Influence of Tobacco Smoke Exposure on the Protein Expression of α7 and α4 Nicotinic Acetylcholine Receptors in Squamous Cell Carcinoma Tumors of the Upper Aerodigestive Tract (Out of the Larynx)

Abstract

Purpose: To assess protein expression of α7 and α4 nicotinic acetylcholine receptors (nAChR) subtypes in squamous cell carcinoma of the upper aerodigestive track (out of the larynx) according to tobacco smoke exposure, considering the general characteristics of the patients. Methods: The α7 and α4 nAChR subtypes were assessed by immunohistochemistry in tumor samples from 33 patients with novel diagnosis of squamous cell carcinoma of the upper aerodigestive tract (out of the larynx). Results: Current smokers were middle-age men with alcohol consumption, whereas elderly women with no alcohol consumption prevailed among nonsmokers. Expression of α4 nAChR was high in all groups, with an influence of alcohol use, although expression of α7 nAChR was low in current smokers with alcohol use. Expression of α4 with no expression of α7 nAChR was associated with advanced disease. Conclusions: Squamous cell carcinoma tumors of the upper aerodigestive tract (out of the larynx) may show desensitization of α4 nAChR. Advanced disease at diagnosis might be associated with desensitization of α4 with decrease in α7 nAChR.