Metabolic and morphological alterations induced by proteolysis-inducing factor from Walker tumour-bearing rats in C2C12myotubesReport as inadecuate

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BMC Cancer

, 8:24

First Online: 28 January 2008Received: 19 April 2007Accepted: 28 January 2008DOI: 10.1186-1471-2407-8-24

Cite this article as: Yano, C.L., Ventrucci, G., Field, W.N. et al. BMC Cancer 2008 8: 24. doi:10.1186-1471-2407-8-24


BackgroundPatients with advanced cancer suffer from cachexia, which is characterised by a marked weight loss, and is invariably associated with the presence of tumoral and humoral factors which are mainly responsible for the depletion of fat stores and muscular tissue.

MethodsIn this work, we used cytotoxicity and enzymatic assays and morphological analysis to examine the effects of a proteolysis-inducing factor PIF-like molecule purified from ascitic fluid of Walker tumour-bearing rats WF, which has been suggested to be responsible for muscle atrophy, on cultured C2C12 muscle cells.

ResultsWF decreased the viability of C2C12 myotubes, especially at concentrations of 20–25 μg.mL. There was an increase in the content of the pro-oxidant malondialdehyde, and a decrease in antioxidant enzyme activity. Myotubes protein synthesis decreased and protein degradation increased together with an enhanced in the chymotrypsin-like enzyme activity, a measure of functional proteasome activity, after treatment with WF. Morphological alterations such as cell retraction and the presence of numerous cells in suspension were observed, particularly at high WF concentrations.

ConclusionThese results indicate that WF has similar effects to those of proteolysis-inducing factor, but is less potent than the latter. Further studies are required to determine the precise role of WF in this experimental model.

AbbreviationsCDNB – 1-chloro-24-dinitrobenzene

DMEM– Dulbecco-s modified Eagle-s medium

ECL– enhanced chemical luminescence FCS – foetal calf serum

GST– glutathione-S-transferase

HB– homogenising buffer

HRP– horse radish peroxide

IL6– interleukin 6

MDA– malondialdehyde

MTT – 3-4,5-dimethylthiozol-2-yl-2,5-diphenyltetrazolium bromide

NAC– Nucleic acid content

NRU– neutral red uptake

PBS– phosphate buffered saline

PIF– proteolysis inducing factor

ROS– reactive oxygen species

SDS-PAGE– sodium dodecyl sulphate polyacrylamide gel electrophoresis

SUC-LLVY-AMC– succinyl-Leu-Leu-Val-Try-7-amino-4-methylcoumarin

TCA– tricloro acetic acid

TNFα– tumour necrosis factor

WF– Walker Factor.

Electronic supplementary materialThe online version of this article doi:10.1186-1471-2407-8-24 contains supplementary material, which is available to authorized users.

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Author: Claudia L Yano - Gislaine Ventrucci - William N Field - Michael J Tisdale - Maria Cristina C Gomes-Marcondes


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