Project description:This study aims to identify novel cancer stem cell markers by analyzing gastric cancer with spatial transcriptome. This analysis identified a cancer stem cell-associated molecule.
Project description:Genomic and epigenomic studies support that adenocarcinomas of the gallbladder develop according to a metaplasia-biliary intraepithelial neoplasia (BilIN)-adenocarcinoma histogenic sequence, in which metaplasia and BilIN are non-cancerous lesions of the epithelium. Moreover, recent genomic data suggest that adenocarcinoma can develop in a BilIN-dependent or -independent way, pointing toward patient-specific tumourigenic processes. Spatial transcriptomic data addressing these processes are still missing. Here, using GeoMx digital spatial profiling (NanoString), we characterized the spatial transcriptome of normal gallbladder epithelium, BilINs and adenocarcinoma coexisting within the same samples. To address intra-patient variability we profiled the whole transcriptome of a high number of regions of interest (ROIs) per sample in two patients (Patient #1, 81 year old woman: 24 ROIs; Patient #2, 53-year old man:32 ROIs), with each ROI covering approximately 200 cells of normal epithelium, low-grade BilIN, high-grade BilIN or adenocarcinoma. Our results showed that each type of lesion displayed little transcriptomic variability within the same patient, but differed significantly between patients. They also suggested that adenocarcinoma can derive from high-grade BilIN or from low-grade BilIN, with co-existing high-grade BilIN evolving via a distinct process in the latter case. We also provide strong evidence for patient-specific tumourigenic mechanisms, characterized by distinct sequences of signalling pathway activation. Among those pathways, we functionally investigated SEMAPHORIN 4A (SEMA4A) and provided evidence that repression of SEMA4A expression, as is observed in the gallbladder samples of the two patients, can enhance cell migration and survival, and perturb polarisation of the epithelial cells. In conclusion, our results support that gallbladder adenocarcinoma develops according to patient-specific processes that can be promoted by repression of SEMA4A. They underscore the need to gain gene expression data in addition to histological information to evaluate the risk of low-grade preneoplastic lesions.
Project description:Identification of the microRNA signature associated with human gastric adenocarcinoma. Total RNA obtained from 60 primary gastric cancer tissues and 8 surrounding non-cancer tissues was used for microarray analysis. For validation, real-time RT-PCR was performed.
Project description:We have now developed an organoid-based model of gastric cancer from GAstric Neoplasia (GAN) mice, which express Wnt1 and the enzymes COX2 and microsomal prostaglandin E synthase 1 in the stomach. Both p53 knockout (GAN-p53KO) organoids and KRASG12V-expressing GAN-p53KO (GAN-KP) organoids were generated by genetic manipulation of GAN mouse–derived tumor (GAN-WT) organoids. To uncover the molecular mechanism underlying the intratumoral heterogeneity of GAN-KP tumors, we performed spatial transcriptomics analysis with the 10× Genomics Visium platform, which allows characterization of the spatial topography of gene expression.
Project description:The ACP02 cell line was stablished from a primary diffuse adenocarcinoma (T3N2M0) and AGP01 cell was established from ascitic fluid cells from intestinal gastric adenocarcinoma (T3N2M1). mRNA samples from cell lines were amplified, labeled, and hybridized to the Affymetrix GeneChip Human Exon 1.0 ST array. The chip array data analysis was performed with Partek® software (http://www.partek.com).
Project description:To systematically elaborate the transcriptomic landscape and complicated mechanism of gastric adenocarcinoma, we performed whole-transcriptome sequencing to screen miRNA, lncRNA, circRNA and mRNA expression profiles and the key functional ncRNAs were annotated.