Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reverse transcriptase polymerase chain reaction (RT-PCR) using primers for the recently cloned human CGRP1 receptor detected mRNA expression of CGRP1 receptors in trigeminal ganglia and cerebral vessels, obtained at autopsy or during neurosurgical tumor resections. An RT-PCR product of the expected size (339 bp) was seen in cerebral arteries, both in the presence and in the absence of endothelium and in trigeminal ganglia. Sequence analysis of the RT-PCR product of the published sequence showed 100% homology with the human CGRP1 receptor. The presence of the CGRP1 receptor mRNA in human trigeminal ganglia and cerebral blood vessels, indicates the occurrence of both prejunctional (trigeminal) and postjunctional location (blood vessels) of the CGRP1 receptor.
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PMID:Expression of calcitonin gene-related peptide1 receptor mRNA in human trigeminal ganglia and cerebral arteries. 923 95

The Wilms'-tumor gene WT1 may have a different function from a tumor-suppressor gene in some leukemias. Using the 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat leukemia system, we examined whether WT1 expression was involved during leukemogenesis, since this model enabled us to analyze cells altered by DMBA at various stages of leukemogenesis. By the semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) method, WT1 expression was detected in 15 (71%) of 21 DMBA-induced erythroblastic leukemias. Among 15 WT1-expressing leukemias, GATA-1, which is an erythroid-specific transcription factor and might regulate WT1 expression, was also expressed in 13 cases (p < 0.05). On the other hand, WT1 expression was not detected in any normal or early pre-leukemic rats and was detected in 1 of 8 rats in late pre-leukemic stages. These results showed that cells with a high expression level of WT1 tended to develop into leukemia and that WT1 contributed to leukemogenesis in the late stage, suggesting that the expression of WT1 plays an important role in cell proliferation and in maintaining the viability of some leukemia cells.
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PMID:WT1 contributes to leukemogenesis: expression patterns in 7,12-dimethylbenz[a]anthracene (DMBA)-induced leukemia. 925 12

GnRH receptors belong to the family of G protein-coupled receptor proteins and have been localized to the anterior pituitary, brain and reproductive organs as well as many steroid-dependent tumor tissues. Recently, cDNAs for the GnRH receptors of several species including the human have been cloned. To determine the structure of the gene encoding the human GnRH receptor, we isolated the receptor gene clones from the human genomic libraries. Comparison of the genomic and cDNA sequences revealed that the human GnRH receptor gene is composed of three exons and two introns and spans over 20 kb in size. Exon 1 encodes the 5' untranslated sequence and nucleotide +1 to +522 in the open reading frame, exon 2 encodes nucleotide +523 to +742 and exon 3 encodes nucleotide +743 to +987 in the open reading frame as well as the 3' untranslated sequence. Southern blot analysis of genomic DNA and localization of the GnRH receptor gene to a single site on human chromosome 4 (4q13) indicate the presence of a single copy of the gene in the human genome. Several regulatory sequences for various hormones and other regulatory factors were identified, including PEA-3, AP-1, AP-2, and Pit-1 sites. In addition, glucocorticoid/progesterone response element thyroid hormone response element, and cAMP response element sequences were identified. Reverse transcriptase-primer extension and 5' RACE analysis of the human pituitary RNA demonstrated the presence of multiple transcriptional start sites upstream of the translational start site. Analysis of the 5' flanking region of the gene also revealed the presence of multiple TATA and CAAT sequences. The finding of multiple transcriptional start sites raises the possibility of tissue-specific regulation and the existence of variable size transcripts. Chimeras containing 1.26 kb (-534 to 728) of the 5' flanking region of the receptor gene and the luciferase (Luc) gene expressed a significant luciferase activity when transfected into a human endometrial tumor cell line (HEC-1A) and a breast tumor cell line (MCF-7) but not in a mouse pituitary gonadotrope cell line (alpha T3-1), suggesting the existence of multiple promoter elements in the gene. These findings indicate a multiplicity of regulation of expression of the GnRH receptor and provide the substrate for detailed investigation in the reproductive system.
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PMID:Molecular structure of the human gonadotropin-releasing hormone receptor gene. 1102 3

