Expression of galectin-3 in cells exposed to stress-roles of jun and NF-kappaB.
OBJECTIVE
Galectin-3 is an interesting intracellular lectin that appears to be involved in numerous physiological processes. We have analyzed expression of galectin-3 in glioblastoma cells exposed to heat-shock, alkylating agents, UV-C radiation and subculturing (trypsinization).


METHODS
Protein levels of galectin-3 were measured by western-blot analysis using M3/38 monoclonal antibody. The involvement of transcription factors NF-kappaB and Jun in the induction of galectin-3 was addressed using specific inhibitor of NF-kappaB (zL(3)-vs) and antisense-jun oligonucleotides.


RESULTS
Exposure of cells to heat-shock or subculturing (trypsinization) decreased levels of galectin-3 to approximately 50%. Alkylating damage and UV-C irradiation caused an increase in the expression of galectin-3. Both inhibition of Jun by antisense-jun oligonucleotides, and inhibition of NF-kappaB by specific proteasomal inhibitor attenuated the induction of galectin-3 by UV-light, but with somewhat different kinetics.


CONCLUSIONS
We have found that different forms of cellular stress have different effects on the expression of galectin-3. Heat-shock and subculturing decrease, while alkylating agents and UV-light increase galectin 3. NF-kappaB and Jun were shown to be involved in the induction of galectin-3 by UV-light, which is a first demonstration that these transcriptional factors are involved in the regulation of galectin-3 expression.
Dumic
J
J
Department of Biochemistry and Molecular Biology, Faculty of Pharmacy and Biochemistry, University of Zagreb, Ante Kovavica 1, 10000 Zagreb, Croatia.
Lauc
G
G
Flögel
M
M
D000477:Alkylating Agents / Q000494:pharmacology; D000943:Antigens, Differentiation / Q000235:genetics*; D037502:Galectin 3; D005786:Gene Expression Regulation; D018869:Heat-Shock Response; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D014357:Trypsin / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays
D000477:Alkylating Agents; D000943:Antigens, Differentiation; D037502:Galectin 3; D016328:NF-kappa B; D016755:Proto-Oncogene Proteins c-jun; D014357:Trypsin