Project description:Acquired drug resistance is a major challenge for cancer therapy and the leading cause of cancer mortality. However, the mechanisms of drug resistance are diverse and the strategy to specifically target drug resistant cancer cells remains an unmet clinical issue. We establisheda32 colorectal cancer (CRC) PDO biobank and induced acquired drug resistance by repeated low-level exposures of chemo-agents. Chemosensitivity profiling and transcriptomic analysis studies34 revealed that chemo-resistant PDOs exhibited elevated expression of LGR4 and activationof the35 Wnt signaling pathway. Further, we performed antibody screening against LGR4 and selecteda36 monoclonal antibody (LGR4-mAb) that potently inhibited the LGR4/Wnt signaling. In drug resistant PDOs and xenograft models, treatment with LGR4-mAb significantly sensitizeddrug- 38 induced ferroptosis. Mechanistically, LGR4 dependent Wnt signaling transcriptionally up-regulated SLC7A11, a key inhibitor of ferroptosis, to confer acquired drug resistance. Targeting40 Wnt signaling by LGR4-mAb and by other modulators augments ferroptosis when co-administrated with chemotherapeutic agents. Finally, LGR4-mAb therapy was effective against other cancers that express high levels of LGR4. Collectively, our results demonstrate a new strategy to selectively activate ferroptosis and provide a new opportunity to fight refractoryand44 recurrent cancers.
Project description:Transcriptomic profiles of 6 commercially-available human patient-derived gastrointestinal organoid lines were obtained and compared to transcriptomic profile of a commercially available human iPSC-induced colon organoid line. Transcriptomic profile of iPSC-derived human colon organoid line was compared after culture in either Corning growth-factor-reduced Matrigel (Corning 356231) or MilliporeSigma growth-factor-reduced ECMGel (E6909)
Project description:Six non- and drug-resistant colorectal cancer cell lines were selected in this study, which were non-resistant cell lines: HCT116 and LoVo, four drug-resistant cell lines: HCT116-OxPt, HCT116-SN38, LoVo-OxPt, LoVo-SN38.Proteins extraced from three HCT116 related cell lines were labled and pooled together, and proteins from other three LoVo related cell lines were labled and pooled together.
Project description:Colon cancer cell lines with partial sensitivity to the BRAF inhibitor PLX4720 were grown in increasing concentration of the drug to develop acquired resistance. Gene expression was performed for comparison of the resistant clones to the parental lines. Colon cancer cell lines with partial sensitivity to the BRAF inhibitor PLX4720 were grown in increasing concentration of the drug to develop acquired resistance. Gene expression was performed for comparison of the resistant clones to the parental lines.
Project description:Transcriptomic changes in human liver cancer cell lines caused by the demethylating drug zebularine. Epigenomic changes such as aberrant hypermethylation and subsequent atypical gene silencing are characteristic features of human cancer. Here, we report a comprehensive characterization of epigenomic modulation caused by zebularine, an effective DNA methylation inhibitor, in human liver cancer. Using transcriptomic and epigenomic profiling, we identified a zebularine signature that classified liver cancer cell lines into two major subtypes with different drug-responses. In drug-sensitive cell lines, zebularine caused inhibition of proliferation coupled with increased apoptosis, whereas drug-resistant cell lines were associated with upregulation of oncogenic networks (e.g. E2F1, MYC, and TNF) driving liver cancer growth in vitro and in mice. Assessment of zebularine-based therapy in xenograft mouse models demonstrated potent therapeutic effects against tumors established from zebularine-sensitive but not zebularine-resistant liver cancer cells leading to increased survival and decreased pulmonary metastasis. Integration of zebularine gene expression and demethylation response signatures differentiated patients with HCC according to their survival and disease recurrence and identified a subclass of patients within the poor survivors likely to benefit from therapeutic agents that target the cancer epigenome. Each cell line was mock treated or treated with 100uM and 200uM zebularine for 7 days, respectively *** This Series represents the gene expression component of the study.
