Telomerase activity in clinically normal dogs and dogs with malignant lymphoma

Objectives-To determine whether telomerase activity was present in lymph no des, buffy coat, and serum samples from dogs with malignant lymphoma (ML) a nd in liver, lymph node, buffy coat, and serum samples from clinically norm al dogs Sample Population-Tissue specimens and blood samples were obtained from 11 clinically normal adult dogs (age range, 1 to 4 years) and 14 client-owned dogs with ML. Procedure-The telomere repeat amplification protocol assay was used to quan tify telomerase activity in the tissues from clinically normal dogs and dog s with ML. Results-Of 11 clinically normal dogs, 8 had lymph node samples, 5 had liver samples, and 1 had buffy coat samples with detectable telomerase activity. None of the serum samples from the clinically normal dogs had detectable t elomerase activity. Of 14 dogs with ML, 9 had lymph node samples, 3 had buf fy coat samples, and 1 had serum samples with measurable telomerase activit y. Conclusions and Clinical Relevance-Telomerase activity was not specific to tumor cells and overlapped with that found in cells from clinically normal dogs. Telomerase activity in neoplastic lymph nodes was not substantially d ifferent from that found in lymph nodes from clinically normal dogs. The de termination of telomerase activity cannot be used as a sole diagnostic test for cancer. Therapeutic modalities directed toward the telomerase enzyme m ay not be feasible in dogs, because somatic tissues from clinically normal dogs possess variable amounts of telomerase activity.