, one function of E6 is to activate telomerase, and E6 and E7 cooperate to effectively immortalise human primary epithelial cells. Though expression of E6 and E7 is itself not sufficient for cancer development, it seems to be either directly or indirectly involved in every stage of multi-step carcinogenesis. Epidemiological and biological studies suggest the potential efficacy of prophylactic vaccines to prevent genital HPV infection as an anti-cancer strategy. However, given the widespread nature of HPV infection and unresolved issues about the duration and type specificity of the currently available HPV vaccines, it is crucial that molecular details of the natural history of HPV infection as well as the biological activities of the viral oncoproteins be elucidated in order to provide the basis for development of new therapeutic strategies against HPV-associated malignancies. This review highlights novel functions of E6 and E7 as well as the molecular mechanisms of HPV-induced carcinogenesis.

Histological characteristics of human papilloma-virus-positive and -negative invasive and in situ squamous cell tumours of the penis

A high prevalence of cervical cancer associated high-risk types of human papillomavirus (hrHPV) has been demonstrated in premalignant and invasive squamous cell lesions of the penis, but large studies correlating histological characteristics with HPV status are few in number. Tumour tissues from 145 patients with invasive (n = 116) or in situ (n = 29) penile squamous cell carcinoma were subjected to systematic histological evaluation and were PCR-tested for 14 hrHPV types and 23 low-risk HPV types. Around half (52%) of invasive and nine-tenths (90%) of in situ lesions were positive for an hrHPV type, of which HPV 16 was by far the predominant type (91% of hrHPV-positive lesions). In relation to histological characteristics, hrHPV positivity was statistically significantly more common in high-grade tumours, lesions dominated by small tumour cells, lesions with a high number of multinucleated cells and mitoses, and lesions with a small amount of parakeratosis. In conclusion, about half of invasive penile squamous carcinomas in this study were hrHPV-positive, most notably to HPV 16, and probably arose through in situ lesions whereas the other half of invasive penile lesions appeared to be unrelated to hrHPV. A number of histological characteristics differed significantly between hrHPV-positive and -negative invasive penile carcinomas.

Tumor Morphology and Immunohistochemical Expression of Estrogen Receptor, Progesterone Receptor, p53, and Ki67 in Urogenital Carcinomas of California Sea Lions (Zalophus californianus)

Metastatic carcinoma of urogenital origin is a common cause of mortality in free-ranging California sea lions (Zalophus californianus). The etiology of this cancer is likely multifactorial, with viral infection, genetic factors, and exposure to environmental organochlorine contaminants possible contributing factors. In this study, expression of estrogen receptor α (ER α), progesterone receptor (PR), p53, and Ki67 were evaluated by immunohistochemistry in 12 sea lions with metastatic carcinoma, genital epithelial dysplasia, and intraepithelial neoplasia; 4 with genital epithelial dysplasia and intraepithelial neoplasia without metastases; and 6 control animals. Dysplastic and neoplastic lesions were identified in multiple areas of the cervix, vagina, penis, prepuce, and urethra in affected animals, suggesting multicentric development. Lesions were graded according to degree of epithelial dysplasia and infiltration and lesions of different grades were evaluated separately. Estrogen receptor expression was lower in intraepithelial lesions compared with normal genital epithelium, and expression in metastatic lesions was completely absent. There was progesterone receptor expression in neoplastic cells in intraepithelial lesions of all grades and in metastases, with no significant difference between lesion grades or between control and affected epithelium. Ki67 index and p53 expression increased with lesion grade and were higher in lesions than normal epithelium. Metastatic tumors exhibited highly variable morphology; however, proliferation index, ER α, PR, and p53 expression were similar in tumors with different patterns of growth. These results suggest that endogenous hormones, environmental contaminants that interact with steroid hormone receptors, and alterations in p53 may play a role in urogenital carcinogenesis in California sea lions.

Epigenetic alterations in cervical carcinogenesis

During cervical carcinogenesis, the major etiologic factor, the persistent oncogenic HPV infection itself is not sufficient to immortalize and transform the epithelial host cells. Together with further genetic and epigenetic alterations disrupting the cell cycle control, the host cell acquires immortal phenotype and progresses further to an overt malignant and invasive phenotype. Here, we discuss how cancer-associated epigenetic alterations can affect the expression of papillomaviral as well as host genes in relation to stages representing the multistep process of carcinogenesis. Biomarker roles in clinical diagnosis and prognosis might be assigned to the epigenetic pattern of the involved genes.

Comparisons of high-risk cervical HPV infections in Caribbean and US populations

Background

Disparities in cervical cancer incidence and mortality rates exist among women of African ancestry (African-American, African-Caribbean and African). Persistent cervical infection with Human papillomavirus (HPV) is associated with cervical dysplasia and if untreated, could potentially progress to invasive cervical cancer. Very few studies have been conducted to examine the true prevalence of HPV infection in this population. Comparisons of cervical HPV infection and the type-specific distribution of HPV were performed between cancer-free Caribbean and US women.

Results

The Caribbean population consisted of 212 women from Tobago and 99 women from Jamaica. The US population tested, consisted of 82 women from Pittsburgh. The majority of the US subjects was Caucasian, 74% (61/82) while 12% (10/82) and 13% (11/82) were African-American or other ethnic groups, respectively. The age-adjusted prevalence of any HPV infection among women from Tobago was 35%, while for Jamaica, it was 81% (p < 0.0001). The age-adjusted prevalence of HPV infection for Caribbean subjects was not statistically significantly different from the US (any HPV: 47% vs. 39%, p > 0.1; high-risk HPVs: 27% vs. 25%, p > 0.1); no difference was observed between US-Blacks and Jamaicans (any HPV: 92% vs. 81%, p > 0.1; high-risk HPV: 50% vs. 53%, p > 0.1). However, US-Whites had a lower age-adjusted prevalence of HPV infections compared to Jamaican subjects (any HPV: 29% vs. 81%, p < 0.0001; high-risk HPV: 20% vs. 53%, p < 0.001). Subjects from Jamaica, Tobago, and US-Blacks had a higher proportion of high-risk HPV infections (Tobago: 20%, Jamaica: 58%, US-Blacks: 40%) compared to US-Whites (15%). Similar observations were made for the presence of infections with multiple high-risk HPV types (Tobago: 12%, Jamaica: 43%, US-Blacks: 30%, US-Whites: 8%). Although we observed similar prevalence of HPV16 infections among Caribbean and US-White women, there was a distinct distribution of high-risk HPV types when comparisons were made between the ethnic groups.

