Knockdown of core binding factorβ alters sphingolipid metabolism

Area of Science:

• Molecular Biology
• Cancer Research
• Cellular Metabolism

Background:

• Core binding factor (CBF) is a transcription factor complex involving RUNX proteins and CBFβ.
• RUNX1 and CBFβ are frequently altered in leukemia, and CBF is implicated in epithelial cancers like ovarian cancer, promoting malignancy and metastasis.
• CBF's role in maintaining cancer phenotypes necessitates understanding its regulatory mechanisms.

Purpose of the Study:

• To investigate the functional consequences of CBFβ reduction in ovarian cancer cells.
• To explore the relationship between CBFβ, autophagy, reactive oxygen species (ROS), and sphingolipid metabolism.
• To determine if modulating ceramide synthesis can impact cell survival in CBFβ-silenced cells.

Main Methods:

• Lentiviral delivery of short hairpin RNA (shRNA) to silence CBFβ expression in an ovarian cancer cell line.
• Assessment of cell growth, cell cycle, apoptosis, autophagy, and ROS production.
• Treatment with fumonisin B1 (FB1), a ceramide synthase inhibitor, and mass spectrometry to analyze sphingolipid levels (ceramide, lactosylceramide).

Main Results:

• CBFβ silencing led to significant growth inhibition without affecting cell cycle or apoptosis, but increased autophagy and ROS.
• FB1 treatment reduced CBFβ-induced autophagy and improved cell survival.
• Mass spectrometry revealed increased ceramide species and decreased lactosylceramide levels in CBFβ-silenced cells.

Conclusions:

• CBF transcriptional pathways are critical for ovarian cancer cell survival.
• CBFβ regulates cellular processes including autophagy and ROS production, partly through sphingolipid metabolism.
• Targeting sphingolipid metabolism represents a potential therapeutic strategy in cancers where CBF is dysregulated.