Emerging researchers working to effectively treat skin cancer

South Africa experiences one of the highest rates of skin cancer globally, with 20 000 new skin cancer cases and 700 related deaths annually, according to the Skin Cancer Foundation of South Africa. Melanoma skin cancer is one of the most aggressive and treatment-resistant cancers and while it accounts for only 1% of skin cancers it is responsible for 80% of skin cancer deaths. Furthermore, it accounts for only 1.7% of all cancers diagnosed, but 20% of overall global deaths from cancer.

In the wake of SunSmart Skin Cancer Awareness Month and World Cancer Day we focus on the work of two young researchers: Dr Mohsin Khan of the Division of Cell Biology and PhD candidate, Suzanne Magagoum in the Medical Biotechnology and Immunotherapy Research Unit. Both are working on early-stage, proof-of-concept research to develop innovative targeted treatments to fight this scourge.

Repurposing commercially available drugs for the targeted treatment of melanoma

Getting a new drug to the market is a lengthy, costly and challenging process, and often not successful. But many of the existing commercially available drugs have unexplored potential and may be effective in the fight against melanoma. Dr Khan, working under the supervision of Professor Sharon Prince in the Department of Human Biology, in collaboration with the Goding Laboratory based at the Ludwig Cancer Research Centre at the University of Oxford, made use of a library of available drugs to test if any show potential to stop melanoma from spreading.

 

This has the advantage of speeding up the process of getting potentially life-saving drugs to those who need them

“Two key proteins in melanoma, TBX2 and TBX3, are responsible for the highly aggressive nature of melanoma,” said Khan. “We have screened already approved drugs to test if any, can stop these proteins.”

“This has the advantage of speeding up the process of getting potentially life-saving drugs to those who need them.”

Through this work Khan and colleagues discovered three promising drugs that inhibit these proteins and to selectively kill melanoma cells. Two of the three are traditionally used to treat parasitic worms and the third is an anti-fungal agent.

Using protein engineering to develop Immunotherapeutics of melanoma

Treating melanoma with chemotherapy is very challenging.
 

Chemotherapy does not only kill cancer cells, but also healthy cells, taking a significant toll on the health of the patient

“Chemotherapy does not only kill cancer cells, but also healthy cells, taking a significant toll on the health of the patient,” said Magagoum.

A further challenge however is that advanced or metastatic melanoma is often resistant to current treatments, making the treatment highly destructive without the desired effect.

Magagoum’s PhD research, undertaken under the supervision of Professor Stefan Barth within the Institute of Infectious Disease and Molecular Medicine, investigates the efficacy of three targeted treatments which attack a specific protein found overexpressed on melanoma cells (melanotransferrin). Since melanotransferrin contributes to the growth and chemoresistance in melanoma, it is a promising target in the development of effective immunotherapies for melanoma.

“The value of this potential treatment is its direct elimination of selected tumour cells, characterised by their overexpression of melanotransferrin, without harming normal cells,” said Professor Barth, “potentially leading to a targeted and more effective treatment for melanoma.”

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