Biology subjects

Weller, T. C.

Publications and source records attributed to Weller, T. C..

2 recordsLinked to original sources

bioRxiv2020

The unfolded protein response links tumor aneuploidy to local immune dysregulation

Aneuploidy is a chromosomal abnormality associated with poor prognosis in many cancer types. Here we tested the hypothesis that the unfolded protein response (UPR) links mechanistically aneuploidy and local immune dysregulation. Using a single somatic copy-number alteration (SCNA) score inclusive of whole-chromosome, arm and focal chromosome alterations in a pan-cancer analysis of 9,375 samples in The Cancer Genome Atlas (TCGA) database, we found an inverse correlation with a cytotoxicity (CYT) score across disease stages. Co-expression patterns of UPR genes changed substantially between SCNAlow and SCNAhigh groups. Pathway activity scores showed increased activity by multiple branches of the UPR in response to aneuploidy. The PERK branch showed the strongest association with a reduced CYT score. The conditioned medium of aneuploid cells transmitted XBP1 splicing and caused IL-6 and Arginase1 transcription in receiver bone marrow-derived macrophages. We propose the UPR as a mechanistic link between aneuploidy and immune dysregulation in the tumor microenvironment. Statement of SignificanceAneuploidy accumulates over the life of a tumor and is associated with poor prognosis. Tumor progression is also associated with a progressive immune dysregulation. To explain these complex and concurrent disorders we tested the hypothesis that the unfolded protein could represent the link between aneuploidy and a dysregulation of local immunity favoring tumor progression.

cancer biology↗

bioRxiv2020

IRE1? regulates macrophage polarization, PD-L1 expression and tumor survival

In the tumor microenvironment local immune dysregulation is driven in part by macrophages and dendritic cells that are polarized to a mixed proinflammatory/immune suppressive phenotype. The unfolded protein response (UPR) is emerging as the possible origin of these events. Here we report that the inositol-requiring enzyme 1 (IRE1) branch of the UPR is directly involved in the polarization of macrophages in vitro and in vivo, including the upregulation of IL-6, IL-23, Arginase1, as well as surface expression of CD86 and PD-L1. Macrophages in which the IRE1/Xbp1 axis is blocked pharmacologically or deleted genetically have significantly reduced polarization, and CD86 and PD-L1 expression, which was induced independent of IFN{gamma} signaling suggesting a novel mechanism in PD-L1 regulation in macrophages. Mice with IRE1- but not Xbp1-deficient macrophages showed greater survival than controls when implanted with B16.F10 melanoma cells. Remarkably, we found a significant association between the IRE1 gene signature and CD274 gene expression in tumor-infiltrating macrophages in humans. RNASeq analysis showed that bone marrow derived macrophages with IRE1 deletion lose the integrity of the gene connectivity characteristic of regulated IRE1-dependent decay (RIDD) and the ability to activate CD274 gene expression. Thus, the IRE1/Xbp1 axis drives the polarization of macrophages in the tumor microenvironment initiating a complex immune dysregulation leading to failure of local immune surveillance.

cancer biology↗