Downregulation of SMOC1 is associated with progression of colorectal traditional serrated adenomas

BACKGROUND

Aberrant DNA methylation is prevalent in colorectal serrated lesions. We previously reported that the CpG island of SMOC1 is frequently methylated in traditional serrated adenomas (TSAs) and colorectal cancers (CRCs) but is rarely methylated in sessile serrated lesions (SSLs). In the present study, we aimed to further characterize the expression of SMOC1 in early colorectal lesions.

METHODS

SMOC1 expression was analyzed immunohistochemically in a series of colorectal tumors (n = 199) and adjacent normal colonic tissues (n = 112).

RESULTS

SMOC1 was abundantly expressed in normal colon and SSLs while it was significantly downregulated in TSAs, advanced adenomas and cancers. Mean immunohistochemistry scores were as follows: normal colon, 24.2; hyperplastic polyp (HP), 18.9; SSL, 23.8; SSL with dysplasia (SSLD)/SSL with early invasive cancer (EIC), 15.8; TSA, 5.4; TSA with high grade dysplasia (HGD)/EIC, 4.7; non-advanced adenoma, 21.4; advanced adenoma, 11.9; EIC, 10.9. Higher levels SMOC1 expression correlated positively with proximal colon locations and flat tumoral morphology, reflecting its abundant expression in SSLs. Among TSAs that contained both flat and protruding components, levels of SMOC1 expression were significantly lower in the protruding components.

CONCLUSION

Our results suggest that reduced expression of SMOC1 is associated with progression of TSAs and conventional adenomas and that SMOC1 expression may be a biomarker for diagnosis of serrated lesions and risk prediction in colorectal tumors.

ACLP Activates Cancer-Associated Fibroblasts and Inhibits CD8+ T-Cell Infiltration in Oral Squamous Cell Carcinoma

We previously showed that upregulation of adipocyte enhancer-binding protein 1 (AEBP1) in vascular endothelial cells promotes tumor angiogenesis. In the present study, we aimed to clarify the role of stromal AEBP1/ACLP expression in oral squamous cell carcinoma (OSCC). Immunohistochemical analysis showed that ACLP is abundantly expressed in cancer-associated fibroblasts (CAFs) in primary OSCC tissues and that upregulated expression of ACLP is associated with disease progression. Analysis using CAFs obtained from surgically resected OSCCs showed that the expression of AEBP1/ACLP in CAFs is upregulated by co-culture with OSCC cells or treatment with TGF-β1, suggesting cancer-cell-derived TGF-β1 induces AEBP1/ACLP in CAFs. Collagen gel contraction assays showed that ACLP contributes to the activation of CAFs. In addition, CAF-derived ACLP promotes migration, invasion, and in vivo tumor formation by OSCC cells. Notably, tumor stromal ACLP expression correlated positively with collagen expression and correlated inversely with CD8+ T cell infiltration into primary OSCC tumors. Boyden chamber assays suggested that ACLP in CAFs may attenuate CD8+ T cell migration. Our results suggest that stromal ACLP contributes to the development of OSCCs, and that ACLP is a potential therapeutic target.

TM4SF1-AS1 inhibits apoptosis by promoting stress granule formation in cancer cells

Long noncoding RNAs (lncRNAs) play pivotal roles in tumor development. To identify dysregulated lncRNAs in gastric cancer (GC), we analyzed genome-wide trimethylation of histone H3 lysine 4 (H3K4me3) to screen for transcriptionally active lncRNA genes in the non-tumorous gastric mucosa of patients with GC and healthy individuals. We found that H3K4me3 at TM4SF1-AS1 was specifically upregulated in GC patients and that the expression of TM4SF1-AS1 was significantly elevated in primary and cultured GC cells. TM4SF1-AS1 contributes to GC cell growth in vitro and in vivo, and its oncogenic function is mediated, at least in part, through interactions with purine-rich element-binding protein α (Pur-α) and Y-box binding protein 1 (YB-1). TM4SF1-AS1 also activates interferon signaling in GC cells, which is dependent on Pur-α and RIG-I. Chromatin isolation by RNA purification (ChIRP)-mass spectrometry demonstrated that TM4SF1-AS1 was associated with several stress granule (SG)-related proteins, including G3BP2, RACK1, and DDX3. Notably, TM4SF1-AS1 promoted SG formation and inhibited apoptosis in GC cells by sequestering RACK1, an activator of the stress-responsive MAPK pathway, within SGs. TM4SF1-AS1-induced SG formation and apoptosis inhibition are dependent on Pur-α and YB-1. These findings suggested that TM4SF1-AS1 contributes to tumorigenesis by enhancing SG-mediated stress adaptation.

CXCL12 is expressed by skeletal muscle cells in tongue oral squamous cell carcinoma

BACKGROUND

The CXCL12/CXCR4 axis plays a pivotal role in the progression of various malignancies, including oral squamous cell carcinoma (OSCC). In this study, we aimed to clarify the biological and clinical significance of CXCL12 in the tumor microenvironment of OSCCs.

METHODS

Publicly available single-cell RNA-sequencing (RNA-seq) datasets were used to analyze CXCL12 expression in head and neck squamous cell carcinomas (HNSCC). Immunohistochemical analysis of CXCL12, α-smooth muscle antigen (α-SMA), fibroblast activation protein (FAP) and CD8 was performed in a series of 47 surgically resected primary tongue OSCCs. Human skeletal muscle cells were co-cultured with or without OSCC cells, after which CXCL12 expression was analyzed using quantitative reverse-transcription PCR.

RESULTS

Analysis of the RNA-seq data suggested CXCL12 is abundantly expressed in stromal cells within HNSCC tissue. Immunohistochemical analysis showed that in grade 1 primary OSCCs, CXCL12 is expressed in both tumor cells and muscle cells. By contrast, grade 3 tumors were characterized by disruption of muscle structure and reduced CXCL12 expression. Quantitative analysis of CXCL12-positive areas within tumors revealed that reduced CXCL12 expression correlated with poorer overall survival. Levels of CXCL12 expression tended to inversely correlate α-SMA expression and positively correlate with infiltration by CD8+ lymphocytes, though these relations did not reach statistical significance. CXCL12 was significantly upregulated in muscle cells co-cultured with OSCC cells.

CONCLUSION

Our results suggest that tongue OSCC cells activate CXCL12 expression in muscle cells, which may contribute to tumor progression. However, CXCL12 is reduced in advanced OSCCs due to muscle tissue destruction.

