Human papillomavirus infection of non-melanoma skin cancers in immunocompetent hosts

The Role of DNA Viruses in Human Cancer

This review discusses the possible involvement of infections-associated cancers in humans, with virus infections contributing 15% to 20% of total cancer cases in humans. DNA virus encoded proteins interact with host cellular signaling pathways and control proliferation, cell death and genomic integrity viral oncoproteins are known to bind cellular Deubiquitinates (DUBs) such as cyclindromatosis tumor suppressor, ubiquitin-specific proteases 7, 11, 15 and 20, and A-20 to improve their intracellular stability and cellular signaling pathways and finally transformation. Human papillomaviruses (cervical carcinoma, oral cancer and laryngeal cancer); human polyomaviruses (mesotheliomas, brain tumors); Epstein-Barr virus (B-cell lymphoproliferative diseases and nasopharyngeal carcinoma); Kaposi's Sarcoma Herpesvirus (Kaposi's Sarcoma and primary effusion lymphomas); hepatitis B (hepatocellular carcinoma (HCC)) cause up to 20% of malignancies around the world.

Current and Future Trends in Molecular Biomarkers for Diagnostic, Prognostic, and Predictive Purposes in Non-Melanoma Skin Cancer

Skin cancer represents the most common type of cancer among Caucasians and presents in two main forms: melanoma and non-melanoma skin cancer (NMSC). NMSC is an umbrella term, under which basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and Merkel cell carcinoma (MCC) are found along with the pre-neoplastic lesions, Bowen disease (BD) and actinic keratosis (AK). Due to the mild nature of the majority of NMSC cases, research regarding their biology has attracted much less attention. Nonetheless, NMSC can bear unfavorable characteristics for the patient, such as invasiveness, local recurrence and distant metastases. In addition, late diagnosis is relatively common for a number of cases of NMSC due to the inability to recognize such cases. Recognizing the need for clinically and economically efficient modes of diagnosis, staging, and prognosis, the present review discusses the main etiological and pathological features of NMSC as well as the new and promising molecular biomarkers available including telomere length (TL), telomerase activity (TA), CpG island methylation (CIM), histone methylation and acetylation, microRNAs (miRNAs), and micronuclei frequency (MNf). The evaluation of all these aspects is important for the correct management of NMSC; therefore, the current review aims to assist future studies interested in exploring the diagnostic and prognostic potential of molecular biomarkers for these entities.

Beta human papillomaviruses infection and skin carcinogenesis

During the last decade, the worldwide incidence of keratinocyte carcinomas (KC) has increased significantly. They are now the most common malignancy, representing approximately 30% of all cancers. The role of ultraviolet (UV) radiation as a major environmental risk factor for skin cancers is well recognized. The aim of this review is to analyse the current understanding of the nature of beta-human papillomavirus (HPV) and its association with KC and explore the implications for the management and prevention of these cancers. A comprehensive review of the literature on beta-HPV and its association with KC was undertaken, the results reported in the form of a narrative review. A subgroup of HPV that infects the mucosal epithelia of the genital tract has been firmly associated with carcinogenesis. In addition, some HPV types with cutaneous tropism have been proposed to cooperate with UV in the development of KC. The first evidence for this association was reported in 1922 in patients with epidermodysplasia verruciformis (EV). Since then, epidemiological studies have highlighted the higher risk of skin cancer in patients with EV and certain cutaneous HPV types, and in vitro studies have elucidated molecular mechanisms and transforming properties of beta-HPV. Furthermore, in vivo research conducted on transgenic mice models has shown the possible role of beta-HPV in cutaneous carcinogenesis as a co-factor with UV radiation and immunosuppression. There is good evidence supporting the role of beta-HPV in the oncogenesis of KC. The high prevalence of beta-HPV in human skin and the worldwide burden of KC makes the search for an effective vaccine relevant and worthwhile.

Association of Some High-Risk Mucosal Types of Human Papillomavirus with Cutaneous Squamous Cell Carcinoma in an Iranian Population

BACKGROUND & OBJECTIVE

Squamous cell carcinoma (SCC) is the second most common non-melanoma skin cancer that may be caused by Human papillomavirus (HPV), especially in immunosuppressed patients. However, the role of the mucosal types of HPV in SCC patients with normal immunity has not been extensively confirmed. The aim of this study was to investigate the association of some high-risk mucosal types of HPV with cutaneous SCC in an Iranian population.

METHODS

Sixty-five formalin-fixed, paraffin-embedded tissue specimens with a diagnosis of cutaneous SCC as the case group and sixty-five healthy skin specimens as the control group were included in our case-control study. Genomic DNA was extracted from tissue samples and then PCR was used for the detection of HPV genotypes by a commercial kit.

RESULTS

Our data revealed that 6 out of 65 SCC samples (9.2%) were infected by high-risk mucosal types of HPV whereas none of the 65 control samples were infected by the mentioned HPVs. Statistical analysis showed a significant association between these types of HPV infection and SCC risk in our studied population (P=0.028).

