Chemopreventive effects of the polyunsaturated fatty acids omega-3 on the carcinogenesis process of the upper aerodigestive tract induced by 4-nitroquinoline-1-

Chemopreventive effects of the polyunsaturated fatty acids omega-3 on the carcinogenesis process of the upper aerodigestive tract induced by 4-nitroquinoline-1-oxide in Swiss mice

29 Jan 2014

Ricardo Ribeiro Gama, Allan Giovanini, Fernanda Scarmato de Rosa, Daniel Cury Ogata, André Luiz Vettore de Oliveira, Ana Flávia Cardoso Costa, Carolina Talini, Denise Feniman, Douglas Kamei, Celso Felipe Júnior, Allan Coco, André Lopes Carvalho

Objective: To study the potential chemopreventive effects of polyunsaturated fatty acids omega-3 in Swiss mice submitted to oral and oesophageal carcinogenesis induction by 4-nitroquinoline-1-oxide (4-NQO).

Study design: The animals underwent carcinogenesis induction with 50 μg/mL 4-NQO for eight weeks. The animals were divided into groups: Group I—4-NQO induction without chemoprevention, Group II—chemoprevention with the addition of 5% fish oil (FO) in their diet after 4-NQO carcinogenesis induction, and Group III—chemoprevention with 5% FO in their diet during and after 4-NQO carcinogenesis induction.

Results: The incidence of invasive oral carcinoma was: Group I (72.9%), Group II (84.2%), and Group III (64.7%); p = 0.34. The difference in the incidence of invasive oesophageal carcinoma was statistically significant: Group I (37.8%), Group II (68.4%), and Group III (29.4%); p = 0.02.

Conclusions: 4-NQO induction led to cancer in the majority of animals. Chemoprevention with FO brought no benefit in preventing the carcinogenesis process initiated by 4-NQO for oral cancer. The suggestive pro-tumour action of FO when given after tumour post-initiation seems to demonstrate that this fatty acid can potentialise the action of 4-NQO in the oesophagus carcinogenesis of the Swiss mice.