High Activities of BACE1 in Brains with Mild Cognitive Impairment

β-Amyloid (Aβ) peptides that accumulate in Alzheimer disease are generated from the β-amyloid precursor protein (βAPP) by cleavages by β-secretase BACE1 and by presenilin-dependent γ-secretase activities. Very few data document a putative cross-talk between these proteases and the regulatory mechanisms underlying such interaction. We show that presenilin deficiency lowers BACE1 maturation and affects both BACE1 activity and promoter transactivation. The specific γ-secretase inhibitor DFK167 triggers the decrease of BACE1 activity in wild-type but not in presenilin-deficient fibroblasts. This decrease is also elicited by catalytically inactive γ-secretase. The overexpression of APP intracellular domain (AICD), the γ/ϵ-secretase-derived C-terminal product of β-amyloid precursor protein, does not modulate BACE1 activity or promoter transactivation in fibroblasts and does not alter BACE1 expression in AICD transgenic brains of mice. A DFK167-sensitive increase of BACE1 activity is observed in cells overexpressing APPϵ (the N-terminal product of βAPP generated by ϵ-secretase cleavage harboring the Aβ domain but lacking the AICD sequence), suggesting that the production of Aβ could account for the modulation of BACE1. Accordingly, we show that HEK293 cells overexpressing wild-type βAPP exhibit a DFK167-sensitive increase in BACE1 promoter transactivation that is increased by the Aβ-potentiating Swedish mutation. This effect was mimicked by exogenous application of Aβ42 but not Aβ40 or by transient transfection of cDNA encoding Aβ42 sequence. The IκB kinase inhibitor BMS345541 prevents Aβ-induced BACE1 promoter transactivation suggesting that NFκB could mediate this Aβ-associated phenotype. Accordingly, the overexpression of wild-type or Swedish mutated βAPP does not modify the transactivation of BACE1 promoter constructs lacking NFκB-responsive element. Furthermore, APP/β-amyloid precursor protein-like protein deficiency does not affect BACE1 activity and expression. Overall, these data suggest that physiological levels of endogenous Aβ are not sufficient per se to modulate BACE1 promoter transactivation but that exacerbated Aβ production linked to wild-type or Swedish mutated βAPP overexpression modulates BACE1 promoter transactivation and activity via an NFκB-dependent pathway.

S4-01-01: Identification of subgroups of Alzheimer disease

Adult hippocampal neurogenesis in Alzheimer's disease: A roadmap to clinical relevance.

Proteolytic processing of the amyloid precursor protein by alpha-secretase prevents formation of the amyloid beta-peptide (Abeta), which is the main constituent of amyloid plaques in brains of Alzheimer disease (AD) patients. alpha-Secretase activity is decreased in AD, and overexpression of the alpha-secretase ADAM10 (a disintegrin and metalloprotease 10) in an AD animal model prevents amyloid pathology. ADAM10 has a 444-nucleotide-long, very GC-rich 5'-untranslated region (5'-UTR) with two upstream open reading frames. Because similar properties of 5'-UTRs are found in transcripts of many genes, which are regulated by translational control mechanisms, we asked whether ADAM10 expression is translationally controlled by its 5'-UTR. We demonstrate that the 5'-UTR of ADAM10 represses the rate of ADAM10 translation. In the absence of the 5'-UTR, we observed a significant increase of ADAM10 protein levels in HEK293 cells, whereas mRNA levels were not changed. Moreover, the 5'-UTR of ADAM10 inhibits translation of a luciferase reporter in an in vitro transcription/translation assay. Successive deletion of the first half of the ADAM10 5'-UTR revealed a striking increase in ADAM10 protein expression in HEK293 cells, suggesting that this part of the 5'-UTR contains inhibitory elements for translation. Moreover, we detect an enhanced alpha-secretase activity and consequently reduced Abeta levels in the conditioned medium of HEK293 cells expressing both amyloid precursor protein and a 5'-UTR-ADAM10 deletion construct lacking the first half of the 5'-UTR. Thus, we provide evidence that the 5'-UTR of ADAM10 may have an important role for post-transcriptional regulation of ADAM10 expression and consequently Abeta production.

Intrinsic Connectivity Identifies the Hippocampus as a Main Crossroad between Alzheimer’s and Semantic Dementia-Targeted Networks

Cell Death and Learning Impairment in Mice Caused by in Vitro Modified Pro-NGF Can Be Related to Its Increased Oxidative Modifications in Alzheimer Disease

Caspase-3 Is Enriched in Postsynaptic Densities and Increased in Alzheimer's Disease

Is γ-secretase a beneficial inactivating enzyme of the toxic APP C-terminal fragment C99?

