Molecular characterization of adenocarcinoma of the cervix

A systematic review and meta-analysis of the prevalence of therapeutic targets in cervical cancer

Cervical Cancer (CC) is a significantly prevalent disease in developing countries. Currently, targeted therapies are not a primary standard of care in CC. This information could be crucial for developing directed therapies and patient screening for biomarkers that would allow personalised treatment of CC. This systematic review aimed to estimate the prevalence of potential therapeutic targets such as the epidermal growth factor receptor (EGFR) and the PI3K/Akt/mTOR and Ras/Raf/MAPK pathways in patients with CC, identified through genomic and non-genomic testing. Studies were identified through an ad-hoc search strategy from the available on MEDLINE (Ovid), CENTRAL, LILACS, SCOPUS, through the Clinical Trial registry on Clinicaltrials.gov, International Clinical Trials Registry Platform, RENIS (Argentine National Registry of Health Research) and grey literature sources. We included 74 studies which represented a total pool of 7,862 participants. Forty-five studies informed mutations of EGFR, with a combined positivity rate of 53% (95%CI: 45%-60%; I2 = 95%). Twenty studies informed the presence of mutations in PIK3CA with a combined positivity rate of 30% (95%CI: 21%-39%; I2 = 96%). Twenty-three studies reported a mutation in Ras, with a combined positivity rate of 14% (95%CI: 8%-21%; I2 = 95%). Raf mutations were informed in six studies. Six studies informed the presence of Akt mutations, two studies informed mTOR mutations and only one study reported mutations of MAPK. The most frequently described therapeutic targets were EGFR, and the PIK3CA and Ras pathways, though inconsistency in positivity rates was significant. Our study did not allow the identification of any specific clinical characteristics that might explain the observed heterogeneity. Despite the overall good quality of the included studies, the applicability of these results to patients' general population with CC is still unclear.

[Use of HPV virologic test for atypical glandular cells in Alsace between 2014 and 2016]

OBJECTIVES

The new recommendations by the National Institute of Cancer (January 2017) recommend the use of a complementary human papillomavirus (HPV) virologic test during the diagnosis of atypical glandular cells in pap smear. The aim of this study was the performance analysis of the HPV virologic test for the detection of significant histological cervical abnormalities (CIN2 or more) in case of atypical glandular cells before the new recommendations were published.

METHODS

We performed a descriptive and retrospective cohort study in Alsace between January 2014 and December 2016. We have included, from the EVE-association database, the patients with atypical glandular cells in pap smear.

RESULTS

In total, 1074 patients had a pap smear with atypical glandular cells ; 0.18% of total pap smears. This study included 152 patients who had a HPV test. We observed 6 cases of CIN2 (3.9%) and 12 cases of CIN3 (7.9%). No in situ adenocarcinoma nor invasive carcinoma were detected. The sensitivity of the HPV test was 88.9% (95% CI: [0.65; 0.99]), the specificity was 65.9% (95% CI: [0.55; 0.76]), the positive predictive value was 34% (95% CI: [0.21; 0.49]) and the negative predictive value was 96.8% (95% CI: [0.89; 0.99]).

CONCLUSION

The detection of HPV in atypical glandular cells seems to be powerful with an excellent negative predictive value but, because of moderate sensitivity and due to the risk of histologic lesion progression, the current recommendations should to be applied with care.

Absence of high-risk human papillomavirus (HPV) detection in endocervical adenocarcinoma with gastric morphology and phenotype

A subset of endocervical-type mucinous adenocarcinomas (ACs) of the uterine cervix exhibit a gastric phenotype and morphology, as reported in cases of minimal deviation AC in which the presence of human papillomavirus (HPV) has been rarely detected. To investigate the HPV-independent pathway of carcinogenesis in cases of gastric-type AC, we investigated the common high-risk HPV (hr-HPV) status in 52 nonsquamous cell carcinomas, using a PCR-based typing method and immunohistochemistry of p16INK4a (a cyclin-dependent kinase inhibitor that is overexpressed in both cancerous and precancerous cervical tissue, making it an ideal biomarker for cervical cancer cases). Using novel morphological criteria, seven of 52 (13.5%) carcinomas were designated as gastric-type ACs, all of which were negative for both hr-HPV DNA and p16INK4a. Nongastric-type ACs were frequently positive for both hr-HPV DNA (90%, 28/31) and p16INK4a (94%, 29/31) with adenosquamous and neuroendocrine carcinomas demonstrating the presence of hr-HPV DNA in 86% (6/7) and 83% (5/6) of cases, respectively. In these two types of carcinoma, 86% (6/7) and 100% (6/6) were positive for p16INK4a, respectively. Our data suggests that gastric-type AC appears to represent an oncogenic hr-HPV-independent neoplasm and therefore is a potential pitfall of HPV DNA testing and vaccination.

Prevalence, viral load, and physical status of HPV 16 and 18 in cervical adenosquamous carcinoma

Adenosquamous carcinoma of the uterine cervix is a rare mixture of malignant squamous and glandular epithelial elements and accounts for approximately 10% of cervical carcinomas. The aims of the present study were to evaluate the prevalence, physical status, and viral load of HPV 16 and 18 in adenosquamous carcinoma. Formalin-fixed paraffin-embedded tissue samples from 20 cases of histologically diagnosed adenosquamous carcinoma were examined. The squamous and glandular components were separately microdissected and analyzed for their HPV DNA subtype, viral load, and physical status using real-time polymerase chain reaction (PCR). The percentages of HPV 16- and 18-positive cases among all the HPV-positive cases were 36.8% (7/19) and 57.9% (11/19) in the squamous epithelial elements and 33.3% (6/18) and 61.1% (11/18) in the glandular elements, respectively. PCR analysis with E2 primers revealed that seven of eleven (63.6%) HPV 18-positive cases had the pure integrated form in both elements. The mean HPV 16 DNA copy numbers/cell was 7.22 in the squamous elements and 1.33 in the glandular elements (p=0.04) while the corresponding mean HPV 18 DNA copy numbers/cell was 1.50 and 0.89, respectively. The prevalence of HPV 18 in adenosquamous carcinoma was high and many HPV 18-positive cases were the pure integrated form resulting in very low copy numbers/cell. It is possible that more aggressive transformation with early integration of HPV 18 results in cases with greater chromosomal instabilities, higher growth rates, and rapid progression.

