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Background and Aims The serrated colorectal carcinoma ( CRC) as proposed to arise from serrated adenoma ( SA) is characterized by upregulation of HIF1α, suppression of PTCH or Eph B2, loss of DNA repair proteins, and BRAF mutation. The aim of this study was to evaluate alterations of these candidates involved in the serrated pathway in colorectal polyps. Methods We analyzed immunoreactivity of these proteins, methylation of PTCH and Eph B2, and mutation of BRAF and Kras in sessile SAs ( SSAs; n = 32), traditional SAs ( n = 28), hyperplastic polyps ( HPs; n = 24), and conventional adenomas ( ADs; n = 21). Results Increase of nuclear HIF1α expression was more frequent in SA than HP, but less frequent in SA than AD ( P < 0.001). Increase of PTCH expression was not found in SSA or HP, but was evident in about half of traditional SA and all AD ( P < 0.001). Decrease of EphB2 expression was more prominent in SA than HP or AD ( P ≤ 0.005). Loss of hMLH1 and MGMT expression were most frequent in SSA ( P < 0.001). Loss of hMSH2 showed more pronounced in SA and HP than AD ( P ≤ 0.004). Methylations of PTCH and Eph B2 were rare in all categories. BRAF mutation harbored frequently in SA, but not AD; only AD harbored Kras mutation. Conclusions This work provides evidence of similarity of HIF1α, Eph B2 or DNA repair proteins expression, and BRAF mutation in serrated CRCs and their precursors, especially SSA, compared with AD and HP. [ABSTRACT FROM AUTHOR]

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a rare variant of typical squamous cell carcinoma (SCC) associated with poor survival. A characteristic feature is nuclear accumulation of β-catenin, without a mutation of the gene. We studied the methylation status of Wnt antagonist genes, such as secreted frizzled-related protein (sFRP) gene family members, Wnt inhibitory factor-1 (WIF-1), Dickkopf-1 (Dkk-1), and human Dapper protein-1 (HDPR-1), and alterations of the APC, Axin1, and Axin2 genes in 30 cases of esophageal BSCC. β-catenin and sFRP (sFRP-1, sFRP-2, sFRP-4, sFRP-5) protein expression was examined by immunohistochemistry. APC, Axin1, and Axin2 gene mutations were detected in 3, 2, and 2 cases, respectively, and 6 cases (20 %) harbored at least 1 alteration in these genes. Methylation of the sFRP-2 promoter region was observed in all cases, and methylation was frequent in sFRP-1 and sFRP-5, but infrequent in Dkk-1, WIF-1, sFRP-4, and HDPR-1. sFRP-2 expression was almost completely absent in 25 cases (83 %), consistent with the methylation status. Nuclear accumulation of β-catenin was observed in all cases. sFRP-5 expression was associated with a low nuclear β-catenin labeling index. These results show that sFRP-2 is a target gene of hypermethylation in esophageal BSCC and suggest that sFRP-2 might contribute to BSCC tumorigenesis through the Wnt/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

Graminaceous plants release mugineic acid family phytosiderophores ( MAs) to acquire iron from the soil. Here, we show that deoxymugineic acid ( DMA) secretion from rice roots fluctuates throughout the day, and that vesicles accumulate in roots before MAs secretion. We developed transgenic rice plants that express rice nicotianamine ( NA) synthase ( NAS) 2 ( OsNAS2) fused to synthetic green fluorescent protein ( sGFP) under the control of its own promoter. In root cells, OsNAS2- sGFP fluorescence was observed in a dot-like pattern, moving dynamically within the cell. This suggests that these vesicles are involved in NA and DMA biosynthesis. A tyrosine motif and a di-leucine motif, which have been reported to be involved in cellular transport, are conserved in all identified NAS proteins in plants. OsNAS2 mutated in the tyrosine motif showed NAS activity and was localized to the vesicles; however, these vesicles stuck together and did not move. On the other hand, OsNAS2 mutated in the di-leucine motif lost NAS activity and did not localize to these vesicles. The amounts of NA and DMA produced and the amount of DMA secreted by OsNAS2- sGFP plants were significantly higher than in non-transformants and domain-mutated lines, suggesting that OsNAS2- sGFP, but not the mutated forms, was functional in vivo. Overall, the localization of NAS to vesicles and the transport of these vesicles are crucial steps in NA synthesis, leading to DMA synthesis and secretion in rice. [ABSTRACT FROM AUTHOR]

