The human DEK oncogene regulates DNA damage response signaling and repair

Area of Science:

• Molecular Biology
• Cancer Research
• DNA Repair Mechanisms

Background:

• The human DEK gene is frequently overexpressed and amplified in various human cancers.
• DEK overexpression and amplification correlate with oncogenic functions, as Dek knockout mice show resistance to chemically induced papilloma formation.
• DEK knockdown sensitizes cancer cells to DNA damaging agents, inducing cell death through p53-dependent and -independent pathways.

Purpose of the Study:

• To investigate the role of the DEK gene in DNA double-strand break repair.
• To elucidate the molecular mechanisms linking DEK to DNA damage response signaling pathways.

Main Methods:

• DEK depletion in human cancer cell lines and xenografts.
• Assessment of DNA damage response markers such as γH2AX and FANCD2.
• Analysis of ATM and DNA-PK pathway activation/suppression.
• Study of DNA damage, senescence, and non-homologous end joining (NHEJ) in Dek knockout mouse embryonic fibroblasts (MEFs).

Main Results:

• DEK depletion induced DNA damage response, evidenced by increased γH2AX and FANCD2.
• Contrasting activation and suppression of ATM and DNA-PK pathways were observed.
• Dek knockout MEFs exhibited increased DNA damage, exaggerated senescence, and distinct defects in NHEJ compared to wild-type MEFs.

Conclusions:

• DEK is important for DNA double-strand break repair.
• DEK depletion activates DNA damage response signaling pathways.
• DEK contributes to the maintenance of genomic stability, particularly through its role in NHEJ.