Luciferase Expressing Preclinical Model Systems Representing the Different Molecular Subtypes of Colorectal Cancer
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ABSTRACT: We established combined 2D/3D, in vitro/in vivo model systems representing the heterogeneity of colorectal cancer (CRC) with regards to different molecular subtypes. Comparative characterization of stable luciferase expressing derivatives of well-established CRC cell lines, derived spheroids and subcutaneous xenograft tumors showed that the 3D-spheroid cultures resembled xenografts more closely than 2D-cultured cells do. The model systems can be used in preclinical research applications to study new therapy approaches and represents the biological heterogeneity of CRC.
Project description:Cancer tissue-like structures were developed by using established human tumor cell lines in perfusion-based bioreactor systems. In colorectal cancer (CRC) cell lines, perfusion allowed more homogeneous scaffold seeding than tri-dimensional (3D) static cultures and significantly (13.7 fold, p<0.0001) higher proliferation. Resulting tissues exhibited morphology and phenotypes similar to xenografts generated in immunodeficient mice. Whole transcriptome analysis of 2D, 3D static and 3D perfusion cultures revealed the highest correlation between xenografts and 3D perfusion cultures (r=0.985). Clinically relevant concentrations of 5-FU, used in neo- and adjuvant CRC treatment, had no effect on numbers of HT-29 CRC cells cultured in 3D perfusion or xenografts, as compared with a 55.8% reduction in 2D cultures. Treatment induced apoptosis in 2D cultures, but only “nucleolar stress” in perfused cells and xenografts, consistent with partial responsiveness. In 3D perfusion cultures BCL-2, TRAF1, and FLIP gene expression was marginally affected, as compared with significant down-regulation in 2D cell cultures. Accordingly, ABT-199 BCL-2 inhibitor, induced cytostatic effects in 3D perfusion but not in 2D cell cultures (p=0.003). Tumor cells from partially responsive (Dworak 2) patients undergoing neo-adjuvant treatment, typically (10/11) expressed BCL-2, as compared with 0/3 highly (Dworak 3-4) responsive and 4/15 fully resistant CRC (Dworak 0/1, p=0.03), closely matching 3D perfusion cultures data. These results indicate that 3D perfusion cultures efficiently mimic phenotypic and functional features observed in xenografts and clinical specimens. These models may be of critical translational relevance to address fundamental human tumor cell biology issues and to develop predictive pre-clinical tests of novel compounds.
Project description:Colorectal cancer (CRC) is a heterogeneous disease. More insight into the biological diversity of CRC is needed to improve therapeutic outcomes. Established CRC cell lines are frequently used and were shown to be representative models of the main subtypes of CRC at the genomic and transcriptomic level. In the present work, we established stable, luciferase expressing derivatives from 10 well-established CRC cell lines, generated spheroids and subcutaneous xenograft tumors in nude mice, and performed comparative characterization of these model systems. Transcriptomic analyses revealed the close relation of cell lines with their derived spheroids and xenograft tumors. The preclinical model systems clustered with patient tumor samples when compared to normal tissue thereby confirming that cell-line-based tumor models retain specific characteristics of primary tumors. Xenografts showed different differentiation patterns and bioluminescence imaging revealed metastatic spread to the lungs. In addition, the models were classified according to the CMS classification system, with further sub-classification according to the recently identified two intrinsic epithelial tumor cell states of CRC, iCMS2 and iCMS3. The combined data showed that regarding primary tumor characteristics, 3D-spheroid cultures resemble xenografts more closely than 2D-cultured cells do. Furthermore, we set up a bioluminescence-based spheroid cytotoxicity assay in order to be able to perform dose-response relationship studies in analogy to typical monolayer assays. Applying the established assay, we studied the efficacy of oxaliplatin. Seven of the ten used cell lines showed a significant reduction in the response to oxaliplatin in the 3D-spheroid model compared to the 2D-monolayer model. Therapy studies in selected xenograft models confirmed the response or lack of response to oxaliplatin treatment. Analyses of differentially expressed genes in these models identified CAV1 as a possible marker of oxaliplatin resistance. In conclusion, we established a combined 2D/3D, in vitro/in vivo model system representing the heterogeneity of CRC, which can be used in preclinical research applications.
Project description:Our findings reveal a high degree of both genomic and transcriptomic heterogeneity in established and globally utilized PDAC cell lines, custodial variation induced by growing apparently identical PDAC cell lines in different laboratories, and profound transcriptomic shifts in transitioning from 2D to 3D spheroid growth models. Our findings also call into question the validity of widely available immortalized, non-transformed pancreatic lines as contemporaneous “control” lines in experiments. Further, while patient-derived organoids (PDOs) are known to reflect the cognate in vivo biology of the parental tumor, we identify transcriptomic shifts during ex vivo passage that might hamper their predictive abilities over time. The impact of these findings on rigor and reproducibility of experimental data generated using established preclinical PDAC models between and across laboratories is uncertain, but a matter of concern.
Project description:A genomic expression comparison was done among neural progenitor cells cultured on 2D substrates, 3D porous polystyrene scaffolds, and as 3D neural spheres (in vivo surrogate), with the goal of assessing the feasibility of establishing the meaning of 3D and associated physiological relevance at the molecular level Neural progenitor cells were cultured on 2D surfaces, in 3D scaffolds and as 3D neural spheres. Chemical cues are controlled by coating. Only spacial properties of the culture systems were compared.