Aims Basal-like breast cancer (BLBC) is characterized by aggressive behaviour; its genesis is the perturbation of DNA repair as a consequence of BRCA1 methylation or mutation. We comparatively evaluated alterations of DNA repair proteins and p53 between BLBC and non-BLBC cases. Methods and results Tumour sections from 104 BLBC and 89 non-BLBC patients were immunostained for hMLH1, hMSH2, MGMT, BRCA1 and p53. Methylation status of DNA repair genes was analysed by methylation-specific PCR, and p53 mutation was examined by direct sequencing. Immunoreactive levels of hMLH1 and MGMT were lower in BLBC, whereas the levels of hMSH2 and p53 were higher, compared to non-BLBC ( P ≤ 0.014). Reduced expression of hMLH1 [hazard ratio (HR) 5.26, P = 0.001] and preserved expression of MGMT (HR 2.58, P = 0.039) proved to be independent predictors of poor survival in BLBC patients. DNA repair genes were methylated in approximately 20-40% of BLBCs without a significant relationship between their methylation and p53 mutation. BRCA1 methylation was associated with the loss of its protein expression ( P = 0.004). MGMT methylation was linked to larger tumour size ( P < 0.001). Conclusions Perturbations of the DNA repair system might be different between BLBC and non-BLBC. Alterations of hMLH1 and MGMT appear important for tumour progression and survival in BLBC patients. [ABSTRACT FROM AUTHOR]

Phytic acid (inositol hexakisphosphate [InsP6]) is the storage compound of phosphorus in seeds. As phytic acid binds strongly to metallic cations, it also acts as a storage compound of metals. To understand the mechanisms underlying metal accumulation and localization in relation to phytic acid storage, we applied synchrotron-based x-ray microfluorescence imaging analysis to characterize the simultaneous subcellular distribution of some mineral elements (phosphorus, calcium, potassium, iron, zinc, and copper) in immature and mature rice (Oryza sativa) seeds. This fine-imaging method can reveal whether these elements colocalize. We also determined their accumulation patterns and the changes in phosphate and InsP6 contents during seed development. While the InsP6 content in the outer parts of seeds rapidly increased during seed development, the phosphate contents of both the outer and inner parts of seeds remained low. Phosphorus, calcium, potassium, and iron were most abundant in the aleurone layer, and they colocalized throughout seed development. Zinc was broadly distributed from the aleurone layer to the inner endosperm. Copper localized outside the aleurone layer and did not colocalize with phosphorus. From these results, we suggest that phosphorus translocated from source organs was immediately converted to InsP6 and accumulated in aleurone layer cells and that calcium, potassium, and iron accumulated as phytic acid salt (phytate) in the aleurone layer, whereas zinc bound loosely to InsP6 and accumulated not only in phytate but also in another storage form. Copper accumulated in the endosperm and may exhibit a storage form other than phytate. [ABSTRACT FROM AUTHOR]

