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:2.7.7.7 (DNA polymerase)
17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A fibroblast-like cell culture was established from a stomach biopsy of a patient with metastatic adenocarcinoma. One of the cultures, at the 6th passage level, left unattended for a month at 37 degrees, produced numerous foci of epithelioid cells. Upon subculturing, an epithelioid cell line, designated HCCL (human carcinoma cell line), was established. The HCCL cells released particles possessing the characteristics of oncornaviruses: density 1.175 g/ml, cores with a density of 1.22-1.26 g/ml, high-molecular-weight RNA (60-70S) and RNA-instructed DNA polymerase activity (deoxynucleosidetriphosphate:DNA deoxynucleotidyltransferase, EC 2.7.7.7). Inoculation of particles released from HCCL cells into cultures of human embryo muscle fibroblasts resulted in the appearance of foci of transformed cells.
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PMID:Transformation of cultured human embryonic fibroblasts by oncornavirus-like particles released from a human carcinoma cell line. 5 57

Human mammary carcinoma cell cultures proliferated from primary explants in Eagle's essential medium (MEM) supplemented with insulin, fetal calf serum (FCS) and/or human alpha-a1-antitrypsin. Human mammary carcinoma cells differed from normal mammary epithelial cells by the following catalytic activities: a. Thymidine uptake into the carcinoma cells was 6 to 10 fold greater, whereas thymidine conversion to CO2 was half to one fifth that of normal cells. b. The nucleolytic activity patterns of the mammary carcinoma cells preferred polycytydylic acid and double helical polynucleotides, whereas those of the normal mammary cells preferred polyuridylic acid and had no effect on double helical polynucleotides. c. The polymerase activity most evident in mammary carcinoma cells is a hybrid-dependent DNA polymerase which is guided by the ribo-strand of the template poly (rA) . poly(dT). In contrast the all-ribo template poly (rA) . poly(rU) showed little activity. d. There was slight or statistically non-significant difference between the amino acid composition of material cleaved from mammary carcinoma cells prepared from tumor tissues and from cells cultivated 10 months in vitro. e. There was no difference between the molar proportions of the carbohydrate components of the cell membrane from fresh tumor tissue and long term in vitro cultivated cells. f. The granules from long term in vitro cultured mammary carcinoma cells contained high collagenolytic, caseinolytic, fibrinolytic and esterolytic activities.
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PMID:Long-term cultivation of human mammary carcionoma: proliferation and differential biochemical properties of the cultured cells. 51 50

This study was undertaken to determine whether human papillomavirus (HPV) E6/E7 gene transcription in tonsillar carcinomas is correlated with viral DNA integration. Therefore, tonsillar carcinomas containing HPV-16 (n = 2) and HPV-33 (n = 2) DNA were analysed for the viral physical state and transcription of the E6/E7 region. Southern blot analysis, DNA polymerase chain reaction (PCR) and, eventually, two-dimensional gel electrophoresis revealed indications for the presence of only episomal DNA in the HPV-16-containing biopsies and only integrated DNA in one HPV-33-containing biopsy. The second HPV-33-containing carcinoma, from which one biopsy and two resected tumour specimens were analysed, showed a rather complex physical state profile. The biopsy of this tumour contained only episomal DNA, one resected tumour part contained only integrated DNA and the remaining tumour part contained both integrated and episomal HPV-33 DNA. Independent of the viral physical state, all biopsies and resected tumour parts tested showed the presence of E6/E7 transcripts as determined by RNA PCR. The results indicate that E6/E7 transcripts in tonsillar carcinomas can originate from integrated as well as episomal HPV DNA.
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PMID:Human papillomavirus (HPV) type 16 and 33 E6/E7 region transcripts in tonsillar carcinomas can originate from integrated and episomal HPV DNA. 132 62

