Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A total of 396 adenocarcinomas of the stomach were examined immunohistochemically using antibodies specific for the internal domain of human c-erbB-2 protein. Forty of these (consisting of 35 well-differentiated and 5 undifferentiated types) overexpressed c-erbB-2, as evidenced by cytoplasmic membrane staining; these tumors were further examined by fluorescence in situ hybridization using a cosmid probe for 17q11.2-12 (c-erbB-2 locus) on formalin-fixed, paraffin-embedded tissues. This technique enabled us not only to detect c-erbB-2 amplification on a cell-by-cell basis, but also to compare the gene amplification with the protein expression, observe topographical distribution, and establish quantitative pictures of the amplification in vivo condition. In all 40 tumors, we observed gene amplification and found that the cancer cell with the amplification corresponded to the cells overexpressing c-erbB-2. In eight mucosal carcinomas, signals were coalesced to one or two clusters, indicating that the amplified gene resided in a homogeneous staining region (HSR). Among 32 carcinomas invading beyond muscularis mucosae, approximately half were mostly composed of cells with the amplification; the others had populations of tumor cells with and without amplification, which were sometimes in separate zones or areas and sometimes mixed together. In 22 cancers, the amplified genes were exclusively in HSR; however, cancer cells with multiple scattered signals-suggesting that the amplified genes were translocated to other chromosomes-were found exclusively in 6 tumors and concurrently with HSR in 4 tumors. These findings suggest that: (a) the amplification produces c-erbB-2 in the HSR form generally early in the carcinogenesis of gastric adenocarcinomas; and (b) in the process of cancer development, the amplified gene is lost in some cancer cells by uneven segregation of HSR in mitosis, whereas in others, it is kept in HSR or translocated to other chromosomal positions, thereby preserving overexpression of c-erbB-2 protein.
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PMID:Amplification of c-erbB-2 in gastric cancer: detection in formalin-fixed, paraffin-embedded tissue by fluorescence in situ hybridization. 952 Sep 47

Although the mechanism remains obscure, two histological subtypes of gastric carcinoma (GC), the diffuse and intestinal types, differ drastically in epidemiological, clinical, pathological and biological characteristics. We investigated whether the genetic alterations of several oncogenes and tumour suppressor genes could be correlated with the two histological subtypes. In 60 patients with GC, the overexpression of mutant p53 and c-erbB-2 oncoproteins was studied using immunohistochemical stains. Mutations of the p15 and p16 tumour suppressor genes were assessed by polymerase chain reaction, Southern blotting, and direct DNA sequencing. Overexpression of c-erbB-2 and p53 was found in 21 (35.0%) and 27 (45.0%) patients, respectively. Overexpression of the c-erbB-2 oncoprotein was more common in the intestinal type (15/32, 46.9%) and the advanced stage (19/45, 42.2%) than in the diffuse type (6/28, 21.4%) and the early stage (2/15, 13.3%) of GC (P<0.05). Similarly, p53 overexpression was more frequently found in the intestinal type (19/32, 59.4%) and the advanced stage (24/45, 53.3%) than in the diffuse type (8/28, 28.6%) and the early stage (3/15, 20.0%) of GC (P<0.05). Homozygous deletions of p16 in exon 1 were found in six (10.0%) patients. Five of them had the intestinal-type advanced GC. Neither point mutations of p16 nor alterations of p15 were detected. The frequency of alterations of p53, c-erbB-2, and p16 was not related to sex and Helicobacter pylori infection. No correlation of genetic changes between any two genes was observed. Our preliminary results indicate alterations in the p15 gene were not important in gastric tumorigenesis, while infrequent homozygous deletions in the p16 gene play a limited role in tumour progression of intestinal-type GC. Moreover, overexpression of c-erbB-2 and p53 is frequently encountered in the intestinal-type advanced GC. Alterations of p53, c-erbB-2 and p16 genes may function independently of each other in gastric carcinogenesis. The association between genetic alterations and histological subtypes supports the notion that a distinct pathogenesis may exist in different histological subtypes.
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PMID:Overexpression of mutant p53 and c-erbB-2 proteins and mutations of the p15 and p16 genes in human gastric carcinoma: with respect to histological subtypes and stages. 957 Feb 45

