Survey of gene amplifications during prostate cancer progression by high-throughout fluorescence in situ hybridization on tissue microarrays.
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Prostate cancer development and progression is driven by the accumulation of genetic changes, the nature of which remains incompletely understood To facilitate high-throughput analysis of molecular events taking place in primary, recurrent, and metastat prostate cancer, we constructed a tissue microarray containing small 0.6-mm cylindrical samples acquired from 371 formalin-fixed blocks, including benign prostatic hyperplasia (n = 32) and primary tumors (n = 223), as well as both locally recurrent tumors (n = 54) and metastases (n = 62) from patients with hormone-refractory disease. Fluorescence in situ hybridization (FISH) was applied to the analysis of consecutive tissue microarray sections with probes for five different genes. High-level (> or =3X) amplifications were very rare (<2%) in primary prostate cancers However, in metastases from patients with hormone-refractory disease, amplification of the androgen receptor gene was seen in 22%, MYC in 11%, and Cyclin-D1 in 5% of the cases. In specimens from locally recurrent tumors, the corresponding percentages were 23, 4, and 8%. ERBB2 and NMYC amplifications were never detected at any stage of prostate cancer progression. In conclusion, FISH to tissue microarray sections enables high-throughput analysis of genetic alterations contributing to cancer development and progression. Our results implicate a role for amplification of androgen receptor in hormonal therapy failure and that of MYC in the metastatic progression of human prostate cancer. (+info)
Isolation and characterization of a new human breast cancer cell line, KPL-4, expressing the Erb B family receptors and interleukin-6.
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A new human breast cancer cell line, KPL-4, was recently isolated from the malignant pleural effusion of a breast cancer patient with an inflammatory skin metastasis. This cell line can be cultured under serum-free conditions and is tumorigenic in female athymic nude mice. Flow cytometric analysis revealed the expression of Erb B-1, -2 and -3. Dot blot hybridization showed a 15-fold amplification of the erb B-2. Reverse transcription-polymerase chain reaction analysis showed a detectable level of mRNA expression of all the Erb B family receptors. In addition, all the receptors were autophosphorylated under a serum-supplemented condition. Unexpectedly, transplanted KPL-4 tumours induced cachexia of recipient mice. A high concentration of interleukin-6 (IL-6) was detected in both the culture medium and the serum of mice. The weight of tumours significantly correlated with the serum IL-6 level. The antiproliferative effect of a humanized anti-Erb B-2 monoclonal antibody, rhuMAbHER2, was investigated. This antibody significantly inhibited the growth of KPL-4 cells in vitro but modestly in vivo. Loss of mouse body weight was partly reversed by rhuMAbHER2. These findings suggest that KPL-4 cells may be useful in the development of new strategies against breast cancer overexpressing the Erb B family receptors and against IL-6-induced cachexia. (+info)
Primary endometrioid carcinoma of fallopian tube. Clinicomorphologic study.
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Twenty cases of primary Fallopian tube endometrioid carcinoma (PFTEC) are presented in the paper. This accounts for 42.5% of all histologic forms of primary Fallopian tube carcinoma (PFTC) found in our Department. The youngest patient was 38, and the oldest 68 years (mean: 56 years). Seven patients were nulliparas. Only two cases were bilateral. According to FIGO staging, 13 cases were evaluated as stage I, 4 as II, and 3 as stage III. Due to the histologic grading, 8 tumors were classified as well, 7 as moderately, and 5 as poorly differentiated. In the time of preparation of the manuscript, 12 women were still alive, 2 of them with recurrent disease. The follow-up of patients without recurrence ranged from 4 to 120 months (median: 63). Eight patients had died (survival time: from 4 to 65 months; median: 26). Metastases were found in 8 patients, especially to ovaries. In 14/20 cases of PFTEC various forms of tubal wall invasion were observed. Blood or lymphatic vessels involvement was found in 9 patients. Six of them had died and one is alive with the symptoms of disease. Immunohistochemical detection of the mutant form of p53 protein and oncogene product, c-erbB-2, was studied in 17 cases. Nine patients exhibited simultaneous p53 protein accumulation and c-erbB-2 expression. 2/9 of these patients are alive with recurrent tumors and 4/9 died. Endometrioid carcinoma of the Fallopian tube can be characterized by a tendency to superficial invasion of tubal wall and in a half of the cases by invasion of vessels. The majority of these tumors were diagnosed at an early stage tumors. (+info)
Oncogene alterations in carcinomas of the uterine cervix: overexpression of the epidermal growth factor receptor is associated with poor prognosis.
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The involvement of human papillomavirus (HPV) in the development of carcinomas of the uterine cervix has been firmly established. However, other genetic alterations also play an important role in the pathogenesis of cervical cancer. Therefore, we have investigated the role of several (onco)genes in cervical carcinoma. In tumors from 136 patients with stage I and II cancer of the uterine cervix, the expression of epidermal growth factor receptor (EGFR), c-erbB-2/neu, p53, and murine double minute 2 (MDM-2) was studied using immunohistochemistry. In 32 cases, amplification of EGFR, c-erbB-2/neu, MDM-2, and c-myc was studied by Southern blot hybridization. The expression levels of these proteins were correlated with HPV positivity, International Federation of Gynecologists and Obstetricians stage, lymph node metastases, tumor diameter, vessel invasion, and disease-free and overall survival. Moderate/strong expression of EGFR was observed in 54% of tumors. c-erbB-2/neu was focally positive in 12 cases. p53 showed moderate/strong expression in 32% of the tumors. Thirteen % of tumors showed a moderate/strong expression of MDM-2, and this expression was correlated to p53 expression (P<0.001). Only moderate/strong expression of EGFR was associated with reduced disease-free (P = 0.002) and overall survival (P = 0.003). In multivariate analysis, the association of EGFR overexpression with poor prognosis was independent from lymph node status. Gene amplification was found for EGFR (four cases), c-erbB-2/ neu (two cases), and c-myc (six cases). In two tumors, rearrangement of c-myc was found, probably due to the integration of HPV. In conclusion, overexpression of the EGFR is an independent predictor for prognosis in earlier stages (stage I and II) of cervical cancer. p53 and MDM-2 expression are correlated to each other and may play a role in the interaction with HPV. The importance of c-erbB-2/neu and c-myc amplification is relatively small in stage I and II cervical cancer. (+info)
Localization of PS6K to chromosomal region 17q23 and determination of its amplification in breast cancer.