Oncosuppressor proteins of fragile sites are reduced in cervical cancer

FHIT and WWOX are tumor suppressor genes that span the common fragile sites FRA3B and FRA16D, respectively. To analyze possible synergisms among these genes in cervical cancer progression, we considered 159 cervical intraepithelial neoplasias, and 58 invasive squamous cell carcinomas of the uterine cervix. All cases were previously selected as high risk HPV. FHIT and WWOX proteins were examined by immunohistochemistry and their expression was inversely correlated with precancerous vs. invasive lesions. Statistics among biological markers indicated an association between FHIT and WWOX. Protein expression of these two genes was also absent or reduced in cancer cell lines. Thus, WWOX may be considered as a novel important genetic marker in cervical cancer and the association between the altered expression of FHIT and WWOX may be a critical event in the progression of this neoplasia.

The human papillomavirus type 18 E6 oncoprotein induces Vascular Endothelial Growth Factor 121 (VEGF121) transcription from the promoter through a p53-independent mechanism

Altered angiogenic response is associated with high-grade cervical dysplasia and with invasive squamous carcinoma of the cervix. Vascular Endothelial Growth Factor (VEGF) is one of the most potent inducers of angiogenesis and is up-regulated in carcinoma of the cervix. Infection by high-risk human papillomavirus and persistent expression of viral oncogene E6 are etiologically linked to the development of cervical cancer. E6 is able to immortalize cells and induce malignant transformation by inactivating p53. In cervical cancer, regulation of VEGF expression is poorly described. Thus, we investigated whether E6 oncoprotein could regulate VEGF expression in HPV18-positive cervical cancer-derived HeLa cells harboring a wild-type p53. The alternative splicing of vegf mRNA renders three major isoforms of 121, 165 and 189 amino-acids in humans. We have designed isoform specific real time QRT-PCR assays to quantitate vegf transcripts and VEGF121 was the predominant isoform. Silencing HPV18 E6 mRNA with specific siRNA reduced VEGF121 expression by at least 50% whereas silencing of p53 did not alter its expression. Treatment with cycloheximide did not inhibit E6-induced VEGF121 expression. Collectively, these results suggest that HPV18 E6 oncoprotein contributes to tumor angiogenesis by inducing VEGF transcription from the promoter in a p53-independent manner.

Role of human papillomavirus in the etiology of head and neck cancer

Head and neck cancer is the world's sixth most common cancer, but despite advances in treatment, there has been no significant decline in the mortality rate. In recent years, there has been mounting epidemiologic and experimental evidence of a role for human papillomavirus (HPV) as the etiologic agent of a subset of head and neck cancers. The association is strongest for oropharyngeal cancers, especially those of the tonsil. HPV 16 is invariably the predominant type. HPV-positive cancers have been shown to be biologically distinct, clustering among nonsmokers and light drinkers, and have been associated with a favorable prognosis. This review examines the current findings of HPV in head and neck cancers and discusses implications for developing new treatments.

Inverse correlation between RASSF1A hypermethylation, KRAS and BRAF mutations in cervical adenocarcinoma

OBJECTIVE

Although the incidence of cervical adenocarcinoma is increasing, few genetic and epigenetic changes in its progression have been described. We hypothesized that RASSF1A methylation and KRAS and BRAF mutations may play an important role in cervical adenocarcinoma.

METHODS

Archival primary carcinoma tissues (n=258) in uterine cervix consisting cervical adenocarcinomas (n=115) and squamous cell carcinomas (n=143) were evaluated for activating mutations of BRAF and KRAS and promoter hypermethylation of RASSF1A using methylation specific PCR and specific sequence analysis. HPV E7 Type-specific PCR was used for HPV-16 and -18 status.

RESULTS

KRAS mutations were found in 16 adenocarcinomas (13.9%), while BRAF mutations were found in 5 (4.3%). RASSF1A methylation was found in 27 adenocarcinomas (23.5%) and inversely correlated with KRAS and/or BRAF mutation (p=0.002) in cervical adenocarcinoma. In cervical squamous cell carcinomas, KRAS mutations were detected only in 1 (0.7%) cases and RASSF1A hypermethylation was detected in 2 (1.4%). The frequency of KRAS mutation and RASSF1A methylation were significantly different between adenocarcinomas (P<0.001) and squamous cell carcinomas (P<0.001). Neither KRAS mutation nor RASSF1A methylation were associated with HPV status. RASSF1A hypermethylation and KRAS mutations and BRAF mutations are inversely correlated and play an important role in the development of adenocarcinomas.

CONCLUSIONS

These results are suggesting that these two histological types of cervical cancer arise through different molecular pathways in tumor development. Different genetic/epigenetic alterations may explain the possible different therapeutic responsiveness between adenocarcinoma and squamous cell carcinoma of uterine cervix seen in clinic.

The significance of prohibitin and c-Met/hepatocyte growth factor receptor in the progression of cervical adenocarcinoma

To examine the importance of prohibitin 1 and c-Met/hepatocyte growth factor receptor (HGFR) expression in human cervical adenocarcinomas, 85 patients (69 with invasive adenocarcinoma [ACA] and 16 with adenocarcinoma in situ [AIS]) were studied using immunohistochemistry. High prohibitin 1 expression was found in 51 (73.9%) of the 69 ACAs and 11 (68.7%) of the 16 AIS lesions. Prohibitin 1 overexpression was significantly higher in ACA and AIS than in adjacent nonneoplastic glandular epithelium (P < .001 for both comparisons). Prohibitin 1 expression was also positively related to tumor size (P = .019) or parametrial involvement (P = .027) in ACA. c-Met was expressed in 21 ACAs (30.4%) and was positively correlated with the Fédération Internationale de Gynécologie et d'Obstétrique (International Federation of Gynecology and Obstetrics) stage classification (P = .007) or nodal metastasis (P = .047). Nodal metastasis (P = .028) and c-Met expression (P = .022) were independent predictors for the overall survival of patients in multivariate analysis using the Cox regression method. Prohibitin 1 activation seems to be an early event, whereas c-Met overexpression may be important for the progression of cervical adenocarcinomas. Evaluation of c-Met expression status may identify a subset of patients with cervical adenocarcinoma who require more intensive treatment.

