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How toxic fungus in Tutankhamun's tomb can help fight cancer
A deadly fungus behind the so-called curse of Tutankhamun 's tomb can be harnessed to fight cancer, scientists have discovered.
Aspergillus flavus, a toxic fungus linked to deaths in the excavations of ancient tombs, can be transformed into a potent cancer-fighting compound, they found.
Researchers at Penn University, Pennsylvania, believe it opens up new frontiers in the discovery of more fungal medicines.
The mould, named for its yellow spores and long considered a microbial villain, has been found growing in sealed tombs in Egypt and was thought to be responsible for the deaths of several people who entered, including Tutankhamun's in 1923.
Aspergillus spores grow especially well on grain, the supply of which was abundant in Tutankhamun's tomb, with offerings of bread and raw grain stored in numerous baskets.
From curse to cure
The idea of a pharaoh's curse had endured from the 1820s, with the discovery of dire warnings on the walls of tombs intended to deter robbers.
After Tutankhamun's tomb was opened, there followed a series of deaths of those among the excavation team, including expedition patron Lord Carnarvon, financier George Jay Gould and Egyptologist Arthur Mace, giving fuel to the idea of a curse.
Decades later, doctors theorised that fungal spores, dormant for millennia, could have played a role.
In the 1970s, a dozen scientists entered the tomb of Casimir IV in Poland. Within weeks, 10 of them died. Later investigations revealed the tomb contained A. flavus, the toxins of which can lead to lung infections, especially in people with compromised immune systems.
The mummy of Ramses II was taken to Paris in 1976 and 89 species of fungi were isolated from it, including aspergillus.
Now, that same fungus is the unlikely source of a promising new cancer therapy.
'Fungi gave us penicillin,' said Sherry Gao, of Penn University, senior author of a new paper in Nature Chemical Biology on the findings. 'These results show that many more medicines derived from natural products remain to be found.'
Pharaoh's curse
British aristocrat Lord Carnarvon, who funded the expedition to find the Tutankhamun tomb, died in a Cairo hotel four months after the crypt was opened.
He had been in poor health for many years after a car crash, and a mosquito bite made worse by a shaving cut led to blood poisoning and pneumonia.
Reports at the time said Lord Carnarvon suffered from 'pain as the inflammation affected the nasal passages and eyes'.
Decades later, scientists contended he had died of aspergillosis after inhaling spores of the fungus aspergillus in the tomb, which can lie dormant for months. The fact several others who entered were also found dead withiin a short time led to the myth of the curse.
Hunting for chemicals
The researchers scanned a dozen strains of Aspergillus, to find promising candidates that may lead to a medicine.
They found identified could be modified to create cancer-fighting molecules called asperigimycins.
Even with no modification, when mixed with human cancer cells, asperigimycins demonstrated medical potential against leukaemia cells.
Another variant, to which the researchers added a fatty molecule found in the royal jelly that nourishes developing bees, performed as well as two drugs that have been used for decades to treat leukaemia.
Disrupting cell division
Through further experimentation, the researchers found that asperigimycins can disrupt the process of cell division. 'Cancer cells divide uncontrollably,' said Ms Gao. 'These compounds block the formation of microtubules, which are essential for cell division.'
The compounds appeared to have a specific effect on leukaemia cells but had little to no effect on breast, liver or lung cancer cells.
Qiuyue Nie, a postdoctoral fellow and the paper's first author, said the compounds had 'strong bioactivity'. 'This is an unexplored region with tremendous potential,' she added.
The next step is to test asperigimycins in animal models, with the hope of one day moving to human clinical trials. 'Nature has given us this incredible pharmacy,' said Ms Gao. 'It's up to us to uncover its secrets. As engineers, we're excited to keep exploring, learning from nature and using that knowledge to design better solutions.'
