Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic alterations of WNT signaling molecules lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway. We have previously cloned and characterized WNT2B/WNT13 gene on human chromosome 1p13, which is homologous to proto-oncogene WNT2 on human chromosome 7q31. WNT2B1 and WNT2B2 mRNAs, generated from the WNT2B gene due to alternative splicing of the alternative promoter type, encode almost identical polypeptides with divergence in the N-terminal region. WNT2B2 mRNA rather than WNT2B1 mRNA is preferentially expressed in NT2 cells with the potential of neuronal differentiation. Here, we describe our investigations of expression of WNT2B mRNAs in various types of human primary cancer. Matched tumor/normal expression array analysis revealed that WNT2B mRNAs were significantly up-regulated in 2 of 8 cases of primary gastric cancer. WNT2B2 mRNA rather than WNT2B1 mRNA was found to be preferentially up-regulated in a case of primary gastric cancer (signet ring cell carcinoma). Function of WNT2B1 mRNA and that of WNT2B2 mRNA were investigated by using Xenopus axis duplication assay. Injection of synthetic WNT2B1 mRNA into the ventral marginal zone of fertilized Xenopus eggs at the 4-cell stage did not induce axis duplication. In contrast, ventral injection of synthetic WNT2B2 mRNA induced axis duplication in 90% of embryos (complete axis duplication, 24%). These results strongly suggest that WNT2B2 up-regulation in some cases of gastric cancer might lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway.
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PMID:WNT2B2 mRNA, up-regulated in primary gastric cancer, is a positive regulator of the WNT- beta-catenin-TCF signaling pathway. 1174 4

Beta-catenin is critical for intercellular adhesion and also plays a role as a transcription activating protein in the Wnt signalling pathway. Increased protein levels and mutation of the beta-catenin gene have been demonstrated in various cancers; however, the role of beta-catenin in gastric cancer remains largely unknown. Using gastric cancer tissues and normal adjacent gastric mucosa obtained from 20 patients with gastric cancer (eight diffuse-type, 12 intestinal-type) undergoing gastric resection or endoscopy, we assessed the expression of beta-catenin by immunohistochemistry and quantitative PCR analysis. Furthermore, the tumour suppressor gene APC, which down-regulates the beta-catenin levels was analysed for mutations. Overall mRNA levels of beta-catenin were significantly increased in the tumour samples compared with the matched normal gastric mucosa (P < 0.05). Increased beta-catenin mRNA levels were significantly more frequent in intestinal-type gastric cancers as compared to diffuse-type gastric cancers (P < 0.01). Six out of 20 tumours exhibited >6-fold increased beta-catenin mRNA levels as compared with normal mucosa. APC gene mutations were found in four cases. A beta-catenin gene mutation was identified only in one intestinal-type gastric cancer exhibiting a massive overexpression of beta-catenin mRNA in the tumour. In intestinal-type gastric cancers beta-catenin mRNA levels are greatly enhanced. APC and beta-catenin gene mutations are also present primarily in intestinal-type gastric cancers. These findings support the hypothesis that in intestinal-type gastric cancers the accumulation of beta-catenin protein may result from impaired degradation of the beta-catenin protein due to alterations of the beta-catenin and APC genes, as well as from enhanced beta-catenin transcription which is present in the great majority of intestinal-type gastric cancers.
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PMID:Increased beta-catenin mRNA levels and mutational alterations of the APC and beta-catenin gene are present in intestinal-type gastric cancer. 1175 28

WNT - beta-catenin - TCF signaling pathway is activated by Xenopus wnt-8 (Xwnt-8) during Xenopus early development, and dysregulated activation of beta-catenin - TCF signaling pathway in mammalian cells leads to carcinogenesis. We have previously cloned and characterized human WNT8A, one of human orthologues of Xwnt-8. Here, we cloned and characterized human WNT8B by using bioinformatics, cDNA-PCR, and RACE. WNT8B gene of about 23-kb in size consisted of six exons, and encoded a 351-amino-acid polypeptide with the N-terminal signal peptide and two N-linked glycosylation sites. C-terminal region of WNT8B, WNT8A, WNT2, and WNT2B were longer than that of other human WNTs. Thirty-five nucleotide changes between WNT8B isolated by us and WNT8B isolated by another group resulted in Gly230Ala and Arg284Leu amino-acid substitutions. Gly230 and Arg284 of WNT8B were conserved in WNT8A. Gly230-Arg284 WNT8B allele was also identified in human genome draft sequences AL133352.10, AL359759.18, and human EST BF732616. These results indicate that the Gly230-Arg284 WNT8B cDNA isolated in this study is derived from the more common WNT8B allele. WNT8B mRNAs of 4.4- and 3.5-kb in size were weakly detected in a colorectal cancer cell line SW480, but were undetectable in any normal human tissues by using Northern blot analyses. WNT8B was significantly up-regulated in gastric cancer cell lines KATO-III (signet-ring cell carcinoma) and MKN45 (poorly differentiated adenocarcinoma), and also in 5 out of 10 cases of primary gastric cancer. WNT8B might play key roles in gastric cancer through activation of the beta-catenin - TCF signaling pathway.
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PMID:Up-regulation of WNT8B mRNA in human gastric cancer. 1178 99

