HOP homeobox (HOPX) is an unusual homeobox gene encoding three spliced transcript variants, among which the only HOPX-b promoter harbors CpG islands. The characteristics of its promoter methylation was analyzed using bisulfite sequencing and quantitative-methylationspecific polymerase chain reaction (Q-MSP), and the effects of HOPX expression were also examined. HOPX-b expression was silenced in all gastric cancer cell lines tested; its expression could be restored by treatment with demethylating agent. On Q-MSP, HOPX-b hypermethylation (cut-off value of 3.55) was found in 84% (67 out of 80) of primary tumor tissues and 10% (8 out of 80) of the corresponding normal tissues and could discriminate normal from tumor tissues (Po0.0001). The prognosis of the advanced cases with HOPX-b hypermethylation was as poor as those with stage IV disease when cut-off value was set at 11.28. This finding was validated in an independent cohort of 90 advanced gastric cancers. The HOPX-b hypermethylation was also an independent prognostic factor (P ¼ 0.029) on multivariate analysis. Exogenous HOPX expression significantly inhibited cell proliferation, colony formation and invasion as well as enhanced apoptosis. Taken together, HOPX-b promoter methylation is a frequent and cancer-specific event in gastric cancer. Quantitative assessment of HOPX-b methylation has great clinical potential as a marker of tumor aggressiveness.

Homeodomain-only protein X (HOPX)-β promoter methylation was recently shown to be frequent in human cancers and was suggested as tumor suppressor gene in esophageal and gastric cancer. The aim of this study was to investigate the mechanistic roles of HOPX-β promoter methylation and its clinical relevance in colorectal cancer (CRC). HOPX-β promoter methylation was assessed in human CRC cell lines and 294 CRC tissues. HOPX mRNA and protein levels were measured in relation to HOPX-β promoter methylation. The effects of forced HOPX expression on tumorigenesis were studied using in vitro and in vivo assays. The association between HOPX-β promoter methylation and clinical relevance of CRC patients was determined. HOPX-β promoter methylation is cancer-specific and frequently found in CRC cell lines and tissues, resulting in the down-regulation of HOPX mRNA and protein levels. In CRC cell lines, forced expression of HOPX suppressed proliferation, invasion, and anchorage-independent growth. DNA microarray analyses suggested critical downstream genes that are associated with cancer cell proliferation, invasion or angiogenesis. In a mouse xenograft model, HOPX inhibited tumorigenesis and angiogenesis. Finally, HOPX-β promoter methylation was associated with worse prognosis of stage III CRC patients (hazard ratio= 1.40, P = .035) and also with poor differentiation (P = .014). In conclusion, HOPX-β promoter methylation is a frequent and cancer-specific event in CRC progression. This epigenetic alteration may have clinical ramifications in the diagnosis and treatment of CRC patients.

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Background: Improvements in the biocompatibility of dialysis membranes have reduced biological responses elicited by blood-membrane interactions. In this article, recent technological developments in dialysis membranes with regard to biocompatibility and recent progress in the evaluation of the biocompatibility of dialysis membranes are reviewed. Summary: The focus of investigation into dialysis membranes in recent years has focused on not only membrane materials, but also their surface textures, which have been changed, for example, by coating with vitamin E or by changing the amount and type of hydrophilizing agents used. Research and development is directed at altering the chemical and physical properties of membrane surfaces to suppress biological responses that are particularly elicited as a result of platelet activation. To develop membranes with excellent biocompatibility, biocompatibility should be evaluated on a like-for-like basis under conditions that are similar to those in clinical settings. Evaluation using actual dialyzers can be performed using porcine blood, platelet-rich plasma isolated from porcine blood (and platelet-rich plasma with leukocytes), or suspension of neutrophils isolated from porcine blood or cultured human monocytes. Key Messages: Highly biocompatible dialysis membranes can be developed when the overall correlations among biological reactions are examined by integrating all data on biological responses elicited by blood-membrane interactions or mutual interactions among blood cells.

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Inhaled nitric oxide (NO) has been reported to decrease the infarct size in cardiac ischemia-reperfusion (I/R) injury. However, reactive nitrogen species (RNS) produced by NO cause myocardial dysfunction and injury. Because H₂ is reported to eliminate peroxynitrite, it was expected to reduce the adverse effects of NO. In mice, left anterior descending coronary artery ligation for 60 min followed by reperfusion was performed with inhaled NO [80 parts per million (ppm)], H₂ (2%), or NO + H₂, starting 5 min before reperfusion for 35 min. After 24 h, left ventricular function, infarct size, and area at risk (AAR) were assessed. Oxidative stress associated with reactive oxygen species (ROS) was evaluated by staining for 8-hydroxy-2'-deoxyguanosine and 4-hydroxy-2-nonenal, that associated with RNS by staining for nitrotyrosine, and neutrophil infiltration by staining for granulocyte receptor-1. The infarct size/AAR decreased with breathing NO or H₂ alone. NO inhalation plus H₂ reduced the infarct size/AAR, with significant interaction between the two, reducing ROS and neutrophil infiltration, and improved the cardiac function to normal levels. Although nitrotyrosine staining was prominent after NO inhalation alone, it was eliminated after breathing a mixture of H₂ with NO. Preconditioning with NO significantly reduced the infarct size/AAR, but not preconditioning with H₂. In conclusion, breathing NO + H₂ during I/R reduced the infarct size and maintained cardiac function, and reduced the generation of myocardial nitrotyrosine associated with NO inhalation. Administration of NO + H₂ gases for inhalation may be useful for planned coronary interventions or for the treatment of I/R injury.

To clarify the internal fatigue crack generation in a Ti-Fe-O (near ␣-type) alloy, microstructures, internal fatigue crack initiation sites, and dislocation structures in samples fractured during high-cycle fatigue tests at liquid nitrogen temperature were studied. The alloy contained two kinds of elongated ␣-phase microstructures, i.e., recovered ␣ grains and recrystallized ␣ grains. Untested samples contained mobile dislocations in recovered ␣ grains, but in recrystallized ␣ grains, any dislocations were observed. Internal crack initiation sites were formed transgranularly and were related to the recrystallized ␣ grain region, judging from their morphology, size, and chemistry. Dislocations in recovered ␣ grains were rearranged after cyclic loading in either {0110} Ϫ ͗1120͘ planar arrays or subgrain structures due to dislocation annihilation. Few dislocations were seen in recrystallized ␣ grains. We discuss the relationship between localized strain incompatibility due to coplanar arrays in recovered ␣ grains and transgranular cracking in recrystallized ␣ grains, and propose a model for fatigue crack generation. H. YOKOYAMA, formerly Graduate Student, Department of Mechanical atomic size misfit, solute content, short-range order, and Engineering, Kogakuin University, is Engineer, Nittan Valve Co. Ltd., dispersion particles. [16,17] Thus, internal crack initiation must Kanagawa 257-0031, Japan. O. UMEZAWA, Senior Scientist, and K. be related to the size of the initiation site, [18] applied stress, [10] NAGAI, Unit Leader, are with the Frontier Research Center for Structural and microstructural factors [5,11,18,19] such as grain size, distri-Materials, National Research Institute for Metals, Ibaraki 305-0047, Japan. T. SUZUKI, Emeritus Professor, and K. KOKUBO, Professor, are with the bution, chemistry, and texture. In studies of internal crack Department of Mechanical Engineering, Kogakuin University, Tokyo 163initiation for a Ti-5Al-2.5Sn extra-low interstitials (ELI) 8677, Japan. alloy, [20] localized slip in a specific inhomogeneous micro