Quantitative Assessment of HER-2/Neu Protein Concentration in Breast Cancer by Enzyme-Linked Immunosorbent Assay

Purpose

The HER-2/neu protein (p185) has become a promising target for antibody therapy in breast cancer. We tested the feasibility of a quantitative approach for HER-2/neu testing based on the analysis of tumor tissue extracts by an enzyme-linked immunosorbent assay (ELISA).

Experimental design

Tumor tissue extracts of primary human breast cancers (n=124) were prepared using a triton-based buffer. HER-2/neu concentration was quantified by ELISA. Paraffin-embedded tissue sections of the same tumors were analyzed by immunohistochemical staining applying the monoclonal HER-2/neu antibody TAB 250 (n=124) and by chromogenic in situ hybridization (CISH) (n=73).

Results

Concentrations of p185 in tissue extracts determined by ELISA varied from 1 to 927 ng per mg protein with a median of 25 ng/mg protein, whereas normal breast tissue showed values from 0.4 to 5.5 ng/mg with a median of 2.2 ng/mg (p<0.0001, Mann-Whitney U test). A significant correlation between p185 concentration and immunohistochemical staining was observed (p<0.0001, Kruskal-Wallis test). In addition, p185 concentration measured by ELISA was correlated with the degree of HER-2/neu gene amplification determined by CISH. HER-2/neu-amplified tumors had significantly higher p185 concentrations (median value 181 ng/mg protein) than non-amplified tumors (median value 20 ng/mg; p<0.0001, Mann-Whitney U test).

Conclusions

ELISA-based measurement of HER-2/neu protein concentration in breast cancer tissue extracts is feasible and provides quantitative results for p185 protein concentrations that correlate closely with HER-2/neu immunoscore and gene amplification.

[Categorization of uterine cervix tumors : What's new in the 2014 WHO classification]

In the 2014 WHO classification, squamous cell precursor lesions are classified as low-grade and high-grade intraepithelial lesions. LSIL corresponds to CIN1, HSIL includes CIN2 and CIN3. Only adenocarcinoma in situ (AIS) is accepted as precursor of adenocarcinoma and includes the stratified mucin-producing intraepithelial lesion (SMILE). Although relatively rare, adenocarcinoma and squamous cell carcinoma can be mixed with a poorly differentiated neuroendocrine carcinoma. Most cervical adenocarcinomas are low grade and of endocervical type. Mucinous carcinomas show marked intra- and extracellular mucin production. Almost all squamous cell carcinomas, the vast majority of adenocarcinomas, and many rare carcinoma types are HPV related. For low grade endocervical adenocarcinomas, the pattern-based classification according to Silva should be reported. Neuroendocrine tumors are rare and are classified into low-grade and high-grade, whereby the term carcinoid is still used.

[Diagnosis and differential diagnosis of cervical adenocarcinoma]

This overview summarizes pathogenetic and practical aspects of (sub-)classification of cervical glandular (pre-)neoplasias and, inter alia, calls into question the usefulness of grading. In the context of the differential diagnosis of benign "imitations", the phenotypic variability of glandular precancerous lesions and carcinomas is described as well as the use of special tests to distinguish them. With regard to carcinomas, the differential diagnosis of well-differentiated neoplasias is addressed including "minimal deviation" adenocarcinoma (MDA, malignant adenoma), carcinomas with endometrioid or villoglandular morphology, and mesonephric hyper- and neoplasias. Furthermore, knowledge of HPV-negative glandular (pre-)neoplasias is covered including "gastric-type" adenocarcinomas and diagnostic algorithms for discriminating between primary and secondary cervical adenocarcinomas. Finally, comments are offered on the difficulties in recognizing early invasive adenocarcinomas, especially also the pitfalls inherent in determining the depth of invasion.

The MYB-NFIB gene fusion-a novel genetic link between adenoid cystic carcinoma and dermal cylindroma

We have recently shown that the recurrent t(6;9)(q22 ∼ 23;p23 ∼ 24) translocation in adenoid cystic carcinoma (ACC) of the breast and head and neck results in a fusion of the two transcription factor genes MYB and NFIB. Here we demonstrate, for the first time, that benign sporadic, dermal cylindromas also express the MYB-NFIB gene fusion. RT-PCR and immunohistochemical analyses revealed that eight of 12 analysed tumours (67%) expressed MYB-NFIB fusion transcripts and/or stained positive for MYB protein. Nucleotide sequence analyses confirmed that the composition of the chimeric transcript variants identified was identical to that in ACC, suggesting a similar molecular mechanism of activation of MYB in cylindroma as in ACC. In contrast, no evidence for the presence of the MYB-NFIB fusion was found in other types of basaloid skin and salivary gland tumours, indicating that the fusion indeed has a restricted expression pattern. Our findings broaden the spectrum of neoplasms associated with MYB oncogene activation and reveal a novel genetic link between ACC and dermal cylindroma. These results, together with our previous observations, further strengthen the evidence for common molecular pathways of importance for the development of both benign and malignant breast, salivary and adnexal tumours.

Overexpression of TACE and TIMP3 mRNA in head and neck cancer: association with tumour development and progression

BACKGROUND

TACE/ADAM17 is a transmembranous protease that cleaves membrane-bound growth factors like EGFR ligands. TACE-dependent proteolysis is regulated by its inhibitor, tissue inhibitor of metalloproteinases 3 (TIMP3). This study analyses the role of TACE and TIMP3 mRNA expression in squamous cell carcinomas of the head and neck (HNSCCs).

METHODS

We analysed TACE and TIMP3 mRNA expression in HNSCCs from 106 patients by RNA in situ hybridisation.

RESULTS

TACE mRNA was upregulated in HNSCCs compared with dysplastic (P<0.05) and normal epithelia (P<0.001), with strong hybridisation signals in 21.9% of invasive tumour tissues and 4.5% of dysplasia. Elevated mRNA levels were accompanied by increased amounts of TACE protein in HNSCCs. TIMP3 mRNA expression in HNSCC-associated stroma was significantly higher than in the stroma adjacent to dysplastic or normal epithelia. Expression of TACE mRNA in HNSCCs was associated with tumour stage (P=0.019) and regional lymph node metastasis (P=0.009). Furthermore, levels of TACE mRNA in HNSCCs correlated with the expression of TIMP3 mRNA in HNSCC-associated stroma. Concomitantly, patients expressing high levels of TACE and TIMP3 mRNA showed significantly reduced overall survival compared with those with low mRNA levels.

CONCLUSION

Our results indicate an important role of TACE and TIMP3 during development and progression of HNSCCs.

