Prevalence of mucosal and cutaneous human papillomaviruses in different histologic subtypes of vulvar carcinoma.

Two independent pathways of vulvar carcinogenesis have currently been identified, one related to infection with mucosal human papillomaviruses (HPVs) and a second related to chronic inflammatory or autoimmune processes. The goal of the study was to examine a possible role of cutaneous HPVs from the beta genus in vulvar carcinogenesis and to evaluate the distribution of intratypic variants of HPV 16 in HPV 16-positive vulvar cancer. Consecutive cases of vulvar carcinoma were retrieved from the files and included the following histologic subtypes: keratinizing (n=21), basaloid (n=7), warty (n=1), mixed basaloid-warty (n=4), verrucous (n=4), keratoacanthoma (n=1), basal cell carcinoma (n=1). All tumors were microdissected and tested for 25 beta HPV types and 25 mucosal HPV types. Cases identified as positive for HPV 16 were further tested for intratypic variants. All cases were immunostained for p16INK4a. Beta HPVs were not detected in any of the tumor cases. Mucosal HPVs were detected in all but one basaloid/warty carcinomas; of these, nine cases (82%) were positive for HPV 16, including five European subtypes, one African subtype, one North American subtype and two indeterminate subtypes. Two of four verrucous carcinomas were positive for HPV 6. Mucosal HPVs were not detected in keratinizing carcinomas, keratoacanthoma and basal cell carcinoma. All cases of basaloid/warty carcinomas, but none of the remaining tumors, overexpressed p16INK4a protein. Our data do not support a role of beta HPVs in the pathogenesis of vulvar carcinoma. The study reaffirms the role of mucosal HPVs, in particular that of HPV 16, in the pathogenesis of basaloid and warty tumor subtypes. The HPV 16 intratypic variation showed correlation with patients' ethnic background. P16INK4a immunostaining seems to be a sensitive and specific marker of vulvar carcinomas positive for oncogenic mucosal HPVs.     

Alterations in the tumor suppressor gene p16(INK4A) are associated with aggressive behavior of penile carcinomas

Alterations in the p16/cyclinD1/Rb and ARF/Mdm2/p53 pathways are frequent events in the pathogenesis of squamous cell carcinomas. Different mechanisms of p16 regulation have been described for penile carcinomas so far. Therefore, expression of p16 and p53 was immunohistochemically detected with monoclonal antibodies in 52 primary invasive penile squamous cell carcinomas. The carcinomas were analyzed for allelic loss (LOH) in p16 ^INK4A and p53, as well as for mutations in the p16 ^INK4A and the p53 gene. In addition, we examined the promoter status of p16 ^INK4A by methylation-specific PCR. The presence of human papilloma virus (HPV) 6/11, HPV 16 and HPV 18 DNA was analyzed by PCR. Data were compared to clinical data. Concerning p16, 26 (50%) tumors showed positive immunohistochemistry, 32 (62%) tumors showed allelic loss and 22 tumors (42%) showed promoter hypermethylation. All tumors with negative p16 immunohistochemistry showed LOH near the p16 ^INK4A locus and/or hypermethylation of the p16 ^INK4A promoter. HPV 16 DNA was detected in 17 tumors, ten of them with positive p16 immunostaining. The remaining seven tumors with negative p16 staining showed allelic loss and/or promoter hypermethylation. Evidence of lymph node metastasis was significantly associated with negative p16 immunohistochemistry as well as with combined LOH and promoter hypermethylation (p = 0.003 and p = 0.018, respectively). Allelic loss around p53 was found in 22 tumors (42%), and seven mutations of the p53 gene could be demonstrated in our tumors. No correlations could be found between any p53 alteration and clinical parameters.     

