Background/Aims—Non-melanoma skin cancers frequently harbour multiple human papillomavirus (HPV) types. A recent report suggests that a polymorphism of the p53 tumour suppressor gene that results in the substitution of a proline residue with an arginine residue at position 72 of the p53 protein might act as a risk factor in HPV associated malignancies. This study aimed to determine the following: (1) the relation between HPV infection and the development of cutaneous squamous cell carcinoma (SCC), and (2) whether there is a correlation between p53 codon 72 polymorphism and the development of SCC.
Methods—Blood samples were taken from 55 patients with skin cancer (both renal transplant recipients and immunocompetent patients with skin cancer) and 115 ethnically matched volunteers. A polymerase chain reaction based assay was used to determine p53 codon 72 genotypes. In addition, 49 benign and malignant lesions from 34 of the patients with skin cancer and 20 normal human skin samples from 20 of the control volunteers were examined for HPV.
Results—The proportions of p53 codon 72 genotypes found were 78% arginine homozygous, 2% proline homozygous, and 20% heterozygous among patients with skin cancer and 79% arginine homozygous, 3.5% proline homozygous, and 17.5% heterozygous among the control population. Statistical analysis showed no significant differences in the distribution of the two p53 isoforms between the patients with skin cancer and the control population. The predominant viral types detected in both the patients and the control group were EV associated HPVs, although the incidence was lower in normal skin samples than in malignant lesions or viral warts.
Conclusions—These results suggest that in a Celtic population there is no correlation between the presence of HPV, the p53 codon 72 arginine polymorphism, and the development of skin cancer.
Key Words: p53 codon 72 polymorphism • human papillomavirus • skin cancer
The association between human papillomavirus (HPV) infection and non-melanoma skin cancers (NMSCs) such as squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) is not yet fully understood. We analysed the prevalence and spectrum of cutaneous beta-HPV types and mucosal/genital HPV types in paired biopsies (tumour and corresponding perilesional skin) obtained from 50 BCC immunocompetent patients. A small group of SCC patients (n=9) was also included. We also evaluated some previously postulated risk factors for HPV infection in NMSC patients.
All biopsies were negative for mucosal/genital HPV types. Overall, beta-HPV DNA was detected more often in SCC compared to BCC patients (78% vs 55% of total samples). The frequency of infection increased with the patient’s age [OR=4.88 (95% CI 1.29-18.39)]. There was no significant correlation between beta-HPV positivity and sex, skin type and UV exposure. The prevalence of beta-HPV species 1 types was significantly higher than those belonging to other beta-HPV species in biopsies from BCC (p=0.022) but not from SCC subjects (p=0.091). There was no significant difference in the overall prevalence of beta-HPV infection and the number of viral types between tumour lesions and perilesional skin. BCC samples were significantly more likely to be infected with beta-HPV species 1 types compared to perilesional skin (p=0.036) and showed a higher frequency of mixed infections (p=0.028).
These findings demonstrate that beta-HPV types belonging to species 1 are the most common HPV types detected in the skin of BCC patients. Moreover beta-1-HPV types and mixed infections are significantly more frequent in tumour samples than in healthy perilesional skin. Our results suggest that beta-1-HPVs as well as co-infection with more than one viral type could be important in NMSC and in particular in BCC.
Further studies aimed to compare the biological activity of viral types in tumours and in healthy skin (viral replication and expression, interference of infection with cellular functions) are necessary to understand the role of HPV infection in skin cancer.
Human papillomavirus; Beta-HPV; Non-melanoma skin cancer; Basal cell carcinoma; Squamous cell carcinoma; Perilesional skin
The first evidence of an association between HPV and non-melanoma skin cancer comes from patients with epidermodysplasia verruciformis (EV). EV is a rare heritable disease characterized by cutaneous warts that display not only a high rate of progression to squamous cell carcinoma on sun-exposed sites, but also a strong predisposition to infection by β-HPVs, for which HPV 5 and 8 predominate. Two EV genes (EVER1 and EVER2) have been identified, and we tested the hypothesis that variation in the EVER2 gene (rs7208422) is related to seropositivity to HPV (of the genus β types) and risk of squamous cell carcinoma in a population-based case-control study of SCC (n = 239 cases and 432 controls). Among controls, variant genotype was associated with β-HPV seropositvity (OR = 2.3, 95%CI = 1.2–4.3), specifically HPV5 or 8 seropositivity (OR = 2.4, 95%CI = 1.1–5.1) and seropositivity for multiple β-HPV types (OR =2.7, 95%CI =1.1–6.6). Furthermore, variant genotype was also related to SCC risk [adjusted OR for homozygous variant versus homozygous wild type for the EVER2 polymorphism 1.7, 95% CI 1.1–2.7]. These data provide evidence for a role of genetic variation in the EVER2 gene in β-HPV infection and risk of SCC, shedding light on the link between HPVs and skin cancers.
human papillomavirus; skin cancer; EVER2
Cancer of the cervix uteri is the second most common cancer among women worldwide. The association of human papillomavirus (HPV) infection with cervical carcinogenesis is well documented. This is a pilot study aiming to studying the prevalence and the pattern of Human Papilloma Virus Type 16 (HPV16) by immunostaining in the tissues of cervical carcinomas of Ethiopian women.
