Lesley Alpert

Identification of genes associated with head and neck carcinogenesis by cDNA microarray comparison between matched primary normal epithelial and squamous carcinoma cells.

In order to identify genes involved in head and neck carcinogenesis, we compared the gene expression profile in matched primary normal epithelial cells and primary head and neck cancer cells from the same patients. A cDNA microarray analysis consisting of 12 530 human genes revealed significant changes in the expression of 213 genes, with 91 genes being up-regulated and 122 being down-regulated. This comprehensive list of genes includes those associated with signal transduction (growth factors), cell structure, cell cycle, transcription, apoptosis, and cell–cell adhesion. Further analysis of nine genes involved in cell–cell interaction, using Western blot and/or reverse transcription (RT)–PCR of four paired cell lines supported the reliability of our microarray analysis. More specifically, our study provides the first evidence that claudin-7 and connexin 31.1 are down-regulated in head and neck squamous cell carcinomas (HNSCC) compared to normal cells. These findings provide a large body of information regarding gene expression profiles associated with head and neck carcinogenesis, and also represent a source of potential targets for HNSCC prevention and/or therapeutics.

Mutation analysis of SDHB and SDHC: novel germline mutations in sporadic head and neck paraganglioma and familial paraganglioma and/or pheochromocytoma

BackgroundGermline mutations of the SDHD, SDHB and SDHC genes, encoding three of the four subunits of succinate dehydrogenase, are a major cause of hereditary paraganglioma and pheochromocytoma, and demonstrate that these genes are classic tumor suppressors. Succinate dehydrogenase is a heterotetrameric protein complex and a component of both the Krebs cycle and the mitochondrial respiratory chain (succinate:ubiquinone oxidoreductase or complex II).MethodsUsing conformation sensitive gel electrophoresis (CSGE) and direct DNA sequencing to analyse genomic DNA from peripheral blood lymphocytes, here we describe the mutation analysis of the SDHB and SDHC genes in 37 patients with sporadic (i.e. no known family history) head and neck paraganglioma and five pheochromocytoma and/or paraganglioma families.ResultsTwo sporadic patients were found to have a SDHB splice site mutation in intron 4, c.423+1G>A, which produces a mis-spliced transcript with a 54 nucleotide deletion, resulting in an 18 amino acid in-frame deletion. A third patient was found to carry the c.214C>T (p.Arg72Cys) missense mutation in exon 4 of SDHC, which is situated in a highly conserved protein motif that constitutes the quinone-binding site of the succinate: ubiquinone oxidoreductase (SQR) complex in E. coli. Together with our previous results, we found 27 germline mutations of SDH genes in 95 cases (28%) of sporadic head and neck paraganglioma. In addition all index patients of five families showing hereditary pheochromocytoma-paraganglioma were found to carry germline mutations of SDHB: four of which were novel, c.343C>T (p.Arg115X), c.141G>A (p.Trp47X), c.281G>A (p.Arg94Lys), and c.653G>C (p.Trp218Ser), and one reported previously, c.136C>T, p.Arg46X.ConclusionIn conclusion, these data indicate that germline mutations of SDHB and SDHC play a minor role in sporadic head and neck paraganglioma and further underline the importance of germline SDHB mutations in cases of familial pheochromocytoma-paraganglioma.

E6/E7 proteins of HPV type 16 and ErbB-2 cooperate to induce neoplastic transformation of primary normal oral epithelial cells

Head and neck squamous cell carcinomas (HNSCC) are characterized by a marked propensity for local invasion and spread to cervical lymph nodes, with distant metastases developing in 30–40% of cases. HPV-16 is an important risk factor for HNSCC. How HPV enhances susceptibility to HNSCC is not fully understood, but seems to involve cofactors. In this study, we examined the effect of the cooperation between HPV-16 and the tyrosine kinase receptor ErbB-2 on E-cadherin/catenin complex patterns and neoplastic transformation of human normal oral epithelial (NOE) cells. We report that overexpression of ErbB-2 or E6/E7 alone does not affect E-cadherin/catenin complex patterns nor does it induce cell transformation of NOE cells. In contrast, coexpression of E6/E7 and ErbB-2 downregulates E-cadherin and catenin expression. This is accompanied by cytoplasmic localization of E-cadherin, as well as nuclear translocation of α, β, and γ-catenins. Furthermore, we demonstrate that E6/E7 cooperate with overexpressed ErbB-2 to induce tumor formation in nude mice and to upregulate cyclin D1 and c-myc expression. Our data suggest that E6/E7 cooperate with ErbB-2 in head and neck carcinogenesis, at least in part, via the conversion of β-catenin from a cell adhesion to a nuclear function, that is, to act as a potential transcriptional regulator. This conversion leads to the upregulation of cyclin D1, c-myc and other oncoproteins necessary for alteration of the E-cadherin/catenin complex and cell transformation of NOE cells.

Overexpression of cytochrome P-450 isoforms involved in aflatoxin B1 bioactivation in human liver with cirrhosis and hepatitis.

