rottlerin and Mesothelioma

Sphingosine regulates cellular differentiation, cell growth, and apoptosis. The present study aimed at understanding sphingosine-regulated mesothelioma cell proliferation.. Human malignant mesothelioma cells such as NCI-H28, NCI-H2052, NCI-H2452, and MSTO-211H cells were cultured. The siRNA to silence the protein kinase C (PKC)-δ-targeted gene was constructed and transfected into cells. MTT assay, cell cycle analysis using a flow cytometry, and cell-free PKC-δ assay were carried out.. For all the cell types sphingosine inhibited cell growth in a concentration (1-100 µM)-dependent manner. The sphingosine effect was not prevented by rottlerin, an inhibitor of protein kinase C-δ (PKC-δ); conversely, rottlerin further enhanced the sphingosine effect or rottlerin suppressed mesothelioma cell growth without sphingosine. In the cell-free PKC assay, sphingosine attenuated PKC-δ activity. Knocking-down PKC-δ induced cell cycle arrest at the G0/G1 phase and inhibited cell growth.. The results of the present study show that sphingosine suppressed mesothelioma cell proliferation by inhibiting PKC-δ, to induce cell cycle arrest at the G0/G1 phase.

Topics: Acetophenones; Benzopyrans; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; G1 Phase; Humans; Mesothelioma; Protein Kinase C-delta; Resting Phase, Cell Cycle; RNA Interference; RNA, Small Interfering; Sphingosine