Serum amyloid A1 recruits neutrophils to the invasive front of T1 colorectal cancers

BACKGROUND AND AIM

The tumor microenvironment plays an essential role in the development and progression of colorectal cancer (CRC). We recently reported that crosstalk between CRC cells and tumor-associated macrophages (TAMs) via serum amyloid A1 (SAA1) promotes invasion by T1 CRCs. In the present study, we aimed to clarify the role of neutrophils in early CRCs.

METHODS

Immunohistochemical analysis of CD66b, chemokine CXC motif ligand 8 (CXCL8 or interleukin-8, IL-8) and matrix metalloproteinase-9 (MMP-9) was performed using primary T1 CRCs (n = 49). The HL-60 human promyelocytic leukemia cell line and THP-1 human monocytic leukemia cell line were used to obtain neutrophil-like and macrophage-like cells, respectively. Boyden chamber assays were used to analyze cell migration and invasion, and quantitative RT-PCR was used to analyze gene expression.

RESULTS

Immunohistochemical analysis revealed accumulation of neutrophils at the SAA1-positive invasive front of T1 CRCs. Experiments using HL-60 cells suggested that treatment with SAA1 induced neutrophil migration and expression of CXCL8 and MMP-9 in neutrophils and that neutrophils promote CRC cell migration and invasion. Immunohistochemistry confirmed accumulation of CXCL8- or MMP-9-positive neutrophils at the SAA1-positive invasive front of T1 CRCs. Moreover, co-culture experiments using CRC, THP-1 and HL-60 cells suggested that CRC cells activated by macrophages upregulate CXCL8 and MMP-9 in neutrophils.

CONCLUSIONS

Our results suggest that interplay between macrophages and CRC cells leads to recruitment of neutrophils to the invasive front of T1 CRCs and that SAA1 secreted by CRC cells activate neutrophils to promote invasion.

DLEU1 promotes oral squamous cell carcinoma progression by activating interferon-stimulated genes

Long noncoding RNAs (lncRNAs) are deeply involved in cancer development. We previously reported that DLEU1 (deleted in lymphocytic leukemia 1) is one of the lncRNAs overexpressed in oral squamous cell carcinoma (OSCC) cells, where it exhibits oncogenic activity. In the present study, we further clarified the molecular function of DLEU1 in the pathogenesis of OSCC. Chromatin immunoprecipitation-sequencing (ChIP-seq) analysis revealed that DLEU1 knockdown induced significant changes in the levels of histone H3 lysine 4 trimethylation (H3K4me3) and H3K27 acetylation (H3K27ac) in OSCC cells. Notably, DLEU1 knockdown suppressed levels of H3K4me3/ H3K27ac and expression of a number of interferon-stimulated genes (ISGs), including IFIT1, IFI6 and OAS1, while ectopic DLEU1 expression activated these genes. Western blot analysis and reporter assays suggested that DLEU1 upregulates ISGs through activation of JAK-STAT signaling in OSCC cells. Moreover, IFITM1, one of the ISGs induced by DLUE1, was frequently overexpressed in primary OSCC tumors, and its knockdown inhibited OSCC cell proliferation, migration and invasion. These findings suggest that DLEU1 exerts its oncogenic effects, at least in part, through activation of a series ISGs in OSCC cells.

Activated macrophages promote invasion by early colorectal cancer via an interleukin 1β-serum amyloid A1 axis

Submucosal invasion and lymph node metastasis are important issues affecting treatment options for early colorectal cancer (CRC). In this study, we aimed to unravel the molecular mechanism underlying the invasiveness of early CRCs. We performed RNA‐sequencing (RNA‐seq) with poorly differentiated components (PORs) and their normal counterparts isolated from T1 CRC tissues and detected significant upregulation of serum amyloid A1 (SAA1) in PORs. Immunohistochemical analysis revealed that SAA1 was specifically expressed in PORs at the invasive front of T1b CRCs. Upregulation of SAA1 in CRC cells promoted cell migration and invasion. Coculture experiments using CRC cell lines and THP‐1 cells suggested that interleukin 1β (IL‐1β) produced by macrophages induces SAA1 expression in CRC cells. Induction of SAA1 and promotion of CRC cell migration and invasion by macrophages were inhibited by blocking IL‐1β. These findings were supported by immunohistochemical analysis of primary T1 CRCs showing accumulation of M1‐like/M2‐like macrophages at SAA1‐positive invasive front regions. Moreover, SAA1 produced by CRC cells stimulated upregulation of matrix metalloproteinase‐9 in macrophages. Our data suggest that tumor‐associated macrophages at the invasive front of early CRCs promote cancer cell migration and invasion through induction of SAA1 and that SAA1 may be a predictive biomarker and a useful therapeutic target.

An Integrated Epigenome and Transcriptome Analysis to Clarify the Effect of Epigenetic Inhibitors on GIST

BACKGROUND/AIM

Epigenetic alterations play an important role in the pathogenesis of gastrointestinal stromal tumors (GISTs). To obtain further insight into the GIST epigenome, we analyzed genome-wide histone modification and DNA methylation in GIST cells.

MATERIALS AND METHODS

To reverse epigenetic silencing, GIST-T1 cells were treated with a DNA methyltransferase inhibitor and a histone deacetylase inhibitor, and subsequently H3K4me3 levels, the DNA methylome, and the transcriptome were analyzed.

RESULTS

Treatment with epigenetic inhibitors not only up-regulated genes with DNA methylation, but also genes related to interferon signaling. ChIP-seq analysis revealed that drug treatment up-regulated H3K4me3 levels in retrotransposons, including endogenous retroviruses (ERV). Finally, utilizing the omics data, we found that hypermethylation of MEG3 is a frequent event and an indicator of poorer prognosis in GIST patients.

CONCLUSION

Epigenetic inhibitors may activate interferon signaling via viral mimicry in GIST cells. Moreover, epigenome data could be a useful resource to identify novel GIST-related genes.