20 specimens of uterine cervical carcinomas were studied histopathologically and immunohistochemically for HPV16.
Histologically the specimens were classified as: Ten cases were Non Keratinized Squamous cell carcinoma (NKSCC), six cases were Keratinized Squamous Cell Carcinoma (KSCC) and four cases were Adenocarcinoma (ADC). Immunohistochemistry study showed positivity in eleven cases (55%); seven cases (35%) were non-keratinized squamous cell carcinoma; three cases (15%) were keratinized squamous cell carcinoma and one case (5%) belonged to the adenocarcinomas.
This study reveals a significant detection of HPV in Ethiopian women by the use of advanced techniques such as Immunohistochemistry (IHC). The data of this study suggested that the marked expression of the HPV 16 was in the less differentiated uterine cervix carcinomas.
Cancer cervix; HPV 16; immunohistochemistry; Ethiopia
Despite intensive study of high-risk mucosal human papillomaviruses (HPV), little is known of the epidemiology of cutaneous HPV. As part of a study of cutaneous squamous cell carcinoma and HPV among organ transplant recipients (OTR) from London and Oxford, we investigated the seroprevalence and risk factors for 34 HPV types (detected using Luminex technology) among 425 Caucasian OTR without skin cancer.
Overall, 86% of participants were seropositive to at least one HPV: 41% to mucosal alpha types, 33% to cutaneous alpha types, 57% to alpha types, 56% to beta, 47% to gamma types and 45% to other types (nu, mu, HPV101 and 103). In both centres, the most common types were HPV6 (33% and 26% for London and Oxford respectively), HPV8 (24% and 18%), HPV15 (26% and 29%), HPV17 (25% and 21%), HPV38 (23% and 21%), HPV49 (19% and 21%), HPV4 (27% and 23%), HPV65 (30% and 25%), HPV95 (22% and 20%), HPV1 (33% and 24%) and HPV63 (28% and 17%). The seroprevalence of 8 HPV types differed significantly (P < 0.05) between London and Oxford. Those individuals seropositive to multiple types of one genus were more likely to be seroreactive to multiple types of another genus. As expected, antibodies against mucosal alphaHPV types were more frequent in younger patients and among women. Sunbed use and sunbathing was associated with seropositivity to multiple gammaHPV (P-trend = 0.007) and self-history of abnormal smear was related to seroactivity to multiple betaHPV (P = 0.01). Skin type and other self reported markers of exposure to ultraviolet radiation were not consistently associated with any HPV types. No other distinguishing epidemiological features of transplant recipients with antibodies against single or multiple HPV types were identified.
Findings for mucosal HPV types were in line with results from previous studies. We observed differences in HPV seroprevalence between organ transplant recipients from two geographically close centres but no clear risk factor was found associated with cutaneous HPV seropositivity among organ transplant recipients. These findings have implications for interpretation of future seroepidemiology studies addressing the association between HPV and cutaneous SCC in OTR populations.
The pathogenic role of beta-HPVs in non melanoma skin cancer (NMSC), is not still completely understood, and literature data indicate that they might be at least cofactors in the development of certain cutaneous squamous cell carcinomas. However, only few reports contain data on basal cell carcinoma (BCC). The HPVs interact with many cellular proteins altering their function or the expression levels, like the p16INK4a and Akt. Our study aimed to determine the presence of different beta -HPV types and the expression of p16INK4a and Akt in BCC, the commonest NMSC, in the normal appearing perilesional skin and in forehead swab of 37 immunocompetent patients.
The expression of p16INK4a and Akt, by immunohistochemistry, and the HPV DNA, by nested PCR, were investigated in each sample.
No correspondence of HPV types between BCC and swab samples was found, whereas a correspondence between perilesional skin and BCC was ascertained in the 16,7% of the patients. In BCC, 16 different types of beta HPV were found and the most frequent types were HPV107 (15,4%), HPV100 (11,5%) and HPV15 (11,5%) all belonging to the beta HPV species 2. Immunohistochemistry detected significant p16INK4a expression in almost all tumor samples (94,3%) with the highest percentages (> 30%) of positive cells detected in 8 cases. A statistically significant (p = 0,012) increase of beta HPV presence was detected in p16INK4a strongly positive samples, in particular of species 2. pAkt expression was detected in all tumor samples with only 2 cases showing rare positive cells, whereas Akt2 expression was found in 14 out of 35 BCC (40%); in particular in HPV positive samples over-expressing p16INK4a.