CONCLUSION

These findings suggested that some high-risk mucosal types of HPV are significant risk factors for cutaneous SCC.

Mucosal human papillomavirus detection and TP53 immunohistochemical expression in non-melanoma skin cancer in Tunisian patients

BACKGROUND

Several studies have reported the oncogenic role of human papillomavirus (HPV) in non-melanoma skin cancer (NMSC) carcinogenesis. Considering that HPV could affect tumor protein 53 (TP53) degradation via E6 oncoprotein, we evaluated the expression of TP53 according to HPV infection and E6 expression.

METHODS

Biopsy specimens from 79 NMSCs (28 squamous cell carcinomas, 21 keratoacanthomas and 30 basal cell carcinomas) were enrolled. Nested PCR was used to detect mucosal HPV (mHPV) DNA. Genotyping was performed by reverse line hybridization. Expression of TP53 and E6 was evaluated by immunohistochemistry.

RESULTS

mHPVs were detected in 34.2% (27/79) of NMSC, with 92.6% (25/27) of high-risk HPV (HR-HPV) types. HPV16-E6-positive expression was observed in all HPV16-positive samples. TP53 high expression was found in 51.4% (37/72) of specimens. In this group, 78.4% were HPV-negative (P = 0.014). TP53 expression was negative in 8/10 of HPV E6-positive specimens. Multivariate analysis showed that TP53 was associated with HPV infection independently of histopathologic type (P = 0.005).

CONCLUSION

This study showed a high prevalence of mHPV in NMSC. Active infections assessed by E6 expression are associated with loss of p53 function, highlighting the involvement of mHPV in NMSC carcinogenesis.

Genital basal cell carcinoma, a different pathogenesis from sun-exposed basal cell carcinoma? A case-control study of 30 cases

BACKGROUND

Genital basal cell carcinoma (BCC) accounts for <1% of all BCCs. We aimed to elucidate the pathogenesis of genital BCC.

METHODS

We retrospectively evaluated cases of pathologically diagnosed genital BCC between 1990 and 2016 in an Asian tertiary referral center. The control group was composed of consecutive cases, from 2016, of BCCs occurring in sun-exposed areas. Presence of human papillomavirus (HPV) was evaluated by polymerase chain reaction (PCR). Immunohistochemical p16 and p53 staining was performed and analyzed.

RESULTS

We found 33 genital BCCs (33/1837, 1.8%) over 26 years. The mean follow-up duration was 30.0 ± 33.2 months. Genital BCCs had a larger size (14.05 vs 8.92 mm, P = 0.014), more common presence of ulcers (61.3% vs 32.0%, P = 0.035), shorter epidermal p53 clone (0.33 vs 1.20 mm, P = 0.007), and high p53 expression levels. Most cases (29/30, 96.7%) showed negative or faint spotty p16 staining. Patient age, tumor depth, presence of pigment, or histology subtype did not differ significantly. Thirty genital BCCs were negative for HPV.

CONCLUSIONS

HPV infection is mostly likely not involved in genital BCC pathogenesis. A greater level of p53 expression in genital BCCs implicates pathways other than ultraviolet (UV)-specific p53 mutations in their pathogenesis.

Cutaneous squamous cell carcinoma and human papillomavirus: is there an association?

BACKGROUND

The role of human papillomavirus (HPV) in the induction and maintenance of cervical, anogenital, and some oropharyngeal carcinomas is well recognized, but its role in cutaneous squamous cell carcinoma (SCC) remains to be elucidated. HPV is thought to act as a possible cocarcinogen in the development of SCC.

OBJECTIVE

To review the literature assessing the correlation between and possible causation of HPV and cutaneous SCC in immunocompetent and immunocompromised populations.

METHODS

We reviewed HPV sampling and detection methods, epidemiologic studies examining HPV carriage in immunocompetent and immunosuppressed individuals, and evidence asserting an association between HPV and cutaneous SCC.

RESULTS

Although an abundant body of evidence points toward a link between HPV and cutaneous SCC, many studies indicate otherwise. Recent studies have focused on viral activity in addition to DNA presence.

CONCLUSION

The possibility exists that HPV may play a role in the induction but not maintenance of cutaneous SCC.

