S-phase kinase protein 2 is an attractive therapeutic target in a subset of diffuse large B-cell lymphoma

Area of Science:

• Oncology
• Cell Biology
• Biochemistry

Background:

• S-phase kinase protein 2 (SKP2) is an F-box protein involved in cell-cycle regulation through the degradation of proteins like p27Kip1.
• SKP2 overexpression is common in cancers and linked to oncogenesis, but its role in diffuse large B-cell lymphoma (DLBCL) remains unclear.

Purpose of the Study:

• To investigate the role of SKP2 and the ubiquitin-proteasome pathway in DLBCL.
• To determine the therapeutic potential of targeting SKP2 in DLBCL.

Main Methods:

• Immunohistochemistry was used to assess SKP2 and p27Kip1 levels in 301 DLBCL patient samples.
• DLBCL cell lines were treated with bortezomib or SKP2-specific siRNA.
• Apoptosis, cell proliferation (Ki-67), and protein expression (XIAP, cIAP1, survivin) were analyzed.

Main Results:

• SKP2 was detected in 41.6% of DLBCL tumors and inversely correlated with p27Kip1.
• High SKP2/low p27Kip1 correlated with increased proliferation (Ki-67) and germinal center B-cell phenotype.
• Bortezomib or SKP2 siRNA treatment reduced SKP2, increased p27Kip1, suppressed growth, and induced apoptosis via the mitochondrial pathway and caspase activation.
• Bortezomib treatment also downregulated XIAP, cIAP1, and survivin.

Conclusions:

• SKP2 is implicated in DLBCL pathogenesis and is associated with aggressive disease features.
• The ubiquitin-proteasome pathway, particularly SKP2, represents a potential therapeutic target for DLBCL.
• Bortezomib demonstrates efficacy in DLBCL by inducing apoptosis through multiple pathways.