Summary: Basaloid squamous cell carcinoma of the esophagus is a rare variant of squamous cell carcinoma. We reviewed 878 cases of esophageal squamous cell carcinoma and detected 22 cases (3%) of basaloid squamous cell carcinoma. These tumors and stage-matched paired conventional squamous cell carcinomas were investigated for clinicopathologic features and immunoreactivity of cytokeratin subtypes, p53, B-cell lymphoma 2 (bcl-2), β-catenin, and epidermal growth factor receptor. Molecular aberrations in p53, CTNNB1 (the gene encoding β-catenin), and epidermal growth factor receptor (EGFR) were also determined. Patients with basaloid squamous cell carcinomas demonstrated a 5-year survival rate of 42%, significantly worse than those with well-differentiated squamous cell carcinoma (P < .01). Histologically, solid nests with central necrosis and a cribriform pattern were identified in almost all (≥95%) cases, and ductal differentiation was less frequent (45%) but associated with significantly better survival (P < .05). Compared with conventional squamous cell carcinomas, the basaloid squamous cell carcinomas were less immunoreactive for cytokeratin 14, cytokeratin 903, and membranous β-catenin (P < .01-.001) but more reactive for bcl-2, nuclear β-catenin, epidermal growth factor receptor, and Ki-67 (P < .05-.001). Direct sequencing showed mutations of p53 (36%), EGFR (14%), but not CTNNB1; fluorescent in situ hybridization detected amplification of the epidermal growth factor receptor gene (22%). In basaloid squamous cell carcinomas, low-level expression of cytokeratin 14/cytokeratin 903 and mutations of p53 and EGFR had a significant influence on worse survival (P < .05-.001). We conclude that the esophageal basaloid squamous cell carcinoma, a neoplasm with particularly aggressive biologic behavior, should be differentiated from conventional squamous cell carcinomas. In this context, immunohistochemical assessment of several markers might provide a useful adjunct diagnostic tool. Aberrations of p53 and epidermal growth factor receptor genes are possibly involved in progression of esophageal basaloid squamous cell carcinoma. [Copyright &y& Elsevier]

Background: Liver dysfunction in adult hypopituitary patients with GH deficiency (GHD) has been reported and an increased prevalence of nonalcoholic fatty liver disease (NAFLD) has been suggested. Objective: The objective of the present study was to elucidate the pathophysiology of the liver in adult hypopituitary patients with GHD. Patients and methods:We recruited 69 consecutive Japanese adult hypopituitary patients with GHD and examined the prevalence of NAFLD by ultrasonography and nonalcoholic steatohepatitis (NASH) by liver biopsy. Patients had been given routine replacement therapy except for GH. We compared these patients with healthy age-, gender-, and BMI-matched controls. We further analyzed the effect of GH replacement therapy on liver function, inflammation and fibrotic markers, and histological changes. Results: The prevalence of NAFLD in hypopituitary patients with GHD was significantly higher than in controls (77 vs 12%, P!0.001). Of 16 patients assessed by liver biopsy, 14 (21%) patients were diagnosed with NASH. GH replacement therapy significantly reduced serum liver enzyme concentrations in the patients and improved the histological changes in the liver concomitant with reduction in fibrotic marker concentrations in patients with NASH. Conclusions: Adult hypopituitary patients with GHD demonstrated a high NAFLD prevalence. The effect of GH replacement therapy suggests that the NAFLD is predominantly attributable to GHD. [ABSTRACT FROM AUTHOR]

Abstract: Background: Excessive oxidative stress plays a causal role in various diseases such as diabetes, hypertension, atherosclerosis, and heart failure. Acromegaly is a pathological condition associated with excess growth hormone (GH) and insulin-like growth factor-I (IGF-I) and a high prevalence of diabetes, hypertension, atherosclerosis, and heart failure; resulting in premature death. We hypothesized that these conditions may be associated with increased oxidative stress. Objective and methods: We explored the oxidative stress levels in the serum and tissues of GH-transgenic rats as an animal model for acromegaly. We also measured the oxidative stress levels in the serum of patients with acromegaly and age-, sex-, and BMI-matched control subjects. We examined the effects of GH and IGF-I on reactive oxygen species (ROS) production in C2C12 myocytes. Results: The levels of an oxidative stress marker, serum thiobarbituric acid reactive substances (TBARS) were increased in the GH-transgenic rats. Further, tissue oxidative stress damage was enhanced in the cardiomyocytes and vascular smooth muscle cells in the aorta of the GH-transgenic rats. In addition, serum TBARS levels and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were increased in acromegaly in humans. IGF-I but not GH induced ROS production in C2C12 myocytes in vitro. Conclusions: These data indicate that the increased levels of IGF-I are associated with enhanced oxidative stress in rats and humans. In addition, increased ROS may play an important role in the complications and premature death in acromegaly. [Copyright &y& Elsevier]