Bioactivity of skeletal muscle proteolysis-inducing factors in the plasma proteins from cancer patients with weight loss

ABSTRACT We determined the circulating level of bioactivity for skeletal muscle proteolysis-inducing factors (PIF) in the blood samples from cancer patients whose body weight loss was

greater than 10%. The level of bioactivity was estimated by measurement of tyrosine release from isolated 1at diaphragm muscles incubated with an ultrafiltered fraction of plasma or serum

proteins containing molecules from 0 to 25 kDa in molecular weight. Significant levels of bioactivity were detected in 25 of the 50 cancer samples. No activity was found in 18 of the samples

from healthy human blood donors. The ability of 13 of the cancer samples to induce muscle proteolysis was significantly inhibited by incubation of muscles in presence of indomethacin (10

microM). The neutralisation of 12 of the cancer samples with the antibodies to recombinant human interleukin-1 (IL-1), alpha and beta forms, partially abrogated the activity in five samples.

These results suggest that the accelerated breakdown of proteins induced by the cancer plasma factors is at least in part mediated by IL-1 in cooperation with other active factors not yet

defined. Additionally, we have shown that the increased breakdown of proteins induced by PIF in the crude supernatant derived from activated mouse peritoneal macrophages is prevented by the

treatment of muscles with either indomethacin or quin-2 (1 microM). These observations provide indirect evidence for a possible causal relationship between the production of PIF and the

body-weight loss of cancer patients. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution ACCESS OPTIONS Access through

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Read our FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS EFFECTS OF PROTEIN INTAKE FROM AN ENERGY-RESTRICTED DIET ON THE SKELETAL MUSCLE COMPOSITION OF OVERWEIGHT AND

OBESE RATS Article Open access 27 November 2022 ACUTE EFFECT OF HIGH-INTENSITY INTERVAL AEROBIC EXERCISE ON SERUM MYOKINE LEVELS AND RESULTING TUMOUR-SUPPRESSIVE EFFECT IN TRAINED PATIENTS

WITH ADVANCED PROSTATE CANCER Article 29 November 2022 EXERCISE-INDUCED MYOKINES AND THEIR EFFECT ON PROSTATE CANCER Article 22 June 2021 AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Centro

de Biotecnologia, Instituto Butantan, São Paulo, Brazil JE Belizario Authors * JE Belizario View author publications You can also search for this author inPubMed Google Scholar * M Katz

View author publications You can also search for this author inPubMed Google Scholar * E Chenker View author publications You can also search for this author inPubMed Google Scholar * I Raw

View author publications You can also search for this author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Belizario, J., Katz,

M., Chenker, E. _et al._ Bioactivity of skeletal muscle proteolysis-inducing factors in the plasma proteins from cancer patients with weight loss. _Br J Cancer_ 63, 705–710 (1991).

https://doi.org/10.1038/bjc.1991.159 Download citation * Issue Date: 01 May 1991 * DOI: https://doi.org/10.1038/bjc.1991.159 SHARE THIS ARTICLE Anyone you share the following link with will

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