Correlation of the HPV detection,protein expression and DNA content in cutaneous pre-invasive and invasive carcinoma among Croatian patients

Development of cutaneous carcinomas has been associated with HPV infection. There have been various reports on p16, p53 and pRb expression in cutaneous carcinomas and on its linkage to HPV status. Association of protein expression and HPV infection with DNA content is not clear. The aim of this study was to determine a possible correlation between HPV type, protein expression and DNA content in both pre-invasive and invasive squamous cell carcinoma, as well as differences between studied groups in these parameters. Sections of formalin fixed paraffin-embedded tumor tissue from 54 cases of Morbus Bowen (preinvasive cutaneous carcinoma) and 41 cases of invasive squamous cell carcinoma of the skin were subjected to HPV genotyping using Lipa (Line imuno probe assay), immunohistochemical staining for p16(INK4A), p53, pRb and prepared for flow cytometry DNA content analysis. Obtained data were analyzed in SPSS using Chi square test. Only p16 expression showed statistically significant differences in studied groups. Statistically significant correlations were found only in MB between parameters HPV-p53, p53-pRb and p53-p16. Our results suggest different virus-induced pathobiology pathways for different cutaneous carcinoma groups.     

膀胱移行细胞癌细胞周期调节相关基因表达与肿瘤生物学行为的关系

目的：探讨细胞周期调节相关基因p16INK4,p21WAF／CIP1,p53mlt在膀胱移行细胞癌中的表达与肿瘤增殖能力,病理分级及临床分期的关系。方法：应用免疫组织化学技术分析77例膀胱移行细胞癌组织p16INK4,p21WAF/CIP1,p53mlt基因的表达和增殖细胞核抗原（PCNA）表达情况,并与病理分级及临床分期之间进行综合分析。结果：p16INK4,p21WAF/CIP1,p53mlt在膀胱移行细胞癌中的表达及PCNA增殖指数与肿瘤的病理分级有关,与临床分期无关。p16,p21,p53阳性组与阴性组分别比较,其PCNA增殖数之间有差异性。多因素分析发现,p16INK4和p21WAF／CIP1阴性及p53mlt阳性组的PCNA值明显高于p16INK4和p21WAF／CIP1阳性及p53mlt阳性组,两者比较不同病理分级的阳性表达构成比亦有显著性差异。结论:联合检测p16INK4,p21WAF/CIP1,p53mlt基因的表达情况能充分反映膀胱移行细胞癌的增殖能力及生物学行为,对膀胱移行细胞癌患者的预后判断及治疗有指导意义。     

The retinoblastoma protein/p16 INK4A pathway but not p53 is disrupted by human papillomavirus in penile squamous cell carcinoma

Stankiewicz E, Prowse D M, Ktori E, Cuzick J, Ambroisine L, Zhang X, Kudahetti S, Watkin N, Corbishley C & Berney D M
(2011) Histopathology 58 , 433–439
The retinoblastoma protein/p16 ^INK4A pathway but not p53 is disrupted by human papillomavirus in penile squamous cell carcinoma Aims: The pathogenesis of penile squamous cell carcinoma (PSCC) is not well understood. Human papillomavirus (HPV) may be involved in carcinogenesis, but few studies have compared cell‐cycle protein expression in HPV positive and negative cancers. The aim was to determine the extent of HPV infection in different histological subtypes of PSCC and its impact on the expression of key cell‐cycle proteins: p53, p21, p16^INK4A and retinoblastoma (RB) protein. Methods and results: One hundred and forty‐eight PSCC samples were examined immunohistochemically for RB, p16^INK4A, p53 and p21 protein expression. One hundred and two cases were typed for HPV by PCR. HPV DNA was detected in 56% of tumours, with HPV16 present in 81%. Basaloid tumours were related strongly to HPV infection (10 of 13), while verrucous were not (three of 13). Fifty‐nine per cent (38 of 64) of usual type SCCs had HPV infection. RB protein correlated negatively (P < 0.0001) and p16^INK4A (P < 0.0001) and p21 (P = 0.0002) correlated positively with HPV infection. p53 did not correlate with HPV infection. Conclusions: HPV infection is present in more than half of penile cancers and it is responsible for RB pathway disruption. However, no link between HPV and p53 immunodetection was found. Only basaloid and half of usual‐type PSSCs correlate with HPV infection, confirming possible separate aetiologies for those tumours.     

