Calpain-2 inhibition alleviates hypercalcemia-driven multiple myeloma progression

Area of Science:

• Hematology
• Oncology
• Molecular Biology

Background:

• Multiple myeloma (MM) is a plasma cell malignancy.
• Hypercalcemia is a frequent MM complication, but its direct role in disease progression is unclear.
• Elevated calcium can cause severe neurological symptoms in MM patients.

Purpose of the Study:

• To investigate the direct role of hypercalcemia in MM progression.
• To explore the association between calcium, calpain-2 (CAPN2), and MM cell proliferation.
• To evaluate CAPN2 as a therapeutic target in MM.

Main Methods:

• Assessed the effect of high calcium concentrations on MM cell proliferation.
• Measured CAPN2 expression in MM patients and correlated it with prognosis.
• Utilized CAPN2 knockdown and a CAPN2 inhibitor (ALLN) in in vitro and in vivo MM models.
• Investigated the synergistic effects of ALLN with bortezomib and doxorubicin.

Main Results:

• High calcium concentrations promote MM cell proliferation, linked to CAPN2.
• CAPN2 expression is elevated in MM patients and associated with poor prognosis.
• CAPN2 knockdown and ALLN treatment inhibited MM cell proliferation by inducing apoptosis via FN14 upregulation.
• ALLN enhanced MM cell sensitivity to bortezomib and doxorubicin without harming normal cells.

Conclusions:

• CAPN2 plays a crucial role in MM progression and is a potential therapeutic target.
• ALLN demonstrates efficacy in suppressing MM and sensitizing cells to existing treatments.
• This study clarifies the hypercalcemia-CAPN2-proliferation axis in MM, offering new therapeutic avenues.