Page 167 - Haematologica April 2020

CD99 overexpression in AML
CD99 monoclonal antibody treatment exhibits antileukemiaactivityinacutemyeloidleukemiacells
Acute myeloid leukemia patient blasts (n=7) incubated with monoclonal CD99 antibody (mAbCD99: 20 μg/mL)
showed a significant decrease in cell viability (48 h: 0.5±0.02-fold, P<0.0001) (Figure 7A). Treatment with mAbCD99 caused a decrease in colony formation in 3 of 6 patient samples: AML-2 (0.5-fold, P=0.02), AML-6 (0.65-
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Figure 8. Effect of CD99 on ERK and SRC signaling pathways in acute myeloid leukemia (AML) cells. (A) Western blot analysis of SRC and ERK signaling pathways in THP-1 cells transduced with EV, CD99-L, and CD99-S lenti-virus for 72 hours (h). (B) Western blot analysis of SRC and ERK signaling pathways in THP-1 cells trans- fected with siCD99 for 48 h. (C) MDM2 western blot analysis in THP-1 cells transduced with EV, CD99-L, and CD99-S lentivirus. (D) MDM2 analysis performed by western blot in THP-1 cells treated with mAbCD99 for 1, 2, and 9 h. (E) ERK signaling pathway analyzed in THP-1 cells treated with mAbCD99 for 1, 3, and 9 h. (F) Cyclin D1 mRNA expression measured by taqman assay in THP-1 cells transduced with EV, CD99-L and <CD99-S lentivirus. (G) CCND1 mRNA expression measured by taqman assay in THP-1 cells transfected with siCD99. (H) Western blot analysis of SRC and ERK signaling pathways in THP-1 stable cells transduced with EV, CD99-L and CD99-S lentivirus. (I) SRC signaling pathway analyzed in THP-1 cells treated with mAbCD99 for 1 and 9 h. (J) ERK and SRC signaling pathway analyzed in MOLM-13 cells treated with mAbCD99 for 1, 2, 6, and 9 h. (****P<0.0001; *P<0.05).
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