Immunoexpression of c-erbB-2 and p53 in benign and malignant salivary neoplasms with myoepithelial differentiation.

AIM: To evaluate whether the immunoexpression of c-erbB-2 and p53 is involved in the pathogenesis and progression of salivary tumours with myoepithelial differentiation. METHODS: 233 tumours from 211 patients were studied. These included 76 primary and 24 recurrent adenocarcinomas (polymorphous low grade adenocarcinoma, 13; epithelial-myoepithelial carcinoma, 19; adenoid cystic carcinoma, 56; and basal cell adenocarcinoma, 12) and 133 pleomorphic adenomas and myoepitheliomas, 96 being primary and the remaining recurrent tumours. All cases were formalin fixed and paraffin wax embedded. A StrepABC peroxidase method and polyclonal c-erbB-2 and p53 specific antisera were used. RESULTS: Cell membrane staining of c-erbB-2 was not found in any benign or malignant tumour. There was p53 protein accumulation in one primary and one recurrent pleomorphic adenoma and in 10 adenocarcinomas (polymorphous low grade adenocarcinoma, one; epithelial-myoepithelial carcinoma, one; adenoid cystic carcinoma, five; and basal cell adenocarcinoma, three), three of them being recurrences. CONCLUSIONS: The c-erbB-2 and p53 proteins are not involved in the pathogenesis of pleomorphic adenoma and myoepithelioma and do not constitute biomarkers in assessing the risk of recurrence. c-erbB-2 is not involved in the genesis of low grade salivary neoplasia with myoepithelial differentiation. The percentage of this type of neoplasia with p53 accumulation is low (10%) and does not appear to be related to tumour recurrence.     

MAGE-1, GAGE-1/-2 gene expression in FNAB of classic variant of papillary thyroid carcinoma and papillary hyperplasia in nodular goiter.

Differentiation of the papillary variant of papillary thyroid carcinoma (PTC) from papillary hyperplasia in nodular goiter may be difficult in fine-needle aspiration biopsy (FNAB) by means of morphology alone. To improve cytodiagnostic accuracy the occurrence of MAGE-1, GAGE-1/-2 gene expression was analyzed by means of RT-PCR. The genes investigated are recognized by autologous T lymphocytes and are expressed in carcinomas of various sites e.g. lung, ovary, colon but not in non-neoplastic tissue except testis. Routinely obtained smears with cytologic diagnosis of PTC confirmed by histology (n=20) and diagnosis of nodular goiter (n=10) were investigated. The MAGE-1, GAGE-1/-2 PCR products were found in 6/20 of the carcinomas but in none of the benign lesions. To identify PCR products automatic gene-sequencing in all positive cases was performed. The data indicate that MAGE-1, GAGE-1/-2 gene expression may give additional information to delineate PTC from papillary hyperplasia in FNAB.     

Distribution of epithelial membrane antigen in benign and malignant lesions of the salivary glands

Summary An antiserum against epithelial membrane antigen has been used to stain a variety of lesions arising in the salivary glands. In normal major and minor glands staining was localised to the ductal systems. There was no evidence of myoepithelial cell staining. The mucous elements of the submandibular and sublingual glands were negative, but in the mucous elements of the minor glands there was focal cytoplasmic positivity. There was no cytoplasmic staining of serous elements in major or minor salivary glands. In pleomorphic adenomas the luminal membrane of ductal elements was strongly positive, with focal cytoplasmic positivity in some myxoid areas. In mucoepidermoid tumours both adjacent cell membranes and cytoplasm were strongly positive. The ductal structure of adenoid cystic carcinomas were clearly delineated while the pseudoducts produced by enclosed areas of stroma were negative. All mesenchymally derived tumours were negative and a tumour previously considered as a chondroma was strongly positive. The results are discussed in relation to phenotypic heterogeneity and the histogenesis of salivary gland tumours.     

