Breast Cancer Therapy, Tamoxifen, May Promote Myelin Repair in MS

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remyelination and MS

Tamoxifen (brand name, Nolvadex), a widely used treatment for breast cancer, can also be used to treat myelin loss in patients with multiple sclerosis (MS), a new study suggests.

The finding, by a team of researchers at the University of Cambridge, U.K., was published in a study titled “Tamoxifen accelerates the repair of demyelinated lesions in the central nervous system” in the journal Scientific Reports.

Researchers used both  in vitro cultures and a mouse model with reduced levels of myelin to analyze how six existing drugs might effect the repair and recovery of cells able to produce myelin, called oligodendrocytes.

“We’re very excited about our findings,” said Mark R.N. Kotter, the study’s senior author, in a news release. “What we discovered was that Tamoxifen can enhance myelin repair in MS by encouraging the brain’s own stem cells to regenerate myelin.”

Stem cells are unspecialized cells that are capable of becoming any other type of cell in an appropriate environment. The team found that tamoxifen, which targets the estrogen receptors (ERα, ERβ, and GPR30) present in these cells, stimulated the stem cells to become oligodendrocytes, the brain cells responsible for producing myelin. Estrogen receptors play an important role in oligodendrocyte differentiation and in remyelination.

Investigators also observed that mice with reduced myelin levels, when treated with tamoxifen, had increased numbers of brain oligodendrocytes, showing that, in vivo (in a living organism), tamoxifen may well induce remyelination in the brain. Together, these results support the use of tamoxifen to help repair myelin loss, a hallmark of MS.

“Considerable efforts are currently being made to develop remyelination-enhancing drugs. The use of tamoxifen has several advantages over the development of new drugs. For example, it has an excellent safety profile that has undergone the test of time by exhaustive application in the clinic,” the researchers wrote.

The team believes that tamoxifen is a good candidate for future clinical trials that will assess its potential ability to effect myelin repair in people with MS.

Myelin loss occurs in several neurological disorders. In the most prominent demyelinating disease, MS, myelin sheaths in neurons are damaged by an autoimmune process.

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  1. miked says:

    Was anything said about the side effects of Tamoxifen. It’s use in women with breast cancer is to stop the production of estrogen for those patients with estrogen sensitive breast cancers.

  2. Tom says:

    Can anyone comment about this article, the studies, and whether individuals that have had myelin damaged by Guillain Barre Syndrome may benefit?

    • Judy Kerfoot says:

      I was diagnosed with MS In 2004 and breast cancer in 2009. I took Tamoxifen for 6 years. I have always been on a MS medication since my diagnosis with a very slow decline. Since being taken off Tamoxifen 10 months ago due to a blood clot, my symptoms have been increasing at a faster rate with several new symptoms.

  3. Candyce Rogers says:

    I was first diagnosed with breast cancer 11 years ago and then again 5 years ago in the other breast I have been on Tamoxifen for 10 years and was diagnosed with MS just last November but my neurologist told my my most recent mri shows that my lesions are now calm and my disease is pretty much under control maybe there is a correlation.

  4. spiro says:

    My comment is to exercise caution in interpreting these early pre-clinical findings. Let’s look at what happened to anti-LINGO, a drug that showed remyelination potential in vivo but failed to translate to anything significant in humans other than better visual evoked potentials. Also, this drug is at least ten years out before all the required clinical trials are done and that’s assuming it even does anything. Until we understand that MS is not just a demyelinating disease but also primarily a disease of axonal loss, disability will not be repaired. Sorry for sounding so jaded but I’m tired with the lack of focus and the word “hope” that we always hear while we progress intractably.

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