Conclusion

The higher prevalence of cervical HPV infections and multiple high-risk infections in Caribbean and US-Black women may contribute to the high incidence and prevalence of cervical cancer in these populations. Evaluation of a larger sample size is currently ongoing to confirm the distinct distribution of HPV types between ethnic groups.

Infectious agents and colorectal cancer: a review of Helicobacter pylori, Streptococcus bovis, JC virus, and human papillomavirus

Based on the high volume of bacteria and viruses that the intestine is exposed to and the importance of infectious agents in some gastrointestinal and anogenital cancers, it is not surprising the many studies have evaluated the association between colorectal cancer and infectious agents. This review highlights investigations of four agents in relation to colorectal cancer. Helicobacter pylori, Streptococcus bovis, JC virus, and human papillomavirus have all been evaluated as possible etiologic agents for colorectal cancer. For each of these agents, a review of possible mechanisms for carcinogenesis and epidemiologic evidence is discussed, and future directions for research are proposed.

In silico analysis of protein neoplastic biomarkers for cervix and uterine cancer

Worldwide, cervical and uterine cancers are the most deadly cancers in women, with high prevalences, especially in developing countries. The Human Protein Atlas (HPA) portal was explored for proteins expressed in a tissue- or cervix and uterine cancer-specific manner. The group of proteins differentially expressed and with enhanced expression in the glandular and surface epithelial (squamous) cells retrieved from HPA were further explored using the Protein Information and Knowledge Extractor (PIKE) portal to compile biological information that is found in different databases, and repositories on the Internet. Thus, the lists of candidate proteins found in HPA, and PIKE portals may be used as a starting point for the discovery and validation of biomarkers for cervix and uterine cancer employing proteomics approaches as described in the present article.

Integrated genomic and transcriptional profiling identifies chromosomal loci with altered gene expression in cervical cancer

For a better understanding of the consequences of recurrent chromosomal alterations in cervical carcinomas, we integrated genome-wide chromosomal and transcriptional profiles of 10 squamous cell carcinomas (SCCs), 5 adenocarcinomas (AdCAs) and 6 normal controls. Previous genomic profiling showed that gains at chromosome arms 1q, 3q, and 20q as well as losses at 8q, 10q, 11q, and 13q were common in cervical carcinomas. Altered regions spanned multiple megabases, and the extent to which expression of genes located there is affected remains unclear. Expression analysis of these previously chromosomally profiled carcinomas yielded 83 genes with significantly differential expression between carcinomas and normal epithelium. Application of differential gene locus mapping (DIGMAP) analysis and the array CGH expression integration tool (ACE-it) identified hotspots within large chromosomal alterations in which gene expression was altered as well. Chromosomal gains of the long arms of chromosome 1, 3, and 20 resulted in increased expression of genes located at 1q32.1-32.2, 3q13.32-23, 3q26.32-27.3, and 20q11.21-13.33, whereas a chromosomal loss of 11q22.3-25 was related to decreased expression of genes located in this region. Overexpression of DTX3L, PIK3R4, ATP2C1, and SLC25A36, all located at 3q21.1-23 and identified by DIGMAP, ACE-it or both, was confirmed in an independent validation sample set consisting of 12 SCCs and 13 normal ectocervical samples. In conclusion, integrated chromosomal and transcriptional profiling identified chromosomal hotspots at 1q, 3q, 11q, and 20q with altered gene expression within large commonly altered chromosomal regions in cervical cancer.

Specific betapapillomaviruses associated with squamous cell carcinoma of the skin inhibit UVB-induced apoptosis of primary human keratinocytes

Epidemiological studies have shown an association between infections by specific betapapillomaviruses, such as human papillomavirus (HPV) types 5 and 8, and cutaneous squamous cell carcinoma (SCC). The role of betapapillomaviruses in the development of cutaneous SCC is, however, still enigmatic. The ability to inhibit UVB-induced apoptosis, as demonstrated for HPV5 in vitro, may be important in this respect, as survival of DNA-damaged and mutated cells increases the risk of transformation. The aim of this study was to assess whether inhibition of UVB-induced apoptosis is a general property of betapapillomaviruses and to identify apoptotic factors that are potentially involved in this process. Primary human keratinocytes transduced with E6 and E7 of selected betapapillomaviruses (HPV5, HPV8, HPV15, HPV20, HPV24 and HPV38) were characterized and subjected to UVB irradiation. HPV8- and HPV20-expressing keratinocytes in particular showed fewer signs of apoptosis, as demonstrated by lower levels of active caspase 3, less enzymic caspase activity and less DNA fragmentation. The observed inhibition of UVB-induced apoptosis was mediated by E6 and coincided with reduced steady-state expression of the pro-apoptotic protein Bax. In conclusion, E6 of HPV8 and HPV20 reduces the apoptotic responses upon UVB irradiation when expressed in primary human keratinocytes. Infections with HPV8 and HPV20 may therefore augment the carcinogenic effect of UV radiation and potentially contribute to oncogenic transformation of the skin.

