Lowering Levels of cFLIP Expression Could Improve Extrinsic Apoptosis in DLCBL
Key Takeaways
- High expressions of CFLAR impact overall survival (OS): Patients with diffuse large B-cell lymphoma (DLBCL) who had higher expressions of CFLAR experienced a shorter OS than patients with low expressions of CFLAR.
- High expressions of the gene cFLIP lead to the development of DLCBL cells: In a genetically engineered mouse model, cFLIP deletion led to fewer B cells, indicating that cFLIP supports the growth of cancerous cells and tumors.
- Expressions of cFLIP prevent extrinsic cell death in DLCBL: The deletion of cFLIP in activated B-cell (ABC)-DLCBL made cells more sensitive to induced apoptosis, suggesting that cFLIP protects cancerous cells from cell death.
Apoptosis evasion is a persistent challenge in treating patients with DLBCL. This study used an autochthonous mouse model to assess the effect of cFLIP deletion on extrinsic apoptosis.
At the beginning of the study, researchers observed the expression levels of CFLAR, the gene that encodes cFLIP, in 135 patients with DLBCL. Sixty percent of these patients had elevated expressions of CFLAR, and they experienced a shorter OS than patients with low CFLAR expression.
The Effects of cFLIP in Mice
This study used an autochthonous mouse model to study how cFLIP expression affects the development of B cells in DLBCL. It was observed that CFLAR deletion led to a reduction of B-cell activation, even in mice where cancer-driving genes such as Myd88 and BCL2 were present.
Additionally, CFLAR deletion prevented tumor growth in the mouse model. This data indicates that cFLIP is essential to lymphoma development and its deletion could deletion could help maintain cell death, restrict tumor development, and prevent the expansion of Myd88 and BC12.
Translating the Findings onto Human Cells
The second part of this study observed the dependence of human DLBCL cells on cFLIP, particularly on the ABC and germinal center B-cell (GCB) subsets. Researchers found that ABC cells had a higher survival dependence on cFLIP than GCB cells. Furthermore, cFLIP deletion made ABC cells susceptible to induced apoptosis but had no impact on GCB cells.
In addition to inhibiting cell death, high expressions of cFLIP were found to suppress inflammatory gene expression in ABC cells, which allows cancerous cells to avoid detection by the immune system. Therefore, cFLIP deletion could improve the immunogenicity of DLBCL cells.
Clinical Implications
The findings from this study highlight how cFLIP expression assists in the development and resilience of cancerous DLCBL cells. The authors said, “These findings identify cFLIP as a novel vulnerability in ABC-DLCBL.” The data show that designing cFLIP inhibitors for treating patients with ABC-DLCBL can help improve cell death, leading to better patient outcomes.
Reference
Bariboloka KT, Serrano-Saenz S, Savcigil DP, et al. Expression of cFLIP in B cells is essential for diffuse large B-cell lymphoma pathogenesis. Blood. 2026. doi:10.1182/blood.2026033320
