Sema4D/Plexin-B1 promotes the progression of osteosarcoma cells by activating Pyk2-PI3K-AKT pathway.

Objectives: Osteosarcoma (OS) is one of the two most common malignant bone tumors among children and teens but it is still a rare disorder. Semaphorin 4D (Sema4D) has been reported to play a specific role in human cancers. The aim of this study was to explore the function of Sema4D in the tumorigenesis and development of OS.

Methods: 10 pairs of OS tissues and paracancerous normal tissues from human OS samples and OS cell lines were used. Western blot assay was performed to detect the protein expression of Sema4D, Plexin-B1, and associated proteins of Pyk2-PI3K/AKT pathway. To explore the effect of Sema4D in the progression of OS, we reduced the expression of Sema4D. The effect of Sema4D knockdown on cell proliferation was explored by CCK-8 assay and clone formation assay. The effect of Sema4D knockdown on cell migration and invasion was assessed by Transwell assay.

Results: Sema4D was overexpressed in OS tissues and cell lines. Sema4D knockdown notably suppressed cell proliferation in OS cells. Cell migration and invasion were reduced by Sema4D knockdown. Sema4D/Plexin-B1 facilitated OS, progression by promoting Pyk2-PI3K/AKT pathway.

Conclusion: Sema4D/Plexin-B1 promoted the development of OS so Sema4D might be a potential target of treatment for patients with OS.