Germline stem cells: toward the regeneration of spermatogenesis

There is a significant flux of the neurotoxic oxysterol 27-hydroxycholesterol (27OHC) from the circulation across the blood-brain barrier. Because there is a correlation between 27OHC and cholesterol in the circulation and lipoprotein-bound cholesterol does not pass the blood-brain barrier, we have suggested that 27OHC may mediate the effects of hypercholesterolemia on the brain. We previously demonstrated a modest accumulation of 27OHC in brains of patients with sporadic Alzheimer's disease (AD), consistent with a role of 27OHC as a primary pathogenetic factor. We show here that there is a 4-fold accumulation of 27OHC in different regions of the cortexes of patients carrying the Swedish amyloid precursor protein (APPswe) 670/671 mutation. The brain levels of sitosterol and campesterol were not significantly different in the AD patients compared with the controls, suggesting that the blood-brain barrier was intact in the AD patients. We conclude that accumulation of 27OHC is likely to be secondary to neurodegeneration, possibly a result of reduced activity of CYP7B1, the neuronal enzyme responsible for metabolism of 27OHC. We discuss the possibility of a vicious circle in the brains of the patients with familial AD whereby neurodegenerative changes cause an accumulation of 27OHC that further accelerates neurodegeneration.

Mild cognitive impairment (MCI) is considered to be a prodromal stage of Alzheimer’s disease (AD), which is the most common type of dementia. Although MCI is a common clinical manifestation in the elderly, the pathology and molecular mechanisms are not fully understood. Oxylipins are a major class of lipid-derived signaling mediators, which have been implicated in the pathology of MCI and AD. In this study, we investigated the changes of oxylipin profiles in plasma of MCI patients. We performed a targeted liquid chromatography—mass spectrometry analysis to quantify 49 oxylipins and 4 polyunsaturated fatty acids in plasma samples of 60 clinically diagnosed MCI patients and 56 age- and gender-matched cognitively normal individuals. We found that the levels of linoleic acid (LA) and 7 oxylipins were significantly altered in MCI patients when compared to the controls. Notably, oxylipins synthesized through 5-lipoxygenase (5-LOX) and cytochrome P450 (CYP450) pathways of arachidonic acid (AA) or LA were elevated in MCI patients, which is in accordance with previously reports that oxylipins from the same pathways were increased in the brain tissues of AD and MCI patients, suggesting the potential correlations of oxylipin changes in 5-LOX and CYP450 pathways between the peripheral blood and the brain tissues in MCI and AD patients. This study is the first report on plasma oxylipin profiles in MCI patients, and disease-relevant changes of oxylipins and oxylipin pathways were identified. The results represent potentially an efficient method to monitor certain oxylipin changes in the brain tissues of MCI or AD patients.

Production of the amyloid beta-peptide (Abeta) via sequential proteolytic cleavage of the amyloid precursor protein by beta- and gamma-secretases is strongly implicated in the pathogenesis of Alzheimer disease. The beta-secretase that executes the first cleavage event is a transmembrane aspartyl protease known as beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1). BACE1 pre-mRNA is alternatively spliced through the use of alternative splice sites in exons 3 and 4, although the significance of these splicing events is unclear. Here, we quantitatively measured relative levels of BACE1 transcripts and identified a novel splice variant of BACE1. We found a subtle but significant difference in BACE1 splicing between brain and pancreas, indicating the cellular environment can affect BACE1 alternative splicing. Furthermore, we have shown that BACE1 proteins translated from alternatively spliced transcripts have dramatically reduced beta-secretase activity and promotion of BACE1 alternative splicing reduces Abeta production. These findings illustrate the importance of BACE1 alternative splicing in affecting the level of Abeta produced in cells and suggest that targeting regulation of BACE1 alternative splicing is a potential therapeutic strategy for lowering beta-secretase activity.

