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Query: UMLS:C0007097 (carcinoma)
 152,788 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of three hormonal agents with a different mechanism of action (tamoxifen [TAM], medroxyprogesterone acetate [MPA] and estradiol [E2]) on tumor growth, differentiation and oncogene expression were evaluated using the estrogen-receptor positive human breast carcinoma cell line MCF-7 transplanted into nude mice. In MCF-7 tumors treated with E2, tumor incidence, mean weight of tumors, 3H-thymidine labelling index, differentiation antigen HMFGM (human milk-fat globule membrane) and ras p21, c-myc, neu oncogene products, the level was significantly increased. On the other hand MPA suppressed all of them. TAM increased the level of c-myc expression and HMFGM antigen, but suppressed the others. This evidence indicates that E2 induces both proliferation and differentiation of MCF-7 tumor cells. MPA suppresses both proliferation and differentiation, and TAM induces differentiation and suppresses proliferation.
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PMID:Effects of tamoxifen, medroxyprogesterone acetate and estradiol on tumor growth and oncogene expression in MCF-7 breast cancer cell line transplanted into nude mice. 183 73

To prospectively assess the role of the MDR1 gene in breast carcinomas, MDR1 RNA levels of breast carcinoma specimens were determined by slot blot analysis. In 59 evaluable patients with primary breast carcinomas, MDR1 RNA levels of the carcinomas were negative in 54%, low in 29% and high in 17% of the patients. No differences in age, menopause status, oestrogen and progesterone receptor levels, tumour size, lymph node involvement and c-erbB-2/neu gene expression were observed between MDR1 RNA negative patients and MDR1 RNA positive patients.
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PMID:MDR1 gene expression and prognostic factors in primary breast carcinomas. 183 47

Six families of activated protooncogenes, ras, raf, fur, neu, jun and myc have so far been associated with human lung cancer. Human bronchial epithelial cells in vitro are being used to investigate the functional role of these specific oncogenes and growth regulatory genes in carcinogenesis and tumour progression. When transferred into normal human bronchial epithelial cells by the highly efficient protoplast fusion method, the v-Ha-ras oncogene initiates a cascade of events leading to decreased responsiveness of these cells to inducers of squamous differentiation, aneuploidy and, less frequently, 'immortality' and tumorigenicity with metastasis in athymic nude mice. Transfection of the SV40 T antigen gene results in nontumorigenic cell lines that have a nearly normal pathway of terminal squamous differentiation and can be transformed into malignant cells by transfected Ha-ras, N-ras or Ki-ras. The combination of transfected c-myc and c-raf-1 also transforms human bronchial epithelial cells into neoplastic cells that exhibit some phenotypic traits found in small-cell carcinomas. These and other results indicate that proto-oncogenes dysregulate the pathways of growth and differentiation of human bronchial epithelial cells and play an important role in human carcinogenesis. Analyses of allelic deletion and somatic cell hybrids are being used to identify the chromosomal localization of tumour suppressor genes. We have examined 54 non-small-cell bronchogenic carcinomas with 13 polymorphic markers. Loss of heterozygosity was more frequent than among 23 squamous-cell carcinomas than among 23 adenocarcinomas or eight large-cell carcinomas. Loss of heterozygosity for chromosome 17p was found in 89% of cases of squamous-cell carcinoma and 18% of adenocarcinomas. Analysis of chromosome 11 for allelic deletions revealed two commonly deleted regions (11p13 and 11p15.5). Somatic cell hybrids between normal human bronchial epithelial cells and Hut292DM, a lung carcinoma cell line, had a finite lifespan in vitro and were nontumorigenic in athymic nude mice. Tumour suppressive effects of individual or combinations of specific human chromosomes on Hut292DM are being examined by formation of microcell-cell hybrids. Chromosome 11 has tumour suppressor activity in these hybrids. Both of these studies suggest that tumour suppressor genes play a dominant role in lung carcinogenesis and provide in-vitro model systems for isolating these genes by subtraction library and insertional mutagenesis techniques.
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PMID:Role of oncogenes and tumour suppressor genes in human lung carcinogenesis. 185 68

