sepharose and Sarcoma

Topics: Humans; Magnetic Resonance Imaging; Multiparametric Magnetic Resonance Imaging; Prospective Studies; Sarcoma; Sepharose; Soft Tissue Neoplasms

Twenty-three of 36 (64%) lung cancer patients, 19 of 36 (54%) melanoma patients and 18 of 27 (66%) sarcoma patients tested in the leukocyte migration in agarose assay against soluble extracts of histologically similar tumors showed significant inhibition of leukocyte migration. Reactivity to extracts of dissimilar tumors was low. Sera of only 1/13 (7%) lung cancer patients, 2/19 (10%) melanoma patients and 7/21 (33%) sarcoma patients were inhibited by extracts of histologically dissimilar tumors. Only 7-9% of cancer patients reacted to paired extracts of normal tissue from the tumor donors. An average of 13% of sera from normal controls reacted to tumor extracts. Stage of disease and mode of therapy appeared to have little effect on overall reactivity in this assay, although the number of patients within the various categories was small for purposes of statistical analysis. The leukocyte migration in agarose assay shows a sensitivity and specificity to tumor-associated antigens comparable to that of the older capillary tube method in general use and may facilitate performance of migration inhibition. This assay may not be useful as a prognostic test due to the lack ofcorrelation with stage of disease and treatment modality. However, its high specificity and economical use of tumor antigen suggest applications in tumor antigen purification. The use of soluble tumor antigen preparations may make it possible to purify these antigens further to increase specificity and reactivity.

Topics: Antigens, Neoplasm; Cell Migration Inhibition; Epitopes; Humans; Leukocytes; Lung Neoplasms; Melanoma; Sarcoma; Sepharose

An insoluble preparation of rat liver cathepsin D was obtained by coupling the enzyme to Enzacryl Polyacetal (EPA-cathepsin) and to CNBr-activated Sepharose 4B. EPA-cathepsin was active toward the synthetic hexapeptides (Gly-Phe-Leu)2 and did not split hemoglobin. The optimum pH of splitting was displaced upward by 1.5 units to pH 5.0. The enzyme exhibited maximum activity at 60 degrees C. No appreciable loss of activity was seen on storage of the enzyme for 4 months or after repeated use of the preparations. Coupling of rat liver cathepsin D to activated Sepharose gave preparations active towards both protein and synthetic substrates. The preparations were totally inactive in acid media and exhibited maximum activity at pH 7.0, that is, under physiological conditions. Optimum temperature was 65 degrees. The specific activity of the preparations (pH 7.0, 65 degrees) was 60-110 percent that of the free enzyme in acid media. Proteolytic activity of the Sepharose-coupled cathepsin D was not inhibited by pepstatin, whereas that of the free enzyme was fully inhibited by this reagent. A sarcoma cathepsin, similar in some of its properties to the rat liver enzyme, was also coupled to CNBr-activated Sepharose 4B. The preparation split protein substrates at pH 7.0 and possessed enhanced thermostability. The enzymes fixed on Sepharose showed increased stability.

Topics: Acetals; Animals; Carrier Proteins; Cathepsins; Drug Stability; Enzyme Activation; Hemoglobins; Hydrogen-Ion Concentration; Liver; Peptides; Rats; Sarcoma; Sepharose; Spectrophotometry; Temperature