Fig. 4.

Src regulation of tumor growth and lipid droplet is FABP4-dependent in vitro and in vivo. (a) Lipid staining (left) and quantification (right) in HBEC-C1-PPARγ (upper) and Calu6 (lower) cells. Cells were treated with 5 μM of SU6656 (SU), 20 μM of HTS01037 (HTS) or both for 3 days. (b) In vitro cell growth assay upon Src inhibitor treatment. Cell proliferation (left) and MTT (right) assays showed inhibition of cell proliferation upon SU6656 treatment for 7 days in Calu6. (c-d) In vivo analysis of the xenograft tumors by inhibiting oncogenic Src. Five millions of Calu6 cells were injected into the flank region of athymic nude mice. When tumors were tangible, mice were intraperitoneally administered with vehicle (n = 5) or SU6656 20 mg/kg (n = 7) for 23 days every other day. (c) Tumor growth suppression upon SU6656 treatment. Both tumor volume (left) and tumor weight (right) were measured every other day or at the end of the experiment, respectively. Tumor growth were represented as mean relative tumor size ± SEM. Statistical analysis was determined using 2-way ANOVA. (d) Intratumoral lipid amount and FABP4 protein expression. Intratumoral lipid content (upper) or FABP4 expression (lower) were assayed in the residual tumor tissues at the end of in vivo experiment. Note that a pair of representative figures was shown for lipid staining. Values are mean ± SEM. Statistical significance was assessed using Student's t-test. Asterisks refer to *P ≤ 0∙05; **P ≤ 0∙01; ***P ≤ 0∙001; ****P ≤ 0∙0001 (One-way ANOVA, Tukey's post test (a), Student's t-test (b, c (right) and d) and two-way ANOVA, Sidak's post test (c (left))).