Description: Microarray studies revealed alterations in the expression of a number of miRNAs in lung tumors relative to that of normal lungs. miR-21, mir-31, miR-130a, miR-146b, and miR-377 were consistently up-regulated, whereas miR-1 and miR-143 were down-regulated in lung tumors relative to normal lungs. In mice treated with VC and given I3C in the diet, levels of miR-21, mir-31, miR-130a, miR-146b, and miR-377 were reduced relative to the level in mice treated with the carcinogen only. The results of the microarray study were confirmed by QRT-PCR and gel analysis of PCR products. Further studies with miR21 indicated that PTEN, PDCD4, and RECK are potential targets for the oncogenic effect of miR-21 and the chemopreventive activity of I3C. Taken together, we showed here that miRNAs are deregulated during VC-induced mouse lung tumorigenesis and their levels are modulated by I3C. Therefore, miRNAs and their target genes are promising biomarkers for the diagnosis of lung cancer and efficacy of chemopreventive/chemotherapeutic agents. |