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Showing papers in "The Journal of Pathology in 2009"


Journal ArticleDOI
TL;DR: A new, enlightened era of experimentation and clinical trials has been initiated with xenogenic and allogeneic MSCs.
Abstract: Adult marrow-derived mesenchymal stem cells (MSCs) are able to differentiate into bone, cartilage, muscle, marrow stroma, tendon-ligament, fat and other connective tissues. The questions can be asked, what do MSCs do naturally and where is the MSC niche? New insight and clinical experience suggest that MSCs are naturally found as perivascular cells, summarily referred to as pericytes, which are released at sites of injury, where they secrete large quantities of bioactive factors that are both immunomodulatory and trophic. The trophic activity inhibits ischaemia-caused apoptosis and scarring while stimulating angiogenesis and the mitosis of tissue intrinsic progenitor cells. The immunomodulation inhibits lymphocyte surveillance of the injured tissue, thus preventing autoimmunity, and allows allogeneic MSCs to be used in a variety of clinical situations. Thus, a new, enlightened era of experimentation and clinical trials has been initiated with xenogenic and allogeneic MSCs.

1,061 citations


Journal ArticleDOI
TL;DR: The results suggest that specific miRNAs may be directly involved in cancer metastasis and that they may represent a novel diagnostic tool in the characterization of metastatic cancer gene targets.
Abstract: Small non-coding microRNAs (miRNAs) contribute to cancer development and progression, and are differentially expressed in normal tissues and cancers. However, the specific role of miRNAs in the metastatic process is still unknown. To seek a specific miRNA expression signature characterizing the metastatic phenotype of solid tumours, we performed a miRNA microarray analysis on 43 paired primary tumours (ten colon, ten bladder, 13 breast, and ten lung cancers) and one of their related metastatic lymph nodes. We identified a metastatic cancer miRNA signature comprising 15 overexpressed and 17 underexpressed miRNAs. Our results were confirmed by qRT-PCR analysis. Among the miRNAs identified, some have a well-characterized association with cancer progression, eg miR-10b, miR-21, miR-30a, miR-30e, miR-125b, miR-141, miR-200b, miR-200c, and miR-205. To further support our data, we performed an immunohistochemical analysis for three well-defined miRNA gene targets (PDCD4, DHFR, and HOXD10 genes) on a small series of paired colon, breast, and bladder cancers, and one of their metastatic lymph nodes. We found that the immunohistochemical expression of these targets significantly follows the corresponding miRNA deregulation. Our results suggest that specific miRNAs may be directly involved in cancer metastasis and that they may represent a novel diagnostic tool in the characterization of metastatic cancer gene targets.

484 citations


Journal ArticleDOI
TL;DR: The present data suggest that this virus is a major cause of amyloid plaques and hence probably a significant aetiological factor in Alzheimer's disease, and point to the usage of antiviral agents to treat the disease and possibly of vaccination to prevent it.
Abstract: The brains of Alzheimer's disease sufferers are characterized by amyloid plaques and neurofibrillary tangles. However, the cause(s) of these features and those of the disease are unknown, in sporadic cases. We previously showed that herpes simplex virus type 1 is a strong risk factor for Alzheimer's disease when in the brains of possessors of the type 4 allele of the apolipoprotein E gene (APOE-epsilon4), and that beta-amyloid, the main component of plaques, accumulates in herpes simplex virus type 1-infected cell cultures and mouse brain. The present study aimed to elucidate the relationship of the virus to plaques by determining their proximity in human brain sections. We used in situ polymerase chain reaction to detect herpes simplex virus type 1 DNA, and immunohistochemistry or thioflavin S staining to detect amyloid plaques. We discovered a striking localization of herpes simplex virus type 1 DNA within plaques: in Alzheimer's disease brains, 90% of the plaques contained the viral DNA and 72% of the DNA was associated with plaques; in aged normal brains, which contain amyloid plaques at a lower frequency, 80% of plaques contained herpes simplex virus type 1 DNA but only 24% of the viral DNA was plaque-associated (p < 0.001). We suggest that this is because in aged normal individuals, there is a lesser production and/or greater removal of beta-amyloid (Abeta), so that less of the viral DNA is seen to be associated with Abeta in the brain. Our present data, together with our finding of Abeta accumulation in herpes simplex virus type 1-infected cells and mouse brain, suggest that this virus is a major cause of amyloid plaques and hence probably a significant aetiological factor in Alzheimer's disease. They point to the usage of antiviral agents to treat the disease and possibly of vaccination to prevent it.

347 citations


Journal ArticleDOI
TL;DR: Both plaque angiogenesis and plaque hypoxia represent novel targets for non‐invasive imaging of plaques at risk for rupture, potentially permitting early diagnosis and/or risk prediction of patients with atherosclerosis in the near future.
Abstract: The clinical complications of atherosclerosis are caused by thrombus formation, which in turn results from rupture of an unstable atherosclerotic plaque. The formation of microvessels (angiogenesis) in an atherosclerotic plaque contributes to the development of plaques, increasing the risk of rupture. Microvessel content increases with human plaque progression and is likely stimulated by plaque hypoxia, reactive oxygen species and hypoxia-inducible factor (HIF) signalling. The presence of plaque hypoxia is primarily determined by plaque inflammation (increasing oxygen demand), while the contribution of plaque thickness (reducing oxygen supply) seems to be minor. Inflammation and hypoxia are almost interchangeable and both stimuli may initiate HIF-driven angiogenesis in atherosclerosis. Despite the scarcity of microvessels in animal models, atherogenesis is not limited in these models. This suggests that abundant plaque angiogenesis is not a requirement for atherogenesis and may be a physiological response to the pathophysiological state of the arterial wall. However, the destruction of the integrity of microvessel endothelium likely leads to intraplaque haemorrhage and plaques at increased risk for rupture. Although a causal relation between the compromised microvessel structure and atherogenesis or between angiogenic stimuli and plaque angiogenesis remains tentative, both plaque angiogenesis and plaque hypoxia represent novel targets for non-invasive imaging of plaques at risk for rupture, potentially permitting early diagnosis and/or risk prediction of patients with atherosclerosis in the near future.

