Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q86TM3 (cage)
 29,987 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Increased mucosal expression of TF, the Thomsen-Friedenreich oncofetal blood group antigen (galactose beta1-3 N-acetylgalactosamine alpha-) occurs in colon cancer and colitis. This allows binding of TF-specific lectins, such as peanut agglutinin (PNA), which is mitogenic to the colorectal epithelium. To identify the cell surface TF-expressing glycoprotein(s), HT29 and Caco2 colon cancer cells were surface-labeled with Na[(125)I] and subjected to PNA-agarose affinity purification and electrophoresis. Proteins, approximately 110-180 kDa, present in HT29 but not Caco2 were identified by Western blotting as high molecular weight splice variants of CD44 (CD44v). Selective removal of TF antigen by Streptococcus pneumoniae endo-alpha-N-acetylgalactosaminidase substantially reduced PNA binding to CD44v. Immunoprecipitated CD44v from HT29 cell extracts also expressed sialyl-Tn (sialyl 2-6 N-acetylgalactosaminealpha-). Incubation of PNA 15 microg/ml with HT29 cells caused no additional proliferative effect in the presence of anti-CD44v6 mAb. In colon cancer tissue extracts (N = 3) PNA bound to CD44v but not to standard CD44. These data show that CD44v is a major PNA-binding glycoprotein in colon cancer cells. Because CD44 high molecular weight splice variants are present in colon cancer and inflammatory bowel disease tissue but are absent from normal mucosa, these results may also explain the increased PNA reactivity in colon cancer and inflammatory bowel disease. The coexpression of oncofetal carbohydrate antigens TF and sialyl-Tn on CD44 splice variants provides a link between cancer-associated changes in glycosylation and CD44 splicing, both of which correlate with increased metastatic potential.
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PMID:Cell surface-expressed Thomsen-Friedenreich antigen in colon cancer is predominantly carried on high molecular weight splice variants of CD44. 1144 38

Eukaryotic mRNAs are transcribed as precursors containing their intronic sequences. These are subsequently excised and the exons are spliced together to form mature mRNAs. This process can lead to transcript diversification through the phenomenon of alternative splicing. Alternative splicing can take the form of one or more skipped exons, variable position of intron splicing or intron retention. The effect of alternative splicing in expanding protein repertoire might partially underlie the apparent discrepancy between gene number and the complexity of higher eukaryotes. It is likely that more than 50% form. Many cancer-associated genes, such as CD44 and WT1 are alternatively spliced. Variation of the splicing process occurs during tumor progression and may play a major role in tumorigenesis. Furthermore, alternatively spliced transcripts may be extremely useful as cancer markers, since it appears likely that there may be striking contrasts in usage of alternatively spliced transcript variants between normal and tumor tissue than in alterations in the general levels of gene expression.
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PMID:Alternative spliced transcripts as cancer markers. 1167 53

Pre-mRNA processing is an important mechanism for globally modifying cellular protein composition during tumorigenesis. To understand this process during lung cancer, expression of two key pre-mRNA alternative splicing factors was compared in a mouse model of early lung carcinogenesis and during regenerative growth following reversible lung injury. Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and alternative splicing factor/splicing factor 2 (ASF/SF2) act antagonistically to modulate splice site selection. Both hnRNP A1 and ASF/SF2 contents rose in adenomas and during injury-induced hyperplasia compared to control lungs, as measured by immunoblotting. While both proteins increased similarly during compensatory hyperplasia, hnRNP A1 increased to a much greater extent than ASF/SF2 in tumors, resulting in a 6-fold increase of the hnRNP A1 to ASF/SF2 ratio. Immunohistochemical analysis showed that hnRNP A1 localized exclusively within tumor nuclei, while ASF/SF2 appeared in cytoplasm and/or nuclei, depending on the growth pattern of the tumor cells. We also demonstrated cancer-associated changes in the pre-mRNA alternative splicing of CD44, a membrane glycoprotein involved in cell-cell and cell-extracellular matrix interactions. hnRNP A1 and ASF/SF2 expression is thus differentially altered in neoplastic lung cells by mechanisms that do not strictly arise from increased cell division. These changes are influenced by tumor histology and may be associated with production of variant CD44 mRNA isoforms.
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PMID:Relative amounts of antagonistic splicing factors, hnRNP A1 and ASF/SF2, change during neoplastic lung growth: implications for pre-mRNA processing. 1539 79

