Project description:Cellular dormancy and heterogeneous cell cycle lengths provide important explanations for treatment failure following adjuvant therapy with S-phase cytotoxics in colorectal cancer (CRC) yet the molecular control of the dormant versus cycling state remains unknown. In CRCs dormant cells are found to be highly clonogenic and resistant to chemotherapies. We sought to understand the molecular features of dormant CRC cells to facilitate rationale identification of compounds to target both dormant and cycling tumour cells.
Project description:Spheroids, near spherical multicellular aggregates, are one of the most common types of threedimensional (3D) cell cultures. Despite decades of implementation of spheroid technology in various fields of life science and medical research, no minimal information (MI) guidelines are available to cope with heterogeneity and to stimulate transparency. To cope with this unmet need, we assembled an international consortium to develop the MISpheroID knowledgebase (https://www.mispheroid.org) and interrogation revealed heterogeneity and lack of transparency in published spheroid-related experiments. This steered us to empirically evaluate the impact of cell line, culture medium type, spheroid formation method and spheroid size on complementary spheroid metrics (RNA fingerprints, presence of cell death, ATP content, glucose to lactate conversion, secreted protein signatures, circularity, size and cancer therapy response). We measured media-induced transcriptional variation in lung cancer (A549), colorectal cancer (HCT116), ovarium cancer (SKOV3) and glioblastoma (U87MG) spheroids using RNA sequencing (RNA-seq). These spheroids were formed in ultra-low attachment plates and cultured in 6 different media types (DMEM high glucose, DMEM/F12, RPMI1640, DMEM low glucose, EMEM and MEM) for 5 (HCT116) or 7 (A549, SKOV3 and U87MG) days. RNA extraction was performed on 2 spheroids per condition using the miRNeasy micro kit (217084, Qiagen, Hilden, Germany). RNA-sequencing libraries were prepared from purified RNA using the QuantSeq 3' mRNA-Seq Library Prep Kit FWD for Illumina (Lexogen, Vienna, Austria) according to the manufacturer's instructions, using 27.5ng of RNA that was DNase treated using HL-dsDNA (Arcticzymes, TromsØ, Norway). The individual libraries were quantified by qPCR using the KAPA Library Quantification Kit (Roche, Pleasanton, CA, US) and equimolarly pooled. The pool concentration was measured with Qubit and 1.4pM with 1% PhiX was sequenced on a NextSeq 500 (Illumina, San Diego, CA, US) using a high-output 1x75 run. Reads were mapped to the human genome using Tophat and gene expression counts were generated using HTSeq. This data was used to perform Principal Component Analysis (PCA) and Gene Set Enrichment Analysis (GSEA).
Project description:Spheroids are 3D multi-cell aggregates formed in non-addherent culture conditions. In ovarian cancer (OC), they serve as a vehicle for cancer cell dissemination in the peritoneal cavity. We investigated genes and networks upregulated in three dimensional (3D) versus two-dimensional (2D) culture conditions by Affymetrix gene expression profiling and identified ALDH1A1, a cancer stem cell marker as being upregulated in OC spheroids. Network analysis confirmed ALDH1A1 upregulation in spheroids in direct connection with elements of the beta-catenin pathway. A parallel increase in the expression levels of beta-catenin and ALDH1A1 was demonstrated in spheroids vs. monolayers an in successive spheroid generations by using OC cell liness and primary OC cells. The percentage of Aldefluor positive cells was significantly higher in spheroids vs. monolayers in IGROV1, A2780, SKOV3, and primary OC cells. B-catenin knock-down decreased ALDH1A1 expression and chromatin immunoprecipitation demonstrated that beta-catenin directly binds to the ALDH1A1 promoter. Both siRNA mediated beta-catenin knock-down and a novel ALDH1A1 small molecule enzymatic inhibitor described here for the first time, decreased the number of OC spheroids (p<0.001) and cell viability. These data strongly support the role of beta-catenin regulated ALDH1A1 in the maintenance of OC spheroids and of a stem cell phenotype and propose new ALDH1A1 inhibitors targeting this cell population. Different gene profiles were observed in ovarian cancer spheroids versus ovarian cancer monolayers. Nine samples were analyzed in triplicate. Each group is a reference.
Project description:Chromatogram library generated of pooled sample. Coculture spheroids formed from fibroblast and colon cancer cell lines, and monoculture spheroids formed from the colon cancer cell line HCT116.
Project description:We deciphered specific traits of acidic cancer cells by comparing gene expression profiles in acidic (negative K-pHLIP and positive pHLIP cells) and buffered (negative pHLIP cells) cell compartments from HCT116 colorectal cancer 3D spheroids.
Project description:Cancer progression and wound healing share some characteristics. Most colorectal cancers are differentiated adenocarcinomas that maintain three-dimensional structures to some extent. Hence, disruption of the architecture can provoke remodeling similar to the remodeling of normal intestinal epithelium. We used our recently developed three-dimensional culture system to investigate the response of cancer cell spheroids to mechanical disruption. Specifically, we developed a protocol for homogenous disruption of the spheroids that maintained the cell-cell contacts. After disruption, 9 spheroids from 9 patient samples reformed within a few hours, and 2 showed accelerated spheroid growth. Stemness increased after spheroid disruption, as assessed by marker expression, spheroid forming capacity, radiation sensitivity, and tumorigenesis. The spheroid-forming capacity increased in 6 of 11 spheroids. The disruption signature, as determined by gene expression profiling, supported the incidence of remodeling and predicted the prognosis of the colorectal cancer patients. WNT and HER3 signaling was increased in the reformed spheroids, and suppression of these signaling pathways attenuated the increases in growth and stemness after disruption. Thus, disorganized architecture in patient tumors might reflect the processes of disruption and subsequent remodeling and represent a cause rather than simply a consequence of malignancy progression. Gene expression in cancer tissue-originated spheroids (CTOSs) was measured at pre, 6 hr, 24 hr, and 4 days after mechanical disruption. One experiment was performed at each time point.