The effect of methylenetetrahydrofolate reductase polymorphism C677T on cervical cancer in Korean women

OBJECTIVES

Methylenetetrahydrofolate reductase (MTHFR) gene is associated with DNA hypomethylation, an established hallmark of human cancer cells. The aim of this study was to examine the effect of MTHFR polymorphism C677T on cervical carcinogenesis in the context of other environmental factors, such as smoking, parity, and age at the first intercourse.

METHODS

The study subjects were patients who were pathologically diagnosed with cervical neoplasia and who had a positive result for human papillomavirus (N = 462), and they were compared to normal healthy women as normal controls (N = 454). Genotypes of the patients and control samples were assayed by single base primer extension assay using SNapShot assay kit.

RESULTS

Compared with MTHFR C/C, the odds ratio (95% confidence interval) for MTHFR T/T was 1.4 (0.9-2.3) for invasive cervical cancer and 1.3 (0.8-2.3) for cervical intraepithelial neoplasia (CIN) II or III. The risks for invasive cervical cancer were higher with less than 40 years old at diagnosis (2.1, 1.0-4.3), than with over 40 years old at diagnosis (1.2, 0.7-2.2). Current smoking women with early onset with MTHFR T/T had a 4.7 (0.6-36.2) times higher risk of cervical cancer. The risks of MTHFR T/T or C/T also increased for women with an early age of first intercourse or for women with two or more children, as compared with MTHFR C/C.

CONCLUSION

Polymorphisms of MTHFR are associated with a higher risk of developing cervical cancer, and in particular for an early onset of cervical carcinogenesis.

The site of infection and ethnicity of the patient influence the biological pathways to HPV-induced mucosal cancer

High-risk human papillomaviruses are the causative agents of cervical cancer and are also believed to be aetiologically involved in a subset of squamous cell carcinomas of the head and neck region, especially the tonsil. Cervical cancers arise through disruption of the pathways of p53 and the product of the retinoblastoma gene by the human papillomavirus oncoproteins E6 and E7. It is generally assumed that the same pathways are involved in human papillomavirus-induced carcinogenesis at other mucosal surfaces. However, the patterns of expression of cell cycle proteins targeted by human papillomavirus E6 and E7 in cancers from different anatomic sites have been inconsistent, due to either biologic or technological factors. In this study, 73 human papillomavirus, 16-positive cervical squamous cell carcinomas (35 from Australian and 38 from Chinese women) were analysed for the expression of p53, pRb, p16(INK4A), p21(CIP1/WAF1), p27(KIP1) and cyclin D1 by semiquantitative immunohistochemistry. Cervical cancers from Chinese women were found to be significantly more likely to overexpress p53, pRb, p21 and p27 than their Australian counterparts. These findings were compared with those from 31 human papillomavirus 16-positive tonsillar squamous cell carcinomas, all of Australian origin, tested using the same methodology. Comparisons of the tonsillar and combined cervical data showed that tonsillar cancers were significantly more likely to be p53-positive, whereas cervical cancers were significantly more likely to overexpress pRb, p16 and p27. When the tonsillar data were compared with cervical data from Australian women, the associations for p53 and pRb remained. These findings represent new evidence that the molecular pathways to human papillomavirus-induced mucosal cancer may be influenced by anatomic location and ethnicity.

Polymorphism p53 codon-72 and invasive cervical cancer: a meta-analysis

OBJECTIVES

Although some studies have reported that the arginine isoform on codon 72 of p53 increases the susceptibility to invasive cervical cancer, such data remain controversial. The objective of this study was to quantitatively summarize the evidence for such a relationship.

METHODS

Our data sources consisted of a MEDLINE search of the literature published before December 2002, bibliography review, and expert consultation. Thirty-seven studies met the inclusion criteria. Information on sample size, study design, Hardy-Weinberg equilibrium, and method of genotype determination was abstracted by two reviewers using a standardized protocol. The overall odds ratio (OR) of the p53 gene on invasive cervical cancer was estimated using the Mantel-Haenzel method.

RESULTS

The overall OR (95% confidence interval) for cervical cancer among those with the homozygous mutant (Arg/Arg) was 1.2 (1.1-1.3, P=0.001) compared with those with the heterozygous mutant (Arg/Pro). By a cellular type of cervical cancer, the overall OR among those with Arg/Arg was statistically significant in adenocarcinomas (1.7, 1.1-2.6, P=0.024), but not in squamous cell carcinomas (1.1, 0.9-1.2, P=0.960), compared with Pro/Pro. Compared with Arg/Pro, the OR among those with Arg/Arg was statistically significant in HPV types 16 (1,5, 1.2-2.0, P=0.002).

CONCLUSIONS

Overall, the p53 gene was associated with increased risk for invasive cervical cancer. However, the risk varied by country, cellular, and HPV type.

The prognostic impact of cyclin dependent kinase inhibitors p21WAF1, p27Kip1, and p16INK4/MTS1 in adenocarcinomas of the uterine cervix: an immunohistochemical evaluation of expression patterns in population-based material from 142 patients with international federation of gynecology and obstetrics stage I and II adenocarcinoma

BACKGROUND

The authors assessed the prognostic significance of abnormal cyclin dependent kinase inhibitor (CDKI) expression in adenocarcinomas of the uterine cervix.

METHODS

Population-based, archival material from patients with International Federation of Gynecology and Obstetrics (FIGO) Stage I and II cervical adenocarcionmas from 2 5-year periods (1976-1980, n = 82 patients; 1986-1990, n = 142 patients) was examined for expression of p21(WAF1), p27(Kip1), and p16(INK4/MTS1) using immunohistochemical techniques.

RESULTS

Rates of tumors with low levels of nuclear expression of p27 and p16 were lower during the period 1976-1980 (P < 0.01), suggesting bias due to unbuffered formalin. Analyses that were restricted to patients from 1986-1990 showed positive associations between all three CDKIs (P < 0.05). Low p16 expression was associated with higher FIGO stage (P = 0.01), age older than 55 years (P = 0.01), and deep invasion (P = 0.003). No significant associations with stage, age, or histopathologic parameters were found for p21 or p27. Significant associations with tumor differentiation were not seen for any CDKI. Kaplan-Meier plots showed diverging survival curves for p21 and p27 expression, but the differences were not significant. In multivariate analysis, low p27 expression and high p16 expression were strong predictors of a poor prognosis (p27: < 40% nuclear staining; P = 0.001; hazard ratio, 3.18; p16: < 40% nuclear staining; P < 0.001; hazard ratio, 0.16). Low p27 expression was of prognostic significance only if it was analyzed together with p16 expression. Further evaluation indicated that patients with different phenotypic p27/p16 combinations may have different outcomes.

