Ok, the headline may be slightly misleading. When it says ‘targeting’ it isn’t negatively affecting them. Instead it is a method off shutting of the recruitment of healthy cells by cancer cells. In this article published by New Scientist, there were two investigations looking into this recruitment phenotype.
T-Cells are core to the immune system in humans. Regulatory T-Cells are a subpopulation of T-Cells that are responsible for the active suppression of the immune system. Their role is vital in preventing autoimmune diseases as they aid in distinguishing foreign bodies from their own. Without this ability, the immune system would wreak havoc on ‘friendly’ cells.
The first investigation looked into the role of regulatory T-Cells in the production of breast cancer. The levels of regulatory T-Cells are much higher in women with large, aggressive tumours. The study, undertaken by an Oleg Eremin at University of Nottingham, looked into the effect of an anti-cancer drug cyclophosphamide on the chance of a relapse in women that had already undergone treatment for their breast cancer.
The idea originated from previous measurements of regulatory T-Cells in women before, during and post-treatment. The measurements indicated that regulatory T-Cells were well above their normal rates in women with large breast cancers – some women with up to six-times the normal amount. From these results, Eremin postulated that cancerous cells were able to somehow recruit these T-Cells. The upshot of this meaning that the immune system is suppressed and the cancer cells can happily survive and proliferate again.
Cyclophosphamide is a standard chemotherapy drug known to kill regulatory T-Cells. By affecting T-Cell regulatory function, cancer cells are unable to recruit any ‘accomplices’ and the immune system can begin to re-establish any anti-cancer defences. Using cyclophosphamide at low enough levels can reduce regulatory T-Cells without harming healthy cells.
Eremin treated his patients with a combination of cyclophosphamide and two other chemotherapeutic drugs. He then removed any further tumour masses and measured the regulatory T-Cell levels. He found that their levels had reduced dramatically but began to creep up as time passed.
His results seem promising and he claims to be monitoring the same women for another six months to see if the basis for further cyclophosphamide treatment is at all necessary.
The second investigation focussed on the metastasis of breast cancer to further organs such as the lungs or liver. The idea behind this investigation originates through the theory put forward by Clare Isacke of the Institute of Cancer Research in London. She theorised that the blocking of a particular protein in the blood can prevent the spread of cancerous cells.
Metastasised cells can essentially attach themselves to the lining of blood vessels upon the recruitment of this particular protein and then begin to proliferate in their new location. A further protein that Isacke lays claim to is one that actually binds to the protein found in the blood. She theorises thats the blocking of this receptor can drastically reduce levels of metastatic activity.
Both of these studies expand upon the idea of preventing cell proliferation as opposed to targeting the cancer cell itself. The idea of cutting-off the external supplies of a cancer cell lends the idea of isolating the disease and focussing on destroying the source of the disease. It is a very interesting concept. After all, there’s no smoke without fire.
The New Scientist article called ‘Cancers Recruitment of Healthy Cells Targeted’: http://www.newscientist.com/article/mg21628914.900-cancers-recruitment-drive-of-healthy-cells-targeted.html