Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The bcl-2 family of proteins includes some important regulators of apoptosis. Among these, bcl-2 and bcl-xL prevent cells from entering apoptosis, whereas bax and bcl-xS can induce cell death. Alterations in the control of this process can lead to a decrease in cell death, thus contributing to neoplastic growth. Diminished susceptibility to chemotherapy has also been attributed, in in vitro systems, to alterations in the levels of bcl-2, bax, or bcl-x. We analyzed the expression of bcl-2, bax, bcl-xL, and bcl-xS in normal and neoplastic ovarian tissues by reverse transcriptase-PCR and Western blotting. The RNA and protein levels were significantly correlated for all genes. Interestingly, the levels of these genes in normal and neoplastic tissues were significantly different: bcl-2 was higher in normal tissue (P < 0.002), whereas bax and bcl-xL were higher in carcinoma (P < 0.018 and P < 0.030, respectively). bcl-xS was present at low levels in 83% of neoplastic samples and was undetectable in normal tissue. Reverse transcriptase-PCR analysis of 74 tumors showed no major correlation with clinicopathological parameters or with response to chemotherapy. Only bax and bcl-xL were correlated with progesterone receptor levels (n = 29, r = +0.44, P < 0.0189, and r = -0.40, P < 0.035, respectively). No correlation was found with estrogen receptor levels or with p53 immunostaining. Our data indicate that the regulation of the bcl-2 family of proteins differs between normal and neoplastic ovarian tissues. Moreover, the modulation of these genes in ovarian carcinoma is different compared to other tissues; therefore, tissue specificity is very important in regulation of the bcl-2 family of proteins.
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PMID:bcl-2, bax, bcl-XL, and bcl-XS expression in normal and neoplastic ovarian tissues. 951 44

To evaluate the clinical significance of drug resistance mechanisms in breast cancer, we examined the expression of MDR1 and MRP in primary breast carcinoma and normal adjacent tissue using a highly quantitative and reproducible reverse transcription-PCR assay. Expression of both genes was observed in all specimens examined, both tumor (n = 74) and normal adjacent tissue (n = 55). The expression of MDR1, however, was low, with the level of expression being 25 times less than the drug-resistant control cell line KB 8-5. Immunohistochemical analysis of P-glycoprotein corroborated the PCR results; only 6% (2 of 31) were positive for JSB1 staining, and 0 of 32 were positive for for UIC2. MRP expression did not exceed control cell line levels, and immunohistochemistry detected moderate levels of expression. MDR1 expression was independent of grade, stage, tumor size, nodal status, metastasis, and estrogen receptor and progesterone receptor status. There was, however, a significant correlation of MDR1 expression with age and histology. Approximately twice the expression of MDR1 was observed in the < 50 age group compared to the > 50 age group, and lobular carcinoma had 4 times the expression of MDR1 of other histological types. MRP expression was independent of all other clinical parameters. Thus, these results show that although MDR1 expression is detectable in primary breast carcinoma by PCR, this expression as measured by quantitative reverse transcriptase-PCR is extremely low. The significance of these low levels is yet to be determined. MDR1 expression was higher in < 50 age group and lobular carcinoma, which may contribute to poor prognosis associated with young age and lobular histology.
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PMID:Quantitative reverse transcriptase-polymerase chain reaction measured expression of MDR1 and MRP in primary breast carcinoma. 962 74

The identification of menstrual blood stains can be improved by detection of messenger ribonucleic acid (mRNA) specific for epithelial (endometrial) cells. RNA molecules, however, are believed to be unstable and require careful sample processing. In this study, we have investigated the extraction of RNA suitable for reverse transcriptase-polymerase chain reaction (RT-PCR) from dried blood stains stored for up to six months. With a modified RNA isolation protocol, it was possible to obtain RNA from dried blood stains with at least 5 x 10(2) leukocytes. In an additional experiment, we evaluated the RNA isolation from mixed stains composed of leukocytes and T47D cells, a breast cancer-derived cell line with epithelial origin. Detection of 10(2) T47D cells in a total number of 10(5) leukocytes was possible by amplification of cytokeratin 19 mRNA and progesterone receptor-mRNA specific for hormonally regulated epithelial cells. In both experiments amplification results were not dependent on storage time with similar data from one day to six months. Furthermore, it was possible to identify dried menstrual blood samples by showing the presence of mRNA specific for epithelial cells. These results demonstrate for the first time, that RNA suitable for RT-PCR, can be isolated from forensic specimens stored up to at least six months, and that a small number of epithelial (endometrial) cells can be identified in dried blood specimens. Using this method, it will be possible to identify the origin of small and partially degraded blood samples which can be especially useful in forensic evaluation of cases with sexual offense.
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PMID:Detection of epithelial cells in dried blood stains by reverse transcriptase-polymerase chain reaction. 1058 61

