New anti-proliferative agent,MK615,from Japanese apricot “Prunus mume” induces striking autophagy in colon cancer cells in vitro

AIM: To investigate the anti-neoplastic effects of MK615, an extract from the Japanese apricot (Prunus mume), against colon cancer cells. METHODS: Three colon cancer cell lines, SW480, COLO, and WiDr, were cultured with MK615. Growth inhibition was evaluated by cell proliferation assay and killing activity was determined by lactate dehydrogenase assay. Induction of apoptosis was evaluated by annexin Ⅴ flow cytometry. Morphological changes were studied by light and electron microscopy, and immunofluorescence staining with Atg8. RESULTS: MK615 inhibited growth and lysed SW480, COLO and WiDr cells in a dose-dependent manner. Annexin Ⅴ flow cytometry showed that MK615 induced apoptosis after 6 h incubation, at which point the occurrence of apoptotic cells was 68.0%, 65.7% and 64.7% for SW480, COLO, and WiDr cells, respectively. Light and electron microscopy, and immunofluorescence staining with Atg8 revealed that MK615 induced massive cytoplasmic vacuoles (autophagosomes) in all three cell lines. CONCLUSION: MK615 has an anti-neoplastic effect against colon cancer cells. The effect may be exerted by induction of apoptosis and autophagy.

MK615 decreases RAGE expression and inhibits TAGE-induced proliferation in hepatocellular carcinoma cells

AIM:To investigate the proliferative effect of advanced glycation end-products(AGEs) and the role of their cellular receptor(RAGE) on hepatocellular carcinoma(HCC) cells,and the inhibitory effects of MK615,an extract from Japanese apricot,against AGEs were also evaluated.METHODS:Two HCC cell lines,HuH7 and HepG2,were used.Expression of RAGE was investigated by poly-merase chain reaction,Western blotting,and flow cytemetry(FACS).The effect of MK615 on RAGE expression was also evaluated by FACS.The proliferative effects of a control(unglycated bovine serum albumin),glucosederived AGEs(Glc-AGE),and glyceraldehyde-derived AGEs(Glycer-AGE),and the anti-proliferative effect of MK615 against AGEs,were evaluated using MTT assays.RESULTS:Expression of RAGE was confirmed at both the mRNA and protein levels in both HuH7 and HepG2.FACS revealed that the level of RAGE expression was higher in HuH7 than in HepG2.Treatment with 0.1 μg/mL MK615 decreased the expression level of RAGE from 24.3% to 3.7% in HuH7 and from 6.2% to 4.8% in HepG2.The growth indices for the control,Glc-AGE,and Glycer-AGE were 1.06 ± 0.08,0.99 ± 0.04,and 1.38 ± 0.05,respectively,in HuH7(P = 0.037),and were 1.03 ± 0.04,1.04 ± 0.03,and 1.07 ± 0.05,respectively,in HepG2(P > 0.05).When the cells were cultured simultaneously with Glycer-AGE and MK615,MK615 abrogated the proliferative effect of Glycer-AGE in HuH7.CONCLUSION:Only Glycer-AGE has a proliferative effect on HuH7,which expresses a higher level of RAGE.MK615 suppresses the proliferative effect of GlycerAGE on HuH7 by decreasing the expression of RAGE.

MK615 inhibits pancreatic cancer cell growth by dual inhibition of Aurora A and B kinases

AIM:To investigate the anti-neoplastic effect of MK615, an anti-neoplastic compound isolated from Japanese apricot, against human pancreatic cancer cells in vitro. METHODS: Three human pancreatic cancer cell lines PANC-1, PK-1, and PK45H were cultured with MK615 at concentrations of 600, 300, 150, and 0 μg/mL. Growth inhibition was evaluated by cell proliferation assay, and killing activity was determined by lactate dehydrogenase (LDH) assay. Expression of Aurora A and B kinases was detected by real-time polymerase chain reaction (PCR) and Western blotting. Cell cycle stages were evaluated by flow cytometry. RESULTS: The growth inhibitory rates of MK615 at 150, 300, and 600 μg/mL were 2.3% ± 0.9%, 8.9% ± 3.2% and 67.1% ± 8.1% on PANC1 cells, 1.3% ± 0.3%, 8.7% ± 4.1% and 45.7 ± 7.6% on PK1 cells, and 1.2 ± 0.8%, 9.1% ± 2.1% and 52.1% ± 5.5% on PK45H cells, respectively (P <0.05). The percentage cytotoxicities of MK615 at 0, 150, 300, and 600 μg/mL were 19.6% ± 1.3%, 26.7% ± 1.8%, 25.5% ± 0.9% and 26.4% ± 0.9% in PANC1 cells, 19.7% ± 1.3%, 24.7% ± 0.8%, 25.9% ± 0.9% and 29.9% ± 1.1% in PK1 cells, and 28.0% ± 0.9%, 31.2% ± 0.9%, 30.4% ± 1.1% and 35.3 ± 1.0% in PK45H cells, respectively (P < 0.05). Real-time PCR and Western blotting showed that MK615 dually inhibited the expression of Aurora A and B kinases. Cell cycle analysis revealed that MK615 increased the population of cells in G2/M phase. CONCLUSION: MK615 exerts an anti-neoplastic effect on human pancreatic cancer cells in vitro by dual inhibition of Aurora A and B kinases.

900～2800K多晶石墨电阻率与温度的关系

1.前言石墨,在惰性气氛下有3300K以上的耐热性,加之它在导电、耐粒子等方面也显示优异的特性,因此作为超高温炉的发热体、宇航材料、原子反应堆用材料等被广泛利用。然而,测定1800K以上的物性,在设备和技术方面是困难的。目前超高温用石墨材料的设计是采用从低温区域得到的石墨数据外推值,再参考经验积累的推断值进行的。因此,开发能够高精度测量炭,石墨材料的电气、机械、高温特性的设备,进而确立可靠性高的评价技术就显得很迫切。有关3300K温度范围内的电导率,虽然美国,苏联已有报告发表,但测试设备和测试条件没有详细说明,并且测试的试样也只局限于特定的石墨种类。