Splicing modulator FR901464 is a potential agent for colorectal cancer in combination therapy

Area of Science:

• Oncology
• Molecular Biology
• Cancer Genetics

Background:

• FR901464 (FR) is an anticancer drug and a modulator of splicing factor 3B subunit 1 (SF3B1).
• Splicing modulators' efficacy in colorectal cancer (CRC) is under investigation, but their use in animal models is unconfirmed.
• The role of SF3B1 in CRC progression and FR's transcriptional effects in CRC require further elucidation.

Purpose of the Study:

• To investigate the efficacy and toxicity of FR901464 (FR) in colorectal cancer (CRC) models.
• To explore the association of SF3B1 mutations with FR resistance in CRC.
• To evaluate the potential of FR in combination therapy for CRC treatment.

Main Methods:

• Cytotoxicity assays (IC50) were performed on CRC cell lines and FR-resistant clones.
• SF3B1 sequencing was conducted on CRC samples and resistant clones.
• Xenograft models were used to assess FR efficacy and toxicity in vivo.
• Microarray analysis and qRT-PCR were employed to analyze gene expression changes.

Main Results:

• FR exhibited high cytotoxicity against CRC cell lines (IC50 < 1 ng/ml), with resistance emerging in clones with SF3B1 mutations.
• SF3B1 mutations were infrequent in CRC and associated with FR resistance.
• FR demonstrated significant tumor growth inhibition in a xenograft model but induced severe toxicity.
• FR downregulated Fanconi anemia genes (BRCA1/2) and 28 driver oncogenes.
• Combination treatment with olaparib showed synergistic effects in CRC cells.

Conclusions:

• FR shows potential for CRC treatment, but toxicity is a concern, suggesting combination therapy is preferable to monotherapy.
• FR's downregulation of BRCA1/2 suggests potential for synergistic effects with PARP inhibitors like olaparib in CRC.
• Combination strategies involving FR may offer a more effective and safer approach to CRC treatment.