Traditionally, the anti-aging effects of telomerase have been poorly explored because of its unfortunate cancer-promoting activity. Consequently, the researchers genetically engineered cancer-resistant mice by up-regulating their expression of tumor suppressor proteins p53, p16, and p19ARF.
TElomerase Reverse Transcriptase (TERT, or just ‘telomerase’) was additionally overexpressed to observe the anti-aging effects of increasing its concentrations in the cell. It was found that TERT overexpression improved the fitness of epithelial barriers (particularly the skin and the intestine) and produced a systemic delay in aging, as well as an actual extension of the median life span.
Also, the genetically enhanced mice showed a better preservation of both the thickness of the epidermis and of the subcutaneous fat layer compared to the controls. What this means is, if they were humans, one of the main factors that is the cause of the appearance of old age, i.e. subcutaneous fat loss, would be somewhat reduced.
Interestingly, with regard to their lifespans: The mice that had their tumor suppression capabilities enhanced, but lacked TERT enhancement, saw no increase in lifespan. Those mice with both modifications saw a 26% increase in median lifespan. Of these mice, those that did not die of cancer (i.e., those that could be considered to have died of ‘old age’) experienced a 38% increase in median lifespan.