Telomere Lengths and Telomerase Activity in Dog Tissues: A Potential Model System to Study Human Telomere and Telomerase Biology

Abstract

Studies on telomere and telomerase biology are fundamental to the understanding of aging and age-related diseases such as cancer. However, human studies have been hindered by differences in telomere biology between humans and the classical murine animal model system. In this paper, we describe basic studies of telomere length and telomerase activity in canine normal and neoplastic tissues and propose the dog as an alternative model system. Briefly, telomere lengths were measured in normal canine peripheral blood mononuclear cells (PBMCs), a range of normal canine tissues, and in a panel of naturally occurring soft tissue tumours by terminal restriction fragment (TRF) analysis. Further, telomerase activity was measured in canine cell lines and multiple canine tissues using a combined polymerase chain reaction/enzyme-linked immunosorbent assay method. TRF analysis in canine PBMCs and tissues demonstrated mean TRF lengths to range between 12 and 23 kbp with heterogeneity in telomere lengths being observed in a range of normal somatic tissues. In soft tissue sarcomas, two subgroups were identified with mean TRFs of 22.2 and 18.2 kbp. Telomerase activity in canine tissue was present in tumour tissue and testis with little or no activity in normal somatic tissues. These results suggest that the dog telomere biology is similar to that in humans and may represent an alternative model system for studying telomere biology and telomerase-targeted anticancer therapies.

Kısa (Chihuahua köpek) ve Uzun (Asya fili) Ömürlü Hayvanlarda Artan Yaş İle Birlikte Telomerik Yıpranma

“…By contrast, we did find a significant negative correlation between age and telomere length in Chihuahua dogs (n=89). A shortening of telomeres with cell replications of in vitro canine fibroblasts has been detected [22] , and Fick et al [21] showed a connection between telomere loss with age in 15 dog breeds (n=175), similar to our results. Furthermore, Fick et al [21] reported that different dog breeds varied in telomere length, which contributed to average lifespan.…”

Keçilerin Enzootik Intranazal Tümörlerinde Telomeraz Enziminin Düzeyinin Belirlenmesi

“…This activity protects the integrity of chromosomes from digestion by exonucleases, fusion to the neighboring chromosomes and occurring the chromosomal defects [29,30] . Possible relation between carcinogenesis and telomere dysfunctions was reported [31,32] .…”

Dogs: Active Role Model for Cancer Studies—A Review

“…Dogs develop spontaneous tumors that display behavior and histo-pathological characteristics to human tumors [6][7][8]. For example, in dogs, studying about the role of inhibition of telomere size shortening plays in cell immortalization and proliferation is relevant, because dog chromosomal telomeres closely resemble human telomeres than murine telomeres [9]. Among the practical benefits of clinical investigation of cancer in dogs is the fact that due to their shorter life span, clinical intervention is easily studied over a condensed period of time.…”