Morgana underexpression synergizes with BCR-ABL and negatively affects CML treatment efficacy. (A) Western blot analysis of BM protein extracts from 2 representative Morgana normal and Morgana low Ph⁺ CML patients stained with antibodies against morgana, phosphorylated MLC2 (P-MLC2), total MLC2, and tubulin. The graphs show the densitometric quantification of morgana bands normalized to tubulin and P-MLC2 bands normalized to total MLC2 (n = 4 patients per group). (B) Correlation between normal and low morgana expression levels and patients’ molecular response during TKI treatment in CML patients stratified for the levels of expression of morgana by IHC (Morgana normal, n = 9; Morgana low, n = 3). (C) Dose-response curves of K562 infected with an empty vector (empty) or with vectors carrying 2 different shRNAs against morgana (shmorgana1 and 2) treated for 48 hours with different imatinib concentrations (0.005-0.1-0.5-1-5-10-20-50 μM) analyzed by MTT assay (mean r² = 0.98). Viability was expressed as a percentage of untreated cells. (D) Percentages of apoptotic K562 empty or shmorgana1 in response to 48 hours’ treatment with imatinib (1 μM), imatinib (1 μM) + fasudil (10 μM), and imatinib (1 μM) + Y27632 (20 μM). (E) Western blot analysis of K562 empty and shmorgana stained with antibodies against morgana, ROCKI, ROCKII, P-MYPT1, MYPT1, P-MLC2, MLC2, PTEN, P-AKT, AKT, P-STAT5, STAT5, and tubulin. (F) Apoptosis quantification of BM cells from Ph⁺ patients cultured in the presence of imatinib (10 μM), the ROCK inhibitor fasudil (10 μM), or a combination of the 2 drugs (Morgana normal, 6 patients; Morgana low, 9 patients). Bars represent the percentages of Annexin V–positive cells for each treatment. (G) Mean of apoptosis fold-induction calculated on BM cells treated with imatinib and fasudil vs imatinib alone for each individual patient. *P < .05, **P < .01, ***P < .001.