Transforming growth factor beta1 promotes chromosomal instability in human papillomavirus 16 E6E7-infected cervical epithelial cells

Uterine cervical cancer, the second most frequently occurring cancer in women worldwide, is tightly associated with the expression of high-risk human papillomavirus [mainly human papillomavirus (HPV)-16 and HPV18] oncogenes E6 and E7 and characteristically exhibits chromosomal instability. However, the mechanisms underlying chromosomal instability in cervical cancer are still not fully understood. In this study, we observed that two of three human cervical epithelial cell lines expressing HPV16 E6E7 became immortalized without extensive chromosomal instability and crisis. The introduction of transforming growth factor (TGF)-beta1, a multiple functional cytokine/growth factor, in the culture medium induced crisis, which was associated with massive chromosomal end-to-end fusions and other structural aberrations. The distributions of structural aberrations on individual chromosomes were significantly correlated with the profiles of telomere signal-free ends. The immortalized cells that emerged from the TGF-beta1-induced crisis showed multiple clonal structural aberrations that were not observed in cells without TGF-beta1 treatment. Overexpression of the catalytic subunit of telomerase (hTERT) abolished the effects of TGF-beta1 on chromosomal instability. Interestingly, another HPV16 E6E7-expressing cervical cell line that experienced crisis and telomere dysfunction under ordinary culture condition had a higher level of autocrine TGF-beta1 production than the other two crisis-free immortalized cell lines. Blocking the TGF-beta1 pathway by an inhibitor of TGF-beta1 receptor type I prevented the crisis and telomere-mediated chromosomal instability. In addition, more dramatic telomere shortening was observed in cervical intraepithelial neoplasias having higher expression of TGF-beta1 in vivo. These results together suggest an important role of TGF-beta1 in the early process of cervical carcinogenesis.

Human papillomavirus detected in female breast carcinomas in Japan

To investigate the aetiological role of human papillomavirus (HPV) in breast cancer, we examined the presence, genotype, viral load, and physical status of HPV in 124 Japanese female patients with breast carcinoma. Human papillomavirus presence was examined by PCR using SPF10 primers, and primer sets targeting the E6 region of HPV-16, -18, and -33. The INNO-LiPA HPV genotyping kit was used to determine genotype. Human papillomavirus DNA was detected in 26 (21%) breast carcinomas. The most frequently detected HPV genotype was HPV-16 (92%), followed by HPV-6 (46%), HPV-18 (12%), and HPV-33 (4%). In 11 normal epithelium specimens adjacent to 11 HPV-16-positive carcinomas, 7 were HPV-16-positive. However, none of the normal breast tissue specimens adjacent to HPV-negative breast carcinomas were HPV-positive. The real-time PCR analysis suggested the presence of integrated form of viral DNA in all HPV-16-positive samples, and estimated viral load was low with a geometric mean of 5.4 copies per 10(4) cells. In conclusion, although HPV DNA was detected in 26 (21%) breast carcinomas and, in all HPV-16-positive cases, the HPV genome was considered integrated into the host genome, their low viral loads suggest it is unlikely that integrated HPV is aetiologically involved in the development of Japanese breast carcinomas that we examined.

Human papillomavirus infection in oral verrucous carcinoma: genotyping analysis and inverse correlation with p53 expression

OBJECTIVE

Verrucous carcinoma (VC) is a rare subtype of squamous cell carcinoma, occurring mostly in oral mucosa. To clarify the role of human papillomavirus (HPV) in VC tumorigenesis, we investigated localization and genotypes of HPV and p53 expression in oral VC.

METHODS

We studied paraffin-embedded specimens of 23 VCs and 10 control non-neoplastic lesions in oral mucosa. To investigate HPV infection, HPV genotypes and p53 expression, we respectively employed in situ hybridization (ISH), sequence analysis following short PCR fragment-PCR assay and immunohistochemistry.

RESULTS

Of the 23 VC specimens, 11 (48%) had HPV-DNA (detectable by PCR), and 6 (26%) had intranuclear HPV in the upper portion of the squamous epithelium (detectable by ISH). Nine of the 11 PCR-positive specimens showed multiple infections with low- and high-risk HPVs. No HPV-16 infection was detected. Although HPV-6 and HPV-18 were frequently detected by PCR, no HPV could be found in control specimens by ISH. p53 expression was inversely correlated with HPV infection.

CONCLUSION

Thus, multiple infections with low- and high-risk HPVs and their rapid replication during hyperkeratinization may participate in the histogenesis of oral VC. Oral VC tumorigenesis may involve the inactivation of p53, which is associated with HPV infection.

Gene expression profiling to identify markers associated with deregulated hTERT in HPV-transformed keratinocytes and cervical cancer

Although high-risk human papillomavirus (HPV) infection plays a major role in the development of cervical cancer, additive oncogenic events are involved as well. One key event involves increased activity of telomerase resulting from a deregulated expression of its catalytic subunit hTERT. Our previous microcell-mediated chromosome transfer studies revealed that introduction of human chromosome 6 in the HPV16-immortalized keratinocyte cell line FK16A and in the HPV16-containing cervical cancer cell line SiHa induced growth arrest, resulting from a repression of hTERT mRNA expression and telomerase activity. Here, this model was used to analyze expression profiles associated with hTERT deregulation in HPV-transformed cells. Microarray expression analysis of 12 FK16A/chromosome 6 hybrids, 4 of which were negative for endogenous hTERT and 8 of which were positive for endogenous hTERT, resulted in the identification of 164 differentially expressed genes. Differential expression of a selection of 5 genes was verified by real-time RT-PCR. Of these 164 genes, 32 were also differentially expressed in other HPV transformed cells with deregulated hTERT. For 2 of these genes, encoding AQP3 and MGP, altered expression in hTERT positive cervical carcinomas was confirmed by real-time RT-PCR and immunohistochemistry, respectively. Moreover, increased MGP protein expression was significantly more frequent in high-grade cervical premalignant lesions with elevated hTERT mRNA expression compared to those without. In summary, we identified 32 candidate biomarkers for deregulated hTERT mRNA expression, which may enable the identification of cervical premalignant lesions that are at highest risk to progress to invasive cancer.

