beta-escin and Lung-Neoplasms

Lung cancer is the most common and lethal cancer worldwide, yet there are no adequate and novel medications to control this illness. Previous reports suggested the potential of protein kinases to target lung cancer by regulating autophagy. This study establishes the role of aescin, a triterpenoid saponin, in targeting protein kinases responsible for lung cancer proliferation and mobility. The experimental data revealed that aescin significantly impedes lung cancer cell proliferation by downregulating protein kinases such as AKT, mTOR, MEK, and ERK. Downregulation of AKT-mTOR may promote a string of events inducing cytotoxic autophagy-mediated apoptosis in the presence of aescin. Besides, aescin decreases mobility and invasion by downregulating HIF-1α and VEGF gene expressions. Moreover, it successfully monitors EGFR gene expression, improves lung histology, and regulates biochemical parameters in a pre-clinical DEN-induced lung cancer model. Aescin was observed to be safe and non-toxic in both in silico toxicity predictions and ex vivo erythrocyte fragility assays. Hence, this study elucidates the molecular mechanism of aescin in targeting protein kinases and suggests that it could be a safer and more viable therapeutic agent for lung cancer treatment.

Topics: Apoptosis; Autophagy; Cell Line, Tumor; Escin; Humans; Lung; Lung Neoplasms; Proto-Oncogene Proteins c-akt; Saponins; TOR Serine-Threonine Kinases; Triterpenes

Lung cancer is the leading cause of cancer-related deaths. β-Escin, a triterpene saponin isolated from horse chestnut seeds, was tested for inhibition of lung adenoma and adenocarcinoma induced by the tobacco carcinogen 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in female A/J mice; and its possible mode of action was evaluated using the H460 human lung cancer cell line. At 6 weeks of age, 35 mice were fed AIN-76A-modified diet, and one week later, lung tumors were induced with a single intraperitoneal (i.p.) injection of 10 μmol NNK/mouse. Three weeks after the NNK treatment, groups of mice were fed either control or experimental diets containing 500 ppm for 20 weeks (10 control, 5 β-escin) or 36 weeks (15 control, 5 β-escin) and evaluated for lung tumor via histopathologic methods. Administration of 500 ppm β-escin significantly suppressed lung tumor (adenoma + adenocarcinoma) formation by more than 40% (P < 0.0015) at 20 weeks and by 53.3% (P < 0.0001) at 37 weeks. β-Escin inhibited NNK-induced lung adenocarcinoma formation by 65% (P < 0.001) at 20 weeks and by 53% (P < 0.0001) at 37 weeks. Immunohistochemical analysis revealed that lung tumors from mice exposed to β-escin showed significantly reduced aldehyde dehydrogenase (ALDH)1A1 and phospho-Akt (p-Akt) expression when compared with those in mice fed control diet. Aldefluor assay for ALDH revealed that among H460 lung cancer cells treated with different concentrations of β-escin (0-40 μmol/L), the subpopulation of cells with elevated ALDH activity was inhibited significantly. Our findings suggest that β-escin inhibits tobacco carcinogen-induced lung tumor formation by modulating ALDH1A1-positive cells and RhoA/Rock signaling.

Topics: Adenocarcinoma; Adenoma; Aldehyde Dehydrogenase; Aldehyde Dehydrogenase 1 Family; Animals; Carcinogenesis; Cell Line, Tumor; Disease Progression; Escin; Female; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Mice; Neoplasm Transplantation; Nicotiana; Nitrosamines; Plant Extracts; Real-Time Polymerase Chain Reaction; Retinal Dehydrogenase; rho GTP-Binding Proteins; rho-Associated Kinases; rhoA GTP-Binding Protein

β-escin, a triterpene saponin, is one of the major active compounds extracted from horse chestnut (Aesculus hippocastanum) seed. Previous work has found that β-escin sodium has antiinflammatory and antitumor effects. In the present study, we investigated its effect on cell proliferation and inducible nitric-oxide synthase (iNOS) expression in human lung carcinoma A549 cells. β-escin sodium (5-40 µg/mL) inhibited cytokine mixture (CM)-induced nitric oxide (NO) production in A549 cells by reducing the expression of iNOS. β-escin sodium suppressed phosphorylation and nuclear translocation of STAT1 (Tyr701) and STAT3 (Tyr705) induced by CM but did not affect the activation of c-Jun and NF-κB. β-escin sodium inhibited the activation of protein tyrosine kinase JAK2. Pervanadate treatment reversed the β-escin sodium-induced downregulation of STAT3 and STAT1. β-escin sodium treatment enhanced an activating phosphorylation of the phosphatase SHP2. Small interfering RNA-mediated knockdown of SHP2 inhibited β-escin sodium-induced phospho-STAT dephosphorylation. Moreover β-escin sodium reduced the activation of p38 MAPK. Finally, β-escin sodium inhibited the proliferation of A549 cells, did not change the cell membrane's permeability, nuclear morphology and size and the mitochondria's transmembrane potential of A549 cells. Taken together, these results demonstrate that β-escin sodium could downregulate iNOS expression through inhibiting JAK/STAT signaling and p38 MAPK activation in A549 cells. β-escin sodium has a marked antiproliferative effect on A549 cells at least in part by inhibiting the JAK/STAT signaling pathway, but not by a cytotoxic effect. β-escin sodium would be useful as a chemopreventive agent or a therapeutic against inflammatory-associated tumor. © 2011 Wiley Periodicals, Inc.

Topics: Active Transport, Cell Nucleus; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Enzyme Activation; Enzyme Inhibitors; Escin; Humans; Janus Kinases; JNK Mitogen-Activated Protein Kinases; Lung; Lung Neoplasms; MAP Kinase Signaling System; NF-kappa B; Nitric Oxide Synthase Type II; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Protein Tyrosine Phosphatase, Non-Receptor Type 11; RNA Interference; RNA, Small Interfering; STAT Transcription Factors; Vanadates