Characteristic gene expression induced by polyurethane foam/spheroid culture of hepatoma cell line, Hep G2 as a promising cell source for bioartificial liver.
OBJECTIVE
Polyurethane foam (PUF)/ spheroid-culture can improve liver-specific functions of hepatoma cell line, Hep G2. Therefore, gene expression profile in the PUF/spheroid culture is hypothesized to be different from that in the monolayer culture. The aim of this study is to clarify the characteristic gene expression in PUF/spheroid-cultured Hep G2 cells, as a cell source for bioartificial liver (BAL), using microarray analysis.


METHODS
Morphological change and liver specific functions of ammonia removal rate and albumin synthesis rate of Hep G2 were compared between in a monolayer or PUF/spheroid culture. Microarray analysis was performed using cDNA microarrays made in Hitachi Software Engineering Co., Ltd., (Yokohama, Japan), which contains a total of 1,281 cDNA clones.


RESULTS
The ammonia removal rate of Hep G2 spheroids increased to 369%, and the albumin synthesis rate of Hep G2 spheroids also increased 311% when compared with monolayer culture. In addition, the ammonia removal capacity of primary human hepatocytes in the PUF/spheroid culture was superior to that in the monolayer culture. The microarray analysis demonstrated that the PUF/spheroid-cultured Hep G2 cells expressed 39 up-regulated (more than 3.0-fold) and 31 down-regulated (less than 0.333-fold) genes. Among the 70 genes differentially expressed in PUF/spheroid cultured Hep G2 cells, subsets of glutathione S-transferase- and angio-tensin-related genes were drastically up-regulated, on the other hand, subsets of assigned for growth factor, glucocorticoid, and stress response, were down-regulated.


CONCLUSIONS
Hepatoma cell line, Hep G2 cells in the PUF/spheroid culture is a promising hepatocyte source for BAL. Microarray analysis revealed a number of characteristic genes altered by the PUF/spheroid.
Shimada
Mitsuo
M
Department of Surgery, University of Tokushima, Kuramoto 3-18-15, Tokushima 770-8503, Japan. mshimada@clin.med.tokushima-u.ac.jp
Yamashita
Yo-ichi
Y
Tanaka
Shinji
S
Shirabe
Ken
K
Nakazawa
Kohji
K
Ijima
Hiroyuki
H
Sakiyama
Ryoichi
R
Fukuda
Junji
J
Funatsu
Kazumori
K
Sugimachi
Keizo
K
D000641:Ammonia / Q000378:metabolism; D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D015870:Gene Expression / Q000187:drug effects*; D020869:Gene Expression Profiling; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008113:Liver Neoplasms; D019164:Liver, Artificial; D020411:Oligonucleotide Array Sequence Analysis; D011140:Polyurethanes / Q000494:pharmacology*; D018874:Spheroids, Cellular; D014407:Tumor Cells, Cultured
D011140:Polyurethanes; D000641:Ammonia; C028279:polyurethane foam