Project description:Gastric cancer (GC) is a challenging malignant disease among gastrointestinal tumors. The clinical treatments for GC include surgery, neoadjuvant therapy and adjuvant chemotherapy. As patients’ response to chemotherapeutic drugs varies, an approach to predict the efficacy of chemotherapeutic treatment is urgently needed. Here, a biorepository of 17 human gastric tumor organoids (GTOs) and 9 normal organoids (GNOs) derived from GC patients was established, which contains the intestinal, diffuse and mixed-type of GC. GTOs retained morphologic, histopathological and genetic features of the tumors from which they were derived, and patient-derived organoid xenograft model indicated tumorigenicity of organoids. GTOs responses to clinically respective chemotherapy treatment positively correlated with the individual patient’s clinical response. Meanwhile, GNOs, which maintained original characteristics of corresponding tissues, could be separated from GTOs. The use of GNOs predicted the cytotoxic effect of chemotherapy on the organism. Our study implies that patient-derived organoids predict GC patient responses to chemotherapy and provide a solution for personalized treatment.
Project description:To understand the molecular basis of the acquisition of 5-FU resistance in gastric cancer stem cells, we established 5-FU-resistant gastric cancer organoids. We used microarrays to detail the global program of gene expression underlying 5-FU resistance and maintenance of stem cell properties in gastric cancer.
Project description:We treated mouse gastric organoids with Helicobacter pylori, Fusobacterium nucleatum, and Neisseria subflava, and extracted RNA after 4 hours. RNAs were applied to RNA sequencing analysis to investigate bacteria-specific effects on gastric epithelial cells.
Project description:Human embryonic stem cells (WA01) were differentiated in a step-wise manner into three-dimensional human gastric organoids (hGOs). At day 34 of differentiation, the hGOs were collected and analyzed by RNA-sequencing.
Project description:As metabolic rewiring is crucial for cancer cell proliferation, metabolic phenotyping of patient-derived organoids is desirable to identify drug-induced changes and trace metabolic vulnerabilities of tumor subtypes. We established a novel protocol for metabolomic and lipidomic profiling of colorectal cancer organoids by LC-QTOF-MS facing the challenge of capturing metabolic information from minimal sample amount (< 500 cells/injection) in the presence of extracellular matrix (ECM). The best procedure of the tested protocols included ultrasonic metabolite extraction with acetonitrile/methanol/water (2:2:1, v/v/v) without ECM removal. To eliminate ECM-derived background signals, we implemented a data filtering procedure based on p-value and fold change cut-offs which retained features with signal intensities >120% compared to matrix-derived signals present in blank samples. As a proof-of-concept, the method was applied to examine the early metabolic response of colorectal cancer organoids to 5-fluorouracil treatment. Statistical analysis revealed dose-dependent changes in the metabolic profiles of treated organoids including elevated levels of 2'-deoxyuridine, 2'-O-methylcytidin, inosine and 1-methyladenosine and depletion of 2'-deoxyadenosine and specific phospholipids. In accordance with the mechanism of action of 5-fluorouracil, changed metabolites are mainly involved in purine and pyrimidine metabolism. The novel protocol provides a first basis for the assessment of metabolic drug response phenotypes in 3D organoid models.
Project description:Gastric cancer ranks the fifth most common malignancy and the third leading cause of cancer related death worldwide. Classical chemotherapy is still the standard treatment in advanced stages, with only two targeted therapies currently in clinical use. Several targeted trials have failed, likely due to missing relevant biomarkers that predict response. Patient derived cancer organoids (PDOs) constitute a three dimensional cell culture system showing self renewal, self organization and regularly unlimited proliferation while faithfully recapitulating many aspects of the tumor they are derived from. Nevertheless, the complex individual mutational landscape hampers the use of PDOs for basic and translational research. We therefore characterized three murine tumor organoid models with defined mutational patterns altering specific oncogenic pathways: a RAS activated (KrasG12D, Tp53R172H), a WNT activated (Apcfl/fl, Tp53R172H) and a diffuse (Cdh1fl/fl, Apcfl/fl) tumor model. The models were analyzed phenotypically, a proteome signature was established and a drug screen performed. The models were morphologically diverse, were characterized by individual protein expression signatures and showed differential drug sensitivities. The developed organoid models allow functional assays as well as pathway specific drug interference testing in a genetically defined setting.
Project description:Tumors consist of heterogeneous cell population, containing cancer cell subpopulations with anticancer drug-resistant property, called “persister” cells. To reveal the character of the persister cells, we analyzed gene expression profile of patient-derived gastric cells and residual cancer cells after treatment with 5-FU or SN38, an active metabolite of irinotecan. In our study, we identified ALDH1A3 as a marker and a cell proliferation factor of persister cells. To examine molecular pathways regulated by ALDH1A3, we analyzed gene expression profile of patient-derived gastric JSC15-3 in which ALDH1A3 was knocked down by using shRNAs.