title: Influence of a three-dimensional, microarray environment on human cell culture in drug screening systems.
abstract: We have used a modified 3D cellular microarray platform for the high-throughput analysis of growth, cytotoxicity, and protein expression profile of a human hepatocellular carcinoma cell line, HepG2, in alginate. The results obtained were compared to analogous studies in 2D and 3D environments at the microtiter scale. The antiproliferative effects of four drugs, tamoxifen, 5-fluorouracil, doxorubicin, and amitriptyline, were studied as a function of seeding density in the three different culture platforms. The chemosensitivity of HepG2 cells to all four compounds decreased substantially with increasing cell number in the 2D and 3D microtiter-based cultures, while no seeding density dependence was observed in the IC(50) values obtained in the 3D microarray culture platform. These results can be rationalized based on the development of confluence-dependent resistance in cultures where proliferation is restricted by cell-cell contacts and nutrient availability, as is the case for both of the microtiter-based cultures. Additionally, further development of an on-chip, in-cell immunofluorescence assay provided quantitative data on the levels of specific target proteins involved in proliferation, adhesion, angiogenesis and drug metabolism, and was used to compare expression profiles between 2D and 3D environments. The up-regulation of several CYP450 enzymes, β1-integrin and vascular endothelial growth factor (VEGF) in the 3D microarray cultures suggests that this platform provides a more in vivo-like environment allowing cells to approach their natural phenotype.
authors.affiliation: Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
authors.forename: Luciana
authors.initials: L
authors.lastname: Meli
authors.forename: Eric T
authors.initials: ET
authors.lastname: Jordan
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Clark
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Linhardt
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Dordick
mesh_terms: D000464:Alginates / Q000737:chemistry; D000639:Amitriptyline / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival; D002478:Cells, Cultured; D046508:Culture Techniques / Q000379:methods*; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor / Q000295:instrumentation* / Q000379:methods; D005455:Fluorescent Antibody Technique; D005472:Fluorouracil / Q000494:pharmacology; D020723:Glucuronic Acid / Q000737:chemistry; D056945:Hep G2 Cells; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000473:pathology; D046228:Microarray Analysis / Q000295:instrumentation* / Q000379:methods*; D018613:Microscopy, Confocal; D010641:Phenotype; D013629:Tamoxifen / Q000494:pharmacology; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D000464:Alginates; D000970:Antineoplastic Agents; D006603:Hexuronic Acids; D019012:Integrin beta1; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D013629:Tamoxifen; D000639:Amitriptyline; D004317:Doxorubicin; D020723:Glucuronic Acid; D003577:Cytochrome P-450 Enzyme System; D005472:Fluorouracil