Large scale genotype comparison of human papillomavirus E2-host interaction networks provides new insights for e2 molecular functions

Human Papillomaviruses (HPV) cause widespread infections in humans, resulting in latent infections or diseases ranging from benign hyperplasia to cancers. HPV-induced pathologies result from complex interplays between viral proteins and the host proteome. Given the major public health concern due to HPV-associated cancers, most studies have focused on the early proteins expressed by HPV genotypes with high oncogenic potential (designated high-risk HPV or HR-HPV). To advance the global understanding of HPV pathogenesis, we mapped the virus/host interaction networks of the E2 regulatory protein from 12 genotypes representative of the range of HPV pathogenicity. Large-scale identification of E2-interaction partners was performed by yeast two-hybrid screenings of a HaCaT cDNA library. Based on a high-confidence scoring scheme, a subset of these partners was then validated for pair-wise interaction in mammalian cells with the whole range of the 12 E2 proteins, allowing a comparative interaction analysis. Hierarchical clustering of E2-host interaction profiles mostly recapitulated HPV phylogeny and provides clues to the involvement of E2 in HPV infection. A set of cellular proteins could thus be identified discriminating, among the mucosal HPV, E2 proteins of HR-HPV 16 or 18 from the non-oncogenic genital HPV. The study of the interaction networks revealed a preferential hijacking of highly connected cellular proteins and the targeting of several functional families. These include transcription regulation, regulation of apoptosis, RNA processing, ubiquitination and intracellular trafficking. The present work provides an overview of E2 biological functions across multiple HPV genotypes.

Over 100 types of human papillomaviruses are responsible for widespread infections in humans. They cause a wide range of pathologies, ranging from inapparent infections to benign lesions, hyperplasia or cancers. Such heterogeneity results from variable interplay among viral and host cell proteins. Aiming to identify specific features that distinguish different pathological genotypes, we mapped the virus-host interaction networks of the regulatory E2 proteins from a set of 12 genotypes representative of HPV diversity. The E2-host interaction profiles recapitulate HPV phylogeny, thus providing a valuable framework for understanding the role of E2 in HPV infection of different pathological traits. The E2 proteins tend to bind to highly connected cellular proteins, indicating a profound effect on the host cell. These interactions predominantly impact on a subset of cellular processes, like transcriptional regulation, apoptosis, RNA metabolism, ubiquitination or intracellular transport. This work improves the global understanding of HPV-associated pathologies, and provides a framework to select interactions that can be used as targets for the development of new therapeutics.

The channel physiology of the skin

During embryonic development, the skin, the largest organ of the human body, and nervous system are both derived from the neuroectoderm. Consequently, several key factors and mechanisms that influence and control central or peripheral nervous system activities are also present and hence involved in various regulatory mechanisms of the skin. Apparently, this is the case for the ion and non-ion selective channels as well. Therefore, in this review, we shall focus on delineating the regulatory roles of the channels in skin physiology and pathophysiology. First, we introduce key cutaneous functions and major characteristics of the channels in question. Then, we systematically detail the involvement of a multitude of channels in such skin processes (e.g. skin barrier formation, maintenance, and repair, immune mechanisms, exocrine secretion) which are mostly defined by cutaneous non-neuronal cell populations. Finally, we close by summarizing data suggesting that selected channels are also involved in skin diseases such as e.g. atopic dermatitis, psoriasis, non-melanoma cancers and malignant melanoma, genetic and autoimmune diseases, etc., as well as in skin ageing.

Cutaneous squamous cell carcinoma with mucinous metaplasia on the sole associated with high-risk human papillomavirus type 18

A case of superficially invasive cutaneous squamous cell carcinoma (SCC) of the sole containing numerous mucin-producing vacuolated cells resembling "signet-ring" cells is reported. The 2 cellular components of the tumor, both squamous and mucinous, were atypical with pleomorphic nuclei, and expressed the same immunophenotype, consistent in weak and focal positivity for cytokeratin 5/6 and epithelial membrane antigen (EMA) and weak cytoplasmic and nuclear positivity for p16. Real-time PCR genotyping demonstrated the presence of high-risk human papillomavirus (HPV) type 18. We diagnose our case as "cutaneous SCC with mucinous metaplasia" and discuss the differential diagnoses with other skin tumors exhibiting mucin-containing cells, in particular with adenosquamous carcinoma and mucoepidermoid carcinoma. Although HPV 18 is not uncommon in cervico-vaginal pathology, where is often associated with mucinous adenocarcinoma or adenosquamous carcinoma of the cervix, its detection has been rarely reported in cutaneous SCC. In our case, the association of mucinous metaplasia and oncogenic high-risk HPV 18 in a cutaneous SCC may be of interest to the dermatopathologist. Further observations need to confirm whether the histopathologic finding of mucinous metaplasia in an atypical squamous cell proliferation could be a clue for investigating the presence of oncogenic high-risk HPV infection, with particular regard to HPV 18 subtype.

High throughput sequencing reveals diversity of Human Papillomaviruses in cutaneous lesions

There are at least 120 completely characterized human papillomavirus (HPV) types and putative new types are continuously found. Both squamous cell carcinoma of the skin (SCC) and other skin lesions commonly contain multiple cutaneous HPV types. The objective of this study was to achieve an improved resolution of the diversity of HPV types in lesions such as SCCs, actinic keratoses (AKs) and keratoacanthomas (KAs). Fresh frozen biopsies from 37 SCC lesions, 36 AK lesions and 92 KA lesions and swab samples from the top of the lesion from 86 SCCs and 92 AKs were amplified using the general HPV primers FAP and mixed to three pools followed by high throughput sequencing. We obtained 2196 reads with homology to HPV. In the pool of SCC/AK biopsies 48 different HPV types were found. Eighty-three types were found in the pool of SCC/AK swab samples and 64 types in the KA biopsies, respectively. For 9 novel putative HPV types most of the amplimer sequence was obtained, whereas for an additional 35 novel putative HPV types only partial amplimer sequences were obtained. Most of the novel putative types belonged to the genus Gamma. In conclusion, high throughput sequencing was an effective means to identify both known and previously unknown HPV types in putatively HPV-associated lesions and has revealed an extended diversity of HPV types.