Our data show that p16INK4a and pAkt are over-expressed in BCC and that the high expression of p16INK4a and of Akt2 isoform is often associated with the presence of beta-HPV species 2 (i.e. HPV 15). The association of these viruses with the up-regulation of p16INK4a and Akt/PI3K pathway suggests that in a subtype of BCC these viruses may exert a role in the carcinogenesis or in other, still undefined, biological property of these tumors. If this particular type of BCC reflects a different biology it will remain undisclosed until further studies on a larger number of samples will be performed.
HPVs; BCC; p16INK4a and Akt1/2; skin cancer
An increasing number of studies report that genus β human papillomaviruses (HPVs) are associated with skin cancer, with suggestions of specificity for squamous cell carcinoma (SCC) of the skin. We have conducted a systematic examination of HPV DNA in tumors from immunocompetent hosts, including SCC and basal cell carcinoma (BCC), using a highly sensitive methodology and population-based samples to test the hypothesis that a differential prevalence of β-HPVs exists between SCC (n = 101) and BCC (n = 101) tumors. When testing for all known β-HPV types, we found no significant difference in HPV prevalence between the two histologies. However, SCC lesions were significantly more likely to be infected with HPV genus β-species 1 (includes types 5 and 8), than BCC samples (P = 0.01); this difference was not observed for any other species. A histologic difference was also observed for those HPV types previously reported to be important in skin cancer (P = 0.003). SCC samples showed a higher rate of infectivity (that is, were positive for multiple types) than BCC tumors (P = 0.02). These data highlight the potential importance of various genus β-HPV types, in particular genus β-species 1 in SCC, and support the hypothesis of a behavioral difference of the virus within the two major histological skin cancers.
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 β-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 β-papillomavirus species in tumors among cases suggests that certain HPV types may be involved in the progression of cutaneous SCCs.
The relationship between Human Papillomavirus (HPV) infection and conjunctiva cancer is controversial. HPV detection will provide more information about the role of this infectious agent in the biology of conjunctiva cancer. In the present study, DNA extracted and purified from 36 Conjunctival Squamous Cell Carcinomas (CSCC) was evaluated by PCR for HPV DNA sequences. The results were correlated with the clinical and histopathological variables.
The results showed that HPV DNA was present in 8 CSCC samples (22%); HPV16 was the sole type detected. Significant association was found between HPV detection and the limbus tumor subtype (p = 0.03). All the samples were non-metastatic squamous cell carcinoma.
The HPV presence in CSCC from Mexican patients is not a common event.
conjunctiva; carcinoma; HPV
Histologic changes suggesting HPV infection are occasionally found adjacent to squamous cell carcinoma or in squamous papilloma of the esophagus, but the relationship between HPV infection and benign and malignant squamous lesions of the esophagus is not yet dear. The aim of this study was to examine the role of HPV in squamous lesions of the esophagus. Microscopic examination with emphasis on HPV infection was done on 15 cases of squamous cell carcinoma and 26 cases of squamous papilloma. In situ hybridization technique for wide-spectrum HPV probe was performed on 35 endoscopically biopsied esophageal tissues. Among the histologic parameters suggesting HPV infection, acanthosis was the most frequent finding: 100.0% in benign and malignant esophageal lesions, and koilocytosis and intraepithelial capillary loops were the second (92.7%).: Dyskeratosis, basal cell hyperplasia and bi- or multinucleation were 52.3%, 44.0% and 34.1% in frequency, respectively. On in situ hybridization study, the HPV DNA expression rates of 10 squamous cell carcinomas with evidence of HPV infection and 15 carcinomas without evidence of HPV infection were 60.0% and 33.3%, respectively. In contrast to the carcinoma cases, only one (10.0%) of 10 squamous papillomas revealed positive signal. In conclusion, HPV infection is strongly associated with squamous cell carcinoma, but the causal relation of HPV to squamous papilloma is inconspicous.
To investigate the complex interplay between human papilloma virus (HPV) infection and p53 gene alteration in 92 head and neck squamous cell carcinoma (HNSCC) and 28 leukoplakia samples from eastern India.
DNA isolated from the patient samples was subjected to HPV detection, loss of heterozygosity (LOH) analysis of the chromosome 17p region harbouring p53, genotyping at the p53 codon 72 locus and sequencing of the entire p53 gene to identify somatic mutations. Codon 72 heterozygotes carrying the p53 mutation were further cloned and resequenced to identify the allele harbouring the mutation.
