title: Optimization of Albumin Secretion and Metabolic Activity of Cytochrome P450 1A1 of Human Hepatoblastoma HepG2 Cells in Multicellular Spheroids by Controlling Spheroid Size.
abstract: Multicellular spheroids are useful as three-dimensional cell culture systems and for cell-based therapies. Their successful application requires an understanding of the consequences of spheroid size for cellular functions. In the present study, we prepared multicellular spheroids of different sizes using the human hepatoblastoma HepG2 cells, as hepatocytes are frequently used for in vitro drug screening and cell-based therapy. Precise polydimethylsiloxane-based microwells with widths of 360, 450, 560, and 770 µm were fabricated using a micromolding technique. Incubation of HepG2 cells in cell culture plates containing the microwells resulted in the formation of HepG2 spheroids with average diameters of 195, 320, 493, and 548 µm. The cell number per spheroid positively correlated with its diameter, and the viability of HepG2 cells was 94% or above for all samples. The smallest HepG2 spheroids showed the highest albumin secretion. On the other hand, the metabolic activity of 7-ethoxyresorufin, a fluorometric substrate for CYP1A1, increased with increasing spheroid size. These results indicate that controlling spheroid size is important when preparing HepG2 spheroids and that the size of HepG2 spheroids greatly influences the cellular function of HepG2 cells in the spheroids.
authors.affiliation: Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nishikawa
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Makiya
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Yuka
authors.initials: Y
authors.lastname: Ogino
authors.forename: Kosuke
authors.initials: K
authors.lastname: Kusamori
authors.forename: Narumi
authors.initials: N
authors.lastname: Mizuno
authors.forename: Yuya
authors.initials: Y
authors.lastname: Mizukami
authors.forename: Kazunori
authors.initials: K
authors.lastname: Shimizu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Konishi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Takakura
mesh_terms: D000418:Albumins / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods; D002470:Cell Survival; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism*; D004129:Dimethylpolysiloxanes; D056945:Hep G2 Cells; D018197:Hepatoblastoma / Q000378:metabolism; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000166:cytology* / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism; D008954:Models, Biological; D010078:Oxazines / Q000378:metabolism; D018874:Spheroids, Cellular
chemical_list: D000418:Albumins; D004129:Dimethylpolysiloxanes; D010078:Oxazines; C007649:ethoxyresorufin; C013830:baysilon; C569463:CYP1A1 protein, human; D019363:Cytochrome P-450 CYP1A1