Hepatic metastasis is a primary cause for failure of locoregional therapy in colorectal cancer. Increased expression of osteopontin (OPN), a ligand for alpha(v)beta3 integrin and CD44 receptors, is associated with metastasis in several types of cancer. However, the mechanism by which OPN mediates metastasis in colorectal cancer remains unknown. We hypothesized that OPN mediates invasion of colon cancer cells through basement membrane and migration through extracellular matrix (ECM). In this study, we used CT26 murine colon adenocarcinoma cells syngeneic to BALB/c mice to generate cell lines (pS-OPN) in which OPN expression was suppressed through small interfering RNA (siRNA) plasmids. CT26 wild-type cells (WT) and CT26 cells stably expressing murine-mismatch siRNA (pS-MM) served as controls. Western blotting quantified OPN protein levels and our most downregulated clone, pS-OPN-A4, demonstrated a mean 3.0-fold decrease in OPN protein expression versus WT. In vitro cell motility and invasiveness were decreased in pS-OPN-A4 by 3.6-fold (P = 0.004 versus WT) and 4.1-fold (P = 0.01 versus WT), but proliferation was similar amongst cell lines. We demonstrated that OPN suppression significantly correlates with MMP-2 downregulation. In vivo hepatic metastasis was assessed by quantifying liver weights and surface tumor nodules in 33 BALB/c mice (11/group) subjected to intrasplenic injection of tumor cells. pS-OPN-A4 resulted in a 50.4% decrease in mean liver weight compared with WT (3.79 +/- 1.49 g versus 1.88 +/- 1.34 g, P = 0.009). Only 18% of pS-OPN-A4 livers had >20 metastatic surface nodules compared with 89% for WT and 75% for pS-MM-V6. This study demonstrates that RNA interference stably reduces CT26 tumor expression of OPN and significantly attenuates CT26 colon cancer metastasis by diminishing tumor cell motility and invasiveness.
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PMID:Osteopontin silencing by small interfering RNA suppresses in vitro and in vivo CT26 murine colon adenocarcinoma metastasis. 1566 2

Some markers of angiogenic endothelial cells are emerging as targets of cancer therapy. The present study compares the expression of CD105 with that of other endothelial markers in all tissue layers during the development of colon cancer. We immunohistochemically analyzed the expression of the colon adenoma-carcinoma sequence by endothelial cells using a panel of eight endothelial markers. We examined sections from endoscopic mucosal resection and surgical resection of tubular adenoma (n=31), carcinoma in adenoma (n=11), and adenocarcinoma (n=34). Cylindrical cores were punched out from donor paraffin blocks of normal mucosa adjacent to tumors, from tumor lesions of mucosa, submucosa, muscularis propria, subserosa, and serosa, and from lymph node metastases. CD31 (PECAM-1) was universally expressed in the blood vessels of adenoma-carcinoma lesions as well as in normal mucosal vessels (80-95%), with no significant differences. In contrast, cancer-associated blood vessels (up to 80%) and cancer cells themselves expressed high levels of CD105. In normal mucosa, CD105 was weakly expressed in endothelial cells of capillaries (< or =21%), and significant differences in its expression in endothelial cells between the normal mucosa and adenoma, carcinoma in adenoma, and adenocarcinoma were found. Flt-1, Flk-1, transforming growth factor-beta1, transforming growth factor-beta receptor II, and CD44 were strongly expressed in the cancer cells but were not expressed in the blood vessels. Vascular endothelial growth factor was expressed at <30% in the blood vessels of adenoma, carcinoma in adenoma, and carcinoma. Moreover, this study provided evidence that CD105 was expressed exclusively in endothelial blood vessels by double immunostaining of CD105 and D2-40. The present study shows that de novo blood vessels of colon cancer specifically express CD105. These findings provide the basis for novel antiangiogenic cancer therapies.
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PMID:Endoglin (CD105) expression in angiogenesis of colon cancer: analysis using tissue microarrays and comparison with other endothelial markers. 1617 81