Regulatory roles of claudin-1 in cell adhesion and microvilli formation

Aberrant expression of tight junction proteins has recently been focused on in the cancer research field. We previously showed that claudin-1 is aberrantly expressed from an early stage of uterine cervical adenocarcinoma and contributes to malignant potentials. To elucidate the molecular mechanisms underlying tumor-promoting roles of claudin-1, we established and analyzed claudin-1 knockout cells. Knockout of claudin-1 suppressed conventional tight junctional functions, barrier and fence functions, and expression of cell adhesion-associated proteins including E-cadherin. Comparative proteome analysis revealed that expression of claudin-1 affected expression of a wide range of proteins, especially proteins that are associated with cell adhesion and actin cytoskeleton remodeling. Interactome analysis of the identified proteins revealed that E-cadherin and focal adhesion kinase play central roles in the claudin-1-dependently affected protein network. Moreover, knockout of claudin-1 significantly suppressed microvilli formation and activity of Ezrin/Radixin/Moesin. Taken together, the results indicate that expression of claudin-1 affects not only conventional tight junction function but also expression and activity of a wide range of proteins, especially proteins that are associated with cell adhesion and actin cytoskeleton remodeling, to contribute to malignant potentials and microvilli formation in cervical adenocarcinoma cells.

Metabolomic profiling of urine-derived extracellular vesicles from rat model of drug-induced acute kidney injury

Extracellular vesicles (EVs) are lipid bilayer particles that are released by various cells and provide a real-time snapshot of the state of these cells in tissue in a noninvasive manner. EVs contain components, including mRNA, miRNAs, proteins, and metabolites. Therefore, EVs hold promise for the discovery of liquid biopsy-based biomarkers for disease diagnosis. In the present study, metabolome analysis of urine EVs in rats with kidney injury caused by cisplatin and puromycin aminonucleoside was performed using liquid chromatography/mass spectrometry to identify candidate biomarkers that reflect the type and extent of injury in drug-induced nephrotoxicity. A total of 396 metabolites were detected in urine EVs, of which 65 were identified as potential biomarkers in urine EVs of drug-induced nephrotoxicity. Pathway analysis revealed that these metabolites may reflect changes occurring within damaged cells during kidney injury, suggesting that metabolomics of urine EVs could be a useful informative tool.

Transfer of orbital angular momentum of light to plasmonic excitations in metamaterials

The emergence of the vortex beam with orbital angular momentum (OAM) has provided intriguing possibilities to induce optical transitions beyond the framework of the electric dipole interaction. The uniqueness stems from the OAM transfer from light to material, as demonstrated in electronic transitions in atomic systems. In this study, we report on the OAM transfer to electrons in solid-state systems, which has been elusive to date. Using metamaterials (periodically textured metallic disks), we show that multipolar modes of the surface electromagnetic excitations (so-called spoof localized surface plasmons) are selectively induced by the terahertz vortex beam. Our results reveal selection rules governed by the conservation of the total angular momentum, which is confirmed by numerical simulations. The efficient transfer of light's OAM to elementary excitations in solid-state systems at room temperature opens up new possibilities of OAM manipulation.

Upregulation of adipocyte enhancer-binding protein 1 in endothelial cells promotes tumor angiogenesis in colorectal cancer

Tumor angiogenesis is an important therapeutic target in colorectal cancer (CRC). We aimed to identify novel genes associated with angiogenesis in CRC. Using RNA sequencing analysis in normal and tumor endothelial cells (TECs) isolated from primary CRC tissues, we detected frequent upregulation of adipocyte enhancer‐binding protein 1 (AEBP1) in TECs. Immunohistochemical analysis revealed that AEBP1 is upregulated in TECs and stromal cells in CRC tissues. Quantitative RT‐PCR analysis showed that there is little or no AEBP1 expression in CRC cell lines, but that AEBP1 is well expressed in vascular endothelial cells. Levels of AEBP1 expression in Human umbilical vein endothelial cells (HUVECs) were upregulated by tumor conditioned medium derived from CRC cells or by direct coculture with CRC cells. Knockdown of AEBP1 suppressed proliferation, migration, and in vitro tube formation by HUVECs. In xenograft experiments, AEBP1 knockdown suppressed tumorigenesis and microvessel formation. Depletion of AEBP1 in HUVECs downregulated a series of genes associated with angiogenesis or endothelial function, including aquaporin 1 (AQP1) and periostin (POSTN), suggesting that AEBP1 might promote angiogenesis through regulation of those genes. These results suggest that upregulation of AEBP1 contributes to tumor angiogenesis in CRC, which makes AEBP1 a potentially useful therapeutic target.

UHRF1 depletion and HDAC inhibition reactivate epigenetically silenced genes in colorectal cancer cells

BACKGROUND

Ubiquitin-like protein containing PHD and RING finger domains 1 (UHRF1) is a major regulator of epigenetic mechanisms and is overexpressed in various human malignancies. In this study, we examined the involvement of UHRF1 in aberrant DNA methylation and gene silencing in colorectal cancer (CRC).

RESULTS

CRC cell lines were transiently transfected with siRNAs targeting UHRF1, after which DNA methylation was analyzed using dot blots, bisulfite pyrosequencing, and Infinium HumanMethylation450 BeadChip assays. Gene expression was analyzed using RT-PCR and gene expression microarrays. Depletion of UHRF1 rapidly induced genome-wide DNA demethylation in CRC cells. Infinium BeadChip assays and bisulfite pyrosequencing revealed significant demethylation across entire genomic regions, including CpG islands, gene bodies, intergenic regions, and repetitive elements. Despite the substantial demethylation, however, UHRF1 depletion only minimally reversed CpG island hypermethylation-associated gene silencing. By contrast, the combination of UHRF1 depletion and histone deacetylase (HDAC) inhibition reactivated the silenced genes and strongly suppressed CRC cell proliferation. The combination of UHRF1 depletion and HDAC inhibition also induced marked changes in the gene expression profiles such that cell cycle-related genes were strikingly downregulated.

CONCLUSIONS

Our results suggest that (i) maintenance of DNA methylation in CRC cells is highly dependent on UHRF1; (ii) UHRF1 depletion rapidly induces DNA demethylation, though it is insufficient to fully reactivate the silenced genes; and (iii) dual targeting of UHRF1 and HDAC may be an effective new therapeutic strategy.

Surface microstructures are associated with mutational intratumoral heterogeneity in colorectal tumors

BACKGROUND

Recent studies revealed that colorectal tumors are composed of genetically diverse subclones. We aimed to clarify whether the surface microstructures of colorectal tumors are associated with genetic intratumoral heterogeneity (ITH).

METHODS

The surface microstructures (pit patterns) of colorectal tumors were observed using magnifying endoscopy, and biopsy specimens were obtained from respective areas when tumors exhibited multiple pit patterns. A total of 711 specimens from 477 colorectal tumors were analyzed for BRAF, KRAS and TP53 mutations using pyrosequencing and direct sequencing. A panel of cancer-related genes was analyzed through targeted sequencing in 7 tumors.

