Project description:Gastric cancer peritoneal metastasis (GCPM) is a distinct clinical entity with a poor prognosis, characterized by aggressive features and limited treatment options. Understanding its molecular biology is critical for developing effective therapies. We performed whole genome and transcriptome sequencing on GCPM samples and paired primary gastric cancer (GC) tissues from 14 and 26 patients, respectively. Our analysis revealed substantial intra-patient heterogeneity between GCPM and primary tumors at both genetic and functional levels. Inter-patient variability was observed in mutational overlaps, with some signatures unique to either GCPM or primary tumors. Tumor evolution analysis suggested divergent clonal evolution, with distinct clones specific to GCPM or primary tumors in most patients. The tumor microenvironment (TME) was poorly conserved between primary GC and GCPM, with desert-type primary tumors often transitioning to immune-enriched TMEs in metastases. These findings suggest that immunotherapy resistance in GCPM may arise from factors beyond intrinsic TME characteristics, such as limited drug delivery due to the peritoneal-plasma barrier. Collectively, our results highlight significant molecular and TME heterogeneity between GCPM and primary tumors, emphasizing the need for GCPM-specific stratification and innovative treatment strategies to improve outcomes.
Project description:Triple-Negative Breast Cancer (TNBC) has a poor prognosis and adverse clinical outcomes among all breast cancer subtypes as there is no available targeted therapy. Overexpression of Enhancer of zeste homolog 2 (EZH2) has been shown to correlate with TNBC's poor prognosis, but the contribution of EZH2 catalytic (H3K27me3) versus non-catalytic EZH2 (NC-EZH2) function in TNBC progression remains elusive. We reveal that selective hyper-activation of functional EZH2 (H3K27me3) over NC-EZH2 alters TNBC metastatic landscape and fosters its peritoneal metastasis, particularly splenic. Instead of H3K27me3-mediated repression of gene expression; here, it promotes KRT14 transcription by attenuating binding of repressor Sp1 to its promoter. Further, KRT14 loss significantly reduces TNBC migration, invasion, and peritoneal metastasis. Consistently, human TNBC metastasis displays positive correlation between H3K27me3 and KRT14 levels. Finally, EZH2 knockdown or H3K27me3 inhibition by EPZ6438 reduces TNBC peritoneal metastasis. Altogether, our preclinical findings suggest a rationale for targeting TNBC with EZH2 inhibitors.
Project description:Pancreatic ductal adenocarcinoma (PDAC) frequently metastasizes into the peritoneum, which contributes to poor prognosis. Metastatic spreading is promoted by cancer cell plasticity, yet its regulation by the microenvironment is incompletely understood. Here, we show that the presence of hyaluronan and proteoglycan link protein-1 (HAPLN1) in the extracellular matrix enhances tumor cell plasticity and PDAC metastasis. Bioinformatic analysis showed that HAPLN1 expression is enriched in the basal PDAC subtype and associated with worse overall patient survival. In a mouse model for peritoneal carcinomatosis, HAPLN1-induced immunomodulation favored a more permissive microenvironment, which accelerated the peritoneal spread of tumor cells. Mechanistically, HAPLN1, via upregulation of tumor necrosis factor receptor 2 (TNFR2), promoted TNF-mediated upregulation of Hyaluronan (HA) production, facilitating EMT, stemness, invasion and immunomodulation. Extracellular HAPLN1 modified cancer cells and fibroblasts, rendering them more immunomodulatory. As such, we identified HAPLN1 as a prognostic marker and as a driver for peritoneal metastasis in PDAC.
Project description:10X Next GEM Single Cell 5’ Kit v2 scRNAseq of maximum 15 000 sorted CD127+ ILCs (CD45+, CD3-, CD19-, Lin- and CD127+), NK cells (CD45+, CD3-, CD19-, Lin-, CD94+/- and CD56+) and non-conventional (nc)ILCs (CD45+, CD3-, CD19-, Lin-, CD94+/-, CD56- and CD7+) per sample from 11 patients. Total of 4 paired healthy colon and colorectal cancer tumours, 2 paired healthy colon, colorectal cancer tumours and peritoneal metastasis and 5 unpaired peritoneal metastasis.
Project description:Peritoneal carcinomatosis is a common yet deadly manifestation of gastrointestinal cancers, with few effective treatments. To identify targetable determinants of peritoneal metastasis, we focused on appendiceal adenocarcinoma (AC), a gastrointestinal cancer that metastasizes almost exclusively to the peritoneum. Current treatments are extrapolated from colorectal cancer (CRC), yet AC has distinct genomic alterations, mucinous morphology and peritoneum restricted metastatic pattern. Further, no stable preclinical models of AC exist, limiting drug discovery and representing an unmet clinical need. We establish a first-in-class stable biobank of 16 long-term cultured AC patient-derived organoids (PDOs), including 3 matched primary AC-peritoneal carcinomatosis (AC-PC) pairs. By enriching for cancer cells, AC PDOs enable accurate genomic characterization relative to paucicellular AC tissue. We establish an organoid orthotopic intraperitoneal xenograft model that recapitulates diffuse peritoneal carcinomatosis and show that PC-organoids retain increased metastatic capacity, decreased growth factor dependency and sensitivity to standard of care chemotherapy relative to matched primary AC organoids. Single cell profiling of AC-PC pairs reveals dedifferentiation from mucinous differentiated states in primary AC into intestinal stem cell and fetal progenitor states in PC, with upregulation of oncogenic signaling pathways. Through hypothesis-driven drug testing, we identify RAS inhibitor RMC-7977 and Wnt-targeting tyrosine kinase inhibitor WNTinib as novel, clinically actionable strategies to more effectively target AC-PC.
Project description:Paired primary-metastasis patient-derived organoids and mouse models identify phenotypic evolution and druggable dependencies of peritoneal metastasis from appendiceal cancer