NDRG2 contributes to cisplatin sensitivity through modulation of BAK-to-Mcl-1 ratio

Area of Science:

• Oncology
• Molecular Biology
• Cancer Therapeutics

Background:

• Downregulation of N-Myc downstream-regulated gene 2 (NDRG2) correlates with cancer progression and poor prognosis.
• NDRG2, induced by p53, sensitizes cancer cells to chemotherapy, but its role in apoptosis induction during treatment is understudied.
• Understanding NDRG2's function is crucial for developing novel cancer treatment strategies.

Purpose of the Study:

• To investigate the role of NDRG2 in chemo-sensitivity, specifically its effect on cisplatin treatment in U937 histiocytic lymphoma cells with p53 mutations.
• To elucidate the molecular mechanisms by which NDRG2 influences sensitivity to chemotherapy.

Main Methods:

• Utilized U937 histiocytic lymphoma cells with a loss-of-function p53 mutation.
• Overexpressed NDRG2 in U937 cells (U937-NDRG2) to study its effects.
• Analyzed the BAK-to-Mcl-1 ratio, JNK activation, eIF2α/p-eIF2α pathway, PKR activation, NOX5 expression, and reactive oxygen species (ROS) production.
• Assessed the impact of ROS scavenging and NOX5 knockdown on cisplatin sensitivity.

Main Results:

• NDRG2 overexpression increased sensitivity to cisplatin in U937 cells.
• This sensitization was mediated by modulating the BAK-to-Mcl-1 ratio.
• NDRG2-induced Mcl-1 degradation and BAK increase involved JNK activation and the eIF2α/p-eIF2α pathway, dependent on PKR activation.
• NOX5 expression and ROS production were elevated in NDRG2-overexpressing cells and contributed to cisplatin sensitivity.

Conclusions:

• NDRG2 enhances cisplatin sensitivity by modulating the BAK-to-Mcl-1 ratio via the NOX5-ROS-PKR pathway.
• NDRG2 plays a significant role in promoting apoptosis and chemo-sensitivity in p53-mutated lymphoma cells.
• NDRG2 represents a potential molecular target for improving the efficacy of chemotherapy in cancer patients.