RESULTS

Colorectal tumors with multiple pit patterns exhibited more advanced pit patterns and higher frequencies of KRAS and/or TP53 mutations than tumors with a single pit pattern. In tumors with multiple pit patterns, mutations were observed as public (common to all areas) or private (specific to certain areas), and private KRAS and/or TP53 mutations were often variable and unrelated to the pit pattern grade. Notably, invasive CRCs frequently exhibited public TP53 mutations, even in adenomatous areas, which is indicative of their early malignant potential. Targeted sequencing revealed additional public and private mutations in tumors with multiple pit patterns, indicating their single clonal origin.

CONCLUSIONS

Our results suggest intratumoral pit pattern variation does not simply reflect the process of colorectal tumor evolution, but instead represents genetically diverse subclones, and this diversity may be associated with malignant potential.

DOT1L inhibition blocks multiple myeloma cell proliferation by suppressing IRF4-MYC signaling

Epigenetic alterations play an important role in the pathogenesis in multiple myeloma, but their biological and clinical relevance is not fully understood. Here, we show that DOT1L, which catalyzes methylation of histone H3 lysine 79, is required for myeloma cell survival. DOT1L expression levels were higher in monoclonal gammopathy of undetermined significance and smoldering multiple myeloma than in normal plasma cells. Treatment with a DOT1L inhibitor induced cell cycle arrest and apoptosis in myeloma cells, and strongly suppressed cell proliferation in vitro. The anti-myeloma effect of DOT1L inhibition was confirmed in a mouse xenograft model. Chromatin immunoprecipitation-sequencing and microarray analysis revealed that DOT1L inhibition downregulated histone H3 lysine 79 dimethylation and expression of IRF4-MYC signaling genes in myeloma cells. In addition, DOT1L inhibition upregulated genes associated with immune responses and interferon signaling. Myeloma cells with histone modifier mutations or lower IRF4/MYC expression were less sensitive to DOT1L inhibition, but with prolonged treatment, anti-proliferative effects were achieved in these cells. Our data suggest that DOT1L plays an essential role in the development of multiple myeloma and that DOT1L inhibition may provide new therapies for myeloma treatment.

Dysregulation of miRNA in chronic hepatitis B is associated with hepatocellular carcinoma risk after nucleos(t)ide analogue treatment

Hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC). Nucleos(t)ide analogue (NA) therapy effectively reduces the incidence of HCC, but it does not completely prevent the disease. Here, we show that dysregulation of microRNAs (miRNAs) is involved in post-NA HCC development. We divided chronic hepatitis B (CHB) patients who received NA therapy into two groups: 1) those who did not develop HCC during the follow-up period after NA therapy (no-HCC group) and 2) those who did (HCC group). miRNA expression profiles were significantly altered in CHB tissues as compared to normal liver, and the HCC group showed greater alteration than the no-HCC group. NA treatment restored the miRNA expression profiles to near-normal in the no-HCC group, but it was less effective in the HCC group. A number of miRNAs implicated in HCC, including miR-101, miR-140, miR-152, miR-199a-3p, and let-7g, were downregulated in CHB. Moreover, we identified CDK7 and TACC2 as novel target genes of miR-199a-3p. Our results suggest that altered miRNA expression in CHB contributes to HCC development, and that improvement of miRNA expression after NA treatment is associated with reduced HCC risk.

Subtypes of the Type II Pit Pattern Reflect Distinct Molecular Subclasses in the Serrated Neoplastic Pathway

BACKGROUND

Colorectal serrated lesions (SLs) are important premalignant lesions whose clinical and biological features are not fully understood.

AIMS

We aimed to establish accurate colonoscopic diagnosis and treatment of SLs through evaluation of associations among the morphological, pathological, and molecular characteristics of SLs.

METHODS

A total of 388 premalignant and 18 malignant colorectal lesions were studied. Using magnifying colonoscopy, microsurface structures were assessed based on Kudo's pit pattern classification system, and the Type II pit pattern was subcategorized into classical Type II, Type II-Open (Type II-O) and Type II-Long (Type II-L). BRAF/KRAS mutations and DNA methylation of CpG island methylator phenotype (CIMP) markers (MINT1, - 2, - 12, - 31, p16, and MLH1) were analyzed through pyrosequencing.

RESULTS

Type II-O was tightly associated with sessile serrated adenoma/polyps (SSA/Ps) with BRAF mutation and CIMP-high. Most lesions with simple Type II or Type II-L were hyperplastic polyps, while mixtures of Type II or Type II-L plus more advanced pit patterns (III/IV) were characteristic of traditional serrated adenomas (TSAs). Type II-positive TSAs frequently exhibited BRAF mutation and CIMP-low, while Type II-L-positive TSAs were tightly associated with KRAS mutation and CIMP-low. Analysis of lesions containing both premalignant and cancerous components suggested Type II-L-positive TSAs may develop into KRAS-mutated/CIMP-low/microsatellite stable cancers, while Type II-O-positive SSA/Ps develop into BRAF-mutated/CIMP-high/microsatellite unstable cancers.

CONCLUSIONS

These results suggest that Type II subtypes reflect distinct molecular subclasses in the serrated neoplasia pathway and that they could be useful hallmarks for identifying SLs at high risk of developing into CRC.

Epigenetic silencing of SMOC1 in traditional serrated adenoma and colorectal cancer

Colorectal sessile serrated adenoma/polyps (SSA/Ps) are well-known precursors of colorectal cancer (CRC) characterized by BRAF mutation and microsatellite instability. By contrast, the molecular characteristics of traditional serrated adenoma (TSAs) are not fully understood. We analyzed genome-wide DNA methylation in TSAs having both protruding and flat components. We identified 11 genes, including SMOC1, methylation of which progressively increased during the development of TSAs. SMOC1 was prevalently methylated in TSAs, but was rarely methylated in SSA/Ps (p < 0.001). RT-PCR and immunohistochemistry revealed that SMOC1 was expressed in normal colon and SSA/Ps, but its expression was decreased in TSAs. Ectopic expression of SMOC1 suppressed proliferation, colony formation and in vivo tumor formation by CRC cells. Analysis of colorectal lesions (n = 847) revealed that SMOC1 is frequently methylated in TSAs, high-grade adenomas and CRCs. Among these, SMOC1 methylation was strongly associated with KRAS mutation and CpG island methylator phenotype (CIMP)-low. These results demonstrate that epigenetic silencing of SMOC1 is associated with TSA development but is rarely observed in SSA/Ps. SMOC1 expression could thus be a diagnostic marker of serrated lesions, and SMOC1 methylation could play a role in neoplastic pathways in TSAs and conventional adenomas.

