Targeting of BCR-ABL: Lessons learned from BCR-ABL inhibition

In 1960 researchers reported that balanced translocation between chromosomes 22 and 9 resulted in the generation of Philadelphia chromosome. This breakthrough revolutionized our knowledge related to leukemia biology and contemporary studies revealed that chromosomal translocation resulted in the fusion between the 5' segment of BCR gene and 3' segment of the ABL gene to form BCR/ABL fusion gene. Research over the years has progressively and systematically improved our understanding of the genetic and proteomic basis of Leukemia. Genome-wide profiling studies, including genome sequencing and microarray analysis, have helped us in identification of different intracellular signaling cascades that are frequently mutated in Leukemia.  We partition this multi-component review into different sections related to biochemical characteristics of BCR-ABL+ cells, underlying mechanism of generation of mutations and crosstalk of BCR-ABL with various intracellular signaling cascades. We also summarize how BCR-ABL encoding mRNA is negatively regulated by different miRNAs and the strategies which are currently being used to effectively target BCR-ABL protein. We also provide an overview of the natural products which have been used for targeting of BCR-ABL protein. Better understanding of the protein network of Philadelphia positive leukemic cells will prove to be helpful in getting a step closer to personalized medicine.