Skin cancer: An introduction Prof JL Marnewick Prof WCA Gelderblom Institute of Biomedical and Microbial Biotechnology Cape Peninsula University of Technology marnewickj@cput.ac.za gelderblomw@cput.ac.za Panel members: Dr S Abel Dr M Lilly Dr T Magcwebeba Dr S Samodien Ms L Keet Rooibos Science Café 2 April 2019

INTRODUCTION The skin is our first line of defense! SKIN Skin largest organ 1.5-2 m2 Adult: ~3.6 kg of skin Different layers of the skin: Epidermis - Top/outer layer - Make new skin cells every month - Protecting the body (has immune cells) Dermis - Deeper layer - Making sweat to keep you cool - Help feel things (nerve endings) - Growing hair - Making oil - Bringing blood to the skin Fat layer - Attached dermis to muscles & bones - Help blood vessels & nerve cells - Control body temperature - Protects you from bumps & falls The skin is our first line of defense! INTRODUCTION

INTRODUCTION SUN Ultraviolet (UV) rays damage skin: UVA; UVB UVA: known as the “aging rays” it penetrates deeper skin layers, cause ageing, increased risk for cancer dominant ray used in tanning salons UVB: known as the “tanning rays”, cause sever damage to the epidermis redness, cancer- causing UVC: most dangerous, BUT completely filtered out by the ozone layer INTRODUCTION

INTRODUCTION Adverse effects of chronic exposure to the sun Induce oxidative stress DNA damage Premature ageing Effects immune system Skin disease Melanoma skin cancer Non-melanoma cancer, e.g. SCC (connected to tanning beds) Skin cancer STATS Most common cancer in SA Everyone is at risk WHO predicts increase in skin cancer as the ozone levels decrease 20 000 reported cases annually, 700 deaths 2nd highest incidence SA, Australia has highest incidence INTRODUCTION

Current prevention strategies: (also refer to recommendations by CANSA): Avoid sun exposure between 10am to 3pm Stay in the shade/under the umbrella Remember: UV reflects off cement/water/sand/grass – you can still burn Apply and re-apply your sunscreen often We can’t change the environment, but we can change our attitude towards the sun, by taking an additional prevention approach, that of Photo chemoprevention: a strategy in which the occurrence of skin cancer is reduced by using naturally occurring or synthetic compounds Use of to prevent or slow down the development of certain cancers is gaining popularity Plant components/polyphenol properties Anti-inflammatory Immune modulatory Redox modulation/Antioxidant Popular compounds to explore Rooibos and honeybush rich in polyphenols INTRODUCTION

INTRODUCTION Interesting facts: The International Agency for Research on Cancer (IARC) in France has classified UV-emitting tanning devices (such as sunbeds “carcinogenic to humans” and classified it as a class 1 carcinogen (2009) Australia has banned the use of sun beds in certain states of their country since the 1st of January 2015 The Cancer Association of South Africa (CANSA) has made a request to the Minister of Health to ban the use of sunbeds at least by our youth (<18yrs of age) INTRODUCTION

INTRODUCTION Treatment/Costs Most skin cancers found at an early stage can be treated successfully. Treatment depends on the type of skin cancer and the stage of the disease. Common Treatment for Skin Cancer: • Surgery • Various chemotherapies • Radiation • Biological drug treatments Other Possible Treatment: • Immunotherapy (for melanoma skin cancer) • Photodynamic therapy (for non-melanoma skin cancer) In 2015 alone, skin cancer cost the South African health system more than R90 million (more than US$6 million) - BMC Health Services Research Journal. INTRODUCTION

Fig. 1. The cellular composition of the skin Fig. 1. The cellular composition of the skin. Keratinocytes are a major source of IL-1. When activated and secreted, the cytokine induces an inflammatory response through activation and recruitment of immune cells (inspired from Nestle et al., 2009a).

Panel discussion Skin Cancer Chemoprevention South African Herbal Teas Panel members: Prof Wentzel Gelderblom (Chair - CPUT) Prof Jeanine Marnewick (CPUT) – co-chair Dr Stefan Abel (CPUT) Dr Mariska Lilly (CPUT) Dr Tandeka Magcwebeba (US - post doc) Dr Sedicka Samodien (CPUT – post doc) Ms L Keet (US - PhD candidate)   Panel discussion

Rooibos against cancer development in skin Inflammation Free radicals (oxidative stress) Cell growth Removes inflamed and damaged precancerous cells via programmed cell death

References References and information sheets Skin Cancer Fact Sheet (Prevention and Cancer Foundation) Fact Sheet – Skin Cancer 2010 (CANSA) Major findings: rooibos protects against adverse effects of UVB exposure. SARC media release; December 2016 (Prof WCA Gelderblom) SA children more at risk from sunburn at school due to inadequate sun protection policies. SARC media release; January 2017 (Dr T Magcwebeba) References