Telomerase upregulates expression levels of interleukin (IL)-1α, IL-1β, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor in normal human fibroblasts

Expression of human telomerase reverse transcriptase (hTERT) in normal human fibroblast cell strain, TIG-3, extends their replicative life span. We found that expression levels of interleukin (IL)-1α, IL-1β, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA were up-regulated in hTERT-induced fibroblasts irrespective of population doubling level (PDL). Expression levels of these cytokines were low in growing young TIG-3 cells and in control vector-transfected TIG-3 cells but were up-regulated in growth-arrested young cells maintained at high cell density. In senescent TIG-3 cells, expression of IL-1β, IL-6, and GM-CSF was moderately increased. These results indicate that the introduction of hTERT into normal fibroblasts up-regulates the expression of some inflammatory cytokines, and caution should be paid when introducing the hTERT gene to establish cell lines with normal phenotype.