Kingdom-Agnostic Metagenomics and the Importance of Complete Characterization of Enteric Microbial Communities

It has been suggested that mild cognitive impairment (MCI) patients deteriorate faster than the healthy elderly population and have an increased risk of developing dementia. Certain blood molecular biomarkers have been identified as prognostic markers in Alzheimer's disease (AD). The present study was aimed to assess the status of the platelet amyloid precursor protein (APP) metabolism in MCI and AD subjects and establish to what extent any variation could have a prognostic value suggestive of predictive AD in MCI patients. Thirty-four subjects diagnosed with MCI and 45 subjects with AD were compared to 28 healthy elderly individuals for assessing for protein levels of APP, β-APP cleaving enzyme 1 (BACE1), presenilin 1 (PS1) and a disintegrin and metalloproteinase-10 (ADAM-10) by western blot, and for the enzyme activities of BACE1 and γ-secretase by using specific fluorogenic substrates, in samples of platelets. A similar pattern in the healthy elderly and MCI patients was found for BACE1 and PS1 levels. A reduction of APP levels in MCI and AD patients compared with healthy elderly individuals was found. Augmented levels of ADAM-10 in both MCI and AD were displayed in comparison with age-matched control subjects. The ratio ADAM-10/BACE1 was higher for the MCI group versus AD group. Whereas BACE1 and PS1 levels were only increased in AD regarding to controls, BACE1 and γ-secretase activities augmented significantly in both MCI and AD groups. Finally, differences and similarities between MCI and AD patients were observed in several markers of platelet APP processing. Larger sample sets from diverse populations need to be analyzed to define a signature for the presence of MCI or AD pathology and to early detect AD at the MCI stage.