CONCLUSIONS

Aberrant expression patterns of CDKIs were predictors of prognosis for patients with FIGO Stage I or II cervical adenocarcinoma. Analysis of CDKI expression in this patient group may prove clinically useful.

The effect of codon 98 of the FHIT gene on cervical cancer in Korean women

The Fragile Histadine Triad (FHIT) is a putative tumor suppressor gene involved in different tumors. The objective of this study was to examine the effect of codon 98 of FHIT on cervical carcinogenesis. The study subjects were patients who were pathologically diagnosed with cervical neoplasia and who had a positive result for human papillomavirus (n = 567) compared to normal healthy women as normal controls (n = 506). The FHIT-specific sequences of DNA from peripheral blood samples from study subjects were determined by PCR using allele-specific primers and were compared with those of the controls. The genetic susceptibility of codon 98 of the FHIT gene (3p14.2) in cervical carcinogenesis was determined by examining the effect of the gene and environmental factors vs. the different stages of cervical intraepithelial lesions and the different histopathologic types of invasive cervical cancers. On assessing FHIT polymorphisms, the percentages of individuals homozygous for the T allele, homozygous for the C allele, and heterozygous for these two alleles were 42.1%, 11.3, and 46.6% in the control group. The corresponding figures were 39.5%, 14.8%, and 45.7% among in women with cervical cancer. Compared with FHIT T/ T, odds ratio (95% confidence interval) for FHIT C/C was 1.4 (0.8-2.5) for invasive cervical cancer and 1.7 (0.9-3.1) for cervical intraepithelial neoplasia (CIN) II or III. The risks for invasive cervical cancer were higher with early onset cervical carcinogenesis (2.3, 1.0-5.5, P = 0.0438), than with late onset (1.0, 0.5-2.1, P = 0.9306). The risks of FHIT C/C or C/ T also increased for ever smokers or women with two or more children compared with FHIT T/ T. Polymorphisms of FHIT are associated with a higher risk of developing cervical cancer, in particular early onset cervical carcinogenesis.

The value of HPV DNA typing in the distinction between adenocarcinoma of endocervical and endometrial origin

AIMS

Distinguishing between adenocarcinomas of endocervical and endometrial origin histologically can be difficult, particularly in small biopsies. Most endocervical adenocarcinomas contain human papillomavirus (HPV) deoxyribonucleic acid (DNA) of 'high-risk' (HR) types, whereas this has not been consistently demonstrated in endometrial adenocarcinomas. The aim of this study was to determine whether HPV DNA testing could aid in this differential diagnosis.

METHODS

The frequency of HPV DNA in paraffin-embedded tissue samples from 50 endocervical and 50 endometrial adenocarcinomas was investigated using polymerase chain reaction (PCR) amplification techniques involving (i) a screening HPV test followed by HPV DNA sequencing, and (ii) a test designed to detect HR genotypes 16, 18, 31, 33, 35, 45 and 58. Control specimens included cervical intraepithelial neoplasia (CIN) III lesions, squamous cell carcinomas (SCCs) of the cervix and lung, and colonic adenocarcinomas. Measures to minimise cross-contamination were implemented.

RESULTS

The screening test followed by HPV DNA sequencing had the highest sensitivity. By this test HR HPV DNA was detected in 11 of 11 (100%) cervical intraepithelial neoplasia (CIN III) lesions, nine of 10 (90%) cervical SCCs, none of 10 (0%) colorectal adenocarcinomas and none of 10 (0%) SCCs of the lung. Thirty-nine (78%) endocervical adenocarcinomas contained HR HPV DNA, compared to one (2.0%) endometrial adenocarcinoma.

CONCLUSIONS

The results suggest that HPV DNA testing could be a useful adjunct in distinguishing between endocervical and endometrial adenocarcinomas in curettings or small biopsy specimens.

Immunohistochemistry in gynecological pathology

Although the majority of diagnoses in gynecological pathology are established on examination of routine hematoxylin and eosin stained sections, additional tests are occasionally required. Immunohistochemistry is widely used to provide additional diagnostic information in problematic cases. This review touches on some of the basics of the procedure, presents an example immunohistochemical panel, and discusses some of the most common immunohistochemical markers used in diagnostic gynecological pathology. Differential diagnostic problems and relevant immunohistochemical stains for the vulva, vagina, cervix, uterus, and ovary are also addressed.

Role of cell-cycle regulatory proteins in gynecological cancer

Human malignant tumors are characterized by abnormal proliferation resulting from alterations in cell-cycle regulatory mechanisms. This review summarizes the current knowledge about these aberrations in malignant tumors of the ovary, endometrium, cervix uteri, and vulva. The data indicate that analysis of single cell cycle stimulating or inhibiting proteins partly produces unexpected, apparently paradoxical results, and cell-cycle regulatory pathways should be regarded as a whole in order to identify the molecular mechanisms leading to abnormal tumor cell proliferation. For the papillomavirus (HPV)- associated cervical and vulvar carcinomas, the manifold effects of the viral oncogenes E6 and E7 on cell-cycle control are described.

Potential biomarkers for head and neck squamous cell carcinoma

OBJECTIVE

The purpose of the study was twofold: 1) to search for potential biomarkers that were overexpressed in cell lines that could represent both a clinical premalignant (immortalized) and a malignant state, and 2) to attempt to correlate metallothionein gene expression with clinical outcome in laryngeal carcinoma.

STUDY DESIGN

A series of in vitro experiments were used to unearth differentially expressed genes among normal, immortalized and tumorigenic cell lines. Secondarily, a retrospective analysis was undertaken.

METHODS

Differential display analysis was conducted to identify differentially expressed genes between human papillomavirus-infected immortalized HOK16B and benzo[ ]pyrene-derived tumorigenic cell line, HOK16B-BaP-T. The cell-specific expressions were examined by Northern blot analysis and compared with other known immortalized and cancer cell lines. Immunohistochemical staining was also conducted to localize metallothionein (MT I/II) protein expression among the different cell lines studied. A retrospective analysis of laryngeal specimens from archival tissues of 29 cancer patients who underwent primary surgical resection was also undertaken after immunohistochemical staining.

