Coculture with fibroblasts promoted cell proliferation and enhanced the mTOR/S6 pathway. (A) Primary fibroblasts were obtained from mice spleen via centrifugation. FRCs were cocultured with DLBCL cells in a transwell coculture system. (B) DB or A20 cells were cocultured with FRCs for indicated days at various ratios. The number of DB cells was recorded by cell counting. (C) In a serum-free medium, the number of DB cells, with or without the coculture with FRCs, was determined by cell counting. (D) A schematic illustration of animal models. (E) Tumor volume was measured every day once the tumors became palpable. (F) Mice were euthanized on day 15, and tumors were dissected and weighed. (G) A20 cells were cocultured with FRCs using the transwell coculture system for 24 hours before RNA sequencing (RNA-seq) sample preparation. GO enrichment for upregulated genes of “FRC cocultured with A20” vs A20. The yellow-green color scale corresponds to the enrichment significance of the genes. Dot size is proportional to the number of genes annotated to the corresponding categories. P values are calculated by Fisher exact test. (H) A20 cells were cocultured with FRCs using the transwell coculture system for 24 hours before RNA-seq sample preparation. Network of “FRC cocultured with A20” upregulated genes and enriched concepts. Different colors represent various categories, and the size of the dots corresponds to the number of genes linked to each category. DMEM, Dulbecco modified Eagle medium; FBS, fetal bovine serum.