Project description:We have established an affordable, flexible and highly reproducible 3D bioprinted CRC model. Histological assessment of Caco-2 cells in 3D bioprints revealed the formation of glandular-like structures which show greater pathomorphological resemblance to tumours than monolayer cultures do. RNA expression profiles in 3D bioprinted cells were marked by upregulation of genes involved in cell adhesion, hypoxia, EGFR/KRAS signaling and downregulation of cell cycle programmes. Testing this 3D experimental platform with three of the most commonly used chemotherapeutics in CRC (5-fluoruracil, oxaliplatin and irinotecan), revealed overall increased resistance compared to 2D cell cultures. Lastly, we demonstrate that our workflow can be successfully extended to primary CRC samples. Thereby, we describe a novel accessible platform for disease modelling and drug testing, which may present an innovative approach in personalised therapeutic screening.
Project description:Background: The main focus of the work was the evaluation of gene expression differences between our established NSCLC 3D cell culture model and the 2D cell culture in regard to the use of our model for drug screening applications. Methods: The non-small cell lung cancer (NSCLC) cell lines Colo699 and A549 were cultivated as monolayer (2D) on cell culture plates for five days or as microtissues (3D) in a hanging-drop system for five and ten days, respectively. Cells and microtissues were harvested and Affymetrix chip analyses were performed with the prior isolated RNA. This was repeated in three independent experiments. Subsequent biostatistical data analyses tested for reproducibility, comparability and significant differences in gene expression profiles between cell lines, experiments and culture methods. Results: The analyses revealed a high interassay correlation within the distinct culture systems, thus proving a high validity of our data. The comparison of 3D versus 2D cell cultures revealed significant differences in RNA expression (979 genes for A549; 1106 genes for Colo699), but the overlap of changes in RNA profiles between the cell lines at the individual gene level was small (149 genes), potentially reflecting overall heterogeneity and their origin, i.e. primary vs pleural effusion. Nevertheless, these RNA expression changes affected most relevant cancer-associated pathways as DNA methylation, cell cycle, rRNA expression and meiosis pathways. Furthermore, the expression differences between 2D and 3D were more evident after longer cultivation time, which supports the hypothesis of cultivation related mechanisms and the usage of long-time cultivation systems. Conclusion: In summary, our data support the need of innovative 3D drug testing systems to close the gap between in-vitro drug screening and in-vivo data. Thus, our 3D NSCLC model might provide a model to address the challenge of microenviroment associated resistance mechanisms, as well as cell-cell interaction related effects.
Project description:3D cultivation of cells lead to changes in morphology of the cells. This is likely to explain the higher radioresistance of cells growing in 3D compared to cells growing in 2D cell culture. Whole genome gene expression is performed to determine genes involved in changes of cell moroholgy and radioresistance. Keywords: comparison of 2D vs. 3D cell culture RNA of cells was isolated four days after growing in the two different cell culture systems
Project description:A transcriptomic expression comparison was done among superior cervical ganglion (SCG) cells cultured on 2D substrates, 3D porous polystyrene scaffolds, and in freshly dissected tissue (in vivo surrogate), with the goal of assessing the feasibility of establishing the meaning of 3D and associated physiological relevance at the molecular level SCG cells were cultured on 2D surfaces and in 3D scaffolds. Chemical cues are controlled by coating. Only spacial properties of the culture systems were compared. Cells from freshly dissected tissue were used as in vivo surrogates for positive control of 3D cells.
Project description:Development of systems allowing the maintenance of native properties of mesenchymal stromal cells (MSC) is a critical challenge for studying physiological functions of skeletal progenitors, as well as towards cellular therapy and regenerative medicine applications. Conventional stem cell culture in monolayer on plastic dishes (2D) is associated with progressive loss of functionality, likely due to the absence of a biomimetic microenvironment and the selection of adherent populations. Here we demonstrate that 2D MSC expansion can be entirely bypassed by culturing freshly isolated bone marrow cells within the pores of 3D scaffolds in a perfusion-based bioreactor system, followed by enzymatic digestion for cell retrieval. The 3D-perfusion system supported MSC growth while maintaining cells of the hematopoietic lineage, and thus generated a cellular environment mimicking some features of the bone marrow stroma. As compared to 2D-expansion, sorted CD45- cells derived from 3D-perfusion culture after the same time (3 weeks) or a similar extent of proliferation (7-8 doublings) maintained a 4.3-fold higher clonogenicity and exhibited a superior differentiation capacity towards all typical mesenchymal lineages, with similar immunomodulatory function in vitro. Transcriptomic analysis performed on MSC from 5 donors validated the robustness of the process and indicated a reduced inter-donor variability as well as a significant upregulation of multipotency-related gene clusters following 3D-perfusion as compared to 2D expansion. The described system offers a model to study how factors of a 3D engineered niche may regulate MSC function and, by streamlining conventional labor-intensive processes, is prone to automation and scalability within closed bioreactor systems. Nucleated cells were isolated from 5 fresh human bone marrow aspirates by means of red blood cells lyses buffer and then were seeded into a 3D perfusion bioreactor system using a pure hydroxyapatite 3D scaffold and in conventional Petri dishes (2D). After culture for 19 days, cells from both systems were enzymatically retrieved and sorted using anti-CD45-coated magnetic beads. Total RNA was extracted from CD45- cells, QCed and hybridized to Affymetrix microarrays.