Biology subjects

Coso, O.

Publications and source records attributed to Coso, O..

3 recordsLinked to original sources

bioRxiv2023

Tristetraprolin promotes survival of mammary progenitor cells by restraining TNFα levels

Tristetraprolin (TTP) is a RNA binding protein that destabilizes mRNA of factors that up-regulate proliferation, invasiveness and inflammation. Here we show that TTP expression is higher in mammary progenitor cells than in other cell populations, and that reducing its levels impairs mammary gland morphogenesis in vivo and mammosphere formation in culture. Knocking down TTP in stem-like HC11 mouse mammary cell line increased inflammatory cytokine mRNAs and signaling cascades involving NF{kappa}B, STAT3 and MAPK p38 activation, which led to apoptosis. Importantly, TNF overexpression and the consequent p38 phosphorylation would be the leading cause of progenitor cell death upon TTP expression restriction. Taken together, our results reveal the relevance of negative posttranscriptional regulation on TNF, exerted by TTP, for the maintenance of the progenitor cell compartment in the mammary gland.

developmental biology↗

bioRxiv2021

A non-coding RNA network involved in KSHV tumorigenesis

Regulatory pathways involving non-coding RNAs (ncRNAs) such as microRNAs (miRNAs) and long non-coding RNAs (lncRNA) have gained great relevance due to their role in the control of gene expression modulation. Using RNA sequencing of KSHV Bac36 transfected mouse endothelial cells (mECK36) and tumors, we have analyzed the host and viral transcriptome to uncover the role lncRNA-miRNA-mRNA driven networks in KSHV tumorigenesis. The integration of the differentially expressed ncRNAs, with an exhaustive computational analysis of their experimentally supported targets, led us to dissect complex networks integrated by the cancer-related lncRNAs Malat, Neat1, H19, Meg3 and their associated miRNA-target pairs. These networks would modulate pathways related to KSHV pathogenesis, such as viral carcinogenesis, p53 signaling, RNA surveillance, and Cell cycle control. Finally, the ncRNA-mRNA analysis allowed us to develop signatures that can be used to an appropriate identification of druggable gene or networks defining relevant AIDS-KS therapeutic targets.

cancer biology↗

bioRxiv2019

A major Role for Nrf2 transcription factors in cell transformation by KSHV encoded oncogenes.

Kaposi s sarcoma (KS) is the most common tumor in AIDS patients and the highly vascularized patient s skin lesions are composed of the cells that derive from the endothelial tissue transformed by the KSHV virus. Heme oxygenase-1 (HO-1) is an enzyme upregulated by the Kaposi s sarcoma-associated herpesvirus (KSHV) and highly expressed in human Kaposi Sarcoma (KS) lesions. The oncogenic G protein-coupled receptor (KSHV-GPCR or vGPCR) is expressed by the viral genome in infected cells and is involved in KS development, HO-1 expression and vascular endothelial growth factor (VEGF) expression. We have characterized that vGPCR induces HO-1 expression and HO-1 dependent transformation through the Ga13 subunit of heterotrimeric G proteins and the small GTPase RhoA. We have found here several lines of evidence that support a role for Nrf2 transcription factors and family members in the vGPCR,-Ga13,-RhoA signaling pathway that converges on the HO-1 gene promoter. Our current information assigns a major role to Erk1/2 MAPK pathways as intermediate in signaling from vGPCR to Nrf2, influencing Nrf2 translocation to the cell nucleus, Nrf2 transactivation activity and consequently HO-1 expression. Experiments in nude mice show that the tumorigenic effect of vGPCR is dependent on Nrf2 suggesting this transcription factor or its associated proteins as putative pharmacological or therapeutic targets in KS.

cancer biology↗