MODULATION OF GENES AND PROTEINS RELATED TO METASTATIC PROCESSES IN RETINOIC ACID SENSITIVE AND RESISTANT BREAST CANCER CELLS

VANDERHOEVEN F.,; CASTRO C,; MONDACA J.;; REDONDO A.,; SÁNCHEZ A.M.,; FLAMINI M.I

San Juan

Congreso; XLI Sociedad de Biología de Cuyo; 2023

Sociedad Biología de Cuyo

Breast cancer (BC) is women's most frequent malignant neoplasia and has a high mortality rate. Alltrans retinoic acid (RA) is a vitaminA derived pleiotropic signaling molecule that regulates critical genetic programs. Although RA has demonstrated a potentanticarcinogenic activity, its use in solid tumors is limited. Previous studies showed that MDA MB 231 , MDA MB 468 T 47D andSK BR3 , BC cell lines have different RA sensitivity and RA growth inhibitory effects. We have previously demonstrated that RAdecreases cell migration in RA sensitive BC cells by reducing the expression of movement fundamental proteins. Furthermore, wedetermined how RA pathway phosphorylates/activates and redistribute s these proteins, ultimately inhibiting BC cell migration.Metalloproteases (MMPs) are proteins involved in the degradation of the extracellular matrix, promoting invasion and metastas is.MMPs are closely related to E Cadherin and Vimentin , protein markers of Epithelial/Mesenchymal Transition (EMT), and their levelsaffect cell adhesion and migration. We propose to characterize target gene expression profiles in RA treated BC cell lines using theGene Expression Omnibus ( public repository and to determine the effect of RA in RA sensitive or resistant BC cells on cellviability and proliferation. We also propose to determine the role in the EMT process. W e performed bioinformatics analysis usingGEO ( GSE103426 to determine differential gene expression in RA resistant cell lines by volcano plots and in vitro experiments toassess the effect of RA on cell viability by MTT assay and protein expression by Western Blot in RA sensitive and RA resistant celllines . Differential g ene expression analysis of controls vs. treated with RA (100 nM, 18 h) MDA MB 231 and MDA MB 468 cellsshowed that RA modulate s migration related gene expression similarly in both lines. Interestingly, genes related to proliferation werenot affected. The viability of MDA MB 231 cells was not reduced after different doses of RA, demonstrating their resistance to RA.In contrast, RA decreased the viability of T 47D cells, confirming their sensitivity to RA We also observed that retinoic acid receptors(RAR α, RAR β and RAR γ) were expressed at different levels within BC cells. This fact coincides with RA sensitivity reported for BCcells, where T 47D and SK BR3 are considered RA sensitive and MDA MB 231 RA res istant based on their high and low expressionof RARs, respectively. Finally, RA treatment modulated EMT related proteins, E Cadherin , Vimentin , and m etalloproteases MMP2and MMP9 in both cell lines In conclusion , despite the absence of RAR receptors, RA affects and modulates mRNA and protein levelsin RA resistant cells and affects the expression of proteins involved in the migratory process in sensitive and resistant cells . T heseresults could be significant as a potential therapy for metastatic breast cancers without specific treatment.