CD133 expression predicts for non-response to chemotherapy in colorectal cancer

The cancer stem cell hypothesis may explain why conventional chemotherapies are unable to fully eradicate cancers. In this study, we examined both the prognostic and predictive significance of putative cancer stem cell markers in colorectal cancer. In this study, immunohistochemistry for three candidate cancer stem cell markers (CD133, Oct-4 and Sox-2) and for six other postulated prognostic markers (CK7, CK20, Cox-2, Ki-67, p27 and p53) were performed using tissue microarrays containing 501 primary colorectal cancer cases. Receiver-operating characteristic analysis was used to determine cut-off scores for positive protein expression. Multivariate analysis revealed that positive expression for CD133 and Oct-4 was associated with significantly worse survival in patients treated by surgery alone (P=0.023 and P

Cofilin immunolabelling correlates with depth of invasion in gastrointestinal endocrine cell tumors

Gastrointestinal endocrine cell tumors are a heterogeneous population of lesions believed to arise from neuroendocrine cells of the gastrointestinal mucosa. The current classification of these tumors is based on tumor size, microscopic features and clinical evidence of metastasis. Although diagnostic categories generally correlate with prognosis, molecular prognostic markers will be clinically useful adjuncts. Cofilin has been implicated in tumor invasion, and its immunolocalisation was studied in gastrointestinal endocrine cell tumors. The immunolocalisation of cofilin was studied by immunohistochemistry in 34 formalin-fixed, paraffin wax-embedded gastrointestinal endocrine cell tumors using a tissue microarray platform. A significant correlation was found between high cofilin immunolabelling and the depth of invasion (p

Claudin-1 Has Tumor Suppressive Activity and Is a Direct Target of RUNX3 in Gastric Epithelial Cells

BACKGROUND & AIMS: The transcription Factor RUNX3 is a gastric tumor suppressor. Tumorigenic Runx3(-/-) gastric epithelial cells attach weakly to each other, compared with nontumorigenic Runx3(+/+) cells. We alined to identify RUNX3 target genes that promote cell-cell contact to Improve our understanding of RUNX3's role in Suppressing gastric carcinogenesis. METHODS: We compared gene expression profiles of Runx3(+/+) and Runx3(-/-) cells and observed down-regulation of genes associated with cell-cell adhesion in Runx3(-/-) cells. Reporter, mobility shift, and chromatin immunoprecipitation assays were used to examine the regulation of these genes by RUNX3. Tumorigenesis assays and immunohistologic, analyses of human gastric tumors were performed to confirm the role of the candidate genes ill gastric tumor development. RESULTS: Mobility shift and chromatin immunoprecipitation assays revealed that the promoter activity of the gene that encodes the tight Junction protein claudin-1 was up-regulated via the binding of RUNX3 to the RUNX consensus sites. The tumorigenicity of gastric epithelial cells From Runx3(-/-) mice was significantly reduced by restoration of claudin-1 expression, whereas knockdown of claudin-1. increased the tumorigenicity of human gastric cancer cells. Concomitant expression of RUNX3 and claudin-1 was observed in human normal gastric epithelium and cancers. CONCLUSIONS: The tight junction protein claudin-1 has gastric tumor suppressive activity and is a direct transcriptional target of RUNX3. Claudin-1 is down-regulated during the epithelial-mesenchymal transition; RUNX3 might therefore act as a tumor suppressor to antagonize the epithelial-mesenchymal transition.

