CHI3L1 is upregulated in mammary tumor-bearing mice. (A) Serum was collected from normal and 5-week tumor-bearing mice and analyzed for CHI3L1 expression by ELISA. (B) CHI3L1 expression in DA-3 mammary tumor cells was localized by immunofluorescence using confocal microscopy, scale bar = 20 μM. (C) Purified total RNA from splenocytes of normal and 5-week DA-3 tumor bearers was used to measure expression of CHI3L1 by qRT-PCR. (D–E) Purified myeloid derived cells (D) or macrophages (E) were cultured overnight and cell-free supernatants were analyzed for CHI3L1 expression by ELISA. (F) Purified macrophages from normal and 5-week DA-3 tumor bearers were examined by immunolocalization of CHI3L1 expression and visualized by confocal microscopy, scale bar = 20 μM. For all experiments, N = 8 mice/group, *p<0.0005, Student's t-test. 159×144mm (300 × 300 DPI)