New Preclinical Data for THIO in BRAF-Mutant Mouse Melanoma Models

Source: Business Wire, April 2018

A hallmark of several cancer types, including melanoma, is increased telomerase activation. Telomerase is an enzyme responsible for elongating telomeres which protect the integrity of chromosome ends during cell replication. While absent in most normal cells, telomerase is highly active in cancer cells, driving continuous cell divisions.
“Telomerase is an almost universal oncology target. In the present study, we provide a scientific rationale for the development of new clinical cancer treatments based on targeting telomeres in cancer cells,” said Jerry W. Shay, co-author of the study, and professor of Cell Biology at UT Southwestern Medical Center.
Meenhard Herlyn, D.V.M., D.Sc., Caspar Wistar Professor in Melanoma Research and director of The Wistar Institute Melanoma Research Center, and his collaborators used a modified telomerase substrate they had previously described, 6-thio-2’-deoxyguanosine or 6-thio-dG (THIO), to utilize telomerase to induce telomere dysfunction. They demonstrated that THIO induced cell death in melanoma cells harboring BRAF gene mutations and impaired tumor growth in several BRAF-mutant mouse melanoma models without affecting the viability of normal skin cells.