We have previously cloned and characterized human WNT2B/WNT13, WNT3, WNT3A, WNT5B, WNT6, WNT7B, WNT8A, WNT10A, WNT10B, WNT11, WNT14, and WNT14B/WNT15 by using bioinformatics, cDNA-library screening, cDNA-PCR, and RACE. WNT3 and WNT3A genes are two human paralogues of mouse proto-oncogene Wnt3, which induces carcinogenesis through activation of the beta-catenin - TCF signaling pathway. Here, regulation of WNT3 and WNT3A mRNAs in human cancer cell lines was investigated. WNT3 and WNT3A mRNAs were co-expressed in an embryonal carcinoma cell line NT2, which is reported to differentiate into postmitotic CNS neurons by treatment with retinoic acid for two weeks. Expression level of WNT3 mRNA in NT2 cells was not changed during 72 h after retinoic acid treatment, while expression of WNT3A mRNA was down-regulated in NT2 cells by retinoic acid. WNT3 and WNT3A mRNAs were also co-expressed in a breast cancer cell line MCF-7, and were down-regulated together by beta-estradiol in MCF-7 cells. Expression of WNT3 mRNA in a gastric cancer cell line MKN45 was not changed after treatment with tumor necrosis factor alpha (TNFalpha) or interferon gamma (IFNgamma), and that of WNT3A mRNA was undetectable before and after treatment with TNFalpha or IFNgamma. WNT3A, down-regulated by retinoic acid in NT2 cells, might play key roles in the maintenance of NT2 cells in the undifferentiated proliferation stage through activation of the beta-catenin - TCF signaling pathway.
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PMID:Regulation of WNT3 and WNT3A mRNAs in human cancer cell lines NT2, MCF-7, and MKN45. 1178 4

Wnt signaling pathway is important for development and carcinogenesis. Alterations of this pathway, such as mutations in adenomatous polyposis coli (APC) gene and activation mutations of beta-catenin, would result in stabilization of beta-catenin and subsequent translocation to nucleus where genes are transcribed. Recently, a receptor of Wnt, FzE3 was found to be up-regulated in esophageal carcinoma while a non-receptor antagonist of Wnt, secreted frizzled related protein (hsFRP) was found to be down-regulated in some cancer. These findings suggested that FzE3 is a potential oncogene while hsFRP is a potential tumor suppressor gene. We aimed to investigate whether FzE3 and hsFRP were altered in gastric cancer. Twelve cases of gastric cancer, including 7 cases of intestinal type, 4 cases of diffuse type and I case of mixed type, were studied. FzE3 and hsFRP mRNAs were expressed in most of the paired normal gastric tissues. FzE3 was over-expressed in 9 cases (75%) of gastric carcinoma tissues while hsFRP was down-regulated in 2 cases (16%). Beta-catenin nuclear staining was identified in 3 cases (27%) and cyclin D1 was expressed in 5 cases (41%) of cancer samples. All these cases were associated with either up-regulation of FzE3 or down-regulation of hsFRP. Our results suggested that alterations of FzE3 or hsFRP were frequent in gastric cancer. These provide alternative mechanisms leading to activation of Wnt signaling pathway in gastric carcinogenesis.
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PMID:Alterations of frizzled (FzE3) and secreted frizzled related protein (hsFRP) expression in gastric cancer. 1179 16