Evaluation of Urinary DNA Methylation as a Marker for Recurrent Bladder Cancer: A 2-Center Prospective Study

OBJECTIVE

To clarify the clinical utility of urinary DNA methylation for detection of intravesical recurrence of non-muscle invasive BCa (NMIBC), we performed a 2-center prospective study.

PATIENTS AND METHODS

A series of 207 self-voided urine samples were prospectively collected from 132 patients with NMIBC who had undergone transurethral resection of BCa. Methylation of miRNA genes (miR-9-3, miR-124-2, miR-124-3, and miR-137) was analyzed using bisulfite pyrosequencing. The primary end point was detection of intravesical recurrence; the secondary end point was prediction of late recurrence. The number of methylated genes (M-score) or quantitative level of methylation were compared with outcomes.

RESULTS

Twenty-six urine specimens were collected on the same day intravesical recurrence was detected, and 14 were collected from patients whose recurrences were found during the subsequent follow-up period (0-632 days, mean, 342.2 days). For detection of current recurrence, M-scores achieved 61.5% sensitivity and 74.0% specificity, and the area under the ROC curve was 0.71. Regarding prediction of late recurrence, patients with a high M-score (≥3) showed worse recurrence-free survival (P <.01). Multivariate analysis revealed that high M-scores were independently associated with current (P = .028) and late recurrence (P = .026). Elevated levels of urinary DNA methylation were also strongly associated with recurrence and radical cystectomy.

CONCLUSION

Our data suggest that urinary methylation of miRNA genes may be a useful marker for detecting and predicting BCa recurrence.

Downregulation of miR-186 is associated with metastatic recurrence of gastrointestinal stromal tumors

Although dysregulation of microRNAs (miRNAs/miRs) is a common feature of human malignancies, its involvement in gastrointestinal stromal tumors (GISTs) is not fully understood. The present study aimed to identify the miRNAs that perform a role in GIST metastasis. miRNA expression profiles from a series of 32 primary GISTs were analyzed using microarrays, and miR-186 was observed to be downregulated in tumors exhibiting metastatic recurrence. Reverse transcription-quantitative polymerase chain reaction analysis of an independent cohort of 100 primary GISTs revealed that low miR-186 expression is associated with metastatic recurrence and a poor prognosis. Inhibition of miR-186 in GIST-T1 cells promoted cell migration. Gene expression microarray analysis demonstrated that miR-186 inhibition upregulated a set of genes implicated in cancer metastasis, including insulin-like growth factor-binding protein 3, AKT serine/threonine kinase 2, hepatocyte growth factor receptor, CXC chemokine receptor 4 and epidermal growth factor-containing fibulin-like extracellular matrix protein 1. These results suggest that the downregulation of miR-186 is involved in the metastatic recurrence of GISTs, and that miR-186 levels could potentially be a predictive biomarker for clinical outcome.

Computational fluid dynamics study of the pharyngeal airway space before and after mandibular setback surgery in patients with mandibular prognathism

The purpose of this study was to investigate the relationship between the pressure drop in the pharyngeal airway space (ΔP_PAS) and the minimum cross-sectional area (minCSA) of the pharyngeal airway before and after mandibular setback surgery using computational fluid dynamics, in order to prevent iatrogenic obstructive sleep apnoea. Eleven patients with mandibular prognathism underwent bilateral sagittal split osteotomy for mandibular setback. Three-dimensional models of the upper airway were reconstructed from preoperative and postoperative computed tomography images, and simulations were performed using computational fluid dynamics. ΔP_PAS and the minCSA of the pharyngeal airway were calculated, and the relationship between them was evaluated by non-linear regression analysis. In all cases, the minCSA was found at the level of the velopharynx. After surgery, ΔP_PAS increased significantly and the minCSA decreased significantly. The non-linear regression equation expressing the relationship between these variables was ΔP_PAS=3.73×minCSA^-2.06. When the minCSA was <1cm², ΔP_PAS increased greatly. The results of this study suggest that surgeons should consider bimaxillary orthognathic surgery rather than mandibular setback surgery to prevent the development of iatrogenic obstructive sleep apnoea when correcting a skeletal class III malocclusion.

Epigenetic silencing of diacylglycerol kinase gamma in colorectal cancer

Diacylglycerol kinases (DGKs) are important regulators of cell signaling and have been implicated in human malignancies. Whether epigenetic alterations are involved in the dysregulation of DGKs in cancer is unknown, however. We therefore analyzed methylation of the promoter CpG islands of DGK genes in colorectal cancer (CRC) cell lines. We found that DGKG, which encodes DGKγ, was hypermethylated in all CRC cell lines tested (n = 9), but was not methylated in normal colonic tissue. Correspondingly, DGKG expression was suppressed in CRC cell lines but not in normal colonic tissue, and was restored in CRC cells by treatment with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-aza-dC). DGKG methylation was frequently observed in primary CRCs (73/141, 51.8%) and was positively associated with KRAS and BRAF mutations and with the CpG island methylator phenotype (CIMP). DGKG methylation was also frequently detected in colorectal adenomas (89 of 177, 50.3%), which suggests it is an early event during colorectal tumorigenesis. Ectopic expression of wild-type DGKγ did not suppress CRC cell proliferation, but did suppress cell migration and invasion. Notably, both constitutively active and kinase-dead DGKγ mutants exerted inhibitory effects on CRC cell proliferation, migration and invasion, and the wild-type and mutant forms of DGKγ all suppressed Rac1 activity in CRC cells. These data suggest DGKG may play a tumor suppressor role in CRC.

TET1 Depletion Induces Aberrant CpG Methylation in Colorectal Cancer Cells

Aberrant DNA methylation is commonly observed in colorectal cancer (CRC), but the underlying mechanism is not fully understood. 5-hydroxymethylcytosine levels and TET1 expression are both reduced in CRC, while epigenetic silencing of TET1 is reportedly associated with the CpG island methylator phenotype. In the present study, we aimed to clarify the relationship between loss of TET1 and aberrant DNA methylation in CRC. Stable TET1 knockdown clones were established using Colo320DM cells, which express high levels of TET1, and HCT116 cells, which express TET1 at a level similar to that in normal colonic tissue. Infinium HumanMethylation450 BeadChip assays revealed increased levels of 5-methylcytosine at more than 10,000 CpG sites in TET1-depleted Colo320DM cells. Changes in DNA methylation were observed at various positions within the genome, including promoters, gene bodies and intergenic regions, and the altered methylation affected expression of a subset of genes. By contrast, TET1 knockdown did not significantly affect DNA methylation in HCT116 cells. However, TET1 depletion was associated with attenuated effects of 5-aza-2’-deoxycytidine on gene expression profiles in both cell lines. These results suggest that loss of TET1 may induce aberrant DNA methylation and may attenuate the effect of 5-aza-2’-deoxycytidine in CRC cells.

