Jumbo solution to cancer

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Sri Lanka’s most sacred animal could hold the key to curing cancer. With an army of tumour-fighting proteins in their genes, elephants may at last help us defeat the deadly disease.

The tumour-fighting proteins they carry can destroy mutated cells, say scientists, which could explain why Earth’s largest land animals are over five times less likely to develop cancer than humans.

According to new research, harnessing the elephant’s genes could lead to a ‘one-size-fits-all’ therapy for one of the world’s biggest killers.

“This intricate and intriguing study demonstrates how much more there is to elephants than impressive size and how important it is that we not only conserve but also study these signature animals in minute detail,” said the study’s co-author Professor Fritz Vollrath, of the University of Oxford. “After all, their genetics and physiology are all driven by evolutionary history as well as today’s ecology, diet and behaviour,” he added.

Despite their five ton bodies and longevity, elephants exhibit high resistance to cancer with less than five per cent mortality compared to up to 25 per cent for humans.

It’s a phenomenon that has puzzled biologists for decades as large creatures should be at greater risk for cancer as cells keep dividing throughout an organism’s life, each carrying the risk of producing a tumour.

But elephants inherit 40 versions of a gene called P53, 20 from each parent. Dubbed the ‘guardian of the genome’, it hunts down and kills cells with faulty DNA.

All other mammals have just two of this tough gene – one from each parent.

Biochemical analysis and computer simulations also showed the 40 versions in elephants are structurally slightly different, providing a much wider range of anti-cancer activity.

“This is an exciting development for our understanding of how p53 contributes to preventing cancer development,” said another co-author Professor Robin Fahraeus, of the French National Institute of Health and Medical Research.

“In humans, the same p53 protein is responsible for deciding if cells should stop proliferating or go into apoptosis (suicide) but how p53 makes this decision has been difficult to elucidate. The existence of several p53 forms in elephants with different capacities to interact offers an exciting new approach to shed new light on tumour suppressor activity.”

The findings published in the journal Molecular Biology and Evolution shed fresh light on how p53 proteins get activated.

These proteins open the door to developing medications that can increase its sensitivity and response against cancer causing environments. The researchers are now looking into activating p53 and targeted drug therapies in humans.

Why have humans not evolved this variegated gang of anti-cancer proteins, or indeed the different suite of cellular protections enjoyed by blue whales, if they would confer such a clear-cut survival benefit?

Scientists say more research is needed and there is real potential for a breakthrough. Research first reported in 2016 revealed that genetically engineering mice to have a few extra copies of p53 enhanced their cells’ ability to detect and repair DNA damage. This latest work suggests something many organisations are belatedly finding out: Success comes not just with a bigger team, but a more diverse one.

Elephants, prized for their ivory tusks, are critically endangered after being driven to the brink of extinction by poachers. Their numbers have experienced a significant decline over the last century with only about 400,000 left in Africa, and an estimated 30,000 in Asia.

A century ago, they were common across both continents.

Elephants also face added threats from global warming, habitat loss and conflict with humans – a particular problem in Sri Lanka.

For example, 49 elephants were killed in the Polonnaruwa District between 1 January and 30 June 2022. During the same period 17 people also died due to the human-elephant conflict.

Sri Lankan Wildlife Department officials pointed out that the deaths of both humans and elephants had increased significantly compared to the first six months of last year. 36 elephants were killed in the District between 1 January and 30 June 2021. 9 humans were killed by elephants in the same period.

Most of the elephant deaths were caused by illegal and unauthorised human activity – which sadly seems to be on the increase in Sri Lanka – even though there is now another reason to preserve these precious pachyderms.

By Michael Gregson