Although oncogenes are involved in tumor development and progression, their activation during human ontogenesis is inseparably associated with normal fetal development. The c-erbB-2-encoded oncoprotein p185 (HER-2/neu) is overexpressed on fetal epithelial cells, in the placenta, and in several human carcinomas. In patients with p185-overexpressing tumors and in pregnant women at term, increased serum levels of a 105 kDa proteolytic breakdown product corresponding to the extracellular domain of oncoprotein p185 are detectable. Estrogens have been described to be potent inhibitors of p185 expression in human breast cancer cells and to influence also p105 serum levels in females. Regarding the significantly poorer prognosis of patients with c-erbB-2-positive tumors, we discuss common features and differences between c-erbB-2 oncoprotein overexpression in pregnancy and in carcinogenesis.
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PMID:Expression of the c-erbB-2-encoded oncoprotein p185 (HER-2/neu) in pregnancy as a model for oncogene-induced carcinogenesis. 968 12

The expression and coexpression of EGFR, c-erbB-2 and c-erbB-3 in 21 gastric cancers and 20 chronic gastritis was examined using immunohistochemistry on fresh frozen tissues considering clinicopathological variables. Generally, gastric cancer patients showed a higher incidence of EGFR, c-erbB-2 and d-erbB-3 overexpression than the group with chronic gastritis (81% and 43%; 38% and 45%; 35% and 20%, respectively), however, statistically significant differences were found only for EGFR expression (p = 0.01). No association between immunoreactivity of all growth factor receptors and the histopathological structure of gastric cancer was observed. EGFR and c-erbB-3 proteins were detected more frequently in patients with III/IV than in I/II of TNM stages, while c-erbB-2 overexpression was higher in I/II vs. III/IV stages. In chronic gastritis with intestinal metaplasia and or coexisting carcinoma lesions, a higher frequency of the expression of studied proteins was observed in comparison with chronic gastritis without those alternations; however, these differences were statistically insignificant. The percentage of positive cases with coexpression of two proteins was comparable in gastric cancer and chronic gastritis (33% and 35%) but the simultaneous expression of all three receptors was evident only in gastric cancer (19%). Our results indicate that at least one or two members of EGFR related receptors could appear in the early stages of gastric tumorigenesis. The enhancement of c-erbB-2 and c-erbB-3 reactivity seems to cooperate with EGFR activation in the gastric cancer development. Our results indicate the promotional rather than direct transformational role for EGFR supergene family in gastric carcinogenesis.
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PMID:Expression of epidermal growth factor receptor family proteins (EGFR, c-erbB-2 and c-erbB-3) in gastric cancer and chronic gastritis. 970 36

The remnant stomach after partial gastrectomy is considered to have a predilection for the development of primary gastric carcinoma. However, early gastric stump carcinomas are uncommon because the diagnosis of gastric stump carcinoma is more difficult than that of carcinoma in the intact stomach. Triple early gastric stump carcinomas, as in the present case, are exceedingly rare and may provide some clues for further investigation of carcinogenesis in the gastric stump. We studied about the histological appearance, genetic alterations (P-53 gene, c-erbB-2 gene and K-ras gene), and expression of tumor-associated antigens (carcinoembryonic antigen, carbohydrate antigen 19-9, and sialyl-Tn) in this rare case. The three carcinomas differed from each other histologically. With respect to genetic alterations, c-erbB-2 was amplified in one lesion, but no mutations of K-ras and P-53 gene were detected. The three carcinomas also differed from each other on the expression of tumor-associated antigens. In noncancerous mucosal epithelium at the anastomosis showing hyperplasia and cystic formation of glandular epithelial cells, no genetic alterations were detected, but sialyl-Tn and carbohydrate antigen 19-9 were expressed. These results suggest that there may be different processes of carcinogenesis of the three carcinomas even though they occurred under identical environmental conditions to those that have increased cancer risk.
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PMID:Multiple early gastric stump carcinomas after gastrectomy for peptic ulcer. 973 51

