COMMD3 Regulates Copper Metabolism via the ATOX1-ATP7A-LOX Axis to Promote Multiple Myeloma Progression

Multiple myeloma (MM) is a hematologic malignancy characterized by the clonal proliferation of plasma cells, with extramedullary myeloma (EMM) being an aggressive form involving malignant infiltration beyond the bone marrow. Copper metabolism is essential for tumor proliferation and metastasis, with copper metabolism MURR1 domain (COMMD) proteins regulating these processes and maintaining copper homeostasis. Dysregulated copper homeostasis contributes to cancer progression, including MM, with elevated copper levels linked to disease aggressiveness and poor prognosis. This study investigates the role of the COMMD3 in mediating MM cell progression, particularly its influence on copper metabolism.

This study highlights the pivotal role of COMMD3 in MM progression, particularly via the ATOX1-ATP7A-LOX axis. These findings provide insights into EMM mechanisms and position COMMD3 as a potential therapeutic target. Future research is needed to validate these findings in larger clinical cohorts and to unravel the precise molecular interactions between COMMD3 and copper metabolism proteins.

Comprehensive bioinformatics analyses were conducted on bone marrow and extramedullary samples to determine the expression of COMMD3, which was validated through in vitro and in vivo functional assays. The MM cell lines RPMI8226 and MM1S underwent lentiviral transfection for COMMD3 overexpression and knockdown. RNA sequencing was conducted on COMMD3 knockdown cells to identify differentially expressed genes. Functional assays measured cell proliferation, migration, apoptosis, and copper metabolism, with a non-obese diabetic severe combined immune-deficiency gamma (NSG) mouse xenograft model providing in vivo validation.

Elevated COMMD3 expression was correlated with extramedullary myeloma and poor prognosis in MM patients. COMMD3 promoted MM cell proliferation and migration, modulating intracellular copper levels, likely through the ATOX1-ATP7A-LOX copper-metabolism-related pathway. High ATOX1 expression was correlated with worse outcomes, and ATOX1 inhibition abolished COMMD3's effects. Conclusions: This study highlights the pivotal role of COMMD3 in MM progression, particularly via the ATOX1-ATP7A-LOX axis. These findings provide insights into EMM mechanisms and position COMMD3 as a potential therapeutic target. Future research is needed to validate these findings in larger clinical cohorts and to unravel the precise molecular interactions between COMMD3 and copper metabolism proteins.