Genetic and epigenetic alterations of 9p21 gene products in benign and malignant tumors of the head and neck

The multistep process of tumorigenesis has not been decoded to date, although numerous investigations into probable molecular changes have meanwhile been conducted. However, not only DNA changes or loss of alleles cause deregulation of gene function, but also epigenetic alterations (e.g. methylation) result in functional loss. The INK4a-ARF (CDKN2A) locus, located on chromosome 9p21, encodes two functionally distinct tumor suppressor genes, p14ARF and p16INK4a, which play active roles in the p53 and Rb tumor suppressive pathways. We therefore examined not only p16 and p14 proteins, but also alterations of the INK4a-ARF locus, including methylation and loss of heterozygosity in benign and malignant tumors of the head and neck (squamous cell carcinomas and pleomorphic adenomas). In benign pleomorphic adenomas, methylation of p14ARF was found in 1 out of 42 (2%) cases, whereas alterations of p16INK4a occurred in 12/42 (29%) pleomorphic adenomas. In HNSCC, methylation of p16INK4a occurred in 16 out of 50 (32%) carcinomas. P14ARF was found to be methylated in 8 out of 50 cases (16%). Our results demonstrate that alterations of the INK4a-ARF locus are frequent and important events not only in the carcinogenesis of malignant, but also in benign tumors.     

p16INK4a在宫颈细胞学鳞状上皮内瘤变中的意义

目的探讨p16^INK4a的表达在宫颈细胞学中鳞状上皮内瘤变中的意义及其与人乳头状瘤病毒（HPV）型别之间的关系。方法对88例经活检证实的液基细胞学标本[包括20例慢性宫颈炎、18例低度鳞状上皮内瘤变（LSIL）、34例高度鳞状上皮内瘤变（HSIL）及16例鳞状上皮细胞癌（SCC）],分别用免疫细胞化学（EnVision方法）检测其p16^INK4a的表达,并对所有标本用聚合酶链反应（PCR）方法检测HPV型别（包括HPV16、18、31、33、35、39、45、51、52、53、56、58、59、66、68、6、11、42、43及44型）。结果p16^INK4a在慢性宫颈炎组呈阴性,在LSIL、HSIL及SCC组的表达率分别为27．8％、100％及100％,LSIL、HSIL及SCC组p16^INK4a的表达均显著高于慢性宫颈炎组（P〈0．01）;p16^INK4a在高危型HPV感染组的表达率（96．4％）显著高于低危型HPV感染组（7．7％）,差异有统计学意义（t=4．32,P〈0．01）。结论p16^INK4a是一种敏感性较高,特异性较好的标记物,可以识别与高危型HPV有关的非典型鳞状上皮细胞。     

P16 overexpression and human papillomavirus infection in small cell carcinoma of the uterine cervix

Carcinogenesis of cervical cancer has been investigated, and p16(INK4a) overexpression in squamous cell carcinoma of the cervix has been reported as a result of infection by human papillomavirus (HPV) (eg, HPV 16), and the consequence of the retinoblastoma (Rb) protein inactivation by HPV E7 protein. However, to our knowledge, there have been no studies on the relation between p16(INK4a) overexpression associated with HPV and small cell carcinoma of the cervix, which behaves more aggressively clinically than squamous cell carcinoma. The purpose of this study was to determine whether p16(INK4a) is overexpressed in small cell carcinoma, and if p16(INK4a) is overexpressed, the types of HPV that are related to this cancer. We reviewed 10 cases of small cell carcinoma and examined them for p16(INK4a) overexpression by immunohistochemistry. We also performed HPV typing with polymerase chain reaction (PCR)-sequencing analysis and in situ hybridization and found that p16(INK4a) was overexpressed in every case. PCR-sequencing analyses revealed that all cases were HPV-positive and that 9 cases were positive for HPV 18. Five of the 9 cases positive for HPV 18 were also positive by in situ hybridization and yielded a punctate signal, considered to represent the integrated form. In conclusion, p16(INK4a) was overexpressed and HPV 18 was frequently detected in an integrated form in small cell carcinoma. Therefore, inactivation of Rb protein by HPV 18 E7 protein may be associated with carcinogenesis of small cell carcinoma the same as inactivation of Rb protein by HPV 16 E7 protein is associated with carcinogenesis of squamous cell carcinoma.     