Intraductal papillary tumors of the major salivary glands: case reports of benign and malignant variants

Intraductal papilloma is an extremely rare benign salivary gland tumor that occurs most commonly in the minor salivary glands. To our knowledge, a malignant counterpart of intraductal papilloma has not been described previously. We report one case each of benign and malignant intraductal papillary tumors. The benign tumor occurred in the sublingual gland and was a typical example of intraductal papilloma, with the exception that we found no previously published reports of this type of tumor in this location. The other patient had a left parotid gland tumor that was architecturally similar to the intraductal papilloma, with the addition of cytologic atypia, intraductal extension, microinvasion, and lymph node metastases. This tumor was diagnosed as intraductal papillary adenocarcinoma with an invasive component. Both patients were alive and well without evidence of recurrence 2 years and 6 months (case 1) and 6 years (case 2) after surgery. Immunohistochemical examination revealed that the tumor cells resembled duct luminal cells in both cases. The 2 tumors had different immunoreactivities for carcinoembryonic antigen, p53, and Ki-67. The malignant counterpart of intraductal papilloma should be considered in the differential diagnosis of salivary gland tumors with a predominantly papillary structure, even though this tumor is extremely rare.     

Expression of the ERBB2 protein in benign and malignant salivary gland tumors.

Fifty-two primary human salivary gland tumors were analyzed for expression of the p185ERBB2 protein using immunohistochemical and immunoblotting techniques. About 63% (33/52) of the tumors expressed the ERBB2 protein. The highest expression levels were detected among the carcinomas, where 32% of the tumors showed intense membrane staining in 25-100% of the tumor cells. In benign pleomorphic adenomas, the corresponding figure was only 12%. Clinical follow-up data available for 18 of the 19 patients with carcinomas suggested an association between high ERBB2 protein levels and poor prognosis as measured by recurrence of disease and/or the appearance of metastases. These results indicate that ERBB2 activation and overexpression could be an important genetic event with possible prognostic implications in a subset of malignant salivary gland tumors.     

Immunohistological analysis of tumour growth factor beta 1 expression in normal and inflamed salivary glands.

AIM: To determine whether transforming growth factor-beta 1 (TGF-beta 1) has a pathogenetic role in disease of the salivary glands. METHODS: An indirect immunohistochemical technique was used to analyse TGF-beta 1 expression in six specimens of normal salivary gland and 23 surgical specimens. RESULTS: TGF-beta 1 was strongly expressed in the ductal epithelial cells of normal salivary gland tissues (six of six cases) and in inflammatory conditions (eight of 11 cases). In contrast, TGF-beta 1 was not detectable in ductal epithelial cells expressing HLA-DR around infiltrating CD4+ CD45RO+ activated T cells, in the salivary gland tissue of patients with Sjögren's syndrome. CONCLUSION: Because TGF-beta 1 has an essential role in the mucosal immunity of salivary glands, abnormal expression of this cytokine must be regarded as a candidate in the pathogenesis of Sjögren's syndrome.     

涎腺良恶性淋巴上皮病变中EB病毒DNA及其产物检测的意义

目的了解良恶性淋巴上皮性病变与埃泼斯坦－巴尔（ＥＢ）病毒的关系。方法采用原位杂交、聚合酶链反应（ＰＣＲ）及免疫组化ＬＳＡＢ法对涎腺１８例恶性淋巴上皮病变（ＭＬＥＬ）、１４例良性淋巴上皮病变（ＢＬＥＬ）进行ＥＢＶ编码的ＲＮＡ（ＥＢＥＲ１）、ＥＢＶＢａｍＨ１Ｗ片段及ＥＢＶ潜在膜蛋白（ＬＭＰ１）和潜在膜抗原（ＥＢＮＡ２）检测。结果（１）本组１８例ＭＬＥＬＥＢＥＲ１和ＥＢＶＢａｍＨ１Ｗ片段均为阳性，１４例ＢＬＥＬ则为阴性。（２）１８例ＭＬＥＬＬＭＰ１检出率７７．８％（１４／１８），ＥＢＮＡ２未检出（０／９）。（３）ＭＬＥＬ间质淋巴细胞多数为Ｔ细胞，ＢＬＥＬ间质多为Ｂ细胞。（４）本组统计２１６例涎腺癌中有３７例ＭＬＥＬ，发生率为１７．１％。结论本结果表明ＥＢＶ与ＭＬＥＬ存在密切关系，很可能在其发病中起着重要作用。文中还对ＢＬＥＬ与ＥＢＶ的关系、ＢＬＥＬ与ＭＬＥＬ的关系进行了讨论。     