345 citations


Journal ArticleDOI
TL;DR: Genetic aberrations that activate the ERK/MAP kinase pathway in 100% of posterior fossa pilocytic astrocytomas are reported, with a high frequency of gene fusions between KIAA1549 and BRAF among these tumours.
Abstract: We report genetic aberrations that activate the ERK/MAP kinase pathway in 100% of posterior fossa pilocytic astrocytomas, with a high frequency of gene fusions between KIAA1549 and BRAF among these tumours. These fusions were identified from analysis of focal copy number gains at 7q34, detected using Affymetrix 250K and 6.0 SNP arrays. PCR and sequencing confirmed the presence of five KIAA1549-BRAF fusion variants, along with a single fusion between SRGAP3 and RAF1. The resulting fusion genes lack the auto-inhibitory domains of BRAF and RAF1, which are replaced in-frame by the beginning of KIAA1549 and SRGAP3, respectively, conferring constitutive kinase activity. An activating mutation of KRAS was identified in the single pilocytic astrocytoma without a BRAF or RAF1 fusion. Further fusions and activating mutations in BRAF were identified in 28% of grade II astrocytomas, highlighting the importance of the ERK/MAP kinase pathway in the development of paediatric low-grade gliomas.

267 citations


Journal ArticleDOI
TL;DR: The findings suggest a possible hazard for the clinical use of MSCs; however, they also offer new opportunities to study early genetic events in osteosarcoma genesis and, more importantly, to modulate these events and record the effect on tumour progression.
Abstract: High-grade osteosarcoma is characterized by extensive genetic instability, thereby hampering the identification of causative gene mutations and understanding of the underlying pathological processes It lacks a benign precursor lesion and reports on associations with hereditary predisposition or germline mutations are uncommon, despite the early age of onset Here we demonstrate a novel comprehensive approach for the study of premalignant stages of osteosarcoma development in a murine mesenchymal stem cell (MSC) system that formed osteosarcomas upon grafting By parallel functional and phenotypic analysis of normal MSCs, transformed MSCs and derived osteosarcoma cells, we provide substantial evidence for a MSC origin of osteosarcoma In a stepwise approach, using COBRA-FISH karyotyping and array CGH in different passages of MSCs, we identified aneuploidization, translocations and homozygous loss of the cdkn2 region as the key mediators of MSC malignant transformation We then identified CDKN2A/p16 protein expression in 88 osteosarcoma patients as a sensitive prognostic marker, thereby bridging the murine MSCs model to human osteosarcoma Moreover, occasional reports in patients mention osteosarcoma formation following bone marrow transplantation for an unrelated malignancy Our findings suggest a possible hazard for the clinical use of MSCs; however, they also offer new opportunities to study early genetic events in osteosarcoma genesis and, more importantly, to modulate these events and record the effect on tumour progression This could be instrumental for the identification of novel therapeutic strategies, since the success of the current therapies has reached a plateau phase

258 citations


Journal ArticleDOI
TL;DR: The tight association of MCV with MCC, the clonal pattern ofMCV integration, and the expression of the viral oncoproteins strongly support a causative role for MCV in the tumour process.
Abstract: Merkel cell carcinoma (MCC), a skin tumour with neuroendocrine features, was recently found to be associated with a new type of human polyomavirus, called Merkel cell virus (MCV). We investigated the specificity of this association as well as a causal role of MCV in oncogenesis. DNA and RNA from ten cases of MCC were analysed using PCR and RT-PCR. DNA from 1241 specimens of a wide range of human tumours was also analysed. The DIPS technique was used to identify the integration locus of viral DNA sequences. Array CGH was performed to analyse structural alterations of the cell genome. MCV DNA sequences were found in all ten cases of MCC and in none of the 1241 specimens of other tumour types. Clonal integration of MCV into the host genome was seen in all MCC cases and was checked by FISH in one case. A recurrent pattern of conserved viral sequences which encompassed the replication origin, the small tumour (ST), and the 5' part of the large tumour (LT) antigen DNA sequences was observed. Both ST and LT viral sequences were found to be significantly expressed in all MCCs. Neither recurrent site of integration nor alteration of cellular genes located near the viral sequences was observed. The tight association of MCV with MCC, the clonal pattern of MCV integration, and the expression of the viral oncoproteins strongly support a causative role for MCV in the tumour process. This information will help the development of novel approaches for the assessment and therapy of MCC and biologically related tumours.

244 citations


Journal ArticleDOI
TL;DR: The data indicate that frameshift mutations in ATG genes with mononucleotide repeats are common in gastric and colorectal carcinomas with MSI‐H, and suggest that these mutations may contribute to cancer development by deregulating the autophagy process.
Abstract: Mounting evidence indicates that alterations of autophagy processes are directly involved in the development of many human diseases, including cancers. Autophagy-related gene (ATG) products are main players in the autophagy process. In humans there are 16 known ATG genes, of which four (ATG2B, ATG5, ATG9B and ATG12) have mononucleotide repeats with seven or more nucleotides. Frameshift mutations of genes with mononucleotide repeats are features of cancers with microsatellite instability (MSI). It is not known whether ATG genes with mononucleotide repeats are altered by frameshift mutations in gastric and colorectal carcinomas with MSI. For this, we analysed the mononecleotide repeats in ATG2B, ATG5, ATG9B and ATG12 in 32 gastric carcinomas with high MSI (MSI-H), 13 gastric carcinomas with low MSI (MSI-L), 43 colorectal carcinomas with MSI-H and 15 colorectal carcinomas with MSI-L by a single-strand conformation polymorphism (SSCP) analysis. We found ATG2B, ATG5, ATG9B and ATG12 mutations in 10, 2, 13 and 0 cancers, respectively. The mutations were detected in MSI-H cancers but not in MSI-L cancers. Gastric and colorectal cancers with MSI-H harboured one or more ATG mutations in 28.1% and 27.9%, respectively. Our data indicate that frameshift mutations in ATG genes with mononucleotide repeats are common in gastric and colorectal carcinomas with MSI-H, and suggest that these mutations may contribute to cancer development by deregulating the autophagy process.