Detection of HPV-DNA, p53 alterations, and methylation in penile squamous cell carcinoma in Japanese men

Penile carcinoma is a rare disease, accordingly there are few studies on molecular changes, and these results also vary greatly. A total of 26 penile squamous cell carcinomas in Japanese men were studied with respect to HPV, p53 alterations, and methylation of gene promoter region. HPV-DNA was detected in three of 26 patients (11.5%). Overexpression of p53 was observed in 13 of 26 patients (50%), and p53 gene mutations were detected in four of 26 patients (15.4%). The frequency of methylation was as follows: DAPK , 26.9% (7/26); FHIT , 88.4% (23/26); MGMT , 19.2% (5/26); p14 , 3.8% (1/26); p16 , 23.1% (6/26); RAR -β, 23.1% (6/26); RASSF1A , 11.5% (3/26); and RUNX3 , 42.3% (11/26). As for correlation between HPV and p53 alterations, and methylation status, mutations of the p53 gene were detected only in HPV-negative patients, and methylation was more frequently found in HPV-negative than in HPV-positive patients. The present results suggest that the majority of penile squamous cell carcinomas in Japanese men are unrelated to HPV, and gene alterations accumulate more frequently in HPV-unrelated penile carcinomas.     

INK4a-ARF alterations and p53 mutations in primary and consecutive squamous cell carcinoma of the head and neck

BACKGROUND: The INK4a-ARF (CDKN2A) locus, located on chromosome 9p21, encodes two functionally distinct tumor suppressor genes, p14(ARF) and p16(INK4a), that play active roles in the p53 and Rb tumor suppressive pathways, respectively. We analyzed the alterations of p14(ARF), p16(INK4a) and p53 to study the contribution of each pathway in tumorigenesis of 29 patients with primary and consecutive (second primary) squamous cell carcinoma of the head and neck (HNSCC), with a total of 68 carcinomas. METHODS: After microdissection, the DNA of 29 primary and 39 consecutive squamous cell carcinomas was analyzed for INK4a-ARF inactivation and p53 mutation by means of DNA sequence analysis, methylation-specific polymerase chain reaction (MSP), restriction-enzyme-related polymerase chain reaction (RE-PCR), multiplex RT-PCR and immunohistochemistry. In addition, microdeletions of p14(ARF) and p16(INK4a) were assessed using differential PCR. RESULTS: Altogether inactivation (methylation, loss of heterozygosity and mutation of exon 1beta) of p14(ARF) was found in 29 of all 68 (43%) carcinomas, with a significant difference in primary [8 of 29 (28%)] relative to second primary carcinomas [21 of 39 (54%)]. Methylation of p16(INK4a) occurred in 22 of 68 (32%) carcinomas with an even distribution among primary and consecutive tumors. Only two (secondary) carcinomas showed simultaneous promoter methylation of p14(ARF) and p16 (INK4a). Mutations of p53 were found in 32 of 68 HNSCCs (44%), evenly distributed among primary and recurrent carcinomas. p14(ARF) alterations showed no relationship to p53 mutations. CONCLUSIONS: Our data indicate that the INK4a-ARF-/p53 pathway was disrupted in 58 of 68 (84%) primary and recurrent tumors, either by p53 mutations or by INK4a-ARF inactivation. p14(ARF) methylation occurred independently of p16(INK4a) alterations and showed no correlation to p53 mutations. The significantly higher rate of p14(ARF) alterations in recurrent (respective second primary) carcinomas suggests a further acquired genetic aberration during the development of the recurrent carcinomas.     

p53 Mutation in carcinomas arising in ovarian cystic teratomas

Carcinomas arising in mature cystic teratomas of the ovaries from nine women were examined for the presence of p53 mutations. The nine tumors comprised six squamous cell carcinomas, one squamous cell carcinoma in situ , one undifferentiated small cell carcinoma, and one muco-epidermoid carcinoma. Abnormal nuclear accumulation of the p53 protein was obsenred in four of the tumors. Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissue blocks and subjected to polymerase chain reaction (PCR) for specific amplification of the p53 gene exons 5–8, followed by direct chemiluminescence sequencing analysis. A frameshift mutation in exon 8 (codon 278, CCT > del T; stop at codon 344) was detected in one poorly differentiated squamous cell carcinoma. The samples were also evaluated for the possible association of 'benign' and 'malignant' types of human papillomavirus (HPV) by PCR using universal primer sets. None of the samples contained detectable HPV genome. These data suggest that p53 mutations are relatively uncommon in secondary carcinomas developing in ovarian. dermoid cysts, although the number of samples studied was admittedly small.     

