Original Articles
Copyright ©The Author(s) 1998. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 15, 1998; 4(2): 121-124
Published online Apr 15, 1998. doi: 10.3748/wjg.v4.i2.121
Serum deprivation enhances DNA synthesis of human hepatoma SMMC-7721 cells
Shi-Ming Jiang, Zhao-Hui Xu
Shi-Ming Jiang, Zhao-Hui Xu, Biology Department, the Provincial Key Laboratory of Animal Stress, Shandong Normal University, Jinan 250014, Shandong Province, China
Shi-Ming Jiang, male, born on 1961-11-26 in Zhaoyuan City, Shan-dong Province, Han nationality, graduated from Shandong Normal University as a postgraduate in 1985, Associate Professor of Cell Biology, having 30 papers and one book published. Presented at the First International Symposium on Bioanalytical Chemistry, Xi’an, China, July 26-30, 1995.
Author contributions: All authors contributed equally to the work.
Correspondence to: Shi-Ming Jiang, Biology Department, the Provincial Key Laboratory of Animal Stress, Shandong Normal University, Jinan 250014, Shandong Province, China. jiangsm@hotmail.com
Received: October 28, 1997
Revised: December 20, 1997
Accepted: January 20, 1998
Published online: April 15, 1998

AIM: To determine the relationship between serum deprivation or serum levels and cell proliferation of human hepatoma SMMC-7721 cells.

METHODS: Human hepatoma SMMC-7721 cells were grown in RPMI 1640 supplemented with 10% fetal calf serum (FCS) in 5% CO2 incubator at 37 °C for 24 h, and culture media were replaced to serum-free or different serum FCS levels (2.5%, 5%, 10%, 20% and 25%). Six h, 12 h, 18 h and 24 h after the culture, the cells were incorporated [3H]-TdR for 4 h. At last [3H]-TdR incorporation was detected with liquid scintillation counting.

RESULTS: DNA synthesis of SMMC-7721 cells could be sharply stimulated by short-time (6 h) serum deprivation (the cpm value of 3H-TdR incorporation of cells in serum-free was 39.32-fold higher than cells in 25% serum), and the incorporation of 3H-TdR was negatively related to the serum levels. Longer-time serum starvation (12 h, 18 h and 24 h) also greatly stimulated DNA synthesis, although the cpm value of 3H-TdR incroporation was less than that in 6 h serum deprivation. Morphology of cells cultured in different serum levels also showed significant difference.

CONCLUSIONS: Compared with other cell lines such as BEL7404 and Swiss 3T3, human hepatoma SMMC-7721 cells had different response to the serum deprivation. Short-time serum deprivation could greatly stimulate DNA synthesis of human hepatoma SMMC-7721 cells. Precautions must be given to the changes of serum levels for the detection of growth factors and drugs using SMMC-7721 cells as a model.

Keywords: liver neoplasms, carcinoma, hepatocellular, DNA, neoplasm/biosynthesis, SMMC-7721, tumor cell, cultured, cell proliferation, growth factors