The E-cadherin-mediated cell adhesion system is now considered to be an "invasion suppressor system" in cancer cells. Dysfunction of the E-cadherin system due to mutations of the genes of E-cadherin and catenins has not been reported in colorectal cancer. Histologically, well-differentiated colorectal cancer cells are found to be scattered at the invasive front in primary lesions and form glands again in metastatic sites. We have reported the association and presence of signal transduction between c-erbB-2/epidermal growth factor receptor (EGF-R) and beta-catenin in human cancer cells. This temporal dysfunction of the E-cadherin system observed in colon cancers may be caused by tyrosine phosphorylation of beta-catenin through activated receptor-type tyrosine kinases. Overexpression of EGF-R and tyrosine phosphorylation of beta-catenin are often observed in "focal dedifferentiated cells" at the invasive front of colorectal cancers. In addition, beta-catenin expression is regulated by the APC tumor suppressor gene product. Thus the E-cadherin-catenin system may play important roles not only in invasion and metastasis but also in the carcinogenesis of colorectal cancer.
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PMID:[Dysfunction of E-cadherin-catenin system in invasion and metastasis of colorectal cancer]. 974 18

Conventional histopathological criteria based on light microscopy are used in pulmonary oncologic pathology in order to establish the diagnosis of tumor, but most frequently they are insufficient, accurate diagnosis requiring ultrastructural and immunohistochemical investigations. The method of immunostaining allowed some molecular marker to be evaluated. Some of them seem to be important in carcinogenesis as a general process, while others have high specificity for lung tumors. Estimation of EGFR and c-erbB-2 protein immunoreactivity showed a significantly stronger staining with NSCLC and was correlated to the poor differentiation of the tumors, undergoing an aggressive biological behavior and an unfavorable prognosis. The expression of p53 protein was found in 19 cases by immunostaining with DO-7 antibody. Immunotracing of more than 50% of the tumoral cells was a predictive factor for the progression of the disease. The growing rate of tumoral proliferative activity was evaluated by immunotracing technique (MIB-1), allowing the Ki-67 index of labeling to be calculated.
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PMID:Immunohistochemical markers in the morphological diagnosis of lung carcinoma. 974 20

The mammary gland seems to be the only organ that is not fully developed at birth. Estrogens stimulate breast tissue via estrogen receptors (ERs). In the mammary gland, ER-mediated mechanisms have been shown to regulate: various growth factors, such as TGF-alpha and TGF-beta; enzymes, such as cathepsin D and plasminogen-activator; proto-oncogenes, such as c-fos, c-myc and HER-2/neu; cyclines and other regulatory substances that provide signaling systems for cell division and differentiation; other steroid receptors and epidermal growth factor receptors. Estrogen target genes contain estrogen-responsive elements. In these genes, transcription will be activated through interaction with the estrogen/ER protein complex. Subsequent activation of proto-oncogenes provides an explanation for the stimulating effect of estrogens on the glandular breast. Progesterone may be the key in influencing the risk of breast cancer with the peak of mitotic activity in the breast during the luteal phase of the menstrual cycle. On the other hand, in human breast cancer cell lines, both proliferation and inhibition have been observed with various progestational agents. Relevant biological and clinical issues are pregnancy and exposure to exogenous hormones. The intense hormonal stimulation of pregnancy (both estrogen and progesterone) has no adverse impact on the course of breast cancer. Pregnancy, with its mammogenetic differentiation, results in the protection of this organ from carcinogenesis. Characterization of specific lobular morphology serves as an indicator of the level of differentiation achieved by the organ, and thus provides means to assess the risk of the gland undergoing neoplastic transformation when exposed to given agents. Sufficient evidence exists to indicate the possibility of a slightly increased risk of breast cancer after approximately one decade of postmenopausal estrogen use. A review of the epidemiologic studies of postmenopausal hormone replacement and the risk of breast cancer fails to provide definitive evidence. Recent information derives from observations of cellular proliferation, plasma and tissue estradiol and progesterone receptor levels, and the percentage of apoptotic epithelial cells in human breast tissue. Several studies suggest that short-term, continuous combined HRT does not increase breast cancer recurrence or mortality. The participation of sexual hormones in the mammogenetic process during pregnancy might serve as an intermediate end point in assessing the effectiveness of hormones as chemopreventive agents. Investigations based on history, and breast morphology, should enable us to select estrogens and progestogens for HRT, and adopt optimal therapeutic regimens.
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PMID:Potential benefits of estrogens and progestogens on breast cancer. 992 May 36

