Tumor protein 53 mutations are enriched in diffuse large B-cell lymphoma with irregular CD19 marker expression

Area of Science:

• Oncology
• Molecular Biology
• Hematology

Background:

• Tumor protein 53 (p53) is crucial for cellular differentiation.
• Mutations in the TP53 gene may correlate with aberrant cell differentiation observed in cancers.
• Diffuse large B cell lymphoma (DLBCL) is a heterogeneous lymphoma with varying differentiation patterns.

Purpose of the Study:

• To investigate the association between TP53 mutations and the expression of B cell lineage markers in DLBCL.
• To determine if TP53 mutations are more prevalent in DLBCL subtypes with irregular differentiation, specifically CD19 negativity.

Main Methods:

• Sequencing of the TP53 gene in 94 DLBCL samples (16 CD19 negative, 78 CD19 positive).
• Analysis of B cell markers, including CD19 and paired box 5 (PAX5), in relation to TP53 mutation status.
• Correlation of TP53 mutation status with patient survival outcomes.

Main Results:

• TP53 mutations were significantly more frequent in CD19 negative DLBCL (81%) compared to CD19 positive DLBCL (21%).
• Mutant TP53 was associated with poorer patient survival.
• Loss of PAX5 expression was more common in CD19 positive DLBCL with mutant TP53 (50%) versus wild-type TP53 (15%).

Conclusions:

• DLBCL lacking CD19 expression is strongly associated with TP53 mutations.
• Irregular B cell marker phenotypes, such as CD19 or PAX5 negativity, are linked to TP53 mutations in DLBCL.
• These findings highlight a potential role for TP53 in regulating B cell differentiation and suggest TP53 mutation status as a prognostic marker in DLBCL.