One Step Nucleic Acid Amplification (OSNA) for intra-operative detection of lymph node metastases in breast cancer patients

21053

Background: Sentinel lymph node metastasis in breast cancer patients has conventionally been determined by intra- operative histopathological examination of frozen sections followed by definitive post-operative examination of permanent sections. The purpose of this study is to evaluate a more efficient method for intra-operative detection of lymph node metastasis in a clinical setting. Therefore, a new rapid method of detection of CK19 mRNA by One Step Nucleic Acid Amplification (OSNA) and Reverse Transcription Loop Mediated Isothermal Amplification (RT-LAMP) was tested against standard histological techniques. Methods: The clinical study was conducted at two facilities using 188 lymph nodes (46 patients). Lymph nodes from axillary dissected patients with breast cancer were divided into four slices. Alternate slices were used for the new method of CK19 mRNA detection (OSNA) and histopathological examination by hematoxylin & eosin and cytokeratin staining. For the analysis of concordance between both methods, the slices for histopathology were cut in 4 μm sections. For the OSNA method the other 2 slices were homogenised in a short sample preparation step. Afterwards CK19 mRNA was directly amplified from the tissue lysate within 16 minutes. Results: In the clinical study, an overall concordance rate between the OSNA assay and histopathology was 92%. Several discordant results are explainable with the expected uneven distribution of metastases within the lymph nodes. Conclusions: The study indicates that OSNA is a reliable and fast diagnostic tool for the detection of lymph node metastases in breast cancer patients. This method could be beneficial to avoid diagnostic delay for the patient or second surgery based on a post-operatively diagnosed positive lymph node.

No significant financial relationships to disclose.

[Significance of molecular-cytogenetic findings in mucoepidermoid carcinoma as an example of salivary gland tumors]

Chromosome translocations in tumors frequently give rise to fusion genes encoding proteins with oncogenic activities. Mucoepidermoid carcinomas (MEC) are characterized by a t(11;19)(q21-22;p13) translocation found in approximately 60% of the tumors. This t(11;19) translocation results in a fusion gene consisting of exon 1 of the MECT 1 gene and exons 2-5 of the MAML 2 gene. As a result of the t(11;19) a fusion protein is generated which, independent of NOTCH-ligands, activates the transcription of the NOTCH target gene HES 1. The altered function of MAML 2 causes a disruption of NOTCH signalling which suggests a novel mechanism of tumorigenesis. Pending the elucidation of the t(11;19) at the molecular level of an apparently identical chromosomal translocation in Warthin's tumor, the identification of the translocation in MEC by FISH- and/or RT-PCR-analyses may become important in diagnosis and might have prognostic relevance. Warthin's tumors are benign salivary gland neoplasms with a distinctive histomorphology and histogenesis completely different from MEC.

[Immunohistochemical characterization of salivary gland tumors with tissue micro-arrays]

Systematic analysis of gene expression in salivary gland tumors is necessary to identify genes associated with specific tumor types. From the salivary gland register of the University Hospital Hamburg-Eppendorf sufficient samples of various tumors were available to generate Tissue Micro-Arrays (TMA). In light of the considerable heterogeneity of salivary gland tumors, this study was aimed at evaluating the suitability of TMA in salivary gland diagnostics and research. Epithelial antigens are not sufficient for a tumor-type-specific characterization. Myoepithelial markers are suitable for distinguishing biphasic tumor types from purely epithelial tumors. The detection of amylase in acinic cell carcinomas, and the detection of steroid hormone receptors in these and other malignant salivary gland tumors particularly in combination with the expression of transcription factors, oncogenes and proliferation associated antigens result in characteristic expression profiles. These may prove to be valuable for further investigations, especially on the molecular level.

Expression and prognostic relevance of activated extracellular-regulated kinases (ERK1/2) in breast cancer

Extracellular-regulated kinases (ERK1, ERK2) play important roles in the malignant behaviour of breast cancer cells in vitro. In our present study, 148 clinical breast cancer samples (120 cases with follow-up data) were studied for the expression of ERK1, ERK2 and their phosphorylated forms p-ERK1 and p-ERK2 by immunoblotting, and p-ERK1/2 expression in corresponding paraffin sections was analysed by immunohistochemistry. The results were correlated with established clinical and histological prognostic parameters, follow-up data and expression of seven cell-cycle regulatory proteins as well as MMP1, MMP9, PAI-1 and AP-1 transcription factors, which had been analysed before. High p-ERK1 expression as determined by immunoblots correlated significantly with a low frequency of recurrences and infrequent fatal outcome (P=0.007 and 0.008) and was an independent indicator of long relapse-free and overall survival in multivariate analysis. By immunohistochemistry, strong p-ERK staining in tumour cells was associated with early stages (P=0.020), negative nodal status (P=0.003) and long recurrence-free survival (P=0.017). In contrast, expression of the unphosphorylated kinases ERK1 and ERK2 was not associated with clinical and histological prognostic parameters, except a positive correlation with oestrogen receptor status. Comparison with the expression of formerly analysed cell-cycle- and invasion-associated proteins corroborates our conclusion that activation of ERK1 and ERK2 is not associated with enhanced proliferation and invasion of mammary carcinomas.

Myoepitheliale Tumoren der Kopfspeicheldrüsen

This tutorial focuses on myoepithelial tumors of salivary glands, an entity with heterogeneous cytomorphology and inconsistent immunophenotype. Moreover, the clinical course cannot be predicted reliably from cytomorphological and immunophenotypic analysis. This heterogeneity causes problems in routine diagnostic, so that diagnosis ultimately rests on conventional histology. In a representative series of myoepitheliomas and malignant myoepitheliomas, antibodies against cytokeratins 5/6, S 100 protein and vimentin produced the most consistent reactivity profile. Staining for cytokeratins 5/6 is a useful addition to the established immunohistologic marker panel in the work-up of myoepitheliomas, because of its reliable expression in most cases and because it may underline the epithelial nature of the lesion. Comparative genomic hybridisation (CGH) profiles of myoepitheliomas and myoepithelial carcinomas showed no chromosomal aberration in less than 50% of myoepithelial carcinomas, so that CGH is of limited help in a given case. In a case that was represented in three separately localized manifestations of the disease that differed in their CGH profiles, gross genetic aberrations suggest to be acquired during tumor progression and should raise the suspicion of malignancy. Thus, diagnosis of myoepithelial tumors of salivary glands has to rest on morphological grounds with support of a restricted panel of immunohistologic markers.

Speichelgangkarzinome

This tutorial focuses on salivary duct carcinoma (SDC), a rare, high grade neoplasm mainly of major salivary glands. The clinical course of these tumors is characterised by extended local disease, early distant metastasis, and poor outcome. The morphology of SDC is reminiscent of breast ductal carcinomas and may occasionally cause diagnostic problems. In spite of mimicry with ductal carcinoma in situ of the breast and an in situ component, that is evident in most tumors by immunohistology with antibodies directed against high molecular weight cytokeratins (Ck), SDC is always an invasive carcinoma. By immunohistology, most tumors show reactivity with antibodies directed against Ck 7, Ck 8/18 and Ck 19 whereas a morphologically indistinguishable subgroup expresses Ck 5/6 in tumor cells in addition to residual basal epithelia. Carcinoembryonic antigen, GCDFP-15 and androgen receptor are other helpful markers in routine diagnosis of SDC. Prostate-specific antigen is detectable in some cases. Abnormal p53 expression seems to indicate an adverse prognosis. Expression of c-erbB2, the over-expression of which is associated with a poor prognosis, may form the basis for a targeted therapeutic approach for selected cases of SDC.

