A MYC-controlled redox switch protects B lymphoma cells from EGR1-dependent apoptosis

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Refractory and relapsed B cell lymphomas are driven by the MYC oncogene.
• MYC promotes lymphoma cell proliferation and inhibits apoptosis under normal oxidative stress.
• Targeting MYC in lymphomas remains a significant clinical challenge.

Purpose of the Study:

• To investigate the role of oxidative stress in MYC-driven lymphoma.
• To explore the therapeutic potential of N-acetylcysteine (NAC) and vitamin C (VitC) in MYC-driven B cell lymphomas.
• To elucidate the molecular mechanism by which NAC and VitC affect MYC function.

Main Methods:

• Assessing the impact of MYC expression on lymphoma cell proliferation and apoptosis.
• Evaluating the efficacy of NAC and VitC in reducing tumor growth in vitro and in vivo.
• Investigating the effects of MYC knockdown and activation on cellular responses to NAC and VitC.
• Analyzing the interaction between MYC, EGR1, and gene expression changes upon NAC and VitC treatment.

Main Results:

• High MYC expression enhances lymphoma cell proliferation and survival by protecting against apoptosis.
• NAC and VitC treatment reduce oxidative stress, inducing apoptosis and inhibiting tumor growth in MYC-high lymphoma cells.
• MYC knockdown confers resistance to NAC and VitC, while MYC activation increases sensitivity.
• NAC and VitC promote MYC binding to EGR1, shifting gene expression from cell cycle promotion to apoptosis induction.

Conclusions:

• MYC's oncogenic function in B cell lymphoma is linked to redox control of proliferation and apoptosis.
• NAC and VitC demonstrate therapeutic potential by targeting the MYC-EGR1 axis in MYC-driven lymphomas.
• These findings suggest a potential clinical strategy using NAC or VitC for patients with MYC-driven B cell lymphomas.