HPV positivity in the HNSCC samples was 69%; 21% of the HNSCC were found to harbour p53 mutations in the coding region of the gene. The absence of the p53 mutation in HPV positive tumours was statistically significant compared to the HPV negative tumours (p = 0.01), but the same did not hold true for p53 LOH (p = 1.0). Among the germline p53 codon 72 heterozygotes, the Pro allele was preferentially lost (p = 0.02) while the Arg allele was mutated in the majority of cases. The risk of HPV mediated tumourigenesis increased with the increase in number of Arg alleles at the codon 72 locus.
It is proposed that genetic and epigenetic alteration of p53 follow distinct pathways during the development of HNSCC from normal epithelium via dysplasia. The p53 mutation and HPV mediated p53 inactivation possibly constitute two independent pathways of tumourigenesis.
Human papillomavirus (HPV) infections cause a significant global health burden, predominantly due to HPV-associated cancers. HPV infects only the epidermal cells of cutaneous and mucosal skin, without penetration into the dermal tissues. Infections may persist for months or years, contributed by an array of viral immune evasion mechanisms. However in the majority of cases immunity-based regression of HPV lesions does eventually occur. The role of the innate immune response to HPV in persistence and regression of HPV infection is not well understood. Although an initial inflammatory infiltrate may contribute to disease regression, sustained inflammation at the HPV-induced lesions, characterized by macrophage and neutrophil infiltration, has been observed in persistence. Pathogen-associated molecular patterns (PAMPs) are important in innate recognition. The double stranded DNA and an L1 and L2 capsid components of the HPV virion are potential PAMPs that can trigger signaling through cellular pattern recognition receptors, including toll-like receptors (TLR). TLR expression is increased in regressing HPV disease but is reduced in persistent lesions, suggesting a role for TLR in HPV regression. With regard to the adaptive immune response, a key indicator of regression in humans is infiltration of the lesion with both CD4 and CD8 T cells. In individuals with persistent lesions, CD8 T cell and immune suppressive regulatory T cells (Tregs) infiltrate the infection site. There is no association between persistence or regression and the presence of serum antibodies to the viral capsid antigens of HPV. There is still much to be learned about the immunological events that trigger regression of HPV disease. Understanding the viral and host factors that influence persistence and regression is important for the development of better immunotherapeutic treatments for HPV-associated disease.
Adaptive immunity; epidermis; immune evasion; innate immunity; papillomavirus; persistence; regression.
There is an increasing evidence for the role of high risk human papillomavirus (HPV) in the pathogenesis of oral squamous cell carcinoma (OSCC). The purpose of this study is to evaluate the relevance of HPV infection to the survival and prognosis of OSCC.
Fifty-two patients with OSCC were followed from 4 to 88 months with a median of 50.7 months. HPV DNA was identified in formalin-fixed, paraffin-embedded tumor specimens by nested PCR with MY09/MY11 and GP5+/GP6+ primer pairs and the HPV genotype was determined by direct DNA sequencing. Association between the HPV status and risk factors for cancer as well as tumor-host characteristics were analyzed. Survival curves were calculated by the Kaplan-Meier method and analyzed using the log-rank test.
HPV was found in 40.4% of the tumors with HPV16 accounting for 63.5%, HPV18 for 30.8%, HPV6 for 3.9% and HPV11 for 1.8%. No infection with more than one HPV genotype was detected. HPV infection was significantly associated with poor histological grade, TNM stage I–II, alcohol usage and no smoking status. Multi-variate analysis showed that HPV had an independent prognostic effect on the overall survival after adjusting other confounding factors such as histological grade, TNM stage and tobacco usage. The presence of HPV was significantly correlated with a better survival in patients with OSCC.
HPV infection can act as an independent predictor for the survival and prognosis of OSCC.
human papillomavirus (HPV); oral squamous cell carcinoma (OSCC); survival analysis
UV exposure and p53 mutations are major factors in non-melanoma skin cancer, whereas a role for HPV infections has not been defined. Previous data demonstrated the wtp53-mediated degradation of cutaneous HPV20E6 by caspase-3. ΔNp63α and hot-spot mutant p53R248W conveyed a protective effect on HPV20E6 under these conditions. We demonstrate a differential regulation by wtp53 of the E6 genes of cutaneous types HPV4, HPV5, HPV7, HPV27, HPV38, HPV48, HPV60 and HPV77. Caspase- or proteasome-mediated down-regulation was HPV type dependent. Mutant p53R248W up-regulated expression of all these E6 proteins as did ΔNp63α except for HPV38E6 which was down-regulated by the latter. None of these cellular proteins affected HPV41E6 expression. Ectopic expression of both mutp53R248W and ΔNp63α in the normal NIKS keratinocyte cell line harbouring endogenous p53 and p63however led to a down-regulation of HPV20E6. We demonstrate that HPV20E6 expression in these cells is modulated by additional, yet unidentified, cellular protein(s), which are not necessarily involved in apoptosis or autophagy. We further demonstrate proliferation of HPV20E6-expressing keratinocytes. Levels of proteins involved in cell cycle control, cyclin-D1, cdk6 and p16INK4a, phosphorylated pRB, as well as c-Jun and p-c-Jun, were all increased in these cells. HPV20E6 did not compete for the interaction between p16INK4a with cyclin-D1 or cdk6. Phosphorylation of pRB in the HPV20E6 expressing cells seems to be sufficient to override the cytokenetic block induced by the p16INK4a/pRB pathway. The present study demonstrates the diverse influence of p53 family members on individual cutaneous HPVE6 proteins. HPV20E6 expression also resulted in varying protein levels of factors involved in proliferation and differentiation.