230 citations


Journal ArticleDOI
TL;DR: The activation of bipotential hepatic progenitor cells (HPCs) is clearly vital for survival in many cases of acute liver failure, and the signals that promote such reactions are being elucidated.
Abstract: The worldwide shortage of donor livers to transplant end stage liver disease patients has prompted the search for alternative cell therapies for intractable liver diseases, such as acute liver failure, cirrhosis and hepatocellular carcinoma (HCC). Under normal circumstances the liver undergoes a low rate of hepatocyte 'wear and tear' renewal, but can mount a brisk regenerative response to the acute loss of two-thirds or more of the parenchymal mass. A body of evidence favours placement of a stem cell niche in the periportal regions, although the identity of such stem cells in rodents and man is far from clear. In animal models of liver disease, adopting strategies to provide a selective advantage for transplanted hepatocytes has proved highly effective in repopulating recipient livers, but the poor success of today's hepatocyte transplants can be attributed to the lack of a clinically applicable procedure to force a similar repopulation of the human liver. The activation of bipotential hepatic progenitor cells (HPCs) is clearly vital for survival in many cases of acute liver failure, and the signals that promote such reactions are being elucidated. Bone marrow cells (BMCs) make, at best, a trivial contribution to hepatocyte replacement after damage, but other BMCs contribute to the hepatic collagen-producing cell population, resulting in fibrotic disease; paradoxically, BMC transplantation may help alleviate established fibrotic disease. HCC may have its origins in either hepatocytes or HPCs, and HCCs, like other solid tumours appear to be sustained by a minority population of cancer stem cells.

220 citations


Journal ArticleDOI
TL;DR: PTEN haploinsufficiency is common in hormone‐sensitive prostate cancer, though the incidence of genomic deletion and its downstream effects have not been elucidated in clinical samples of hormone refractory prostate cancer (HRPC).
Abstract: PTEN haploinsufficiency is common in hormone-sensitive prostate cancer, though the incidence of genomic deletion and its downstream effects have not been elucidated in clinical samples of hormone refractory prostate cancer (HRPC). Progression to androgen independence is pivotal in prostate cancer and mediated largely by the androgen receptor (AR). Since this process is distinct from metastatic progression, we examined alterations of the PTEN gene in locally advanced recurrent, non-metastatic human HRPC tissues. Retrospective analyses of PTEN deletion status were correlated with activated downstream phospho-Akt (p-Akt) pathway proteins and with the androgen receptor. The prevalence of PTEN genomic deletions in transurethral resection samples of 59 HRPC patients with known clinical outcome was assessed by four-colour FISH analyses. FISH was performed using six BAC clones spanning both flanking PTEN genomic regions and the PTEN gene locus, and a chromosome 10 centromeric probe. PTEN copy number was also evaluated in a subset of cases using single nucleotide polymorphism (SNP) arrays. In addition, the samples were immunostained with antibodies against p-Akt, p-mTOR, p-70S6, and AR. The PTEN gene was deleted in 77% of cases, with 25% showing homozygous deletions, 18% homozygous and hemizygous deletions, and 34% hemizygous deletions only. In a subset of the study group, SNP array analysis confirmed the FISH findings. PTEN genomic deletion was significantly correlated to the expression of downstream p-Akt (p < 0.0001), AR (p = 0.025), and to cancer-specific mortality (p = 0.039). PTEN deletion is common in HRPC, with bi-allelic loss correlating to disease-specific mortality and associated with Akt and AR deregulation.

217 citations


Journal ArticleDOI
TL;DR: The data indicate the occurrence of severe mitochondrial alterations in multiple sclerosis lesions, which coincides with enhanced mitochondrial oxidative stress, which support a mechanism whereby enhanced density of mitochondria in MS lesions might contribute to the formation of free radicals and subsequent tissue damage.
Abstract: Mitochondrial dysfunction has been implicated in the development and progression of multiple sclerosis (MS) lesions. Mitochondrial alterations might occur as a response to demyelination and inflammation, since demyelination leads to an increased energy demand in axons and could thereby affect the number, distribution and activity of mitochondria. We have studied the expression of mitochondrial proteins and mitochondrial enzyme activity in active demyelinating and chronic inactive MS lesions. Mitochondrial protein expression and enzyme activity in active and chronic inactive MS lesions was investigated using (immuno)histochemical and biochemical techniques. The number of mitochondria and their co-localization with axons and astrocytes within MS lesions and adjacent normal-appearing white matter (NAWM) was quantitatively assessed. In both active and inactive lesions we observed an increase in mitochondrial protein expression as well as a significant increase in the number of mitochondria. Mitochondrial density in axons and astrocytes was significantly enhanced in active lesions compared to adjacent NAWM, whereas a trend was observed in inactive lesions. Complex IV activity was strikingly up-regulated in MS lesions compared to control white matter and, to a lesser extent, NAWM. Finally, we demonstrated increased immunoreactivity of the mitochondrial stress protein mtHSP70 in MS lesions, particularly in astrocytes and axons. Our data indicate the occurrence of severe mitochondrial alterations in MS lesions, which coincides with enhanced mitochondrial oxidative stress. Together, these findings support a mechanism whereby enhanced density of mitochondria in MS lesions might contribute to the formation of free radicals and subsequent tissue damage.