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) has been used to rapidly profile the protein content of human cell lysates from MCF-10 cell and variant lines. The method was used to study the protein profiles of these cells as they progressed from normal breast epithelium to fully malignant cells. Distinct differences in the protein profiles were observed with progression, and specific proteins associated with carcinogenesis (p53, c-myc, and c-erbB-2) were heavily expressed in these cells as detected by MALDI-TOFMS. These proteins were also isolated using non-porous reversed-phase high performance liquid chromatography (NP-RP-HPLC) and mass analyzed by MALDI-TOFMS to provide molecular weight information without interference from other proteins in the whole cell lysates, and to avoid suppression effects in mixtures of proteins detected by MALDI-TOFMS. In order to confirm the identity of these oncoproteins, the cell lysates were subjected to one-dimensional (1-D) gel separation and subsequently electroblotted onto a poly(vinylidene difluoride) (PVDF) membrane for further analysis. Trypsin and cyanogen bromide digestions were performed on these proteins eluted from excised PVDF bands which were then analyzed by MALDI-TOFMS. The identity of these proteins was confirmed by database matching procedures.
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PMID:Protein profiles and identification of high performance liquid chromatography isolated proteins of cancer cell lines using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. 1003 81

Cyclin D1 protein plays an important part in regulating the progress of the cell during the G1 phase of the cell cycle. The cyclin D1 gene, CCND1, is amplified in approximately 20% of mammary carcinomas, and the protein is over-expressed in approximately 50% of cases. This has led to intensive study to ascertain whether cyclin D1 is a biological marker in breast cancer; however, the clinical work has produced unexpected results. Work in cell lines and in transgenic mice indicate that CCND1 is a weak oncogene and it was expected that, like c-erbB-2, over-expression of cyclin D1 protein would be associated with a poor prognosis. Early immunohistochemical prognostic studies produced equivocal results but we, and others, have recently shown that strong staining for cyclin D1 is more likely to be seen in well differentiated, estrogen receptor positive carcinomas. Furthermore, we have found that over-expression of cyclin D1 is actually associated with a good outcome, both in terms of prognosis and response to endocrine treatment. Cyclin D1 is frequently over-expressed in ductal carcinoma in situ but not in benign breast disease, including atypical ductal hyperplasia; hence its expression appears to be closely linked with carcinogenesis. In order to help explain the apparent beneficial effects of cyclin D1 over-expression, a number of closely associated cell cycle proteins have also been evaluated, including the cyclin dependent kinase inhibitor p27, which blocks the activating effects of cyclin D1. Initial reports show that high levels of p27 are associated with a good prognosis and we have shown a positive association between p27 and cyclin D1 expression. These clinical results of cyclin D1 are an example of how information obtained from basic cell biology studies needs to be complemented by clinical studies to ascertain the true worth of a prognostic marker.
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PMID:Cyclin D1 in breast cancer. 1006 68


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