Varying results have been reported on the role of neu oncogene in mammary carcinogenesis. In order to further address this issue, the activated neu oncogene was introduced into mammary epithelial cells in situ of both mammary carcinoma-susceptible Wistar Furth and resistant Copenhagen rats by infusing replication-defective recombinant retroviruses carrying the neu oncogene into the mammary gland lumen. At the highest virus titer tested, very high numbers of mammary carcinomas developed within 2 weeks in all exposed glands in both rat strains. When the virus titer was reduced, however, individual tumors occurred with varying latencies. In addition, not all of the neu-infected mammary cells progressed to form mammary carcinomas. These results suggest that while neu is a potent mammary transforming gene, either other events in addition to neu expression may be required for full malignant transformation or not all mammary ductal epithelial cells are able to be neoplastically transformed.
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PMID:Frequent induction of mammary carcinomas following neu oncogene transfer into in situ mammary epithelial cells of susceptible and resistant rat strains. 191 83

Non-small cell lung cancers (NSCLC) comprise 75% of all lung cancers and consist of three major histologic types: squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. The histopathology of lung cancer appears to be changing: The incidence of squamous cell carcinoma in the United States is declining, accompanied by the increase in the incidence of adenocarcinoma. Carcinoma of the lung is thought to arise from a pluripotent epithelial cell capable of expressing a variety of phenotypes. Malignant transformation is the end result of multiple events involving the growth control of bronchopulmonary epithelium. It is well known that squamous cell carcinomas are preceded by many years of progressive mucosal changes including squamous metaplasia, dysplasia, and carcinoma in situ. Premalignant changes associated with the other types of NSCLC are less well understood. Recently characterized markers for peripheral airway cell differentiation and selected monoclonal antibodies may be helpful. It is conceivable to identify specific genetic events at the cellular level using in situ hybridization or polymerase chain reaction. Biologic and genetic studies have renewed the awareness of the pleomorphism of NSCLC. Potentially interesting subsets include the following: (1) The expression of neuroendocrine (NE) markers has been demonstrated in selected NSCLC (NSCLC-NE), mostly in adeno- and large cell carcinomas. (2) The presence of K-ras mutations in surgically resected adenocarcinomas has been associated with shortened survival times. (3) Also, the neu gene encoded protein p185 has been associated with a more aggressive clinical course in adenocarcinomas. Further studies are needed to confirm such results and correlate the findings with the current WHO NSCLC classification. Rapid validation of relevant new diagnostic approaches is an enormous challenge. Although selected immunohistochemical and molecular biologic techniques may work on routinely processed paraffin-embedded material obtained from the pathology archives, many of the newest applications require fresh or freshly frozen specimens from large numbers of patients with a computerized clinical data base for adequate clinicopathologic correlations. Establishing such a resource is obviously a team effort requiring close collaboration of the oncologist, pathologist, surgeon, and technicians.
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PMID:Pathology of non-small cell lung cancer. New diagnostic approaches. 196 74

The neu protooncogene is a recently described transforming gene originally isolated from ethylnitrosourea-induced rat neuroblastomas. We have examined the expression of the neu gene in human non-small cell lung carcinomas using immunoprecipitation and immunohistochemistry. The neu protein product (p185neu) was present in eight of 22 non-small cell carcinoma cell lines derived from human lung tumors. Expression of p185neu was found in all histological subtypes of non-small cell carcinomas including large cell carcinomas, squamous cell carcinomas, and adenocarcinomas. Extension of these data to biopsy specimens of human lung tumors demonstrated that normal ciliated bronchial epithelium of the peripheral airways expressed p185neu at low levels. Neoplastic cells in four of 12 adenocarcinomas and three of five squamous cell carcinomas also expressed p185neu at levels higher than the normal ciliated bronchial epithelium. Together these studies indicate that p185neu expression is a common feature of human lung tumors.
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PMID:Expression of the neu gene-encoded protein (P185neu) in human non-small cell carcinomas of the lung. 196 24

The development of a consistent strategy for the analysis of oncogene expression at the cellular level is essential for understanding the roles of these genes in the development and progression of human neoplasia. Detection of the neu oncogene products in breast carcinoma was selected as a model for analysis of oncogene expression. Fifty-two primary human breast carcinomas were evaluated by quantitation of neu DNA amplification and mRNA expression and by localization of neu mRNA and protein (p 185) at the cellular level by in situ hybridization (ISH) and immunohistochemistry (IHC). The specificity and sensitivity of the molecular and immunologic probes for neu were established with the use of genetically engineered cell lines that overexpressed either neu or epidermal growth factor receptor (EGFR). Twenty-nine percent of breast carcinomas demonstrated neu DNA amplification and mRNA overexpression, and there was close correlation between the level of neu mRNA expression and detection of neu gene products by ISH and IHC. Thirty-two percent of carcinomas demonstrated neu mRNA overexpression by ISH. The immunohistochemical method using TA1 monoclonal antibody for p185 was exquisitely sensitive in acetone-fixed frozen sections and provided an excellent approach for judging overexpression as confirmed by the various molecular analyses. All areas of nonmalignant breast epithelium stained weakly, and a wide range of staining intensity was observed in malignant breast epithelium, with 31% of carcinomas judged to be p185 overexpressors. Heterogeneous expression of p185 was seen in some carcinomas. This study provides a strategic approach for the evaluation of oncogene expression in human tumors.
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PMID:Strategies for the analysis of oncogene overexpression. Studies of the neu oncogene in breast carcinoma. 219 80