Determination of the relationship between Basal cell carcinoma and human papilloma virus, based on immunohistochemistry staining method

Background:

Basal cell carcinoma (BCC) is the most common skin cancer among Caucasians, and in most cases, occurs in the sun-exposed areas. In recent years, in addition to many other etiologies such as exposure to UV radiation, and occasionally xeroderma pigmentosa, burns, tattoos, and pox scars, human papillomavirus (HPV) is also considered to have an etiologic role. Different studies were conducted with varied results in this regard.

Aims:

We evaluate this plausible relationship between HPV and BCC by means of immunohistochemistry (IHC) staining method.

Methods:

This is an analytic cross-sectional study in which 160 samples were selected randomly consisting of 80 BCC lesions and 80 safe margins. Sampling was done among paraffin-embedded blocks in pathology ward of Kashani and Alzahra hospitals, Isfahan-Iran, from 2004-2007. A section of each block was IHC stained for HPV immunoreactivity (DAKO, Denmark). This was followed by microscopic evaluation in terms of being positive or negative.

Results:

Fifty seven point five percent of the samples belonged to men and the others to women. In 10%, HPV marker was positive, both in lesion and margin. In 83.8% neither the lesions nor the margins were immunoreactive for HPV. Only in 5 cases (6.3%) the lesion was positive and the margin was negative for this marker. There was no case of immunoreactivity for HPV marker in margins, while it was negative in lesions. Our study results followed by McNemar analysis did not show a significant relationship between BCC incidence and HPV existence. This was consistent in both genders (P > 0.05, power > 90%).

Conclusion:

In this study we did not find a significant relationship between BCC and HPV, but based on review of articles it appears that large multicentric studies are to be conducted in this regard.

CDKN2A but not TP53 mutations nor HPV presence predict poor outcome in metastatic squamous cell carcinoma of the skin

Genetic alterations in metastatic cutaneous squamous cell carcinoma (CSCC) which might serve as prognostic biomarkers are not well investigated. We investigated the mutation status and protein expression of the CDKN2A (INK4a-ARF) and TP53 genes in metastatic CSCCs and correlated this with clinicopathological variables, HPV presence, and survival data. Sequence analysis was performed on formalin-fixed and paraffin-embedded tissue of 35 metastases and their primary tumors, and was correlated with immunohistochemical stainings for p53, p16 and p14. Beta-PV and alpha-PV DNA was detected using PCR-based assays. Kaplan-Meier and Cox regression methods were used for survival assessment. CDKN2A was mutated in 31% of the metastases and their primary tumors, while the TP53 gene was mutated in 51% of the metastases. P53 protein expression was significantly associated with missense type of mutations (p = 0.002). No persistent HPV types were detected. CDKN2A mutations were significantly associated with disease-specific death (p = 0.001). A significant difference was observed in disease-specific survival between patients with or without a CDKN2A mutation (p = 0.010), while this was not the case for TP53. At univariate Cox's regression analysis tumor size (p = 0.010), invasion depth (p = 0.030) and CDKN2A mutations (p = 0.040) were significantly related to shorter disease-specific survival. At multivariate Cox's regression only tumor size had an adverse effect on survival (p = 0.002). In conclusion, our study indicates that the CDKN2A mutation status might be of prognostic value in metastatic CSCCs. In most cases, CDKN2A and TP53 mutations are early genetic events in CSCC tumorigenesis. The possible role of HPV in metastatic CSCC needs further exploration.

Viral DNA detection and RAS mutations in actinic keratosis and nonmelanoma skin cancers

BACKGROUND

Actinic keratosis (AK) is a well-established precancerous skin lesion that has the potential to progress to squamous cell carcinoma (SCC). Basal cell carcinoma (BCC) is a locally aggressive slowly growing tumour that rarely metastasizes. A number of viruses have been proposed to play a role in the development of nonmelanoma skin cancers (NMSC), but the most plausible evidence to date suggests that cutaneous human papillomavirus (HPV) is the key instigating factor.

OBJECTIVES

To evaluate the prevalence of HPV, cytomegalovirus (CMV), herpes simplex virus (HSV) and Epstein-Barr virus (EBV) and investigate their relationship with the presence of RAS gene mutations in cutaneous lesions obtained from nonimmunosuppressed patients.

