Anorexic syndrome develops in cancer patients at a high incidence, which often involves disturbances in taste and smell as well as the loss of appetite and increased satiety. It has been reported that sweet stimuli increase cAMP level in taste receptor cells. This study was conducted to determine if preference for sweet is altered in anorectic tumor mice and if this behavioral alteration correlates with the sweet signal transduction in their taste receptor cells. Mice bearing a human oral squamous cell carcinoma were subjected to unconditioned taste preference test for a sweet solution (0.2% saccharine, 50% glucose) at three different times after tumor inoculation. Tissue sections containing the circumvallate papillae of tumor bearing mouse were processed for immunohistochemistry with specific antibodies against the activated form of cAMP response element-binding protein (pCREB). Anorexia developed as along with tumor growth, and sweet preference of tumor mice tended to decline in a time dependent manner after tumor inoculation. pCREB immuno-positive nuclei in the taste buds of circumvallate papillae increased in tumor bearing mice, compared to non-tumor controls. These results suggest that preference for sweet may decrease with advanced tumor growth in this mouse model of cancer anorexia, and this reduction may correlate with a basal increase in CREB activity, which perhaps plays a suppressive role in the sweet transduction pathway in taste receptor cells of cancer subjects.

Keywords: Cancer anorexia, taste preference, food intake, pCREB