Effects of edible plant microRNAs on cancer cell proliferation: a beneficial cross-kingdom interaction

Diet in human health is no longer simple nutrition but, in the light of recent findings, it might play a pivotal role on cell health status by modulating apoptosis, detoxification, and appropriate gene response to environmental stresses. Epidemiological studies suggest a role of fruits and vegetables in protection against several diseases, and nutrients have been demonstrated to alter gene expression by DNA methylation and histone modifications [1-2]. Diet has also been found to modulate micro RNA (miRNA) expression, leading to a subsequent regulation of the effectors genes [3]. Furthermore, recent studies demonstrate that some plant/food-derived microRNAs (miRNAs) regulate gene expression in a sequence specific manner [4]. On the basis of all these findings, we have carried out a pilot study, using a combined "in-silico and wet" approach, to investigate the potential effects, and elucidate the molecular mechanisms, of edible plant miRNAs on the expression of human genes involved in cancer onset and progression. In the present paper we report the results obtained by transfecting 2 colon cancer cell lines, p53 wild type and p53 knock-out, with selected miRNAs of G. max, Z. mais and M. truncatula, which we found, by in silico analysis, to have a putative targeting activity on human oncogenes and tumor suppressor genes.