Studies were carried out to test the hypothesis that inflammatory liver disease increases the expression of specific cytochrome P-450 isoenzymes involved in aflatoxin B1 (AFB) activation. The immunohistochemical expression and localization of various human cytochrome P-450 isoforms, including CYP2A6, CYP1A2, CYP3A4, and CYP2B1, were examined in normal human liver and liver with hepatitis and cirrhosis. The constitutive expression of CYP3A4 in normal liver showed a characteristic pattern of distribution in centrilobular hepatocytes, whereas CYP1A2, CYP2A6, and CYP2B1 1 were expressed uniformly throughout the liver acinus. In sections of liver infected with hepatitis B virus (HBV) or hepatitis C virus (HCV), the expression of CYP2A6 was markedly increased in hepatocytes immediately adjacent to areas of fibrosis and inflammation. CYP3A4 and CYP2B 1 were induced to a lesser degree, and expression of CYP1A2 was unaffected. In HBV-infected liver, double immunostaining revealed that overexpression of CYP2A6 occurred in hepatocytes expressing the HBV core antigen. In HCV-infected liver, CYP2A6, CYP3A4, and CYP2B 1 were overexpressed in hepatocytes with hemosiderin pigmentation. These results suggest that alterations in phenotypic expression of specific P-450 isoenzymes in hepatocytes associated with hepatic inflammation and cirrhosis might increase susceptibility to AFB genotoxicity.

Overexpression of Estrogen Receptors in Columnar Cell Change and in Unfolding Breast Lobules

Abstract:  Columnar cell change (CCC) is common and has often been considered of little clinical interest. However, some investigators have suggested that it may be a marker for increased risk of breast cancer. To see whether CCC is subject to hormonal influences, the distribution of estrogen receptors (ER) was determined in a series of breast specimens showing this change. The cases came from 51 women age 35–80 years (mean 52 years) with the following associated findings: 27 carcinomas and 24 benign lesions. Consecutive sections were recut from the paraffin blocks: one was stained with hematoxylin‐eosin and the other was immunostained for ER. Since CCC is the initial step in unfolding of lobules, a process which can evolve into various conditions, including cyst formation and epithelial hyperplasia, the distribution of ER was also evaluated in the latter conditions. In normal lobules, only a minority of epithelial cells were reactive for ER. In contrast, the cells showing columnar change uniformly expressed strong nuclear reactivity. In lobules undergoing unfolding with the formation of cysts, the lining epithelial cells remained positive even when they became cuboidal or flattened. The pattern of reactivity differs in the two types of hyperplasia. In hyperplasia of the usual type, the pattern was heterogeneous, with a majority of negative cells mixed with cells showing varying degrees of positivity. In columnar cell hyperplasia, the stratified epithelium maintained a strong uniform positivity. It is now recognized that columnar cell lesions include a wide spectrum of changes reaching a point at the upper end where the differential diagnosis is ductal carcinoma in situ. Other studies have shown that advanced CCC lesions with various degrees of hyperplasia and/or atypia are ER positive. The present findings indicate that, from the initial stage of the spectrum, the common columnar cells are strongly ER positive. Moreover, the observation that the lining cells in cysts are positive supports the theory that hormonal factors are involved in the development of fibrocystic changes. 

Mixed ovarian germ cell tumor in a BRCA2 mutation carrier.

BRCA2 germ-line mutations confer an increased risk of developing breast and ovarian cancer. We report the occurrence of a mixed ovarian germ cell tumor (GCT) (50% embryonal carcinoma, 20%-25% choriocarcinoma, 10%-15% dysgerminoma, and 10%-15% immature teratoma) in a 33-year-old Ashkenazi Jewish woman, carrier of the BRCA2:6174delT mutation. The mutation is also present in the patients father, who was diagnosed with breast cancer at age 59 and with prostate cancer at age 69. This is the first report of a GCT in a BRCA2 mutation carrier; there was one previous report of an ovarian dysgerminoma in a BRCA1 carrier. Molecular analysis of the probands tumor DNA revealed there was no loss of heterozygosity of the wild-type allele in the tumor, as is usually the case for epithelial BRCA-related ovarian tumors. This suggests either that biallelic inactivation of BRCA2 is not required for GCT development or that this is a chance event unrelated to the presence of the mutation.

Peripheral biphasic adenocarcinoma of the lung: Light microscopic and immunohistochemical findings

We report two cases of peripheral biphasic adenocarcinoma primary in the lung. To our knowledge, peripheral adenocarcinoma of the lung with a spindle-cell component has not been described previously. Diffuse positive cytokeratin and negative vimentin immunostaining of the spindle-cell components support an epithelial differentiation of the malignant spindle cells. Although study of additional cases is needed, our initial findings suggest that immunohistochemical staining pattern may help distinguish these neoplasms from other biphasic neoplasms primary or secondary to the lung, such as carcinosarcoma or malignant mesothelioma.

Acute symptomatic gastritis due to Helicobacter heilmannii

Helicobacter heilmannii is a Gram‐negative spiral‐shaped organism predominantly associated with zoonotic infection. Human pathology has also been described, but acute symptoms with complete resolution have been infrequently reported. We present a 50‐year‐old man in whom H. heilmannii gastritis presented as an acute febrile illness and was successfully treated with antibiotics and proton pump inhibitor. Epidemiology, diagnosis, and treatment of similar cases are reviewed.