For many decades, cell-free nucleic acids have been known to be present in peripheral blood. Several studies have identified tumor-specific and/or tumor-associated alterations in the circulating nucleic acids of patients with various cancers. In recent years, cell-free microRNA (miRNA) have been stably detected in the plasma and serum, like other molecules; their presence in the blood has attracted the attention of researchers due to their potential use as valuable blood biomarkers.1Schwarzenbach H. Hoon D.S. Pantel K. Cell-free nucleic acids as biomarkers in cancer patients.Nat Rev Cancer. 2011; 11: 426-437Crossref PubMed Scopus (2199) Google Scholar MiRNAs are short, noncoding RNAs that play important roles in various physiologic and developmental processes. The mature miRNAs are produced from long primary transcripts through 2 sequential cleavage steps. The long primary miRNA transcript is cleaved by the Drosha complex in the nucleus, generating intermediate precursor miRNA. Precursor miRNA is transported by exportin-5 from the nucleus into the cytoplasm, and then subjected to further cleavage by a Dicer RNAase III enzyme, generating a short double-strand miRNA. One strand (guided strand) of mature miRNA is then incorporated into the RNA-induced silencing complex and subsequently hybridize to the 3′-untranslated region of their target mRNAs to repress translation or degrade these mRNAs. Thus, a single miRNA can influence the expression of hundreds of genes and allow them to function in a coordinated manner. Therefore, miRNAs have been implicated as key molecules in all cellular processes. Numerous studies have shown that alterations in miRNA expression correlate with various diseases, including the development and progression of cancer, and some miRNAs can function as oncogenes or tumor suppressors. These findings have opened up a new and interesting field in the diagnosis of cancer and the treatments of cancer patients. Mitchell et al2Mitchell P.S. Parkin R.K. Kroh E.M. et al.Circulating microRNAs as stable blood-based markers for cancer detection.Proc Natl Acad Sci U S A. 2008; 105: 10513-10518Crossref PubMed Scopus (6792) Google Scholar first demonstrated that circulating miRNAs had the potential to be new biomarkers in patients with solid cancers. In recent years, several papers have demonstrated that circulating miRNAs can also be detected in the peripheral blood of patients with digestive tract cancers. Although the origins and physiologic functions of cell-free miRNAs in the blood remain to be fully elucidated, a noninvasive assay for miRNAs should be developed to exploit these molecules as potential diagnostic and prognostic biomarkers. This assay undoubtedly contributes to an improvement in the clinical outcomes of cancer patients. In this article, we review the current state of biological and clinical research regarding circulating miRNAs of digestive tract cancer patients and discuss the future perspectives. It has been theorized that the necrosis and the apoptosis of tumor cells are the main sources of cell-free nucleic acids in the plasma and serum. However, several recent studies have demonstrated that extracellular nucleic acids, especially miRNAs, occur not only through cell lysis but also through active secretion.1Schwarzenbach H. Hoon D.S. Pantel K. Cell-free nucleic acids as biomarkers in cancer patients.Nat Rev Cancer. 2011; 11: 426-437Crossref PubMed Scopus (2199) Google Scholar, 3Valadi H. Ekström K. Bossios A. et al.Exosome-mediated transfer of mRNAs and microRNAs is a novel mechanism of genetic exchange between cells.Nat Cell Biol. 2007; 9: 654-659Crossref PubMed Scopus (9739) Google Scholar, 4Kosaka N. Iguchi H. Yoshioka Y. et al.Secretory mechanisms and intercellular transfer of microRNAs in living cells.J Biol Chem. 2010; 285: 17442-17452Abstract Full Text Full Text PDF PubMed Scopus (1591) Google Scholar, 5Pigati L. Yaddanapudi S.C. Iyengar R. et al.Selective release of microRNA species from normal and malignant mammary epithelial cells.PLoS One. 2010; 5: e13515Crossref PubMed Scopus (497) Google Scholar Cell-derived endogenous miRNAs are present in the blood in a remarkably stable form that is protected from endogenous RNase activity. In contrast, synthetic exogenous miRNAs are rapidly degraded when added directly to the plasma.2Mitchell P.S. Parkin R.K. Kroh E.M. et al.Circulating microRNAs as stable blood-based markers for cancer detection.Proc Natl Acad Sci U S A. 2008; 105: 10513-10518Crossref PubMed Scopus (6792) Google Scholar Kosaka et al4Kosaka N. Iguchi H. Yoshioka Y. et al.Secretory mechanisms and intercellular transfer of microRNAs in living cells.J Biol Chem. 2010; 285: 17442-17452Abstract Full Text Full Text PDF PubMed Scopus (1591) Google Scholar clearly demonstrated that a subset of miRNAs was packaged into exosome vesicles and released through a ceramide-dependent secretory mechanism. Arroyo et al6Arroyo J.D. Chevillet J.R. Kroh E.M. et al.Argonaute2 