METHODS

HPV, CMV, HSV and EBV detection was performed using polymerase chain reaction (PCR) in skin biopsies (26 AK, 12 SCC and 15 BCC samples) that were collected from immunocompetent patients. The RAS mutation incidence was also investigated in all cutaneous lesions by use of PCR/restriction fragment length polymorphism and direct DNA sequencing.

RESULTS

Seventeen out of 53 (32%) skin lesions were found to be positive for HPV DNA. The highest incidences of HPV infection were five of 15 (33%) in BCC and four of 12 (33%) in SCC specimens. The HPV incidence was eight of 26 (31%) in AK and eight of 53 (15%) in normal skin tissue. Twelve out of 53 (23%) skin lesions were CMV-positive. The highest incidence of CMV infection was six of 15 (40%), observed in BCC specimens. The CMV incidence was two of 26 (8%) in AK and four of 12 (33%) in SCC. No normal skin biopsy was found to be positive for CMV. All cutaneous samples were negative for HSV and EBV DNA, as assessed by our PCR-based assays. Only three samples, one AK (4%), one BCC (6%) and one SCC (8%), were found to carry a G>T transversion at the second position of HRAS codon 12. Both HRAS mutant SCC and BCC biopsies were HPV- and CMV-positive, as well.

CONCLUSIONS

HPV DNA is detected in NMSC, AK and normal skin biopsies. Our results also indicate that CMV is involved in NMSC at higher levels than in premalignant lesions, whereas the virus was not detected in normal skin biopsies. HSV and EBV do not appear to be involved in the pathogenesis of cutaneous lesions. Moreover, we suggest that the HRAS codon 12 mutation is not a very common event in AK or NMSC. Finally, both viral infection and HRAS activation appear to represent independent factors in the aetiology of NMSC, samples of which were obtained from immunocompetent patients.

Prevalence of human herpes virus type 1 in epithelial skin cancer

BACKGROUND

Viral DNA may act as an oncogene, especially in skin and lymphoid organs. This group includes some human herpes virus.

OBJECTIVE

To identify human herpes virus type 1 DNA in pre-malignant and malignant skin samples of epithelial tumors comparing to normal skin to determine its role in carcinogenesis. METHODS - Forty-one patients with epithelial tumors were submitted to biopsies from tumor and normal skin. The control group comprised 41 biopsies from patients with other dermatoses than cancer. After DNA extraction, polymerase chain reaction was performed to identify 199-bp band. The results were statistically evaluated by Fisher and McNemar tests.

RESULTS

The virus was identified in 20 subjects without cancer and in 21 with skin cancer. From these, 11 expressed it only in tumor cells. This difference was not significant.

CONCLUSION

There seem to be no direct relation between viral findings in normal skin and skin cancer cells. It may act as a promoter or just coexist at the same site where a neoplastic transformation has already occurred.

Detection of human papillomavirus DNA in cutaneous squamous cell carcinoma among immunocompetent individuals

The presence of certain types of human papillomavirus (HPV) is a known risk factor for the development of anogenital squamous cell carcinomas (SCCs). A similar association has been hypothesized for cutaneous SCCs, although, to our knowledge, no studies to date have combined sensitive HPV DNA detection techniques with epidemiologic data controlling for known risk factors to explore the association. We designed a case-control study examining HPV prevalence using highly sensitive PCR-detection assays in tissue samples from 85 immunocompetent patients with histologically confirmed SCCs and 95 age-matched individuals without a prior history of skin cancer. A standardized interview was administered to all study subjects to collect information pertaining to potential confounding variables. The overall detection rate of HPV DNA was high in case lesions (54%) and perilesions (50%) and in both sun-exposed normal tissue (59%) and non-sun-exposed normal tissue (49%) from controls. In comparing case tissue to control tissue, there was no differential detection of HPV DNA across various HPV species. However, HPV DNA from beta-papillomavirus species 2 was more likely to be identified in tumors than in adjacent healthy tissue among cases (paired analysis, odds ratio=4.0, confidence interval=1.3-12.0). The high prevalence of HPV DNA detected among controls suggests that HPV DNA is widely distributed among the general population. However, the differential detection of HPV beta-papillomavirus species in tumors among cases suggests that certain HPV types may be involved in the progression of cutaneous SCCs.

Differential p53-mediated responses to solar-simulated radiation in human papillomavirus type 16-infected keratinocytes

In immunocompromised patients, cooperative effects of human papillomavirus (HPV) and ultraviolet (UV) radiation have been postulated in the development of non-melanoma skin cancers. The tumor suppressor p53 is a key component of the cellular response to genotoxic agents, such as UV radiation. We have previously demonstrated that in HPV16-infected cells, a higher E6* level was associated with a higher resistance to UV and oxidative stress. Using the two same SKv cell lines, the aim of the present study was to investigate p53 and p21 expression and cell death in HPV-infected keratinocytes in response to UV irradiation and to determine the role of HPV oncoprotein levels on the p53-mediated cellular response. We demonstrated that the weakly E6*-expressing level SKv-e cell line presented both higher cytotoxicity and apoptosis to UV. This high sensitivity was associated with both p53 and p21 nuclear accumulation, while a high E6* level and resistance were associated with no p53 accumulation and a p21 nuclear down-regulation after UV. Moreover, in SKv-e cell line, p21 promoter activation was p53 dependent. Our results suggest that an alteration and/or a modulation of the p53-p21 pathway in response to UV could be determinant for HPV-infected keratinocyte survival and HPV-associated carcinogenic process.