Diagnostische Mammographie und Sonographie: Korrelation von diagnostischer BI-RADS-Einstufung mit dem histologischen und klinischen Endbefund

PURPOSE

The purpose of the study was to assess the final clinical outcome of BI-RADS Categories for diagnostic mammography and sonography.

MATERIAL AND METHODS

We analysed 632 mammography and sonography examinations from women with diagnostic indications (age: 23 - 100, mean 58) performed during 2001 and 2003. All patients received mammography and sonography examinations at different outside facilities and all patients received an additional sonography examination at the university radiology department and if necessary supplemental mammographic views. Final clinical outcome (Histology: 554; follow-up: 78) was ascertained in each case and concordance of BI-RADS-categories for mammography and sonography and final diagnosis were analysed.

RESULTS

Final diagnosis yielded 230 benign lesions (36 %) and 402 cancers (64 %). Concordance of BI-RADS Assessment and final outcome was documented in 542 cases (86 %). There were 11 correct category 1 and 2 assessments (2 %). 142 lesions were classified with BI-RADS 3 (22 %) with 5 false negative ratings. There were 264 category 4 lesions (42 %) with a PPV for a malignant lesion of 71 % (187/264) and finally 215 BI-RADS 5 lesions with a PPV of 98 % (210/215). Overall sensitivity of mammography was 92 % with specificity of 75 % and for sonography 86 % and 76 %. Mammography had a significantly higher detection rate for malignant lesions than sonography. The highest correlation between BI-RADS category and final outcome was documented for the diagnostic combination of mammography and sonography with a kappa-value of 0.817 (p < 0.001), followed by mammography (kappa: 0.684) and sonography (kappa: 0.631). The overall correlation was 0.681 (p < 0.001).

CONCLUSION

BI-RADS assessments of diagnostic mammography and sonography yields in a high cancer detection rate with a justifiable part of false positive ratings.

[Differential diagnosis of basaloid salivary gland tumors]

The diagnosis of basaloid tumors of the salivary glands can be challenging. In most cases, conventional histologic examination, if carried out meticulously, will be sufficient. Yet, immunohistochemistry will be of help for the definition of purely myoepithelial tumors, basaloid squamous cell carcinomas, and canalicular adenomas. The differential diagnosis of canalicular adenoma, basal cell adenoma and basal cell adenocarcinoma, adenoid cystic carcinoma, polymorphous low-grade adenocarcinoma, myoepithelial tumors, epithelial-myoepithelial carcinoma, and basaloid squamous cell carcinoma is discussed.

Oral lichen planus in patients with chronic liver diseases

BACKGROUND

The possible increased risk of oral lichen planus (OLP) in patients with chronic liver diseases is a controversial issue.

PATIENTS AND METHODS

We investigated a total of 156 outpatients with known liver diseases for occurrence of OLP. Hepatitis C virus (HCV) infection was proven for 117 patients (75%) and hepatitis B virus (HBV) infection for 16 patients (10.3%). Four patients were coinfected with HCV and HBV. An alcohol-derived hepatic cirrhosis was found in 23 patients (14.7%). Three patients had a biliary cirrhosis and one had a primary sclerosing cholangitis. Patients suspected of having OLP were transferred to the Department of Oral and Maxillofacial Surgery where excisional biopsies were taken.

RESULTS

Eight patients had a white alteration of the oral mucosa. OLP was suspected in five of them and was confirmed histologically in four. The alteration of the fifth patient disappeared during continued interferon therapy.

CONCLUSION

Our results show that there is no increased prevalence of OLP manifestation in patients suffering from HCV infection.

[Salivary gland tumors--tumor typing and grading]

In addition to staging, histological typing and grading provide important information for prognosis and adequate treatment of salivary gland cancers. Current classification and grading systems for mucoepidermoid carcinoma, adenoid cystic carcinoma, and malignant mixed tumor (carcinoma ex pleomorphic adenoma) are discussed.

Translocations t(11;18)(q21;q21) and t(14;18)(q32;q21) are the main chromosomal abnormalities involving MLT/MALT1 in MALT lymphomas

The recently discovered MLT/MALT1 gene is fused with the API2 gene in the t(11;18)(q21;q21), which characterizes about one-third of MALT lymphomas. In order to screen for variant translocations and amplifications of MLT/MALT1, we have developed a novel, undirected two-color interphase fluorescence in situ hybridization (FISH) assay with two PAC clones flanking MLT/MALT1. This assay was applied to 108 marginal zone B-cell lymphomas (MZBCLs), including 72 extranodal MALT lymphomas, 17 nodal, and 19 splenic MZBCL. In 19 MALT lymphomas (26%), but in none of the nodal or splenic MZBCL, separated hybridization signals of the MLT/MALT1 flanking probes, were found. Further FISH analyses showed that 12 of these 19 cases displayed the classical t(11;18) and the remaining seven cases revealed the novel t(14;18)(q32;q21), involving the MLT/MALT1 and IGH genes. The frequency at which these translocations occurred varied significantly with the primary location of disease. The t(11;18) was mainly detected in gastrointestinal MALT lymphomas, whereas the t(14;18) occurred in MALT lymphomas of the parotid gland and the conjunctiva. Amplification of MLT/MALT1 was not observed in any of the lymphomas analyzed. We conclude that the translocations t(11;18)(q21;q21) and t(14;18)(q21;q32) represent the main structural aberrations involving MLT/MALT1 in MALT lymphomas, whereas true amplifications of MLT/MALT1 occur rarely in MZBCL.

PTEN expression in breast and endometrial cancer: correlations with steroid hormone receptor status

OBJECTIVE

The PTEN (MMAC1/TEP1) tumor suppressor gene is frequently mutated and homozygously deleted in human neoplasms, but there is only sparse information about PTEN protein expression in hormone-dependent female tumors. Therefore, we investigated PTEN expression in 68 breast and 43 endometrial carcinomas.

METHODS

For PTEN protein detection, we used Western blot analysis followed by densitometry and compared these data with clinicopathologic parameters, the estrogen receptor (ER) and progesterone receptor (PR) status, HER2/neu and the proliferation marker Ki67.

RESULTS

We were able to show significantly decreased PTEN protein expression in endometrial carcinomas compared with normal endometrial tissue samples, especially in the endometrioid histological subtype. In contrast, PTEN downregulation was found more rarely in breast cancer. Lower PTEN expression in breast cancer correlated significantly with high ER immunoreactivity (p = 0.008) and was weakly associated with PR expression (p = 0.055) and low histological grading (p = 0.081). No correlation with any of these parameters was observed in endometrial tumors. In both tumor types, no association of PTEN expression with any other analyzed parameter was found.

CONCLUSIONS

These results suggest that PTEN expression plays different roles in the pathogenesis of endometrial carcinomas and breast cancer. In mammary carcinomas, loss of PTEN expression is mainly found in more differentiated tumors and is probably not a major event in carcinogenesis.