Journal ArticleDOI
TL;DR: This work will first focus on the most well‐understood niches supporting the germline stem cells in the lower organisms Caenorhabditis elegans and Drosophila melanogaster before concentrating on the more complex, less well-understood mammalian niches support the neural, epidermal, haematopoietic and intestinal stem cells.
Abstract: Virtually every tissue of the adult organism maintains a population of putatively slowly-cycling stem cells that maintain homeostasis of the tissue and respond to injury when challenged. These cells are regulated and supported by the surrounding microenvironment, referred to as the stem cell ‘niche’. The niche includes all cellular and non-cellular components that interact in order to control the adult stem cell, and these interactions can often be broken down into one of two major mechanistic categories—physical contact and diffusible factors. The niche has been studied directly and indirectly in a number of adult stem cell systems. Herein, we will first focus on the most well-understood niches supporting the germline stem cells in the lower organisms Caenorhabditis elegans and Drosophila melanogaster before concentrating on the more complex, less well-understood mammalian niches supporting the neural, epidermal, haematopoietic and intestinal stem cells. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: P53 is regarded as a central player in tumour suppression, as it controls programmed cell death (apoptosis) as well as cellular senescence as mentioned in this paper, which acts as a barrier to tumourigenesis by imposing irreversible cell cycle arrest, and therapeutic strategies aimed at reactivation of p53 in tumours emerge as a promising approach for the treatment of cancer patients.
Abstract: p53 is regarded as a central player in tumour suppression, as it controls programmed cell death (apoptosis) as well as cellular senescence. While apoptosis eliminates cells at high risk for oncogenic transformation, senescence acts as a barrier to tumourigenesis by imposing irreversible cell cycle arrest. p53 can act directly or indirectly at multiple levels of the tumour suppression network by invoking a myriad of mechanisms. p53 induces the extrinsic and intrinsic apoptotic pathways at multiple steps to ensure an efficient death response. This response involves transcriptional activation or repression of target genes, as well as the recently identified microRNAs, and transcription-independent functions. Importantly, p53 loss of function is required for tumour maintenance. Therefore, therapeutic strategies aimed at reactivation of p53 in tumours emerge as a promising approach for the treatment of cancer patients.

Journal ArticleDOI
TL;DR: The observation that a significant, but not complete, reduction of VEGF in the retina does not cause detectable retinal degeneration suggests that appropriate doses of anti‐VEGF agents may be important to the safe treatment of retinal vascular diseases.
Abstract: Vascular endothelial growth factor (VEGF-A) is a major pathogenic factor and a therapeutic target for age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity. Despite intensive effort in the field, the cellular mechanisms of VEGF action remain virtually uninvestigated. This situation makes it difficult to design cellular target-based therapeutics for these diseases. In light of the recent finding that VEGF is a potential neurotrophic factor, revealing the cellular mechanisms of VEGF action becomes necessary to preserve its beneficial effect and inhibit its pathological function in long-term anti-VEGF therapeutics for ocular vascular diseases. We therefore generated conditional VEGF knockout mice with an inducible Cre/lox system and determined the significance of Muller cell-derived VEGF in retinal development and maintenance and ischaemia-induced neovascularizartion and vascular leakage. Retinal development in the conditional VEGF knockout mice was analysed by examining retinal and choroidal vasculatures and retinal morphology and function. Ischaemia-induced retinal neovascularization and vascular leakage in the conditional VEGF knockout mice were analysed with fluorescein angiography, quantification of proliferative neovascular cells, immunohistochemistry, and immunoblotting using an oxygen-induced retinopathy model. Our results demonstrated that disruption of Muller cell-derived VEGF resulted in no apparent defects in retinal and choroidal vasculatures and retinal morphology and function, significant inhibition of the ischaemia-induced retinal neovascularization and vascular leakage, and attenuation of the ischaemia-induced breakdown of the blood-retina barrier. These results suggest that the retinal Muller cell-derived VEGF is a major contributor to ischaemia-induced retinal vascular leakage and pre-retinal and intra-retinal neovascularization. The observation that a significant, but not complete, reduction of VEGF in the retina does not cause detectable retinal degeneration suggests that appropriate doses of anti-VEGF agents may be important to the safe treatment of retinal vascular diseases.

Journal ArticleDOI
TL;DR: The results suggest that true chromosome 17 polysomy is likely to be a rare event in breast cancer and that CEP17 copy number greater than 3.0 in FISH analysis is frequently related to gain or amplification of the centromeric region.
Abstract: Approximately 8% of breast cancers show increased copy numbers of chromosome 17 centromere (CEP17) by fluorescence in situ hybridization (FISH) (ie average CEP17 >3.0 per nucleus). Currently, this pattern is believed to represent polysomy of chromosome 17. HER2-amplified cancers have been shown to harbour complex patterns of genetic aberrations of chromosome 17, in particular involving its long arm. We hypothesized that aberrant copy numbers of CEP17 in FISH assays may not necessarily represent true chromosome 17 polysomy. Eighteen randomly selected CEP17 polysomic cases and a control group of ten CEP17 disomic cases, as defined by dual-colour FISH, were studied by microarray-based comparative genomic hybridization (aCGH), which was performed on microdissected samples using a 32K tiling-path bacterial artificial chromosome microarray platform. Additional FISH probes were employed for SMS (17p11.2) and RARA (17q21.2) genes, as references for chromosome 17 copy number. Microarray-based comparative genomic hybridization revealed that 11 out of the 18 polysomic cases harboured gains of 17q with involvement of the centromere, one displayed 17q gain sparing the centromeric region, and only one could be defined as polysomic. The remaining five cases displayed amplification of the centromeric region. Among these, one case, showing score 2+ by immunohistochemistry and 8.5 HER2 mean copy number, was classified as not amplified by HER2/CEP17 ratio and as amplified by HER2/SMS ratio. Our results suggest that true chromosome 17 polysomy is likely to be a rare event in breast cancer and that CEP17 copy number greater than 3.0 in FISH analysis is frequently related to gain or amplification of the centromeric region. Larger studies investigating the genetic profiles of CEP17 polysomic cases are warranted.