Substrate-borne vibrations induce behavioral responses in the leaf-dwelling cerambycid, Paraglenea fortunei

Many insects utilize substrate-borne vibrations as a source of information for recognizing mates or predators. Among various substrates, plant leaves are commonly used for transmitting and receiving vibrational information. However, little is known about the utilization of vibrations by leaf-dwelling insects, especially coleopteran beetles. We conducted two experiments to examine the response of the leaf-dwelling cerambycid beetle, Paraglenea fortunei, to substrate-borne vibrations. We recorded and analyzed vibrations of host plant leaves from four different sources: wind (0.5 m/s), a beetle during landing, a walking beetle, and a beetle walking in the wind (0.5 m/s). We then measured the behavioral thresholds, the lowest amplitudes that induce behavioral responses, from beetles walking and resting on horizontal and vertical substrates with pulsed vibrations ranging from 20 Hz to 1 kHz. The vibrational characteristics of biotic and abiotic stimuli clearly differed. Beetle-generated vibrations (landing, walking, and walking in the wind) were broadly high in the low-frequency components above ∼30 Hz, while wind-generated vibrations showed a dominant peak at ∼30 Hz and a steep decrease thereafter. Among four situations, beetles walking on horizontal substrates showed lowest thresholds to vibrations of 75-500 Hz, which are characteristic of beetle-generated vibrations. Given that P. fortunei beetles are found on horizontal leaf surfaces of the host plant, vibrations transmitted though horizontal substrates may induce a strong freeze response in walking beetles to detect conspecifics or heterospecifics. Our findings provide evidence that leaf-dwelling beetles can discriminate among biotic and abiotic factors via differences in vibrational characteristics.

Cervicofacial subcutaneous emphysema associated with dental laser treatment

Cervicofacial subcutaneous emphysema is a rare complication of dental procedures. Although most cases of emphysema occur incidentally with the use of a high-speed air turbine handpiece, there have been some reports over the past decade of cases caused by dental laser treatment. Emphysema as a complication caused by the air cooling spray of a dental laser is not well known, even though dental lasers utilize compressed air just as air turbines and syringes do. In this study, we comprehensively reviewed cases of emphysema attributed to dental laser treatment that appeared in the literature between January 2001 and September 2012, and we included three such cases referred to us. Among 13 cases identified in total, nine had cervicofacial subcutaneous and mediastinal emphysema. Compared with past reviews, the incidence of mediastinal emphysema caused by dental laser treatment was higher than emphysema caused by dental procedure without dental laser use. Eight patients underwent CO2 laser treatment and two underwent Er:YAG laser treatment. Nine patients had emphysema following laser irradiation for soft tissue incision. Dentists and oral surgeons should be cognizant of the potential risk for iatrogenic emphysema caused by the air cooling spray during dental laser treatment and ensure proper usage of lasers.

Visualization of Flow Instabilities for High Density Polyethylene

Two typical flow instabilities of “Shark Skin” and “Melt Fracture” for high density polyethylene were investigated in this report. Experimental measurements were carried out methodically in a wide flow region from the reservoir (entry region) to the die land with a specific slit die. Especially the flow pattern was visualized with a high speed camera and the frequency of the flow instability was analyzed. Corresponding to the visualization analysis, the pressure fluctuation in the slit die and the surface roughness at the die exit were measured simultaneously and these frequency characteristics were analyzed with a FFT (Fast Fourier Transform) analyzer. As for “Shark Skin” region, the irregularity of the surface roughness in the broad frequency band was recognized at the die exit. In spite of this surface roughness, the pressure fluctuation and the fluctuation of the flow pattern at the wall vicinity in the die land were not observed. These results indicate that “Shark Skin” occurs at the die exit. As for “Melt Fracture” region, the periodical oscillation of the flow pattern and the periodical pressure fluctuation which corresponded to the periodical distortion of the extrudate was recognized in the die land. However the periodical oscillation of the flow pattern and the periodical pressure fluctuation could not be recognized in the reservoir (entry region of the die land). These results indicate that “Melt Fracture” is initiated at the die entry and occurs in the die land. Consequently it is clarified that “Shark Skin” occurs at the die exit and the flow instability which lead to “Melt Fracture” is initiated at the die entry and occurs in the die land.

HLA and SNP haplotype mapping in the Japanese population

The genes that encode the human leukocyte antigen (HLA) class I and II molecules are highly polymorphic and located in the major histocompatibility complex (MHC) region, where there is a high density of immune-related genes. Numerous studies have identified disease susceptibility in this region; however, interpretation of the results is complicated because of the strong linkage disequilibrium (LD) among HLA alleles and single-nucleotide polymorphisms (SNPs). In this study, we evaluated the correlation between the HLA alleles of 6 loci (HLA-A, C, B, DRB1, DQB1 and DPB1) and 6502 SNPs within 8 Mb of the extended MHC region using 92 Japanese subjects to identify SNP single loci or haplotypes that tag HLA alleles. We found a total of 39 HLA alleles that showed strong LD (r(2)≥0.8) with SNPs, including 11 non-synonymous SNPs in non-HLA genes. In addition, we identified several SNP haplotypes in strong LD (r(2)≥0.8) with eight HLA alleles, which do not possess tag SNPs. Our detailed list of tag SNPs and haplotypes could be utilized for a better understanding of the results obtained by association studies in the Japanese population and for the characterization of the differences in LD structures between races.