In recent years, human papillomavirus (HPV) infection in female genital organs has attracted increasing attention because of its association with lesions in the uterine cervix, especially cervical carcinoma. In this study, the author attempted to determine the presence or absence of HPV infection in the cervical region by means of the polymerase chain reaction (PCR) method, which has become practical thanks to the development of thermostable DNA polymerase, and compared this method with traditional Southern blotting. Moreover, we conducted PCR after detecting DNA by two methods: target punch biopsy and cervicovaginal lavage, and compared the results in terms of detection. 1. The results of HPV detection from the isolated tissue were compared with those of traditional Southern blotting and PCR combined with subsequent hybridization under high stringency (PCR-H). Among the cases that showed negative response with the former method, two of six specimens of cervical carcinoma tissue, and four of eight specimens of normal cervical tissue yielded a positive response as a result of hybridization under low stringency after PCR (PCR-L). HPV was investigated in 56 clinical specimens by PCR. PCR-L was positive in 50.0% and 20.0% of the specimens of cervical carcinoma and normal cervical tissue, respectively. With PCR-H, the positive rates were 37.5% and 7.5% in cervical carcinoma and normal cervical tissue, respectively. 2. Among CIN patients who were followed up at the outpatient clinic, PCR was conducted in specimens obtained by cervicovaginal lavage and target punch biopsy, and the rates of HPV detection were compared.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Detection of human papillomavirus DNA in uterine cervix by polymerase chain reaction (PCR) method]. 132 83

A major family of polyadenylylated cytoplasmic transcripts are expressed from the BamHI A-I region of the Epstein-Barr virus genome, off the strand complementary to that encoding several functions associated with viral replication and the lytic cycle, including the DNA polymerase (BALF-5). These complementary-strand transcripts (the main one is about 4.8 kilobases long), expressed in all cell types associated with Epstein-Barr virus, are present at high levels in nasopharyngeal carcinoma tumors. Sequence analysis of clones that correspond to spliced transcripts in a cDNA library from such a tumor, C15, generates a profile of the main complementary mRNA. It contains at least three AUG-initiated open reading frames, the largest of which could be translated to give a polypeptide of about 20 kDa. Evidence from several types of experiments suggests that conditions which support the up (or down) regulation of transcriptional expression from one viral DNA strand within the relevant region of the genome produce the opposite effect on transcripts from the other strand. The capacity for interference between complementary Epstein-Barr viral transcripts offers a mechanism for control of gene expression that may be related to maintenance of viral latency.
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PMID:Expression of a family of complementary-strand transcripts in Epstein-Barr virus-infected cells. 132 42

The distribution of proliferating cells was studied in colorectal carcinoma by immunohistochemistry using monoclonal antibody-DNA polymerase alpha and Ki-67. Colorectal carcinoma was classified into two types by growth mode: (1) intramucosal polypoid growth carcinoma and (2) non-polypoid growth carcinoma. The labeling index of anti-DNA polymerase alpha and Ki-67 in non-polypoid growth carcinoma was significantly higher than in polypoid growth carcinoma. The labeling index of polypoid growth carcinoma was significantly higher than adenoma. The proliferating cells in polypoid growth carcinoma and adenoma were mainly distributed in the upper third of intramucosal neoplastic gland. However, in non-polypoid growth carcinoma, the proliferating cells of intramucosal lesion were scattered mainly in the lower third along the neoplastic gland. The distribution pattern of proliferating cells in early carcinoma with non-polypoid growth were similar to those of non-polypoid growth advanced carcinoma. These results suggested that submucosal invasion occurred more rapidly in intramucosal non-polypoid growth carcinoma.
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PMID:[Immunohistochemical study of proliferative cells in colorectal adenoma and carcinoma]. 146 Jul 66

Cell renewal in the large intestine mucosa is normally tied to a rigidly compartmentalized model. Immunohistochemical identification of cells in S phase through uptake of bromodeoxyuridine is the method of choice for detailed compartmental mapping of proliferation, while immunohistochemical detection of proliferation-associated antigens (Ki-67, PCNA, DNA polymerase alpha) provides information in advanced tumor cases. Mucosal hyperproliferation due to inflammation may be transient (self-limited colitis, Crohn's disease, acute radiation damage) or lasting (ulcerative colitis). Progressive shifting of the proliferation zone to the crypt surface (Stage II abnormality) is a late feature of irradiated rectal mucosa and subgroups of ulcerative colitis patients at high risk for cancer. Hyperproliferation and Stage II abnormality coexist in the mucosa of patients with colorectal neoplasia, but are mutually independent and correlated to different clinical and pathological features of the disease. These cytokinetic abnormalities are highly predictive markers of the adenoma-carcinoma sequence, but are not associated with de novo adenocarcinoma. Proliferation increases progressively in the subsequent steps of this sequence, except in early cancer.
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PMID:Cell proliferation in colorectal tumor progression: an immunohistochemical approach to intermediate biomarkers. 146 8

