Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fifty cases of colorectal adenocarcinoma were immunohistochemically examined for the relationship between distribution of plasminogen activators (PAs) and the degree of differentiation of cancer cells as reflected by carcinoembryonic antigen (CEA) expression as well as tumor cell kinetics. The A chain of urokinase-type PA (u-PA-A) was mainly observed in the apical portions of highly differentiated cancer cells. Increased expression and change in localization to the cytoplasm were found with progressive dedifferentiation. The numbers of DNA polymerase alpha (pol. alpha) positive cancer cells also increased in line with u-PA-A expression. The B chain of u-PA (u-PA-B), and the A and B chains of tissue-type PA (t-PA-A and -B) did not show similar alteration. The present findings suggest that the distribution of u-PA-A in colorectal carcinoma tissues, the degree of tumor differentiation, and the proliferation kinetics of cancer cells are closely related.
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PMID:Immunohistochemical analysis of plasminogen activator expression in human colorectal carcinomas: correlation with CEA distribution and tumor cell kinetics. 190 Nov 19

The synthesis of the human plasminogen-activator inhibitor 1 (PAI-1) protein in the cytoplasm of transformed Escherichia coli cells results in inactive protein preparations that can be activated by denaturation and renaturation. We have used the phagemid pComb3, designed for combinatorial immunoglobulin repertoire cloning, for routing of PAI-1 to the periplasm and subsequent exposure on the surface of filamentous phages. Phage-displayed PAI-1 specifically binds to immobilized polyclonal and monoclonal anti-human PAI-1 antibodies. In addition, PAI-1 retains its capacity to form equimolar complexes with its target serine protease tissue-type plasminogen activator (t-PA), as well as its ability to inhibit t-PA activity. Finally, we have explored and manipulated the error-prone property of TaqI DNA polymerase during PCR amplification of the full-length PAI-1 cDNA to generate a large library of predominantly single, random PAI-1 mutants. In addition, a computer simulation program has been devised that converts the number of mutations per codogenic region (in this case PAI-1) into actual mutant proteins. The PAI-1-phage mutant library is composed of 46% single and 34% double mutants and 20% wild-type PAI-1 and can be employed to isolate mutants defective in interactions of PAI-1 with other components. The method described here is applicable to other studies on the structure-function analysis of eukaryotic proteins.
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PMID:Functional display of human plasminogen-activator inhibitor 1 (PAI-1) on phages: novel perspectives for structure-function analysis by error-prone DNA synthesis. 850 55

DNA damage results from a wide variety of external agents such as chemicals and radiation. The consequences of exposure to agents that damage DNA have been traditionally studied from the perspective of cell survival and mutagenesis. Mutations are late endpoints of DNA damage. Cells respond to the earlier stages of DNA damage by inducing the expression of several genes, including those specific of the nature of the lesion. These early transcriptional responses are likely to predetermine the later fate of the damaged cell. Genes activated during this early response include those involved in DNA repair, replication, and growth control. We are interested in the transcriptional mechanisms by which cells respond to DNA damaging agents. To facilitate the measurement of gene induction, we used seven different reporter constructs integrated stably into the RKO cell line derived from a human colon carcinoma. These constructs were derived from promoters and/or response elements isolated from genes associated with DNA damage responses in human cells, and were fused to the bacterial reporter gene, choramphenicol acetyl transferase (CAT). The cell lines generated in this manner contain the promoters and/or response elements representing DNA polymerase beta, p53, gadd (growth arrest and DNA damage) 45 and 153, c-fos, TPA response element, and tissue-type plasminogen activator. These recombinant cell lines were assembled in a 96-well microtiter plate permitting their simultaneous exposure to compounds and subsequent CAT protein measurement. This assembly has been designated the CAT-Tox (D) assay. These cell lines were exposed to different classes of DNA damaging agents including those which covalently join bases to form dimers (e.g., UVC irradiation), generate DNA adducts by alkylation (e.g., methylmethane sulfonate [MMS], ethylmethane sulfonate [EMS], N-methyl-N-nitro-N-nitrosoguanine [MNNG], dimethylnitrosamine [DMN]), cross-link DNA (e.g., mitomycin C), and inhibit DNA replication by intercalative (e.g., actinomycin D) and nonintercalative (e.g., hydroxyurea) mechanisms. The transcriptional responses were measured as a function of the accumulation of CAT protein using antibodies against CAT protein in a standard ELISA. Endogenous cellular responses were evaluated for a number of the genes represented in the assay at both the mRNA and protein levels by Northern and Western blot analysis, respectively. These data corroborate the stress-induced responses measured by CAT ELISA in the CAT-Tox (D) assay, demonstrating the usefulness of this assay as a rapid and sensitive method for detection of DNA damaging agents in human cells.
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PMID:Stress responses to DNA damaging agents in the human colon carcinoma cell line, RKO. 895 Mar 45