RESULTS

Twenty-one differentially expressed complementary cDNA clones, both novel and known, were identified using the differential display analysis. Northern blot analysis confirmed that clone 6 hybridized to a 1.6-kb RNA in HOK16B-Bap-T cell line. Clone 4 showed decreased expression in immortalized and cancer cell compared with NHOK. MT I/II transcript was observed in HOK16B, which was further elevated in HOK16B-Bap-T. Retrospective analysis showed that high immunoreactivity to MT I/II in surgically resected laryngeal cancer specimen correlated with increased frequency of recurrence within 2 years of surgery.

CONCLUSION

These findings suggest that clone 4 may potentially function as a tumor suppressor gene, which may be significant in tumor progression and invasion. Clone 6 may participate in viral-mediated oncogenic transformation of normal cells. Clone 6 may also have potential as a tumor maker differentiating normal from malignant tissue, as in the determination of surgical resection margins. MT I/II gene product may serve as a prognostic biomarker for laryngeal squamous cell carcinoma. The differentially expressed genes and gene products may serve as sensitive biomarkers for improved early detection, diagnosis, and prognosis of head and neck squamous cell carcinoma.

p16INK4a is a useful marker for the diagnosis of adenocarcinoma of the cervix uteri and its precursors: an immunohistochemical study with immunocytochemical correlations

p16 is a tumor suppressor gene that plays a central role in the regulation of the cell cycle. In squamous cervical cancers, overexpression of p16 is induced by HPV and associated with the carcinogenesis of cervical epithelia. The aim of this study was to determine whether immunostaining of p16 is useful in detecting adenocarcinomas of the cervix uteri in histologic and cytologic routine specimens. A total of 45 surgical specimens, including 18 cases of invasive carcinoma, 8 cases of adenocarcinoma in situ, 4 cases of endocervical glandular atypia (cervical glandular intraepithelial neoplasia), and 15 reactive lesions of the endocervical glands were immunostained using a specific anti-human p16 monoclonal antibody (clone E6H4, mtm laboratories AG, Heidelberg, Germany). Furthermore, immunocytochemical analysis was performed on 10 preoperative ThinPrep cytologic samples with abnormal glandular cells and compared with the human papillomavirus status as assessed with the Hybrid Capture II test. p16 was detected immunohistochemically in all 26 cases of adenocarcinoma of the cervix uteri, including 18 invasive and 8 in situ carcinomas. Only a focal expression was evidenced in the four specimens with endocervical glandular atypia, and no reaction was found in reactive lesions. Also, the immunocytochemical analysis on the 10 ThinPrep specimens evidenced a strong expression of p16 in neoplastic endocervical cells. In all cases this was associated with a high-risk HPV-positive typing. p16 is a useful marker for the detection of the adenocarcinoma of the cervix uteri and its precursors. The immunocytochemical detection on ThinPrep specimens may contribute to an early detection of endocervical lesions.

Immunohistochemical localization of cdc6 in squamous and glandular neoplasia of the uterine cervix

CONTEXT

Cdc6 has been extensively studied as a marker for cellular proliferation that is expressed during the normal cell cycle. Recent studies indicate that Cdc6 may be a marker for cervical intraepithelial neoplasia (CIN) and carcinoma; however, the histologic distribution of Cdc6 has not been explicitly defined. Expression of Cdc6 in the endocervical mucosa also remains unexplored.

OBJECTIVE

The goal of the current study was to evaluate the distribution of Cdc6 protein, MIB-1 protein, and human papillomavirus (HPV) DNA in a broad range of cervical tissues, including normal, potentially premalignant, and malignant lesions of the ectocervical and endocervical mucosa.

METHODS

We used an indirect immunoperoxidase method to stain formalin-fixed, paraffin-embedded tissues and frozen tissues, including biopsy and hysterectomy specimens, for Cdc6 and MIB-1 proteins, and we used in situ hybridization to detect HPV DNA in a subset of cases.

RESULTS

Cdc6 staining was exclusively nuclear and was present in both squamous and glandular epithelial cells of histologic sections. Cdc6 staining was rarely present in specimens of normal cervical squamous mucosa (2/84, 2.4%) or in specimens with squamous metaplasia (3/59, 5.1%) and was not detected in normal endocervical glands (0/84). Staining was present in most cases of CIN I (31/48, 65%). Staining was present in the majority of cases of CIN II (25/28, 89%) and in all cases of CIN III (36/36) and squamous cell carcinomas (34/34). The proportion of cells staining for Cdc6 increased with the grade of dysplasia, and the proportion of stained cells in squamous cell carcinomas was similar to that in lesions of high-grade dysplasia. Cdc6 staining was present in the majority of cases in glandular lesions including adenocarcinoma in situ (11/14, 79%) and adenocarcinoma (8/10, 80%). The histologic distribution of Cdc6-immunoreactive cells was similar to that of cells with a strong signal for HPV DNA, but Cdc6 protein and HPV DNA did not colocalize at the level of individual cells.

CONCLUSION

Cdc6 expression is a marker for high-grade cervical squamous and glandular dysplasia and carcinoma and is associated with HPV infection. The mechanistic basis of the association between HPV infection and Cdc6 immunopositivity remains to be determined but may represent either up-regulation of Cdc6 expression or stabilization of the Cdc6 protein.

Changes in retinoblastoma gene expression during cervical cancer progression

The role of tumour suppressor genes in the development of human cancers has been studied extensively. In viral carcinogenesis, the inactivation of suppressor proteins such as retinoblastoma (pRb) and p53, and cellular oncogenes overexpression, such as c-myc, has been the subject of a number of investigations. In uterine-cervix carcinomas, where high-risk human papillomavirus (HPV) plays an important role, pRb and p53 are inactivated by E7 and E6 viral oncoproteins, respectively. However, little is known about the in situ expression of some of these proteins in pre-malignant and malignant cervical tissues. On the other hand, it has also been demonstrated that c-myc is involved in cervical carcinogenesis, and that pRb participates in the control of c-myc gene expression. By using immunostaining techniques, we investigated pRb immunodetection pattern in normal tissues, squamous intraepithelial lesions (SILs) and invasive carcinomas from the uterine cervix. Our data show low pRb detection in both normal cervical tissue and invasive lesions, but a higher expression in SILs. C-Myc protein was observed in most of the cellular nuclei of the invasive lesions, while in SILs was low. These findings indicate a heterogeneous pRb immunostaining during the different stages of cervical carcinogenesis, and suggest that this staining pattern could be a common feature implicated in the pathogenesis of uterine-cervix carcinoma.

