Multimodal effects of small molecule ROCK and LIMK inhibitors on mitosis, and their implication as anti-leukemia...

Area of Science:

• Cell Biology
• Molecular Oncology
• Drug Discovery

Background:

• Accurate chromosome segregation is crucial for cell viability, but cancer cells often exhibit chromosome instability (CIN).
• Targeting CIN with small molecule inhibitors that induce segregation errors is a promising strategy for selective cancer cell killing.
• Aberrant gene expression in cancer cells contributes to chromosome segregation defects.

Purpose of the Study:

• To screen and characterize small molecule inhibitors that induce mitotic chromosome segregation errors.
• To investigate the mechanism by which these inhibitors affect chromosome segregation and cancer cell growth.
• To evaluate the therapeutic potential of targeting specific kinases in T cell leukemia.

Main Methods:

• Screening of approximately 300 small molecule inhibitors with known targets.
• Investigating the effects of Rho-associated coiled-coil kinase (ROCK) inhibitors on chromosome segregation and spindle assembly checkpoint (SAC).
• Assessing the impact of ROCK and LIMK inhibition on centrosome integrity, microtubule dynamics, Aurora-A activation, and apoptosis in cancer cells.

Main Results:

• ROCK inhibitors bypassed the SAC, inducing microtubule-dependent centrosome fragmentation.
• Knockdown of ROCK1 and ROCK2 demonstrated their additive roles in maintaining centrosome integrity.
• Inhibition of ROCK or LIMK hyper-stabilized mitotic spindles, impaired Aurora-A activation, and induced centrosome fragmentation and apoptosis in T cell leukemia cells.
• ROCK and LIMK inhibition suppressed T cell leukemia growth in vitro without affecting normal peripheral blood mononuclear cells.

Conclusions:

• ROCK and LIMK are involved in regulating microtubule dynamics and Aurora-A activation.
• ROCK and LIMK inhibition represents a potential therapeutic strategy for targeting T cell leukemia by inducing catastrophic chromosome segregation errors.
• Targeting ROCK and LIMK may offer a selective approach to anti-cancer drug development for specific leukemias.