Tuning of the fluorescence wavelength of CdTe quantum dots with 2 nm resolution by size-selective photoetching

Photoetching of CdTe nanocrystals was applied to thiol-capped CdTe quantum dots (QDs) to control their fluorescence wavelength. CdTe QDs with a high quantum yield (49%) were synthesized in aqueous solution, and they were successfully photoetched in strong alkaline (pH = 13.5) conditions. When monochromatic light was used, size-selective photoetching could be conducted; the photoetching proceeded until the band gap energy of the CdTe QDs increased to the energy corresponding to the wavelength of the irradiating light. As a result, a good linear relationship was obtained between the wavelength of the irradiating light and that of the fluorescence peak. The resulting CdTe QDs exhibited a fluorescence peak with an FWHM value as small as 23.5 nm, indicating preparation of highly monodispersed nanocrystals. The high quantum yield (ca. 45%) was maintained after the photoetching. Very fine tuning of the fluorescence wavelength with 2 nm resolution was achieved by changing the wavelength of the irradiating light by 2 nm. Theoretical calculation of the quantum size effects (effective mass approximation) predicts that a difference in the band gap fluorescence wavelength of 2 nm corresponds to a change in particle diameter of ca. 0.02 nm.

Local Intra-Arterial Fibrinolysis in Acute Basilar Artery Occlusion

Acute basilar artery (BA) occlusion is typically associated with poor outcome; however newer diagnostic and treatment modalities have the potential to improve prognosis. In this study, six patients with acute BA occlusion were followed and the effectiveness of local intra-arterial fibrinolysis (LIF) and subsequent percutaneous transluminal angioplasty (PTA) with a balloon catheter were assessed. Of the six patients with BA occlusion observed in this study, two had extended brain stem infarction on diffusion weighted image (DWI) and were treated conservatively. The other four patients received LIF at an average of 5.2 hours from occlusion onset. Three of these four patients received additional PTA with compliant balloon catheters. All four of the patients who received LIF achieved recanalization of the BA trunk and showed a favorable clinical outcome. These findings suggest that LIF is beneficial for selected patients with BA occlusion and that successful recanalization is indicative of a good prognosis. Because of the poor prognosis associated with conservative therapy, we conclude that LIF should be attempted even for comatose patients or in cases of prolonged occlusion time.

Lead optimization of [(S)-γ-(arylamino)prolyl]thiazolidine focused on γ-substituent: Indoline compounds as potent DPP-IV inhibitors

Dipeptidyl peptidase IV (DPP-IV) inhibitors are looked to as a potential new antidiabetic agent class. A series of [(S)-gamma-(arylamino)prolyl]thiazolidine compounds in which the electrophilic nitrile is removed are chemically stable DPP-IV inhibitors. To discover a structure for the gamma-substituent of the proline moiety more suitable for interacting with the S(2) pocket of DPP-IV, optimization focused on the gamma-substituent was carried out. The indoline compound 22e showed a DPP-IV-inhibitory activity 100-fold more potent than that of the prolylthiazolidine 10 and comparable to that of NVP-DPP728. It also displayed improved inhibitory selectivity for DPP-IV over DPP8 and DPP9 compared to compound 10. Indoline compounds such as 22e have a rigid conformation with double restriction of the aromatic moiety by proline and indoline structures to promote interaction with the binding site in the S(2) pocket of DPP-IV. The double restriction effect provides a potent inhibitory activity which compensates for the decrease in activity caused by removing the electrophilic nitrile.

Carotid-compression technique for the insertion of guiding catheters

Inserting a guiding catheter into a tortuous artery for neurointerventional procedures can be difficult. In our technique, the carotid artery is manually compressed to stabilize and/or straighten the inserted wire before advancing the guiding catheter. Although this technique is not risk-free and care must be taken to avoid vascular injury by excessive compression, it is useful for the insertion of a guiding catheter into the carotid artery.

[(S)-γ-(Arylamino)prolyl]thiazolidine compounds as a novel series of potent and stable DPP-IV inhibitors

Dipeptidyl peptidase-IV (DPP-IV) inhibitors, or glucagon-like peptide-1 (GLP-1) enhancers, are looked to as a potential new class of antidiabetic agents. In particular, potent and long-acting inhibitors might offer advantages in exploiting DPP-IV inhibition. The series of [(S)-gamma-(arylamino)prolyl]-(S)-2-cyanopyrrolidine compounds on which we reported previously has a highly potent inhibitory activity but seemed to be unstable in neutral aqueous solution. Here, we describe [(S)-gamma-(arylamino)prolyl]thiazolidine compounds as a novel series of potent and stable DPP-IV inhibitors. They are the thiazolidine analogs of [(S)-gamma-(arylamino)prolyl]-(S)-2-cyanopyrrolidine but with the electrophilic nitrile removed to improve chemical stability in aqueous solution. Of the compounds investigated in the present study, the [((S)-gamma-3,4-dicyanophenylamino)prolyl]thiazolidine 12 m was the most potent. The structure-activity relationship (SAR) of the gamma-substituent in the proline moiety of the thiazolidide was similar to that obtained with the (S)-2-cyanopyrrolidide. The gamma-substituent in the proline moiety of both the (S)-2-cyanopyrrolidide and the thiazolidide may engage with the S(2) binding pocket of DPP-IV and thereby achieve hydrophobic interaction in the same manner. Based on pharmacokinetic experiments in rats, the representative compound 11, which displayed high oral bioavailability (BA=83.9%) and long half-life in plasma (t(1/2)=5.27 h), was found to have an excellent pharmacokinetic profile.

1-((S)-γ-Substituted prolyl)-(S)-2-cyanopyrrolidine as a novel series of highly potent DPP-IV inhibitors

1-(Gamma-substituted prolyl)-(S)-2-cyanopyrrolidines were designed based on the predicted binding mode of the known DPP-IV inhibitor NVP-DPP728 and evaluated for their inhibitory activity. In structure-activity relationship study at the gamma-position of proline, it became clear that compounds bearing (S)-stereochemistry were 20-fold more potent than the antipode. Of these compounds, the (3,4-dicyanophenyl)amino- and (3-chloro-4-cyanophenyl)amino-derivatives showed the highest inhibitory activity.

Antihypertensive effect of gamma-amino butyric acid enriched soy products in spontaneously hypertensive rats

The effect of gamma-amino butyric acid (GABA)-enriched soybean on blood pressure was investigated in male spontaneously hypertensive rats. Ten-week-old rats were given diets containing graded levels of GABA-enriched soybean powder for 8 weeks. The systolic blood pressure in rats fed 0.15% GABA diet was significantly lower at 1st week and maintained lower values for 4 weeks as compared with 0% GABA controls. No effect on blood pressure was found in those of 0.03 and 0.3% GABA. The results suggest that there exist appropriate dietary GABA level to get the blood pressure lowering effect.