SOX transcription factors with high-mobility-group DNA-binding domain (HMG box) play key roles in embryogenesis. Some members of the SOX family are negative regulators of the WNT-beta-catenin-TCF signaling pathway. We have previously cloned and characterized human SOX17, constituting a subfamily with SOX7 and SOX18. Another group mapped SOX7 gene to human chromosome 8p22, and reported almost ubiquitous expression of 5.0-kb SOX7 mRNA in human normal tissues. Here, expression of SOX7 mRNA was investigated by using SOX7 specific probe, which hybridized to 3.8-kb human SOX7 mRNA, but not to 5.0-kb mRNA. SOX7 mRNA was relatively highly expressed in adult lung, trachea, lymph node, placenta, fetal lung, and heart. In adult heart, SOX7 mRNA was more highly expressed in ventricules, inter-ventricular septum and apex than in atriums. SOX7 mRNA was significantly up-regulated in pancreatic cancer cell lines BxPC-3, PSN-1, Hs766T, and in 4 cases out of 8 cases of primary gastric cancer. SOX7 mRNA was relatively highly expressed in a gastric cancer cell line MKN45, esophageal cancer cell lines TE2, TE3, TE4, TE5, TE7, TE8, TE11, TE12, and TE13. On the other hand, SOX7 mRNA was significantly down-regulated in 7 out of 18 cases of primary colorectal tumors, in 4 out of 9 cases of primary breast cancer, in 4 out of 14 cases of primary kidney tumors, and also in some cases of primary lung and prostate cancer. SOX7 gene might be one of cancer-associated genes on human chromosome 8p22.
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PMID:Expression of human SOX7 in normal tissues and tumors. 1189 28

Secreted-type glycoprotein WNTs bind to seven-transmembrane-type WNT receptors encoded by Frizzled genes (FZD1-FZD10) to transduce signals to the beta-catenin--TCF pathway, the JNK pathway, or the Ca(2+)-releasing pathway. Wrch1 gene is a down-stream target gene of Wnt1 in C57MG cells, and encodes a Cdc42-related GTPase with the potential to activate the JNK pathway. Here, we isolated human WRCH1 cDNAs (accession no. AB074878) from gastric cancer cell lines OKAJIMA, MKN7, MKN28, MKN45, MKN74, and KATO-III, all of which showed a nucleotide substitution (343 C-->T) without amino-acid substitution compared with WRCH1 cDNA isolated by another group. WRCH1 gene, consisting of at least 3 exons, was mapped to human chromosome 1q42.11-q42.3 by using bioinformatics. WRCH1 mRNA was more highly expressed in corpus callosum, hippocampus, cerebral cortex, and also in several parts within adult brain than in other normal tissues including stomach, pancreas, and placenta. Amounts of WRCH1 mRNA in 40 human cancer cell lines were lower than that in normal stomach, pancreas, or placenta. WRCH1 mRNA was significantly up-regulated in 4 cases of primary kidney tumors, 1 case each of primary colon, gastric, breast, ovarian, and uterus cancer. On the other hand, WRCH1 mRNA was significantly down-regulated in 6 cases of colon tumors, 2 cases of primary kidney cancer and breast cancer. Expression of WRCH1 mRNA was down-regulated by beta-estradiol in MCF-7 cells. This is the first report on comprehensive expression analyses on WRCH1 mRNA.
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PMID:Expression of WRCH1 in human cancer and down-regulation of WRCH1 by beta-estradiol in MCF-7 cells. 1189 24

FRAT1 and FRAT2 genes, clustered in human chromosome 10q24, are human homologues to mouse proto-oncogene Frat1, which promotes carcinogenesis through activation of the WNT - beta-catenin - TCF signaling pathway. FRAT1 and FRAT2 mRNAs are up-regulated together in a gastric cancer cell line TMK1, and also in 2 out of 10 cases of primary gastric cancer. Here, we isolated FRAT1 cDNA (AB074890), which showed two amino-acid substitutions (Gln57X and His58Asp) compared with human FRAT1 cDNA previously reported by another group (U58975). The Gln57-His58 FRAT1 allele isolated in this study was also identified in human genome draft sequences. FRAT1 mRNA was almost ubiquitously expressed in human pancreatic cancer cell lines. Expression level of FRAT1 mRNA was relatively higher in esophageal cancer cell lines TE2, TE3, TE4, a cervical cancer cell line SKG-IIIa, and breast cancer cell lines MCF-7 and T-47D. Expression level of FRAT1 mRNA was not significantly changed after all-trans retinoic-acid treatment in NT2 cells with the potential of neuronal differentiation. Expression of FRAT1 mRNA in MCF-7 cells derived from breast cancer was down-regulated by beta-estradiol. This is the first report on isolation of FRAT1 cDNA derived from the more common FRAT1 allele, and also on regulation of FRAT1 mRNA in human cancer cells.
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PMID:Molecular cloning and expression of proto-oncogene FRAT1 in human cancer. 1189 25

WNT signals are transduced to the JNK pathway, the Ca2+-releasing pathway, or the beta-catenin - TCF pathway through seven-transmembrane-type WNT receptors encoded by Frizzled genes (FZD1-FZD10). WRCH1/ARHV and CDC42 are potentially implicated in the WNT-JNK pathway. