Objective: To explore the role of PTEN gene in the regulation of tissue factor (TF) expression in human neuroblastoma cells.
Methods: Expression of PTEN or TF was determined by Western blotting. Transcription of TF was examined by RT-PCR. PTEN gene expressing vector pCMV-PTEN was transfected with Lipofectamine2000. Phosphorylation of AKT was inhibited by LY294002 and then examined by Western blotting.
Results: Human neuroblastoma cell line SK-N-SH was PTEN-positive and expressed low level TF, whereas an other neuroblastoma cell line SK-N-MC was PTEN-negative but expressed high level TF. TF level was downregulated in SK-N-MC cells by enforced expression of PTEN in a dose dependent manner. Inhibition of TF was achieved along with inactivation of AKT. Furthermore treatment with PI3K/AKT inhibitor LY294002 also resulted in decrease of TF expression in a dose-dependent manner.
Conclusion: Expression of TF is inhibited by PTEN gene via inactivating PI3K/AKT pathway, loss of PTEN might be the explanation of aberrant high-level TF in human neuroblastoma. It may be at least one of the mechanisms by which loss of PTEN expression confers to cancer progression.