Prevalence of mucosal types of human papillomavirus in skin lesions in north part of Iran

Human papillomaviruses (HPVs) consist of more than 100 types and are known to be associated with numerous malignant tumors, including carcinomas of the mucosal and cutaneous epithelium. Non-melanoma skin cancer (NMSC) is the most frequently occurring malignancy worldwide in the Caucasian population. Some studies have shown that NMSC biopsy specimens harbor cutaneous as well as mucosal human papillomavirus, suggesting that mucosal types may play a role in development and progression of the tumor in skin. To investigate the presence of mucosal HPV types in skin lesions, we performed a retrospective study in which 288 paraffin embedded biopsies from benign and malignant skin lesions (NMSC) were collected. Using nested PCR with MY09/11 and GP5+/6+ primers mucosal HPVs were detected in 25.7% of malignant specimens, but just in 0.7% of benign lesions. Direct sequencing revealed HPV18 as the most frequent type, which was found in 75% of HPV-positive specimens. HPV16 and HPV56 were also detected, 22.3 and 2.7%, respectively. These findings suggest that, high-risk mucosal HPV types recently identified as significant risk factors for cervical cancer, may also represent a risk factor for non-melanoma skin cancer.

Diversity of cutaneous human papillomavirus types in individuals with and without skin lesion

BACKGROUND

Human papillomavirus (HPV) is ubiquitous on the skin of normal and immunosuppressed hosts.

OBJECTIVE

We describe the diversity of HPV types in skin specimens using PCR-sequencing directly and after cloning with FAP59/64 or HVP2/B5 primers.

STUDY DESIGN

Cross-sectional analysis of skin swabs.

RESULTS

Seventy-five (92.6%) of 81 subjects provided samples that could be analysed with PCR (34 healthy controls <50 years old, 13 healthy controls > or =50 years old, 12 with actinic keratosis (AK), 8 with squamous cell carcinoma (SCC) and 8 renal transplant recipients). HPV DNA was detected more frequently with FAP59/64 (68/75, 91%) than with HVP2/B5 (9/75, 12%) (p<0.001). Agreement of typing results using FAP59/64 primers with both sequencing strategies was fair (mean kappa 0.56+/-0.19, 95% CI: 0.46-0.65). HPV species 1 and 2 of the beta-papillomavirus genus were associated with the presence of AK (OR=24.8, 95% CI: 2.3-262.6). A greater number of HPV types per sample was found in individuals with AK or SCC (p=0.046) or AK alone (p=0.02), than in healthy participants.

CONCLUSION

HPV infection on the skin is best evaluated with a combination of primers and sequencing strategies. Novel putative types were frequently detected in SCC. Skin lesions have a greater number of HPV types than normal skin.

Ungual Basal Cell Carcinoma on the Fifth Toe Mimicking Chronic Dermatitis: Case Study

BACKGROUND

The finger, toe, and nail unit are rare sites of basal cell carcinoma (BCC). Only a few patients with BCC of the foot have been described in the world literature, and ungual BCC is even less frequent.

OBJECTIVE

To discuss through a case report the clinical features and diagnosis of BCC of the foot.

METHODS

We report an unusual case of BCC of the nail unit of the fifth toe of an elderly woman that mimicked chronic dermatitis.

CONCLUSION

Our case clearly highlights the need for biopsy and histopathologic examination whenever we see inflammatory lesions with a loss of substance that are refractory to systemic or topical treatments.

Molecular diagnosis of infectious diseases in dermatology

The molecular diagnosis of infectious disease has been growing considerably over the past decade. Nucleic acid amplification techniques, such as polymerase chain reaction, ligase chain reaction, transcription-mediated amplification, and nucleic acid sequence-based amplification, provide highly accurate diagnosis of numerous bacterial, viral, fungal, and parasitic infections involved in a variety of dermatologic diseases. In addition, signal amplification with hybrid capture, branched-DNA assays, and in situ hybridization have been used to detect numerous viral pathogens with high degrees of sensitivity and specificity. New technology that involves the use of DNA and protein microarrays has also enabled the detection of a variety of genes and gene mutations. With time, these diagnostic assays are decreasing in cost, gaining approval of the U.S. Food and Drug Administration, and becoming easier and more efficient to use. In the future, these assays will be able to deliver rapid and accurate diagnosis of infectious diseases within a single clinic visit.

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with molecular diagnosis of infectious diseases in dermatology.