Pathways of vulvar intraepithelial neoplasia and squamous cell carcinoma

Vulvar squamous cell carcinoma (VSCC) accounts for >90% of the malignant tumours of the vulva. Most VSCCs originate in intraepithelial lesions, named vulvar intraepithelial neoplasia (VIN), that precede the development of VSCC by a variable period of time. Strong evidence has accumulated showing that there are two different aetiopathogenic pathways for the development of VSCC and VIN, one associated with infection by human papillomavirus (HPV), and a second independent of HPV infection. These two different types of VSCC have different epidemiological, pathological and clinical characteristics, and should therefore be considered as two separate entities. Histologically, HPV‐associated VSCCs are of the basaloid or warty type, and arise from VIN of the usual type. Inactivation of p53 and the retinoblastoma tumour suppressor gene product by the viral gene products E6 and E7 is involved in the process of malignant transformation. HPV‐independent VSCCs are histologically keratinizing, are associated with differentiated VIN and lichen sclerosus, and frequently show mutations of p53. p16^INK4a and p53 immunostaining can be useful for classifying VSCC into HPV‐associated or HPV‐independent. Although large, multicentre studies are needed to definitively assess the involvement of HPV in the prognosis of VSCC, most studies have not found clear differences in survival between HPV‐associated and HPV‐independent tumours.     

Aberrant methylation of p14(ARF), p15(INK4b) and p16(INK4a) genes and location of the primary site in pulmonary squamous cell carcinoma

Aberrant methylation of cytosines in CpG islands of the promoter regions of tumor suppressor genes is found in human tumors as a common mechanism of gene silencing. We investigated the methylation status of the chromosome 9p21 gene cluster (p14(ARF), p15(INK4b) and p16(INK4a) genes) by methylation-specific polymerase chain reaction in 20 central and 40 peripheral types of pulmonary squamous cell carcinoma (SqCC) in order to determine the differences between the pathogeneses of the central and peripheral types of SqCC. The frequencies of methylation were 30% for the p14(ARF) gene, 20% for the p15(INK4b) gene and 40% for the p16(INK4a) gene in the central type and 25% for the p14(ARF) gene, 10% for the p15(INK4b) gene and 38% for the p16(INK4a) gene in the peripheral type. Cases in which there was methylation of the p16(INK4a) gene had a higher smoking index in the peripheral type (P = 0.007). This trend was not detected in the central type. Methylation of two or three genes was observed in 55% of methylation in at least one gene of the central type but in only 17% of the peripheral type. This overlap methylation of the chromosome 9p21 gene cluster was found more frequently in the central type (P = 0.02). These findings suggest one of the epigenetic differences between the central and peripheral types of SqCC.     

p53 gene mutations and MDM2 amplification are uncommon in primary carcinomas of the uterine cervix.

The p53 gene is the most frequently altered gene known thus far in a wide variety of human cancers. Inactivation of p53, either through mutation or through interaction with the human papillomavirus (HPV) E6 oncoprotein, is a characteristic feature of all cervical carcinoma cell lines that have been studied. These findings suggest that p53 inactivation is required for cervical carcinoma development and that HPV infection and p53 mutation may be mutually exclusive. We have studied the p53 gene in 35 primary cervical carcinomas. DNA sequence and single strand conformational polymorphism analyses were used to evaluate p53 in 27 squamous carcinomas (25 HPV-positive) and eight adenocarcinomas (four HPV-positive). A missense mutation of p53 was observed in one HPV 16-positive squamous carcinoma, demonstrating that p53 mutations can occur in combination with HPV infection. The HPV-negative tumors all lacked p53 gene mutations. The absence of p53 mutations in HPV-negative cases prompted an assessment of tumors for MDM2 gene amplification. The MDM2 gene encodes a p53 binding protein and has been found to be amplified in some human tumors lacking p53 mutations. MDM2 amplification was not identified in any of the tumors we examined, including four HPV-negative cases. Our findings show that HPV infection and p53 gene mutation are not mutually exclusive and suggest that many HPV-negative carcinomas may arise via a pathway independent of p53 inactivation.     