There is significant evidence supporting the hypotheses that lifestyle, diet, and bioactive components in foods are important modifiers of cancer risk. However, our ability to assess host response noninvasively is limited. To overcome this, we have developed a technology to isolate several million viable exfoliated somatic colonic cells from a small sample of stool (0.5-1.0 g) by a procedure known as somatic cell sampling and recovery (SCSR). Orally administered carotenoids appear in these cells several days after consuming the supplement, usually showing a peak concentration between 5-7 d after their ingestion. The time lag observed for the appearance of orally administered carotenoids in SCSR cells corresponds to the turnover rate of the colonic mucosa. This is an example of how changes in cell turnover rates can be carefully assessed using the SCSR system. The specific mechanisms by which individual constituents of diet affect the cancer process are not fully understood. However, host response to dietary constituents may be investigated, noninvasively, by following the modulation of tumor-associated molecular markers in these exfoliated SCSR cells. We have demonstrated the feasibility of using SCSR cells to detect the expression of carcinoembryonic antigen, CD44, and its splice variants, c-myc, c-erbb2, and mutations in the p53 gene. In this regard, SCSR cells are a readily available surrogate cellular target that may serve to monitor changes in cell turnover, differentiation, and expression of cancer-associated biomarkers that are likely to be modulated by bioactive food components.
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PMID:Exfoliated colonic epithelial cells: surrogate targets for evaluation of bioactive food components in cancer prevention. 1625 37

Interaction of nuclear beta-catenin and TCF4 is the end point of canonical Wnt signaling, which is believed to trigger the transcription of multiple cancer-associated genes, including CD44. So far, the combined status of beta-catenin and TCF4 and its relevance for lymph node metastasis and CD44 expression have not been well studied in gastric cancers (GCs). To address these issues, we examined 31 GCs, 17 premalignant tissues, 10 noncancerous gastric mucosae, 17 regional lymph node metastases, and 4 human GC cell lines (MGC803, MGC823, AGS, and HGC-27) using immunohistochemical and immunofluorescence staining, reverse transcriptase polymerase chain reaction, and Western blot analysis. Frequent TCF4 up-regulation and nuclear translocation of beta-catenin were found in both primary and metastatic tumors. Standard CD44 was detected in all gastric tissue samples. The frequency of variant CD44 expression increased in parallel with stepwise gastrocarcinogenesis and tumor spread, but the rates of detection did not match that of nuclear beta-catenin and TCF4, especially in the premalignant and noncancerous samples. The data from the 4 cell lines were in accordance with the in vivo findings in terms of beta-catenin nuclear translocation, TCF4 activation, and CD44 expression. Our results suggest an established Wnt signaling pathway in most GCs, a close correlation of beta-catenin/TCF4-mediated signaling with tumor dissemination, and the unlikelihood of a direct effect of activated Wnt signaling on CD44 expression. The influence of beta-catenin-TCF4 interaction on alternative CD44 splicing was not established. These 3 alterations may be regarded as unfavorable features of GC.
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PMID:Nuclear translocations of beta-catenin and TCF4 in gastric cancers correlate with lymph node metastasis but probably not with CD44 expression. 1631 Nov 23

We provide here an example of clinical application of functional glycoproteomics for cancer diagnosis. Sialyl Lewis a and sialyl Lewis x glycotopes, which are the specific ligands for selectins, and variant forms of CD44, which are the adhesion molecules recognizing hyaluronate, are both implicated in cancer metastasis. The CD44 variants modified by the sialyl Lewis a and sialyl Lewis x glycotopes are expected to have dual functions, serving as ligands for vascular selectins, and simultaneously having binding activity to vascular bed hyaluronate, and are expected to figure heavily in cancer metastasis. We developed a heterogeneous sandwich assay system to detect soluble CD44v specifically modified by the cancer-associated sialyl Lewis a/x glycotopes, using the extracellular domain of CD44v cleaved by the metalloproteinase ADAM10 as standard molecules. We also developed the assay system for CD44v modified by normal epithelial glycotopes including disialyl Lewis a and sialyl 6-sulfo Lewis x. The results indicated that serum levels of soluble CD44v modified by cancer-associated glycotopes were frequently increased in patients with cancers, while those of CD44v modified by the nonmalignant glycotopes tended to be elevated in patients with benign disorders.
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PMID:Clinical application of functional glycoproteomics - dissection of glycotopes carried by soluble CD44 variants in sera of patients with cancers. 1869 Jun 45

