RESUMO
Cepharanthine, a biscoclaurine alkaloid isolated from the roots of Stephania cephalantha Hayata, has been reported to demonstrate antitumor activity across multiple cancer types; however, the mechanisms are still under investigation. High transcriptional responses by both the Hedgehog and Wnt pathways are frequently associated with specific human cancers, including liver cancer. To investigate whether these signaling pathways are involved in the pharmaceutical action of cepharanthine, we investigated Hedgehog and Wnt signaling in models of liver cancer treated with a semisynthetic cepharanthine derivative, cepharanthine hydrochloride (CH), in vitro and in vivo. By using MTT cytotoxic, scratch, Transwell, colony formation and flow cytometry assays, the pharmaceutical effect of CH was assessed. The compound was found to inhibit cellular proliferation and invasion, and promote apoptosis. Subsequent mechanistic investigations revealed that CH suppressed the Hedgehog/Gli1 signaling pathway by inhibiting Gli1 transcription and its transcriptional activity. CH also inhibited Wnt/ßcatenin signaling, and the pathway was found to be an upstream regulator of Hedgehog signaling in CHtreated liver cancer cells. Finally, the antitumor effects of CH were demonstrated in an in vivo xenograft tumor model. Immunohistochemical analysis indicated that Gli1 protein levels were diminished in CHtreated xenografts, compared with that noted in the controls. In summary, our results highlight a novel pharmaceutical antitumor mechanism of cepharanthine and provide support for CH as a clinical therapy for refractory liver cancer and other Wnt/Hedgehogdriven cancers.
Assuntos
Proteínas Hedgehog , Neoplasias Hepáticas , Apoptose , Benzilisoquinolinas , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Via de Sinalização Wnt , beta CateninaRESUMO
BACKGROUND: A number of studies have found that metabolic disorders are the characteristic manifestations of tumor cells. However, the effects of hypoxic environment on mitochondrial function and glucose metabolism of tumor cells were still unclear. The study wanted to explore the regulatory mechanism of hypoxic environment on mitochondrial function and metabolism in gastric cancer cells. METHODS: The animal model of gastric cancer and MKN45 were treated in a hypoxic environment. Mitochondrial membrane potential and reactive oxygen species (ROS) levels were analyzed by flow cytometry, qPCR was used to detect the expression levels of glycose metabolism key enzymes, damage repair genes and mitochondrial DNA (mtDNA) copy numbers in gastric cancer. RESULTS: Compared with 2,000 m normal gastric cancer tissue, the decreased of mitochondrial membrane potential and the production of ROS reduced, the expressions of glucose metabolism genes [the M1 isoform of Hexokinase (HK1), pyruvate kinase (PKM), Succinate dehydrogenase (SDHA), Glucose-6-phosphate dehydrogenase (G6PD)], homologous recombination repair gene (RAD51) and repair DNA double-stranded broken gene (ASTCT2) increased, and aerobic respiration reduced in gastric cancer cells. In the hypoxic environment, the decreased of mitochondrial membrane potential reduced, the production of ROS and mtDNA copies increased, HK1 expression increased, the expressions of SDHA, G6PD, RAD51 and ASCT-2 decreased, and the aerobic respiration decreased. CONCLUSIONS: Hypoxia plays an important role in maintaining mitochondrial functions in gastric cancer cells by promoting glycolysis and inhibiting mitochondrial aerobic respiration capacity.