Application of array comparative genomic hybridization in chronic myeloid leukemia

Chromosomal alteration is one of the hallmarks of chronic myeloid leukemia (CML), and the Philadelphia chromosome is the most important and key example of the chromosomal changes in this disease. Indeed, the BCR - ABL1 fusion product is a target against which many tyrosine kinase inhibitors (TKIs) have been proven to be effective in the treatment of CML. However, the reality is that CML patients show resistance to TKIs both in an acquired and de novo manner, and the mechanism of TKI resistance is still largely unknown. This phenomenon suggests that in addition to the BCR - ABL mutation, further genetic alterations such as copy number aberration may be involved in unexplained TKI resistance. Although the recent array comparative genomic hybridization analyses (array-CGH) across the whole genome have detected multiple genetic aberrations in CML, the detailed feature of chromosomal alterations involved in different clinical phases of CML, such as chronic phase, accelerated phase, and blast crisis, remains unclear. Here we review the methodological aspects of array-CGH analysis for studying CML and its related data analysis.