cardamonin and Triple-Negative-Breast-Neoplasms

Cardamonin, a chalcone isolated from Alpiniae katsumadai, has anti-inflammatory and anti-tumor activities. However, the molecular mechanism by which cardamonin inhibits breast cancer progression largely remains to be determined.. CCK-8 and Hoechst 33258 staining were used to detect cell growth and apoptosis, respectively. HIF-1α driven transcription was measured by luciferase reporter assay. Glucose uptake and lactate content were detected with 2-NBDG and L-Lactate Assay Kit. Cell metabolism assays were performed on Agilent's Seahorse Bioscience XF96 Extracellular Flux Analyzer. Mitochondrial membrane potential was measured with JC-1 probe. DCFH-DA was used to measure ROS level. Protein expression was detected by western blotting assay. Immunohistochemistry was performed to measure the expression of HIF-1α, LDHA and CD31 in tumor tissues.. Cardamonin inhibited growth of the triple negative breast cancer cell line MDA-MB-231 in vitro and in vivo by suppressing HIF-1α mediated cell metabolism. Cardamonin inhibited the expression of HIF-1α at mRNA and protein levels by repressing the mTOR/p70S6K pathway, and subsequently enhanced mitochondrial oxidative phosphorylation and induced reactive oxygen species (ROS) accumulation. We also found that cardamonin inhibited the Nrf2-dependent ROS scavenging system which further increased intracellular ROS levels. Eventually, accumulation of the intracellular ROS induced apoptosis in breast cancer cells. In addition, cardamonin treatment reduced glucose uptake as well as lactic acid production and efflux, suggesting its function in repressing the glycolysis process.. These results reveal novel function of cardamonin in modulating cancer cell metabolism and suppressing breast cancer progression, and suggest its potential for breast cancer treatment.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Growth Processes; Cell Line, Tumor; Chalcones; Female; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Mice; Mitochondria; NF-E2-Related Factor 2; Oxidative Phosphorylation; Reactive Oxygen Species; Ribosomal Protein S6 Kinases, 70-kDa; RNA, Messenger; Signal Transduction; TOR Serine-Threonine Kinases; Triple Negative Breast Neoplasms; Xenograft Model Antitumor Assays

Cardamonin (CD), an active chalconoid, has shown potent anticancer effects in preclinical studies; however, the effect and underlying mechanism of CD for the treatment of triple negative breast cancer (TNBC) is unclear. This study aims to examine the cytotoxic effects of CD and investigate the underlying mechanism in human TNBC cells. The results show that CD exhibits cytotoxicity by inducing apoptosis and cell cycle arrest in TNBC cells via modulation of Bcl-2, Bax, cyt-C, cleaved caspase-3, and PARP. We find that CD significantly increases expression of the epithelial marker E-cadherin, while reciprocally decreasing expression of mesenchymal markers such as snail, slug, and vimentin in BT-549 cells. In parallel with epithelial-mesenchymal transition (EMT) reversal, CD down regulates invasion and migration of BT-549 cells. CD markedly reduces stability and nuclear translocation of β-catenin, accompanied with downregulation of β-catenin target genes. Using the TopFlash luciferase reporter assay, we reveal CD as a specific inhibitor of the Wnt3a-induced signaling. These results suggest the involvement of the Wnt/β-catenin signaling in the CD-induced EMT reversion of BT-549 cells. Notably, CD restores the glycogen synthase kinase-3β (GSK3β) activity, required for β-catenin destruction via the proteasome-mediated system, by inhibiting the phosphorylation of GSK3β by Akt. These occurrences ultimately lead to the blockage of EMT and the invasion of TNBC cells. Further antitumor activity of CD was tested in 4T1 (TNBC cells) induced tumor and it was found that CD significantly inhibited the tumor volume at dose of 5 mg/kg-treated mice. © 2016 BioFactors, 43(2):152-169, 2017.

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Chalcones; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3 beta; Humans; Mice; Neoplasm Invasiveness; Neoplasm Proteins; Triple Negative Breast Neoplasms; Wnt Signaling Pathway; Xenograft Model Antitumor Assays