Human papillomavirus (HPV) infection accounts for about 40-50% of all cases of penile carcinoma suggesting that other factors, including host genetic status, are involved in neoplastic transformation. In this perspective, STK11 gene, which has been found frequently mutated in HPV-related cervical carcinoma, has been analyzed in HPV-positive and HPV-negative invasive penile cancers to establish its mutational status and the possible correlation of HPV infection with specific genetic alterations.
Genomic DNAs extracted from 26 cases of penile squamous cell carcinoma were analyzed for genetic alterations in the exons 1 to 9 of STK11 gene by quantitative real-time PCR. Ratios of potentially deleted and non-deleted exons were indicative of specific loss of STK11 coding regions. DNA samples of 5 cancer cases were subjected to standard PCR amplification of STK11 exons 1 to 9 and analyzed for somatic mutations by direct nucleotide sequencing analysis.
Heterozygous deletions of STK11 exon 1 and 2 were identified in 2 out of 14 HPV-positive (14.3%) and 1 out of 12 HPV-negative cases (8.3%). Complete nucleotide sequencing analysis of exons 1 to 9 showed a single nucleotide change upstream the exon 2 coding region in 1 out of 5 penile carcinoma samples.
The present results suggest that single nucleotide mutations and/or deletions of STK11 gene are rare events in penile cancer. Moreover, no significant association was observed between STK11 alterations and HPV infection in these tumors.
HPV; STK11; Somatic mutations; Penile cancer
AIM: To examine the prevalence of genital type human papilloma virus (HPV) and mutations at codons 12, 13, and 61 in H, Ki, and N-ras in CIN III and early invasive squamous cell carcinomas of the cervix. METHODS: Prevalence of HPV was examined in 20 CIN III and 20 stage I and II cervical carcinomas, using non-isotopic in situ hybridisation (NISH) and solution phase polymerase chain reaction (PCR). In addition, mutations at codons 12, 13, and 61 were examined in H, Ki, and N-ras in these CIN III and early invasive squamous cell carcinomas, to assess the prevalence of ras gene point mutations and to define where in the pathobiology of squamous cell carcinoma such events occur. A non-isotopic PCR/RFLP assay was used to define these mutations. RESULTS: Of the 20 CIN IIIs examined, 19 contained HPV 16 DNA sequences by PCR and NISH. Dual infection was not uncovered. The 20 early (stage I and II) invasive squamous cell carcinomas showed predominant HPV 16 positivity (17/20), with one case HPV 18 positive, confirmed on PCR and NISH. Activating mutations were not identified in any of the CIN III cases. Only one stage I, HPV 16 positive carcinoma showed an activating mutation in H-ras codon 12, which was not present in adjacent normal ectocervical mucosa from the same patient. CONCLUSIONS: ras Activation does not appear to occur in conjunction with HPV infection, particularly of HPV 16 infected high grade cervical intraepithelial neoplasia, or to occur commonly in early cervical squamous cell carcinoma. The postulated model of HPV linked carcinogenesis suggests malfunctional control of viral transcription as a necessary component of neoplastic progression. It is also clear that host gene alterations are equally necessary for HPV linked carcinogenesis to occur.
