UJ team discovers silver lining in the dark clouds of cancer

28 March 2018 - 08:56 By Hannah Green
Head of Department, Prof Marianne Cronjé- Department of Biochemistry.
Head of Department, Prof Marianne Cronjé- Department of Biochemistry.
Image: Department of Biochemistry, UJ

Researchers at the University of Johannesburg may have come up with a silver bullet for certain cancers.

Laboratory tests suggest a newly discovered family of silver-based anti-cancer drugs could provide smaller dosages‚ lower toxicity and fewer adverse side-effects.

The most promising is a potential drug for breast cancer‚ melanoma and oesophageal cancer that they call UJ3 – otherwise known as a silver thiocyanate phosphine complex. Tests on cells suggest it is as effective as commercial drugs on the market today.

But it requires a 10 times lower dosage to kill cancer cells than the current industry standard. This‚ say the researchers‚ reduces patients’ chance of experiencing adverse side effects. And in terms of toxicity‚ UJ3 is about as dangerous as your morning cup of orange juice.

“In rat studies‚ we see that up to 3 grams of UJ3 can be tolerated per kilogram of bodyweight. This makes UJ3 and other silver phosphine complexes we have tested about as toxic as vitamin C‚” said Professor Reinout Meijboom‚ UJ’s head of chemistry.

The danger of cancer cells lies in their ability to reproduce indefinitely‚ relying on the cell’s own mitochondria to support their uninhibited growth.

The study found that UJ3 specifically targets the mitochondria of cancer cells‚ leaving healthy cells untouched. In a process known as apoptosis‚ UJ3 shuts down a cancerous cell’s mitochondria and triggers the release of an “executioner” protein‚ which disables and dismembers the cell safely for recycling within the body.

The researchers said the properties of silver make UJ3 and its relatives more reproducible than current industry drugs.

“These complexes can be synthesised with standard laboratory equipment‚ which shows good potential for large scale manufacture‚” said Meijboom.

This research is a part of a 10-year project by Meijboom and biochemistry professor Marianne Cronjé.