Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Turcot syndrome (TS) is a rare, probably autosomal recessive, disorder characterized by development of primary neuroepithelial tumors of the central nervous system (CNS) and numerous adenomatous colorectal polyps. To examine the possible involvement of mutations of the APC gene, which is responsible for familial adenomatous polyposis (FAP), in Turcot syndrome, we examined DNAs from TS patients for alterations in this gene by means of ribonuclease protection analysis. Germ-line APC mutations were detected in each of three unrelated cases of TS, and additional (somatic) mutations were observed in colonic adenomas that had developed in one of these patients. However, no somatic mutations in APC were found among 91 neuroepithelial tumors (medulloblastoma, glioblastoma, astrocytoma, and oligodendroglioma), whether sporadic or associated with TS. These results suggest that the APC gene is associated with pathogenesis of one feature of TS, but that at least one other gene is responsible for the genesis of neuroepithelial tumors in the CNS.
Genes Chromosomes Cancer 1994 Mar
PMID:Germ-line and somatic mutations of the APC gene in patients with Turcot syndrome and analysis of APC mutations in brain tumors. 751 58

A number of reports associate human papillomavirus (HPV) with cervical cancer and cancer cell lines derived from this tumour type. Considerably fewer reports have focused on the role of HPV in carcinomas from other sites of female anogenital squamous epithelia. In this study we have tested for the presence of HPV in eight low-passage vulvar carcinoma cell lines and one extensively passaged cell line, A431. One cell line from a primary vaginal carcinoma was included. The presence of the HPV was evaluated by the polymerase chain reaction (PCR), by Southern blot analysis and by two-dimensional gel electrophoresis. General primer-mediated PCR was applied by using primers from the L1 region, E1 region and HPV 16 E7 region. Southern blot hybridisation was performed under low-stringency conditions (Tm = -35 degrees C) using a whole genomic HPV 6/16/18 probe mixture and under high stringency conditions (Tm = -18 degrees C) with the whole genomic probes of HPV 16 and 33. HPV 16 E6-E7 mRNA was assessed by ribonuclease protection assay (RPA). HPV was found in only one vulvar carcinoma cell line, UM-SCV-6. The identified type, HPV 16, was integrated in the cell genome and could be amplified with all primers used. Also E6-E7 transcripts were found in these cells. Five original tumour biopsies were available from the HPV-negative cell lines for in situ hybridisation. All these were HPV negative with both the HPV 6/16/18 screening probe mixture under low stringency and the HPV 16 probe under high stringency. The results indicate that vulvar carcinoma cell lines contain HPV less frequently than cervical carcinoma cell lines and suggest that a significant proportion of vulvar carcinomas may evolve by an HPV-independent mechanism.
Br J Cancer 1995 Jul
PMID:Human papillomavirus in vulvar and vaginal carcinoma cell lines. 759 42

The biological behavior of prostatic cancer is influenced by many host and tumor factors. The proliferative activity of the malignancies can be one of those parameters which serve as the basis to estimate prognosis and design treatment. Here, DNA content and S-phase fraction of prostatic cancer samples obtained by radical prostatectomy from 46 patients were related to other known tumor characteristics (PSA, staging, grading). Nuclei from the paraffin embedded materials were isolated with overnight trypsin-ribonuclease mixture digestion. DNA content and cell cycle distribution were determined by flow cytometry. A correlation was found between the PSA concentration, grading and staging on the one hand and S-phase fraction on the other. DNA content correlated with grading. No kinetic parameter correlated with the nodal involvement. Due to the association between abnormal DNA content plus SPF > 5% with advanced stage and less differentiated appearance of the tumor, we can conclude that these parameters are useful to estimate prognosis.
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PMID:DNA content of prostatic cancer measured by flow cytometry in patients undergoing radical prostatectomy. 764 37

P-glycoprotein (PGP), a transporter conferring multidrug resistance to cancer cells, is expressed in the kidney. C219 monoclonal antibody binding revealed PGP in proximal tubules and mesangium of mouse kidneys. A cell line (TKPTS) expressing PGP was developed from proximal tubules of the 8Tg(SV40E)Bri7 mouse. Northern blot analysis demonstrated a 5.0-kb message identified as mdr1 by ribonuclease protection assay. Cyclosporin A (CSA) at 0.15 and 10 microM increased cellular accumulation of verapamil (VRP) by 32 and 121%, respectively (P < 0.001). VRP at 5 microM increased steady-state cellular accumulation of CSA by 46% (P = 0.02). Basal-to-apical transport of the PGP substrate vinblastine was inhibited by VRP. Rhodamine-123 (R-123) influx was rapid and independent of PGP. R-123 efflux was inhibited by VRP and CSA. Inhibition of PGP transport by VRP, CSA, and PSC-833 decreased the 50% effective dose of adriamycin. The concomitant administration of VRP and CSA was not deleterious and coincided with preferential accumulation of VRP over CSA. Inhibition of PGP-mediated transport is demonstrated as a mechanism of renal cell toxicity.
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PMID:Expression and function of P-glycoprotein in a mouse kidney cell line. 765 14

Increased message levels of testosterone-repressed prostate message-2 (TRPM-2) have been associated with programmed cell death in many tissues. To study its involvement in the apoptotic elimination of hepatocytes during liver involution and regeneration, levels of TRPM-2 message were evaluated in situ and by the ribonuclease protection assay. Although significant increases in apoptotic bodies were observed in rats 96 h following treatment with lead nitrate and ethylene dibromide, an increase in TRPM-2 message was not detected. Therefore, the expression of TRPM-2 mRNA may be a poor indicator of the extent to which apoptosis occurs during liver involution.
Cancer Lett 1993 Jul 30
PMID:Expression of TRPM-2 during involution and regeneration of the rat liver. 768 26

