Canine telomerase reverse transcriptase (cTERT) (cTERT)

Canine telomerase reverse transcriptase (cTERT) is the catalytic subunit of the telomerase enzyme complex, a ribonucleoprotein responsible for maintaining telomere length by adding TTAGGG repeats to chromosome ends (UniProt). In healthy adult dogs, cTERT expression is tightly regulated and largely restricted to germline cells and certain stem cell populations, but it is reactivated in over 90% of canine malignant tumors, including osteosarcoma, lymphoma, and hemangiosarcoma (Peruzzi et al., 2010). This selective overexpression makes cTERT a highly attractive immune-mediated therapeutic target, particularly for cancer vaccines designed to elicit a T-cell response against tumor cells. Current therapeutic strategies involve DNA plasmids (e.g., V934) or adenoviral vectors (e.g., V930) that encode the cTERT protein to bypass peripheral tolerance and activate cytotoxic T lymphocytes (Gavazza et al., 2020). Clinical studies in veterinary oncology have demonstrated that these cTERT-targeting immunotherapies are well-tolerated and can significantly extend survival times in dogs with aggressive cancers when used in conjunction with standard chemotherapy. As a nearly universal tumor-associated antigen, cTERT represents a cornerstone for developing broad-spectrum canine cancer immunotherapies (Evvivax).

Other names

Telomerase reverse transcriptaseTERTdTERTCanine TERTTelomerase catalytic subunit

Induction of a targeted immune response where the vaccine-delivered cTERT genetic sequence is expressed and presented as peptides on MHC class I molecules, stimulating the expansion of antigen-specific CD8+ cytotoxic T lymphocytes that recognize and eliminate telomerase-positive malignant cells (Peruzzi et al., 2010; Gavazza et al., 2020).