Clinical Significance of Bromodomain-Containing Protein 9 in Colorectal Cancer

Area of Science:

• Molecular Biology
• Oncology
• Genetics

Background:

• Switch/sucrose nonfermentable (SWI/SNF) complexes are key regulators of gene expression via chromatin remodeling.
• A subtype, non-canonical BAF (ncBAF), involves the BRD9 gene, a known poor prognostic factor in various cancers.
• The specific role of BRD9 in colorectal cancer (CRC) remains largely unexplored.

Purpose of the Study:

• To investigate the prognostic significance of BRD9 in colorectal cancer (CRC).
• To elucidate the functional role of BRD9 in CRC cell behavior and tumorigenesis.

Main Methods:

• Immunohistochemical analysis of BRD9 expression in 124 colorectal cancer patient specimens.
• In vitro studies involving BRD9 knockdown in human CRC cell lines.
• RNA sequencing to identify BRD9-associated genes.
• In vivo assessment using a mouse subcutaneous tumor model.

Main Results:

• High BRD9 expression was significantly associated with poor overall and disease-free survival rates in CRC patients.
• BRD9 was identified as an independent prognostic factor for CRC via multivariate analysis.
• BRD9 knockdown reduced CRC cell migration and proliferation, and significantly inhibited tumor growth in vivo.
• RNA sequencing revealed potential associations between BRD9 and 13 genes, including CCN1.

Conclusions:

• BRD9 serves as an independent poor prognostic factor in colorectal cancer.
• BRD9 promotes CRC tumor proliferation, migration, and tumorigenicity.
• The CCN1 pathway may mediate BRD9's enhancement of cancer cell malignancy in CRC.