Overexpression of the p16 cell cycle inhibitor in breast cancer is associated with a more malignant phenotype

In order to study the role of the p16INK4A(MTS1/CDKN2a) tumor suppressor in breast cancer, we analyzed p16 protein expression in 60 breast cancer samples which were also analyzed for expression of Rb, Ki67, HER2/neu, and estrogen and progesterone receptors (ER, PR). P16 expression was investigated by two methods: western blotting (WB) followed by densitometry, and immunohistochemistry (IHC). The Rb status was studied by western blotting, and expression of Ki67, HER2/neu, ER, and PR was analyzed immunohistochemically. P16-negative results were found in 18% of the carcinomas by WB, but in only one case by IHC and were not associated with established prognostic parameters. In contrast, p16 overexpression which was detected by WB and IHC in 15% and 25% of the tumors, respectively, was significantly associated with unfavorable prognostic indicators. High p16 expression as detected by both methods correlated significantly with high grading and a negative estrogen receptor status. In addition, a significant association of p16 staining with inverse progesterone receptor status and high Ki67 expression was found with IHC. No correlation of p16 expression with clinical stage, HER2/neu immunostaining, Rb expression or Rb phosphorylation was found. Comparison of western blot results and immunohistochemistry suggests that both nuclear and cytoplasmic immunoreactivity in tumor cells is specific and due to p16 expression. We conclude that high p16 reactivity (both nuclear andcytoplasmic) is indicative of a more undifferentiated, malignant phenotype in mammary carcinomas.

Alterations of INK4a(p16-p14ARF)/INK4b(p15) expression and telomerase activation in meningioma progression

Dysregulation of cell cycle progression and telomerase activation have been implicated in malignant tumor progression as well as in the evasion of senescence and immortalization. We have investigated expression of the cell cycle control and tumor suppressor genes INK4a(p16-p14ARF), INK4b(p15-p10) and RB, and their relation to telomerase activation during malignant meningioma progression. 7/26 (27%) benign, 3/12 (25%) atypical but 4/7 (57%) anaplastic tumors lacked both, p16 and p15 protein expression. 14/39 (36%) benign and atypical but 5/7 (71%) anaplastic meningiomas contained no p14ARF mRNA. 2/46 (4%) tumors failed to express pRB. We observed frequent differential loss of expression of the alternatively spliced INK4a tumor suppressors p16 and p14ARF. Exclusive expression of the alternative INK4b transcript p10 possibly at the expense of p15 and therefore resulting in loss of p15 tumor suppressor activity was noted in two meningiomas. We have previously described telomerase activity or expression of the telomerase catalytic subunit hTERT in this meningioma series. Telomerase activation was detected in 10/27 (37%) benign, but 18/19 (95%) non-benign meningiomas. We observed no significant overall correlation between loss of INK4a/INK4b expression and telomerase activation. In conclusion, our results suggest a greater role for losses of INK4a/INK4b gene products in meningioma formation and malignant progression than previously thought. Inactivation of p16/p15- and pl4ARF-dependent pathways possibly in conjunction with telomerase activation might be critical steps for a meningioma cell towards escape from senescence, that is, immortalization.

Frequent p16/MTS1 inactivation in early stages of urothelial carcinoma of the bladder is not associated with tumor recurrence

OBJECTIVE

p16, located at chromosome 9p21, is a negative regulator of G1 cell checkpoint and functions as tumor suppressor gene. Only few data are available on the frequency and clinical relevance of p16 alterations in Ta, T1 transitional cell carcinoma (TCC) of the bladder. We investigated 40 patients with Ta, T1 TCC of the bladder for p16 alterations (mutations, homozygote deletions, allelic loss) or reduced p16 immunoreaction.

PATIENTS AND METHODS

DNA was prepared from microdissected tumor tissue from 40 patients with pTa, pT1 TCC of the bladder (pTa: 18 patients; pT1: 22 patients; grade 1: 7 patients; grade 2: 28 patients; grade 3: 5 patients). Mutation screening was performed using polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP) and direct sequencing at exon 1 and exon 2. Detection of homozygote deletions was performed using multiplex PCR. Immunohistochemistry (IHC) was performed using an anti-human monoclonal antibody (p16, Pharmingen). Allelic loss was detected by PCR using three different microsatellite markers (D9S161, D9S171, D9S319).

RESULTS

SSCP and direct sequencing revealed 3 cases of base substitution which turned out to be natural polymorphisms. Homozygote deletions were not detected in any case. p16 IHC revealed reduced p16 expression (<5% positive nuclei) in 10 patients; 30 patients had a positive reaction (> or =5% positive nuclei) and 10 patients a strong positive reaction (> or =50% positive nuclei). Thirteen of 37 informative cases revealed loss of heterozygosity (LOH) with at least one marker. After a median follow-up of 23 months, 15 patients suffered from disease recurrence. Statistical analysis using Kaplan-Meier analysis and the log-rank test did not reveal significant association of recurrence-free interval and detection of LOH (p = 0.34) or p16 IHC (p = 0.9).

CONCLUSIONS

We present a comprehensive evaluation of chromosome 9p21 alterations including p16 analysis and clinical follow-up data. Although p16 mutations and homozygote deletions are rarely detectable in Ta, T1 TCC, the reduction of p16 expression and the frequent hemizygote deletions at 9p21 suggest an early involvement of chromosome 9p and p16 in superficial TCC.

The glucocorticoid receptor is specifically expressed in the stromal compartment of the human endometrium

The human endometrium is a classical target tissue for steroid hormones. While the expression pattern and functional roles of both the estrogen receptor (ER) and the progesterone receptor (PR) are well defined, expression of the glucocorticoid receptor (GR) in this tissue has not been described so far. In the present study, we used immunohistochemistry to analyze the expression of GR in the normal human endometrium throughout the menstrual cycle. The expression of GR was compared to that of ER and PR, which were analyzed in parallel. We show that GR is expressed in the human endometrium with a pattern that markedly differs from the expression patterns of ER and PR. ER and PR are expressed in the nuclei of endometrial glands, whereas GR is completely absent from these structures. However, GR is strongly expressed in the stromal compartment of the endometrium throughout the cycle. Both stromal fibroblasts and lymphocytes are GR-positive. In addition GR expression is also observed in the endothelium of small endometrial blood vessels, which are ER- and PR-negative. Western blot analysis performed on endometrial tumor cell lines of glandular (HEC-1B) and mesodermal (SKUT-1B) origin, respectively, showed GR expression only in the latter. In summary, we demonstrate that GR is expressed in fibroblasts, lymphocytes and endothelial cells of the human endometrial stroma, while it is absent from the glandular compartment. The specific expression pattern of GR within the human endometrium points to a possible functional role of glucocorticoids in the process of decidualization which occurs primarily in the stromal compartment.

