Vitamin K supplement slows prostate cancer cells, study finds

Researchers have long explored ways to prevent and treat prostate cancer, one of the most common cancers in men. For years, many believed antioxidants like vitamin E could stop or slow cancer. But after a massive trial showed vitamin E might actually increase cancer risk, scientists started looking in the opposite direction.

At Cold Spring Harbor Laboratory, a new approach is gaining traction. Instead of blocking oxidation with antioxidants, researchers are now boosting it with a compound called menadione. This water-soluble vitamin K precursor, often found in leafy greens, may hold the key to slowing prostate cancer and treating a rare genetic muscle disorder.

In 2001, the National Cancer Institute launched one of the largest cancer prevention trials in history. Known as the SELECT trial, it followed more than 35,000 healthy men for over a decade to test whether antioxidants—specifically selenium and vitamin E—could prevent prostate cancer. By year three, researchers shut down part of the study. Vitamin E hadn’t helped. In fact, men taking the supplement were more likely to develop prostate cancer.

That shocking result led Cold Spring Harbor Laboratory’s Lloyd Trotman to rethink the entire theory behind antioxidants. If antioxidants increased risk, he asked, could pro-oxidants decrease it?

Working with a genetically engineered mouse model of prostate cancer called RapidCaP, Trotman’s lab decided to test that idea. This model mimics the way cancer develops and spreads in humans, letting researchers track how fast tumors grow or become dangerous.

They gave the mice menadione sodium bisulfite, a precursor of vitamin K that acts as a pro-oxidant. Unlike antioxidants, which protect cells from damage caused by unstable molecules known as free radicals, pro-oxidants promote that damage. In cancer cells, this can disrupt survival.

The result was striking. Mice treated with menadione saw their cancer slow down. But the team wanted to know why.

Trotman’s group dug into the molecular changes caused by menadione and found something unexpected. The compound targets a molecule called PI(3)P, a type of lipid that helps cells organize and recycle materials. This molecule is produced by the enzyme VPS34, also known as phosphatidylinositol 3-kinase catalytic subunit type 3.

By reducing PI(3)P levels, menadione prevents cancer cells from keeping track of what enters their internal transport systems. Without this guidance, their recycling process breaks down. The cells start filling up with waste, causing them to swell and eventually burst.

“It’s like a transport hub, like JFK,” says Trotman. “If everything that goes in is immediately de-identified, nobody knows where the airplanes should go next. New stuff keeps coming in, and the hub starts to swell. This ultimately leads to the cell bursting.”

This process appears to halt the cancer’s progression, giving scientists hope that menadione could someday slow the disease in humans as well.

Trotman says the next step would be testing menadione in early-stage prostate cancer patients—those who’ve just been diagnosed through a biopsy but haven’t started treatment. “We wonder if they start to take the supplement, whether we would be able to slow that disease down.”

While investigating menadione’s mechanism, the team noticed something intriguing. VPS34 activity isn’t only important in cancer. It’s also linked to a rare genetic muscle disorder known as X-linked myotubular myopathy. This condition affects infant boys and stops muscles from developing properly. Most children diagnosed don’t survive beyond early childhood.

This muscle disease is caused by a lack of myotubularin, an enzyme that acts as a brake on VPS34. Without this brake, VPS34 runs unchecked, flooding cells with PI(3)P and disturbing their balance. Trotman’s group realized that if menadione could block VPS34, it might restore balance in cells affected by the muscle disorder.

When they tested this idea in mice with the disease, the results were promising. Menadione supplementation doubled the animals’ lifespan.

While these findings are still early, they suggest that a single compound could benefit two very different patient groups—men with prostate cancer and boys with a rare muscle condition. That kind of cross-disease effectiveness is rare in medicine, and it’s one reason researchers are excited.

Prostate cancer is diagnosed in hundreds of thousands of men each year. In most cases, it grows slowly and responds well to treatment. But for some, the disease becomes aggressive and resists all current therapies. That’s when it turns deadly.

New strategies that delay or stop this shift could save lives. That’s why Trotman’s team believes menadione deserves more attention. It’s already found in some foods and used as a dietary supplement in other forms. Its safety profile is relatively well-known, which could speed up human trials.

This work also pushes scientists to rethink what they thought they knew about supplements. The idea that antioxidants always help and oxidative stress always harms no longer holds up. In fact, promoting a little stress inside the right cells—like cancer cells—may be exactly what’s needed to shut them down.

The SELECT trial, which once seemed like a setback, may have sparked a new direction in cancer therapy. Trotman and his colleagues have turned a failed antioxidant study into a launchpad for a promising pro-oxidant approach. With further research and testing, menadione could become part of future treatment plans, not just for cancer, but for rare genetic diseases as well.

There’s still much work to do. The findings in mice need to be repeated in humans. Dosage, timing, and safety all require careful study. But the early results are hopeful.

Trotman’s team envisions a day when men diagnosed with early-stage prostate cancer could take a simple supplement to slow the disease. Families of children with myotubular myopathy might get more time with their loved ones. A humble compound derived from leafy greens may offer new hope in two very different medical battles.

As science continues to question old assumptions and test new ideas, the future of cancer and genetic disease treatment grows a little brighter.

Research findings are available online in the journal Science.

Note: The article above provided above by The Brighter Side of News.

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