Dr Margaret Vissers
Dr Margret Vissers, from the Free Radical Research Group (University of Otago, Christchurch), in collaboration with the Angiogenesis Research Group, has recently shown that having enough intracellular vitamin C is essential for the maintenance of normal cell function. This work has recently been published in two papers detailing the vital role vitamin C plays in cell survival.
"What our results show is that vitamin C is part of a fundamental vital command-and-control mechanism in all cells in the body," she says. "This has never been shown before and in my view it is an exciting and major advance in understanding the key role of this vitamin in maintaining good health."
Vissers' work has illustrated the dependence of key enzymes on the presence of vitamin C. These enzymes are hydroxylases that control a transcription factor known as HIF-1, that turns on specific genes.
Many processes fundamental to cell survival, such as energy metabolism, stress responses, cell death and growth, are controlled by the HIF-1 transcription factor. When vitamin C is low or absent it appears that HIF-1 is turned on and the cells respond by changing the way they respond to stress.
And what does this mean for cancer?
"Well, cancer cells thrive when HIF-1 is turned on. This causes them to make more blood vessels, grow well and survive chemotherapy.
We think that when vitamin C is low or absent, the transcription factor HIF-1 is more readily turned on and this gives a survival advantage to the cancer.
It follows then that restoring vitamin C to normal levels could mean less tumour growth and more successful chemotherapy."
Vissers' next step is working with tumour tissue to test if it is actually low in vitamin C, with the possibility that boosting levels of this easily-accessible vitamin will make a difference to cancer treatment.
FUNDING
Health Research Council
University of Otago