Human papillomaviruses of the mucosal type are present in some cases of extragenital Bowen's disease

BACKGROUND

Bowen's disease in the genital area is generally considered to be caused by mucosal high-risk human papillomaviruses (HPVs). However, the detection rate and spectrum of HPVs in extragenital Bowen's disease are various and it is not clear to what extent HPV is involved in its pathogenesis.

OBJECTIVES

To assess the degree of association of HPV in extragenital cases by examining detection rates, types, quantities and localization of HPV.

METHODS

A polymerase chain reaction (PCR) approach that we had previously established, which can give sensitive detection of a broad range of HPVs from cutaneous [including epidermodysplasia verruciformis-related HPVs (EV-HPVs)] to mucosal HPVs, was applied to samples from 41 patients with extragenital Bowen's disease and normal skin samples from 48 individuals. Semiquantitative L1-PCR and tyramide-based in situ hybridization (ISH) were also employed for positive cases.

RESULTS

HPVs belonging to the mucosal high-risk group were detected in three patients with Bowen's disease (7%; two HPV 16 and one HPV 33), with 10(1)-10(3) copy equivalents per diploid amount of cellular DNA. They were distributed among most nuclei of tumour cells but in none of the cells of adjacent normal skin. HPVs belonging to the cutaneous group were detected in two patients (5%; HPV 27 and HPV 76) at 10(-2)-10(-3) copy equivalents, the same level as in a normal skin specimen positive for type 23 EV-HPV. No positive signals were observed by ISH.

CONCLUSIONS

HPVs belonging to the mucosal high-risk group may participate in the development of extragenital Bowen's disease.

E6* oncoprotein expression of human papillomavirus type-16 determines different ultraviolet sensitivity related to glutathione and glutathione peroxidase antioxidant defence

Clinical observations of non-melanoma skin cancer in immunocompromised patients, such as organ transplant recipients, suggest co-operative effects of human papillomavirus (HPV) and ultraviolet (UV) radiation. The aim of the present study is to evaluate UV sensitivity and DNA damage formation according to antioxidant status in HPV16-infected keratinocytes. We used SKv cell lines, infected with HPV16 and well characterized for their proliferative and tumorigenic capacities. We showed that SKv cell lines presented various E6* (a truncated form of E6) RNA levels. We demonstrated that the higher oncoprotein RNA expression level was associated with a higher resistance to solar-simulated radiation, more specifically to UVB radiation and to hydrogen peroxide. Moreover, this high resistance was associated with a low oxidative DNA damage formation after UV radiation and was related to high glutathione content and glutathione peroxidase activities. Therefore, the results of our study suggest that E6* levels could modulate the glutathione/glutathione peroxidase pathway providing a mechanism to protect HPV-infected keratinocytes against an environmental oxidative stress, such as UV radiation.

Detection of various types of human papillomavirus DNA, mainly belonging to the cutaneous-group, more frequently in normal tissue than in squamous cell carcinomas of the lip

BACKGROUND

Mucosal high-risk human papillomaviruses (HPVs), such as type 16, are detectable in oral cancers, especially of the oropharynx and tonsils, and there is evidence that they play a pathogenetic role in some cases. However, information is limited about their significance for cancers of the vermilion of the lip.

OBJECTIVE

To determine the detection rate, types and localization of HPVs in squamous cell carcinomas (SCCs) of the lip.

METHODS

Nested PCR for cutaneous HPVs, including epidermodysplasia verruciformis-related HPV (EV-HPV), and single PCR for mucosal HPVs, were conducted for a total of 27 SCCs and normal samples from 30 individuals. Tyramide-based in situ hybridization (ISH) was also applied.

RESULTS

Various types of HPVs were detected, particularly from normal individuals. Among the kinds of the HPV types detected in this study, half were found by PCR using a primer pair, which we newly designed. The prevalence of HPV was 5 out of 27 SCCs (ca. 18%) and 10 out of 30 normal individuals (ca. 33%). They were the entire cutaneous-group except for two, from one SCC and one normal individual.

CONCLUSION

On the surface of the normal lip various types of mainly cutaneous-group HPVs may be present, but there does not appear to be any obvious association with SCCs developing in this site.

Human papillomavirus and extragenital in situ carcinoma

BACKGROUND

The relation between human papillomavirus (HPV) and extragenital Bowen's disease (BD) is controversial.

METHODS

This study used in situ hybridisation to evaluate the rate of HPV in extragenital cutaneous BD and investigated possible relations with immune status and exposure of skin to light.

RESULTS

HPV DNA was detected in 58% of 69 samples from 50 patients. The percentage of HPV detection was not significantly higher in exposed (55%) than unexposed areas (65%), and no difference in HPV rate was found between immunosuppressed and immunocompetent patients.

CONCLUSION

Thus, this study confirms the high rate of HPV detection in extragenital cutaneous BD and suggests that there is no apparent relation concerning exposed areas and immune status.

