Bolin Chen, Lin Wu, Juan Du

Thoracic Medicine Department 2, Hunan Cancer Hospital, Changsha.

Objective：Bioinformaticsanalysis combined with metastasis-related genes microarray array showed thatosteopontin could be important target genes of miR-29b. Method：Theexpression of miR-29b was down regulated in esophageal cancer tissues comparedto the normal tissues. Clinicopathological analysis showed that miR-29b hadsignificant negative correlation with lymphatic metastasis. High-invasion (OE19-H)and low-invasion (OE19 -L) cell sublines from OE19 cells were created by usingthe repeated transwell assay aimed to assess the effect of miR-29b onbiological behavior of esophageal cancer cells. Result：Thegain-of-function studies that raised miR-29b expression showed reductions incell proliferation，invasionand migration. In contrasts, loss-of-function studies that reduced miR-29bpromoted proliferation, invasion and migration. Nude mice with xenograft modelsof esophageal cancer cells confirmed that miR-29b inhibited lung cancermetastasis in vivo. Furthermore, the dual-luciferase reporter assaydemonstrated that miR-29b inhibited the expression of the luciferase genecontaining the 3′-UTRs of osteopontin mRNA. Western blotting and Q-PCRindicated that miR-29b down-regulated the expression of osteopontin at theprotein and mRNA levels. Taken together，ourresults demonstrate that miR-29b serves as a tumor metastasis suppressor, whichsuppresses esophageal cancer cell metastasis by directly inhibiting osteopontinexpression. Conclusion：Theresults show that miR-29b may be a novel therapeutic candidate target to slowesophageal cancer metastasis.

Key Words：miR29b  esophageal cancer  osteopontin