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Application of molecular biology to medicine
Posted on March 19th, 2010 No commentsModern medicine is based on evidence. Despite few years ago, physicians based their diagnosis and therapies on their previous experiences, now clinical trials, approved protocols and worldwide accepted treatment help physicians to make the better choice for their patients. To reach this important goal, molecular medicine gave a big contribution. Molecular medicine is a novel branch of medicine in which molecular biology or biochemistry techniques are usually used to accomplish exams and screening or diagnose the diseases. Molecular biology labs have worked as research and development department to improve protocols or set up novel methodologies at the beginning just to be used for research purposes, then applied to diagnosis. For instance, we could focus our attention on the polymerase chain reaction, namely the PCR.
This techniques has been developed to produce DNA portion in vitro and has quickly revolutionized molecular biology, allowing cloning, sequencing and in general gene manipulation. The improved type of PCR, the real time PCR is now currently used in modern hospital to detect certain diseases, such as recidivate leukemia in patients’ blood or gene signature in familial diseases. Other important tools which have found a good application in diagnosis are the monoclonal/ polyclonal antibodies. Several techniques employed antibodies to detect proteins in cellular lysates through western blotting, or directly in whole cells, through the immuno-chemistry and molecular imaging. As well as, it’s also possible to purify small amount of native protein through immuno-precipitation and so on. Antibodies are really largely used in biochemistry labs and some techniques are applied also in diagnostic labs.
For instance, we can talk about the ELISA assay, normally used to quantify serum proteins or cell sorting analysis, in which some antibodies that specifically recognize surface proteins are used to separate different kind of cells. Finally, also cellular biology gave important results in modern medicine. The capability to culture in vitro cellular populations changes the therapeutic opportunity for a lot of diseases. For instance, now it’s possible to select healthy cellular population in leukemic patient, propagate it in vitro and then draft it, reducing in this way several problems of rejection and immuno-suppressive events. We can continue to talk about other examples of molecular, biochemical or cellular protocols that have found a great application in clinics. This overview strongly confirms how scientific advances are important because they have an immediate benefit on modern medicine and as a consequence on the human life. It’s important to remember that not only good protocols, but also good quality of science and good data management and reporting are two further parameters to improve modern medicine, but this is the topic for another post!!! -
Minicells to target tumour cells
Posted on July 20th, 2009 No commentsA difficult challenge in cancer therapeutics is to develop drugs that can overcome the heterogeneity and resistance of cancer cells. A tumor usually consist on several type of cells that contribute to tumor growth, tissue invasion and metastasis in different way. Furthermore, during a treatment drugs become ineffective because of survival of cells that escape death induced by drug.
Small minicells derived form bacteria was used to targeted delivery of drug into cancerous cells. Antibodies can target minicells to tumor cell surface receptors and release drug at the specific site. A recent publication demonstrated how it was possible to subsequently administrate short hairpin RNA and cytotoxic drug in order to firstly knock down a multidrug resistance protein, then kill the cells made vulnerable. This strategy was tested on xenograft tumor in mice model and gave the opportunity to tune the dosage of cytotoxic drug, diminishing adverse effects. Minicells were not toxic for animals and didn’t compromise their survival: this approach seems promising to specifically treat resistant tumor and the use of shRNA allows to personalize the treatment. Other important challenges in next future will be the discovery of other route to target minicells, because resistance mechanism will be early developed to decrease receptor expression on cell surface. -
SPR a tool to study protein-protein interactions
Posted on June 8th, 2009 No commentsSurface plasmon resonance (SPR) is the best technique to explore protein- protein interactions. In particular, SPR is important to study multiple interactions simultaneously in a proteomic approach. How does SPR work?
Protein partner, potentially interacting with your protein of interest is bound on gold coated glass slide and a solution containing your protein is flowed across the slide’s surface. When a biomolecule is attached to gold surface, so when your protein and its partner interact, the refractivity of gold changes and different angle of light can be measured. SPR was set up for the first time in 1990, and very big advances have been done for this technology. Now SPR microscopy has been proposed. The novelty of this approach consists on studying protein- protein interactions in a flat array. In this way, it’s possible to save reagents and time and increase the efficiency. Arrays of DNA, peptides, antibodies and carbohydrates are frequently reported. In certain cases aptamers substitute antibodies in order to obtain more robust interaction. The challenge of this technology is choosing the right surface and functionalise it in the best way. In an array spots have to be properly separated but the extension of surface chemistry is totally chosen by researcher and this is a great advantage.
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