Expression of galectin-3 in cells exposed to stress-roles of jun and NF-kappaB

Abstract

Background/aims: 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.