Investigators at the University of Alberta have recently reported that the drug DCA is able to cause tumor regression in a number of human cancers growing in animals.

The drug, dichloroacetate (DCA), is being used for years to treat rare metabolic disorders and is known to be relatively safe. It is also not protected by patents and hence could be made very cheaply, much cheaper than normal anti-cancer drugs.

The best part is that DCA (dichloroacetate) actually makes the cancer cells healthy by reactivating their mitochondria, their main power generator, which in turn makes cancer cells mortal like the other cells. The drug doesn't affect the normal cells of the body.

Evangelos Michelakis of the University of Alberta in Edmonton, Canada, and his colleagues tested DCA on human cells cultured outside the body and found that it killed lung, breast and brain cancer cells, but not healthy cells. Tumours in rats deliberately infected with human cancer also shrank drastically when they were fed DCA-laced water for several weeks.

DCA attacks an unique feature of cancer cells: the fact that they make their energy throughout the main body of the cell, rather than in mitochondria as is in normal cells. This process, called glycolysis, is inefficient and uses up vast amounts of sugar. Until now it had been assumed that cancer cells used glycolysis because their mitochondria were irreparably damaged. However, Michelakis's experiments prove this is not the case, because DCA reawakened the mitochondria in cancer cells. The cancer cells then withered and died.

Michelakis suggests that the switch to glycolysis as an energy source occurs when cells in the middle of an abnormal but benign lump don't get enough oxygen for their mitochondria to work properly (see Diagram). In order to survive, they switch off their mitochondria and start producing energy through glycolysis.

Crucially, though, mitochondria do another job in cells: they activate apoptosis, the process by which abnormal cells self-destruct. When cells switch mitochondria off, they become "immortal", outliving other cells in the tumour and so becoming dominant. Once reawakened by DCA, mitochondria reactivate apoptosis and order the abnormal cells to die.

This also explains how secondary cancers form. Glycolysis generates lactic acid, which can break down the collagen matrix holding cells together. This means abnormal cells can be released and float to other parts of the body, where they seed new tumours.

This re-kindles the old debate whether cancer is sparked by metabolism or mutation. This research tends to indicate metabolism as the primary cause.

The University of Alberta and the Alberta Cancer Board are committed to performing clinical trials in the immediate future in consultation with regulatory agencies such as Health Canada.

They believe that because DCA has been used on human beings in Phase 1 and Phase 2 trials of metabolic diseases, the cancer clinical trials timeline for our research will be much shorter than usual.

Source: New Scientist, University of Alberta