Biology subjects

Raggi, C.

Publications and source records attributed to Raggi, C..

5 recordsLinked to original sources

bioRxiv2026

Endogenous PROM1 activation redistributes liver cancer cells along a preexisting differentiation axis

CD133 is widely used as a marker of stem-like cells in hepatocellular carcinoma, yet its functional contribution remains incompletely defined. In PLC/PRF/5 cells, acute CRISPR activation of endogenous PROM1 suppresses hepatic programs, whereas PROM1 knockdown elicits an opposing hepatocyte-identity response, together defining a PROM1-responsive transcriptional axis. Single-cell profiling shows that this axis is preexisting and tracks endogenous PROM1 heterogeneity, separating a hepatocyte-like, PROM1-low compartment from a PROM1-enriched, less hepatocyte-like compartment. Sustained PROM1 activation reduces the hepatocyte-like compartment and shifts the population toward intermediate positions along this axis. Related transcriptional patterns are detectable in an independent HuH-7 dataset and a human HCC case. Endogenous ALFA tagging identifies candidate CD133-associated proteins. Together, these findings support CD133 as an active contributor to tumor-cell state redistribution, extending its role beyond a mere marker of stem-like populations.

cancer biology↗

bioRxiv2025

Off-the-Shelf Engineered Liver Tissue Reverses Acute Liver Failure Without Immunosuppression

There is an urgent need for effective solutions to replace liver functions in patients with acute liver failure (ALF). We describe here a human engineered liver tissue composed of induced pluripotent stem cell (iPSC)-derived liver organoids encapsulated within a non-degradable biomaterial. Unlike most stem cell-derived products, this encapsulated liver tissue (ELT) achieves functional maturation during manufacturing. When transiently implanted into the peritoneal cavity of immunocompetent mice with ALF, the human ELT improves survival, treats hepatic encephalopathy and promotes liver regeneration, without requiring immunosuppression. Based on robust processes and designed to overcome challenges such as foreign body reaction, loss of function and cryopreservation, the ELT does not require vascularization and provides immediate and long-lasting functional replacement. Once the liver regenerated, the ELT is explanted, leaving the subjects cured. Macroencapsulation prevents rejection by shielding the organoids from the host immune system, and minimizes the risk of tumorigenicity. The data shown demonstrate the ELTs potential to be developed into a safe and effective off-the-shelf treatment that, if validated in upcoming clinical trials, could replace liver transplantation for many patients with ALF.

bioengineering↗

bioRxiv2025

NTBC dosing and outcomes in hereditary tyrosinemia type 1: insights from a representative human model and 99 patients

Hereditary tyrosinemia type 1 (HT1) is a rare and severe metabolic liver disorder caused by fumarylacetoacetate hydrolase (FAH) deficiency. The optimal dose and long-term effects of the only available treatment, nitisinone (NTBC), remain unclear due to the absence of clinical trial data. Here, we generated a representative human in vitro model of HT1 using iPSC-derived hepatocytes, which faithfully recapitulated key disease features. We investigated the mechanisms of FAH deficiency-induced hepatocellular injury and evaluated the effects of NTBC treatment. We confirmed treatment efficacy and identified 50 {micro}mol/L as the minimal effective NTBC concentration to prevent cellular damage. This protective dose was subsequently validated in a large cohort of 99 HT1 patients, providing compelling evidence for establishing minimal therapeutic NTBC levels. Notably, approximately 10% of disease-associated genes, many implicated in hepatocellular carcinoma, remained dysregulated despite treatment, raising concerns that NTBC may not fully eliminate long-term oncogenic risk.

genetics↗

bioRxiv2021

Autologous humanized mouse models of iPSC-derived tumors allow for the evaluation and modulation of cancer-immune cell interactions

Modeling the tumor-immune cell interactions in humanized mice is complex and limits drug development. Here, we generated easily accessible tumor models by transforming either primary skin fibroblasts or iPSC-derived cell lines injected in immune-deficient mice reconstituted with human autologous immune cells. Our results showed that either fibroblastic, hepatic or neural tumors were all efficiently infiltrated and partially or totally rejected by autologous immune cells in humanized mice. Characterization of tumor immune infiltrates revealed high expression levels of the dysfunction markers Tim3 and PD-1 in T cells and an enrichment in regulatory T cell suggesting rapid establishment of an immunosuppressive microenvironment. Inhibition of PD-1 by Nivolumab in humanized mice resulted in an increased immune cell infiltration and a slight decrease in tumor growth. We expect these versatile and accessible cancer models will facilitate preclinical studies and the evaluation of autologous cancer immunotherapies across a range of different tumor cell types. SIGNIFICANCE STATEMENTPreclinical models capable of providing an environment where human tumors are confronted with autologous immune cells are not easily accessible and limit drug development. As an alternative we generated genetically-defined tumor cell lines from primary and iPSC-derived cells for the evaluation of cancer-immune cell interactions in autologous humanized mice.

cancer biology↗

bioRxiv2020

Leveraging complex interactions between signaling pathways involved in liver development to robustly improve the maturity and yield of pluripotent stem cell-derived hepatocytes

Pluripotent stem cell (PSC)-derived hepatocyte-like cells (HLC) have shown great potential as an alternative to primary human hepatocytes (PHH) for in vitro modeling. Several differentiation protocols have been described to direct PSC towards the hepatic fate, although the resulting HLC have shown more a fetal than adult phenotype. Here, by leveraging recent knowledge of the signaling pathways involved in liver development, we describe a robust, scalable protocol that allows to consistently generate high-quality HLC from both ESC and iPSC. Such HLC are comparable to adult PHH in terms of key mature liver functions and proved suitable to assess drug hepatotoxicity, as a proof of concept of their potential as a physiologically representative alternative for in vitro modeling.

developmental biology↗