esculetin and Stomach-Neoplasms

Aesculetin is an active member of coumarins that has been reported to possess significant medicinal and biological importance. It has also been shown with potential anticancer activity against different human cancers including breast, lung and hepatocellular carcinoma. Therefore, the current investigation was undertaken to examine the anticancer effects of aesculetin against gastric cancer. MTT assay was performed to check the cellular viability and clonogenic assay was executed to assess the effect of aesculetin on colony formation capacity of SGC-7901 gastric cancer cells. Apoptosis was analysed by AO/EB staining and annexin V-FITC/PI staining assays. Cell cycle phases were monitored using flowcytometry and western blotting was used to detect the effects of aesculetin on PI3K/AKT/M-TOR signalling pathway. Results indicated that aesculetin not only reduced the cellular proliferation in time-dependent manner but dose-dependent manner as well. Clonogenic tendency of SGC-7901 cells was retarded significantly by the aesculetin. The antiproliferative effects of aesculetin may arbitrate via apoptosis. Further, flow cytometric analysis revealed that the G2/M-phase SGC-7901 cells amplified number with increasing aesculetin doses. Indicating blocking of cell cycle at G2/M-phase. Finally, western blotting assay suggested blocking of PI3K/AKT/M-TOR signalling pathway by aesculetin in gastric cancer SGC-7901 cells. Taking altogether, aesculetin could induce significant growth inhibitory effects against gastric cancer SGC-7901 cells. Moreover, aesculetin could induce apoptotic cell death, cell cycle arrest and block PI3K/AKT/M-TOR signalling pathway.

Topics: Antineoplastic Agents; Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Humans; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction; Stomach Neoplasms; TOR Serine-Threonine Kinases; Umbelliferones

In this study, we aimed to investigate the antitumor effect of esculetin, a coumarin derivative extracted from natural plants, on human gastric cancer cells, and to illustrate the potential mechanisms. The results showed that esculetin exhibited anti-proliferative effects against gastric cancer cells and induced their apoptosis in a dose dependent manner with lower toxicity against normal gastric epithelial cells. Mechanism study indicated that esculetin induced gastric cancer MGC-803 cells apoptosis by triggering the activation of mitochondrial apoptotic pathway through reducing the mitochondrial membrane potential (MMP), increasing Bax/Bcl-2 ratio, activating caspase-3 and caspase-9 activity, and increasing cytochrome c release from mitochondria. Further study showed that the pro-apoptotic effects of esculetin were associated with down-regulation of insulin-like growth factor-1/ phosphatidylinositide 3-kinase/protein kinase B (IGF-1/PI3K/Akt) signaling pathway. Activation of IGF-1/PI3K/Akt pathway by IGF-1 abrogated the pro-apoptotic effects of esculetin, while inhibition of IGF-1/PI3K/Akt pathway by triciribine or LY294002 enhanced the pro-apoptotic effects of esculetin. In addition, esculetin inhibited in vivo tumor growth with no obvious toxicity following subcutaneous inoculation of MGC-803 cells in nude mice, and inhibited activation of IGF-1/PI3K/Akt pathway in tumor tissue.. These results indicate that esculetin could inhibit cell proliferation and induce apoptosis of gastric cancer cells through IGF-1/PI3K/Akt mediated mitochondrial apoptosis pathway, and may be a novel effective chemotherapeutic agent against gastric cancer.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Female; Humans; Insulin-Like Growth Factor I; Mice; Mice, Nude; Mitochondria; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction; Stomach Neoplasms; Umbelliferones; Xenograft Model Antitumor Assays

Esculetin is a coumarin derivative from natural plants that has been commonly used as a folk medicine and has been reported to have beneficial pharmacological and biochemical activities; however, the mechanism by which esculetin prevents human gastric cancer cell growth is still largely unknown. In this study, we investigated the effect of esculetin on human gastric cancer cells and explored the cell death mechanism. Our data indicated that esculetin inhibited the growth of human gastric cancer cells in a dose- and time-dependent manner and apoptosis was the main cause of decreased cell viability in esculetin-treated cells. Additionally, esculetin treatment increased the activity of caspase-9 and caspase-3, and resulted in the appearance of the PARP cleavage product; and esculetin-induced cell death and apoptosis was decreased by pretreatment with CsA and NAC, but not BA; these results demonstrate that esculetin induced apoptosis via the caspase-dependent mitochondrial pathway in human gastric cancer cells in which cyclophilin D mediated the cytotoxic action by triggering the opening of the mitochondrial permeability transition pore; and the generation of ROS not only was a consequence of mitochondrial dysfunction, but also triggered esculetin-induced apoptosis. These results reveal a novel mechanism of esculetin on gastric cancer cells and suggest that esculetin could be a novel agent in the treatment of gastric cancer.

Topics: Apoptosis; Caspases; Cell Line, Tumor; Cyclophilins; Humans; Mitochondria; Peptidyl-Prolyl Isomerase F; Permeability; Reactive Oxygen Species; Stomach Neoplasms; Umbelliferones