TSPAN1 promotes human pancreatic cancer cells proliferation by modulating CDK1 via Akt

Background: To explore the potential therapeutic target to treat pancreatic cancers, Tspan1 was detected in human pancreatic cancer tissue and human pancreatic ductal adenocarcinoma cells and functional role of Tspan1 on proliferation was explored and the mechanism was investigated. Materials and Methods: Tspan1 in PCC tissue and PDAC cell lines was measured by qRT-PCR and Western blot. Tspan1 was knock-downed and over-expressed in cells via transfection with Tspan1-siRNA and pLNCX-TSPAN1-cDNA, cell survival, proliferation and cell cycle were measured with MTT, Alamar blue and Flow Cytometry assay. The mRNA and protein expression were assessed by qRT-PCR and Western blotting. The expression of PI3K, Akt and p-Akt were detected, and CDK1 siRNA and specific inhibitor of Akt were used to explore the mechanism of TSPAN1 promoting PDAC cells proliferation.  Results: Tspan1 expression in PCC tissue and PDAC cells was increased. Transfection of siRNA targeting Tspan1 in BxPC3 and PNAC-1 cells obviously decreased cell proliferation and down-regulated CDK1 expression. Consistently, both cell proliferation and CDK1 expression in BxPC3 and PNAC-1 cells were up-regulated with pLNCX-TSPAN1-cDNA transfection. Cell cycle analysis showed that after knockdown of Tspan1 the G2/M phase ratio was increased to cause mitosis arrest, and TSPAN1 overexpression caused cell cycle transition from G2 to M phase to promote cell proliferation. And these were dependent on the modulation of CDK1 expression via Akt. Conclusion: Tspan1 up-regulates CDK1 expression via activating Akt to promote human PCC cell proliferation and silencing of Tspan1 may be a potential therapeutic target to treat pancreatic cancers.