p185neu is the protein product of the HER2/neu protooncogene. This protein has characteristics of a tyrosine kinase growth factor receptor and is postulated to be important in human carcinogenesis. To define the significance of the expression of this protein in human non-small cell lung cancer, 55 tumors from patients with squamous cell carcinoma (16), adenocarcinoma (29), or large cell carcinoma (10) of the lung were examined for p185neu using immunohistological methods. Five of 16 squamous cell carcinomas and 10 of 29 adenocarcinomas were found to overexpress p185neu relative to levels of expression seen in uninvolved bronchiolar epithelium. For the adenocarcinomas, p185neu expression was associated with older age (66.6 +/- 10.1 versus 57.5 +/- 10.8 years) (P = 0.04) and shortened survival (83.7 +/- 94.1 versus 188.5 +/- 120 weeks) (P = 0.01). In this group, using Cox's multivariate survival analysis, p185neu expression was found to be a significant determinant of survival (P = 0.04) even after accounting for the effect of tumor stage. For the squamous cell carcinomas, p185neu expression was not correlated with any of our clinicopathological parameters. Our findings indicate that non-small cell lung cancers which express p185neu do so at levels higher than that found in normal bronchiolar epithelium, and expression in adenocarcinomas of the lung is independently associated with diminished survival intervals.
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PMID:p185neu expression in human lung adenocarcinomas predicts shortened survival. 197 68

The c-erb B-2/neu gene encodes a cell-surface glycoprotein with extensive homology to, but distinct from, the epidermal growth-factor receptor. In this study, we compared the c-erb B-2/neu gene amplification and expression of tissue specimens obtained from the bladders of normal controls and patients with high-grade transitional cell bladder carcinoma. Southern blot analysis of DNAs from 24 patients and 5 controls showed 2 cases of c-erb B-2/neu gene amplification in patients and none in controls. Western blot analysis demonstrated that c-erb B-2/neu was expressed in 67.6% (23/34) of patient specimens but in none of the controls (0/5). This finding agreed with the result of immunohistochemical staining, which showed that tissue from 74.3% (26/35) of the patients and none of the controls (0/7) showed positive immunofluorescence staining. This is the first report suggesting that c-erb B-2/neu gene amplification may be associated with human bladder carcinogenesis.
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PMID:Amplification and expression of the c-erb B-2/neu proto-oncogene in human bladder cancer. 197 77

The erbB-1 and erbB-2 protooncogenes encode homologous membrane receptors that respectively bind epidermal growth factor (EGF) and a still incompletely characterized ligand. Binding of EGF to its receptor is known to increase tyrosine phosphorylation of the erbB-2/neu receptor in tumor cells. To investigate the mechanism of this transregulatory pathway, we analyzed the interactions between the two receptors in SKBR-3 human breast carcinoma cells. Chemical cross-linking of 125I-labeled EGF revealed that the radiolabeled EGF receptor coimmunoprecipitates with the erbB-2/neu receptor. In addition a cross-linked species of 360-kdalton molecular mass is also coimmunoprecipitated. The formation of the latter species is absolutely dependent on the presence of EGF receptor and thus appears to represent a heterodimer of the erbB-1 and erbB-2 receptors. In vitro kinase reaction assays revealed that receptor heterodimerization is induced by EGF binding and leads to a dramatic increase in the self-phosphorylation capacity of the dimerized receptors. Moreover, analysis of living SKBR-3 cells suggested that most of the EGF-induced transregulation of the erbB-2/neu receptor is due to receptor heterodimerization. In conclusion, heterodimers of erbB-1 and erbB-2 receptors may provide a mechanism for dual transductory functions of growth factors of breast tumor cells.
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PMID:Heterodimerization of the erbB-1 and erbB-2 receptors in human breast carcinoma cells: a mechanism for receptor transregulation. 198 Feb 16


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