Axes of biological variation in diffuse large B cell lymphoma

Area of Science:

• Oncology
• Genomics
• Immunology

Background:

• Diffuse large B cell lymphoma (DLBCL) subtypes are currently defined by bulk tumor analysis.
• Understanding the heterogeneity within DLBCL is crucial for targeted therapies.

Purpose of the Study:

• To explore the biology of DLBCL subtypes using single-cell RNA and ATAC sequencing.
• To identify distinct genetic and gene expression signatures within DLBCL tumors.
• To correlate these signatures with patient survival and therapeutic response.

Main Methods:

• Single-cell RNA sequencing and ATAC sequencing were performed on 103 DLBCL biopsies.
• Malignant B cells were identified using non-diploid DNA copy number profiles.
• Gene expression signatures for DLBCL genetic subtypes were developed and validated.

Main Results:

• Distinct genetic and gene expression signatures for DLBCL subtypes were identified, highlighting their unique biological characteristics.
• Genetic subclones within biopsies showed distinct biological themes related to B cell differentiation, proliferation, and growth.
• REL amplification was identified as a mechanism hindering memory B cell differentiation.
• Subtype signatures and biological themes independently varied, influencing transcription factor networks and survival outcomes.

Conclusions:

• Single-cell analysis provides a comprehensive view of intra- and inter-tumoral biological variation in DLBCL.
• This resource facilitates a deeper understanding of DLBCL pathogenesis and treatment strategies.
• Distinct molecular features identified are associated with chemotherapy response and patient survival.