[The anti-tumor mechanisms in long-lived rodents]

Rodents, including the nude mice with congenital aplasia of the thymus, cancer-resistant naked mole rat (Heterocephalus glaber) and blind mole rat (Spalax galili), are important model organisms that are widely used in biomedical research. The aging process is closely related to cancer incidence in mammals and the aging degree is positively correlated with the risk of cancer. Since rodents account for 40% of mammals, study of the unique antitumor mechanism in long-lived rodents is very important. Replicative senescence is anti-tumor mechanism that prevalently exist in rodents, however, unique anti-tumor mechanisms have been found in naked mole-rats and blind mole-rats. The cancer resistance of Spalax galili is mediated by cell-released IFN-β which activates p53 and Rb signaling pathway and the cells undergoes concerted cell death while that of Heterocephalus glaber is mediated by high molecular weight hyaluronan (HMW-HA) which causes contact inhibition. In addition, highly expressed pro-cell-death and anti-inflammation related genes are found in the genome of both naked mole-rats and blind mole-rats. In this review, we summarize the anti-tumor mechanisms in both Heterocephalus glaber and Spalax galili, which may provide information for related research.