Mitotic index is a clinically important parameter in cancer pathology. We developed a staining method using Toluidine Blue to detect efficiently and rapidly mitotic figures in sections of formalin-fixed paraffin-embedded human and rat tissues. Sections were stained at acid pH with a 0.01% Toluidine Blue solution after removal of RNA with hydrochloric acid or ribonuclease. The optimal pH of the TB staining solution was found to be 4.5 for rat tissues and 3.5 for human tissues. This procedure stained mitotic figures much more intensely than other (extra)cellular structures. A quantitative estimate of the total number of nuclei in the field where mitotic figures were counted, was obtained in an adjacent section hydrolysed in 5 N hydrochloric acid and stained by the Feulgen reaction with a Schiff-type reagent containing 0.01% Toluidine Blue. This method specifically stained interphase and mitotic nuclei and the field cellularity could be quantified by image cytometry. When these procedures were performed on two consecutive serial sections, a mitotic index could be determined accurately by relating the count of mitotic figures to the number of tumour cells.
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PMID:A rapid and simple staining method, using toluidine blue, for analysing mitotic figures in tissue sections. 769 82

We have found growth-promoting activity for vascular endothelial cells in the conditioned medium of a human lung cancer cell line, T3M-11. Purification and characterization of the growth-promoting activity have been carried out using ammonium sulfate precipitation and gel-exclusion chromatography. The activity migrated as a single peak just after ribonuclease. It did not bind to a heparin affinity column. These results suggest that the activity is not a heparin-binding growth factor (including fibroblast growth factors) or a vascular endothelial growth factor. To identify the molecule exhibiting the growth-promoting activity, a cDNA encoding the growth factor was isolated through functional expression cloning in COS-1 cells from a cDNA library prepared from T3M-11 cells. The nucleotide sequence encoded by the cDNA proved to be identical with that of insulin-like growth factor II.
Jpn J Cancer Res 1995 Feb
PMID:Isolation of a cDNA for a growth factor of vascular endothelial cells from human lung cancer cells: its identity with insulin-like growth factor II. 773 Jan 45

Wild-type as well as variant oestrogen receptor (ER) mRNAs with exon 5 and 7 deleted were identified in a panel of human breast tumour cell lines by reverse transcriptase-polymerase chain reaction followed by dideoxynucleotide sequence analysis, and then quantitated by ribonuclease protection analysis. All cell lines categorised as ER+ by ligand-binding analysis expressed both wild-type and variant ER transcripts. Most cell lines classified as ER- did not express any ER transcript. However, three ER- cell lines (BT-20, MDA-MB-330 and T47Dco) expressed both wild-type and variant transcripts. A differential pattern of expression of wild type to variant was seen in both ER+ and ER- cell lines, however this pattern was not paralleled by differences in ligand-binding activity. Breast tumour cell lines previously classified as ER- expressed significantly lower levels of ER transcripts than did their ER+ counterparts. In view of these findings, as well as earlier reports that the exon 5 deletion ER variant encodes a dominant-positive receptor, it seems clear that some cell lines are misclassified as ER-, and express both wild-type and variant ER mRNAs, and that the overexpression of this variant may account, in part, for their oestrogen-independent phenotype.
Br J Cancer 1995 May
PMID:Coexpression of wild-type and variant oestrogen receptor mRNAs in a panel of human breast cancer cell lines. 773 23

To determine the molecular distinction between invasive and non-invasive pituitary adenomas, we evaluated expression of the metastasizing suppressor gene, nm23, in tumors of varying stages. The nm23 gene was recently identified on the basis of reduced expression in highly metastic cancer compared with its expression in low metastatic potential tumors. Twenty-two pituitary tumors (10 nonfunctioning, 9 acromegaly, 2 prolactinomas, and 1 Cushing) were studied. H1 and H2 isoform expression of nm23 was investigated using a ribonuclease protection assay. nm23 H2 messenger ribonucleic acid expression was significantly reduced in invasive tumors and correlated highly (P = 0.0016) with cavernous sinus invasion. In these invasive tumors, sequencing of the nm23 gene did not reveal a mutation. Invasive tumors also demonstrated markedly reduced immunostaining for nm23 H2. These results show the relevance of nm23 gene expression to behavior of these benign tumors. High expression of nm23 H2 is associated with noninvasive pituitary adenomas and may restrain tumor aggression. This molecular defect distinguishing invasive from noninvasive tumors is shown to be a sensitive marker of adenoma invasiveness and may be a predictor for postoperative management plans.
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PMID:Purine-binding factor (nm23) gene expression in pituitary tumors: marker of adenoma invasiveness. 774 27

Autocrine expression of polypeptide growth factors may be important in the growth regulation of cancer cells. Different growth factor activities have been identified in a variety of tumors. This article describes a case of malignant ascites in a patient recently treated for breast cancer. The use of growth factor mRNA expression as a factor to differentiate between breast and ovarian origins of cancer cells contained in malignant ascites was examined. Expression of insulin-like growth factor-I (IGF-I), IGF-II, and transforming growth factor alpha mRNA was examined by ribonuclease protection assay. The tumor cells expressed IGF-II and transforming growth factor alpha, but not IGF-I mRNA. This pattern of growth factor expression is compatible with a breast cancer primary of the malignant cells contained in the ascites fluid. Therefore, IGF-I mRNA expression may be useful in distinguishing between adenocarcinomas of breast or ovarian origins.
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PMID:Case report: use of insulin-like growth factor-I gene expression to distinguish between breast and ovarian cancer. 814 Nov 35


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