Effect of Smoke Exposure on Chronic Inflammation and P53 Expression in Bladder Epithelial

Abstract

Bladder cancer is widely studied for its association with cigarette smoke (CS) exposure. Nicotine and carcinogenic substances in CS could induce chronic inflammatory state and DNA damage. This research was aimed to investigate the effect of CS exposure in chronic inflammatory state and p53 expression in bladder epithelial of Wistar rats. 25 male Wistar rats aged 6-8 weeks were divided into five groups as follows: Control (without treatment); CS-1, CS-2, CS-4, and CS-8 (treated with CS 1x, 2x, 4x, and 8x/day, respectively). Each exposure was done for 15 minutes for 60 days. Chronic inflammatory score was calculated from HE-stained specimens and Immunohistochemistry method was applied to measure p53 expression. Results showed that lymphocyte and histiocyte count in CS-8 was significantly higher as compared to CS-1 (p<0.05) and control (p<0.05). Lymphocyte and histiocyte count in CS-4 was also significantly higher compared to non-treated group (p<0.05). Chronic inflammatory score was significantly higher in CS-8 compared to other group (p<0.05). Moreover, p53 expression was found in CS-8 group (2 of 5 subjects had positive p53 expression, 20 positive cells in from total 10 hpf) and significantly different with other groups (p=0.011). Correlation study showed significant correlation between frequency of cigarette smoking exposure and lymphocyte count (p=0.000; r=0.956); monocyte count (p=0.000; r=0.928); chronic inflammation score (p=0.000; r=0.928); and p53 expression (p=0.007; r=0.522). We concluded that there was significant differences in chronic inflammation state and p53 expression among groups. Correlation study showed that frequency of cigarette smoking exposure was positively correlated with chronic inflammation and p53 expression.