BubR1 depletion delays apoptosis in the microtubule-depolymerized cells

Area of Science:

• Cell Biology
• Cancer Research
• Pharmacology

Background:

• Spindle assembly checkpoint (SAC) proteins, like BubR1, are crucial for accurate chromosome segregation during mitosis.
• Anti-microtubule agents are a class of chemotherapy drugs that disrupt microtubule dynamics, leading to cell cycle arrest and apoptosis.
• Understanding the precise mechanisms of cell death induced by these agents is vital for optimizing cancer therapy.

Purpose of the Study:

• To investigate the role of BubR1 in the mechanism of cell killing by the anti-microtubule agent CXI-benzo-84.
• To determine if mitotic arrest is a prerequisite for apoptosis induction by anti-microtubule agents.
• To explore the potential of combination therapy in BubR1-compromised cancer cells.

Main Methods:

• Utilized MCF-7 breast cancer cells with and without BubR1 depletion.
• Treated cells with the anti-microtubule agent CXI-benzo-84.
• Assessed microtubule dynamics, mitotic arrest, apoptosis, and DNA damage.
• Investigated the combined effect of CXI-benzo-84 and cisplatin.

Main Results:

• CXI-benzo-84 dampened microtubule dynamics and induced mitotic arrest and apoptosis in control MCF-7 cells.
• BubR1 depletion prevented mitotic arrest but did not abolish apoptosis induction by CXI-benzo-84.
• BubR1 depletion enhanced DNA damage and increased cell death when CXI-benzo-84 was combined with cisplatin.

Conclusions:

• Mitotic block is not essential for apoptosis induction by anti-microtubule agents.
• BubR1 status affects cellular response to anti-microtubule chemotherapy.
• Combination therapy involving CXI-benzo-84 and cisplatin shows promise for treating cancers with compromised BubR1 function.