The sugar boronated thymidine nucleoside, 5' -0-[(triphenylphosphine-boryl) carbonyl]-3'-0-acetyl thymidine 1, and the boron-modified nucleoside phosphotriester, 5'-(diethylphosphite- cyanoborane)-3'-acetylthymidine 2, were successfully synthesized. Both compounds demonstrated differential activity when tested against eight cell lines, with significant cytotoxic activity against the growth of human Tmolt3 leukemia, colon adenocarcinoma, HeLa S3 uterine carcinoma, and osteosarcoma cells. In in vivo studies these agents were found to be active against the growth of Ehrlich ascites carcinoma at 8 mg/kg/day I.P. and to be marginally active against the growth of L1210 and Lewis lung cancers in mice. The mode of action of these thymidine derivatives in Tmolt3 cells was the inhibition of DNA and protein synthesis. Compound 2 was highly effective in inhibiting DNA polymerase alpha and m-RNA, r-RNA and t-RNA polymerase activities. Both compounds inhibited ribonucleoside reductase activity. The de novo purine pathway appeared to be the major site of inhibition of the agents, with IMP dehydrogenase, PRPP amido transferase, and dihydrofolate reductase activities being significantly inhibited. In the pyrimidine pathway, carbamyl phosphate synthetase and aspartate transcarbamylase activities were inhibited by 1. As expected, d[NTP] levels were significantly reduced by treatment with the agents. DNA strand scission was evident after incubating Tmolt3 cells for 24 hr with the agents.
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PMID:Antineoplastic activity of boron-containing thymidine nucleosides in Tmolt3 leukemic cells. 150 1

Proliferating cell nuclear antigen (PCNA) is a 36-kDa DNA polymerase-delta auxiliary protein which accumulates in the nucleus during S phase of the cell cycle. Immunohistochemical labeling indices (LI) of PCNA and Ki-67 were compared using an avidin-biotin complex method on frozen sections of 27 nervous system tumors. 3 normal cerebral cortices, and 3 peripheral nerves. In glial tumors, PCNA and Ki-67 LI increased with increasing tumor grade (Daumas-Duport system). In 5 low-grade glial tumors, PCNA and Ki-67 LI were less than or equal to 1%, except for one optic nerve glioma (Ki-67 LI = 6%). In 7 grade 3 astrocytomas and 1 mixed glioma, PCNA LI were less than or equal to 1-1.5%, while Ki-67 LI were 2%-10%. In 7 grade 4 astrocytomas and 1 metastatic carcinoma, PCNA LI ranged from 6%-15% while Ki-67 LI ranged from 17%-30%. In 5 of 6 schwannomas, focally high PCNA LI (4%-65%) were noted, despite low LI with Ki-67 (less than or equal to 1.6%). Scattered normal schwann cell nuclei also stained with PCNA, but normal cerebral cortex did not.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Proliferating cell nuclear antigen and Ki-67 immunohistochemistry in brain tumors: a comparative study. 167 78

In order to identify the gene encoding the Epstein-Barr virus (EBV) DNA polymerase, a portion of the BamHI-A fragment containing the fifth leftward open reading frame (BALF5) of the EBV genome was cloned into SP6 and T7 promoter-containing vectors for in vitro transcription-translation. The RNA synthesized in vitro was used to program rabbit reticulocyte lysates, which were analyzed for the synthesis of the putative polymerase polypeptide (110 kDa) and assayed directly for EBV DNA polymerase activity. The polypeptide synthesized by the full-length BALF5 genomic fragment had a molecular mass of 110 kDa. 5'-truncated BALF5 with the first and second ATGs deleted produced 95- and 83-kDa polypeptides, respectively. All three translation products were enzymatically active and displayed resistance to high salt concentrations. The identity of the largest polypeptide as the viral polymerase was established by (i) immunoprecipitation with EBV-positive sera from patients with nasopharyngeal carcinoma and by a rabbit polyclonal antiserum prepared with a synthetic peptide derived from the DNA sequence of BALF5; (ii) identification of a polypeptide of identical size (110 kDa) immunoprecipitated from superinfected Raji cell extracts by these antibodies; and (iii) salt-resistant enzymatic activity which was neutralized by the rabbit EBV antiserum. Thus, BALF5 encodes a functional polymerase identical to that induced in superinfected Raji cells.
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PMID:Identification and functional characterization of Epstein-Barr virus DNA polymerase by in vitro transcription-translation of a cloned gene. 185 46


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