Dihydrotanshinone-I and Colonic-Neoplasms

Cryptotanshinone (CPT) and dihydrotanshinone (DHT) are diterpenoid anthraquinone compounds extracted from traditional Chinese herbal medicine (TCM). Recent studies have shown that CPT regulates the signal transduction pathways via microRNA (miRNA) alterations. However, few studies have investigated the role of DHT in miRNA alterations affecting cell-signaling pathways. This study aimed to investigate the miRNA alterations and post-transcriptional regulation activities of DHT in comparison to CPT.. HepG2 and HT-29 cells were treated with DHT or CPT for 72 h. MiRNA, transcription factor encoding mRNA, and downstream gene expression were determined using real-time quantitative PCR. Protein expression was analyzed using western blotting.. The results revealed that CPT and DHT targeted cell proliferation and apoptosis signaling pathways via miR-15a-5p, miR-27a-5p, miR-100-5p, and miR-200a-5p alterations.In silico target predictions showed that downregulation of epidermal growth factor receptor (EGFR) mRNA expression by DHT might also suppress the expression of STAT family proteins and lead to anti-proliferation effects. We also found that, compared to CPT, DHT might possess higher potency in cell growth regulation via multi-miRNA and transcription factor alterations.. This study revealed that CPT and DHT targeted cell proliferation and apoptosis signaling pathways via alterations in miRNAs and transcription factors. In addition, the findings of this study suggest that DHT is more potent than CPT in cancer chemopreventive activities. Therefore, DHT at a low dose is a TCM compound with less toxic side effects and may contribute to the development of natural medicine as a potential cancer chemopreventive agent.

Topics: Anticarcinogenic Agents; Antineoplastic Agents, Phytogenic; Apoptosis; Apoptosis Regulatory Proteins; Cell Cycle Proteins; Cell Proliferation; Colonic Neoplasms; Furans; Gene Expression Regulation, Neoplastic; Gene Regulatory Networks; Hep G2 Cells; HT29 Cells; Humans; Liver Neoplasms; MicroRNAs; Phenanthrenes; Quinones; Signal Transduction; Transcription Factors; Transcriptome

Metabolic reprogramming and hypoxia contribute to the resistance of conventional chemotherapeutic drugs in kinds of cancers. In this study, we investigated the effect of dihydrotanshinone I (DHTS) on reversing dysregulated metabolism of glucose and fatty acid in colon cancer and elucidated its mechanism of action.. Cell viability was determined by MTT assay. Oxidative phosphorylation, glycolysis, and mitochondrial fuel oxidation were assessed by Mito stress test, glycolysis stress test, and mito fuel flex test, respectively. Anti-cancer activity of DHTS in vivo was evaluated in Colon cancer xenograft. Hexokinase activity and free fatty acid (FFA) content were assessed using respective Commercial kits. Gene expression patterns were determined by performing DNA microarray analysis and real-time PCR. Protein expression was assessed using immunoblotting and immunohistochemistry.. DHTS showed similar cytotoxicity against colon cancer cells under hypoxia and normoxia. DHTS decreased the efficiency of glucose and FA as mitochondrial fuels in HCT116 cells, which efficiently reversed by VO-OHpic trihydrate. DHTS reduced hexokinase activity and free fatty acid (FFA) content in tumor tissue of xenograft model of colon cancer. Gene expression patterns in metabolic pathways were dramatically differential between model and treatment group. Increases in PTEN and a substantial decrease in the expression of SIRT3, HIF1α, p-AKT, HKII, p-MTOR, RHEB, and p-ACC were detected.. DHTS reversed metabolic reprogramming in colon cancer through PTEN/AKT/HIF1α-mediated signal pathway.. The study is the first to report the reverse of metabolic reprogramming by DHTS in colon cancer. Meantime, SIRT3/PTEN/AKT/HIF1α mediated signal pathway plays a critical role during this process.

Topics: Animals; Apoptosis; Cell Proliferation; Colonic Neoplasms; Furans; Gene Expression Regulation, Neoplastic; Glycolysis; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Male; Mice; Mice, Nude; Mitochondria; Oxidative Phosphorylation; Phenanthrenes; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Quinones; Signal Transduction; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

The therapeutic potential of various tanshinones was examined and compared for their anti-cancer activities on colon cancer cells. The role of ROS generation in the pro-apoptotic activity of dihydrotanshinone (DHTS) was further studied.. Cell viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis and poly-ADP-ribose-polymerase (PARP) cleavage were respectively measured by flow cytometer and Western blot. Changes of mitochondrial membrane potential (MMP), mitochondrial ROS (mitoROS) and total ROS were determined by confocal system under an inverted microscope.. Among the different tanshinones examined, DHTS produced the most potent anti-cancer effect. DHTS induced a selective cytotoxicity and apoptosis in both HCT116 p53(-/-) and HCT116 p53(+/+) colon cancer cells. A time- and concentration-dependent PARP cleavage further confirmed the apoptotic activity. In this regard, it was found DHTS provoked mitochondrial dysfunction in the early stage by decreasing MMP and mitoROS levels. This was followed by a time-dependent increase in intracellular ROS generation. Pretreatment with N-acetyl-l-cysteine (NAC) or catalase-PEG, the free radical scavengers, reduced apoptotic cell death. From these findings, it seems that leakage of ROS from mitochondria into cytosol by DHTS represents the major contributory factor leading to cell death in colon cancer cells.. We report for the first time that DHTS induces apoptosis in colon cancer cells through a p53-independent pathway. Disturbance of ROS generation at the oxidative phosphorylation (OXPHOS) complex in mitochondria followed by the decrease of MMP and increase of intracellular ROS accumulation are suggested to be involved in the pro-apoptotic activity of DHTS.

Topics: Apoptosis; Blotting, Western; Caco-2 Cells; Cell Survival; Colonic Neoplasms; Flow Cytometry; Free Radical Scavengers; Furans; HCT116 Cells; Humans; Membrane Potential, Mitochondrial; Microscopy, Confocal; Oxidative Phosphorylation; Phenanthrenes; Poly(ADP-ribose) Polymerases; Quinones; Reactive Oxygen Species; Time Factors; Tumor Suppressor Protein p53