Giant basal cell carcinoma associated with human papillomaviruses infection

Different criteria have been used to define giant basal cell carcinoma (BCC). However, the majority of tumors of 10 cm or greater in diameter have a characteristic clinical and histopathologic presentation. As a group, these tumors often show metastatic spread as opposed to all other BCCs that rarely metastasize. We present an additional patient with a giant BCC greater than 100 cm2. This tumor had a characteristic location and infiltrative growth pattern. Unusual features of this tumor included a lack of expression of BCL-2 with a greater proportion of cycling tumor cells expressing proliferation markers than conventional BCC, as well as expression of anogenital human papillomaviruses (HPV) subtypes with oncogenic potential. The association of HPV with BCCs has rarely been studied and may not be identical to HPV-induced genital squamous cell carcinomas. However, the findings in this patient suggest that HPV may play a role in the development of some chronic giant BCCs.

BCL-2–Related Apoptosis Markers in Cutaneous Human Papillomavirus-Associated Lesions

BACKGROUND

Human papilloma virus (HPV) is an etiological agent in benign and malignant epithelial tumors. Resistance to apoptotic stimuli by viral strategies represents an immunologic escape mechanism during virus-induced tumor development and is critical for efficient replication of the virus.

OBJECTIVE

The aim of the present study was to investigate a role of bcl-family proteins in the anti-apoptotic pathways modulated by low-risk HPVs in the development of benign HPV-associated cutaneous tumors.

METHODS

Forty lesional biopsy specimens from HPV-associated cutaneous lesions and 11 non-lesional control skin biopsies were studied by immunohistochemical analysis for the differential expressions of HPV antigens, the pro-apoptotic bax protein, and the anti-apoptotic bcl-2 and bcl-x proteins.

RESULTS

Compared with the normal epidermis, bcl-2 and bcl-x expression were significantly reduced in the lesional epidermis. Bax was expressed in HPV-associated cutaneous lesions, although the expression did not reveal a significant deviation from that in normal skin.

CONCLUSION

These findings indicate a discordant expression of bcl-2/ bcl-x and bax proteins in HPV-associated skin lesions and suggest that low-risk HPVs mediate other pathways that bypass the action of anti-apoptotic bcl-2 and bcl-x proteins. The presence of bax expression with a prominent decrease in bcl-2/ bax ratio and the lack of massive apoptosis in HPV-associated benign epithelial lesions may imply that interference with the pro-apoptotic proteins of bcl-family may constitute one of the several mechanisms mediated by HPV oncoproteins for the suppression of apoptotic process.

Vaccination of rabbits with an adenovirus vector expressing the papillomavirus E2 protein leads to clearance of papillomas and infection

Cervical cancer arises from lesions caused by infection with high-risk types of human papillomavirus (HPV). Therefore, vaccination against HPV could prevent carcinogenesis by preventing HPV infection or inducing lesion regression. HPV E2 protein is an attractive candidate for vaccine development because it is required for papilloma formation, is involved in all stages of the virus life cycle, and is expressed in all premalignant lesions as well as some cancers. This study reports vaccination against E2 protein using a rabbit model of papillomavirus infection. A recombinant adenovirus (Ad) vector expressing the E2 protein of cottontail rabbit papillomavirus (CRPV) was tested for therapeutic efficacy in CRPV-infected rabbits. Primary immunization with the Ad-E2 vaccine, compared to immunization with a control Ad vector, reduced the number of papilloma-forming sites from 17 of 45 to 4 of 45. After booster immunization, vaccinated rabbits formed no new papillomas versus an additional 23 papillomas in rabbits that received the control vector. Papillomas in the Ad-E2 vaccinees were significantly smaller than those in the control rabbits, and all four papillomas in the Ad-E2 vaccinated rabbits regressed. No CRPV DNA was detected either in the regression sites or in sites that did not form papillomas, indicating that the vaccination led to clearance of CRPV from all infected sites.

Human papillomaviruses and non-melanoma skin cancer

Epidemiological and experimental studies have overwhelmingly confirmed human papillomaviruses as important causal agents in anogenital carcinogenesis. A role for human papillomaviruses has also been proposed in a diverse range of other malignancies, and particular interest has focused on non-melanoma skin cancer, the commonest malignancy in fair-skinned populations worldwide. Although the evidence for this is considerably less convincing than for anogenital cancer, important epidemiological and functional data have emerged over the past year that have furthered our understanding of the possible contribution of human papillomaviruses to skin cancer. Epidemiological human papillomavirus DNA detection studies have shown associations with non-melanoma skin cancer, but have also emphasized the ubiquity of epidermodysplasia verruciformis human papillomavirus types in normal skin, hair follicles and benign hyperproliferative disorders, as have seroepidemiological approaches. Functional investigations have demonstrated mechanistically relevant interactions between the virus and ultraviolet radiation, host cytokines and cellular proteins including p53 and the pro-apoptotic protein Bak. Taken together, these data have advanced our understanding of the contribution of human papillomaviruses to malignant transformation in cutaneous keratinocytes, but further research is required before a causal association between human papillomaviruses and skin cancer is reliably confirmed.