A plant native to one of the world’s largest jungles could hold the key to combating deadly pancreatic cancer, according to new research.
Experiments found the vine Ancistrocladus likoko destroys cancer cells – and stops them spreading.
It only grows in the Congo, the second largest rainforest behind the Amazon covering almost 800,000 square miles across Central Africa.
Natural medicine experts have discovered the plant contains a chemical that combats the tumour’s remarkable ability to survive.
Pancreatic cancer is the most lethal common cancer in the UK. Three quarters of patients die within a year of diagnosis.
This is due to it thriving under extreme conditions of low nutrients and oxygen, a trait oncologists call “austerity.”
Now the Japanese team have found the compound has strong “anti-austerity” properties – making the tumour cells vulnerable to starvation for the first time.
They extracted molecules from ground twigs and separated them using a scanning technique called high-performance liquid chromatography.
Then they developed a drug based on the alkaloid – which are chemical compounds produced by plants.
Professor Suresh Awale, of the University of Toyama, said: “The new alkaloid is a promising compound for anti-cancer drug development based on the anti-austerity strategy.”
The study published in the Journal of Natural Products said pancreatic cancer has a five year survival rate of less than five percent.
The tumour cells proliferate so aggressively they deplete nutrients and oxygen in the surrounding area.
Most cells would die in such a harsh environment. But pancreatic cancer survive by activating a chemical called Akt/mTOR.
Testing plants for anti-austerity compounds that block this process is of increasing interest to pancreatic cancer researchers.
Prof Awale and colleagues previously identified some unusual alkaloid compounds with this potential from vines found in the Congolese rainforest.
Now they have gone a step further by characterising the 3D structure of the Ancistrocladus likoko alkaloid from twigs.
Named ancistrolikokine E3, they found it killed pancreatic cancer cells under conditions of starvation.
But this did not happen when nutrients were plentiful – meaning it should not be harmful to healthy cells.
The drug also inhibited spread and colonisation in tumour cells grown in the lab – suggesting it could help stop the disease in its tracks in patients. This was due to it inhibiting Akt/mTOR.
Prof Awale said: “Human pancreatic cancer cells are characterised by their ability to proliferate aggressively in the tumour microenvironment, displaying a remarkable tolerance to nutrition starvation.
“The antiausterity strategy is a new approach in anticancer drug discovery aiming at the identification of potent agents that inhibit preferentially the survival of tumour cells during a limited supply of nutrients and oxygen.”
“The new alkaloid ancistrolikokine E3, isolated from the Congolese vine Ancistrocladus likoko, showed potent preferential toxicity against pancreatic cancer cells under nutrient-deprived conditions.
“The compound was found to induce dramatic alterations in cell morphology, leading to cell death.
“Moreover, it inhibited significantly pancreatic cancer cell migration and colony formation.”
He added: “This study provides the first live evidence of the effect of an alkaloid against pancreatic cancer cells.”
Earlier this week a report revealed the number of deaths from pancreatic cancer has almost doubled in the past three decades.
It now kills more than 95,000 people in Europe each year – making it the continent’s “deadliest” form of the disease.
It kills more than 9,000 people a year in the UK alone. It has the lowest average survival time after diagnosis of all cancers – just four-and-a-half months.
Known as ‘the silent killer’, symptoms are hard to identify – making it difficult to catch early when life-saving surgery can be carried out.
by Mark Waghorn