Effect of a tumour-produced lipid-mobilizing factor on protein synthesis and degradation


Treatment of murine myoblasts, myotubes and tumour cells with a tumour-produced lipid mobilizing factor (LMF), caused a concentration-dependent stimulation of protein synthesis, within a 24 h period. There was no effect on cell number or [3H] thymidine incorporation, but a similar concentration-dependent stimulation of 2-deoxyglucose uptake. LMF produced an increase in intracellular cyclic AMP levels, which was linearly (r2 = 0.973) related to the increase in protein synthesis. The effect of LMF was attenuated by the adenylate cyclase inhibitor MDL12330A, and was additive with the stimulation produced by forskolin. Both propranolol (10 μM) and the specific β3-adrenergic receptor antagonist SR 59230A (10-5M), significantly reduced the stimulation of protein synthesis induced by LMF. Protein synthesis was also increased by 69% (P = 0.006) in soleus muscles of mice administered LMF, while there was a 26% decrease in protein degradation (P = 0.03). While LMF had no effect on the lysosomal enzymes, cathepsins B and L, there was a decrease in proteasome activity, as determined both by the 'chymotrypsin-like' enzyme activity, as well as expression of proteasome α-type subunits, determined by Western blotting. These results show that in addition to its lipid-mobilizing activity LMF also increases protein accumulation in skeletal muscle both by an increase in protein synthesis and a decrease in protein catabolism. © 2001 Cancer Research Campaign.

Publication DOI: https://doi.org/10.1054/bjoc.2001.1834
Divisions: College of Health & Life Sciences > Aston Pharmacy School
College of Health & Life Sciences
College of Health & Life Sciences > Chronic and Communicable Conditions
Additional Information: From twelve months after its original publication, this work is licensed under the Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/
Uncontrolled Keywords: lipid mobilizing factor,protein synthesis,cyclic AMP,b-adrenergic receptor,Cancer Research,Oncology
Publication ISSN: 1532-1827
Last Modified: 03 Jun 2024 07:07
Date Deposited: 19 Aug 2019 08:49
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
http://www.natu ... s/6691834a.html (Publisher URL)
PURE Output Type: Article
Published Date: 2001-06-15
Authors: Islam-Ali, B.S.
Tisdale, Michael J.

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