Various dietary polyunsaturated fatty acids modulate acrylamide-induced preneoplatic urothelial proliferation and apoptosis in mice

To investigate whether various dietary fats affected preneoplatic lesions of urinary tract in acrylamide (ACR)-treated mice. Eighty Kunming mice were initiated with ACR at dose 10 mg/kg bw, and fed with different polyunsaturated fatty acid (PUFA): 6% fish oil (enriched in n-3 PUFA), 6% corn oil (enriched in n-6), 6% olein (enriched in n-9, an EFA deficiency inducer), 10% fish oil, 10% corn oil, 10% olein and a commercial chow. Animals were autopsied 22 weeks. The liver fatty acid profile showed a close correlation with dietary sources, exhibiting macroscopic and biochemical EFA-deficient (EFAD) characteristics in ACR mice with olein. The frequency of simple urothelial hyperplasia (H) and dysplasia/carcinoma in situ (D/CIS) was significantly higher in ACR mice with corn oil or olein compared to ACR mice with commercial chow. Proliferation and abnormal luminal localized mitosis, also expression of proliferating cell nuclear antigen (PCNA), significantly increased in ACR mice with corn oil and olein than in ACR mice with commercial chow; moreover, abnormal apoptotic/mitosis ratio, expression of caspase-3, decreased in ACR mice with both olein and corn oil. Fish oil took no significant effect on almost all the parameters in ACR mice in this study. Results suggest that dietary PUFA modulate preneoplastic proliferation in ACR mice; n-6 PUFA (corn oil) and EFAD status (n-9 PUFA) exhibits a promoting activity; whereas, fish oil, rich in n-3 fatty acids, exhibits somewhat attenuated effect, and needs further research.