GPRC5A REGULATION BY VITAMIN D3 AND CIGARETTE EXTRACT SMOKE IN COLON CANCER CELL LINES

IGLESIAS, PABLO; DIB, CAMILA; NUÑEZ, NADIA; LIMPIAS DEL VALLE,TATIANA ; MORI, CONSUELO; VALDIVIESO, Á. GABRIEL; SANTA COLOMA TOMAS A.

Congreso; LXVII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA (SAIC); 2022

GPRC5A is a G protein-coupled receptor 5A, also known as Retinoicacid-induced gene 3 (RAI3) and Retinoic acid-induced (RAIG1). Inour laboratory, we named this gene PEIG-1 (phorbol ester-inducedgene-1) because it was found to be a 12-O-tetradecanoyl phorbol13-acetate (TPA)-inducible gene. Recently, we reported that TPAregulated GPRC5A mainly through the PKC pathway. Commonly,TPA is employed as a tumor-promoting agent. GPC5A dysregulationis associated with diverse types of human cancers and its roleas a tumor suppressor or as an oncogene is unclear yet. This dualbehavior makes GPRC5A an interesting gene to study. The aim ofthis work was to study the expression of this gene in colon (T84 andCaco-2) and lung (Calu-3) cells treated with cigarette extract smoke(CSE), a potential oncogenic inductor. Also, cells were treated withvitamin D3 because of its similar immunomodulatory action thatretinoic acid (vitamin A), a known activator of the promoter regionof GPRC5A through the RAR/RXR transcription factor. The transcriptionalexpression of GPRC5A in cells treated with CSE, vitaminA, vitamin D3, and TPA was measured by qRT-PCR. To test ifROS could be involved in the GPRC5A regulation, the cytoplasmicROS (cROS) and mitochondrial ROS (mtROS) were measured withDCFH-DA and Mitosox, respectively. The mitochondrial membranepotential (mΨ) was measured by flow cytometry with the fluorescentprobe TMRE. The treatment with CSE and vitamin D3 for 48 h inducedan increased (p