In vivo effects of olive oil and trans-fatty acids on miR-134, miR-132, miR-124-1, miR-9-3 and mTORC1 gene expression in a DMBA-treated mouse model.

Both the intake of beneficial olive oil and of harmful trans-fatty acids (TFAs) in consumed foods are of great significance in tumor biology. In our present study we examined the effects they exert on the expression patterns of miR-134, miR-132, miR-124-1, miR-9-3 and mTOR in the liver, spleen and kidney of mice treated with 7,12-dimethylbenz [a] anthracene (DMBA). Feeding of TFA-containing diet significantly increased the expression of all studied miRs and mTORC1 in all organs examined, except the expression of mTORC1 in the spleen and kidney. Diet containing olive oil significantly reduced the expression of miR-124-1, miR-9-3 and mTORC1 in the liver and spleen. In the kidney, apart from the mTORC1 gene, the expression of all miRs examined significantly decreased compared to the DMBA control. According to our results, the cell membrane protective, antioxidant, and anti-inflammatory effects of olive oil and the cell membrane damaging, inflammatory, and carcinogenic properties of TFA suggest negative feedback regulatory mechanisms. In contrast to our expectations, mTORC1 gene expression in the kidney has not been shown to be an appropriate biomarker-presumably, because the many complex effects that regulate mTOR expression may quench each other.