p16INK4A overexpression and HPV infection in uterine cervix adenocarcinoma

Human papillomaviruses (HPVs) are causally involved in the genesis of cervical carcinomas and their precursors, and there is a strong relationship between the cyclin-dependant kinase inhibitor p16^INK4A and HPV infection. This study was carried out to assess the correlations between p16^INK4A expression as an early biomarker of the endocervical adenocarcinoma and HPV infection. p16^INK4A expression and HPV typing were performed on 46 samples including 5 normal endocervix, 9 benign lesions of the endocervix, 25 endocervical adenocarcinomas, and 7 endometrioid adenocarcinomas of the uterine corpus. A semiquantification of the p16^INK4A immunostaining was realized (using both the staining intensity and the percentage of positive cells) and was graded from 0 to 15. All of the 25 endocervical adenocarcinomas overexpressed p16^INK4A; the adjacent epithelium and the connective tissue were strictly negative. No p16^INK4A was detected in nine benign endocervical lesions and in five normal endocervix. Few endometrioid adenocarcinomas of the uterine corpus that infiltrate the endocervix exhibited a low immunoreactivity (score 0/15 or 1/15). This pattern of expression is significantly associated with HPV infection (p<10 ⁻³), mainly high-risk HPV types (p=0.02). Our results suggest that p16^INK4A is a putative molecular biomarker that consistently discriminates uterine cervix adenocarcinomas from benign lesions and from endometrioid adenocarcinomas of the uterine corpus .     

In situ detection of SOCS and cytokine expression in the uterine cervix from HIV/HPV coinfected women

The purpose of this study was to look for associations between a newly described class of suppressors of cytokine signaling (SSI/SOCS) and cytokine expression in the uterine cervix from HIV/HPV coinfected women. We examined the pro-inflammatory cytokines TNF-alpha and IL-6 since their expressions are linked and responsible for many aspects of both localized and systemic inflammatory responses. Further, expression of SSI/SOCS has been implicated in the negative feedback regulation of cytokine receptor signaling. PCR-amplified HIV-1 cDNA was noted mainly in the stroma, showing a perivascular distribution, and most of the infected cells colabeled with the macrophage marker CD68. The distribution of IL-6 and TNF-alpha was in the same area to HIV-1 and much greater than normal cervices from women with no evidence of viral infection. SOCS/SSI-1 and -3 mRNA positive cells in the uterine cervix were commonly detected in these noninfected cervical tissues; however, very few cells that contained SOCS were evident in areas where HIV-1, TNF-alpha, and IL-6 expressing cells were found. This suggests that viral-related suppression of SOCS/SSI-1-3 expression may be a factor in the marked local enhancement of TNF-alpha and IL-6 production which, in turn, may help facilitate viral spread; however, further studies should be done in order to elucidate the exact mechanisms of SOCS in the cervix.     

Down-regulation of p27Kip1 expression is correlated with increased cell proliferation but not expression of p21waf1 and p53, and human papillomavirus infection in benign and malignant tumours of sinonasal regions

AIMS: Although p27Kip1(p27) is a cyclin-dependent kinase inhibitor and a contribution to tumorigenesis has been hypothesized, the possible role in tumours arising in the nasal and paranasal sinus regions is still unknown. METHODS AND RESULTS: Seventy-six sinonasal tumours, including 28 inverted papillomas (IPs) and 48 squamous cell carcinomas (SCCs), were immunohistochemically investigated, along with 46 exophytic papillomas (EPs) of upper respiratory tract and 34 samples of normal paranasal sinus epithelium. The results were also compared with expression of p21WAF1 (p21) and p53, cell proliferation assessed in terms of Ki67 labelling indices (LIs), and human papillomavirus (HPV) infection. The average p27 scores decreased from normal through to malignant lesions, while Ki67 LI scores showed a stepwise increase, the inverse correlation between scores for all categories being significant (r = - 0.639, P < 0. 0001). In the SCCs, p27 expression was significantly higher in keratinizing than nonkeratinizing type tumours (P < 0.05), while there was no association with p21 and p53 expression. Although HPV DNAs for type 16 and 18 were detected in two (7.4%) of 27 EPs, six (35.8%) of 28 IPs, and nine (28.1%) of 32 SCCs, no relation with p27 scores was evident. CONCLUSION: Loss of p27 expression correlates with increased cell proliferation in sinonasal tumours. Moreover, the expression appears to be associated with keratinization in SCCs of the paranasal sinus. These findings indicate that p27 expression may be a useful marker for the dysregulation of cell kinetics in these tumours.     

