Human telomerase RNA component (TERC) (hTR)

Human telomerase RNA component (hTR), also known as TERC, is a non-coding RNA that serves as an essential structural and functional component of the telomerase enzyme complex (NCBI Gene: 7012). The hTR template region contains a specific nucleotide sequence (5'-CUAACCCUAAC-3') that provides the blueprint for the synthesis of telomeric DNA repeats (TTAGGG) by the catalytic subunit, human telomerase reverse transcriptase (hTERT) (Shay & Wright, 2019). In most somatic cells, telomerase activity is low or absent, leading to progressive telomere shortening and eventual senescence. However, telomerase is highly upregulated in approximately 90% of human cancers, enabling indefinite cellular proliferation and immortality (Herbert et al., 2005). Therapeutic strategies targeting the hTR template region, such as the oligonucleotide inhibitor imetelstat, work by competitively binding to the RNA template, thereby preventing the telomerase complex from extending telomeres (FDA, 2024). This inhibition leads to telomere attrition and eventual apoptosis or senescence of malignant cells, particularly in hematologic malignancies like myelodysplastic syndromes (MDS).

Other names

TERChTRhTercTRTelomerase RNA componentTelomerase RNA templatehTR template region

Competitive inhibition of telomerase activity by binding to the hTR template region, preventing telomere elongation.