Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal types of cancer and the 5-year survival rate is only 5%. Several studies have suggested that cancer stem cells (CSCs) are thought to be involved in recurrence and metastasis and so it is essential to establish an approach targeting CSCs. Here we have demonstrated that cyclic guanosine monophosphate (cGMP) suppressed CD44 expression and the properties of CSCs in PDAC. Microarray analysis suggested that cGMP inhibited Forkhead box O3 (FOXO3), which is known as a tumor suppressor. Surprisingly, our data demonstrated that FOXO3 is essential for CD44 expression and the properties of CSCs. Our data also indicated that patients with high FOXO3 activation signatures had poor prognoses. This evidence suggested that cGMP induction and FOXO3 inhibition could be ideal candidates for pancreatic CSC.

An epidemiological study showed that green tea consumption is associated with a reduced risk of hematopoietic malignancy. The major green tea polyphenol epigallocatechin-3-O-gallate (EGCG) is reported to have anticancer effects. Chronic myeloid leukemia (CML) is a major hematopoietic malignancy characterized by expansion of myeloid cells. In the present study, we showed EGCG-induced acid sphingomyelinase (ASM) activation and lipid raft clustering in CML cells. The ASM inhibitor desipramine significantly reduced EGCG-induced cell death. Protein kinase Cδ is a well-known kinase that plays an important role in ASM activation. We observed EGCG-induced phos-phorylation of protein kinase Cδ at Ser664. Importantly, EGCG-induced ASM activation was significantly reduced by pretreatment of CML cells with the soluble guanylate cyclase inhibitor NS2028, suggesting that EGCG induced ASM activation through the cyclic guanosine monophosphate (cGMP)-dependent pathway. Indeed, pharmacological inhibition of a cGMP-negative regulator enhanced the anti-CML effect of EGCG. These results indicate that EGCG-induced cell death via the cGMP/ASM pathway in CML cells.

Nowadays, new types of vinegar have been developed using various raw materials and biotechnological processes. The fruit of Prunus mume has been extensively distributed in East Asia and used as a folk medication for fatigue. In this study, the Prunus mume vinegar (PV) was produced by a two-step fermentation and was evaluated for its anti-fatigue activity by C2C12 myoblasts and high-intensity exercised rats. The administration of PV significantly improved running endurance and glycogen accumulation in the liver and muscle of PV supplemented rats compared to sedentary and exercised control groups. In addition, PV supplementation elicited lower fatigue-related serum biomarkers, for instance, ammonia, inorganic phosphate, and lactate. PV administered rats exhibited higher lactate dehydrogenase activity and glutathione peroxidase activity, and lower creatine kinase activity and malondialdehyde levels. Furthermore, phenolic compounds in PV were identified using HPLC analysis. The phenolic acids analyzed in PV were protocatechuic acid, syringic acid, chlorogenic acid, and its derivates. These results indicate that the administration of PV with antioxidative property contributes to the improvement of fatigue recovery in exhausted rats. The findings of this study suggest that the PV containing various bioactive constituents can be used as a functional material against fatigue caused by high-intensity exercise.

Pectinase is a well‐known enzyme used in the food processing industry to produce fruit juice and concentrate. This study evaluated the anticancer and antiangiogenesis activities of pectinase‐treated Prunus mume fruit concentrate (PC) and its phenolic components. PC treatment (250 to 1,000 µg/mL) resulted in decreased proliferation of SW480 human colorectal cancer cells through S‐phase cell cycle arrest; however, equivalent concentrations of PC did not show toxicity toward CRL‐1539 colon normal cells. Furthermore, PC‐induced caspase‐dependent apoptosis in SW480 cells, which was characterized by accumulation of apoptotic cell population, cell shrinkage, formation of apoptotic bodies, upregulation of proapoptotic Bax, cleaved PARP, caspase‐3, caspase‐8, and caspase‐9, and downregulation of antiapoptotic Bcl‐2. Antiangiogenesis effects of PC were assessed using human umbilical vein endothelial cells (HUVECs). We found that PC did not inhibit HUVECs proliferation at concentrations of 500 to 1,500 µg/mL. In addition, treatment with PC at nontoxic concentrations (500 to 1,000 µg/mL) blocked vascular endothelial growth factor induced cell migration, invasion, capillary‐like tube formation, and angiogenesis from rat aortic rings. HPLC‐PDA analysis showed that there were at least four different phenolics including 5‐HMF, neochlorogenic acid, protocatechuic acid, and syringic acid. Taken together, these results indicated that PC could be used as a good source of phenolic compounds with selective anticancer and antiangiogenesis activities. Practical Application Pectinases are one of the well‐known enzyme used in the part of food processing. Treatment of pectinase is a useful strategy to reduce viscosity, turbidity, and pulp particles in the production of fruit juice, extract, and concentrate. In the present study, we found that pectinase‐treated P. mume fruit concentrate significantly suppresses colorectal cancer proliferation and angiogenesis of human umbilical vein endothelial cells. The significance of our findings is that pectinase‐treated P. mume concentrate may be used as a commercial functional food material to inhibit colorectal cancer and angiogenesis.

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