Recurring loss involving chromosomes 1, 3, and 22 in malignant mesothelioma: possible sites of tumor suppressor genes

Cytogenetic analysis was performed on short-term cultures of primary tumor tissue obtained from five patients with pleural malignant mesothelioma. Clonal karyotypic abnormalities were detected in four patients, none of whom had received cytotoxic therapy prior to karyotypic evaluation. Recurring chromosomal changes included partial deletions of 1p and 3p, and monosomy of 18, 19, and 22. We also reviewed data on 24 previously reported pretreatment patients and determined that alterations of chromosomes 1, 3, and 22 are frequently associated with malignant mesothelioma. Partial loss of chromosome 1 due to deletions or other rearrangements most frequently involve bands 1p11-pter with the shortest region of overlap (SRO) occurring at 1p21-p22 in our patients. Deletions and other structural changes of chromosome 3 usually involve the region 3p14-p25. The SRO of 3p deletions appeared to be at band 3p21. Monosomy 22 represents the most consistent specific whole chromosome loss seen in malignant mesothelioma, being observed in 11 of 28 cases summarized. In addition, structural changes of 22q have been observed in three patients, and a breakpoint at 22q11 was reported in each case. Taken collectively, these data suggest that a cascade of events involving alterations of genes on more than one specific chromosome may play a critical role in the development of malignant mesothelioma. The pattern of recurring chromosomal loss, particularly of 1p, 3p, and 22q, indicates that these regions should be targeted for future molecular investigations into the possible involvement of suppressor genes in this malignancy.     

Genetic analysis of the human oncoprotein MDM2 in benign and malignant tumors of the salivary gland.

INTRODUCTION: Genetic alterations of oncogene MDM2 promote malignant transformation of several human tumors. In tumors of the salivary gland, however, the genetic status of MDM2 has not been evaluated so far. METHODS AND RESULTS: Benign and malignant tumors of the salivary gland (6 pleomorphic adenomas, 3 Warthin's tumors, 1 adenocarcinoma, 1 basal cell adenocarcinoma, 1 mucoepidermoid carcinoma, 3 acinic cell carcinomas, 2 adenoid cystic carcinoma, 1 squamous cell carcinoma) were analyzed by fluorescence-based PCR techniques and immunochemistry for MDM2 gene amplification, MDM2 gene expression, MDM2 gene mutation, MDM2 RNA splicing and MDM2 accumulation. Data show that all samples contained nonamplified MDM2 genes with nonmutant zinc finger regions. However, in two benign and two malignant samples, novel MDM2 mRNA splicing variant types 1 and 2 were detected. Furthermore, three malignant tumors revealed significant nuclear MDM2 accumulation. Correlation between levels of MDM2 mRNA and MDM2 protein could not be detected in the specimens. CONCLUSION: The present study suggests that MDM2 gene mutation and gene amplification do not contribute to MDM2 accumulation detected in malignant tumors of the salivary gland. However, the role of novel MDM2 splicing variants in MDM2 expression and malignant transformation must be elucidated further.     

Deregulated expression of p16INK4a and p53 pathway members in benign and malignant myoepithelial tumours of the salivary glands

Aims: Myoepithelial salivary gland tumours are uncommon and follow an unpredictable biological course. The aim was to examine their molecular background to acquire a better understanding of their clinical behaviour. Methods and results: Expression of protein (E2F1, p16^INK4a, p53, cyclin D1, Ki67 and Polycomb group proteins BMI‐1, MEL‐18 and EZH2) was investigated in 49 benign and 30 primary malignant myoepithelial tumours and five histologically benign recurrences by immunohistochemistry and the findings correlated with histopathological characteristics. Benign tumours showed a higher percentage of cells with expression of p16^INK4a pathway members [p16^INK4a and E2F1 (both P < 0.001), and cyclin D1, P = 0.002] compared with normal salivary gland. Furthermore, malignant tumours expressed p53 (P = 0.003) and EZH2 (P = 0.09) in a higher percentage. Recurrences displayed more p53 + tumour cells (P = 0.02) than benign primaries. Amongst the benign tumours, the clear cell type had the highest proliferation fraction (P = 0.05) and a higher percentage of EZH2 was detected in the plasmacytoid cell type (P = 0.002). Conclusions: This study is the first to demonstrate that deregulation of the p16^INK4a senescence pathway is involved in the development of myoepithelial tumours. We propose that additional inactivation of p53 in malignant primaries and benign recurrences contributes to myoepithelial neoplastic transformation and aggressive tumour growth.     