Alteration of psoriasin (S100A7) expression has previously been identified in association with the transition from preinvasive to invasive breast cancer. In this study we have examined persistence of psoriasin mRNA and protein expression in relation to prognostic factors in a cohort of 57 invasive breast tumors, comprising 34 invasive ductal carcinomas and 23 other invasive tumor types (lobular, mucinous, medullary, tubular). We first developed an IgY polyclonal chicken antibody and confirmed specificity for psoriasin by Western blot in transfected cells and tumors. The protein was localized by immunohistochemistry predominantly to epithelial cells, with both nuclear and cytoplasmic staining, as well as occasional stromal cells in psoriatic skin and breast tumors; however, in situ hybridization showed that psoriasin mRNA expression was restricted to epithelial cells. In breast tumors, higher levels of psoriasin measured by reverse transcriptase-polymerase chain reaction and Western blot (93% concordance) were significantly associated with estrogen and progesterone receptor-negative status (P < 0.0001, P = 0.0003), and with nodal metastasis in invasive ductal tumors (P = 0. 035), but not with tumor type or grade. Psoriasin expression also correlated with inflammatory infiltrates (all tumors excluding medullary, P = 0.0022). These results suggest that psoriasin may be a marker of aggressive behavior in invasive tumors and are consistent with a function as a chemotactic factor.
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PMID:Psoriasin (S100A7) expression and invasive breast cancer. 1059 35

beta(1C) integrin is an unspliced form of the integrin beta(1) subfamily, which has been shown to inhibit cell proliferation in vitro. Using an affinity-purified rabbit antibody, we have investigated 283 previously untreated breast carcinomas, with the aim of ascertaining the actual prevalence of beta(1C) expression in these tumors and of defining its pathological correlates. Immunoblotting and reverse transcriptase-polymerase chain reaction experiments have also been performed in selected cases, to confirm the immunocytochemical findings. Overall, beta(1C) immunoreactivity was down-regulated (ie, expressed in < 50% of the neoplastic cells) in 114 cases (40.3%). Down-regulation of beta(1C) expression in breast carcinomas correlated significantly with the tumor grade, the proliferative fraction (as evaluated by Ki-67 immunostaining with the MIB-1 monoclonal antibody), the estrogen and progesterone receptor status, and the tumor size (pT classification) and marginally with the node status. In a multivariate analysis with all available measures fitted simultaneously, tumor grade (P = 0.004), Ki-67 immunolabeling (P = 0.01), and pT categories (P = 0.04) were significantly associated with beta(1C) immunoreactivity. Although the short follow-up time (2-3 years) of the current series of patients does not allow the performance of survival analyses, the correlation of beta(1C) expression with tumor size, grade, and proliferative fraction and its alleged role as an upstream regulator of p27(kip1) make this integrin variant a likely novel prognostic parameter for invasive carcinomas of the breast.
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PMID:Down-regulation of beta(1C) integrin in breast carcinomas correlates with high proliferative fraction, high histological grade, and larger size. 1062 64

The pathophysiological role for the expression of human chorionic gonadotrophin (hCG) in malignant neoplasms is currently speculative. We investigated the overall expression of genes hCG-beta 5, 3, 8 and 7 in breast carcinoma (n=214), fibroadenoma (n=37) and macromastia (n=10) by quantitative reverse transcriptase-PCR. Eighty (37.4%) of the breast cancer samples revealed positive hCG-beta mRNA expression and the mean value was 67. 9 copies per 200 ng total RNA (range: 0-1743; 95% confidence interval (CI) for mean: 44-92). Fibroadenomas had more frequently detected (56.8%) and greater hCG-beta copy numbers (mean 86.9; range: 0-845; 95% CI for mean: 35-138). Macromastia probes yielded no positive hCG-beta mRNA. The hCG-beta mRNA expression was significantly different in the three histological subgroups (P=0. 006). Among breast carcinomas, a positive correlation was detected between hCG-beta mRNA copy numbers and progesterone receptor (PgR) values (P<0.001). No significant differences were seen regarding disease-free (P=0.87) and overall survival (P=0.20) depending on hCG-beta mRNA status. Finally, our findings do not support a role for hCG-beta in malignant transformation of human breast cells and indicate a possible involvement of hCG-beta in benign breast disease. The relationship with PgR expression may suggest that progestins regulate the expression of hCG in breast epithelial cells.
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PMID:Human chorionic gonadotrophin-beta transcripts correlate with progesterone receptor values in breast carcinomas. 1065 95