Journal ArticleDOI
TL;DR: Data confirm and extend previous observations that CTNNB1‐mutated tumours represent a distinct molecular subgroup of medulloblastomas with favourable outcome, indicating that therapy de‐escalation should be considered.
Abstract: Medulloblastoma is the most frequent malignant paediatric brain tumour. The activation of the Wnt/β-catenin pathway occurs in 10-15% of medulloblastomas and has been recently described as a marker for favourable patient outcome. We report a series of 72 paediatric medulloblastomas evaluated for β-catenin protein expression, CTNNB1 mutations, and comparative genomic hybridization. Gene expression profiles were also available in a subset of 40 cases. Immunostaining of β-catenin showed extensive nuclear staining (>50% of the tumour cells) in six cases and focal nuclear staining (<10% of cells) in three cases. The other cases either exhibited a signal strictly limited to the cytoplasm (58 cases) or were negative (five cases). CTNNB1 mutations were detected in all β-catenin extensively nucleopositive cases. The expression profiles of these cases documented strong activation of the Wnt/β-catenin pathway. Remarkably, five out of these six tumours showed a complete loss of chromosome 6. In contrast, cases with focal nuclear β-catenin staining, as well as tumours with negative or cytoplasmic staining, never demonstrated CTNNB1 mutation, Wnt/β-catenin pathway activation or chromosome 6 loss. Patients with extensive nuclear staining were significantly older at diagnosis and were in continuous complete remission after a mean follow-up of 75.7 months (range 27.5–121.2 months) from diagnosis. All three patients with focal nuclear staining of β-catenin died within 36 months from diagnosis. Altogether, these data confirm and extend previous observations that CTNNB1-mutated tumours represent a distinct molecular subgroup of medulloblastomas with favourable outcome, indicating that therapy de-escalation should be considered. International consensus on the definition criteria of this distinct medulloblastoma subgroup should be achieved. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: It is concluded that CD133 expression is a marker with high prognostic impact for colon cancer, while it seems to have no obvious functional role as a driving force of this malignancy.
Abstract: In colon cancer, CD133 has recently been used to enrich for a subset of tumour cells with tumour-initiating capabilities and was therefore suggested to mark colon cancer stem cells. However, this molecule has surprisingly been shown to lack functional importance for tumour initiation itself. Herein, we investigated whether CD133 may be relevant for colon cancer metastasis in patients, and as metastasis requires several additional biological characteristics besides tumour initiation, we examined the effects of knocking down CD133 expression in colon cancer cell lines on proliferation, migration, invasion, and colony formation. We demonstrate that high CD133 expression correlates strongly with synchronous liver metastasis in a matched case-control collection, while siRNA-mediated knock down of this factor has no significant effect on the mentioned biological characteristics. Thus, we conclude that CD133 expression is a marker with high prognostic impact for colon cancer, while it seems to have no obvious functional role as a driving force of this malignancy.

Journal ArticleDOI
TL;DR: Dysregulations of TGF‐β retention and Smad2 signalling in syndromic and non‐syndromic aneurysms of the ascending aorta are highlighted.
Abstract: Common features such as elastic fibre destruction, mucoid accumulation, and smooth muscle cell apoptosis are co-localized in aneurysms of the ascending aorta of various aetiologies. Recent experimental studies reported an activation of TGF-beta in aneurysms related to Marfan (and Loeys-Dietz) syndrome. Here we investigate TGF-beta signalling in normal and pathological human ascending aortic wall in syndromic and non-syndromic aneurysmal disease. Aneurysmal ascending aortic specimens, classified according to aetiology: syndromic MFS (n = 15, including two mutations in TGFBR2), associated with BAV (n = 15) or degenerative forms (n = 19), were examined. We show that the amounts of TGF-beta1 protein retained within and released by aneurysmal tissue were greater than for control aortic tissue, whatever the aetiology, contrasting with an unchanged TGF-beta1 mRNA level. The increase in stored TGF-beta1 was associated with enhanced LTBP-1 protein and mRNA levels. These dysregulations of the extracellular ligand are associated with higher phosphorylated Smad2 and Smad2 mRNA levels in the ascending aortic wall from all types of aneurysm. This activation correlated with the degree of elastic fibre fragmentation. Surprisingly, there was no consistent association between the nuclear location of pSmad2 and extracellular TGF-beta1 and LTBP-1 staining and between their respective mRNA expressions. In parallel, decorin was focally increased in aneurysmal media, whereas biglycan was globally decreased in aneurysmal aortas. In conclusion, this study highlights independent dysregulations of TGF-beta retention and Smad2 signalling in syndromic and non-syndromic aneurysms of the ascending aorta.

Journal ArticleDOI
TL;DR: More robust tests of ‘stemness’ are now being employed, using lineage‐specific genetic marking and tracking to show production of long‐lived clones and multipotentiality in vivo.
Abstract: While cultured embryonic stem (ES) cells can be harvested in abundance and appear to be the most versatile of cells for regenerative medicine, adult stem cells also hold promise, but the identity and subsequent isolation of these comparatively rare cells remains problematic in most tissues, perhaps with the notable exception of the bone marrow. The ability to continuously self-renew and produce the differentiated progeny of the tissue of their location are their defining properties. Identifying surface molecules (markers) that would aid in stem cell isolation is a major goal. Considerable overlap exists between different putative organ-specific stem cells in their repertoire of gene expression, often related to self-renewal, cell survival and cell adhesion. More robust tests of 'stemness' are now being employed, using lineage-specific genetic marking and tracking to show production of long-lived clones and multipotentiality in vivo. Moreover, the characterization of normal stem cells in specific tissues may provide a dividend for the treatment of cancer. The successful treatment of neoplastic disease may well require the specific targeting of neoplastic stem cells, cells that may well have many of the characteristics of their normal counterparts.