PIM-1 kinase expression in adipocytic neoplasms: diagnostic and biological implications

The differential diagnosis of soft tissue tumours poses a considerable challenge for pathologists, especially adipocytic tumours, as these may show considerable overlap in clinical presentation and morphological features with many other mesenchymal neoplasms. Hence, a specific and reliable marker that identifies adipocytic differentiation is much sought. We investigated the immunohistochemical expression of PIM-1 kinase in 35 samples of soft tissue tumours using tissue microarray technology and 49 full sections of adipocytic (n = 26) and non-adipocytic tumours (n = 23). Benign and malignant adipocytic tumours showed strong expression of PIM-1 while the non-adipocytic tumours were either negative or showed only weak staining for the protein. In myxoid liposarcomas, PIM-1 showed a distinct, unique vacuolar staining pattern, clearly outlining fine cytoplasmic lipid vacuoles. By contrast, non-adipocytic myxoid tumours (myxoma, chordoma and myxoid chondrosarcoma) did not show this vacuolar pattern of PIM-1 staining, although vacuolated cells were present on H&E. This differential expression was confirmed at a gene expression level in selected cases. Our results indicate that the expression of PIM-1 in adipose tissue may be a useful marker of adipocytic differentiation, in particular if the staining is both of high intensity and present in a unique, vacuolar pattern.

A Multicenter Blinded Study to Evaluate KRAS Mutation Testing Methodologies in the Clinical Setting

Evidence that activating mutations of the KRAS oncogene abolish the response to anti-epidermal growth factor receptor therapy has revolutionized the treatment of advanced colorectal cancer. This has resulted in the urgent demand for KRAS mutation testing in the clinical setting to aid choice of therapy. The Am of this study was to evaluate six different KRAS mutation detection methodologies on two series of primary colorectal cancer samples. Two series of 80 frozen and 74 formalin-fixed paraffin-embedded tissue samples were sourced and DNA was extracted at a central site before distribution to seven different testing sites. KRAS mutations in codons 12 and 13 were assessed by using single strand conformation polymorphism analysis, pyrosequencing, high resolution melting analysis, dideoxy sequencing, or the commercially available TIB Molbiol (Berlin, Germany) or DxS Diagnostic innovations (Manchester, UK) kits. in frozen tissue samples, concordance in KRAS status (defined as consensus in at least five assays) was observed in 66/80 (83%) cases. In par-affin tissue, concordance was 46/74 (63%) if all assays were considered or 71/74 (96%) using the five best performing assays. These results demonstrate that a variety of detection methodologies are suitable and provide comparable results for KRAS mutation analysis of clinical samples. (J Mol Diagn 2009, 11:543-552; DOI: 10.2353/jmoldx.2009.090057)

Repression of NHE1 Expression by PPAR gamma Activation Is a Potential New Approach for Specific Inhibition of the Growth of Tumor Cells In vitro and In vivo

Ligand-induced activation of peroxisome proliferator-activated receptor gamma (PPAIR gamma) inhibits proliferation in cancer cells in vitro and in vivo; however, the downstream targets remain undefined. We report the identification of a peroxisome proliferator response element in the promoter region of the Na+/ H transporter gene NHE1, the overexpression of which has been associated with carcinogenesis. Exposure of breast cancer cells expressing high levels of PPAR gamma to its natural and synthetic agonists resulted in downregulation of NHE1 transcription as well as protein expression. Furthermore, the inhibitory effect of activated PPAR gamma on tumor colony-forming ability was abrogated on overexpression of NHE1, whereas small interfering RNA-mediated gene silencing of NHE1 significantly increased the sensitivity of cancer cells to growth-inhibitory stimuli. Finally, histopathologic analysis of breast cancer biopsies obtained from patients with type II diabetes treated with the synthetic agonist rosiglitazone showed significant repression of NHE1 in the tumor tissue. These data provide evidence for tumor-selective downregulation of NHE1 by activated PPAR gamma in vitro and in pathologic specimens from breast cancer patients and could have potential implications for the judicious use of low doses of PPAR gamma ligands in combination chemotherapy regimens for an effective therapeutic response. [Cancer Res 2009;69(22):8636-44]

Runx2, p53, and pRB Status as Diagnostic Parameters for Deregulation of Osteoblast Growth and Differentiation in a New Pre-Chemotherapeutic Osteosarcoma Cell Line (OS1)

