As climate is not only a valuable tourism resource but also a factor influencing travel experience, estimating climate change can provide implications to sustainable development of the tourism industry. This study develops Climate Volatility Index (CVI) using GARCH model and estimates the relationship between CVI and Japanese tourism demand for Korea using a tourism demand model, based on data from January 2000 to December 2013. Time lag is applied based on a decision making process regarding travel destinations. The result shows that an increase in volatility of climate change leads to a decrease in tourism demand.

Ovarian cancer is the common cause of death among gynecological cancers. Although ovarian cancer initially responds to chemotherapy, the frequent recurrence in patients remains a therapeutic challenge. Pyruvate kinase M2 (PKM2) plays a pivotal role in regulating cancer cell survival. However, its therapeutic roles remain unclear. Here, we investigated the anticancer effects of compound 3K, a specific PKM2 inhibitor, on autophagic and apoptotic pathway regulation in SK-OV-3 (PKM2-overexpressing human ovarian adenocarcinoma cell line). The anticancer effect of compound 3K was examined using the MTT and colony formation assay in SK-OV-3. The results of tissue microarray showed that PKM2 expression positively correlated with the severity of the tumor. Moreover, the expression of pro-apoptotic proteins increased in SK-OV-3 following compound 3K treatment. Compound 3K induced AMPK activation, which was accompanied by the inhibition of mTOR. Additionally, this compound inhibited glycolysis, resulting in reduced proliferation in SK-OV-3. Compound 3K treatment suppressed tumor progression in vivo xenograft model. Our findings suggest that the inhibition of PKM2 by compound 3K affected Warburg effects and induced autophagic cell death. Therefore, the use of specific PKM2 inhibitors to block the glycolytic pathway and target cancer cell metabolism represents a promising therapeutic approach for treating PKM2-overexpressing ovarian cancer.

We previously found a novel a new sirtuin (SIRT) inhibitor MHY2256 that exerts anticancer activity through p53 acetylation in MCF-7 human breast cancer cells. Here, we investigated the anticancer activity of MHY2256 against hormone-related cancer, which is an endometrial cancer with poor prognosis. We found that MHY2256 markedly reduced cellular proliferation at low concentrations against Ishikawa endometrial cancer cells. The IC50 values of MHY2256 were much lower than that of salermide. Furthermore, MHY2256 significantly reduced the protein expression and activities of SIRT1, 2, and 3 with similar effects as salermide, a well-known SIRT inhibitor. Particularly, MHY2256 markedly inhibited tumor growth in a tumor xenograft mouse model of Ishikawa cancer cells. During the experimental period, there was no significant change in the body weight of mice treated with MHY2256. Detailed analysis of the sensitization mechanisms of Ishikawa cells revealed that late apoptosis was largely increased by MHY2256. Additionally, MHY2256 increased G1 arrest and reduced cell cyclic-related proteins, suggesting that apoptosis by MHY2256 was achieved by cellular arrest. Particularly, p21 was greatly increased by MHY225656, suggesting that cell cycle arrest by p21 is a major factor in MHY2256 sensitization in Ishikawa cells. We also detected a significant increase in acetylated p53, a target protein of SIRT1, in Ishikawa cells after MHY2256 treatment. In a mouse xenograft model, MHY2256 significantly reduced tumor growth and weight without apparent side effects. These results suggest that MHY2256 exerts its anticancer activity through p53 acetylation in endometrial cancer and can be used for targeting hormone-related cancers.

Pyruvate kinase M2 (PKM2) is essential for aerobic glycolysis and is highly expressed in various cancer tissues. Although high PKM2 expression is observed in prostate cancer tissues, its functional role in cancer metabolism is unclear. Here, we investigated the role of PKM2 in regulating autophagy and its associated pathways in prostate cancer cells. PKM2 expression was silenced using various PKM2 small interfering RNAs (siRNAs) and then we measured PKM2-related cellular pathways associated with autophagy. PKM2 siRNA-transfected prostate cancer cells showed significantly reduced viability. Acridine orange staining and immunoblotting analysis showed that PKM2 downregulation markedly increased autophagic cell death. Results of western blotting analysis showed that PKM2 knockdown affected protein kinase B/mechanistic target of rapamycin 1 pathway, which consequently downregulated the expression of glycolytic enzymes lactate dehydrogenase A and glucose transporter 1. To the best of our knowledge, this is the first study to show that PKM2 inhibition alters cancer cell metabolism and induces autophagy. Thus, the present study provides a strategy for the development of PKM2-targeted novel anticancer drugs for the treatment of prostate cancer.

Osteoporosis, often linked to increased osteoclast activity due to menopause or aging, was the focus. In this study, the inhibitory effects of Salicornia europaea L. (SE) water extract of desalted SE (WSE) were investigated on osteoclast differentiation and bone loss in ovariectomized mice. The findings revealed that WSE effectively inhibited RANKL-induced osteoclast differentiation, as evidenced by TRAP staining, and also suppressed bone resorption and F-actin ring formation in a dose-dependent manner. Gene expressions related to osteoclast differentiation, including NFATc1, TRAP, cathepsin K, and DC-STAMP, were downregulated by WSE. Oral administration of WSE improved bone density and structural parameters in ovariectomized mice. Dicaffeoyl quinic acids (DCQAs) and saponins in WSE were detected, with 3,4-, 3,5-, and 4,5-DCQA isolated and identified. All tested DCQAs, including the aforementioned types, inhibited osteoclast differentiation, bone resorption, and the expression of osteoclast-related genes. Furthermore, WSE and DCQAs reduced ROS production mediated by RANKL. These results indicate the potential of WSE and its components, DCQA, as preventive or therapeutic agents against osteoporosis and related conditions.