A CDCA2-MYC positive feedback loop controls cancer cells survival.

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• MYC transcription factors (MYC, MYCN, MYCL) are frequently altered in human cancers.
• MYC protein stability and activity are regulated by phosphorylation, but counteracting phosphatases remain understudied.
• CDCA2 (Repo-Man) is a chromatin-associated protein phosphatase 1 (PP1) regulatory subunit.

Purpose of the Study:

• To investigate the role of CDCA2 in regulating MYC proteins in cancer cells.
• To determine if CDCA2 impacts the stability and viability of cancer cells dependent on MYC.
• To explore the therapeutic potential of targeting the CDCA2-MYC interaction.

Main Methods:

• RNA interference and degron-mediated degradation were used to manipulate CDCA2 levels.
• Cell viability assays were performed on triple-negative breast cancer, neuroblastoma, and colon cancer cells.
• Proximity ligation assays were employed to assess in vivo proximity of CDCA2 to cMYC and MYCN.

Main Results:

• CDCA2 depletion significantly reduced cMYC and MYCN stabilization.
• Loss of CDCA2 impaired the viability of triple-negative breast cancer, neuroblastoma, and colon cancer cells.
• Proximity ligation assays confirmed that cMYC and MYCN are in close proximity to CDCA2.
• CDC2A was identified as a direct MYC target gene, indicating a reciprocal regulatory loop.

Conclusions:

• CDCA2 is essential for stabilizing cMYC and MYCN in various cancer types.
• CDCA2 plays a critical role in maintaining the viability of MYC-dependent cancer cells.
• The reciprocal regulatory loop between CDCA2 and MYC presents a potential therapeutic vulnerability in cancer.