Deletion of the PDZ motif of HPV16 E6 preventing immortalization and anchorage-independent growth in human tonsil epithelial cells

BACKGROUND

Human papillomavirus 16 (HPV16) has been associated with head and neck squamous cell carcinoma (HNSCC) in up to 60% of sampled specimens.

METHODS

To understand better the viral genes required to transform human tonsil epithelial cells (HTEC), we isolated HTEC's and transduced them with retroviral vectors containing HPV16 E6 and E7.

RESULTS

Immortalization and anchorage-independent growth of HTEC's only occurred with expression of E6 and E7 with resultant degradation of p53. However, cells expressing E6 lacking the PSD-95/disc-large/Zo-1 (PDZ) motif did not immortalize or grow anchorage independent. Telomerase activity and degradation of p53 were similar for wild-type and mutant E6.

CONCLUSION

The mechanism of oncogenic transformation by E6 in HTEC's is dependent on the PDZ binding motif. Identification of pathways affected by the interaction of E6 and PDZ domain containing proteins will further our understanding of how HPV causes HNSCC and will provide potential therapeutic targets.

Anal intraepithelial neoplasia and other neoplastic precursor lesions of the anal canal and perianal region

Anal cancer is rare and this helps to explain why anal pre-neoplastic conditions are poorly understood, especially with regard to their natural history and management. Anal intraepithelial neoplasia is closely linked to human papillomavirus infection and is particularly common in homosexuals and in immunosuppressed patients, especially those with HIV/AIDS. The high regression rates of low-grade anal intraepithelial neoplasia may simply reflect inconsistent pathologic reporting. Higher grades of anal intraepithelial neoplasia may remain static for long periods of time in immunocompetent patients, but those with HIV/AIDS show early and rapid malignant transformation. In general, most anal pre-neoplastic conditions are best diagnosed by biopsy and treated by surgical excision, although local recurrence is a problem. In anal Paget's disease, it is important to ascertain, at the time of diagnosis, whether it is due to a primary in-situ apocrine-type of neoplasia of the anus or if the disease is secondary to an invasive primary carcinoma of the rectum.

Critical roles for non-pRb targets of human papillomavirus type 16 E7 in cervical carcinogenesis

High-risk human papillomaviruses (HPV) encode two oncogenes, E6 and E7, expressed in nearly all cervical cancers. In vivo, HPV-16 E7 has been shown to induce multiple phenotypes in the context of transgenic mice, including cervical cancer. E7 is a multifunctional protein known best for its ability to inactivate the tumor suppressor pRb. To determine the importance of pRb inactivation by E7 in cervical cancer, we pursued studies with genetically engineered mice. E7 expression in estrogen-treated murine cervix induced dysplasia and invasive cancers as reported previously, but targeted Rb inactivation in cervical epithelium was not sufficient to induce any cervical dysplasia or neoplasia. Furthermore, E7 induced cervical cancer formation even when the E7-pRb interaction was disrupted by the use of a knock-in mouse carrying an E7-resistant mutant Rb allele. pRb inactivation was necessary but not sufficient for E7 to overcome differentiation-induced or DNA damage-induced cell cycle arrest, and expression patterns of the E2F-responsive genes Mcm7 and cyclin E indicate that other E2F regulators besides pRb are important targets of E7. Together, these data indicate that non-pRb targets of E7 play critical roles in cervical carcinogenesis.

Sequential gene promoter methylation during HPV-induced cervical carcinogenesis

We aimed to link DNA methylation events occurring in cervical carcinomas to distinct stages of HPV-induced transformation. Methylation specific-multiplex ligation-dependent probe amplification (MS-MLPA) analysis of cervical carcinomas revealed promoter methylation of 12 out of 29 tumour suppressor genes analysed, with MGMT being most frequently methylated (92%). Subsequently, consecutive stages of HPV16/18-transfected keratinocytes (n=11), ranging from pre-immortal to anchorage-independent phenotypes, were analysed by MS-MLPA. Whereas no methylation was evident in pre-immortal cells, progression to anchorage independence was associated with an accumulation of frequent methylation events involving five genes, all of which were also methylated in cervical carcinomas. TP73 and ESR1 methylation became manifest in early immortal cells followed by RARbeta and DAPK1 methylation in late immortal passages. Complementary methylation of MGMT was related to anchorage independence. Analysis of nine cervical cancer cell lines, representing the tumorigenic phenotype, revealed in addition to these five genes frequent methylation of CADM1, CDH13 and CHFR. In conclusion, eight recurrent methylation events in cervical carcinomas could be assigned to different stages of HPV-induced transformation. Hence, our in vitro model system provides a valuable tool to further functionally address the epigenetic alterations that are common in cervical carcinomas.

Basic mechanisms of high-risk human papillomavirus-induced carcinogenesis: roles of E6 and E7 proteins

Human papillomaviruses (HPV) are believed to be the primary causal agents for development of pre-neoplastic and malignant lesions of the uterine cervix, and high-risk types such as type 16 and 18 are associated with more than 90% of all cervical carcinomas. The E6 and E7 genes of HPV are thought to play causative roles, since E6 promotes the degradation of p53 through its interaction with E6AP, an E3 ubiquitin ligase, whereas E7 binds to the retinoblastoma protein (pRb) and disrupts its complex formation with E2F transcription factors. Although prophylactic vaccines have become available, it is still necessary to clarify the mechanisms of HPV-induced carcinogenesis because of the widespread nature of HPV infection. Approximately 493,000 new cases of cervical cancer are diagnosed each year with approximately 274,000 mortalities due to invasive cervical cancer. In the present article, the mechanisms of HPV16 E6- and E7-induced multistep carcinogenesis and recently identified functions of these onco-proteins are reviewed.

