Expression profile of individual Pregnancy-Specific Glycoprotein genes during syncytialization of human trophoblast cells

CAMOLOTTO, S.; NORES, R.; PATRITO, L.; PANZETTA-DUTARI, G.

Pinamar

Congreso; XLI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2005

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Pregnancy-specific glycoproteins (PSG) are encoded by 11 highly similar genes tightly linked within a 700-kb region in Ch 19q13.2. PSGs are essential for gestation in mammalian species and their expression is markedly induced during trophoblast cells differentiation. However, the transcriptional induction and mRNA level of each PSG members are unknown. This report examines PSGs expression profile during in vitro syncytialization, as well as the contribution of the proximal promoter sequence in their transcription. Placental cytotrophoblast and choriocarcinoma Jeg3 cell line were induced to differentiate into syncytium. RNA was isolated from both cell types at different times and analyzed by semi-quantitative RT-PCR using PSG 1, 3, 5 and 7 gene specific primers. A differential expression pattern for each gene was found in both models. Luciferase reporter vectors bearing 600 pb of the promoter region of each gene, transiently transfected in Jeg3 cells, displayed promoter activities which were in agreement with endogenous transcripts levels. Multiple sequence alignments of the 600 pb and up to 3000 pb 5´ upstream the ATG codon revealed pairwise alignment identities of 92-94%. No significant correlation was found between previously characterized sequence motifs and transcription of individual PSG genes. The present study indicates a different expression profile of PSGs, suggesting a complex transcriptional regulation and a specific importance of each member in trophoblast differentiation. Supported by CONICET, FONCyT and SECyT-UNC.