Journal ArticleDOI
TL;DR: This review gives a comprehensive overview on knowledge about localization and regulation of normal gastrointestinal stem cells and links it to the understanding of gastrointestinal tumourigenesis and malignant progression in the light of the cancer stem cell concept.
Abstract: An enormous body of knowledge about the biology of stem cells and their role in development, tissue homeostasis and cancer formation has been gained in the last 20 years. This review gives a comprehensive overview on knowledge about localization and regulation of normal gastrointestinal stem cells and links it to our understanding of gastrointestinal tumourigenesis and malignant progression in the light of the cancer stem cell concept. The focus is on intestinal stem cells and newly identified stem cell factors, such as the beta-catenin target gene Lgr5. The basis of intestinal stem cell regulation is a permanent crosstalk between epithelial and underlying mesenchymal cells in the intestinal stem cell niche. This crosstalk is mediated by crucial pathways, including the Wnt, Hedgehog (HH), Notch, PI3K and BMP pathways. Disturbances in this fine-regulated interaction can both initiate intestinal tumours and, in association with additional genetic alterations or environmental activation of embryonic processes such as epithelial-mesenchymal transition (EMT), lead to tumour invasion and metastasis.

Journal ArticleDOI
TL;DR: Assays used to detect mammary stem and progenitor cells, some of the properties of these cells and their progeny and how they relate to the cancer stem cells that drive breast tumour growth are focused on.
Abstract: Emerging evidence from a variety of tissue types, including the mammary gland, suggests that normal stem and progenitor cells are the likely targets for malignant transformation, and that these transformed cells can function as cancer stem cells that drive tumour growth. In order to develop therapies that target these cancer stem cells, it is essential to determine the molecular mechanisms that regulate the growth and differentiation of these cells and their normal counterparts. To this end, a number of quantitative robust clonal assays have been developed that can detect the presence of human and mouse mammary stem and progenitor cells. These assays, when used in conjunction with cell-sorting strategies, have permitted the prospective isolation and characterization of a variety of cell types, including stem cells. Evidence to date indicates that these stem cells exhibit properties of basal mammary cells, possess extensive self-renewal properties, and are capable of generating a large number of phenotypically-distinct progenitor cells, many of which display characteristics of luminal cells. This review article will focus on the assays used to detect mammary stem and progenitor cells, some of the properties of these cells and their progeny and how they relate to the cancer stem cells that drive breast tumour growth.

Journal ArticleDOI
TL;DR: Preclinical data suggest that the IGF system could be a promising target for therapy in these sarcomas, and the occasional occurrence of paraneoplastic hypoglycaemia as a result of the secretion of incompletely processed forms of pro‐IGF‐II by sarcoma is discussed.
Abstract: Sarcomas are a diverse group of malignant mesenchymal tumours arising from bone and soft tissues. The identification of critical cellular signalling pathways in sarcomas is an important issue for the development of new targeted therapies. This review highlights the experimental and clinical evidence supporting the role of the insulin-like growth factor (IGF) signalling system in the cellular transformation and progression of several types of sarcoma, including rhabdomyosarcoma, synovial sarcoma, leiomyosarcoma, Ewing's sarcoma and osteosarcoma. Preclinical data suggest that the IGF system could be a promising target for therapy in these sarcomas. Currently, therapies interrupting IGF signalling have been or are being developed. In recent phase 1 clinical studies with humanized monoclonal antibodies directed against IGF receptor type 1 (IGF-1R), objective tumour responses were observed in several patients with Ewing's sarcoma, encouraging further clinical testing in Ewing's sarcoma and other sarcoma (sub)types. Moreover, the occasional occurrence of paraneoplastic hypoglycaemia as a result of the secretion of incompletely processed forms of pro-IGF-II by sarcomas is discussed.

Journal ArticleDOI
TL;DR: Tissue slide‐based SELEX holds promise in identifying tumour markers and developing specific molecular probes for cancer diagnosis and also to reveal the molecular differences that are responsible for the diseases.
Abstract: We report a new in situ tissue slide-based SELEX strategy targeting neoplastic tissues from breast cancer patients. The methodology, using the molecular differences between clinical specimens, can evolve aptamers to all fractions of tissue. The aptamers may be used as new molecular probes for pathological diagnosis and tumour imaging, and also to reveal the molecular differences that are responsible for the diseases. The specific aptamers were enriched by unequal length strand PCR employing a structured (−) strand primer. After 12 rounds of selection, using the paraffin tissue sections from infiltrating ductal carcinomas as targets, and using the adjacent normal tissue from the same case as controls, one of the enriched ssDNA aptamers, BC15, was selected from a nucleic acid library and characterized as recognizing breast cancer cells either within the tissue sections or from the culture medium, but only weakly binding to adjacent normal cells or immortalized breast cell line MCF10A. The calculated equilibrium dissociation constants (Kd) of BC15 bound to MCF7 cells was 111.0 ± 36.9 nM. Through streptavidin magnetic beads mediated affinity purification assay followed by mass spectrometry identification and western blot confirmation, the target of BC15 was characterized to be hnRNP A1, which was further verified to be specifically and highly expressed in cancerous tissues of breast by hnRNP A1 antibody immunostaining as well as western blot. BC15 aptamer was also used to probe cancer cells in tissues from other pathological types of breast cancers including lobular carcinoma, ductal carcinoma complicated with lobular carcinoma, comedo carcinoma, and lymph node metastasis of breast ductal carcinoma origin or breast lobular carcinoma origin. Therefore, tissue slide-based SELEX holds promise in identifying tumour markers and developing specific molecular probes for cancer diagnosis. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: Results demonstrated not only that SATB2 is a potential novel prognostic factor for CRC, but also that selection of a highly metastatic clone of SW480 in vivo coupled with gene expression profiling is a powerful approach to identifying prognostic markers for CRC.
Abstract: To identify novel biomarkers of metastasis of colorectal cancer (CRC), we developed an orthotopic implantation model of murine CRC and selected in vivo M5, a subclone of the SW480 CRC cell line with enhanced potential for metastasis to the liver. We compared the differences in the gene expression profiles between M5 and SW480 cells using gene expression profiling. We found that expression of special AT-rich sequence-binding protein 2 (SATB2) was down-regulated in M5 cells. Immunohistochemical analysis of 146 colorectal tumour samples showed that underexpression of SATB2 was strongly correlated with poor prognosis, tumour invasion, lymph node metastasis, distant metastasis, and Dukes' classification for CRC. Univariate and multivariate survival analyses further showed that SATB2 expression was a potential favourable prognostic factor for CRC. These results demonstrated not only that SATB2 is a potential novel prognostic factor for CRC, but also that selection of a highly metastatic clone of SW480 in vivo coupled with gene expression profiling is a powerful approach to identifying prognostic markers for CRC.

