PIN2 (TERF1) interacting telomerase inhibitor 1 (PINX1)

PIN2 (TERF1) interacting telomerase inhibitor 1 (PINX1) is a nuclear protein that plays a crucial role in the negative regulation of telomerase activity and telomere length maintenance, contributing directly to chromosome stability and acting as a haploinsufficient tumor suppressor[1][2][4][6]. PINX1 binds to the telomerase catalytic subunit TERT and telomerase RNA component (hTR), thereby inhibiting the addition of telomeric repeats and preventing abnormal telomere elongation—a process frequently dysregulated in cancer[4][6]. Loss or reduction of PINX1 leads to increased telomerase activity, telomere lengthening, and chromosomal instability, which are hallmarks of many human cancers[4][6]. Conversely, overexpression of PINX1 can induce cellular crisis and enhance sensitivity to chemotherapeutic agents[4]. PINX1 is being explored both as a biomarker for cancer prognosis and a potential novel therapeutic target, mainly via modulation of telomerase and telomere dynamics[4][6].

Other names

PIN2/TERF1-interacting telomerase inhibitor 1Pin2-interacting protein 1PINX1_HUMANPINX1 geneHGNC:30046ENSG00000258724NCBI Gene:54984

- Inhibition of telomerase enzymatic activity (by direct interaction with TERT/hTR complex at telomeres) - Tumor suppressor function via restoration of normal telomere length and chromosomal stability - Sensitization of cancer cells to DNA-damaging agents/chemotherapeutics (by promoting crisis/cell death due to telomere dysfunction)