Wang, Weiwei

Abstract Glioblastoma (GBM), the most aggressive primary brain tumor in adults, presents significant challenges due to its universal recurrence and limited survival rates, exacerbated when proximal to the lateral ventricles (LV). The subpopulation of brain tumor-initiating cells (BTICs) plays a pivotal role in tumor initiation and invasiveness, interacting with the microenvironment, particularly the cellular components in the subventricular zone (SVZ), like Neural Progenitor Cells (NPCs). Mechanisms of intercellular communication present in the SVZ include paracrine, autocrine, direct cell contact, and more recently extracellular vesicles (EVs). EVs are membrane-bound particles released by cells that are central to intercellular communication. They carry bioactive proteins, RNA, and other molecules that influence recipient cell behavior. This study investigates the role of EVs in GBM’s communication with non-cancer cells. Our findings indicate that BTIC-derived EVs promote migration and proliferation (*p < 0.02, ****p <0.001) in NPCs in vitro, highlighting the EVs’ role in altering the microenvironment. Additionally, we leverage a multi-omic approach to profile the small RNA and protein cargo of BTIC-EVs while also evaluating changes in the transcriptome of NPCs after BTIC-EV treatment. To identify the protein cargo contained in GBM-derived EVs, we utilized the innovative proximity-labeling system TurboID. We successfully induced TurboID expression in primary-cultured human BTICs from GBM patients, enabling the unbiased biotinylation of proteins in EVs. This method marks the first implementation of TurboID for unbiased global labeling of EV protein cargo in primary GBM cells. We identified unique miRNAs to be regulators of NPC’s transcriptome, and ontogenic analysis revealed upregulation of pathways involved in maintaining stem-like state, and upregulating PI3k-AKT, mTOR, and WNT signaling. This approach facilitates the investigation of EV-mediated communication and potential therapeutic targets, contributing to the understanding of GBM’s complex interactions with the brain’s microenvironment and the identification of biomarkers for improved diagnosis and treatment response.

Objective Primary sclerosing cholangitis (PSC) is a genetically complex, inflammatory bile duct disease of largely unknown aetiology often leading to liver transplantation or death. Little is known about the genetic contribution to the severity and progression of PSC. The aim of this study is to identify genetic variants associated with PSC disease progression and development of complications. Design We collected standardised PSC subphenotypes in a large cohort of 3402 patients with PSC. After quality control, we combined 130 422 single nucleotide polymorphisms of all patients—obtained using the Illumina immunochip—with their disease subphenotypes. Using logistic regression and Cox proportional hazards models, we identified genetic variants associated with binary and time-to-event PSC subphenotypes. Results We identified genetic variant rs853974 to be associated with liver transplant-free survival (p=6.07×10–9). Kaplan-Meier survival analysis showed a 50.9% (95% CI 41.5% to 59.5%) transplant-free survival for homozygous AA allele carriers of rs853974 compared with 72.8% (95% CI 69.6% to 75.7%) for GG carriers at 10 years after PSC diagnosis. For the candidate gene in the region, RSPO3, we demonstrated expression in key liver-resident effector cells, such as human and murine cholangiocytes and human hepatic stellate cells. Conclusion We present a large international PSC cohort, and report genetic loci associated with PSC disease progression. For liver transplant-free survival, we identified a genome-wide significant signal and demonstrated expression of the candidate gene RSPO3 in key liver-resident effector cells. This warrants further assessments of the role of this potential key PSC modifier gene.