Project description:In Rspondin-based 3D cultures, Lgr5 stem cells from multiple organs form ever-expanding epithelial organoids that retain their tissue identity. We report the establishment of tumor organoid cultures from 20 consecutive colorectal (CRC) patients. For most, organoids were also generated from adjacent normal tissue. The organoids closely resemble the original tumor. The spectrum of genetic changes observed within the 'living biobank' agrees well with previous large-scale mutational analyses of CRC. Gene expression analysis indicates that the major CRC molecular subtypes are represented. Tumor organoids are amenable to robotized, high-throughput drug screens allowing detection of gene-drug associations. As an example, a single organoid culture was exquisitely sensitive to Wnt secretion (porcupine) inhibitors and carried a mutation in the negative Wnt feedback regulator RNF43 (rather than in APC). Organoid technology may fill the gap between cancer genetics and patient trials, complement cell line- and xenograft-based drug studies and allow personalized therapy design. We generated organoids from healthy tissue and coloncarcinoma tissue. The organoids were trypsinized, plated in matrigel and overlaid with medium. After three days, RNA was isolated using Qiagen RNAeasy. Medium conditions are the same for all organoids, irrespective of their origin.
Project description:Given that colorectal cancer stem cells (CCSCs) play key roles in the tumor dormancy, metastasis and relapse, targeting CCSCs is a promising strategy in cancer therapy. Here, we aimed to identify new regulators of CCSCs and found that Cullin 4B (CUL4B), which possesses oncogenic properties in multiple solid tumors, drives the development and metastasis of colon cancer by sustaining cancer stem-like features. Elevated expression of CUL4B was confirmed in colon tumors and was associated with poor overall survival. Inhibition of CUL4B in cancer cell lines and patient-derived tumor organoids led to reduced sphere formation, proliferation and metastasis capacity. Mechanistically, CUL4B coordinates with PRC2 complex to repress miR34a expression, thus up-regulates oncogenes including MYCN and NOTCH1, which are targeted by miR34a. Mutation of miR34a binding sites in the 3'UTR of the oncogenes rescues the phenotype caused by CUL4B depletion. Significant correlations were found between expression of CUL4B and miR34a (negatively), miR34a target genes (positively) in clinical samples from colon cancer patients. Collectively, our work demonstrates that CUL4B functions to repress miR34a in maintaining cancer stemness in CRC and provides a potential therapeutic target.
Project description:Colon cancer cell lines with partial sensitivity to the BRAF inhibitor PLX4720 were grown in increasing concentration of the drug to develop acquired resistance. Gene expression was performed for comparison of the resistant clones to the parental lines.
Project description:In Rspondin-based three-dimensional cultures, Lgr5 stem cells from multiple organs form ever-expanding epithelial organoids that retain their tissue identity. Here we report the establishment of tumor organoid cultures from 20 consecutive colorectal carcinoma (CRC) patients. For most, organoids were also generated from adjacent normal tissue. Organoids closely resemble the original tumor. The spectrum of genetic changes within the 'living biobank' agrees well with previous large-scale mutational analyses of CRC. Gene expression analysis indicates that the major CRC molecular subtypes are represented. Tumor organoids are amenable to high-throughput drug screens allowing detection of gene-drug associations. As an example, a single organoid culture was exquisitely sensitive to Wnt secretion (porcupine) inhibitors and carried a mutation in the negative Wnt feedback regulator RNF43, rather than in APC. Organoid technology may fill the gap between cancer genetics and patient trials, complement cell line- and xenograft-based drug studies and allow personalized therapy design. Self-renewal of the intestinal epithelium is driven by Lgr5 stem cells located in crypts. We have recently developed a long-term culture system that maintains basic crypt physiology. Wnt signals are required for the maintenance of active crypt stem cells. Indeed, the Wnt agonist R-spondin1 induces dramatic crypt hyperplasia in vivo. R-spondin-1 is the ligand for Lgr5. Epidermal growth factor (EGF) signaling is associated with intestinal proliferation, while transgenic expression of Noggin induces a dramatic increase in crypt numbers. The combination of R-spondin-1, EGF, and Noggin in Matrigel sustains ever-expanding small intestinal organoids, which display all hallmarks of the original tissue in terms of architecture, cell type composition, and self-renewal dynamics. We adapted the culture condition for long-term expansion of human colonic epithelium and primary colonic adenocarcinoma, by adding nicotinamide, A83-01 (Alk inhibitor), Prostaglandin E2 and the p38 inhibitor SB202190. Of note, a two-dimensional culture method for cells from normal and malignant primary tissue has been described by Schlegel and colleagues. Here, we explore organoid technology to routinely establish and phenotypically annotate ‘paired organoids’ derived from adjacent tumor and healthy epithelium from CRC patients.