MAGE-A gene expression pattern in primary breast cancer

Melanoma antigen (MAGE)-A-derived peptides elicit a strong in vitro T-cell response against tumor cells. For determination of MAGE-A1, -2, -3, -4, -6, and -12 expression profile in invasive breast cancer, we developed a multiplex seminested reverse transcription-PCR-method. In total, 18 of 67 (27%) tumors were positive for at least one of these MAGE transcripts, and the expression pattern was heterogeneous: MAGE-A1 was positive in 4 of 67 (6%), MAGE-A2 in 13 of 67 (19%), MAGE-A3 in 7 of 67 (10%), MAGE-A4 in 9 of 67 (13%), MAGE-A6 in 10 of 67 (15%), and MAGE-A12 in 6 of 67 (9%) patients. The MAGE-A transcripts were more frequently expressed in ductal breast carcinomas compared with other histomorphological types. We observed a preferential expression of MAGE-A in patients at a higher risk of recurrence: those harboring tumors with high levels of the protease urokinase-type plasminogen activator and its inhibitor plasminogen activator inhibitor 1, high score of the Ki-67 proliferation antigen, and lesser degree of differentiation. Our findings suggests a potential involvement of MAGE-A in tumor progression, with potential implications for active immunotherapy.

Expression pattern of the AP-1 family in endometrial cancer: correlations with cell cycle regulators

PURPOSE

To study the expression pattern and the role of the AP-1 (activating protein-1) family of transcription factors in endometrial carcinogenesis.

METHODS

We performed Western blot experiments with specific antibodies for each of the AP-1 proteins (c-jun, junB, junD, c-fos, fosB, fra-1, fra-2) with 41 endometrial carcinomas. Expression levels of the AP-1 factors were correlated with clinico-pathologic tumor parameters, steroid receptor status, Ki-67 expression and the expression levels of eight cell cycle regulatory proteins (cyclin D1, cyclin E, cyclin B1, cdk2, cdk4, p16, p21, and Rb).

RESULTS

Of the seven AP-1 factors, three (c-fos, fra2, and junB) clearly showed higher expression levels in tumors when compared to matched normal endometrial samples. These factors also correlated significantly with cell cycle promoters (c-fos with cyclin E, cyclin B1, cdk2, and cdk4; fra-2 with cyclin B1; and junB with cyclin D1). Furthermore, high c-fos expression correlated with low ER and PR immunoreactivity and high grading (G3). On the other hand, correlations with classic cell cycle inhibitors (Rb, p16, p21) have also been observed for all AP-1 factors except c-jun and junD.

CONCLUSIONS

Our results indicate that the AP-1 family of transcription factors is probably implicated in the regulation of cell cycle progression and control in endometrial carcinomas. In particular, c-fos might be an additional negative prognostic factor and/or implicated in tumor progression in endometrial cancer.

Expression of cell-cycle regulatory proteins in endometrial carcinomas: correlations with hormone receptor status and clinicopathologic parameters

PURPOSE

The normal human endometrium is characterized by hormone-dependent variations in the levels of cell-cycle regulatory proteins during the menstrual cycle. As this tightly controlled system is disturbed in endometrial carcinomas, we analyzed which cell-cycle regulators are involved in endometrial carcinogenesis.

METHODS

We performed Western blot analysis of five cell-cycle stimulating (cyclins D1, E, B1, cdk2, cdk4) and three cell-cycle inhibiting (p16(INK4a), p21(WAF1), Rb) proteins in 41 endometrial carcinoma specimens. In addition, expression of the estrogen and progesterone receptors (ER, PR), Ki67, and, in selected cases, p16, cyclin E, and cyclin B1 was studied by immunohistochemistry.

RESULTS

We found upregulation of all analyzed cell-cycle regulators in most tumors compared to normal endometrial tissue samples. Overexpression of cyclin E, cyclin B1, and p21 was associated with a less differentiated phenotype. In addition, high levels of cyclin E, cdk2, and cdk4 correlated with weak/absent ER expression, and p16 and p21 overexpression was significantly associated with low PR immunoreactivity. Cyclin B1 expression correlated with cyclin E, cdk2, cdk4, p21, Rb, and Ki67, and cyclin E expression with cyclin D1 and Rb.

CONCLUSIONS

We conclude that cyclin E and cyclin B1 might be the major cell-cycle regulators involved in proliferation and reduced differentiation of endometrial carcinomas. In addition, p16, p21, and Rb appear to be uncoupled from their normal cell-cycle inhibiting function in many endometrial carcinomas.

[About the prognostic value of Her-2 gene-amplification and cell-proliferation in salivary duct carcinoma of the major salivary glands - a pilot-study]

INTRODUCTION

The salivary duct carcinoma (sdc) represents a rare variant of the group of adeno-carcinomas of the salivary glands. Histopathologically, it is marked by solid and cribriform cell nests with central necrosis, displaying distinct similarity with the ductal carcinoma of the breast, where prognosis can be correlated with Her-2 gene-amplification. Based on this histopathological similarity, the prognostic value of Her-2 gene amplification in SDC was examined in the presented pilot-study.

PATIENTS AND METHODS

Four own patients with different clinical courses were examined in regard to their histopathological features, Her-2 gene-amplification and proliferation (Ki67).

RESULTS

Three of the four patients died tumor related 2.4, 5.5 and 8.2 years after initial diagnosis. The remaining patient died tumor-free 6 year after diagnosis (myocardial infarct). The two patients with an early recurrent disease and distant metastasis showed a high Her-2 expression and proliferation (Ki67), compared to the other two patients.

CONCLUSION

In the presented pilot-study a distinct correlation between Her2-gene-amplification, proliferation (Ki67) and clinical course could be observed. Additional analysis to evaluate this aspect seems rectified, especially under recognition of therapy decisions.

Expression of Rb2/p130 in breast and endometrial cancer: correlations with hormone receptor status

Rb2/p130 is a member of the retinoblastoma family of proteins, consisting of Rb, Rb2 and p107, which are important negative regulators of cell cycle progression and differentiation. While Rb2 downregulation was observed in several malignant tumours including endometrial cancer, the role of p130 in breast carcinomas is still unknown. We investigated Rb2 protein expression in tumour tissue from 68 mammary and 41 endometrial carcinomas, 4 mammary cell lines, and normal tissue samples. Therefore, we performed Western blot experiments for Rb2, Rb, and the oestrogen and progesterone receptors (ER, PR-A, PR-B). Weak or absent Rb2 expression was more often found in endometrial (59%) than in mammary carcinomas (24%). We found significant positive correlations of Rb2 expression with Rb, ER, and PR-B in breast cancer samples, and of Rb2 with Rb, PR-A, PR-B, and younger age in endometrial carcinomas. No significant associations with histological grading, stage, nodal involvement, or Ki67 staining were detected. Rb2 mRNA expression was studied by semi-quantitative RT-PCR in 56 endometrial or mammary tissue samples and correlated significantly with Western blot results. Our results indicate that loss of Rb2 expression, mostly by transcriptional down-regulation, may be associated with the development and dedifferentiation of most endometrial and a subset of mammary carcinomas.