Impairment of the telomere/telomerase system and genomic instability are associated with keratinocyte immortalization induced by the skin human papillomavirus type 38

The skin human papillomavirus (HPV) types belonging to the genus beta of the HPV phylogenetic tree appear to be associated with nonmelanoma skin cancer. We previously showed that the beta HPV type 38 E6 and E7 oncoproteins are able to inactivate the tumor suppressors p53 and retinoblastoma. Here, both viral proteins were expressed in primary human skin keratinocytes in order to study their effects on the telomere/telomerase system. We show that immortalization of skin keratinocytes induced by HPV38 E6/E7 is associated with hTERT gene overexpression. This event is, in part, explained by the accumulation of the p53-related protein, DeltaNp73. Despite elevated levels of hTERT mRNA, the telomerase activity detected in HPV38 E6/E7 keratinocytes was lower than that observed in HPV16 E6/E7 keratinocytes. The low telomerase activation in highly proliferative HPV38 E6/E7 keratinocytes resulted in the presence of extremely short and unstable telomeres. In addition, we observed anaphase bridges, mitotic multipolarity, and dramatic genomic aberrations. Interestingly, the ectopic expression of hTERT prevents both telomere erosion and genomic instability. Thus, we showed that in HPV38 E6/E7 keratinocytes characterized by unscheduled proliferation, suboptimal activation of telomerase and subsequent extensive telomere shortening result in genomic instability facilitating cellular immortalization.

Physical status of multiple human papillomavirus genotypes in flow-sorted cervical cancer cells

Multiple human papilloma virus (HPV) infections have been detected in cervical cancer. To investigate the significance of multiple HPV infections, we studied their prevalence in cancer samples from a low-risk (Dutch) and a high-risk (Surinamese) population and the correlation of HPV infection with tumor cell aneuploidy. SPF(10) LiPA was used for HPV detection in formalin-fixed cervical carcinoma samples from 96 Dutch and 95 Surinamese patients. Samples with HPV type 16 or 18 infections were sorted by flow cytometry, and fluorescence in situ hybridization was performed on the diploid and aneuploid subpopulations to detect HPV 16 and 18 genotypes simultaneously. Multiple HPV infections were present in 11 of 80 (13.8%) Dutch and 17 of 77 (22.1%) Surinamese carcinomas. Three cases had an HPV 16 and HPV 18 coinfection: in two cases, integrated HPV copies of HPV 16 or 18 were detected in the aneuploid fraction, and in one case both HPV 16 and 18 were present solely as episomes. Based on our findings, multiple HPV infections are present in cervical cancer samples from both high- and low-risk populations. Furthermore, multiple HPV types can be present in an episomal state in both diploid and aneuploid tumor cells, but integrated HPV genomes are detectable only in the aneuploid tumor cell subpopulations.

Translational mini-review series on vaccines: Monitoring of human papillomavirus vaccination

Persistent infection with oncogenic human papillomavirus (HPV) is a necessary cause of cervical cancer. Moreover, HPV type 16 (and to a lesser degree HPV type 18) is linked with more rare cancers, namely cancer of the vulva, vagina, penis, anus, oropharynx and larynx. Effective prophylactic vaccines have been developed. In this review, we briefly address immunological aspects of HPV infection and the results of HPV vaccination trials. Internationally standardized monitoring and evaluation of prophylactic HPV vaccination programmes will be essential for arriving at the most (cost-)effective strategies for cancer control.

A cross-sectional survey to assess community attitudes to introduction of Human Papillomavirus vaccine

OBJECTIVE

A vaccine to prevent human papilloma virus (HPV) infection has been licensed recently in the United States of America and Australia. The aim of this study was to assess community attitudes to the introduction of HPV vaccine in the State of South Australia.

METHODS

A cross-sectional survey was conducted by computer-aided telephone interviews in February 2006. The survey assessed adult and parental attitudes to the introduction of HPV vaccine to provide protection against a sexually transmitted disease caused by HPV and against cervical cancer. Two thousand interviews were conducted in metropolitan and rural households.

RESULTS

Two per cent of respondents knew that persistent HPV infection caused cervical cancer and a further 7% were aware that the cause was viral. The majority of adults interviewed (83%) considered that both men and women should receive HPV vaccine and 77% of parents agreed that they would have their child/children immunised. Parents were mainly concerned about possible side effects of the vaccine (66%), with only 0.2% being concerned about discussing a sexually transmitted disease with their children and 5% being concerned that use of the vaccine may lead to promiscuity.

IMPLICATIONS

Our findings suggest that public health education campaigns for HPV vaccination will find a majority of parents receptive to their children being vaccinated, but attention must be paid to appropriate explanation about HPV infection as the cause of cervical cancer and education about the safety of the HPV vaccine.

[Human papilloma virus-induced disease in HIV-positive patients]

Since the introduction of highly active antiretroviral therapy (HAART), opportunistic infections by bacteria and fungi have been reduced in human immunodeficiency virus (HIV)-positive patients. However, diseases caused by human papilloma virus (HPV) have become more frequent despite HAART. There is an increased incidence of anal and cervical carcinomas, their precancerous lesions such as anal/cervical intraepithelial neoplasia, and condylomas and oral warts. In order to prevent anal carcinomas, HIV-positive patients should receive proctoscopic examinations regularly. The examination should include anoscopy and smears for cytology and HPV polymerase chain reaction.

