Aberrant expression of MAPK1 and MCTS1 in chronic myeloid leukemia (CML).

Genomic amplification may result in aberrant gene expression and support development of cancer, including chronic myeloid leukemia (CML). In CML cell line K-562, we recently reported overexpression of TBX1 located at chromosomal position 22q11, focally co-amplified together with BCR, part of the CML hallmark fusion gene BCR::ABL1. Here, we extended that study, by identifying genomically amplified and overexpressed MAPK1/ERK2 at 22q11 together with MCTS1 at Xq22. Using pharmacological inhibitors and siRNA-mediated knockdown assays, our data collectively revealed novel regulatory connections between TBX1, MAPK1 and MCTS1, which may play a role in drug resistance.