cis Interaction of the cell adhesion molecule CEACAM1 with integrin beta(3)

CEACAM1 is a cell adhesion molecule that has been implicated in a number of physiological processes (eg, tumor suppressor in epithelial tissues, potent angiogenic factor in microvessel formation, microbial receptor in human granulocytes and epithelial cells). The mechanism of CEACAM1 action is still largely unresolved but recent findings demonstrated that the cytoplasmic CEACAM1 domain is linked indirectly to the actin-based cytoskeleton. We have isolated integrin beta(3) as an associated protein using CEACAM1 tail affinity purification. This association depends on phosphorylation of Tyr-488 in the CEACAM1 cytoplasmic domain. Confocal laser scanning microscopy confirmed in vivo colocalization of both molecules in human granulocytes and epithelial cells. Furthermore, the concentrated colocalization at the tumor-stroma interface of invading melanoma masses suggests a functional role of CEACAM1-integrin beta(3) interaction in melanoma invasion. Moreover, colocalization of the two adhesion molecules is also found at the apical surface of glandular cells of pregnancy endometrium. Colocalization of CEACAM1 and integrin beta(3) at the transitional zone from proliferative to invasive extravillous trophoblast of the maternal-fetal interface supports a role for CEACAM1/integrin beta(3) complexes in cell invasion.

Expression of cyclin-dependent kinase inhibitors p16MTS1, p21WAF1, and p27KIP1 in HPV-positive and HPV-negative cervical adenocarcinomas

Inactivation or down-regulation of the cell-cycle inhibitors p16MTS1, p21WAF1, and p27KIP1 is involved in the carcinogenesis of various human tumors. In cervical squamous cell carcinomas that are associated with human papillomavirus (HPV) infection, the expression or function of these proteins is impaired by the action of viral oncoproteins E6 and E7. Comparably less is known about the role of these cyclin-dependent kinase inhibitors in cervical adenocarcinomas, 15-40% of which are HPV negative. Therefore, we studied the expression of p16MTS1, p21WAF1, and p27KIP1 by immunohistochemistry in 60 cervical adenocarcinomas. HPV infection was determined by PCR, and HPV 16 and 18 E6/E7 oncogene expression was analyzed by RNA-RNA in situ hybridization. We found significant correlations of strong p16 expression with HPV 16/18 infection and HPV 16/18 E6/E7 oncogene expression (P=0.001). Moderate or strong p16 expression was also observed in 41% of HPV-negative carcinomas, indicating that HPV-independent mechanisms might also lead to p16 overexpression. In addition, stronger p21 and p27 expression was significantly associated with the detection of HPV 16 or 18 E6/E7 transcripts (P=0.015 and 0.030, respectively). Obviously, the tumor suppressor action of these proteins can be overcome in HPV-positive lesions. In contrast, absent or low p16, p21, and p27 immunostaining was observed in most HPV-negative cervical adenocarcinomas and might contribute to carcinogenesis in these tumors.

Progesterone receptor isoforms, PR-B and PR-A, in breast cancer: correlations with clinicopathologic tumor parameters and expression of AP-1 factors

In the present study, we used Western blot analysis to determine the expression of the progesterone receptor (PR) isoforms, PR-B and PR-A, in breast tumors (n = 53), and correlated the expression patterns of the two isoforms with the clinicopathological parameters of these tumors and with expression of the AP-1 family of transcription factors. Expression of the two PR isoforms correlated significantly with each other, indicating that the expression of the two isoforms is probably regulated in a correlated fashion. Expression of both isoforms correlated significantly with expression of the estrogen receptor (ER). Furthermore, expression of PR-B was found to correlate significantly with the absence of ErbB2/neu. For the AP-1 factors, Fra-1 expression showed an inverse correlation with PR-B expression. In contrast, expression of FosB correlated significantly with expression of both isoforms, and the association was stronger with PR-B expression. An analysis of the ratio of expression of the two isoforms showed that most of the tumors expressed PR-A levels which were equal or higher than the corresponding PR-B expression levels (together 94% of the analyzed tumors) indicating that, in mammary carcinomas, a predominance of the PR-A isoform over the PR-B isoform seems to be the case. While there was no statistically significant correlation with age, staging and histological type, expression of both isoforms correlated with a more differentiated phenotype (G1/G2 grading). However, this association was stronger for PR-B. Also, a PR-A < or = PR-B expression level was associated with G1/G2 grading, while a PR-A > PR-B expression level showed an association with a more undifferentiated phenotype (G3 grading). The expression level of the two PR isoforms might prove to be of prognostic and/or predictive value, especially since the two isoforms have been shown to be functionally different and to modulate the response of tumor cells to progestins and antiprogestins differently.

Overexpression of the p16 cell cycle inhibitor in breast cancer is associated with a more malignant phenotype

In order to study the role of the p16INK4A(MTS1/CDKN2a) tumor suppressor in breast cancer, we analyzed p16 protein expression in 60 breast cancer samples which were also analyzed for expression of Rb, Ki67, HER2/neu, and estrogen and progesterone receptors (ER, PR). P16 expression was investigated by two methods: western blotting (WB) followed by densitometry, and immunohistochemistry (IHC). The Rb status was studied by western blotting, and expression of Ki67, HER2/neu, ER, and PR was analyzed immunohistochemically. P16-negative results were found in 18% of the carcinomas by WB, but in only one case by IHC and were not associated with established prognostic parameters. In contrast, p16 overexpression which was detected by WB and IHC in 15% and 25% of the tumors, respectively, was significantly associated with unfavorable prognostic indicators. High p16 expression as detected by both methods correlated significantly with high grading and a negative estrogen receptor status. In addition, a significant association of p16 staining with inverse progesterone receptor status and high Ki67 expression was found with IHC. No correlation of p16 expression with clinical stage, HER2/neu immunostaining, Rb expression or Rb phosphorylation was found. Comparison of western blot results and immunohistochemistry suggests that both nuclear and cytoplasmic immunoreactivity in tumor cells is specific and due to p16 expression. We conclude that high p16 reactivity (both nuclear andcytoplasmic) is indicative of a more undifferentiated, malignant phenotype in mammary carcinomas.

Relationship between telomerase activation and HPV 16/18 oncogene expression in squamous intraepithelial lesions and squamous cell carcinomas of the uterine cervix

SILs (squamous intraepithelial lesions) comprise a wide spectrum of clinically and biologically heterogeneous lesions ranging from benign proliferations to precancerous lesions. Telomerase activation plays a critical role in cellular immortalization and might be important for malignant progression. The viral oncogenes E6 and E7 are the principal transforming genes of high-risk HPVs and are important in HPV-associated immortalization and neoplastic transformation. In this study we investigated the relationship between telomerase activity, telomerase RNA, and HPV 16/18 oncogene expression in low- and high-grade SILs and SCCs (squamous cell carcinomas) of the cervix uteri. Telomerase activity was examined by the TRAP-assay and expression of the telomerase RNA (hTR) and HPV 16/18 E6/E7 oncogenes by RNA/RNA-in situ hybridization (ISH). The associated HPV-type was determined by PCR. Telomerase activity was observed in 25/29 (86%) SCCs, 31/41 (76%) high-grade SILs, 6/14 (43%) low-grade SILs, and 1/28 (3.6%) normal cervical tissues. Expression of hTR and viral oncogenes increased significantly with histopathologic severity of the lesion (p < 0.0001). A correlation was found between telomerase activity and intensity of viral oncogene expression. These findings suggest that telomerase activation occurs early in cervical carcinogenesis and is predominantly found in high-grade SILs and cervical SCCs. Our findings support current experimental data that suggest that telomerase is at least partially activated by viral oncogenes of high-risk HPV types. Telomerase activity with concomitant strong viral oncogene expression might therefore characterize a subset of lesions that are at risk for malignant progression.