Symposium part IV: investigative approaches to endocervical pathology

There is continuing interest in the study of adenocarcinoma of the cervix and its precursors because of its increase in incidence, both absolute and relative, to squamous neoplasia and the complexity of benign glandular lesions with which endocervical neoplasia may be confused. Investigative techniques may be applied as aids to diagnosis, as prognostic markers, and to further our understanding of etiopathogenesis. This article focuses on recent developments in the four areas of epithelial glycoproteins, molecular markers, cell proliferation markers, and human papillomaviruses as applied to endocervical pathology. Although immunohistochemistry remains dominant, a wide range of other techniques is discussed.

The relevance of oncogenes as prognostic markers in cervical cancer

To study the prevalence of the oncogenes c-myc, IFN-alpha; c-erbB2; H-ras codon 12, 13, and 61; c-fos; and E6/E7 oncogenes of human papillomavirus (HPV) 16 in patients with invasive carcinoma of the cervix and their prognostic significance, genomic DNA and RNA were isolated from tissues of 275 patients in Singapore with nonmetastatic cervical cancer and 32 patients with normal cervix. The levels of expression of the various oncogenes were quantified by PCR using the respective primers. When the PCR data on the DNA were analyzed by the log-rank test, IFN gamma (P = 0.02) and H-ras codon 12 and 13 (P = 0.02) were found to be prognostic. In the multivariate analysis, a statistically significant trend for increasing risk with higher quartiles was found for c-myc (P = 0.007) and c-erbB2 (P = 0.03). After adjusting for age and stage, a correlation appears between the amplification of the oncogenes c-myc, c-erbB2, and H-ras codon 12, 13, and 61 and the development of recurrent cervical cancer. Further adjustment to include the parameters of treatment and histology type did not change the outcome of the correlation observed.

P53 immunohistochemical expression: messages in cervical carcinogenesis

AIMS

The pattern of p53 expression was studied in pre-invasive and invasive cervical carcinoma in an attempt to clarify its role in cervical carcinogenesis.

METHODS

A total of 234 invasive cervical carcinomas (152 squamous cell carcinomas, 61 adenocarcinomas and 21 adenosquamous carcinomas) and 16 cervical intraepithelial neoplasia (CIN) I, six CIN II and 25 CIN III were immunohistochemically studied for p53.

RESULTS

p53 was detected more frequently in CIN and invasive carcinoma (100% of CIN I, 74.2% CIN II + III and 70.1% invasive carcinoma) compared with benign cervices (P< 0.001); however, only three squamous cell carcinomas, 11 adenocarcinomas and two adenosquamous carcinomas exhibited p53 expression in >75% of tumour nuclei. Six of the 11 adenocarcinomas and both adenosquamous carcinomas were poorly differentiated compared with one of the three squamous carcinomas. p53 immunoreactive cells were randomly distributed in invasive carcinoma, confined to the lower third of the epithelium in CIN I, reached the middle third in 20% of CIN II and upper third in 16.6% of CIN III.

CONCLUSIONS

Assuming that p53 immunoreactivity indicates gene mutation when the majority (> 75%) of neoplastic cells express p53, p53 mutations would seem uncommon in cervical carcinogenesis. Nonetheless, glandular malignancies, in particular poorly differentiated variants, may show a higher frequency of mutation. p53 was detected more frequently in CIN I compared with CIN II/III and invasive carcinoma which may be due to p53 protein degradation following interaction with high risk human papillomavirus E6 protein in CIN II/III and invasive carcinoma.

Expression of vascular endothelial growth factor in adenocarcinomas of the uterine cervix and its relation to angiogenesis and p53 and c-erbB-2 protein expression

OBJECTIVE

The purpose of this study was to evaluate vascular endothelial growth factor (VEGF) expression in adenocarcinomas of the uterine cervix and its correlation with clinicopathologic features, angiogenesis, and expression of p53 and c-erbB-2 proteins.

METHODS

Thirty-seven cases of FIGO clinical stage I and II adenocarcinoma of the uterine cervix were examined by immunohistochemical studies with anti-VEGF, anti-CD34, anti-p53, and anti-c-erbB-2 antibodies. Computerized image analysis was used to evaluate microvessel density (MVD).

RESULTS

Thirty-one tumors (83.8%) were classified as VEGF positive. Six tumors (16.2%) showed p53 protein expression while 11 tumors (29.7%) expressed the c-erbB-2 protein. MVD ranged from 13.3 to 44.8, with a median value of 25.5 (26.9 +/- 7.5). Tumors expressing VEGF had a significantly higher MVD than those that did not express VEGF (P < 0.05). VEGF expression was significantly associated with c-erbB-2 protein expression (P < 0.05). The spatial distributions of both VEGF expression and c-erbB-2 expression were similar in tumor tissues. In univariate log-rank analysis, stage (P = 0.0250), lymphovascular space invasion (P = 0.0156), and MVD (P = 0.0360) were associated with shortened survival.

CONCLUSION

VEGF expression plays a role in promoting angiogenesis in cervical adenocarcinomas and c-erbB-2 is likely to be involved in the up-regulation of VEGF expression.

Human papillomavirus infection among Egyptian females with cervical carcinoma: relationship to spontaneous apoptosis and TNF-alpha

OBJECTIVES

This study was designed to detect HPV type-16 in Cervical carcinoma (CC) tissue specimens. The results were correlated with clinicopathological parameters of the carcinoma, with spontaneous apoptosis and with immunoreactivity to TNF-alpha antibodies.

METHODS

Fresh frozen tissue specimens representing 30 cases of cervical carcinoma as well as 20 normal cervical tissues (NCT) were the subjects of this study. HPV-16 DNA was detected by Polymerase Chain Reaction (PCR). The occurrence of spontaneous apoptotic cell death was analyzed by the apoptosis assay. Apoptotic cells were also counted by light microscopy and the apoptotic index (AI) was calculated. Electron microscopy was used to confirm the morphology of apoptotic cells. TNF-alpha was quantified using EIA kit.

