CyclinD1 expression is associated with the sensitivity of pancreatic cancer cells to Delta-24-RGD (D-24-RGD). (A) Western blotting assay. The expression of the major components in p16/RB pathways, including p16, RB, Cyclin D1, and CDk4 were analyzed with western blotting. (B) The relative expression level of Cyclin D1 in resistant and sensitive pancreatic cell lines was analyzed using the ratio of the density of Cyclin D1 over beta-Actin. (C) The correlation of Cyclin D1 expression with cells’ sensitivity was analyzed with Pearson correlation. (D) D-24-RGD virus replication. D-24-RGD virus replications in the cells after infection were analyzed using PCR-based assay to check virus copy number in BxPC3, MiaPaCa2 and MDA-PATC53 cells as described in the method section. NS, not significant; *, p<0.05; **, p<0.01, ***, p<0.001.