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The application of comparative genomic hybridization to the analysis of genetic abnormalities in breast carcinoma has consistently revealed that chromosome region 17q22-24 is a frequent site of gene amplification in this type of cancer. As part of an examination of expressed sequence tags for novel amplified genes in this region, we identified PS6K amplifications in both breast tumor tissues and cell lines. PS6K was localized to 17q23 and encodes a serine-threonine kinase whose activation is thought to regulate a wide array of cellular processes involved in the mitogenic response including protein synthesis, translation of specific mRNA species, and cell cycle progression from G1 to S phase. Northern and Western analyses revealed that amplification of this gene was accompanied by corresponding increases in mRNA and protein expression, respectively. These data represent the first determination of a gene amplification within 17q22-24 in breast cancer and suggest an oncogenic activity for PS6K. (+info)
The ErbB-2/HER2 oncoprotein of human carcinomas may function solely as a shared coreceptor for multiple stroma-derived growth factors.
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The erbB-2/HER2 oncogene is overexpressed in a significant fraction of human carcinomas of the breast, ovary, and lung in a manner that correlates with poor prognosis. Although the encoded protein resembles several receptors for growth factors, no high affinity ligand of ErbB-2 has so far been fully characterized. However, several lines of evidence have raised the possibility that ErbB-2 can augment signal transduction initiated by binding of certain growth factors to their direct receptors. Here, we contrasted these two models of ErbB-2 function: First, examination of a large series of epidermal growth factor (EGF)-like ligands and neuregulins, including virus-encoded ligands as well as related motifs derived from the precursor of EGF, failed to detect interactions with ErbB-2 when this protein was singly expressed. Second, by using antibodies that block inter-ErbB interactions and cells devoid of surface ErbB-2, we learned that signaling by all ligands examined, except those derived from the precursor of EGF, was enhanced by the oncoprotein. These results imply that ErbB-2 evolved as a shared receptor subunit of all ErbB-specific growth factors. Thus, oncogenicity of ErbB-2 in human epithelia may not rely on the existence of a specific ligand but rather on its ability to act as a coreceptor for multiple stroma-derived growth factors. (+info)
A novel gene (PLU-1) containing highly conserved putative DNA/chromatin binding motifs is specifically up-regulated in breast cancer.
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A novel human gene (PLU-1) has been identified which shows a highly restricted expression in normal adult tissues but which is consistently expressed in breast cancers. A fragment of the PLU-1 cDNA was identified by differentially screening a fetal brain library with cDNAs prepared from ce-1 cells (a human mammary epithelial cell line overexpressing c-ErbB2) treated or untreated with the antibody 4D5, which inhibits c-ErbB2 phosphorylation. Clones covering the full cDNA sequence of 6.4 kilobases were isolated from a breast cancer cDNA library. Although expression of PLU-1 in ce-1 cells is regulated by signaling from c-ErbB2, the gene is expressed in all the breast cancer cell lines examined, in cells cultured from primary breast cancers, and in the invasive and in situ components of primary breast cancers. Translation of the open reading frame predicts a protein of 1544 amino acids, which contains three PHD/LAP motifs, a specific DNA-binding domain found in a Drosophila protein (dri) and novel domains showing extensive homology with other human and non human gene products. Transient transfection of cell lines with MYC-tagged PLU-1 showed the protein to be localized in the nucleus and associated with discrete foci. The presence of the dri motif and PHD/LAP fingers together with the clear nuclear localization and consistent expression in breast cancers, suggest a role for PLU-1 in regulating gene expression in breast cancers. (+info)
Induction of the Tat-binding protein 1 gene accompanies the disabling of oncogenic erbB receptor tyrosine kinases.
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Conversion of a malignant phenotype into a more normal one can be accomplished either by down-regulation of erbB family surface receptors or by creating inactive erbB heterodimers on the cell surface. In this report, we report the identification and cloning of differentially expressed genes from antibody-treated vs. untreated fibroblasts transformed by oncogenic p185(neu). We repeatedly isolated a 325-bp cDNA fragment that, as determined by Northern analysis, was expressed at higher levels in anti-p185(neu)-treated tumor cells but not in cells expressing internalization defective p185(neu) receptors. This cDNA fragment was identical in amino acid sequence to the recently cloned mouse Tat binding protein-1 (mTBP1), which has 98.4% homology to the HIV tat-binding protein-1 (TBP1). TBP1 mRNA levels were found to be elevated on inhibition of the oncogenic phenotype of transformed cells expressing erbB family receptors. TBP1 overexpression diminished cell proliferation, reduced the ability of the parental cells to form colonies in vitro, and almost completely inhibited transforming efficiency in athymic mice when stably expressed in human tumor cells containing erbB family receptors. Collectively, these results suggest that the attenuation of erbB receptor signaling seems to be associated with activation/induction or recovery of a functional tumor suppressor-like gene, TBP1. Disabling erbB tyrosine kinases by antibodies or by trans-inhibition represents an initial step in triggering a TBP1 pathway. (+info)