The Rac1-inhibitor EHop-016 attenuates AML cell migration and enhances the efficacy of daunorubicin in MOLM-13 transplanted zebrafish larvae
Ras-related C3 botulinum contaminant substrate 1 (Rac1) is really a GTPase implicated in cell migration and homing of hematopoietic cells towards the hematopoietic niche, and it is generally overexpressed in acute myeloid leukemia (AML). This may lead to quiescence of leukemic blasts within the niche and reduced reaction to therapy. We investigated the Rac1 inhibitor EHop-016 on AML by assessing its effects on MOLM-13 cells in vitro as well as in zebrafish larvae, regarding cell motility and therapeutic potential in conjunction with daunorubicin (DNR). In vitro assessment of proliferation and viability was by measurement of 3H-thymidine incorporation and recognition of Annexin V/PI positive cells. Cell motility was evaluated by measurement of migration inside a transwell system. Fluorescently stained MOLM-13 cells were injected into zebrafish larvae, and individual cells adopted by confocal microscopy. Cell accumulation within the caudal hematopoietic tissue (CHT) was studied utilizing a 12-hour timelapse, during vivo effectiveness of DNR, EHop-016 or perhaps a combination was investigated over 24 h. The in vitro results demonstrated that EHop-016 acted synergistically in conjunction with DNR in lessening the viability of MOLM-13 cells (Bliss synergy score above ten percent). Non-toxic concentrations of EHop-016 reduced cell migration. These bits of information were reproduced in zebrafish larvae: larvae receiving both DNR and EHop-016 had considerably reduced tumor burden when compared to untreated control or single treatments. The buildup of MOLM-13 cells within the CHT was reduced in larvae receiving EHop-016 treatment. Our findings show targeting Rac1 in AML holds promise like a complementary treatment to established chemotherapy and really should be further investigated.