Expression pattern of the adhesion molecule CEACAM1 (C-CAM, CD66a, BGP) in gestational trophoblastic lesions

CEACAM1 (CD66a, BGP, C-CAM) is an adhesion molecule of the carcinoembryonic antigen (CEA) family which has been shown to be normally expressed at the apical pole of epithelial cells and to show a dysregulated expression pattern in tumors derived from the latter. The purpose of the present study was to investigate the expression pattern of CEACAM1 in gestational trophoblastic lesions and to compare this expression with the one observed in the normal trophoblast. For this purpose, we performed immunohistochemistry using the 4D1/C2 monoclonal antibody which specifically recognizes CEACAM1 and does not interact with other members of the CEA family. Immunohistochemistry was performed on a total of 20 cases of gestational trophoblastic lesions including complete hydatidiform moles, one placental site trophoblastic nodule (PSN), one placental site trophoblastic tumor (PSTT), and three choriocarcinomas. Immunostaining for cytokeratin, hPL, hCG, and Ki-67 was also performed. Normal placental samples served as a control. CEACAM1 was absent from villous cyto- and syncytiotrophoblast in both normal placenta and hydatidiform molar samples. It was present in the benign extravillous trophoblast, with stronger expression in the proximal extravillous trophoblast of anchoring villi, but was also observed in interstitial and endovascular intermediate trophoblast and chorionic intermediate-like trophoblast. Partial expression was observed in the trophoblast proliferating from the surface of molar villi. In choriocarcinomas, areas of weak expression could be observed along with large areas without CEACAM1 expression. In the PSN and especially in the PSTT, CEACAM1 expression was stronger and more diffuse. The specific localization to extravillous trophoblast and its expression pattern in gestational trophoblastic lesions indicate that CEACAM1 can potentially be a helpful additional diagnostic marker in the differential diagnosis of such lesions.

Expression and tissue localization of soluble guanylyl cyclase in the human placenta using novel antibodies directed against the alpha(2) subunit

The cytoplasmic or soluble forms of guanylyl cyclase (sGC) are heme-containing heterodimeric enzymes that are regulated by nitric oxide (NO) and carbon monoxide (CO). These gaseous messenger molecules are produced in the human placenta and are potential regulators of vasodilation and trophoblast invasion. The alpha(2)-subunit of sGC has only recently been shown to naturally occur in placental extracts. In the present study, two novel antibodies directed against different epitopes of the alpha(2) subunit, were generated. Western Blot analysis confirmed the presence of a 82 kDa protein, identical with alpha(2) protein overexpressed in Sf9 cells. According to RNase protection analysis the alternatively spliced alpha(2i) variant was absent from human placenta. Immunohistochemical analysis showed the presence of alpha(2) protein in syncytiotrophoblast and villous and umbilical blood vessels, which are known sites of NO production. Strong expression was observed in the extravillous (intermediate) trophoblast, where the expression of CO-generating hemeoxygenases has recently been documented. Localization of alpha(2) subunit expression suggests a role for sGC in mediating the actions of both NO and CO. The novel antibodies characterized in the present study will be powerful tools to further elucidate the role of the NO/CO/cGMP signaling pathways in pathologic states such as preeclampsia and intrauterine growth retardation.

[Detection of p53 mutation in mouth mucosa smears of patients with oral squamous epithelial carcinoma]

Tumour-suppressor gene p53 encodes for an important cell-cycle regulatory protein and is therefore probably important for the development of many malignant diseases, e.g. squamous cell carcinoma of the mouth. This gene has mutated most frequently in connection with the development of cancer, so it has been well explored. Hence we chose it to find out whether swabs of the oral mucosa are suitable for supplying material for the detection of mutations in a gene that is connected with the development of oral squamous cell carcinomas, because swabs are easier to obtain than biopsies. We examined biopsies, swabs from the tumour, and swabs from mucosa that appeared healthy from 32 patients with oral squamous cell carcinoma and mucosal swabs from 35 healthy persons with polymerase chain reaction (PCR) and temperature gradient gel electrophoresis (TGGE). Fourteen of the 32 patients with a tumour showed mutations of p53, and in all cases the mutation could be demonstrated both in the biopsy and in the tumour swab. In four cases the mutation was also found in the swab of normal mucosa. Our investigations revealed that swabs are a suitable method for obtaining material for the detection of gene mutations in oral squamous cell carcinomas.

Differences in HPV 16- and HPV 18 E6/E7 oncogene expression between in situ and invasive adenocarcinomas of the cervix uteri

To evaluate the importance of high-risk human papillomavirus (HPV) types in in situ and invasive adeno- and adenosquamous carcinomas (ACISs/ACs, and ASCISs/ASCs) of the cervix uteri, we analyzed HPV infection and HPV 16- and HPV 18 E6/E7 oncogene expression in different histologic subtypes. Using the polymerase chain reaction (PCR) technique, 29 of 33 (88%) ACISs, 2 of 2 (100%) ASCISs, 46 of 54 (85%) ACs, and 8 of 10 (80%) ASCs were found to be HPV 16- and/or HPV 18-positive. In 25 of 35 (71%), 10 of 35 (29%), and 4 of 35 (11%) ACISs/ASCISs, HPV 16, HPV 18, and HPV 16 and HPV 18 were detected, respectively. Invasive ACs/ASCs were more frequently infected with HPV 18 (36 of 64, 56%) than with HPV 16 (28 of 64, 44%). Ten (16%) of these cases were positive for HPV 16 and HPV 18. In ACISs/ASCISs, HPV 16 oncogene expression predominated (62%) relative to HPV 18 (25%) expression, whereas in invasive ACs/ASCs, only 21% of the cases expressed HPV 16, but 48% of the cases expressed HPV 18 oncogenes. Thus, detection of HPV 18 in ACISs/ASCISs might be associated with an increased risk of progression. HPV oncogene expression was not dependent on histologic subtype of in situ or invasive AC. Normal glandular epithelia and glandular dysplasias (GDs, n = 4) were always negative concerning HPV oncogene expression. In HPV 16- and HPV 18-double-infected cases, HPV 18 oncogene expression was most frequently detected, and we did not find a coexpression of HPV 16- and HPV 18-specific oncogenes in purely glandular lesions or in cases with an additional CIN (cervical intraepithelial neoplasia) II or CIN III. HPV E6/E7 expression of the same HPV type in both in situ or invasive ACs and associated CIN II/III suggest that these lesions might be histogenetically related.