Review of current knowledge on HPV vaccination: An Appendix to the European Guidelines for Quality Assurance in Cervical Cancer Screening

The recognition of a strong etiological relationship between infection with high-risk human papillomavirusses and cervical cancer has prompted research to develop and evaluate prophylactic and therapeutic vaccines. One prophylactic quadrivalent vaccine using L1 virus-like particles (VLP) of HPV 6, 11, 16 and 18 is available on the European market since the end of 2006 and it is expected that a second bivalent vaccine containing VLPs of HPV16 and HPV18 will become available in 2007. Each year, HPV16 and HPV18 cause approximately 43,000 cases of cervical cancer in the European continent. Results from the phase-IIb and III trials published thus far indicate that the L1 VLP HPV vaccine is safe and well-tolerated. It offers HPV-naive women a very high level of protection against HPV persistent infection and cervical intra-epithelial lesions associated with the types included in the vaccine. HPV vaccination should be offered to girls before onset of sexual activity. While prophylactic vaccination is likely to provide important future health gains, cervical screening will need to be continued for the whole generation of women that is already infected with the HPV types included in the vaccine. Phase IV studies are needed to demonstrate protection against cervical cancer and to verify duration of protection, occurrence of replacement by non-vaccine types and to define future policies for screening of vaccinated cohorts. The European Guidelines on Quality Assurance for Cervical Cancer Screening provides guidance for secondary prevention by detection and management of precursors lesions of the cervix. The purpose of the appendix on vaccination is to present current knowledge. Developing guidelines for future use of HPV vaccines in Europe, is the object of a new grant offered by the European Commission.

Epidermodysplasia Verruciformis and Cutaneous Human Papillomavirus DNA, but Not Genital Human Papillomavirus DNAs, Are Frequently Detected in Vulvar and Vaginal Melanoma

Vulvovaginal melanomas are rare and their etiology is unknown. Genital mucosal human papillomavirus (HPV) 16 has been identified in both cutaneous and mucosal melanoma, suggesting that it might play a role in the pathogenesis or progression of melanoma. In this study, we investigated the prevalence of HPV DNA by using a broad spectrum of degenerate and type-specific primers for genital-mucosal, epidermodysplasia verruciformis-associated (EV), and cutaneous HPV types in 6 vulvar and 3 vaginal melanomas. The patients were mostly postmenopausal women (8/9), had a mean age of 67 years (range, 44-85 years), and had mucosal lentiginous (7) or nodular (2) melanomas. In the adjacent skin/mucosa, mucosal melanosis was found in 5, lichen sclerosus or a lichenoid mucositis in 4, and blue nevi in 2 women. With nested polymerase chain reaction techniques followed by direct sequencing, HPV DNA was identified in 6 of 9 (67%) melanomas; these were either cutaneous (HPV 3) (4/9) or epidermodysplasia verruciformis-associated types (HPV 38, Z95969, AJ00151) (4/9). Epidermodysplasia verruciformis-associated HPV (type 15) was found solely in 1/10 (10%) normal vulvar controls. Genital-mucosal HPV types were not detected either by degenerate nested polymerase chain reaction or type-specific probes for HPV 16. We propose that the above findings are not coincidental but may represent a molecular record of HPV involvement in pathogenesis or progression of melanoma, which is consistent with the strong but poorly defined association of cutaneous HPV types with nonmelanoma skin cancers. The theory that HPV may act as a cofactor in melanoma development deserves further clinical and experimental investigations.

Involvement of tumor suppressor in lung cancer 1 gene expression in cervical carcinogenesis

Tumor suppressor in lung cancer 1 (TSLC1) is a tumor suppressor gene in non-small cell lung cancer, and loss of TSLC1 gene expression has been observed in a number of epithelial carcinomas and cancer-derived cell lines. We analyzed TSLC1 gene expression by real-time reverse transcription-polymerase chain reaction in 39 invasive cervical carcinomas, 34 cervical intraepithelial neoplasia (CIN) IIIs, 35 CIN IIs, 32 CIN I, 36 inflammation cervical tissues, and 30 normal cervix samples. Loss of TSLC1 gene expression was observed in 30 of 39 (77%) cervical carcinomas, 25 of 34 (73%) CIN IIIs, 9 of 35 (26%) CIN IIs, and 7 of 32 (22%) CIN Is but was not found in inflammation and normal cervix samples. Compared to normal cervical tissue, loss of TSLC1 gene was significantly high in CIN IIIs and cervical cancer (P = 0.00). Moreover, loss of TSLC1 gene expression is observed at a significantly higher frequency in CIN IIIs and cervical cancers than in CIN IIs (P < 0.05). The results show that loss of TSLC1 gene expression is an early event in cervical carcinogenesis and often accompanies invasive cervical cancers.

Bmi-1 cooperates with human papillomavirus type 16 E6 to immortalize normal human oral keratinocytes

Bmi-1 is a member of the polycomb group (PcG) transcription repressors and is implicated in human carcinogenesis. In normal human oral keratinocytes (NHOK), we found that exogenous Bmi-1 expression significantly extended the replicative life span without causing cellular immortalization. Immortalization of NHOK occurs only in combination with human papillomavirus type 16 E6 (HPV-16 E6) but not with E7. During immortalization of NHOK by sequential expression of exogenous Bmi-1 and E6, telomerase activation was observed only after the cells had overcome crisis. Genetic analysis with E6 deletion mutants revealed that the intact second zinc finger domain (amino acids 118-122) was necessary for its cooperative effects with Bmi-1 in the immortalization process. Using these mutants, we found that the increased telomerase activity was closely associated with cell immortalization by Bmi-1 and E6, whereas p53 degradation was not. Using microarray analysis, we identified genes that are immortalization-specific and may participate in the process of NHOK immortalization by Bmi-1 and HPV-16 E6. Our results provide new information on the roles of Bmi-1 and HPV-16 E6 in the multi-step process of oral epithelial carcinogenesis.