RESULTS

HPV-16 DNA was more frequent in CC than in NCT. No correlation was observed between HPV infection and grade, stage or pathologic type of CC. The occurrence of spontaneous apoptosis was significantly higher in CC than in NCT, where it was correlated to advanced tumor stage and tumor pathology being more in adenocarcinoma (AC) than in squamous cell carcinoma (SCC). Moreover, AI was negatively correlated to HPV-16 infection. TNF-alpha levels were significantly higher in CC vs. NCT, where they were positively correlated to advanced tumor stage. TNF-alpha levels were correlated to DNA fragmentation and AI (r = 0.47 and 0.57 respectively). A cut-off value for TNF-alpha was calculated to be 9.1 pg/mg protein (using ROC curve). At the determined cut-off point the sensitivity was 70% and the specificity was 80%.

CONCLUSIONS

HPV infection, high levels of TNF-alpha and spontaneous apoptosis were strongly associated with malignant phenotype of cervical tissues. Rate of spontaneous apoptosis was higher in AC compared to SCC. On the other hand, HPV negativity was correlated with AI. Moreover, TNF-alpha and apoptotic cell death were correlated to each other as well as to tumor progression. No correlation was detected between TNF-alpha and HPV-16 infection.

Immunohistochemical expression of gastric mucin and p53 in minimal deviation adenocarcinoma of the uterine cervix

Comparative immunostaining with antibodies against gastric mucin and p53 was performed on 6 cases of minimal deviation adenocarcinoma (MDA) of the uterine cervix. The MDAs consisted of predominant areas of glands lined by extremely well-differentiated tall columnar epithelial cells with little cytological atypia and minor foci of less well-differentiated glandular epithelium with a minor degree of nuclear atypia. Immunostaining for gastric mucin with a monoclonal antibody HIK1083 revealed that all the tumors areas of typical MDA were partly immunoreactive for HIK1083, but the coexisting less well-differentiated glands were essentially negative. Four MDAs focally contained cells with p53 positive nuclei that were located exclusively in the less well-differentiated cells that lacked gastric mucin. In the pelvic lymph nodes in 2 cases, most of the metastatic tumor was less differentiated and a positive reaction for HIK1083 was observed only in small foci of typical MDA. No significant overexpression of p53 was observed in the metastases. Immunohistochemical expression of gastric mucin and p53 may be related to the histological differentiation of MDA, and detection of p53 overexpression may help to identify critical steps in the local progression of MDA.

CDKN2A/p16 inactivation is related to pituitary adenoma type and size

p16 (CDKN2A, MTS1, INK4A) status at genomic and protein levels was analysed and correlated with clinico-pathological features in 72 pituitary adenomas. Methylation of CpG islands of promoter/exon 1 sequences was found in most gonadotroph, lactotroph, plurihormonal, and null cell adenomas (36 of 44, 82%), but it was rare in somatotroph (1 of 13 cases, 8%) and corticotroph adenomas (1 of 15 cases, 7%). Homozygous CDKN2A deletion was restricted to rare somatotroph (15%) and corticotroph adenomas (13%). Immunohistochemical p16 protein expression was observed in the normal adenohypophysis, whereas it was absent in 60 of 72 (83%) tumours and reduced in another ten (14%) tumours. Staining for p16 was only seen in 5 of 15 (33%) corticotroph, 3 of 13 (23%) somatotroph, 3 of 5 (60%) plurihormonal, and 1 of 19 (5%) null cell adenomas. p16 immunonegativity without CDKN2A methylation or deletion occurred in 22 tumours, including most somatotroph and corticotroph adenomas (15 of 28, 54%). Both CDKN2A alterations and p16 negativity were related to larger tumour size. Patients with p16-negative tumours were older than patients with p16-positive tumours. These data suggest that p16 down-regulation is common in all adenoma types. The mechanisms of p16 down-regulation probably involve CDKN2A methylation in most types, but remain to be determined in somatotroph and corticotroph adenomas. These findings also suggest that p16 down-regulation is usually not an initial event, but is acquired during adenoma progression.

Prevalence of human papillomavirus DNA in different histological subtypes of cervical adenocarcinoma

The prevalence of human papilloma virus (HPV) DNA in different histological subtypes of cervical adenocarcinoma and related tumors was examined using formalin-fixed, paraffin-embedded tissue samples from 105 primary cervical adenocarcinomas and adenosquamous carcinomas. Broad-spectrum HPV DNA amplification and genotyping was performed with the SPF10 primer set and line probe assay (LiPA), respectively. HPV DNA was detected in 82 of 90 (91%) mucinous adenocarcinomas, encompassing endocervical, intestinal, and endometrioid histological subtypes, and in nine of nine adenosquamous tumors (100%). HPV DNA was not detected in any nonmucinous adenocarcinomas including clear cell, serous, and mesonephric carcinomas (0/6). The most common viral types detected in adenocarcinoma were HPV 16 (50%) and HPV 18 (40%), followed by HPV 45 (10%), HPV52 (2%), and HPV 35 (1%). Multiple HPV types were detected in 9.7% of the cases. In conclusion, mucinous adenocarcinomas and adenosquamous carcinomas of the cervix demonstrate a very high prevalence of HPV DNA, similar to that reported for cervical squamous cell carcinoma. Only rare histological variants of cervical adenocarcinoma seem unrelated to HPV infection.

Association between activated K-ras and c-erbB-2 oncogenes with "high-risk" and "low-risk" human papilloma virus types in preinvasive cervical lesions

Clinical and epidemiological data have linked cervical cancer to the Human Papilloma Virus (HPV) infection. However, the presence of HPV infection alone is not enough to cause tumorigenesis, suggesting a role for additional host-cell genetic factors. The aim of the present work was to study the association of K-ras and c-erbB-2 mutations in cervical tissue samples with different grades of dysplasia and infected with HPV-6 ("low-risk" type) or HPV-16 and HPV-18 ("high-risk" types). Negative HPV-DNA samples were used as controls. The detection of K-ras and c-erbB-2 activation were performed by Artificial Refractory Mutation System (ARMS)-PCR and semiquantitative PCR, respectively. Statistical analysis showed a highly significant difference in K-ras codon 12 mutation frequency between high-risk and low-risk HPV-infected samples (p<0.05). On the other hand, amplification of the c-erbB-2 oncogene appeared associated to tissue samples infected with HPV-6 (p<0.003). Cervical carcinoma appears to arise from a series of well-characterized progressive histological changes, but the genetic alterations necessary for cervical tumorigenesis are not yet clear. These results raise the possibility for a role of certain proto-oncogenes and their activation in cervical neoplasia.