complexes carry a population of circulating microRNAs independent of vesicles in human plasma.Proc Natl Acad Sci U S A. 2011; 108: 5003-5008Crossref PubMed Scopus (2672) Google Scholar systematically investigated circulating miRNAs in the plasma and serum using differential centrifugation and size-exclusion chromatography techniques. This group demonstrated ≥2 populations of circulating miRNAs in the plasma and serum and discovered agonaute-2, a key effector protein involved in miRNA-mediated silencing as an miRNA carrier in the blood.6Arroyo J.D. Chevillet J.R. Kroh E.M. et al.Argonaute2 complexes carry a population of circulating microRNAs independent of vesicles in human plasma.Proc Natl Acad Sci U S A. 2011; 108: 5003-5008Crossref PubMed Scopus (2672) Google Scholar In addition, high-density lipoprotein has been described as an alternative transporter of extracellular miRNAs in human plasma.7Vickers K.C. Palmisano B.T. Shoucri B.M. et al.MicroRNAs are transported in plasma and delivered to recipient cells by high-density lipoproteins.Nat Cell Biol. 2011; 13: 423-433Crossref PubMed Scopus (2256) Google Scholar All circulating miRNAs, regardless of whether they are incorporated into protein complexes and/or cell-derived microvesicles, seem to be adequately protected against the degradation caused by the abundant RNases in human plasma and serum. Indeed, the extracellular miRNAs in the plasma and serum are extremely stable under severe conditions, such as extended storage and exposure to multiple freeze–thaw cycles.2Mitchell P.S. Parkin R.K. Kroh E.M. et al.Circulating microRNAs as stable blood-based markers for cancer detection.Proc Natl Acad Sci U S A. 2008; 105: 10513-10518Crossref PubMed Scopus (6792) Google Scholar Regarding the composition of circulating miRNAs, Pigati et al5Pigati L. Yaddanapudi S.C. Iyengar R. et al.Selective release of microRNA species from normal and malignant mammary epithelial cells.PLoS One. 2010; 5: e13515Crossref PubMed Scopus (497) Google Scholar investigated the difference between extracellular and cellular miRNAs using epithelial cell lines and concluded that the release of miRNAs did not necessarily reflect the abundance of miRNAs in the cell of origin. Kosaka et al4Kosaka N. Iguchi H. Yoshioka Y. et al.Secretory mechanisms and intercellular transfer of microRNAs in living cells.J Biol Chem. 2010; 285: 17442-17452Abstract Full Text Full Text PDF PubMed Scopus (1591) Google Scholar also demonstrated that some specific miRNAs were expressed to a greater extent in cell-derived exosomes compared with their donor cells.4Kosaka N. Iguchi H. Yoshioka Y. et al.Secretory mechanisms and intercellular transfer of microRNAs in living cells.J Biol Chem. 2010; 285: 17442-17452Abstract Full Text Full Text PDF PubMed Scopus (1591) Google Scholar Moreover, other groups demonstrated that the non–vesicle-associated miRNA profiles within protein complexes were distinctly different from the purified, exosomes-associated miRNA profiles.6Arroyo J.D. Chevillet J.R. Kroh E.M. et al.Argonaute2 complexes carry a population of circulating microRNAs independent of vesicles in human plasma.Proc Natl Acad Sci U S A. 2011; 108: 5003-5008Crossref PubMed Scopus (2672) Google Scholar These findings indicate that intracellular miRNAs are exported to the extracellular environment through a selective secretion mechanism. Interestingly, recent studies have demonstrated that extracellular miRNAs not only circulate in stable forms, but can also be incorporated into other surrounding and distant recipient cells in which they fulfill distinctive functions.8Skog J. Würdinger T. van Rijn S. et al.Glioblastoma microvesicles transport RNA and proteins that promote tumour growth and provide diagnostic biomarkers.Nat Cell Biol. 2008; 10: 1470-1476Crossref PubMed Scopus (3954) Google Scholar, 9Rechavi O. Erlich Y. Amram H. et al.Cell contact–dependent acquisition of cellular and viral nonautonomously encoded small RNAs.Genes Dev. 2009; 23: 1971-1979Crossref PubMed Scopus (100) Google Scholar, 10Zernecke A. Bidzhekov K. Noels H. et al.Delivery of microRNA-126 by apoptotic bodies induces CXCL12-dependent vascular protection.Sci Signal. 2009; 2: ra81Crossref PubMed Scopus (1130) Google Scholar, 11Kosaka N. Iguchi H. Ochiya T. Circulating microRNA in body fluid: a new potential biomarker for cancer diagnosis and prognosis.Cancer Sci. 2010; 101: 2087-2092Crossref PubMed Scopus (1144) Google Scholar, 12Pegtel D.M. Cosmopoulos K. Thorley–Lawson D.A. et al.Functional delivery of viral miRNAs via exosomes.Proc Natl Acad Sci U S A. 2010; 107: 6328-6333Crossref PubMed Scopus (1309) Google Scholar, 13Kosaka N. Iguchi H. Yoshioka Y. et al.Competitive Interactions of Cancer Cells and Normal Cells via Secretory MicroRNAs.J Biol Chem. 2012; 287: 1397-1405Abstract Full Text Full Text PDF PubMed Scopus (235) Google Scholar Rechavi et al9Rechavi O. Erlich Y. Amram H. et al.Cell contact–dependent acquisition of cellular