HPV DNA and p53 alterations in oropharyngeal carcinomas

We have examined a series of 37 oropharyngeal squamous cell carcinomas for the presence of HPV \611, 16, and 18 DNA by polymerase chain reaction (PCR)/Southern blotting and for p53 alterations by immunohistochemistry and mutation screening with temperature gradient gel electrophoresis (TGGE). HPV sequences were found in a total of 26 of 37 cancers (70.3%), most frequently HPV 16 (\2037) followed by HPV 18 (\1137). Double infections with HPV 16 and 18 were present in 5 tumours. p53 accumulation was detectable immunohistochemically in 21 of 37 carcinomas (56.8%). There were remarkable differences in the distribution of immunoreactive tumour cells in relation to the tumour grade. A mutation screening for p53 by TGGE, directed to the amplified exons 5–8, revealed p53 mutations in 14 of 37 carcinomas (37.8%). Mutations in two different exons were present in 3 tumours, 11 tumours being hit once. Exon 7 was mutated in 6 carcinomas, exons 5 and 8 in 4 cases, and exon 6 in 3 cases. When grouping the tumours with p53 mutation according to their HPV state, HPV-positive cases showed slightly more mutations (\1126) than HPV-negative cases (\311). Only 5 of 37 carcinomas (13.5%) contained neither HPV DNA nor p53 alterations. Our results indicate that high-risk HPV and p53 mutations frequently coexist in oropharyngeal carcinomas, in contrast to genital tumours, notably carcinomas of the cervix uteri. This may reflect different pathways in carcinogenesis in squamous cell epithelium from different sites.     

Squamous cell carcinomas arising from adnexal ductal cysts.

Malignant tumors arising from adnexal cysts are rare. We report 2 cases of squamous cell carcinomas that developed within cystic structures arising from adnexal ducts. An in situ hybridization technique for human papillomaviruses (HPV)-6/11, -16, -18, and -31, and immunohistochemical staining for p53 were performed. Both tumors showed focal expression of HPV-16 within areas showing squamoid changes and diffuse expression of p53 within the areas of invasive squamous cell carcinoma. Although nuclear staining for HPV has been identified in tumors of adnexal origin, to our knowledge these are the first cases in which a highly oncogenic HPV subtype, HPV-16, has been identified within squamous cell carcinomas arising from adnexal ductal structures. These cases may help explain primary cutaneous squamous cell carcinomas with no epidermal origin.     

Expression of p16, Rb, and p53 proteins in squamous cell carcinomas of the anorectal region harboring human papillomavirus DNA.

Human papillomavirus (HPV) has been implicated as an etiologic agent for the development of squamous cell carcinoma of the anorectal region. It has been shown that the HPV E6 and E7 oncoproteins are able to inactivate the tumor suppressor functions of p53 and Rb. In cervical and head and neck cancers, HPV infection is also associated with an overexpression of p16, a cyclin-dependent kinase inhibitor. The expression of these cell cycle regulators in squamous cell carcinomas of the anorectal region has not been well studied. In the current study, 29 cases of squamous cell carcinoma of the anorectal region were immunohistochemically examined for the expression of p16, Rb, and p53 proteins. Tumor cell DNA was also extracted from paraffin blocks and subjected to broad-spectrum HPV DNA testing and typing. The results show that the tumor cells exhibited a strong and diffuse nuclear stain (with some cytoplasmic positivity) for p16 in all 29 cases (100%). The adjacent nonneoplastic squamous epithelium or colonic mucosa, in contrast, was completely negative. Loss of Rb nuclear staining in tumor cells was observed in 20 cases (69%). The p53 protein was essentially undetectable, with only 6 cases containing <10% positive cells. HPV DNA was detected in every case (100%), with 25 cases (86%) harboring Type 16. In addition, almost identical results were obtained in 12 HPV-positive squamous cell carcinomas of the upper aerodigestive tract. This was in marked contrast to those of HPV-negative tumors, where positive p16 staining and loss of Rb expression were seen in only 2/21 (10%) and 1/21 (5%) cases, respectively. These observations indicate that overexpression of p16 and loss of Rb nuclear staining are commonly associated with high-risk HPV infection, which may serve as useful surrogate biomarkers for identifying squamous cell carcinomas harboring HPV DNA.