Epidemiological evidence suggests that alcohol intake, use of tobacco, ingestion of mycotoxins and nitrosamines and nutritional deficiencies are high-risk factors for the development of oesophageal cancer. Similarly, viral infections have been postulated to play a role in some tumours. However, the molecular events underlying the development of oesophageal carcinoma are poorly understood as yet. Loss of p53 tumour-suppressor gene function has been found in different human malignancies, and it can occur in a variety of ways, including gene mutation and interaction with the E6 protein of oncogenic human papillomaviruses (HPVs). Because the oesophageal mucosa is potentially exposed to mutagens and HPVs, we studied DNA samples derived from nine HPV-positive squamous cell carcinomas and 12 HPV-negative tumours. Exons 5-9 of the p53 gene containing phylogenetically conserved domains were examined using the polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) technique. HPV detection was done using DNA in situ hybridisation with biotin-labelled HPV DNA probes. Mutations were detected in eight (38%) out of the 21 cases. Three mutations were found in exons 5/6, three in exon 7 and two in exon 8/9. Six (50%) of the 12 HPV-negative carcinomas showed p53 mutations. Two (22.2%) of the nine HPV-positive carcinomas were found to contain p53 mutations as well; one contained HPV 16 DNA sequences and showed p53 mutation in exon 8/9, and the other was HPV 6/11 positive with the mutation in exon 5/6. Although mutations were more common in HPV-negative tumours (50.0% vs 22.2%), the difference in p53 mutations in HPV-positive and -negative tumours did not reach statistical significance (P = 0.1946). These data indicate that inactivation of the p53 gene is a frequent event in oesophageal squamous cell carcinomas and such an inactivation might be an important molecular pathway for the development of oesophageal cancer. The findings of p53 mutations in HPV-positive oesophageal carcinomas suggest that HPV and p53 mutation were not mutually exclusive events. The presence of frequent mutations of p53 gene in both HPV-positive and -negative oesophageal carcinomas suggests a dominant role of environmental carcinogens in oesophageal carcinogenesis.
An extremely diverse group of human papillomavirus (HPV) types consisting of epidermodysplasia verruciformis (EV)-associated HPV types and other cutaneous HPV types (e.g., HPV types 2 and 3) is associated with nonmelanoma cancers and benign lesions of the skin. The frequent presence of multiple HPV types in single skin biopsy specimens of renal transplant recipients prompted us to develop PCR techniques for the detection of distinct (sub)groups of genotypically related cutaneous HPV types, i.e., three subgroups of EV-associated HPV types and two groups (A2 and A4) of other cutaneous HPV types. This approach generally allowed a reliable identification of HPV genotypes by direct sequencing of the PCR products, despite the frequent occurrence of multiple infections. The targeted spectrum of HPV types comprises 66 cutaneous HPV types including 21 putative novel HPV types. We also detected 17 putative novel HPV subtypes. We demonstrated that the skin of nearly all renal transplant recipients who developed various benign and (pre)malignant skin lesions was persistently infected with one or more EV-associated HPV types and/or HPV types belonging to groups A2 and A4. The frequency and distribution of EV-associated HPV and HPV types belonging to groups A2 and A4 were similar in biopsy specimens from hyperkeratotic papillomas (77.5%), squamous cell carcinomas (77.8%), and actinic keratoses (67.9%) but appeared to be lower in specimens of basal cell carcinomas (35.7%), benign lesions (38.5%), and clinically normal skin (32.3%). These findings suggest that renal transplant recipients are prone to persistent cutaneous HPV infection. Our data do not support the existence of high-risk cutaneous HPV types.
Human papillomavirus (HPV) has been confirmed as the primary etiological factor that transforms cervical epithelia into cancer. The presence of HPV in oral cancers suggests that HPV may play a similar role in transforming the oral epithelia. A high degree of variability in the prevalence of HPV in oral cancers has been found, however, raising questions regarding its role in the transformation and development of oral cancers. The goal of this study was to test our hypothesis that high-risk HPV strains HPV16 and HPV18 will alter the phenotype of transformed oral squamous cell carcinoma cell lines, CAL27, SCC-15 and SCC-25 in vitro.
CAL27 cells transfected with HPV18, HPV16, as well as HPV16/18 co-transfectants, demonstrated significant increases in proliferation, adhesion and cell spreading compared with non-transfected controls. These observed differences were correlated with a small level of increased cell survival. SCC-15 cells, however, displayed a differential response to HPV transfection, with only HPV18-transfectants demonstrated changes to proliferation. Interestingly, SCC-25 cells displayed a more complex response, with HPV16-induced increases in cell proliferation, viability and cell spreading, while HPV18- and 16/18-transfectants exhibited reduced adhesion and proliferation.
Determining the potential of specific high-risk HPV strains to alter phenotypic behaviors of already transformed oral carcinomas is a critical step in providing more accurate prognosis and treatment options for oral cancer patients. The identification of differential responses to specific HPV strains among oral cancers suggests a more significant, complex and multifactorial role of HPV, not only in transforming, but also in modulating, the phenotype and treatment responsiveness of precancerous and cancerous oral lesions. This study provides some of the first evidence to help identify the important molecular markers for pathways that could be used to determine the most effective and appropriate treatment plans for oral cancer patients with concomitant oral HPV infections.