and viral nonautonomously encoded small RNAs.Genes Dev. 2009; 23: 1971-1979Crossref PubMed Scopus (100) Google Scholar demonstrated that functional signals spread across cell boundaries between immune cells in a contact-dependent manner. Pegtel et al12Pegtel D.M. Cosmopoulos K. Thorley–Lawson D.A. et al.Functional delivery of viral miRNAs via exosomes.Proc Natl Acad Sci U S A. 2010; 107: 6328-6333Crossref PubMed Scopus (1309) Google Scholar reported that Epstein–Barr virus miRNAs were secreted from infected B cells and were present in both the circulation and noninfected non-B cells. This group also demonstrated that miRNAs were transferred from infected to noninfected cells in vivo and were functional (upon transfer via exosomes) in primary monocyte-derived dendritic cells. Other groups have shown that miR-126 in apoptotic bodies derived from atherosclerotic endothelial cells induces the CXCL-12–dependent vascular protection process in recipient vascular cells.10Zernecke A. Bidzhekov K. Noels H. et al.Delivery of microRNA-126 by apoptotic bodies induces CXCL12-dependent vascular protection.Sci Signal. 2009; 2: ra81Crossref PubMed Scopus (1130) Google Scholar There have also been some reports regarding miRNA-mediated intercellular communication in a neoplastic environment. Skog et al8Skog J. Würdinger T. van Rijn S. et al.Glioblastoma microvesicles transport RNA and proteins that promote tumour growth and provide diagnostic biomarkers.Nat Cell Biol. 2008; 10: 1470-1476Crossref PubMed Scopus (3954) Google Scholar reported that microvesicles that housed miRNAs derived from glioblastomas were taken up by and fulfilled functions in human brain microvascular endothelial cells in culture. Kosaka et al4Kosaka N. Iguchi H. Yoshioka Y. et al.Secretory mechanisms and intercellular transfer of microRNAs in living cells.J Biol Chem. 2010; 285: 17442-17452Abstract Full Text Full Text PDF PubMed Scopus (1591) Google Scholar also demonstrated that miR-146a, which is a tumor-suppressive miRNA in prostate cancer, significantly knocked down the target ROCK1 protein expression and decreased cell proliferation in a recipient prostate cancer cell line.4Kosaka N. Iguchi H. Yoshioka Y. et al.Secretory mechanisms and intercellular transfer of microRNAs in living cells.J Biol Chem. 2010; 285: 17442-17452Abstract Full Text Full Text PDF PubMed Scopus (1591) Google Scholar Their subsequent paper demonstrated that a variety of tumor-suppressive miRNAs were secreted by a normal adult prostatic epithelial cell line, and among these secretory miRNAs, miR-143 could inhibit growth exclusively in cancer cells both in vitro and in vivo.13Kosaka N. Iguchi H. Yoshioka Y. et al.Competitive Interactions of Cancer Cells and Normal Cells via Secretory MicroRNAs.J Biol Chem. 2012; 287: 1397-1405Abstract Full Text Full Text PDF PubMed Scopus (235) Google Scholar Other groups found that the let-7 miRNA family was abundant in the extracellular fractions derived from a metastatic gastric cancer (GC) cell line, but not those derived from a low metastatic parental cell line, and it has been speculated that some cancer cells maintain their oncogenesis via specific extracellular miRNAs.14Ohshima K. Inoue K. Fujiwara A. et al.Let-7 microRNA family is selectively secreted into the extracellular environment via exosomes in a metastatic gastric cancer cell line.PLoS One. 2010; 5: e13247Crossref PubMed Scopus (515) Google Scholar On the other hand, exosomes released from neoplastic cells have been reported to suppress immune surveillance, and cell-free miRNAs contained within the exosomes may be responsible for the immunosuppression systems.15Zhang H.G. Grizzle W.E. Exosomes and cancer: a newly described pathway of immune suppression.Clin Cancer Res. 2011; 17: 959-964Crossref PubMed Scopus (233) Google Scholar These findings support the presence of miRNA-mediated intercellular communication in the normal cellular environment and the tumor environment (Figure 1) . Several methods can be used for extracting miRNAs; however, efficient protocols with high reproducibility should be utilized for the extraction of circulating miRNAs owing to the small amounts present in the plasma and serum. Commercial extraction kits that utilize glass fiber filters in the purification process have been widely used for clinical blood samples, and there are several methods for quantification. A polymerase chain reaction (PCR)-based technique using a stem-loop reverse-transcriptase (RT) primer has been widely used for determining quantity. A microarray assay, which can analyze hundreds of miRNAs simultaneously, has also been utilized for the identification of a specific marker among many circulating miRNAs. Recent advances in technology allow for the use of an oligonucleotide array to quantify the amount of circulating miRNAs without the need for PCR. Most recently, researchers have identified circulating miRNAs as new diagnostic markers in patients with cancer using direct sequencing methods16Brase J.C. Wuttig D. Kuner R. et al.Serum microRNAs as non–invasive biomarkers for cancer.Mol Cancer. 