Nature communications report on further evidence to explain why tumours convert significantly higher amounts of sugar into lactate compared to healthy tissues, otherwise known as the Warburg effect.
Scientists from The Flanders Institute for Biotechnology believe they may have answered the question as to whether the effect is a symptom of cancer or a cause.
“Our research reveals how the hyperactive sugar consumption of cancerous cells leads to a vicious cycle of continued stimulation of cancer development and growth,” explained Professor Johan Thevelein, co-lead study author from the University of Leuven.
“Thus, it is able to explain the correlation between the strength of the Warburg effect and tumour aggressiveness.”
The nine-year joint research project conducted by the two institutions provides a new direction for an extensively studied area.
As well as providing guidance for a more beneficial diet for cancer patients, the general population could well take heed of one more piece of evidence about the dangers of excessive sugar consumption.
Sugar and the food industry
For the food industry, attempts at self-regulation have not been the expected success. So much so that Governments have had to step in to impose various levies in an attempt to curb excess sugar consumption.
The UK will introduce its soft drinks industry levy in April 2018, with drinks that have a total sugar content of 5g or more per 100ml levied at €0.20 (£0.18) per litre. Those with 8g or more per 100ml will be set at €0.27 (£0.24) per litre.
Public Health England (PHE) advise chocolate to contain 43.7g of sugar per 100g by 2020 in voluntary health guidelines released earlier this year in efforts to cut sugar by at least 20%.
Chocolate confectionery on sale in the UK currently has an average portion size of 44 g and contains an average sugar content of 54.6 g per 100 g with 197 calories per portion, according to PHE.
Along with Dr Wim Versées and Veerle Janssens, Professor Thevelein chose to use yeast cells in their research as they contained the same 'Ras' proteins commonly found in tumour cells.
The research team then examined the connection between Ras activity and the highly active sugar metabolism in yeast.
By observing how sugar is degraded in yeast, the tem were able to identify the intermediate fructose 1,6-biophosphate’s role in the activation of Ras proteins.
These proteins then went on to stimulate the multiplication of both yeast and cancer cells.
“It is striking that this mechanism has been conserved throughout the long evolution of yeast cell to human,” said Professor Thevelein.
"The main advantage of using yeast was that our research was not affected by the additional regulatory mechanisms of mammalian cells, which conceal crucial underlying processes,” he added.
“We were thus able to target this process in yeast cells and confirm its presence in mammalian cells. However, the findings are not sufficient to identify the primary cause of the Warburg effect.
“Further research is needed to find out whether this primary cause is also conserved in yeast cells."
Source: Nature Communications
Published online ahead of print: doi:10.1038/s41467-017-01019-z
“Fructose-1,6-bisphosphate couples glycolytic flux to activation of Ras”
Authors: Johan Thevelein et al.