Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human seminal plasma (SP) has been known to contain both growth-inhibitory and -stimulatory factors. We attempted to identify a factor that inhibited DNA synthesis in some metastatic prostate cancer cell lines. The SP factor was sensitive to digestion by trypsin, but its activity increased after boiling or dialysis against 1 M acetic acid, by 3- to 4-fold. The SP factor was partially purified using a cation-exchange resin. Apparent molecular mass determination by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed it to be a M(r) 25,000 protein, and M(r) 13,000 after reduction. This protein strongly inhibited DNA synthesis in two metastatic androgen-independent human prostatic carcinoma cell lines (PC3 and DU145) and the Dunning R3327G rat prostatic adenocarcinoma. It was ineffective on androgen-dependent LNCaP cells. The proliferation-inhibiting activity of this SP protein was specifically and completely abolished by a neutralizing anti-transforming growth factor beta (TGF-beta) antiserum. Furthermore, immunoblot analysis using the anti-TGF-beta antiserum showed the similarity of this protein to TGF-beta. The maximum concentration of this protein in SP was 165 +/- 11.7 ng/ml (mean +/- SD), of which only one-fourth may be present in active form under normal conditions. Identification of a TGF-beta-like protein in SP might also explain the variety of growth and immune modulation properties of human SP.
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PMID:Isolation of a prostate carcinoma cell proliferation-inhibiting factor from human seminal plasma and its similarity to transforming growth factor beta. 139 10

Cell motility has been associated with metastatic ability in the Dunning R3327 rat prostatic adenocarcinoma model. Cancer cell motility promoters but not inhibitors have been described by many investigators. Serum-containing and serum-free media conditioned by the nonmotile, nonmetastatic G Dunning subline inhibited the motility of the highly motile, highly metastatic MAT-LyLu subline. Motility inhibition by the G subline-conditioned serum-free media was lost upon heating to 100 degrees C and by treatment with trypsin. The motility inhibitory protein(s) had a molecular weight exceeding 50,000 as determined by diafiltration. G subline-conditioned RPMI 1640 contained several proteins with molecular weights of between approximately 53,000 and 116,000 when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. One of these bands may represent the first inhibitor of cancer cell motility identified.
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PMID:Cancer cell motility-inhibitory protein in the Dunning adenocarcinoma model. 155 38

We have systematically analyzed the proliferative properties of the clonogenic cells of the R3327 transplantable rat prostate adenocarcinoma (colony forming units, prostatic adenocarcinoma, CFU-PA). Pronase was determined to be more effective than either trypsin or collagenase in obtaining the largest number of viable cells from a solid R3327 tumor. Digestion with 2.5 mg/ml yielded a maximum of 5.6 X 10(4) CFU-PA/g of tumor tissue, with higher concentrations resulting in s substantially lower fraction of CFU-PA while producing larger overall cell yields. Bacto-agar at 0.35% supported the growth of the largest number of CFU-PA and was sharply concentration dependent with concentrations greater than 0.4% completely suppressing CFU-PA growth. The addition of conditioned medium (CM) from R3327 liquid cell cultures to agar cultures resulted in a specific twofold increase in CFU-PA/10(4) cells, whereas CM from R3327A cells was less effective and CM from rat skin fibroblasts least stimulatory. The addition of washed rat red blood cells (RBC) either within the agar culture itself or in an overlayer was highly stimulatory, resulting in as much as a fivefold increase in CFU-PA to 6 to 8 x 10(4)/g.
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PMID:Proliferative properties of the clonogenic cells of the R3327 prostate adenocarcinoma. 633 74

At present, there is no established diagnostic method by which the metastatic ability of an individual prostatic cancer can be accurately predicted. Metastasis is a multistep process, the first critical step of which is invasion. Tumor invasion has been suggested to involve a variety of hydrolytic enzyme activities; therefore, the tumor levels of these activities might be indicative of the overall metastatic ability of the cancer. In order to evaluate if the quantitative levels of hydrolytic enzymes can be used to predict the metastatic ability of individual prostatic cancers, five different Dunning R-3327 rat prostatic adenocarcinoma sublines, with widely varying metastatic abilities, were assayed for the respective levels of a variety of hydrolytic enzyme activities (collagenase, trypsin-like, cathepsin B, neutral protease, N-acetyl-beta-glucosaminidase, chymotrypsin-like, leucine aminopeptidase, elastase, and plasminogen activator). These studies demonstrated that most hydrolytic activities are not elevated when going from normal prostate to prostatic cancer. In addition, only the levels of elastase and chymotrypsin-like activity were found to be consistently higher in highly metastatic prostatic cancers than in either the normal prostate or low-metastatic prostatic cancers. It was found that, by combining the relative activities of elastase and chymotrypsin-like activity and then dividing by the relative activities of N-acetyl-beta-glucosaminidase, a biochemical metastatic index could be constructed which accurately reflected the respective metastatic ability of the Dunning sublines.
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PMID:Biochemical methods for predicting metastatic ability of prostatic cancer utilizing the dunning R-3327 rat prostatic adenocarcinoma system as a model. 653 99

Extracts of human benign prostatic hyperplasia, well-differentiated prostatic adenocarcinoma, and normal post-pubertal prostate stimulate 3H-thymidine incorporation by resting phase cultures of fetal rat osteoblasts and fibroblasts. The stimulation is concentration dependent and reaches a maximum at twenty-four hours of incubation. Prostatic extracts are also mitogenic in cell cultures of newborn human foreskin fibroblasts and the human cell lines, BUD-8 and DoT. The growth-stimulating factor is both heat and trypsin sensitive indicating that the factor is either a protein or contains a protein moiety. The growth-stimulating activity is not related to prostatic polyamine concentration. Experiments also show the activity is not due to human prostatic acid phosphatase. A prostatic growth factor may explain the growth of fibrous nodules in benign prostatic hyperplasia and the osteoblastic response of bone to prostatic cancer.
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PMID:Mitogenic factor in human prostate extracts. 696 86

Spheroids of the human prostatic adenocarcinoma cell line DU 145 were used to study experimental radioimmunotherapy. Spheroids were incubated with the 131I-labelled monoclonal E4 antibody until the radionuclide immunoconjugate had bound the 5 to 6 outermost cell layers of the spheroids. A set of 50 spheroids were exposed, either immediately or 48 hr after antibody incubation and washings, to a dilute trypsin solution with the aim of stripping off cells from the spheroid surface. Stripped cells were collected in fractions corresponding to defined spherical shells. Cells were subsequently plated for clonogenic growth. The technique of automated sequential trypsinization of spheroids followed by a clonogenic survival assay permits studies on therapeutic efficacy for radionuclide immunoconjugates on cells from different layers of spheroids. In addition, the absorbed doses throughout a spheroid were calculated. The binding and retention kinetics of the radionuclide immunoconjugate and the excess of 131I-E4 in the culture medium during incubation are factors that were all accounted for in the calculations. If the calculated absorbed doses were inserted into the linear-quadratic survival model and the low dose rate was taken into account, survival values were well in accordance with the experimentally obtained values. The results demonstrate that the 131I-labelled E4 antibody is capable of sterilizing cultured tumour cells that have bound the radionuclide immunoconjugate and, by means of radiation "cross-fire", those cells located in close proximity.
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PMID:Radioimmunotherapy of prostatic adenocarcinomas: effects of 131I-labelled E4 antibodies on cells at different depth in DU 145 spheroids. 759 Dec 37