Improves cancer targeting a million‑fold
- University of British Columbia and BC Cancer researchers reported on April 28 that new compounds can hit the androgen receptor’s disordered cancer-driving region far better. - The standout claim is binding up to a million times tighter than earlier molecules, with prostate-cancer xenograft results beating enzalutamide in androgen-rich settings. - It matters because this region helps tumors evade standard hormone drugs, so better binders could open a new route after resistance.
Prostate cancer drugs usually go after a neat, folded pocket on the androgen receptor. That works — until the cancer finds ways around it. The hard part is the receptor’s floppy front end, a shapeshifting stretch that keeps driving tumor growth and has long looked basically undruggable. This week, a UBC and BC Cancer team said they’ve pushed much further into that problem, with compounds that bind this disordered region up to a million times more tightly than anything previously reported. (med.ubc.ca) ### What is the actual target here? The target is the androgen receptor, the master switch that fuels most prostate cancers. Existing drugs like enzalutamide hit the receptor’s ligand-binding domain — the more structured part near one end. But advanced tumors often reactivate androgen receptor signaling anyway, including through splice variants such as AR-(med.ubc.ca) (nature.com) ### Why has that region been so hard to drug? Because it does not hold still. Most drug discovery depends on finding a stable pocket — a lock you can design a key for. Intrinsically disordered regions are not like that. They shift shape as they interact with other molecules, so the target is moving while you aim at it. That is why these proteins have been labeled “undruggable” for years, even though they sit at the center of cancer and other diseases. (med.ubc.ca) ### What changed this week? The new paper, published April 28 in *Signal Transduction and Targeted Therapy*, describes a refined set of AR-TAD inhibitors — ARTADIs — from Marianne Sadar’s group and collaborators. The team says some of these compounds reached picomolar to low-nanomolar binding strength, which put them better than, or comparable to, enzaluta(med.ubc.ca) for disordered proteins. (nature.com) ### What does “million-fold tighter” really mean? Basically, affinity is a measure of how strongly a drug latches onto its target. A million-fold jump is not a small optimization — it is the difference between a weak grip and something much more like a clamp. The catch is that “tighter binding” is not the same thing as “proven medicine.” It means the chemistry got dramatically better at engaging the target, which is the first gate any useful drug has to pass. (med.ubc.ca) ### Did it work in cancer models? Yes, in preclinical models. The paper says these ARTADIs outperformed enzalutamide in prostate cancer xenografts when androgens were present. That matters because androgen-rich conditions are exactly where the receptor is supposed to be dangerous. The compounds also disrupted interactions involving both full-length androgen receptor and the splice-variant form AR-V7, which is one of the nastier resistance routes in advanced disease. (nature.com) ### Is this the first time this group has done this? No — and that is part of why people are paying attention. Sadar’s team says it developed the first compound able to bind these disordered androgen-receptor regions back in 2008, and UBC says two related drugs have already advanced into clinical trials. So this is not a one-off curiosity. It looks more like a long program finally getting much better chemistry. (med.ubc.ca)million-fold-leap-in-targeting-elusive-cancer-proteins/)) ### What is still missing? Human proof. These are still preclinical results, and disordered targets are tricky partly because binding, selectivity, and downstream biology can all shift together. Even the paper frames the work as proof that this kind of target is druggable — not proof that a finished therapy is ready. Safety, durability, and whether these compounds keep their edge in patients are still open questions. (nature.com) ### Bottom line? This is a real drug-discovery story, not just a flashy number. The advance is that researchers seem to have gotten a much firmer handle on the androgen receptor’s most evasive region — the part prostate cancer uses to escape standard therapy. If that chemistry holds up, it could turn one of oncology’s most stubborn “moving targets” into a practical place to attack. (med.ubc.ca)-elusive-cancer-proteins/))
