The future? Cancer Stem Cells

Stem cells are the natural repair cells of the body – they exist throughout the body and are replaced from the bone marrow. When damage occurs, the stem cells collect in the area of damage and can differentiate (change) into the required cells.  After conception, these ‘blank’ stem cells are the early cells of the foetus in the first 50 days, growing very rapidly prior to their differentiation into all types of normal cells like heart, lung, kidney, bone, skin and blood cells. 

In 2004 Professor Wang and his team in Columbia University claimed a ‘breakthrough’ in cancer understanding, adding that traditional cancer books would have to be torn up and re-written.  They noted that irritation in the stomach wall drew stem cells in to repair the problem but that under the effect of localised oestrogen they didn’t change to stomach lining cells but remained as rapidly dividing stem cells driving stomach cancer

Unfortunately for Wang, his enthusiasm overlooked the fact that the English embryologist John Beard, whilst working in Edinburgh, had come to exactly the same conclusions in 1906.

Dr John Beard first reported his observations that stem cells might get stuck in their rapidly dividing form when observing the foetus and that a flood of pancreatic enzymes occurring around day 52 seemed to cause their switch to normal healthy, differentiated cells. He postulated that cancer was like having a baby growing in the wrong place at the wrong time. His work was ignored.

At CANCERactive we have followed this work closely. It was resuscitated and developed in America in the 1970’s by William Kelley, and is now being used by Dr Nicholas Gonzalez in New York. He treats people with pancreatic enzymes since they seem capable of converting the stem cells into ‘normal’ cells. He produced Clinical Trials on his work and showed great success. Unfortunately, a full scale Clinical Trial was taken out of his hands and completely ruined by insufficient patients, unequal control groups and so on. So we don’t know if stem cells that lie behind cancer can simply be turned off by pancreatic enzymes, for the moment.

At CANCERactive, as regular readers will know, we have always argued that your cancer is as individual as you are, there may be many forms a cancer takes and it may develop in many ways. One of those ways could well be the Wang hypothesis above. But, do we believe all cancers are caused by stem cells? It is unlikely. Stem cells have been found to lie behind many types of cancer like leukaemia, brain tumours, colon, stomach, breast cancer and more. But not in every case. And this may account for the hot debate over the last 5 or more years; a debate the pro-cancer stem cells lobby argues it has now convincingly won. 

Evidence has been steadily increasing that small numbers of stem cells within tumours actually orchestrate the growth and proliferation of cancer.

In May 2012 three independent research groups found direct evidence for cancer stem cells in solid tumours of the brain, skin and digestive system and all simultaneously published their findings in the journals Science and Nature.

But there were important conclusions:

1. They were difficult to kill using chemotherapy as they had a ‘filtering’ defence system protecting them against chemicals. Where not eradicated by standard chemotherapy, they lived to fight another day and create a revitalised tumour.

2. There is a hierarchy of cancer cells within a solid tumour and at the top of the hierarchy are cancer stem cells that are ultimately responsible for causing the tumour to flourish, according to a team of scientists from the University of Texas Southwestern Medical Centre in Dallas and led by Luis Parada.

3. Hugo Snippert, of Utrecht University in the Netherlands after proving that cancer stem cells existed in his studies on intestinal tumours claimed tumours are like caricatures of the tissues from which they were derived. They are composed of different cell types and there is a hierarchy between the types. Just as normal tissues have healthy stem cells, tumours have cancer stem cells at the basis of their cellular turnover, he stated.

4. Treatments should be focused in future on killing these cells rather than targeting the wider community of tumour cells, said Parada, adding, In the past we’ve tried to get rid of the entire stew of cells within cancer tumours. But shrinking a tumour by 50 per cent is irrelevant. What you need to know is whether you’re targeting the stem cells that allow a tumour to regrow. The good news is that now we know what to go after.

Work at Bart’s Hospital, and in the Blizzard Institute in London has now succeeded in extracting cancer stem cells from tumours, putting their existence beyond doubt.

Professor Mackenzie and his colleague Dr Adrian Biddle at Bart’s along with fellow research teams from Cambridge and Manchester to Texas and Massachusetts are gradually honing and proving the theory.

‘All stem cells seem particularly resistant to current drug therapies but certainly those with slug-like characteristics are very nasty indeed. We’ve found both types of cell in head and neck tumours, and others have found them in breast, colon and several other types of cancer. If we could find ways to target them, we might have an elegant solution to the problem of cancer and its growth. But the question is, how can you target cancer stem cells without damaging normal stem cells? We don’t know yet. But cancer stem cells do have a different metabolism, so the hope is we can target and exploit these differences’, said Mackenzie. 

GlaxoSmithKlein (GSK) has already put $1.4 billion into the American cancer research company OncoMed in 2007 to develop cancer stem cell therapies. It’s early days yet.

What has become clearer by the day is that cancer stem cells act just like normal stem cells in that they have the properties of self-renewal and differentiation, according to Young S. Kim, M.D. of the National Cancer Institute in Bethesda and her team. And if they can differentiate, then there is hope possibly from natural compounds like pancreatic enzymes as Beard, Kelley and Gonzalez have told us.

Young S Kim at the NCI and her team intriguingly reported that bioactive food components, which are available in foods or as dietary supplements, may have a capacity to suppress cancer stem cells or prevent them from self-renewal. As Chris Woollams told you in the CANCERactive publication, ‘the Rainbow Diet and how it can help you beat cancer’, certain natural compounds have the ability to protect and correct. 

The NCI researchers say eating inappropriate foods and their ingredients may result in the loss of regulatory molecules and promote the aberrant or uncontrolled self-renewal of cancer stem cells. But eating other foods containing specific natural compounds can stop the self-renewal. 

´The ability of these bioactive food components to influence the balance between proliferative and quiescent cells by regulating critical feedback molecules in the network including dickkopf 1 (DKK-1), secreted frizzled-related protein 2 (sFRP2), B cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) and cyclin-dependent kinase 6 (CDK6) may account for their biological response.´ (Kim et al., Journal of Nutritional Biochemistry; July 2012)

Let’s be clear. Researchers from America’s top cancer body are saying that bad foods may promote cancer stem cells but these cells can still turn into good, normal cells and certain natural compounds can help them make that step change. And what natural compounds did they study?

All of these, according to the researchers, have been demonstrated to be able to modify self-renewal properties of cancer stem cells. They termed these compounds Biotics and stated that all could be found as supplements. We told you about all of these foods and their effects some six or more years ago. 

Are these foods in your anti-cancer Integrative Programme?