p53, c-erbB2, and PCNA status in benign, proliferative and malignant ovarian surface epithelial neoplasms: a study of 75 cases.

Low malignant potential tumors of the ovary are believed to behave in a manner intermediate to their benign and malignant counterparts. However, recent evidence suggests these lesions are in fact benign and better classified as proliferative. Based on our previous work and evaluating p53, c-erbB2, and PCNA status in a full spectrum of ovarian surface epithelial tumors, with emphasis on low malignant potential tumors, we tested this hypothesis. Immunohistochemical stains with monoclonal antibodies were used on 75 archival ovarian neoplasms. The results demonstrated anti-p53 reactivity in 30 carcinomas (40%), 2 of which were proliferative, and no reactivity in the benign tumors. Overexpression of c-erbB2 was seen in 31 malignant neoplasms (64.5%), 4 of which were proliferative (22.1%), and none in benign tumors. The PCNA proliferative index showed means of 42.8%, 22.8%, and 14.9% with benign, low malignant potential, and malignant tumors, respectively. Predicting immunoreactivity in carcinomas for anti-PCNA (Student t test), anti-p53, and anti-c-erbB2 (Pearson chi2 test) versus a lack of immunoreactivity in proliferative tumors indicate P values of .001, <.001, and <.001, respectively. These data show significant differences in the expression of these markers in ovarian tumors and suggest a possible role for these oncogenes as supplemental tools in diagnostic pathology. Further, our findings also support the designation of proliferative as opposed to the current nomenclature of low malignant potential tumors.     

Expression of BRCA1 protein in benign, borderline, and malignant epithelial ovarian neoplasms and its relationship to methylation and allelic loss of the BRCA1 gene

BRCA1 is a putative tumour suppressor gene responsible for a hereditary ovarian cancer syndrome. To clarify the possible involvement of BRCA1 in the development of sporadic ovarian neoplasms, this study analysed the immunohistochemical expression of BRCA1 protein in normal ovarian surface epithelium and 119 epithelial ovarian tumours (19 benign, 24 borderline, and 76 malignant tumours). Loss of heterozygosity (LOH) of BRCA1 was examined using three microsatellite markers to analyse the relationship between BRCA1 expression and alterations of the BRCA1 gene. Methylation of the BRCA1 promoter was also analysed by methylation-specific PCR. In ovarian carcinomas showing heterogeneous expression of BRCA1 protein in the same tumour, LOH and methylation status were analysed using microdissection techniques. Finally, the relationship of BRCA1 expression or its genetic alteration to clinicopathological parameters and patient survival was analysed. Ovarian surface epithelial cells expressed BRCA1 protein. Decreased expression of BRCA1 was found in 16% of benign tumours, 38% of borderline tumours, and 72% of carcinomas. LOH of BRCA1 was demonstrated in no benign tumours, 15% of borderline tumours, and 66% of carcinomas. Methylation of BRCA1 was not detected in benign or borderline tumours, but was present in 31% of carcinomas. Reduced expression of BRCA1 correlated with the presence of gene methylation. The frequency of BRCA1 methylation and LOH was higher in serous carcinomas than in other types. In one of the three serous carcinomas that showed heterogeneous expression of BRCA1, BRCA1-positive borderline-like tumour cells were LOH-positive and methylation-negative, whereas adjacent BRCA1-negative carcinoma cells were LOH-positive and methylation-positive. The prognosis of carcinoma patients did not correlate with BRCA1 expression or genetic status. These findings suggest that reduced expression of BRCA1 protein along with genetic and epigenetic changes of the BRCA1 gene play an important role in the development of sporadic ovarian carcinomas, particularly those of serous histology.