WNT5A is a cancer-associated gene involved in invasion and metastasis of melanoma, breast cancer, pancreatic cancer, and gastric cancer. WNT5A transduces signals through Frizzled, ROR1, ROR2 or RYK receptors to beta-catenin-TCF/LEF, DVL-RhoA-ROCK, DVL-RhoB-Rab4, DVL-Rac-JNK, DVL-aPKC, Calcineurin-NFAT, MAP3K7-NLK, MAP3K7-NF-kappaB, and DAG-PKC signaling cascades in a context-dependent manner. SNAI1 (Snail), CD44, G3BP2, and YAP1 are WNT5A target genes. We and other groups previously reported that IL6- or LIF-induced signaling through JAK-STAT3 signaling cascade is involved in WNT5A upregulation (STAT3-WNT5A signaling loop). Here, refined integrative genomic analyses of WNT5A were carried out to elucidate other mechanisms of WNT5A transcription. The WNT5A gene was found to encode two isoforms by using alternative first exons 1A and 1B. Quadruple Smad-binding elements (SBEs), single Sp1-binding site (GC-box), PPARgamma-binding site, C/EBP-binding site and bHLH-binding site within the promoter A region, 5'-adjacent to exon 1A, were conserved in human WNT5A, chimpanzee WNT5A, mouse Wnt5a, and rat Wnt5a. NF-kappaB-binding site, CUX1-binding site, double SBEs and double GC-boxes within the promoter B region, 5'-adjacent to exon 1B, were conserved in mammalian WNT5A orthologs. Quadruple FOX-binding sites and double SBEs within ultra-conserved intron 1 were also conserved in mammalian WNT5A orthologs. Conserved NF-kappaB-binding site within the WNT5A promoter B region elucidated the mechanisms that TNFalpha and toll-like receptor (TLR) signals upregulate WNT5A via MAP3K7. Quadruple FOX-binding sites rather than GLI-binding site revealed that Hedgehog signals induce WNT5A upregulation indirectly via FOX family members, such as FOXA2, FOXC2, FOXE1, FOXF1 and FOXL1. TGFbeta signals were found to upregulate WNT5A expression directly through the Smad complex, and also indirectly through Smad-induced CUX1 and MAP3K7-mediated NF-kappaB. Together these facts indicate that WNT5A is transcribed based on multiple mechanisms, such as NF-kappaB, Hedgehog, TGFbeta, and Notch signaling cascades.
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PMID:Transcriptional mechanisms of WNT5A based on NF-kappaB, Hedgehog, TGFbeta, and Notch signaling cascades. 1942 2

Adhesion of circulating tumor cells to the blood vessel endothelium is a critical step in cancer metastasis. We show in this study that galectin-3, the concentration of which is greatly increased in the circulation of cancer patients, increases cancer cell adhesion to macrovascular and microvascular endothelial cells under static and flow conditions, increases transendothelial invasion, and decreases the latency of experimental metastasis in athymic mice. These effects of galectin-3 are shown to be a consequence of its interaction with cancer-associated MUC1, which breaks the "protective shield" of the cell-surface MUC1 by causing MUC1 polarization, leading to exposure of smaller cell-surface adhesion molecules/ligands including CD44 and ligand(s) for E-selectin. Thus, the interaction in the bloodstream of cancer patients between circulating galectin-3 and cancer cells expressing MUC1 bearing the galectin-3 ligand TF (Galbeta1,3GalNAc-) promotes metastasis. This provides insight into the molecular regulation of metastasis and has important implications for the development of novel therapeutic strategies for prevention of metastasis.
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PMID:Circulating galectin-3 promotes metastasis by modifying MUC1 localization on cancer cell surface. 1969 Jan 36


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