Chromatin modifier MTA1 regulates mitotic transition and tumorigenesis by orchestrating mitotic mRNA processing

Area of Science:

• Molecular Biology
• Cancer Research
• Genetics

Background:

• Alternative splicing (AS) dysregulation in mitosis is a key driver of cancer.
• The role of oncogenic chromatin modifiers in cancer-related AS is not well understood.

Purpose of the Study:

• To investigate the role of cancer metastasis-associated antigen 1 (MTA1) in regulating alternative splicing during mitosis in cancer.
• To elucidate the molecular mechanisms by which MTA1 influences mitosis and tumorigenesis.

Main Methods:

• Utilized developed fCLIP-seq technology to identify MTA1-bound transcripts.
• Investigated the impact of MTA1 deletion on alternative splicing patterns of mitosis regulators.
• Assessed effects of MTA1 dysfunction on mitotic arrest, chromosome segregation, and chromosomal instability (CIN).

Main Results:

• MTA1 broadly interacts with and co-expresses with RNA-binding proteins (RBPs) across cancers, influencing mitosis-related AS.
• MTA1 binds to abundant transcripts at splicing motifs, regulating mRNA levels and AS patterns.
• MTA1 deletion disrupts dynamic AS switches of ATRX and MYBL2 during mitosis, leading to defective mitotic arrest, aberrant chromosome segregation, and CIN.

Conclusions:

• MTA1 is a critical regulator of dynamic RNA splicing during mitosis in tumorigenesis.
• MTA1 orchestrates the splicing of mitosis regulators, contributing to chromosomal instability and cancer progression.
• Understanding MTA1's role in splicing opens new avenues for cancer therapy targeting mitotic dysregulation.