Lex, K. et al. PNAS 117, 15066–15074 (2020)
Cancer incidence increases with age as telomeres get shorter. However little is known about how telomere shortening may lead to cancer.
Using zebrafish chimeras in which blastula cells from donor embryos capable of giving rise to melanoma were transplanted into wild-type embryos or telomerase-deficient embryos (tert−/−) with shorter telomeres, a new study demonstrates that telomere shortening promotes cancer in a noncell autonomous manner. The results also indicate that tert−/− cells increase tumor incidence and progression in zebrafish by creating a systemic senescent and inflammatory environment. Additional investigation in animal models will be needed to confirm that telomere shortening promotes cancer in aging and identify the molecular mechanisms underlying this process.