Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A comparative study of large cell lymphoma (LCL) (ten B and ten T), Hodgkin's disease (15 cases), and true histiocytic lymphoma (two cases) was undertaken, using formalin-fixed paraffin-embedded tissue sections, a panel of eight antibodies, and one lectin to determine if any particular antibody or immunologic profile could reliably distinguish between these entities. The antibodies used were against Leu-M1, alpha-1-anti-chymotrypsin (alpha-ACT), alpha-anti-trypsin (alpha-AT), lysozyme, kappa, lambda, leukocyte common antigen (LCA), and S-100 protein. The lectin used was peanut agglutinin (PNA). Although Leu-M1 staining was positive in 11 of 15 cases (73%) of Hodgkin's disease, it was also positive in 4 of 10 cases (40%) of T-cell lymphoma, 2 of 10 cases (20%) of B-cell lymphoma, and 1 of 2 cases (50%) of true histiocytic lymphoma. Peanut-agglutinin staining results were similar to Leu-M1. The only staining profile that emerged was the presence of Leu-M1, PNA-, alpha-ACT, and alpha-AT staining in Reed-Sternberg (RS) cells in 11 of 15 cases of Hodgkin's disease. Leu-M1 and its staining pattern is characteristic, but not entirely specific for RS cells, and it was not positive in at least 25% of the cases of Hodgkin's disease in formalin-fixed, paraffin-embedded tissues. The limitations of this antibody and others should be recognized.
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PMID:A comparative marker study of large cell lymphoma, Hodgkin's disease, and true histiocytic lymphoma in paraffin-embedded tissue. 294 20

The human monocytic leukemia cell line THP-1 produces an immunosuppressive factor that inhibits interleukin 1 (IL-1)-dependent proliferation of mouse thymocytes as well as the mitogenic effects of concanavalin A (Con A) and phytohemagglutinin (PHA) on human peripheral blood mononuclear cells. The mechanism of action of this factor includes interference with both the production of interleukin 2 (IL-2) and its effects on target cells. Thus, the suppressor abrogates the proliferation of an IL-2-dependent cytotoxic T cell line (CTLL), but not of IL-2 independent cells like the L929 fibroblasts or the EL4 T lymphoma and U937 histiocytic lymphoma lines. It also suppresses IL-2 production by human peripheral blood enriched T cells and mouse splenocytes. The mediator has a molecular weight of 60,000-70,000 dalton, as determined by gel filtration chromatography, is heat labile, and is sensitive to trypsin, chymotrypsin, and protease.
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PMID:A macrophage-derived factor that inhibits the production and action of interleukin 2. 389 22

We report the purification of a protease from tumor cells undergoing apoptosis that is involved in activating DNA fragmentation. Initial studies revealed that two inhibitors of serine proteases, N-1-tosylamide-2-phenylethylchloromethyl ketone and carbobenzoxy-Ala-Ala-borophe (DK120), suppressed tumor necrosis factor or ultraviolet (UV) light-induced DNA fragmentation in the U937 histiocytic lymphoma as well as UV light-induced DNA fragmentation in the BT-20 breast carcinoma, HL-60 myelocytic leukemia, and 3T3 fibroblasts. The protease was purified by affinity chromatography with DK120 as ligand and showed high activity on a synthetic substrate preferred by elastase-like enzymes (Ala-Ala-Pro-Val p-nitroanilide), but was inactive on the trypsin substrate, N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester, or the chymotrypsin substrate, Ala-Ala-Pro-Phe p-nitroanilide. The activity of the DK120-binding protease purified from U937 cells undergoing apoptosis was increased approximately 10-fold over that recovered from normal cells. Further purification to homogeneity by heparin-Sepharose affinity chromatography followed by reverse phase high-performance liquid chromatography revealed a single band of 24 kD on a silver-stained sodium dodecyl sulfate gel. In addition to protease activity, the purified enzyme induced DNA fragmentation into multiples of 180 basepairs in isolated U937 nuclei. These findings suggest the 24-kD protease is a novel enzyme that activates DNA fragmentation in U937 cells undergoing apoptosis.
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PMID:Purification of a 24-kD protease from apoptotic tumor cells that activates DNA fragmentation. 796 87