Evaluation of the SPF10-INNO LiPA human papillomavirus (HPV) genotyping test and the roche linear array HPV genotyping test

The need for accurate genotyping of human papillomavirus (HPV) infections is becoming increasingly important, since (i) the oncogenic potential among the high-risk HPV genotypes varies in the pathogenesis of cervical cancer, (ii) monitoring multivalent HPV vaccines is essential to investigate the efficiency of the vaccines, and (iii) genotyping is crucial in epidemiologic studies evaluating HPV infections worldwide. Various genotyping assays have been developed to meet this demand. Comparison of different studies that use various HPV genotyping tests is possible only after a performance assessment of the different assays. In the present study, the SPF(10) LiPA version 1 and the recently launched Roche Linear Array HPV genotyping assays are compared. A total of 573 liquid-based cytology samples were tested for the presence of HPV by a DNA enzyme immunoassay; 210 were found to be positive for HPV DNA and were evaluated using both genotyping assays (163 with normal cytology, 22 with atypical squamous cells of undetermined significance, 20 with mild/moderate dysplasia, and 5 with severe dysplasia). Comparison analysis was limited to the HPV genotype probes common to both assays. Of the 160 samples used for comparison analysis, 129 (80.6%) showed absolute agreement between the assays (concordant), 18 (11.2%) showed correspondence for some but not all genotypes detected on both strips (compatible), and the remaining 13 (8.2%) samples did not show any similarity between the tests (discordant). The overall intertest comparison agreement for all individually detectable genotypes was considered very good (kappa value, 0.79). The genotyping assays were therefore highly comparable and reproducible.

The prevalence of human papillomavirus genotypes in penile cancers from northern Thailand

The highest frequency of penile cancer occurs in Asia, Africa, and Latin America, and there have been a few reports concerning the association of penile cancer with human papillomavirus (HPV) infection in these areas. The objective of this study was to determine the relation between penile cancer and the prevalence of HPV genotypes in northern Thailand. Eighty-eight specimens of penile tissue (65 malignant, 1 pre-malignant, and 22 benign cases) were examined to determine the association of HPV infection. An in situ hybridization (ISH) method was used to detect and localize HPV-DNA. Sensitive HPV polymerase chain reaction (PCR) procedure was used for detection of HPV-DNA, and DNA sequencing was used to identify the HPV genotype. HPV-DNA was detected in 53.8% and 81.5% of cases of penile cancer, using ISH and PCR, respectively. The high-risk HPV-16, most commonly associated with penile cancer in previous reports, was found in only one case in this study. The most prevalent genotype was the high-risk HPV-18, found in 55.4% of the cases (32.3% single and 23.1% multiple infection) followed by the low-risk HPV-6, found in 43.1% of the cases (24.6% single and 18.5% multiple infection). In this study, penile cancer was found to be highly correlated with HPV-DNA. Specifically, infection with both the low-risk HPV-6 and the high-risk HPV-18 is the characteristic prevalence of HPV genotypes in penile cancer in this area.

Increased gene copy numbers at chromosome 20q are frequent in both squamous cell carcinomas and adenocarcinomas of the cervix

Genome-wide microarray-based comparative genomic hybridization (array CGH) was used to identify common chromosomal alterations involved in cervical carcinogenesis as a first step towards the discovery of novel biomarkers. The genomic profiles of nine squamous cell carcinomas (SCCs) and seven adenocarcinomas (AdCAs), as well as four human papillomavirus (HPV)-immortalized keratinocyte cell lines, were assessed. On a genome-wide scale, SCCs showed significantly more gains than AdCAs. More specifically, there was a striking and highly significant difference between the two histological types for gain at 3q12.1-28, which was predominantly observed in SCC. Other frequent alterations included gains of 1q21.1-31.1 and 20q11.21-13.33, and losses of 11q22.3-25 and 13q14.3-21.33. Subsequent FISH analysis for hTR, located at 3q26, confirmed the presence of 3q gain in SCCs and HPV-immortalized cell lines. Fine mapping of chromosome 20q using multiplex ligation-dependent probe amplification (MLPA) showed copy number increases for a number of genes located at 20q11-q12, including DNMT3B and TOP1. For DNMT3B, this correlated with elevated mRNA expression in 79% of cases. In conclusion, the assessment of frequent genomic alterations resulted in the identification of potential novel biomarkers, which may ultimately enable a better risk stratification of high-risk (hr)-HPV-positive women.

Dynamic behavioural interpretation of cervical intraepithelial neoplasia with molecular biomarkers

The microscopic phenotype of cervical intraepithelial neoplasia (CIN) reflects a fine balance between factors that promote or reduce CIN development. A shortcoming of the current grading system is its reliance on static morphology and microscopic haematoxylin-eosin features of the epithelium alone. In reality, CIN is a dynamic process, and the epithelium may exhibit differing results over time. Functional biomarkers p16, Ki-67, p53, retinoblastoma protein cytokeratin (CK)14 and CK13, help in the assessment of an individual CIN's lesion's potential for progression and regression. The aggregate information provided by these biomarkers exceeds the value of the classic grading system. Consequently, many more CINs that will either regress or progress can be accurately identified. These findings agree with known molecular interactions between HPV and the host. For accurate interpretation of a CIN, it is essential that these biomarkers be determined quantitatively and separately in the superficial, middle and deep layers of the epithelium. Such geography-specific epithelial evaluations of quantitative biomarkers emphasise the dynamic nature of a particular CIN lesion, thereby changing the art of static morphology grading into dynamic interpretation of the diseased tissue, with a strong prognostic effect.

Hydrogen peroxide producing lactobacilli in women with cervical neoplasia

PURPOSE

It is well known that human papillomavirus (HPV) is the main cause of cervical neoplasia, and hydrogen peroxide-producing lactobacilli are the most important microorganisms for maintaining the balance of the vaginal ecosystem. The purpose of our study was to investigate the relationship of hydrogen peroxide-producing lactobacilli, cervical neoplasia and high-risk HPV.

