DIETARY LIPIDS CHANGE THE EXPRESSION OF A PROLIFERATION MARKER IN MURINE 9,10‐DIMETHYL‐1,2‐BENZANTHRACENE‐INDUCED SALIVARY TUMORS

Salivary tumors were induced by 9,10-dimethyl-1,2-benzanthracene injection into the submandibulary gland of mice fed with different dietary lipids. Tumor tissue from 10 mice fed with diets containing corn oil (CO) or fish oil (FO) were immunohistochemically stained for Cx26, β- and γ-catenin, BAX, Bcl-2 and Ki-67. The percentage of animals showing different levels of biomarker expression in epithelial, mesenchymal and stromal cells was calculated in each group. The number of nuclei positive for Ki-67 per 500 total cells was calculated. Reduced expression of Cx26 was observed in FO group as compared to CO. The staining was similar for β-catenin, γ-catenin, BAX and Bcl-2 in both groups. The Ki-67 labeling index was significantly different for CO and FO (0.45–0.40, P < 0.0008). The lower expression of Ki-67 in FO mice could indicate less cellular proliferation. PRACTICAL APPLICATIONS Dietary fatty acids (FAs) affect tumorigenesis. This study examines the effect of dietary lipids on proliferation, apoptosis, cell adhesion and intercellular communication level change during tumorigenesis. Since dietary lipids may be protective or act as promoters of tumorigenesis, the beneficial and negative effects of different FAs could help inform nutrition recommendations directed to the population.