Immunohistochemical expression of p16INK4A is predictice of HR-HPV infection in cervical low grade lesions

Department of Pathology, Regina Elena Cancer Institute, Rome, Italy.
Modern Pathology (Impact Factor: 6.19). 04/2006; 19(3):384-91. DOI: 10.1038/modpathol.3800551
Source: PubMed


The p16(INK4a) is a cyclin-dependent kinase inhibitor that decelerates the cell cycle by inactivating the cyclin-dependent kinases involved in the phosphorylation of the retinoblastoma protein (RB). Expression of E6 and E7 oncogenes of high-risk (HR) human papillomavirus (HPV), affecting the RB-p16 pathway, leads to p16 upregulation. Although it is widely reported that p16 is overexpressed in a high percentage of preneoplastic lesions and in almost all carcinomas of the uterine cervix, protein upregulation and its correlation with HPV infection in low-grade lesions is still being debated. In this study, we investigated in parallel, p16 expression and HPV infection in 100 cervical biopsies (17 normal tissues, 54 CIN1, 10 CIN2, 11 CIN3, eight invasive squamous cancers). Results obtained demonstrated that none of the 17 normal cervical tissues, evaluated by immunohistochemistry, presented p16 positivity whereas, starting from CIN1 (31%) to CIN2 (90%), CIN3 (100%) and carcinomas (100%), a constant and significant increase of protein overexpression (P<0.0001) was observed. In addition, p16 overexpression consistently showed elevated sensitivity (84%) and specificity (98%) in detecting HR-HPV infection with a high positive predictive value (97%) and negative predictive value (86%). Of interest, 93% of the p16-positive CIN1 were also HR-HPV infected. Our findings confirmed that p16 overexpression is associated to high-grade precancerous lesions and cervical carcinomas, and further demonstrated that immunohistochemical evaluation of p16 may be a useful biomarker in identifying HR-HPV-infected low-grade lesions.

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Available from: Isabella Sperduti, Apr 01, 2014
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    • "One study reveals that unlike non-progressive cases with negative CIN1, all CIN1 biopsies from patients who progressed to CIN 2-3 were positive for p16, 16 In this context, CIN1 lesions with positive p16 showed a markedly higher tendency to progress to CIN2-3, indicating that p16 may have a significant role in the evaluation of CIN1 lesions, excluding about half of the cases from an invasive clinical follow up. "
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    ABSTRACT: Background: Cervical intraepithelial neoplasia (CIN) is a premalignant lesion capable of progressing to cervical cancer. Despite the existing well-defined criteria, the histomorphologic diagnosis is subject to high rates of discordance among pathologists. The aim of this study was to evaluate Ki-67 (MIB-1), CK17 and p16 INK4a (p16) markers by immunohistochemical methods in differentiating CIN from benign cervical lesions. Methods: The present study reviewed and re-classified 77 cervical biopsies, originally diagnosed as 31 non-CIN, and 46 CIN, as 54 non-CIN, and 23 CIN based on at least two similar diagnoses. Immunostaining by Ki67, p16 and CK17 markers was performed on all cases and the results were compared with pervious and consensus diagnosis. Results: The overall agreement between pervious and consensus diagnosis was 67.5% (Kappa=0.39, P<0.001). The sensitivity and specificity of Ki67 immunostaining were 95.6% and 85.1% respectively, while for p16 the corresponding values were 91.3% and 98.1%. The overall agreement, for both p16 and Ki67, with consensus diagnosis were significant (P<0.001). The sensitivity and specificity of CK17 negative staining in CIN detection were 39.1% and 40.7% respectively. Conclusion: Ki67 and p16 markers are recommended as complementary tests for differentiating between dysplastic and non-dysplastic lesions. CK17 does not discriminate between immature metaplasia with and without dysplasia.
    Full-text · Article · Mar 2013 · Iranian Journal of Medical Sciences
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    • "Therefore, in addition to viral markers, such as E6/E7 mRNA or protein detection [9,10], cellular molecules related to cell cycle control, may be worth of investigation in cervical pathology. Several host proteins, such as p16 and Ki67 [11-13], have been studied, possibly representing novel biomarkers which are strictly linked to the host changes induced by HPV. Yet, none of them has been introduced in clinical guide lines so far, although p16 expression is currently used by many pathologists. "
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    ABSTRACT: Claspin is a nuclear protein involved in DNA replication and damage response and is a key mediator for the S-phase checkpoint. Claspin expression is significantly high in several human solid tumors. Furthermore, high levels of claspin have been found in cervical cancer cell lines. Nevertheless, no data are available regarding claspin expression in cervical tissues. In order to investigate whether claspin immunoreactivity is related to the lesion severity and High-Risk (HR) HPV infection, we analyzed claspin expression by immunohistochemistry in a series of cervical biopsies which represent the steps occurring during cervical carcinogenesis (normal tissues, Cervical Intraepithelial Neoplasias 1, 2 and 3, Squamous Cell Carcinomas). All patients also had a cervico-vaginal sample for HPV testing, collected immediately before the colposcopy-guided biopsy. The HR-HPV DNA detection was performed by the HR-HPV Hybrid Capture 2 test. HPV genotyping was performed using the Linear Array HPV Genotyping Test. Our results evidenced a constant and significant increase of the rate of claspin positivity from the normal tissues to carcinomas (pχ2trend < 0.0001). In fact, the normal tissues displayed either no or faint claspin immunoreactivity, whereas a moderate/high positivity was observed in 16% of the CIN1, 76% of the CIN2, 87.5% of the CIN3 and 93.3% of the cancers. Moreover, we found a statistically significant correlation between claspin expression and HR-HPV infection (pχ2 < 0.0001), irrespective of the genotype. Finally, we demonstrated the feasibility of claspin immunostaining in cervical cytology. Our findings indicate that in vivo claspin expression is significantly related to HR-HPV infection and lesion grade both in histological and cytological samples. Therefore, the analysis of claspin expression could be clinically relevant in the diagnosis of HPV-related cervical lesions, in particular when applied to cervico-vaginal cytology. Moreover, giving information on the proliferation rate of each lesion, claspin immunostaining may contribute to the evaluation of progression risk, thus being helpful in patient management. Nevertheless, only large prospective studies may clarify the true clinical usefulness of claspin expression in distinguishing lesions with different progression potential.
    Full-text · Article · Jun 2012 · Journal of Translational Medicine
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    • "In addition, in order to evaluate the role of β-HPV in neoplastic proliferation, the expression of two host genes, p16INK4a and Akt, were investigated. The expression pattern of p16INK4a in dysplastic squamous and glandular cervical cells in tissue sections and in cervical smears has been extensively investigated and linked [16,17] to anogenital α-HPV gene expression. The same α-HPVs are also able to interact with the Akt pathway [18]. "
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    ABSTRACT: 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.
    Full-text · Article · Nov 2011 · Journal of Experimental & Clinical Cancer Research
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