Could Proteomics be the Future of Cancer Therapy?
Although still a relatively new science, Proteomics is gaining a lot of attention because of its potential as a cancer diagnosis tool and treatment. Millions of dollars a year are being poured into this novel research so that hopefully, the next generation will be able to diagnose and treat cancer with unbounded success.
What is Proteomics?
Proteomics is described as the study of the structure and functions of the body’s proteins. Proteins are responsible for much of the chemical activity at a cellular level and so by studying how protein structure and function change when diseases such as cancer are present, researchers are hoping to identify which specific proteins play a role in the disease. The proteins that are ultimately found to be associated with a disease are called biomarkers and it is these particular proteins that drug therapies will then target. Unfortunately the human genome consists of around 35000 genes and each of these genes can code for up to ten times as many proteins. Thus, only a very small percentage of the body’s proteins have so far been identified which means the field of Proteomics still has a long way to go before it can be used on a daily basis to diagnose and treat cancer.
Proteomics research is currently concentrating on a number of areas which will all help to make the diagnosis and treatment of cancer much easier. These research areas include:
- Ascertaining the function of common proteins. This means that if a cell or an organ begins to function less effectively researchers will know which particular protein has become mutated or is absent.
- Determining the 3-dimentional structure of a protein. Ultimately this will help when developing drug therapies to target specific proteins.
- Using Mass Spectrometry and other technologies to identify the exact amino acid sequences that make up important proteins. Sometimes it only takes a single amino acid to be replaced with a different one for a protein to stop working and so by knowing the correct amino acid sequence for a particular protein a comparison software application can be developed whereby abnormal proteins are quickly identified.
- Ascertaining how different chemicals such as phosphates and sugars affect the functioning of a protein. Once an abnormal protein has been identified it will be necessary to affect its functioning and so this type of research will help to develop new drug therapies that target one particular protein.
Potential for Proteomics in the treatment of cancer
As already mentioned the cells of the body manufacture thousands of different proteins each and every day. In the majority of cases these proteins are normal and simply do the job that they are manufactured to do however very occasionally something goes wrong during the production process and a new protein is formed that can’t complete its designated function. Sometimes this novel protein is harmless however if for example the original protein acted to stop a cell from replicating then without it the cell will replicate over and over again without any form of control system. Over time this may form into a tumour or a cancer.
Proteomics will eventually be able to take a sample from a patient and using sophisticated computer software break the sample down so that every protein present is identified i.e. by analysing its 3-dimensional structure and its amino acid sequence. The software will then compare the patient’s proteins to those of a normal healthy sample and any mutated proteins or absent proteins will be flagged. By building up a database of specific proteins that are commonly associated with particular diseases, new cases of a disease will hopefully be diagnosed quickly and effortlessly and in many cases even before signs and symptoms of the disease become apparent to the patient.
Research in America is currently focussing on cancers which show very few signs and symptoms before they reach the advanced stages when there is little hope of curing the disease, so for example ovarian and prostate cancers. In this case Proteomics is being used as a diagnostic tool and early data from the projects have been very positive with the computer software managing to identify 100% of ovarian cancer samples (when compared to a healthy sample) and 96% of prostate cancer samples. With these positive results it is surely only a matter of time before diagnostic Proteomics is seen in a clinical setting.
In addition to its role in diagnosing cancer, the field of Proteomics is also making headway in developing new drug treatments for the disease. Currently, drug treatments for cancer are not specific to the cancerous cells and so normal healthy cells can also be affected by certain drug regimens, hence the common side effects associated with chemotherapy. The main aim of Proteomics research with regards to therapy however, is to identify cellular biomarkers i.e. proteins specific to the cancerous cells, and to target them explicitly. This would mean that only cells containing or manufacturing the biomarker would be affected by the drug therapy, the result being that many of the adverse side effects associated with current chemotherapeutic agents would become a thing of the past. In addition, cancer drugs could be manufactured to order so that an individual course of treatment could be developed for a specific patient, the components of which target and interfere with the functioning and development of their exact biomarkers and their exact cancer. This would undoubtedly make drug treatments much more effective and much less troublesome with regards to adverse affects.
While Proteomics sounds like it could be the future for cancer patients there are still many years of research ahead of the scientists. Only a very small number of the 250 thousand or so proteins that are thought to be manufactured by human cells have so far been identified and sequenced. Luckily however research is happening all over the world with millions of pounds and dollars being poured into the science each year. This means that hopefully the next generation should reap the rewards of our current Proteomics research.