MATERIALS AND METHODS

We enrolled 1138 women with abnormal cervical smears or cervicograms who were referred to the department of Obstetrics and Gynecology at Chonnam National University Medical School. In all of them, 1,138 vaginal swabs were collected for the qualitative assay of hydrogen peroxide producing lactobacilli and 150 cervical swabs were used for the HPV hybrid capture II test without regard to the subjects' pregnancy status. In the non-pregnant women, 880 cervical biopsies and/or loop electrosurgical excision procedures were performed for making the histological diagnosis.

RESULTS

There was no significant difference not only between the distribution of H(2)O(2) producing lactobacilli and the cervical histology, but also between the distribution of H(2)O(2) producing lactobacilli and the positivity for high-risk HPV.

CONCLUSIONS

Both cervical neoplasia and high-risk HPV may not be influenced by the existence of hydrogen peroxide producing lactobacilli in the vagina.

Human Papillomaviruses and Genital Disease

Human papillomavirus (HPV) infection is causally related to several benign and malignant diseases of the anogenital tract. In this article the authors detail the epidemiology, methods of transmission and risk factors, pathogenesis, and oncogenesis of HPV, and describe clinical manifestations and current treatments. Special attention is given to condyloma acuminatum and non-cervical anogenital intraepithelial neoplasia. The authors conclude with the latest information on prophylactic vaccine development and prospects for future control of HPV-related disease.

HPV-mediated cervical carcinogenesis: concepts and clinical implications

Persistent infection with a high-risk human papillomavirus (hrHPV) is generally accepted as a necessary cause of cervical cancer. However, cervical cancer is a rare complication of an hrHPV infection since most such infections are transient, not even giving rise to cervical lesions. On average, it takes 12-15 years before a persistent hrHPV infection may ultimately, via consecutive premalignant stages (ie CIN lesions), lead to an overt cervical carcinoma. This argues that HPV-induced cervical carcinogenesis is multi-step in nature. In this review, the data from hrHPV-mediated in vitro transformation studies and those obtained from analysis of clinical specimens have been merged into a cervical cancer progression model. According to this model, a crucial decision maker in the early stages following infection involves individual susceptibility for certain HPV types depending on the genetic make-up of immune surveillance determinants. Once a CIN lesion has developed, altered transcriptional regulation of the viral E6/E7 oncogenes, resulting in genomic instability and distinguishing the process of cell transformation from a productive viral infection, probably provides the subsequent important step towards malignancy. The additional (epi)genetic alterations that subsequently accumulate in high-grade CIN lesions may result in overt malignancy via immortality and growth conditions that gradually become less sensitive to growth-modulating influences mediated by cytokines and cell-cell and cell-matrix adhesions. The potential implications of hrHPV testing and some other biomarkers deduced from this model for cervical screening and the clinical management of CIN disease are also discussed.

HPV testing in cervical screening

High-risk human papillomavirus (hrHPV) bearing cervical intraepithelial neoplasia (CIN) is considered, as the real precursor lesion of cervical cancer and persistence of an hrHPV infection is necessary for the progression to cervical cancer. This knowledge warrants the use of hrHPV testing as an adjunct to cervical cytology in population-based screening programmes and for monitoring therapy efficacy of high-grade CIN lesions. Replacement of cytology by hrHPV testing altogether is considered, but for this to be (cost-) effective, accurate information about the specificity of the hrHPV test is required. Additional test systems that can be used to stratify women with a positive hrHPV test are HPV genotyping, viral load analysis and hrHPV mRNA analysis. The need for HPV genotyping of cervical smears is illustrated by the increased risk for high-grade cervical lesions associated with HPV types 16 and 18. In particular, for women who have normal but persistently (>1 year) HPV18-positive smears, endocervical curettage is suggested (evidently considering the age and possible future pregnancies of the respective woman) because HPV18 is associated with glandular lesions in the cervix, which are difficult to detect by cytology.

The role of human papilloma virus infection in the etiology of oropharyngeal carcinoma

PURPOSE OF REVIEW

Evidence is growing that human papilloma virus is responsible for a subset of head and neck carcinomas. This review analyzes the history and current thinking regarding this relatively new etiologic agent of squamous cell carcinoma.

RECENT FINDINGS

Research over the past year has confirmed that human papilloma virus is associated with subset of head and neck squamous cell carcinoma, especially tumors arising from the tonsil. Human papilloma virus 16 is the most common strain found in these tumors. Most studies also indicate that patients with human papilloma virus infection are more likely to have a better prognosis, engage in riskier sexual behavior, and have a history of less tobacco and alcohol consumption than patients who have human papilloma virus-negative tumors. Not all studies confirm these findings, however, and human papilloma virus, even the high-risk strains (16, 18, and 33) are found in a certain percentage of healthy individuals.

SUMMARY

Human papilloma virus (especially strain 16) has been recognized as a probable etiologic agent for some head and neck squamous cell carcinomas. Most commonly, human papilloma virus is associated with tumors arising from the tonsillar epithelium. Because a definitive causal relationship is still to be identified, current research aims to delineate the specific mechanism whereby human papilloma virus produces squamous cell carcinoma. It is hoped that a vaccine may be produced in the near future that will serve as adjuvant therapy for patients with human papilloma virus-positive tumors.

Molecular diagnosis of human papillomavirus (HPV) infections

Human papillomaviruses (HPVs) comprise more than 100 genotypes. The mucosal types can be divided into high-risk and low-risk (LR) types depending on the associated disease risk. HPV infection is mainly diagnosed by molecular methods, since reliable serological tools are not available and culture of the virus is not possible. Accurate molecular diagnostic techniques that can be used to inform patient management and follow-up after treatment are now available for detection and identification of HPV. The diagnosis of HPV infections in patients at risk of disease in a clinical setting requires a different approach from that used for epidemiological studies, vaccination trials and natural history studies. This review describes the different molecular methods available for HPV detection and genotyping and their possible clinical utility.