Retinoids are signaling molecules that control a wide variety of cellular processes and possess antitumor activity. This work presents a comprehensive description of changes in the expression of 23 genes that regulate retinoid metabolism and signaling in non-small-cell lung cancer tumors compared to adjacent normal tissues obtained using RT-PCR. Even at early stages of malignant transformation, a significant decrease in ADH1B, ADH3, RDHL, and RALDH1 mRNA levels was observed in 82, 79, 73, and 64% of tumor specimens, respectively, and a considerable increase in AKR1B10 mRNA content was observed in 80% of tumors. Dramatic changes in the levels of these mRNAs can impair the synthesis of all-trans retinoic acid, a key natural regulatory retinoid. Apart from that, it was found that mRNA levels of nuclear retinoid receptor genes RXRγ, RARα, RXRα, and gene RDH11 were significantly decreased in 80, 67, 57, and 66% of tumor specimens, respectively. Thus, neoplastic transformation of lung tissue cells is accompanied with deregulated expression of key genes of retinoid metabolism and function.
Keywords: biosynthesis of retinoic acid; gene expression; nonsmall-cell lung cancer; retinoid metabolism; retinoid receptor genes.