Mebendazole Suppresses Colorectal Tumors with Low PNLDC1 Levels, Preclinical Study Finds
Laboratory study: colorectal tumors low in the PNLDC1 protein grow more aggressively — and the antiparasitic drug mebendazole curbed that excess growth in cancer cells, in mice, and in tumor samples taken from patients. No patients were treated.
By Sanare Lab · September 24, 2026 · 2 min read
Key Takeaway
Colorectal tumors with low levels of a protein called PNLDC1 grow more aggressively. In a new laboratory study, the antiparasitic drug mebendazole suppressed that excess growth — in cancer cells in a dish, in mice carrying human tumors, and in clusters of tumor cells taken from real patients. Laboratory evidence only: no patients were treated, and the size of the effect is not yet known.
Reporting in the journal Exploration (September 21, 2026), a team led by Lexin Liu found that PNLDC1 — a protein that helps break down genetic messages (mRNA) inside cells — is present at unusually low levels in 91 colorectal cancer tissue samples. PNLDC1 normally acts as a brake on tumor growth: it destroys the messages of a gene called TUBB4B, which makes tubulin, a building-block protein that cancer cells need in order to divide. When PNLDC1 runs low, tubulin goes unchecked and tumors grow faster.
That is where mebendazole comes in: the drug blocks TUBB4B, and it curbed the extra growth of low-PNLDC1 tumors in all three laboratory models. The authors' summary reports no effect sizes — no numbers showing how strongly growth was slowed — so the size of the benefit is unknown, and PNLDC1 levels would first need to prove useful for selecting patients. This is bench research, not a clinical signal; for how benzimidazoles (the drug family mebendazole belongs to) are actually used and discussed, see our dosing calculator, the fenbendazole vs mebendazole comparison and the wider mebendazole mechanism research.
In plain words
What happened: Researchers tested mebendazole on colorectal cancer cells, patient-derived tumor clusters, and mice carrying human tumors, focusing on tumors with low PNLDC1.
Why it matters: Low PNLDC1 may remove a natural brake on a protein cancer cells use to divide. The study tested whether mebendazole could interrupt that growth pathway.
How strong is the evidence: The evidence is from cells, patient-derived clusters, and mice; no patients were treated. The size of the effect is not yet known.
What it means for you: Nothing changes in care today. These preclinical results do not show mebendazole helps people with colorectal cancer; discuss any drug use with your oncologist.
References
- Liu L, Guan Y, Qin Y, et al. ER-Localized Deadenylase PNLDC1 Suppresses Colorectal Cancer Progression by Targeting the mRNA Decay of TUBB4B. Exploration. 2026 Sep 21. doi:10.1002/exp2.70222. PMID: 42774471.
Medical Disclaimer
This article is for informational purposes only and is not medical advice. The study described is laboratory research in cells and animals, not a trial in patients. Never start, stop or change any medication without consulting a licensed healthcare provider.
Sanare Lab
Science-based health education team reviewing published research on repurposed drugs, integrative oncology, and evidence-based protocols.