RNA expression of human telomerase subunits TR and TERT is differentially affected by melatonin receptor agonists in the MCF-7 tumor cell line

The RNA expression levels of human catalytic subunit (TERT) and the RNA subunit (TR) of telomerase were analysed after treatment with the agonists of the membrane receptor (S 20098) and the nuclear receptor (CGP 52608) for melatonin in the MCF-7 human breast tumor cell line. Neither membrane nor nuclear signalling affected the RNA steady-state levels of the TR subunit of telomerase. On the contrary, we observed a significant decreased in the RNA levels of TERT after treatment with CGP 52608 while S 20098 produced a significant increase in the RNA levels of TERT. These results support a cross-talk between membrane and nuclear melatonin signalling and provide new data on the hormonal regulation of telomerase function.