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Inhibitory effects of thioredoxin reductase antisense RNA on the growth of human hepatocellular carcinoma cells
Author(s) -
Gan Lu,
Yang XiangLiang,
Liu Qiong,
Xu HuiBi
Publication year - 2005
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.20585
Subject(s) - thioredoxin reductase , antisense rna , microbiology and biotechnology , telomerase reverse transcriptase , sense (electronics) , biology , transfection , rna , thioredoxin , messenger rna , cell cycle , telomerase , chemistry , cell , biochemistry , enzyme , gene
Thioredoxin reductase (TrxR) in conjunction with thioredoxin (Trx) is a ubiquitous intracellular oxidoreductase system with antioxidant and redox regulatory roles. In some human tumors, the thioredoxin system is found overexpressed. We have used an antisense approach to investigate whether inhibition of TrxR overexpression can suppress the growth of human hepatocellular carcinoma SMMC‐7721 cells. TrxR cDNA fragment was inserted in the antisense direction into pcDNA3.1/myc‐His and SMMC‐7721 cells were stably transfected with the plasmid construct. The results showed that TrxR antisense RNA could significantly reduce TrxR mRNA level and activity, and suppress the growth of SMMC‐7721 cells. Cell‐cycle analysis showed G 2 /M phase arrest in SMMC‐7721 cells transfected with TrxR antisense plasmid. TrxR antisense RNA could significantly increase p53 mRNA level and decrease Bcl‐2 mRNA level by reverse transcriptase‐polymerase chain reaction (RT‐PCR). Furthermore a significant decrease in human telomerase reverse transcriptase (hTERT) mRNA level was found in SMMC‐7721 cells transfected with TrxR antisense plasmid. Flow cytometry and telomere fluorescence in situ hybridization (Flow FISH) showed that TrxR antisense RNA could significantly reduce the telomere fluorescence in SMMC‐7721 cells. The results suggested that TrxR antisene RNA inhibited the growth of SMMC‐7721 cells through an accumulation of cell cycle at G 2 /M phase, an increase in p53 mRNA level and a reduction in telomere fluorescence and Bcl‐2, hTERT mRNA levels. © 2005 Wiley‐Liss, Inc.