Triptolide Boosts Cancer Drug Effectiveness

Johns Hopkins researchers found a compound that blocks an enzyme that makes DNA-targeting cancer drugs less effective in preclinical models.

Updated on Nov. 3, 2026 in Cancer

Bold flat-color vector editorial illustration of two glass vials beside translucent teal molecular shapes and a pipette on a pale surface. — Johns Hopkins researchers found that triptolide blocks an enzyme that breaks down DNA-targeting cancer drugs, making them more effective in preclinical models. AI Illustration. Upload story photo >

Johns Hopkins researchers reported that triptolide, a compound derived from Tripterygium wilfordii, inhibits the enzyme DCTPP1 in preclinical models. Combining triptolide with the DNMT inhibitor decitabine increased tumor suppressor gene reactivation and cancer cell death in laboratory and animal models.

Why it matters

DNMT inhibitors such as decitabine and azacitidine have worked against certain blood cancers but have had more limited success against solid tumors. Higher DCTPP1 levels were associated with greater resistance to these drugs, suggesting the enzyme is a barrier to treatment.

The findings come from laboratory and animal studies, not human trials, and the magnitude of improvement in clinical outcomes remains unmeasured. Researchers have not yet determined whether DCTPP1 inhibitors can be made potent and safe enough for human use.

The players

Johns Hopkins Sidney Kimmel Comprehensive Cancer Center

A major cancer research center at Johns Hopkins University in Baltimore where the study was conducted.

The details

Triptolide blocks DCTPP1, an enzyme that breaks down the active form of DNMT inhibitors before they can be incorporated into DNA, allowing more of the drug to reach its target. Earlier research found that experimental DCTPP1 inhibitors combined with decitabine increased the sensitivity of prostate cancer cells to the drug.

Health Landscape

DNMT inhibitors decitabine and azacitidine have been used clinically, mainly for certain blood cancers, while their results in solid tumors have been more limited. This preclinical work points to a way of improving those drugs by targeting the enzyme that degrades them.

The results are preclinical, so no changes to current cancer treatment are available to patients yet. Patients receiving DNMT inhibitors may eventually benefit if DCTPP1-targeting combinations advance into human trials.

The takeaway

Drug resistance is a major obstacle in cancer treatment, and identifying the enzymes that degrade a drug can reveal new combination strategies. Patients should discuss any emerging therapies with their oncologists rather than seek unproven compounds.