New Drug Temporarily Tans Skin on Mice. Sun Exposure for Tanning Not Needed in Near Future.

Many spend time lying on the beach or beside the pool exposing skin to the sun in the summer to get the perfect tan. This time spent outside increases the risk of harmful ultraviolet (UV) rays mutating your DNA; but now scientists have developed a new drug that gives you a suntan without even having to go outside or spend time in a tanning bed.

While it may seem strange that scientists are putting effort into something superficial like getting a tan, the need for a replacement to UV exposure is real. In fact, over the past three decades more people in the US have suffered from skin cancer than any other cancer combined, and 90% of the nonmelanoma cases are associated with exposure to UV radiation from the sun.

Source: Cast Pharma via YouTube

Researchers at the Massachusetts General Hospital and Dana-Farber Cancer Institute developed a new way to increase skin pigmentation as reported in the June 13 issue of Cell Reports. This study is a follow-up to a 2006 study that discovered the molecular pathways underlying the tanning response and induced tanning in a strain of mouse that does not produce the protective, dark pigment, melanin. Both studies were led by Dr. David E. Fisher, chief of the Dermatology Department at Mass. General.

The initial results from mice were promising, but when tested on humans, the team ran into the problem of skin thickness. Mice have five times thinner skin than humans so it was easier for the topical drug to penetrate all layers. The solution was to repress enzymes called salt-inducible kinases (SIKs) known to regulate the microphthalmia-associated transcription factor (MITF) gene. The scientists working on this discovery “hypothesized that small-molecule SIK inhibitors could be generated and optimized as topical agents capable of inducing cutaneous pigmentation independently of UV irradiation in human skin” by inducing MITF signaling.

Microsoft Word - Figures 05052017.docx
Source: Cell Reports
(A) mRNA expression of MITF relative to RPL11 mRNA and vehicle control in normal human melanocytes 3 hr after HG 9-91-01 or vehicle control (70% ethanol, 30% propylene glycol) treatment, quantified by qRT-PCR (n = 3, mean ± SEM).
(B and C) mRNA expression of MITF (B) and MITF-dependent gene TRPM1 (C) relative to RPL11 mRNA and vehicle control at each time point, in normal human melanocytes over 24 hr after 4 μM HG 9-91-01 or vehicle control treatment, quantified by qRT-PCR (n = 3, mean ± SEM).
(D) Cell pellets of UACC257 melanoma cells after 3 days of treatment with vehicle control or 4 μM SIK inhibitor HG 9-91-01 (image is representative of n = 3 experiments).

Inhibition of SIK by HG 9-91-01 Promotes MITF Transcription and Pigmentation In Vitro

By inhibiting SIKs in mice, researchers were able to create the same skin darkening results on the same fair haired strain of mice as in 2006. Small-Molecule inhibition of SIK induced MITF expression on skin samples providing encouraging results for the drug’s ability to penetrate human epidermis.

The drug (HG 9-91-01) is applied topically to stimulate the melanin process as demonstrated by the mice and skin samples.

“We are excited about the possibility of inducing dark pigment production in human skin without a need for either systemic exposure to a drug or UV exposure to the skin,” says Fisher.

Having a drug to produce the effects of UV rays would create a healthy alternative for skin. Though a drug is far from  being produced, initial results are encouraging for scientists to dig deeper. No matter what you may hear at tanning salons, the cumulative damage caused by UV radiation can lead to premature skin aging (wrinkles, lax skin, brown spots, and more). Just using a tanning bed before age 35 increases the risk for melanoma by 75 percent! For now use sunscreen, limit sun exposure, and keep your eye out for more results on this tanning alternative.

cover photo: Women’s Fitness

Leave a Reply

Up ↑