Human papilloma virus (HPV) infection of the uterine cervix is linked to the pathogenesis of cervical cancer. Preclinical in vitro and in vivo studies using HPV-containing human cervical carcinoma cell lines have shown that the mammalian target of rapamycin (mTOR) inhibitor, rapamycin, and epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor, erlotinib, can induce growth delay of xenografts. Activation of Akt and mTOR are also observed in cervical squamous cell carcinoma and, the expression of phosphorylated mTOR was reported to serve as a marker to predict response to chemotherapy and survival of cervical cancer patients. Therefore, we investigated: a) the expression level of EGFR in cervical squamous cell carcinoma (SCC) and high-grade squamous intraepithelial lesions (HSIL) versus non-neoplastic cervical squamous epithelium; b) the state of activation of the mTOR pathway in these same tissues; and c) any impact of these signal transduction molecules on cell cycle. Formalin-fixed paraffin-embedded tissue microarray blocks containing 20 samples each of normal cervix, HSIL and invasive SCC, derived from a total of 60 cases of cervical biopsies and cervical conizations were examined. Immunohistochemistry was utilized to detect the following antigens: EGFR; mTOR pathway markers, phosphorylated (p)-mTOR (Ser2448) and p-p70S6K (Thr389); and cell cycle associated proteins, Ki-67 and S phase kinase-associated protein (Skp)2. Protein compartmentalization and expression were quantified in regard to proportion (0-100%) and intensity (0-3+). Mitotic index (MI) was also assessed. An expression index (EI) for pmTOR, p-p70S6K and EGFR, respectively was calculated by taking the product of intensity score and proportion of positively staining cells. We found that plasmalemmal EGFR expression was limited to the basal/parabasal cells (2-3+, EI = 67) in normal cervical epithelium (NL), but was diffusely positive in all HSIL (EI = 237) and SCC (EI 226). The pattern of cytoplasmic p-mTOR and nuclear p-p70S6K expression was similar to that of EGFR; all showed a significantly increased EI in HSIL/SCC versus NL (p<0.02). Nuclear translocation of p-mTOR was observed in all SCC lesions (EI = 202) and was significantly increased versus both HSIL (EI = 89) and NL (EI = 54) with p<0.015 and p<0.0001, respectively. Concomitant increases in MI and proportion of nuclear Ki-67 and Skp2 expression were noted in HSIL and SCC. In conclusion, morphoproteomic analysis reveals constitutive activation and overexpression of the mTOR pathway in HSIL and SCC as evidenced by: increased nuclear translocation of pmTOR and p-p70S6K, phosphorylated at putative sites of activation, Ser2448 and Thr389, respectively; correlative overexpression of the upstream signal transducer, EGFR, and increases in cell cycle correlates, Skp2 and mitotic indices. These results suggest that the mTOR pathway plays a key role in cervical carcinogenesis and targeted therapies may be developed for SCC as well as its precursor lesion, HSIL.
mTOR pathway; cervical squamous carcinoma; high grade SIL; morphoproteomics
AIM: To investigate the presence of high-risk human papilloma virus (HPV) in esophageal squamous cell carcinomas (ESCCs) in a non-selected Mexican population.
METHODS: Cases with a pathological diagnosis of squamous cell carcinoma of the esophagus were obtained from Department of Pathology files, at the National Cancer Institute in Mexico City during the period between 2000 and 2008. Slides from each case were reviewed and cases with sufficient neoplastic tissue were selected for molecular analysis. DNA was extracted from paraffin-embedded tissue samples for polymerase chain reaction analysis to detect HPV DNA sequences. Demographic and clinical data of each patient were retrieved from corresponding clinical records.
RESULTS: HPV was detected in 15 (25%) of ESCCs. HPV-16 was the most frequently observed genotype, followed by HPV-18; HPV-59 was also detected in one case. Unfortunately, HPV genotype could not be established in three cases due to lack of material for direct sequencing, although universal primers detected the presence of HPV generic sequences. No low-risk HPV genotypes were found nor was HPV-16/18 co-infection. HPV presence in ESCC was not significantly associated with gender, age, alcohol consumption, smoking, anatomic location, or histologic grade. All patients belonged to low and very low socioeconomic strata, and were diagnosed at advanced disease stage. Male patients were most commonly affected and the male:female ratio in HPV-positive ESCC increased two-fold in comparison with HPV-negative cases (6.5:1 vs 3.1:1).
CONCLUSION: High prevalence of high-risk HPV in ESCC in Mexico does not support the hypothesis that HPV-associated ESCC is more common in areas with higher ESCC incidence rates.
