The IL-17B–IL-17RB signaling pathway is essential for tumorigenic and metastatic abilities of pancreatic cancer cell lines. (A) RT-PCR analysis of IL-17B in pancreatic cancer cell lines. β-actin was used as a loading control. (B) mRNA expression of IL-17B determined by RT-qPCR in CFPAC1 and BxPC3 cells infected with shLacZ or shIL-17RB. (C and D) SACF assay (C) and invasion assay (D) using CFPAC-1 and BxPC3 cells infected with shLacZ or shIL-17B. (E and F) SACF assay (E) and invasion assay (F) using CFPAC-1 and BxPC3 cells supplemented with IgG control, anti–IL-17RB, or anti–IL-17B (1 µg/ml). (G) Tumorigenesis assay of NOD/SCIDγ mice subcutaneously injected with shLacZ-transduced or IL-17B–depleted CFPAC-1 cells. Cell dose: 1 × 10⁶ cells per mouse. Four mice were used for each group. (H) Tumor weight of NOD/SCIDγ mice orthotopically implanted with shLacZ-transduced or IL-17B–depleted CFPAC-1 cells. Cell dose: 2.5 × 10⁵ cells per mouse. Three mice were used for each group. (I) Summary table of lung and liver metastasis derived from orthotopic xenograft. (J) Lung metastasis of NOD/SCIDγ mice intravenously injected with shLacZ-transduced or IL-17B depleted CFPAC-1 cells. Cell dose: 5 × 10⁵ cells per mouse. Four mice were used for each group. (K and L) SACF assay (K) and invasion assay (L) using CFPAC-1 and BxPC3 cells treated with BSA or rIL17B. (M and N) SACF assay (M) and invasion assay (N) using IL-17RB full-length or ΔLBD overexpressing SU.86.86 and HPAC cells treated with BSA or rIL17B. Data shown are means ± SD. *, P < 0.05; **, P < 0.01 (Student’s t test). All experimental data verified in at least two independent experiments.