Activation of Thermogenesis in Brown Adipose Tissue and Dysregulated Lipid Metabolism Associated with Cancer Cachexia in Mice

作者:Tsoli Maria*; Moore Melissa; Burg Dominic; Painter Arran; Taylor Ryland; Lockie Sarah H; Turner Nigel; Warren Alessandra; Cooney Greg; Oldfield Brian; Clarke Stephen; Robertson Graham
来源:Cancer Research, 2012, 72(17): 4372-4382.
DOI:10.1158/0008-5472.CAN-11-3536

摘要

Cancer cachexia/anorexia is a complex syndrome that involves profound metabolic imbalances and is directly implicated as a cause of death in at least 20% to 30% of all cancers. Brown adipose tissue (BAT) plays a key role in thermogenesis and energy balance and potentially contributes to the physiologic perturbations associated with cachexia. In this study, we investigated the impact of cachexia-inducing colorectal tumor on BAT in mice. We found that brown adipocytes were smaller and exhibited profound delipidation in cachectic tumor-bearing mice. Diurnal expression profiling of key regulators of lipid accumulation and fatty acid beta-oxidation and their corresponding target genes revealed dramatic molecular changes indicative of active BAT. Increased Ucp1, Pbe, and Cpt1 alpha expression at specific points coincided with higher BAT temperatures during the dark cycle, suggestive of a temporal stimulation of thermogenesis in cachexia. These changes persisted when cachectic mice were acclimatized to 28 degrees C confirming inappropriate stimulation of BAT despite thermoneutrality. Evidence of inflammatory signaling also was observed in the BAT as an energetically wasteful and maladaptive response to anorexia during the development of cachexia. Cancer Res; 72(17); 4372-82.