Esophagus; Human papilloma virus; Squamous cell carcinoma; High-risk human papilloma virus
The functional role of UV irradiation, in combination with the E6 and E7 proteins of the cutaneous human papillomavirus (HPV) types in the malignant conversion of benign papillomatous lesions, has not been elucidated. Transgenic SKH-hr1 hairless mice expressing HPV-20 and HPV-27 E6 and E7 proteins in the suprabasal compartment were generated and exposed to chronic UV irradiation. Histological and immunohistochemical examination of skin samples revealed enhanced proliferation of the epidermal layers and papilloma formation in both transgenic strains in comparison to what was observed with nontransgenic mice. Squamous cell carcinoma developed in the HPV-20 E6/E7 transgenic line as well as in the HPV-27 E6/E7 transgenic line. Several weeks after cessation of UV-B exposure, enhanced proliferation, as measured by BrdU incorporation, was maintained only in HPV-20 transgenic skin. Keratin 6 expression was increased in the transgenic mice throughout all cell layers. Expression of the differentiation markers involucrin and loricrin was reduced and disturbed. p63α expression was differentially regulated with high levels of cytoplasmic expression in clusters of cells in the granular layer of the skin in the transgenic lines 20 weeks after cessation of UV-B exposure, in contrast to uninterrupted staining in the nontransgenic lines. p53 was expressed in clusters of cells in nontransgenic and HPV-27 transgenic mice, in contrast to an even distribution in a higher number of cells in HPV-20 transgenic animals.
Human papilloma virus causes benign and malignant abnormalities in different part of the body. The link between high risk types of HPV and some anogenital and aerodigestive tract cancer is well established. Oral HPV infection plays a role in developing oropharyngeal squamous cell carcinoma. We studied the prevalence of oral HPV in healthy individuals and its relative risk factors.
Saliva samples of 114 healthy subjects were collected for HPV DNA analysis. Volunteers completed questionnaires and signed a written consent. For data analysis descriptive statistic, chi square test and odds ratio was used.
The frequency of oral HPV in healthy individuals was 6.1 %(seven participant).The most frequent type was HPV-18 in five of them. HPV-6 and HPV-66 each was detected in one case. Relation of oral HPV positivity to demographic features and risk factors was not statistically significant.
The prevalence of oral HPV infection in our community is the same as many other communities of developing countries, stressing that HPV-18 were the dominant type.
Human Papilloma Virus (HPV); Oral Cancer; Saliva
The aim of the study was to determine the prevalence and genotypes of HPV infection in laryngeal cancer specimens, normal mucosa obtained from the surgical margin and laryngeal nodules using a novel high sensitive and specific SPF10 HPV DNA test, PCR/DEIA method and INNO-LiPA genotyping assay. The correlation between HPV presence and clinico-pathological features was analyzed. Tissue samples were collected from 93 primary laryngeal squamous cell carcinoma (LSCC), 49 specimens of normal mucosa and from 22 specimens of laryngeal nodules serving as control group. HPV DNA was amplified by the short PCR fragment (SPF10) primer set using HPV DNA enzyme immunoassay (DNA/DEIA) method and INNO-LiPA HPV genotyping assay. Human papillomavirus was detected in 33 (35.5%) of the 93 samples from LSCC, in 4 (8.2%) of 49 samples of the normal mucosa and it was not detected in any of the sample from the control group. Twenty-eight of 33 (81.8%) were positive for HPV-16, 6 of 33 (18.2%) were positive for HPV-18 and 5 of 33 (15.1%) were positive for HPV-33. Multiple infection was found in 5 of 33 (15.1%); 3 samples were positive for HPV-16 and HPV-33, 2 samples for HPV-16 and HPV-18. There was a statistically significant correlation between the presence of HPV in LSCC tumors and in control group samples and between the presence of HPV in the tumors and normal mucosa from the free surgical margin. The presence of HPV infection in 35.5% of the cases suggests a possible role in the etiology of laryngeal cancer and supports the role of high-risk types of HPV (16, 18 and 33) in LSCC. HPV infection is not likely to influence survival rates as an independent prognostic factor in patients with laryngeal cancer.
HPV; Laryngeal cancer; Normal mucosa; Control group; Survival
Human papillomavirus (HPV) is a risk factor in a subset of oropharyngeal cancer; however, the contribution of HPV in the malignancy of oral squamous cell carcinomas (OSCC) is not fully understood in Taiwanese. Herein, 61 patients with no risk factors and 117 patients with one or more risk factors were enrolled in this study. HPV16/18 infection rate in non-smokers, non-drinkers and non-betel quid chewers was higher than their counterparts. The development of HPV-infected cancer has been shown to be associated with interleukin-10 (IL-10) expression. To this end, IL-10 mRNA expression in OSCC tumors was evaluated by real-time RT-PCR. Data showed that HPV-positive patients had higher IL-10 mRNA levels than in HPV-negative patients. Kaplan-Meier and Cox-regression analysis indicated that the prognostic significance of IL-10 mRNA on overall survival and relapse free survival was only observed in HPV-positive OSCC, but not in HPV-negative OSCC. Mechanistically, the elevation of IL-10 by E6 was responsible for increased colony formation and migration capability in OSCC cells. Therefore, we suggest that IL-10 induced by E6 promotes cell growth and migration capability and consequent poor survival and relapse in HPV-positive OSCC.