Table 1.

The main current state of research and key studies on telomerase modulators in cancer; different approaches and levels of evidence from animal and human studies.

Modulator	Mechanism	Evidence in Animals	Evidence in Humans
Imetelstat (GRN163L)	Telomerase inhibitor.	Inhibited tumor growth and metastasis in mouse models of various cancers, including breast and lung cancer.	Phase II clinical trials showed partial responses and disease stabilization in patients with myelofibrosis and certain solid tumors.
BIBR1532	Telomerase inhibitor.	Suppressed tumor growth in xenograft models of glioblastoma and leukemia.	Preclinical studies only, no clinical trials yet.
6-thio-2′-deoxyguanosine (6-thio-dG)	Telomerase substrate that induces telomere dysfunction.	Reduced tumor growth and improved survival in mouse models of glioblastoma and melanoma.	Preclinical studies only, showing promise for future clinical trials.
Curcumin	Natural compound, inhibits telomerase activity.	Decreased telomerase activity and tumor growth in mouse models of prostate cancer.	Limited clinical studies suggest potential benefits, but more research is needed.
Resveratrol	Natural compound, modulates telomerase and telomeres.	Extended lifespan and reduced tumor incidence in animal models; effects on telomerase activity are mixed.	Some clinical trials indicate potential anticancer effects, though data on telomerase modulation in humans is limited.
RHPS4	G-quadruplex stabilizer, inhibits telomerase.	Reduced tumor growth and telomere shortening in mouse models of melanoma and glioblastoma.	Preclinical studies only, showing potential for clinical development.
TA-65	Telomerase activator, derived from Astragalus membranaceus.	Improved health span and telomere length in aged mice; data on cancer effects are mixed.	Some human studies suggest telomere lengthening and improved markers of aging, but data on cancer effects is limited and controversial.
Tert promoter mutations	Genetic modifications to increase telomerase expression.	Extended lifespan and delayed cancer onset in some transgenic mouse models; increased cancer risk in others.	Observed in various cancers; some patients show increased telomerase activity, contributing to tumor progression.
GRNVAC1	Telomerase-based dendritic cell vaccine.	Induced immune response and reduced tumor burden in mouse models of prostate cancer.	Phase II clinical trials showed immune activation and potential clinical benefits in patients with acute myeloid leukemia.
Cycloastragenol	Telomerase activator, another Astragalus extract.	Improved telomere length and reduced oxidative stress in aged mice; effects on cancer are unclear.	Some small human studies indicate telomere lengthening, but more research is needed to determine cancer-related effects.