Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0476089 (endometrial cancer)
 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The retinoblastoma-related gene Rb2/p130 encodes a protein that is a negative cell-cycle regulator normally expressed in a number of adult tissues. This protein shares many structural and functional features with the product of the retinoblastoma gene, one of the best-studied tumor-suppressor genes, and plays a fundamental role in growth control. The Rb2/p130 gene product associates with specific members of the E2F family and various cyclins, displaying a growth-suppressive activity specific for the G(0)/G(1) phases. It has been reported that Rb2/p130 is involved in the pathogenesis and progression of lung cancer and mesothelioma. We previously demonstrated for the first time that reduced immunohistochemical expression of Rb2/p130 was a strong independent predictor of poor outcome in endometrial cancer. The aim of the present study was to evaluate Rb2/p130 expression in normal, hyperplastic, and neoplastic endometrial lesions to determine whether the protein plays a significant role in endometrial carcinogenesis. We evaluated Rb2/p130 expression by immunohistochemistry staining in 102 specimens chosen to represent a spectrum of endometrial changes, including proliferative endometrium (n = 18), secretory endometrium (n = 18), simple or complex hyperplasia without atypia (n = 18), atypical hyperplasia (n = 18), and invasive carcinoma (n = 30). We found that Rb2/p130 was highly expressed in proliferative endometrium and in hyperplasia without atypia, the mean percentage of stained nuclei being 66% and 60%, respectively, but was downregulated in secretory endometrium, atypical hyperplasia, and carcinoma, with mean scores of 38%, 25%, and 22%, respectively. When categorized on a semiquantitative scale (negative v 1% to 50% v >50% positivity), endometrial cancer displayed significantly less staining than all other endometrial samples (P <.001). Poorly differentiated carcinomas (n = 9) showed a significantly lower immunoreactivity for Rb2/p130 than did well-differentiated carcinomas (n = 11; P =.005) and moderately differentiated carcinomas (n = 10; P =.03). In addition, atypical hyperplasia showed a significantly lower immunoreactivity than either proliferative endometrium (P =.003) or hyperplasia without atypia (P = 0.02). Our findings of a progressive decrease in Rb2/p130 expression from hyperplastic endometrium through atypical hyperplasia to poorly differentiated carcinomas suggest the involvement of this negative cell-cycle regulator in endometrial carcinogenesis. Furthermore, immunostaining for Rb2/p130 may prove diagnostically useful in the often difficult distinction between hyperplastic and atypical hyperplastic endometrium. HUM PATHOL 32:360-367.
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PMID:Expression of the retinoblastoma-related gene Rb2/p130 is downregulated in atypical endometrial hyperplasia and adenocarcinoma. 1133 52

Rb2/p130 is a member of the retinoblastoma family of proteins, consisting of Rb, Rb2 and p107, which are important negative regulators of cell cycle progression and differentiation. While Rb2 downregulation was observed in several malignant tumours including endometrial cancer, the role of p130 in breast carcinomas is still unknown. We investigated Rb2 protein expression in tumour tissue from 68 mammary and 41 endometrial carcinomas, 4 mammary cell lines, and normal tissue samples. Therefore, we performed Western blot experiments for Rb2, Rb, and the oestrogen and progesterone receptors (ER, PR-A, PR-B). Weak or absent Rb2 expression was more often found in endometrial (59%) than in mammary carcinomas (24%). We found significant positive correlations of Rb2 expression with Rb, ER, and PR-B in breast cancer samples, and of Rb2 with Rb, PR-A, PR-B, and younger age in endometrial carcinomas. No significant associations with histological grading, stage, nodal involvement, or Ki67 staining were detected. Rb2 mRNA expression was studied by semi-quantitative RT-PCR in 56 endometrial or mammary tissue samples and correlated significantly with Western blot results. Our results indicate that loss of Rb2 expression, mostly by transcriptional down-regulation, may be associated with the development and dedifferentiation of most endometrial and a subset of mammary carcinomas.
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PMID:Expression of Rb2/p130 in breast and endometrial cancer: correlations with hormone receptor status. 1150 94

The retinoblastoma family consists of the tumor suppressor nuclear phosphoprotein pRb/p105 and related proteins p107 and pRb2/p130. Recent immunohistochemical studies of the retinoblastoma family of proteins in lung and endometrial cancer and choroidal melanomas show a tight inverse correlation between the histologic grading in the most aggressive tumor types and pRb2/p130 expression. This led us to investigate the role of pRb2/p130 in salivary tumors. We studied the expression of pRb2/p130, p107, E2F4, p27, and PcNA by immunohistochemistry in a panel of 44 salivary gland tumors. We found a direct correlation between the cytoplasmic expression of pRb2/p130 and tumor grading and the presence of metastasis that was highly statistically significant (P < 0.001). Additionally, increased cytoplasmic pRb2/p130 expression was significantly correlated with a decreased probability of survival (P < 0.001). Interestingly, p107 nuclear expression showed a strong direct correlation when compared with the same variables. pRb2/p130 showed the highest percentage of undetectable nuclear levels in the specimens examined and the tightest inverse correlation (P < 0.0001) with both the histologic grading and pCNA expression in malignant salivary tumors. Additionally, E2F4 showed an identical localization pattern as to that of pRb2/p130. These data suggests an important role for pRb2/p130 in the pathogenesis and progression of certain salivary gland cancers.
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PMID:Expression of cell cycle-regulated proteins pRB2/p130, p107, E2F4, p27, and pCNA in salivary gland tumors: prognostic and diagnostic implications. 1586 22