子宫颈病变中p16INK4A 蛋白表达及其与HPV16/18感染的关系

目的 探讨p16INK4A 蛋白在子宫颈鳞癌(SCC)和子宫颈上皮内肿瘤(CIN)中的表达及其与HPV16/18感染的关系.方法 用原位杂交法检测HPV16/18在25例子宫颈癌、45例CIN及10例慢性子宫颈炎中的表达,同时用免疫组化EliVision法检测p16INK4A 蛋白的表达.结果 (1)与慢性子宫颈炎相比,CIN Ⅱ级、CIN Ⅲ级、浸润癌HPV16/18杂交信号阳性率显著增高(P<0.01);(2)子宫颈鳞癌组织、CIN Ⅰ级、CIN Ⅱ级、Ⅲ级及慢性子官颈炎标本中p16INK4A 蛋白阳性率分别为100.0%、20.0%、46.7%、100.0%和10.0%;(3)在子宫颈鳞癌及CIN HPV16/18感染的标本中p16INK4A 蛋白表达均是阳性.结论 子宫颈鳞癌的形成与HPV感染、p16INK4A 蛋白过表达是呈正相关关系,p16INK4A蛋白可能作为子宫颈鳞癌及CIN的标志物,对子宫颈癌筛查和预防有重要意义.     

TP53 alterations in relation to the cell cycle-associated proteins p21, cyclin D1, CDK4, RB,MDM2, and EGFR in cancers of the uterine corpus

In the present study, TP53 alterations have been analysed and compared with the expression of the proteins p21, cyclin D1, cdk4, RB, EGFR, and MDM2 in 53 cancers of the uterine corpus. TP53 gene mutations analysed by CDGE/DGGE and direct sequencing showed a TP53 gene mutation in 18 per cent of the cases. TP53 gene mutations were not significantly related to overexpression or down-regulation of any of the proteins. Immunohistochemically, there was an increased protein level of TP53 in 77 per cent, p21 in 36 per cent, cyclin D1 in 45 per cent, cdk4 in 77 per cent, EGFR in 8 per cent, and MDM2 in 32 per cent of the cases. Expression of RB protein was normal in all cancers. Significant association of protein expression was seen between TP53 and MDM2 (p = 0·005) and p21 and MDM2 (p = 0·001). Furthermore, there may be an association between TP53 and p21 (p = 0·038) and cyclin D1 and cdk4 (p = 0·045). The results revealed increased levels of TP53 protein in all MDM2-positive cases that did not show TP53 mutations, indicating TP53 protein stabilization and inactivation by complex formation with MDM2. In summary, the high number of cases showing an increased level of TP53 and cdk4 proteins suggests that these proteins play an important role in the neoplastic process in cancers of the uterine corpus. Copyright © 1999 John Wiley & Sons, Ltd.     

The presence of high-risk HPV combined with specific p53 and p16INK4a expression patterns points to high-risk HPV as the main causative agent for adenocarcinoma in situ and adenocarcinoma of the cervix

Adenocarcinoma in situ (ACIS) and adenocarcinoma (AdCA) of the cervix are frequently missed in population-based screening programmes. Adding high-risk HPV (hrHPV) testing to cervical cancer screening might improve the detection rate of ACIS and AdCA. Since the exact proportion of AdCAs of the cervix that can be attributed to hrHPV infection is still a matter of debate, a comprehensive study was performed of hrHPV presence in ACIS and AdCA of the cervix. Archival formalin-fixed specimens of indisputable ACIS (n=65) and AdCA (n=77) of the cervix were tested for hrHPV DNA by GP5+/6+ PCR-enzyme immunoassay (EIA) and type-specific E7 PCR for 14 hrHPV types. Further immunostaining for p16INK4A and p53 was performed to assess alternative pathways of carcinogenesis potentially unrelated to HPV. hrHPV DNA was found in all (100%) ACISs and 72 (94%) cervical AdCAs, whereas none of 20 endometrial AdCAs scored hrHPV-positive. HPV 18 was most prevalent and found as single or multiple infection in 68% of ACISs and 55% of cervical AdCAs. Diffuse immunostaining for p16INK4a, a potential marker of hrHPV E7 function, was significantly more frequent in hrHPV-positive cervical AdCAs (19/20; 95%) than in those without hrHPV (1/5; 20%; p<0.001). Immunostaining for p53, pointing to stabilized wild-type or mutant p53 protein, was significantly more frequent in hrHPV cervical AdCAs negative for hrHPV (p=0.01). No difference in p16INK4a and p53 immunostaining was found between hrHPV-negative cervical AdCAs and endometrial AdCAs. Hence, only a minority of cervical AdCAs displayed absence of HPV DNA and immunostaining profiles suggestive of an aetiology independent of HPV. Since all ACISs and nearly all cervical AdCAs were hrHPV-positive, the incorporation of hrHPV testing in cervical cancer screening programmes is likely to decrease markedly the incidence of cervical AdCA.