Objective      To determine the effect of CXCR4 knockdown by RNA interference on the proliferation and invasion in pancreatic cancer cells.       Methods      Pancreatic cancer cell lines PC-2

PC-3

Miapaca-2

BXPC-3

and PANC-1 were used to screen the cells with high expression of CXCR4 by real-time PCR. RNAi technique was applied to construct the CXCR4 shRNA expression vector. Then the vector was transfected into the cells with highly expressed CXCR4 with the aid of Lipofectamine 2000

and the cells with stable expression were screened with G418.  Real-time PCR and Western blotting were used to observe the inhibitory effect of RNAi on CXCR4 expression. MTT assay was applied to assess the influence of specific CXCR4 shRNA on cell growth. Transwell chamber test was used to observe the cancer cell invasive ability.       Results      Miapaca-2 cells showed significantly high expression of CXCR4. Transfection of specific CXCR4 shRNA into Miapaca-2 cells resulted in a stable

specific and highly-efficient declined expression of CXCR4 (70%) at mRNA and protein levels

and an inhibition in cell proliferation and growth arrest in exponential phase cells (P0.05). Transwell chamber test indicated that the transfection of specific CXCR4 shRNA also led to the decrease of invasive ability of Miapaca-2 cells (P0.05)

even under the stimulation of SDF-1.       Conclusion      CXCR4 shRNA vector is successfully constructed. CXCR4 knockdown inhibits the proliferation

cell tumorigenesis and invasive ability in pancreatic cancer cells.