Leukemia inhibitory factor (LIF) stimulates the human HLA-G promoter in JEG3 choriocarcinoma cells

HLA-G is a non-classic class I MHC molecule specifically expressed by human invasive cytotrophoblast cells, which has been suggested to play a role in facilitating the immune tolerance of the conceptus. So far, very little is known about the regulation of the human HLA-G gene. The present study was, thus, designed to investigate the regulation of the human HLA-G promoter. JEG3 choriocarcinoma cells, which express HLA-G endogenously, were used as a model. A 890 bp fragment of the human HLA-G promoter was amplified by nested PCR from genomic DNA, cloned into pCR-Script and, after sequencing, subcloned into pGL3-Luc in front of the luciferase reporter gene. This vector was then used in transient transfection experiments in JEG3 cells. Parallel transfection experiments were performed using an alpha subunit (alphaSU)-Luc reporter plasmid as a control. Using this system, several potential modulating substances were tested in different concentrations and for different periods of time: phorbol ester (TPA), cAMP, IFNgamma, IL-1, and leukemia inhibitory factor (LIF), with only LIF administration resulting in induction of the HLA-G promoter. LIF treatment also resulted in induction of HLA-G mRNA. JEG3 cells are shown to possess LIF receptors. LIF is a pleiotropic cytokine produced at the maternal-fetal interface which has been shown to play an essential role in implantation in mice. LIF is produced in high amounts by the human endometrium and the trophoblast itself, and LIF receptors are present on cytotrophoblast cells. LIF could, thus, play a role in modulating HLA-G production and immune tolerance at the maternal-fetal interface.

Association of human papillomavirus infection with carcinoma of the cervix uteri and its precursor lesions: theoretical and practical implications

Human papillomaviruses (HPVs) are the major aetiological agents of cervical carcinoma. In this review, epidemiological and molecular data are combined to present a model for HPV-induced cervical carcinogenesis. The impact of current knowledge regarding diagnostic and therapeutic approaches is shown, i.e. the use of HPV tests in cervical cancer screening, in the management of atypical smears of uncertain diagnosis and in smears indicative of mild dysplasias, as well as in follow-up examinations during and after therapy. In addition, the value of the two most frequently used HPV detection systems, polymerase-chain reaction (PCR) and hybrid capture (HC) analysis, is discussed.

p53 tumour suppressor gene mutations in benign prostatic hyperplasia and prostate cancer

OBJECTIVES

To identify and analyse point mutations in p53 tumour suppressor gene (Tp53) in benign prostatic hyperplasia (BPH) by temperature gradient gel electrophoresis (TGGE) and sequence.

MATERIALS AND METHODS

141 tissue specimens (approx. 100 mg) after transurethral resection of the prostate (TURP), 12 specimens after needle biopsy. Control samples for genetic analysis were (a) 7 prostate tissues without any sign of BPH and malignancy and (b) 103 prostate cancer (PCa) tissues. DNA of the critical Tp53 exons 5-8 was amplified and run on horizontal polyacrylamide gels under defined temperature conditions (TGGE) to yield specific gel shifts and sets of homo- and heteroduplexes in case of mutation. Sequencing with a laser-fluorescent electrophoresis unit was done from re-amplified mutant and wild-type bands.

RESULTS

TGGE screening of 153 BPH samples identified 29 specimens with Tp53 mutations (5 in exon 5, 11 in exon 6, 12 in exon 7, 3 in exon 8; 1 tissue sample showed mutations in 3 exons at a time). The computed mutation frequency was 19.0%. Two patients, with mutation in BPH tissue, developed PCa 2-3 years after TURP. One patient with mutation in BPH tissue developed bladder cancer. Of 118 patients with non-mutated DNA in BPH, none is known to have a urological cancer. The Tp53 mutation frequency in 103 PCa samples was 26.2%. Significant differences of mutation frequency between BPH and PCa were detected only in lower exon 5 mutation counts in BPH.

CONCLUSION

Tp53 mutation in BPH tissue may be a tumour risk factor.

Expression of the MCP-1 gene and the HPV 16 E6/E7 oncogenes in squamous cell carcinomas of the cervix uteri and metastases

Monocyte chemoattractant protein 1 (MCP-1) plays an important role in the recruitment of monocytes in solid tumors. Previously, for cervical carcinoma cell lines an inverse correlation between the expression of the MCP-1 gene and the human papillomavirus (HPV) oncogenes E6/E7 was described. In this study paraffin-embedded biopsy specimens from 25 squamous cell carcinomas of the cervix uteri were analyzed for the expression of the MCP-1 gene and the HPV 16 E6/E7 oncogenes by RNA/RNA in situ hybridization. Similar to in vitro analyses, in our material a negative correlation between the transcription of these genes in tumor cells could be demonstrated in 19/25 cases, whereas in 6 cases both MCP-1 gene and HPV oncogene transcription could be detected. Interestingly, the same results regarding MCP-1 gene and HPV oncogene expression were observed in the majority of corresponding metastases. On the other hand, in stromal cells MCP-1-specific transcripts could be detected in all cases. In most of them intra- and/or peritumoral macrophages were observed. Our findings support the hypothesis that HPV oncoproteins are negative regulators of MCP-1 transcription.

Expression of cell cycle-regulatory proteins rb, p16/MTS1, p27/KIP1, p21/WAF1, cyclin D1 and cyclin E in breast cancer: correlations with expression of activating protein-1 family members

The activating protein-1 (AP-1) complex is a mitogen-activated composite transcription factor that leads to activation of various target genes and enhanced proliferation of many cells after stimulation by TPA, EGF, serum, etc. The molecular mechanism of cell-cycle activation by AP-1 complexes remains unclear. Therefore, we studied protein expression of 6 cell cycle-regulatory proteins (Rb, p16, p21, p27, cyclin D1, and cyclin E) in protein extracts from 53 breast cancer samples and 4 mammary cell lines and correlated the data with expression of the 7 AP-1 family members (c-jun, junB, junD, c-fos, fosB, fra-1, and fra-2) as determined in a previous study. After Western blot analysis, we found significant associations between members of both groups: whereas c-jun was associated with Rb expression (p = 0.002), strong junD and c-fos expression correlated with high cyclin E reactivity (p = 0.017 and p = 0.013, respectively). Over-expression of fosB was found mainly in tumors with strong Rb (p = 0.013) and weak p16 (p = 0.004) expression. Fra-1 expression was significantly associated with p16 and cyclin E over-expression, whereas fra-2 results correlated with both cyclin D1 and cyclin E. These results point to direct or indirect activation of some cell cycle-regulatory proteins by AP-1 complexes. In addition, our data suggest differential regulation of cell cycle-stimulating and -inhibiting factors depending on the abundance of single AP-1 family members.