Targeting MYC and BCL2 by a natural compound for "double-hit" lymphoma

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Double-hit lymphoma (DHL) is characterized by concurrent MYC and BCL2 translocations, leading to aggressive disease and limited therapeutic options.
• The precise molecular mechanisms driving DHL progression and potential therapeutic vulnerabilities are actively being investigated.

Purpose of the Study:

• To investigate the role of Ca2+/calmodulin-dependent protein kinase II delta (CAMKIIδ) and gamma (CAMKIIγ) in DHL pathogenesis.
• To evaluate the therapeutic potential of inhibiting CAMKIIδ and CAMKIIγ in DHL.

Main Methods:

• Quantitative analysis of CAMKIIδ and CAMKIIγ expression in DHL.
• Assessment of CAMKII isoforms' effect on c-Myc and BCL2 protein levels via phosphorylation.
• In vitro studies using DHL cell lines and in vivo xenograft models to test the anti-tumor efficacy of berbamine (BBM) and its derivative PA4, which inhibit CAMKII.

Main Results:

• CAMKIIδ and CAMKIIγ were found to be highly expressed in DHL.
• Both CAMKII isoforms were shown to stabilize c-Myc by phosphorylating it at Ser62 and to increase BCL2 expression, thereby promoting DHL tumor growth.
• Inhibition of CAMKIIδ and CAMKIIγ by BBM/PA4 resulted in decreased c-Myc and BCL2 protein levels and demonstrated anti-tumor activity in DHL models.

Conclusions:

• CAMKIIδ and CAMKIIγ are critical regulators of DHL tumor development.
• Targeting CAMKIIδ and CAMKIIγ represents a promising therapeutic strategy for double-hit lymphoma.