2010; 9: 306Crossref PubMed Scopus (366) Google Scholar (Table 117Zhang C. Wang C. Chen X. et al.Expression profile of microRNAs in serum: a fingerprint for esophageal squamous cell carcinoma.Clin Chem. 2010; 56: 1871-1879Crossref PubMed Scopus (289) Google Scholar, 18Komatsu S. Ichikawa D. Takeshita H. et al.Circulating microRNAs in plasma of patients with oesophageal squamous cell carcinoma.Br J Cancer. 2011; 105: 104-111Crossref PubMed Scopus (233) Google Scholar, 19Tsujiura M. Ichikawa D. Komatsu S. et al.Circulating microRNAs in plasma of patients with gastric cancers.Br J Cancer. 2010; 102: 1174-1179Crossref PubMed Scopus (578) Google Scholar, 20Liu R. Zhang C. Hu Z. et al.A five-microRNA signature identified from genome–wide serum microRNA expression profiling serves as a fingerprint for gastric cancer diagnosis.Eur J Cancer. 2011; 47: 784-791Abstract Full Text Full Text PDF PubMed Scopus (392) Google Scholar, 21Liu H. Zhu L. Liu B. et al.Genome-wide microRNA profiles identify miR-–378 as a serum biomarker for early detection of gastric cancer.Cancer Lett. 2012; 316: 196-203Crossref PubMed Scopus (234) Google Scholar, 22Konishi H. Ichikawa D. Komatsu S. et al.Detection of gastric cancer–associated microRNAs on microRNA microarray comparing pre- and post-operative plasma.Br J Cancer. 2012; 106: 740-747Crossref PubMed Scopus (165) Google Scholar, 23Ng E.K. Chong W.W. Jin H. et al.Differential expression of microRNAs in plasma of patients with colorectal cancer: a potential marker for colorectal cancer screening.Gut. 2009; 58: 1375-1381Crossref PubMed Scopus (1055) Google Scholar, 24Huang Z. Huang D. Ni S. et al.Plasma microRNAs are promising novel biomarkers for early detection of colorectal cancer.Int J Cancer. 2010; 127: 118-126Crossref PubMed Scopus (868) Google Scholar, 25Wang L.G. Gu J. Serum is a promising novel marker for early detection of colorectal 2012; PubMed Scopus Google Scholar, H. Zhang L. et al.Circulating plasma is a novel biomarker for metastatic cancer and One. 2011; PubMed Scopus Google Scholar, Huang et al.Circulating directly from plasma is a potential diagnostic and prognostic marker of colorectal cancer and is with 2010; PubMed Scopus Google Scholar, Y. Kosaka N. M. et as a potential diagnostic marker for 2009; PubMed Scopus Google Scholar, Zhang K. H. et al.Circulating microRNAs as biomarkers for 2011; PubMed Scopus Google Scholar, Wang H. et al.Serum as for in with B One. 2011; PubMed Scopus Google Scholar, J. C. X. et al.Circulating and in patients with or 2011; PubMed Scopus Google Scholar, J. L. X. Hu J. et al.Plasma to 2011; PubMed Scopus Google Scholar, Y. H. H. et al.Circulating as a novel biomarker for 2012; 56: Full Text Full Text PDF PubMed Scopus Google Scholar, J. Y. X. et al.Serum microRNA as a potential marker for Sci. 2011; PubMed Scopus Google Scholar, J. Chen J. et al.MicroRNAs in plasma of patients as novel blood-based biomarkers of Res. 2009; 2: PubMed Scopus Google Scholar, A. N. et and and in with circulating and Res. 2010; PubMed Scopus Google Scholar, Huang X. H. et al.Circulating as a novel marker in 2010; PubMed Scopus Google Scholar, S. K. Chen et expressed miRNAs in the plasma may provide a signature for J Res. 2010; Google Scholar, N. A. et and serum microRNAs in the and in patients with One. 2011; PubMed Scopus Google Scholar, R. Komatsu S. Ichikawa D. et diagnostic of circulating in plasma of patients with J Cancer. 2011; 105: PubMed Scopus Google Scholar, J. J. Y. et of plasma microRNAs with serum for early detection of cancer.Int J Cancer. 2011; Scopus Google miRNAs in cell or other C. Wang C. Chen X. et al.Expression profile of microRNAs in serum: a fingerprint for esophageal squamous cell carcinoma.Clin Chem. 2010; 56: 1871-1879Crossref PubMed Scopus (289) Google S. Ichikawa D. Takeshita H. et al.Circulating microRNAs in plasma of patients with oesophageal squamous cell carcinoma.Br J Cancer. 2011; 105: 104-111Crossref PubMed Scopus (233) Google M. Ichikawa D. Komatsu S. et al.Circulating microRNAs in plasma of patients with gastric cancers.Br J Cancer. 2010; 102: 1174-1179Crossref PubMed Scopus (578) Google or other R. Zhang C. Hu Z. et al.A five-microRNA signature identified from genome–wide serum microRNA expression profiling serves as a fingerprint for gastric cancer diagnosis.Eur J Cancer. 2011; 47: 784-791Abstract Full Text Full Text PDF PubMed Scopus (392) Google in the H. Zhu L. Liu B. et al.Genome-wide microRNA profiles identify miR-–378 as a serum biomarker for early detection of gastric cancer.Cancer Lett. 2012; 316: 196-203Crossref PubMed Scopus (234) Google H. Ichikawa D. Komatsu S. et al.Detection of gastric cancer–associated microRNAs on microRNA microarray comparing pre- and post-operative plasma.Br J Cancer. 