The CRISPR Approach to Molecular Systems Biology and Personalized Medicine

Introduction: Commonly employed in biological research, reductionism strives to study the cellular components individually. In contrast, holism aims at examining all the components of the cell together. The importance of the holistic approach to cell biology is better appreciated once we know that the cellular components do not function in isolation and that all the components are interconnected. The task of the systems biology is to examine all the components of a cell together. Recently, CRISPR-based genome-scale investigations have been employed to shed light on the genes that confer resistant on cells or make them prone to different chemotherapeutic drugs (drug vemurafenib used in the treatment of melanoma), infection by viruses (the influenza virus) and so forth. Vemurafenib works against BRAF protein which is constitutively active in melanoma cells.Method: Figuring out which genes are behind resistance and which ones behind susceptibility to Vemurafenib would allow the treatment to be tailored in a patient-specific manner. This is carried out using a CRISPR library called GeCKO which targets one gene per cell. A control group infected by lentiviral particles but not treated with vemurafenib is used as reference point so as to determine which gRNAs are depleted and which ones are overrepresented in cells infected and treated with Vemurafenib.Result: Target melanoma cells become susceptible to vemurafenib when genes making them resistant are perturbed. Therefore, when sequencing NGSs, the reads of gRNAs that act against these genes are reduced compared to the control. Genes making melanoma cells susceptible to Vemurafenib are conversely read in higher numbers as their ablation results in resistance. Therefore, by having a constellation of such genes we can assay each individual patient to see which mutations they harbor so as to tailor their treatment regimen based on their particular mutation index.

کلیدواژه ها:

Systems Biology ، Genome-wide CRISPR Investigation ، Personalized Medicine