Science - Cancer and the Push towards Personalised Treatments

Cancer - The Push towards Personalised Treatments

         Whereas previously cancers were defined by their position inside the body, advances in the field of oncology are increasingly revealing that primarily similarity between cancers is as a result of similar genetic mutations different cancers may cause. This means that a particular lung cancer may have more in common with a specific breast cancer than another type of lung cancer. This has profound repurcussions in the medical field where currently treatments are prescribed by a clinician based primarily upon the severity and location of the cancer in the body. However, with each cancer having the possibility of causing over 100,000 genetic mutations inside cancerous cells current genetic sequencing equipment is, at present, insufficient in terms of efficiency and economic viability to be used to sequence the DNA of the UK's many thousands of cancer patients. The reason for these problems with the equipments efficiency in coding a patients genetic code becomes clear once it is realised that storing one million cancer patients genetic codes would require as much space as Youtube.

        The Institute of Cancer Research (ICR) is pouring funding into new projects designed to provide greater insight into which mutations cause tumour suppressor genes to lose function. If tumour suppressor genes become inactivated they can no longer inhibit cell proliferation leading to uncontrollable cell growth and the formation of a tumour. By understanding which mutations cause healthy cells to convert into cancerous cells it is hoped that improved treatments specific to an individuals own particular type of cancer. Rapid advances in genetic sequencing techniques are catalysing this progression towards personalised treatments. One of the most established of these new 'personalised' treatments is the drug Herceptin. Herceptin is already being used to treat certain types of breast and stomach cancers in which the protein HER2, which stimulates cell division, is over expressed. However, such treatment is immensely expensive costing over £65,000 ($100,000) for a years treatment of Herceptin resulting in numerous American insurance companies and the NHS in Britain being reluctant to prescribe such treatments. Despite the expense of such treatments the ICR is hopeful of improvements in genetic sequencing and the development of new drugs reducing the costs.

        However, treatments specific to particular mutations (in what are rapidly proliferating and mutating cancerous cells) are then face with the problem of tumours developing resistance. Prof. Alan Ashworth, the ICR's director, has detailed the disappointment he feels when promising new drugs failing after the cancer develops resistance after only a few months. Describing the ICR's battle against cancer as a "bit like the game whack-a-mole" with the re-emergence of a cancer after it has seemingly been eradicated by a new treatment. The Tumour Profiling Unit at the ICR is understood to be planning to undertake a programme of frequent testing of cancer sample in order to understand changes the tumour undergoes in order to achieve such resistance. 

    Newly unveiled government plans to record the entire genetic sequences of over 100,000 patients with cancers and rare diseases clearly shows the governments commitment to stimulating progress towards more personalised treatments. The potential benefits of such plans to researchers is significant and scientists are already predicting implementation of new, faster genetic sequencing techniques into the NHS within the next 10-15 years.

-Adam

      

        

Science - Quadruple Helix

The Quadruple Helix

        Cambridge University Scientists have recently discovered quadruple helices made up of four strands of DNA intricately laced together. Although such a molecule has previously been produced in vitro under laboratory conditions the discovery of the molecule in cancerous cells is the first known example of a quadruple helix structure of DNA in naturally occurring human cells. The Quadruple Helix, scientifically called a G-Quadruplex, is most commonly found in regions of DNA rich in the nitrogenous base guanine. G-Quadruplexes occur in greatest abundance during the 's phase' of cell replication and are formed inside chromosomes and telomeres.

    

     The discovery of the G-Quadruplex is of keen interest to the field of oncology due to the fact the molecule has only been identified inside cancerous cells. This means the G-Quadruplex could potentially have a role in whether a cell becomes cancerous in the first place. 

More significantly, however, is the possibility of new treatments being developed which specifically target the G-Quadruplex without damaging healthy cells. For years the 'holy grail' of oncology is to find a characteristic specific to all cancer cells alone which would allow such characteristics to be targeted without damaging healthy cells, destroying the cancer. Indeed, Professor Shankar Balasubramanian of the University of Cambridge's Department of Chemistry has already detailed “...links between trapping the G-Quadruplexes with molecules and the ability to stop cells dividing” suggesting that the Quadruple Helix has a significant role in leading to the uncontrollable and rapid division of cells in cancer. 

Further research into the G-Quadruplex, therefore, could pave the way for more effective and more personalised cancer treatments in the near future. Many research scientists have already begun advocating the benefits of potential treatments to pharmaceutical companies in order to get the next generation of cancer treatments along the development pipeline.

-Adam

                                                                                                    

For more detailed information please have a look at this excellent New Scientist article:

http://www.newscientist.com/article/mg21729014.400-quadruple-helix-dna-discovered-in-human-cells.html

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