ABSTRACT
[This corrects the article DOI: 10.18632/oncotarget.2152.].
ABSTRACT
BACKGROUND: Osteopontin (OPN) is one of important molecular targets in cancer progression, metastasis as a calcium-binding, extracellular-matrix-associated protein of the small integrin-binding ligand and, N-linked glycoprotein. In the present study, anti-metastatic mechanism of ethanol extracts of Ocimum sanctum (EEOS) was elucidated on OPN enhanced metastasis in NCI-H460 non- small cell lung cancer cells. METHODS: Cell viability was measured by MTT assay. Adhesion and invasion assays were carried out to see that EEOS inhibited cell adhesion and invasion in OPN treated and non-treated NCI-H 460 cells. RT-PCR was used to determine the mRNA levels of uPA, uPAR, and EGFR. RESULTS: EEOS significantly inhibited cell adhesion and invasion in OPN treated and non treated NCI-H460 cells, though EEOS did not show any toxicity up to 200 µg/ml. EEOS effectively attenuated the expression of OPN and CD44 and also OPN activated the expression of CD44 in NCI-H460 cells. In addition, EEOS effectively suppressed the expression of phosphatidylinositide 3-kinases (PI3K) and cyclooxygenase 2 (COX-2) and the phosphorylation of Akt at protein level in OPN treated NCI-H460 cells. Also, EEOS significantly attenuated the expression of urokinase plasminogen activator (uPA), its receptor (uPAR) and epidermal growth factor receptor (EGFR) at mRNA level and reduced vascular endothelial growth factor (VEGF) production and MMP-9 activity in OPN treated NCI-H460 cells. Furthermore, PI3K/Akt inhibitor LY294002 enhanced anti-metastatic potential of EEOS to attenuate the expression of uPA and MMP-9 in OPN treated NCI-H 460 cells. CONCLUSION: Overall, our findings suggest that anti-metastatic mechanism of EEOS is mediated by inhibition of PI3K/Akt in OPN treated NCI-H460 non-small cell lung cancer cells.
Subject(s)
Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Ocimum/chemistry , Osteopontin/genetics , Osteopontin/metabolism , Plant Extracts/pharmacology , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/physiopathology , Cell Adhesion/drug effects , Cell Line, Tumor , Gene Expression Regulation, Plant/drug effects , Humans , Neoplasm Metastasis , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylation/drug effects , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolismABSTRACT
Though tumor necrosis factor related apoptosis inducing ligand (TRAIL) has been used as a potent anticancer agent, TRAIL resistance is a hot-issue in cancer therapy. We investigated the antitumor mechanism of Tanshinone I to sensitize prostate cancer cells to TRAIL. Comibination of Tanshinone I and TRAIL exerted synergistic cytotoxicity, increased cleaved PARP, sub G1 population, the number of TUNELpositive cells, activated caspase 8, 9 and ROS production in PC-3 and DU145 cells. Of note, combination of Tanshinone I and TRAIL enhanced the protein expression of death receptor 5 (DR5) and attenuated anti-apoptotic proteins. RT-PCR and RT-qPCR analyses confirmed that co-treatment of Tanshinone I and TRAIL up-regulated DR5 and microRNA 135a-3p at mRNA level or activity of DR5 promoter and attenuated phosphorylation of extracellular signal regulated kinases in PC-3. Conversely, the silencing of DR5 blocked the increased cytotoxicity, sub G1 population and PARP cleavages induced by co-treatment of Tanshinone I and TRAIL. Interestingly, miR135a-3p mimic enhanced DR5 at mRNA, increased PARP cleavage, Bax and the number of TUNEL positive cells in Tanshinone I and TRAIL cotreated PC-3. Overall, our findings suggest that Tanshinone I enhances TRAIL mediated apoptosis via upregulation of miR135a-3p mediated DR5 in prostate cancer cells as a potent TRAIL sensitizer.