Development of Four-Crawler Multilink Mobile Robot MOIRA for Searching Debris

Finding victims in disaster debris is the priority in search-and-rescue operations. Attempts to use robots and other mobile devices instead of humans involve such problems as 1) operating when pressed from 4 sides, 2) difficulty in continuing operation or becoming inoperable when overturned, and 3) robot size restricting mobility on uneven terrain. We developed a robot overcoming these problems and surveying debris too closely packed and/or dangerous for human workers to enter. MOIRA, a linked crawler consisting of 4 linked modules, each having crawlers on 4 sides enabling the robot to solve the above problems and improve navigation on uneven terrain. We discuss the linked crawler and its 4-crawler systemuse and qualitatively demonstrate its feasibility. From experiments on operational performance, we quantitatively evaluated its feasibility.

Daily bowel movements and Escherichia coli O157 infection

The usual bowel habits of 259 school age children before the large outbreak of E coli O157 infection in Sakai City in the summer of 1996 were investigated. A daily morning movement and/or frequent bowel movements may be a protective factor against infection, while being constipated contributed to a worsening of symptoms.

Clinical utility of capillary polymerase chain reaction for diagnosis of Cytomegalovirus pneumonia

The purpose of this retrospective study was to assess the diagnostic efficacy of CMV DNA detection by capillary PCR in patients with interstitial pneumonia. Of 882 samples taken from 363 patients, 317 were obtained from sputum, 94 from BAL fluid, 291 from blood and 180 from urine. PCR for CMV was positive in 58 samples (6.6%), with positive detection for 6.9% of sputum, 10.6% of BAL fluid, 4.1% of blood and 7.8% of urine samples. CMV pneumonia was diagnosed retrospectively in 34 (9.4%) of the 363 patients by demonstration of CMV antigen-positive cytomegalic inclusion bodies in lung tissue sections. The positive and negative predictive values were 100% (10/10) and 98.8% (83/84) for the BAL fluid samples and 95.5% (21/22) and 99.7% (294/295) for the sputum samples, respectively. Clinical sensitivity and specificity were 90.9% (10/11) and 100% (83/83) for the BAL fluid samples and 95.5% (21/22) and 99.7% (294/295) for the sputum samples, respectively. However, the blood and urine samples showed poor clinical sensitivity and low positive predictive values. We suggest that the use of capillary PCR for BAL fluid and sputum samples is very useful for diagnosing CMV pneumonia in patients with interstitial pneumonia in whom CMV pneumonia is suspected.

CD3+CD4-CD8-TCR-alphabeta+ T-cell lymphoma with clinical features of primary effusion lymphoma: an autopsy case

We report an unusual case of T-cell lymphoma presenting as ascites. A 72-year-old HIV-negative woman was admitted to our hospital for abdominal discomfort associated with increasing abdominal girth over the course of 1 month. Physical examination showed a tense and distended abdomen and edema of the lower extremities. There was no hepatosplenomegaly or lymphadenopathy. A computed tomographic scan of the abdomen and chest showed massive ascites and pleural effusions, but there was no evidence of tumor masses or lymph node enlargement. The cytospin prepared from the peritoneal fluid was hypercellular and composed of a population of monotonous, large cells containing fine chromatin. No herpesvirus-8 (HHV-8) DNA was detected by polymerase chain reaction in the cells. Immunohistochemistry showed the neoplastic cells to be CD3+, CD4, CD7+. CD8-, CD34-, CD56, and TCR-alphabeta+. Repeated cytogenetic studies showed common abnormalities of del(1) (p11p22), +i(7)(ql0), and t(11:14)(q23;q11). The morphologic and immunologic findings were suggestive of peripheral T-cell lymphoma (PTCL), unspecified. This case suggests that some PTCLs with clonal chromosomal aberrations can exhibit peculiar serosal spreading in the absence of HHV-8 infection.

Interleukin-4 is needed for the infection of monocytes by human cytomegalovirus

OBJECTIVE

We studied the ability of human cytomegalovirus (HCMV) to infect peripheral blood mononuclear cells (PBMC) pretreated with or without Th2-cytokine interleukin-4 (IL-4) in vitro.

METHODS

Adherent cells and nonadherent cells were obtained from PBMC. We inoculated these cells with HCMV at concentrations ranging from 0 to 10 ng/ml of IL-4. Immediate-early antigen-1 (IE-1) and glycoprotein H (gH) mRNAs were detected using the reverse-transcription polymerase chain reaction.

RESULTS

IE-1 and gH mRNAs could be detected in monocytes pretreated with IL-4. In contrast, no IE-1 mRNA was detected in monocytes pretreated without IL-4. We tested whether higher infectious titers could result in the infection of monocytes whether or not they were pretreated with IL-4. However, no IE-1 mRNA was detected in the monocytes not pretreated with IL-4. To elucidate how HCMV-infected monocytes affect lung tissue, human embryonic lung fibroblasts MRC-5 were cocultured with HCMV-infected monocytes. The cytopathic effects of HCMV were observed microscopically and was confirmed by direct immunoperoxidase staining with a human monoclonal antibody against the HCMV IE-1.

CONCLUSION

Our data strongly suggest that the ability of HCMV to infect monocytes may correlate with the presence of IL-4.

Taurine inhibits development of atherosclerotic lesions in apolipoprotein E-deficient mice

1. The effects of taurine on the development of atherosclerotic lesions were investigated in apolipoprotein (apo) E-deficient mice, an animal model with severe hypercholesterolaemia and extensive atherosclerosis. These mice were fed a normal laboratory chow containing 2% taurine for 12 weeks. 2. Serum total cholesterol was significantly elevated after 12 weeks treatment with taurine. This elevation was due to increases in very low-density lipoprotein- and low-density lipoprotein-cholesterol. 3. Despite such effects on serum lipoproteins, analysis using en face oil red O staining revealed that taurine reduced the area of arterial lipid accumulation by 28%, as measured quantitatively as an index of atherosclerosis. Histological examination also demonstrated a decrease in the size of aortic lesions in taurine-treated mice. 4. Serum levels of thiobarbituric acid reactive substances (TBARS) in apoE-deficient mice were higher than in normolipidaemic C57BL/6J mice. Serum TBARS levels were significantly decreased by 12 weeks treatment of apoE-deficient mice with taurine. 5. Thus, taurine prevents the formation of atherosclerotic lesions, independently of serum cholesterol levels, and the results suggest that the anti-oxidative effects of taurine are related to its anti-atherosclerotic actions.