Tumor necrosis factor-alpha promotes human papillomavirus (HPV) E6/E7 RNA expression and cyclin-dependent kinase activity in HPV-immortalized keratinocytes by a ras-dependent pathway

Tumor necrosis factor-alpha (TNF-alpha) inhibits growth of normal cervical keratinocytes but stimulates proliferation of human papillomavirus (HPV)-immortalized and cervical carcinoma-derived cell lines when mitogens such as epidermal growth factor (EGF) or serum are depleted. Current work identifies the mechanism of growth stimulation. TNF-alpha promoted cell cycle progression by increasing expression of HPV-16 E6/E7 RNAs and enhancing activity of cyclin-dependent kinase (cdk)2 and cdc2 after 3 d. Increased kinase activity was mediated by upregulation of cyclins A and B and decreases in cdk inhibitors p21(waf) and p27(kip). TNF-alpha stimulated these changes in part by increasing transcription and stabilization of RNA for amphiregulin, an EGF receptor ligand, and amphiregulin directly increased HPV-16 E6/E7 and cyclin A RNAs. To define which components of the EGF receptor signaling pathway were important, HPV-immortalized cells were transfected with activated or dominant negative mutants of Ha-ras, raf, or MAPKK. Expression of activated Ha-ras maintained HPV-16 and cyclin gene expression and promoted rapid growth in the absence of EGF. Furthermore, ras activation was necessary for TNF-alpha mitogenesis as transfection with a dominant negative ras mutant (Asn-17) strongly inhibited growth. Thus, activation of ras promotes expression of HPV-16 E6/E7 RNAs, induces cyclins A and B, and mediates growth stimulation of immortal keratinocytes by TNF-alpha. These studies define a pathway by which ras mutations, which occur in a subset of cervical cancers, may contribute to pathogenesis. Mol. Carcinog. 27:97-109, 2000. Published by Wiley-Liss, Inc.

Alteration of p16 and p15 genes in human uterine tumours

The roles of the p16 and p15 inhibitor of cyclin-dependent kinase tumour suppressor genes were examined in human uterine cervical and endometrial cancers. p16 mRNA, examined by reverse transcription polymerase chain reaction (RT-PCR), was significantly reduced in five of 19 (26%) cervical and four of 25 (16%) endometrial tumours. Reduced expression of p16 protein, detected by immunohistochemistry, occurred even more frequently, in nine of 33 (27%) cervical and seven of 37 (19%) endometrial tumours. Hypermethylation of a site within the 5'-CpG island of the p16 gene was detected in only one of 32 (3%) cervical tumours and none of 26 endometrial tumours. Homozygous p16 gene deletion, evaluated by differential PCR analysis, was found in four of 40 (10%) cervical tumours and one of 38 (3%) endometrial tumours. Homozygous deletion of p15 was found in three of 40 (8%) cervical tumours and one of 38 (3%) endometrial tumours. PCR-SSCP (single-strand conformation polymorphism) analysis detected point mutations in the p16 gene in six (8%) of 78 uterine tumours (four of 40 (10%) cervical tumours and two of 38 (5%) endometrial tumours). Three were mis-sense mutations, one in codon 74 (CTG-->ATG) and one in codon 129 (ACC-->ATC), both in cervical carcinomas, and the other was in codon 127 (GGG-->GAG) in an endometrial carcinoma. There was one non-sense mutation, in codon 50 (CGA-->TGA), in an endometrial carcinoma. The remaining two were silent somatic cell mutations, both in cervical carcinomas, resulting in no amino acid change. These observations suggest that inactivation of the p16 gene, either by homologous deletion, mutation or loss of expression, occurs in a subset of uterine tumours.

Detection of human papillomavirus types in cervical adenocarcinoma by the polymerase chain reaction

OBJECTIVE

To determine the human papillomavirus (HPV) types in cervical adenocarcinoma of patients from Taiwan.

METHODS

DNA was extracted from fixed tissues and polymerase chain reaction was performed in conjunction with a unique probe, pRSA I, allowing simultaneous detection of HPV types 6, 11, 16, 18, 31 and 33 from amplified HPV DNAs after endonuclease, RsaI, digestion.

RESULTS

Of 69 tissues examined, 31.9% (22/69) were found to contain HPV DNA. Among 22 HPV-positive specimens, no HPV types 6, 11, 31 and 33 were detected. On the other hand, HPV 16 and HPV 18 were found in 11 (15.9%) and 10 (14.5%) of HPV-positive specimens, respectively. One specimen (1.5%) was found to contain both HPV 16 and 18 DNAs.

CONCLUSIONS

Our findings support that HPV 18, along with HPV 16, may play a certain role in the adenocarcinoma pathogenesis of the uterine cervix.

Molecular events in uterine cervical cancer

OBJECTIVE

To review the literature regarding the molecular events which occur in the development of uterine cervical cancer, with particular reference to human papillomavirus (HPV) infection.

METHODOLOGY

Bibliographic searches of Medline and the ISI citation databases using appropriate keywords, including the following: papillomavirus, cervix, pathology, cyclin, chromosome, heterozygosity, telomerase, smoking, hormones, HLA, immune response, HIV, HSV, EBV.

CONCLUSIONS

It has become clear that most cervical neoplasia, whether intraepithelial or invasive, is attributable in part to HPV infection. However, HPV infection alone is not sufficient, and, in a small proportion of cases, may not be necessary for malignant transformation. There is increasing evidence that HPV gene products interfere with cell cycle control leading to secondary accumulation of small and large scale genetic abnormalities. This may explain the association of viral persistence with lesion progression but, in many patients, secondary factors, such as smoking and immune response, are clearly important. However, the mechanisms involved in the interaction between HPV and host factors are poorly understood.