Establishment and characterization of a novel ‘double‐hit’ follicular lymphoma cell line, FL‐SJC

About 5 per cent of follicular lymphoma (FL) cases are double‐hit (DH) lymphomas. Double‐hit follicular lymphoma (DHFL) cell lines can improve our understanding and drug development on FL. But there are only few DHFL cell lines. Here, we established a new MYC/BCL2 DHFL cell line, FL‐SJC. The cells were obtained from the hydrothorax of a patient with MYC/BCL2 DHFL and cultured for 140 passages in vitro. FL‐SJC cells demonstrated CD19(++), CD20(+), CD22(++), HLA‐DR(+), CD10(+), CD38(+), Lambda(+) CD23(‐), CD5(‐) and Kappa(‐). The chromosome karyotypic analysis confirmed the co‐existence of t(8;22)(q24;q11) and t(14;18)(q32;q21), as well as additional abnormalities involving chromosomes 2 and 3. Fluorescence in situ hybridization analysis (FISH) showed IGH/BCL2 fusion gene and the MYC rearrangement. In addition, the FL‐SJC cells displayed KMT2D/MLL2 and CREBBP gene mutations. After subcutaneous inoculation of FL‐SJC cells, the SCID mice developed solid tumour masses within 6‐8 weeks. FL‐SJC cells were proven to be free of Epstein‐Barr (EB) virus infection and be multidrug‐resistant. In a conclusion, the FL‐SJC cell line has been identified as a novel MYC/BCL2 double‐hit follicular lymphoma that can be used as a potentially available tool for the clinical and basic research, together with the drug development for MYC/BCL2 DHFL.