Osteosarcomas are the most prevalent primary bone tumors found in pediatric patients. To understand their molecular etiology, cell culture models are used to define disease mechanisms under controlled conditions. Many osteosarcoma cell lines (e.g., SAOS-2, U2OS, MG63) are derived from Caucasian patients. However, patients exhibit individual and ethnic differences in their responsiveness to irradiation and chemotherapy. This motivated the establishment of osteosarcoma cell lines (OS1, OS2, OS3) from three ethnically Chinese patients. OS1 cells, derived from a pre-chemotherapeutic tumor in the femur of a 6-year-old female, were examined for molecular markers characteristic for osteoblasts, stem cells, and cell cycle control by immunohistochemistry, reverse transcriptase-PCR, Western blotting and flow cytometry. OS I have aberrant G-banded karyotypes, possibly reflecting chromosomal abnormalities related to p53 deficiency. OS I had ossification profiles similar to human fetal osteoblasts rather than SAOS-2 which ossifies ab initio, (P

Overexpression of endoplasmic reticulum protein 29 regulates mesenchymal-epithelial transition and suppresses xenograft tumor growth of invasive breast cancer cells

Endoplasmic reticulum protein 29 (ERp29) is a novel endoplasmic reticulum ( ER) secretion factor that facilitates the transport of secretory proteins in the early secretory pathway. Recently, it was found to be overexpressed in several cancers; however, little is known regarding its function in breast cancer progression. In this study, we show that the expression of ERp29 was reduced with tumor progression in clinical specimens of breast cancer, and that overexpression of ERp29 resulted in G(0)/G(1) arrest and inhibited cell proliferation in MDA-MB-231 cells. Importantly, overexpression of ERp29 in MDA-MB-231 cells led to a phenotypic change and mesenchymal-epithelial transition (MET) characterized by cytoskeletal reorganization with loss of stress fibers, reduction of fibronectin (FN), reactivation of epithelial cell marker E-cadherin and loss of mesenchymal cell marker vimentin. Knockdown of ERp29 by shRNA in MCF-7 cells reduced E-cadherin, but increased vimentin expression. Furthermore, ERp29 overexpression in MDA-MB-231 and SKBr3 cells decreased cell migration/invasion and reduced cell transformation, whereas silencing of ERp29 in MCF-7 cells enhanced cell aggressive behavior. Significantly, expression of ERp29 in MDA-MB-231 cells suppressed tumor formation in nude mice by repressing the cell proliferative index (Ki-67 positivity). Transcriptional profiling analysis showed that ERp29 acts as a central regulator by upregulating a group of genes with tumor suppressive function, for example, E-cadherin (CDH1), cyclin-dependent kinase inhibitor (CDKN2B) and spleen tyrosine kinase (SYK), and by downregulating a group of genes that regulate cell proliferation (eg, FN, epidermal growth factor receptor ( EGFR) and plasminogen activator receptor ( uPAR)). It is noteworthy that ERp29 significantly attenuated the overall ERK cascade, whereas the ratio of p-ERK1 to p-ERK2 was highly increased. Taken together, our results showed that ERp29 is a novel regulator leading to cell growth arrest and cell transition from a proliferative to a quiescent state, and reprogramming molecular portraits to suppress the tumor growth of MDA-MB-231 breast cancer cells. Laboratory Investigation (2009) 89, 1229-1242; doi: 10.1038/labinvest.2009.87; published online 21 September 2009

Elucidating the molecular physiopathology of acute respiratory distress syndrome in severe acute respiratory syndrome patients

Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury. It is a response to various diseases of variable etiology, including SARS-CoV infection. To date, a comprehensive study of the genomic physiopathology of ARDS (and SARS) is lacking, primarily due to the difficulty of finding suitable materials to study the disease process at a tissue level (instead of blood, sputa or swaps). Hereby we attempt to provide such study by analyzing autopsy lung samples from patient who died of SARS and showed different degrees of severity of the pulmonary involvement. We performed real-time quantitative PCR analysis of 107 genes with functional roles in inflammation, coagulation, fibrosis and apoptosis: some key genes were confirmed at a protein expression level by immunohistochemistry and correlated to the degree of morphological severity present in the individual samples analyzed. Significant expression levels were identified for ANPEP (a receptor for CoV), as well as inhibition of the STAT1 pathway, IFNs production and CXCL10 (a T-cell recruiter). Other genes unassociated to date with ARDS/SARS include C1Qb, C5R1, CASP3, CASP9, CD14, CD68, FGF7, HLA-DRA, ICF1, IRF3, MALAT-1, MSR1, NFIL3, SLPI, USP33, CLC, GBP1 and TACI. As a result, we proposed to therapeutically target some of these genes with compounds such as ANPEP inhibitors, SLPI and dexamethasone. Ultimately, this study may serve as a model for future, tissue-based analyses of fibroinflammatory conditions affecting the lung. (C) 2009 Elsevier B.V. All rights reserved.

Genetic factors associated with intestinal metaplasia in a high risk Singapore-Chinese population: a cohort study

Background: Intestinal metaplasia (IM) is an important precursor lesion in the development of gastric cancer ( GC). The aim of this study was to investigate genetic factors previously linked to GC risk for their possible association with IM. A total of 18 polymorphisms in 14 candidate genes were evaluated in a Singapore-Chinese population at high risk of developing GC.

Molecular pathology of RUNX3 in human carcinogenesis

A major goal of molecular biology is to elucidate the mechanisms underlying cancer development and progression in order to achieve early detection, better diagnosis and staging and novel preventive and therapeutic strategies. We feel that an understanding of Runt-related transcription factor 3 (RUNX3)-regulated biological pathways will directly impact our knowledge of these areas of human carcinogenesis. The RUNX3 transcription factor is a downstream effector of the transforming growth factor-beta (TGF-beta) signaling pathway, and has a critical role in the regulation of cell proliferation and cell death by apoptosis, and in angiogenesis, cell adhesion and invasion. We previously identified RUNX3 as a major gastric tumor suppressor by establishing a causal relationship between loss of function and gastric carcinogenesis. More recently, we showed that RUNX3 functions as a bona fide initiator of colonic carcinogenesis by linking the Wnt oncogenic and TGF-beta tumor suppressive pathways. Apart from gastric and colorectal cancers. a multitude of epithelial cancers exhibit inactivation of RUNX3, thereby making it a putative tumor suppressor in human neoplasia. This review highlights our current understanding of the molecular mechanisms of RUNX3 inactivation in the context of cancer development and progression. (C) 2009 Elsevier B.V. All rights reserved.

Positive association between nuclear Runx2 and oestrogen-progesterone receptor gene expression characterises a biological subtype of breast cancer

Purpose: The runt-related transcription factor, Runx2 may have an oncogenic role in mediating metastatic events in breast cancer, but whether Runx2 has a role in the early phases of breast cancer development is not clear. We examined the expression of Runx2 and its relationship with oestrogen receptor (ER) and progesterone receptor (PR) in breast cancer cell lines and tissues.

Recurrent lower gastrointestinal bleeding secondary to cytomegalovirus-associated colonic ulcer in a non human immunodeficiency virus infected patient:Timely diagnosis and treatment averted surgery

Mr C, a 68-year-old Chinese male with diabetes mellitus, previous stroke and ischaemic cardiomyopathy on clopidogrel, presented with haematochezia. Colonoscopy showed a sigmoid ulcer, which was treated endoscopically. Histology of the biopsy from the ulcer revealed non-specific changes. However, he presented with recurrent bleeding from this non-healing sigmoid ulcer. A review of the histologic specimen revealed CMV intranuclear inclusion bodies. He was treated with intravenous ganciclovir, with no further hematochezia.

Keywords Hematochezia, cytomegalovirus, ulcer