An alternatively spliced mRNA coding for a variant estrogen receptor (ER) missing exon 4 (ERdelta4) was detected in the breast tumor cell line MCF7 and meningioma tissue by using the reversed transcriptase PCR technique. The trans-activational properties of this mutant ER were assessed in embryo carcinoma P19EC and human choriocarcinoma JEG3 cells by co-transfection of the ERdelta4 expression vector with an oxytocin promoter construct containing an estrogen-responsive element. ERdelta4 did not trans-activate the oxytocin promoter in either a hormone-dependent or -independent manner. Co-transfection of ERdelta4 together with the wtER did not show any interference of ERdelta4 on the stimulation of the oxytocin promoter by the wtER. ERdelta4 was translated in vitro. Its capacity to bind estradiol, and the binding of the variant to a synthetic estrogen-responsive element were compared to those of the wild-type receptor. ERdelta4 did not bind to a synthetic estrogen-responsive element, nor did it bind estradiol. Hence, ERdelta4 appears to be a silent variant and we speculate that it is without any role in tumor progression.
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PMID:Functional analysis of an alternatively spliced estrogen receptor lacking exon 4 isolated from MCF-7 breast cancer cells and meningioma tissue. 939 58

One of the loci for neuroblastoma suppressor genes is chromosome 18q21 where the DPC4 tumor suppressor gene, as well as the DCC and MADR2 genes, is located. DPC4 is a molecule of the TGF-beta signal which regulates differentiation of the neural crest precursor cells from which neuroblastoma originates. During the search for the significance of DPC4 as a candidate neuroblastoma suppressor gene, we found that there are at least two variant forms of the DPC4 transcripts by using the reverse-transcriptase-PCR procedure. The subsequent sequencing analysis has revealed that one is missing exons 5 and 6 and the other is missing exons 4-6. Both splice variants were frequently observed in neuroblastomas and at low levels in normal tissues. Though the functional role of the DPC4 splice variants is unknown, they might be important in regulating the TGF-beta signaling not only in neuroblastomas but also in other tumors and normal tissues.
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PMID:DPC4 splice variants in neuroblastoma. 946 9

We have derived a cardiac muscle cell line, designated HL-1, from the AT-1 mouse atrial cardiomyocyte tumor lineage. HL-1 cells can be serially passaged, yet they maintain the ability to contract and retain differentiated cardiac morphological, biochemical, and electrophysiological properties. Ultrastructural characteristics typical of embryonic atrial cardiac muscle cells were found consistently in the cultured HL-1 cells. Reverse transcriptase-PCR-based analyses confirmed a pattern of gene expression similar to that of adult atrial myocytes, including expression of alpha-cardiac myosin heavy chain, alpha-cardiac actin, and connexin43. They also express the gene for atrial natriuretic factor. Immunohistochemical staining of the HL-1 cells indicated that the distribution of the cardiac-specific markers desmin, sarcomeric myosin, and atrial natriuretic factor was similar to that of cultured atrial cardiomyocytes. A delayed rectifier potassium current (IKr) was the most prominent outward current in HL-1 cells. The activating currents displayed inward rectification and deactivating current tails were voltage-dependent, saturated at >>+20 mV, and were highly sensitive to dofetilide (IC50 of 46.9 nM). Specific binding of [3H]dofetilide was saturable and fit a one-site binding isotherm with a Kd of 140 +/- 60 nM and a Bmax of 118 fmol per 10(5) cells. HL-1 cells represent a cardiac myocyte cell line that can be repeatedly passaged and yet maintain a cardiac-specific phenotype.
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PMID:HL-1 cells: a cardiac muscle cell line that contracts and retains phenotypic characteristics of the adult cardiomyocyte. 950 Dec 1