Journal ArticleDOI
TL;DR: The identified genetic aberrations were not confined to MIFS; an identical t(1;10) was also found in a case of HFT and the amplicon in 3p was seen in an IMFH and the consequences of these alterations for gene expression were assessed.
Abstract: Myxoinflammatory fibroblastic sarcoma (MIFS) is a low-grade malignant neoplasm for which limited genetic information, including a t(1;10)(p22;q24) and amplification of chromosome 3 material, is available. To further characterize these aberrations, we have investigated eight soft tissue sarcomas diagnosed as MIFS, haemosiderotic fibrolipomatous tumour (HFT), myxoid spindle cell/pleomorphic sarcoma with MIFS features, and inflammatory malignant fibrous histiocytoma/undifferentiated pleomorphic sarcoma with prominent inflammation (IMFH) harbouring a t(1;10) or variants thereof and/or ring chromosomes with possible involvement of chromosome 3. Using chromosome banding, fluorescence in situ hybridization, array-based comparative genomic hybridization, global gene expression, and real-time quantitative PCR analyses, we identified the breakpoint regions on chromosomes 1 and 10, demonstrated and delineated the commonly amplified region on chromosome 3, and assessed the consequences of these alterations for gene expression. The breakpoints in the t(1;10) mapped to TGFBR3 in 1p22 and in or near MGEA5 in 10q24, resulting in transcriptional up-regulation of NPM3 and particularly FGF8, two consecutive genes located close to MGEA5. The ring chromosomes contained a commonly amplified 1.44 Mb region in 3p11-12, which was associated with increased expression of VGLL3 and CHMP2B. The identified genetic aberrations were not confined to MIFS; an identical t(1;10) was also found in a case of HFT and the amplicon in 3p was seen in an IMFH. Copyright (c) 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. (Less)

Journal ArticleDOI
TL;DR: This review surveys what the authors know of fusion genes in the carcinomas, summarizes the technical advances that now make it possible to search systematically for such genes, and concludes by putting fusion genes into the current picture of mutation in cancers.
Abstract: It has been known for 25 years that fusion genes play a central role in leukaemias and sarcomas but they have been neglected in the common carcinomas, largely because of technical limitations of cytogenetics. In the last few years it has emerged that gene fusions, caused by chromosome translocations, inversions, deletions, etc., are important in the common epithelial cancers, such as prostate and lung carcinoma. Most prostate cancers, for example, have an androgen-regulated fusion of one of the ETS transcription factor gene family. Early results of genome-wide searches for gene fusions in breast and other epithelial cancers suggest that most individual tumours will have several fused genes. Fusion genes are exceptionally powerful mutations. In their simplest form they can turn on expression by promoter insertion but they can also, for example, force dimerization of a protein or change its subcellular location. They are correspondingly important clinically, in classification and management and as targets for therapy. This review surveys what we know of fusion genes in the carcinomas, summarizes the technical advances that now make it possible to search systematically for such genes, and concludes by putting fusion genes into the current picture of mutation in cancers.

Journal ArticleDOI
TL;DR: Evaluated expression of AEG‐1 plays an important role in the aggressiveness of NSCLC, leading to a poor clinical outcome, and multivariate analysis suggested that A EG‐1 expression might be an independent prognostic indicator for the survival of NS CLC patients.
Abstract: Astrocyte elevated gene 1 (AEG-1), a novel oncoprotein, has been implicated in oncogenesis and cancer progression in various types of human cancers. The clinical significance and biological role of AEG-1 in non-small cell lung cancer (NSCLC), however, remain unclear. In the present study, we found that the expression of AEG-1 was markedly up-regulated in NSCLC cell lines and NSCLC tissues at the level of both transcription and translation. Ectopically expressed AEG-1 enhanced the migratory and invasive abilities of NSCLC cells, whereas knockdown of endogenous AEG-1 by specific shRNAs significantly inhibited these abilities. The function of AEG-1 on metastasis modulation was associated with the activation of the PI3K-Akt and NF-kappaB signalling pathways. Furthermore, we showed high expression of AEG-1 in 99/200 (49.5%) paraffin-embedded archival NSCLC specimens. Moreover, statistical analysis displayed a significant correlation in AEG-1 expression with the clinical stage (p < 0.001), T classification (p = 0.001), N classification (p = 0.015), distant metastasis (p = 0.004) and differentiation (p = 0.027). Patients with higher AEG-1 expression had an overall shorter survival time, whereas patients with lower expression of AEG-1 had a better survival time. Multivariate analysis suggested that AEG-1 expression might be an independent prognostic indicator for the survival of NSCLC patients. Taken together, our results suggest that elevated expression of AEG-1 plays an important role in the aggressiveness of NSCLC, leading to a poor clinical outcome.

Journal ArticleDOI
TL;DR: A novel heat‐induced antigen retrieval strategy using SDS‐containing Laemmli buffer for efficient intact protein recovery from formalin‐fixed tissues for subsequent analysis by western blotting is developed, and the protocol enables efficient extraction of non‐degraded, full‐length, immunoreactive protein.
Abstract: The development of efficient formaldehyde cross-link reversal strategies will make the vast diagnostic tissue archives of pathology departments amenable to prospective and retrospective translational research, particularly in biomarker-driven proteomic investigations. Heat-induced antigen retrieval strategies (HIARs) have achieved varying degrees of cross-link reversal, potentially enabling archival tissue usage for proteomic applications outside its current remit of immunohistochemistry (IHC). While most successes achieved so far have been based on retrieving tryptic peptide fragments using shot-gun proteomic approaches, attempts at extracting full-length, non-degraded, immunoreactive proteins from archival tissue have proved challenging. We have developed a novel heat-induced antigen retrieval strategy using SDS-containing Laemmli buffer for efficient intact protein recovery from formalin-fixed tissues for subsequent analysis by western blotting. Protocol optimization and comparison of extraction efficacies with frozen tissues and current leader methodology is presented. Quantitative validation of methodology was carried out in a cohort of matched tumour/normal, frozen/FFPE renal tissue samples from 10 patients, probed by western blotting for a selected panel of seven proteins known to be differentially expressed in renal cancer. Our data show that the protocol enables efficient extraction of non-degraded, full-length, immunoreactive protein, with tumour versus normal differential expression profiles for a majority of the panel of proteins tested being comparable to matched frozen tissue controls (rank correlation, r = 0.7292, p < 1.825e-09). However, the variability observed in extraction efficacies for some membrane proteins emphasizes the need for cautious interpretation of quantitative data from this subset of proteins. The method provides a viable, cost-effective quantitative option for the validation of potential biomarker panels through a range of clinical samples from existing diagnostic archives, provided that validation of the method is first carried out for the specific proteins under study.

Journal ArticleDOI
TL;DR: A20 deletion and gain at TNFA/B/C locus may play an important role in the development of translocation‐negative MALT lymphoma.
Abstract: The genetic basis of MALT lymphoma is largely unknown. Characteristic chromosomal translocations are frequently associated with gastric and pulmonary cases, but are rare at other sites. We compared the genetic profiles of 33 ocular adnexal and 25 pulmonary MALT lymphomas by 1 Mb array-comparative genomic hybridization (CGH) and revealed recurrent 6q23 losses and 6p21.2-6p22.1 gains exclusive to ocular cases. High-resolution chromosome 6 tile-path array-CGH identified NF-kappa B inhibitor A20 as the target of 6q23.3 deletion and TNFA/B/C locus as a putative target of 6p21.2-22.1 gain. Interphase fluorescence in situ hybridization showed that A20 deletion occurred in MALT lymphoma of the ocular adnexa (8/42 = 19%), salivary gland (2/24 = 8%), thyroid (1/9 = 11%) and liver (1/2), but not in the lung (26), stomach (45) and skin (13). Homozygous deletion was observed in three cases. A20 deletion and TNFA/B/C gain were significantly associated (P < 0.001) and exclusively found in cases without characteristic translocation. In ocular cases, A20 deletion was associated with concurrent involvement of different adnexal tissues or extraocular sites at diagnosis (p = 0.007), a higher proportion of relapse (67% versus 37%) and a shorter relapse-free survival (p = 0.033). A20 deletion and gain at TNFA/B/C locus may thus play an important role in the development of translocation-negative MALT lymphoma. Copyright (C) 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: A role for CNS‐draining lymph nodes in the induction of detrimental immune responses in EAE relapses is suggested, and it is conclusively demonstrated that the tolerance‐inducing capability of cervical lymph nodes is not involved in Eae.
Abstract: Despite lack of classical lymphatic vessels in the central nervous system (CNS), cells and antigens do reach the CNS-draining lymph nodes. These lymph nodes are specialized to mediate mucosal immune tolerance, but can also generate T- and B-cell immunity. Their role in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) therefore remains elusive. We hypothesized that drainage of CNS antigens to the CNS-draining lymph nodes is vital for the recurrent episodes of CNS inflammation. To test this, we surgically removed the superficial cervical lymph nodes, deep cervical lymph nodes, and the lumbar lymph nodes prior to disease induction in three mouse EAE models, representing acute, chronic, and chronic-relapsing EAE. Excision of the CNS-draining lymph nodes in chronic-relapsing EAE reduced and delayed the relapse burden and EAE pathology within the spinal cord, which suggests initiation of CNS antigen-specific immune responses within the CNS-draining lymph nodes. Indeed, superficial cervical lymph nodes from EAE-affected mice demonstrated proliferation against the immunizing peptide, and the deep cervical lymph nodes, lumbar lymph nodes, and spleen demonstrated additional proliferation against other myelin antigen epitopes. This indicates that intermolecular epitope spreading occurs and that CNS antigen-specific immune responses are differentially generated within the different CNS-draining lymphoid organs. Proliferation of splenocytes from lymphadenectomized and sham-operated mice against the immunizing peptide was similar. These data suggest a role for CNS-draining lymph nodes in the induction of detrimental immune responses in EAE relapses, and conclusively demonstrate that the tolerance-inducing capability of cervical lymph nodes is not involved in EAE.