The effect of 50 Hz magnetic field on GCSmRNA expression in lymphoma B cell by mRNA differential display.
Magnetic fields (MFs) of various characteristics can lead to plethora effects in biological system. From a molecular point of view, we hypothesized that there must be a fundamental difference in gene expression between the MF exposed and the unexposed cell. To identify the classes of genes that are regulated, 0.8 mT 50 Hz MF-induced changes in gene expression were examined in a Daudi cell culture using differential display and reverse transcriptase-polymerase chain reaction. A candidate cDNA (signatured as MF-CB) that was observed in the sham-exposed but not in MF-exposed cultures was recovered and reamplified. After verification by Northern blot, the cDNA was cloned and sequenced. It was found that 254-base pair of 5'-end MF-CB cDNA clone was identical to gcs in open reading frame (ORF) range. Based on the preliminarily sequence, the prolonged length of 5'-end MF-CB cDNA was obtained by PCR amplification and its sequence analysis showed the same results as its original fragment. In order to further determine whether MF-CB cDNA is from gcs, two Northern blots were probed with gcs and MF-CB cDNA, respectively, and the data revealed signals of the same size and expression pattern on the two probe filters, which demonstrated that MF-CB is an EST (expression sequence tag) of gcs. gcs is a gene, identified recently (GenBank accession number D89866), encoding ceramide glucosyltransferase (GCS), which has been implicated as a causal element in human cell growth and differentiation. In an additional experiment, time-dependent changes in the transcription of gcs induced by 0.8 mT MF were observed by Northern blot with a sharp and reproducible inhibition effect after 20 min exposure and a reduction after 20-24 h exposure. The study demonstrates for the first time that 50 Hz MF can lead to changes in gcs transcription, which provides a new clue to elucidate the mechanism by which MF influence cell growth and differentiation.
Wu
R Y
RY
Microwave Lab, Medical College, Zhejiang University, Hangzhou 310031, P.R. China.
Chiang
H
H
Hu
G L
GL
Zeng
Q L
QL
Bao
J L
JL
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D002051:Burkitt Lymphoma / Q000235:genetics / Q000473:pathology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004790:Enzyme Induction / Q000528:radiation effects; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects*; D005964:Glucosyltransferases / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D008280:Magnetics; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis*; D012334:RNA, Neoplasm / Q000096:biosynthesis*; D012689:Sequence Homology, Nucleic Acid; D013382:Subtraction Technique; D014158:Transcription, Genetic / Q000528:radiation effects*; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000528:radiation effects
D018076:DNA, Complementary; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase