Amyloidogenic light chains impair plasma cell survival.

Area of Science:

• Hematology
• Oncology
• Molecular Biology

Background:

• Systemic light chain amyloidosis (AL) is a plasma cell disorder caused by misfolded immunoglobulin light chains (LC).
• Lack of suitable in vitro models has limited understanding of AL disease mechanisms.

Purpose of the Study:

• To establish and characterize AL LC-producing plasma cell lines.
• To investigate the unique biology and cellular pathways of the amyloidogenic clone in AL amyloidosis.

Main Methods:

• Generation of AL LC-producing cell lines using lentiviral vectors.
• Comparative analysis of AL LC-producing cells versus multiple myeloma LC-producing cells.
• RNA sequencing to analyze cellular pathways and stress responses.

Main Results:

• AL LC-producing cell lines exhibited decreased proliferation, cell cycle arrest, and increased apoptosis and autophagy.
• RNA sequencing revealed heightened mitochondrial oxidative stress and reduced Myc and cholesterol pathway activity in AL cells.
• Constitutive expression of amyloidogenic LC induces intracellular toxicity, altering neoplastic plasma cell behavior.

Conclusions:

• Established AL LC-producing cell lines provide a valuable in vitro model for studying AL amyloidosis.
• Amyloidogenic LC expression alters plasma cell behavior, leading to intracellular toxicity and potentially explaining differences from myeloma.
• Findings pave the way for further research into unique AL cellular pathways and the development of targeted therapies.