Nuclear and cytoplasmic proteins of human female breast cancer were analysed by one-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Oestrogen receptor and progesterone receptor expression was determined by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method. The electropherograms were developed by silver nitrate staining and quantitative analysis was carried out by video densitometer using the software Gel-Pro Analyzer. Nuclear and cytoplasmic proteins of breast carcinomas and normal tissue differed both qualitatively and quantitatively. Nuclear polypeptides of 108, 53 and 48 kD as well as the 36 kD cytoplasmic polypeptide were specific for tumour samples, while the 51 kD nuclear polypeptide was detected only in normal tissue. Quantitative differences in band density were noted in the 32 kD nuclear polypeptide. This polypeptide was expressed in greatest concentration in infiltrating ductal carcinomas which also indicated the greatest oestrogen receptor gene expression. This relationship appeared to be statistically significant (p < 0.005). No correlations were evident between the 32 kD protein expression and the progesterone receptor gene expression in any of the tissue types examined, nor between the 32 kD protein and the patient's age or tumour grade.
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PMID:Female breast carcinomas: nuclear and cytoplasmic proteins versus steroid receptors. 1075 81

The present study, to our knowledge, is the first to demonstrate presence of progesterone receptor (PR) transcript in human spermatozoa. The study shows the presence of low copy number PR mRNA in mature human spermatozoa. The PR transcript in spermatozoa was detected by reverse transcriptase-polymerase chain reaction using primers specific for the hormone binding domain and the DNA binding domain of the conventional uterine PR. Further, the cDNA sequence of the partial PR transcript from spermatozoa was found to be identical to the region spanning nucleotides 2694 to 3230 of the conventional PR full-length cDNA sequence. This study also indirectly suggests that the PR protein indeed is an intrinsic sperm protein and is not acquired through proteinaceous secretions of accessory reproductive organs.
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PMID:Detection of progesterone receptor transcript in human spermatozoa. 1081 62

Effects of age on uterine histoarchitecture, cell proliferation, and hormone receptor expression were determined for neonatal ewe lambs from birth (Postnatal Day [PND] 0) to PND 56. Uteri were histologically evaluated and proliferating cell nuclear antigen (PCNA), estrogen receptor alpha (ER-alpha), progesterone receptor (PR), and prolactin receptor (PRL-R) expression were characterized by in situ hybridization (ISH), immunohistochemistry, or both. The most striking feature of neonatal uterine development was the genesis and development of glands in the intercaruncular areas of endometrium. After birth, endometrial glandular epithelium (GE) budded and differentiated into the underlying stroma from the luminal epithelium (LE) between PNDs 1 and 7. Between PNDs 14 and 56, extensive coiling and branching morphogenesis of nascent endometrial glands occurred. By PND 56, the uterine wall appeared to be histoarchitecturally mature. At birth, nuclear PCNA protein was strongly detected in LE. Between PNDs 7 and 56, high levels of PCNA, ER-alpha, and PR gene expression were detected in both nascent and developing GE. Higher levels of PCNA and ER-alpha expression were detected in GE at the tips of developing glands as well as in the surrounding stroma. Progesterone was below detectable limits in serum. Serum estradiol-17beta levels were high on PND 1, increased from PNDs 14 to 28, and declined from PND 42 to PND 56. Serum PRL levels increased from PNDs 1 to 14 and declined thereafter. Using ISH and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis, expression of mRNAs for short and long forms of the ovine PRL-R were first detected in nascent GE on PND 7 and increased between PNDs 7 and 56 in proliferating and differentiating GE. These results indicate that 1) uterine gland genesis is initiated between PNDs 1 and 7 after birth and is essentially completed by PND 56; 2) neonatal uterine morphogenesis involves temporal and spatial alterations in cell proliferation and ER-alpha, PR, and PRL-R gene expression; 3) PRL-R expression is a unique marker of GE differentiation and proliferation; and 4) serum estradiol-17beta and PRL levels increase during the onset of GE tubular branching morphogenesis. Results support the hypothesis that neonatal ovine uterine development involves epithelial PRL-R and ER-alpha activation to stimulate and maintain endometrial gland genesis and branching morphogenesis.
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PMID:Neonatal ovine uterine development involves alterations in expression of receptors for estrogen, progesterone, and prolactin. 1099 45

Despite the various responses of human skin to female sex hormones, cellular and subcellular targets and the mechanisms of action of estrogen and progesterone in human skin are not well understood. The detection of estrogen receptor (ER) and progesterone receptor (PR) in the skin is of great importance to understand the effect of estrogen and progesterone. In primary cultures of human keratinocytes, expression of ER and PR was monitored by immunocytochemistry and reverse transcriptase polymerase chain reaction (RT-PCR). Paraffin embedded skin tissues were stained with monoclonal antibodies to human ER and PR by immunohistochemistry. Cultured human keratinocytes expressed cytoplasmic PR protein and PR mRNA transcripts. By contrast, ER was detected only at the mRNA level. Suprabasal keratinocytes from samples of pruritic urticarial papules, plaques of pregnancy (PUPPP) and psoriasis were stained positively only for PR, while those from samples of erythema nodosum were negative for both ER and PR. Lesional epidermis of PUPPP showed positive PR immunoreactivity, while nonlesional epidermis did not. No other cells in the normal human skin were stained with ER and PR. The present study suggests that by expressing PR human keratinocytes act as targets for progesterone action.
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PMID:Expression of progesterone receptor in human keratinocytes. 1119 91


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