UK Researchers Find How to Prevent Hair Loss from Chemotherapy

Researchers from the UK's University of Manchester have discovered a drug which appears to prevent hair loss from chemotherapy.

This huge breakthrough was made by investigating the applications of the CDK4/6 inhibitor palbociclib to organ-cultured scalp hair follicles which were subjected to taxane chemo.

Taxanes are a type of cancer treatment drug used in chemotherapy and which are, according to the study, "a leading cause of severe and often permanent chemotherapy‐induced alopecia".

This potentially groundbreaking discovery could mean the end of both temporary and permanent hair loss for cancer patients undergoing taxane chemotherapy.

Awareness of this particular suite of chemo drugs has increased over the past few years thanks to lawsuits in the USA brought by former Taxotere patients who experienced chemo-induced alopecia. The claim is based upon their not being warned about the risk of the drug causing permanent baldness.

Preventing taxane-induced damage to hair follicles

Hair loss from chemotherapy is known as Anagen Effluvium; it only affects the hairs that are in the active Anagen stage of the hair growth cycle when starting chemo.

Belgravia superintendent trichologist, Rali Bozhinova explains, "Anagen Effluvium can sometimes cause all anagen hairs to fall out; as this is approximately 90 per cent of all of scalp hair, it leaves the patient looking bald. However, unlike with many other hair loss conditions, this shedding is caused by hair snapping off, rather than falling out from the bulb. This is why, in many cases - where the follicle is not damaged - normal hair regrowth is possible."

The University of Manchester's report, published on 12th September 2019 in the EMBO Molecular Medicine journal, explains how, when this hairloss is caused by taxanes, it is due to their toxicity to the dividing stem cells and the transit amplifying cells located in the hair follicle.

The team discovered that a CDK4/6 inhibitor known as palbociclib can both block cell division and antagonise taxane‐induced damage in the hair follicle. Continues below...

The two key taxane drugs investigated were paclitaxel and docetaxel which are used to treat a number of common cancers, including breast, lung, ovarian and cervical cancer. The Manchester team advises these are known to "promote mitotic defects and apoptosis in proliferating hair follicle stem/progenitor and transit amplifying cell compartments".

Essentially this means taxanes can encourage problems in cell division and the death of cells that are crucial to an organ's growth.

Having created an ex-vivo human hair follicle organ culture system, researchers tested their taxane-induced damage theories and were able to show precisely how the drugs impaired stem, progenitor and transit amplifying cell niches.

They advised of their findings: "Paclitaxel and docetaxel induced massive mitotic defects and apoptosis in transit amplifying hair matrix keratinocytes and within epithelial stem/progenitor cell‐rich outer root sheath compartments, including within Keratin 15 cell populations, thus implicating direct damage to stem/progenitor cells as an explanation for the severity and permanence of taxane chemotherapy‐induced alopecia."

"We show that the G1 arresting CDK4/6 inhibitor palbociclib antagonises the mitosis‐targeting cytotoxicity of taxane chemotherapy in stem cell and transit amplifying cell compartments in the human hair follicle, without promoting premature catagen (i.e. hair growth arrest) or additional hair follicle toxicity."

Therefore, not only have the researchers found a way to prevent hair loss from chemotherapy that involves this suite of drugs, they have also uncovered information about the pathobiology of taxane treatments in relation to hair follicles, which should be extremely useful to oncologists.

"Scratching the surface"

Lead study author and research assistant in the University of Manchester's Division of Musculoskeletal & Dermatological Sciences, Dr Talveen Purba spoke about the importance of the team's revelations in a press release, but was keen to stress this was just the start...

“Although at first this seems counter-intuitive, we found that CDK4/6 inhibitors can be used temporarily to halt cell division without promoting additional toxic effects in the hair follicle,” he said.

“When we bathed organ-cultured human scalp hair follicles in CDK4/6 inhibitors, the hair follicles were much less susceptible to the damaging effects of taxanes... Despite the fact that taxanes have been used in the clinic for decades, and have long been known to cause hair loss, we’re only now scratching the surface of how they damage the human hair follicle.

We found that the specialised dividing cells at the base of the hair follicle that are critical for producing hair itself, and the stem cells from which they arise, are most vulnerable to taxanes. Therefore, we must protect these cells most from undesired chemotherapy effects - but so that the cancer does not profit from it,” he concluded.

In addition to furthering this research - presumably into product development in order to provide cancer patients with safe and effective hair retention options other than scalp cooling systems - future studies may expand upon why certain people experience more hair loss from taxanes than others.