Targeted inhibition of chondroitin polymerizing factor suppresses CD5+ diffuse large B-cell lymphoma progression through the PI3K/AKT signaling and RhoA/ROCK axis

Introduction: Diffuse large B-cell lymphoma (DLBCL), particularly the cluster of differentiation (CD) 5+ subtype, presents unique challenges due to its high aggressiveness and limited therapeutic responsiveness. Objective: This study focuses on chondroitin polymerizing factor (CHPF), a key enzyme in chondroitin sulfate biosynthesis, which has been observed to be upregulated in CD5+ DLBCL tissues and cell lines. Methods: CHPF expression in DLBCL and normal tissues was compared using tissue microarrays and immunohistochemical analysis. The effects of CHPF knockdown on lymphoma cell proliferation, migration, apoptosis, and the cell cycle were evaluated in vitro using human lymphoma cell lines. In addition, a xenograft mouse model was employed to assess the impact of CHPF knockdown on in vivo tumor growth. Signaling pathways regulated by CHPF, particularly the phosphoinositide 3-kinases (PI3K)/protein kinase B (AKT) pathway, were identified through KEGG pathway enrichment analysis. The interaction between CHPF and Ras homolog family member A (RhoA) proteins was investigated using a PMSCV-HA-CHPF overexpression plasmid. Results: A significantly elevated level of CHPF was observed in DLBCL specimens compared to normal lymphoid tissue, especially in CD5+ cases. CHPF knockdown markedly suppressed lymphoma cell growth and motility, enhanced apoptotic signaling, and induced cell cycle arrest. In vivo, CHPF knockdown restricted lymphoma progression in the xenograft mouse model. Furthermore, CHPF was found to activate the PI3K/AKT signaling pathway and interact with the RhoA protein. Conclusion: CHPF plays a pivotal role in DLBCL progression by modulating PI3K/AKT signaling pathways. Targeting CHPF may offer a novel therapeutic approach for treating DLBCL.