2012; 106: 740-747Crossref PubMed Scopus (165) Google E.K. Chong W.W. Jin H. et al.Differential expression of microRNAs in plasma of patients with colorectal cancer: a potential marker for colorectal cancer screening.Gut. 2009; 58: 1375-1381Crossref PubMed Scopus (1055) Google Z. Huang D. Ni S. et al.Plasma microRNAs are promising novel biomarkers for early detection of colorectal cancer.Int J Cancer. 2010; 127: 118-126Crossref PubMed Scopus (868) Google in the L.G. Gu J. Serum is a promising novel marker for early detection of colorectal 2012; PubMed Scopus Google cancer H. Zhang L. et al.Circulating plasma is a novel biomarker for metastatic cancer and One. 2011; PubMed Scopus Google in the Huang et al.Circulating directly from plasma is a potential diagnostic and prognostic marker of colorectal cancer and is with 2010; PubMed Scopus Google in the Y. Kosaka N. M. et as a potential diagnostic marker for 2009; PubMed Scopus Google Zhang K. H. et al.Circulating microRNAs as biomarkers for 2011; PubMed Scopus Google Wang H. et al.Serum as for in with B One. 2011; PubMed Scopus Google not for J. C. X. et al.Circulating and in patients with or 2011; PubMed Scopus Google in the J. L. X. Hu J. et al.Plasma to 2011; PubMed Scopus Google Y. H. H. et al.Circulating as a novel biomarker for 2012; 56: Full Text Full Text PDF PubMed Scopus Google J. Y. X. et al.Serum microRNA as a potential marker for Sci. 2011; PubMed Scopus Google in the J. Chen J. et al.MicroRNAs in plasma of patients as novel blood-based biomarkers of Res. 2009; 2: PubMed Scopus Google A. N. et and and in with circulating and Res. 2010; PubMed Scopus Google in the Huang X. H. et al.Circulating as a novel marker in 2010; PubMed Scopus Google S. K. Chen et expressed miRNAs in the plasma may provide a signature for J Res. 2010; Google N. A. et and serum microRNAs in the and in patients with One. 2011; PubMed Scopus Google R. Komatsu S. Ichikawa D. et diagnostic of circulating in plasma of patients with J Cancer. 2011; 105: PubMed Scopus Google in the J. J. Y. et of plasma microRNAs with serum for early detection of cancer.Int J Cancer. 2011; Scopus Google microRNA colorectal direct esophageal gastric polymerase chain in the in a new microRNA colorectal direct esophageal gastric polymerase chain Zhang et C. Wang C. Chen X. et al.Expression profile of microRNAs in serum: a fingerprint for esophageal squamous cell carcinoma.Clin Chem. 2010; 56: 1871-1879Crossref PubMed Scopus (289) Google Scholar have investigated the serum miRNA profiles of patients with esophageal squamous cell using miRNAs using direct this group identified serum miRNAs and as biomarkers. The under the for the miRNAs were for serum tumor and patients in the early of the could be from using the miRNA C. Wang C. Chen X. et al.Expression profile of microRNAs in serum: a fingerprint for esophageal squamous cell carcinoma.Clin Chem. 2010; 56: 1871-1879Crossref PubMed Scopus (289) Google Scholar plasma from group also the plasma expression of miRNAs that were to be with the development of on found that the plasma of to be in patients in the and the were significantly in compared with A of the in plasma was the of an in serum tumor which that circulating miRNAs may be for diagnosis of in S. Ichikawa D. Takeshita H. et al.Circulating microRNAs in plasma of patients with oesophageal squamous cell carcinoma.Br J Cancer. 2011; 105: 104-111Crossref PubMed Scopus (233) Google Scholar However, there have been reports regarding circulating miRNAs for the other group first reported the of circulating miRNAs as biomarkers in patients with miRNAs and which have been reported to be in as miRNAs and their in plasma using In the plasma of these miRNAs the tumor miRNA and were significantly in patients in the also found that the plasma of these miRNAs were significantly in compared with M. Ichikawa D. Komatsu S. et al.Circulating microRNAs in plasma of patients with gastric cancers.Br J Cancer. 2010; 102: 1174-1179Crossref PubMed Scopus (578) Google Scholar Liu et R. Zhang C. Hu Z. et al.A five-microRNA signature identified from genome–wide serum microRNA expression profiling serves as a fingerprint for gastric cancer diagnosis.Eur J Cancer. 2011; 47: 784-791Abstract Full Text Full Text PDF PubMed Scopus (392) Google Scholar have investigated the serum miRNA profiles of patients with using miRNAs using direct this group identified serum miRNAs and as biomarkers for found that the expression of serum miRNAs was with the tumor and the for the miRNAs were for serum tumor R. Zhang C. Hu Z. et al.A five-microRNA signature identified from genome–wide serum microRNA expression profiling serves as a fingerprint for gastric cancer diagnosis.Eur J Cancer. 2011; 47: 784-791Abstract Full Text Full Text PDF PubMed Scopus (392) Google Scholar Other groups have investigated serum miRNA profiles using miRNA and concluded that was the biomarker for detection in the serum, with and the expression in primary was compared with normal H. Zhu L. 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