Reverse transcriptase polymerase chain reaction for the detection of tyrosinase-mRNA-positive cells in peripheral blood of melanoma patients, as a possible marker of hematogenous dissemination, has demonstrated varying detection rates. This study examined the sensitivity and reproducibility of the technique using a protocol of multiple polymerase chain reaction to determine circulating melanocytic cells. For each of the 123 melanoma patients included in this study, four nested polymerase chain reactions were performed from two blood specimens requiring both polymerase chain reactions from at least one blood sample to be positive to consider a patient as positive. Thus, a definitive result was obtained in 98% of the cases, whereas only 1.6% lacked conclusive findings. Thus, we found a correlation between the tyrosinase detection rate and the clinical stage. Circulating tyrosinase-mRNA-positive cells were detected in 13% of patients with primary tumor, 17% with regional skin/lymph node metastasis, and 44% with distant metastasis. Positivity also correlated with known melanoma progression markers such as gender, tumor thickness, and histologic type. Positive results were obtained more frequently in (i) men compared with women, (ii) patients with thick primary melanomas (> 4 mm: 38%) compared with those with thinner tumors (1.1-4 mm, 22%; < or = 1 mm, 5%), and (iii) patients with nonclassifiable (38%), nodular (34%), and occult primary melanomas (30%) compared with those with acrolentiginous (17%), superficial spreading (9%), or lentigo maligna melanoma (0%). These findings suggest that detection of tyrosinase-mRNA-positive cells in peripheral blood is not an adequate marker for identifying melanoma patients with distant metastasis. Reverse transcriptase polymerase chain positivity in early melanoma stages, however, as corresponding to other prognostic parameters, may indicate increased risk for the development of hematogenous metastasis and may be of value as a progression marker.
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PMID:RT-PCR for tyrosinase-mRNA-positive cells in peripheral blood: evaluation strategy and correlation with known prognostic markers in 123 melanoma patients. 950 46

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

A role for human papilloma virus (HPV) infection in the pathogenesis of head and neck neoplasms has gained support in recent years. Expression of two early-region HPV genes, E6 and E7, is widely accepted as essential for viral-induced carcinomas of the genital tract. These oncoproteins interact with the products of the cellular tumor suppressor genes, p53 and retinoblastoma, and inactivate them. Examining E6/E7 transforming gene expression is an important step toward elucidating the pathogenesis of HPV in head and neck neoplasms. We introduce nasal inverted papilloma (IP) as a novel system for evaluating viral genomic expression and transforming gene regulation of tumorigenesis by virtue of its association to HPV infection and potential for malignant progression. We describe here a reverse transcriptase-polymerase chain reaction approach for the detection of HPV E6/E7-specific transcripts in RNA extracted from IR. A primer pair flanking previously mapped HPV 6 E6/E7 splice donor/acceptor sites was used to direct amplification of cDNA. Reverse transcriptase-polymerase chain reaction experiments generated products representing the 1.2 Kb E1E4 splice transcript and a smaller unclassified fragment in IP from two patients. These results provide evidence for HPV 6 E6/E7 expression in IP with the potential to encode transforming proteins.
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PMID:The HPV 6 E6/E7 transforming genes are expressed in inverted papilloma. 952 9

We report the development of a reverse-transcriptase polymerase chain reaction assay that detects (in paraffin-embedded, formalin-fixed tissue) the SYT-SSXchimeric RNA transcript resulting from the t(X;18) of synovial sarcoma. The primers chosen detect both of the SSX1 and SSX2 partners, and the target sequence is small enough (87 base pairs) to be reliably detected in archival and variably processed consultation material. To demonstrate its usefulness, we applied it to 14 problematic cases, including spindle cell tumors of the thoracic region, of the neck, and of subcutaneous tissue. For instance, we show that, depending on the location, synovial sarcoma can mimic malignant solitary fibrous tumor, the spindle epithelial tumor with thymus-like differentiation, or skin adnexal tumors. Molecular detection of the SYT-SSX chimeric RNA should allow the reclassification of difficult cases in which the morphologic features overlap different entities or in which tumor nosology is still evolving.
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PMID:Detection of the SYT-SSX chimeric RNA of synovial sarcoma in paraffin-embedded tissue and its application in problematic cases. 955 26


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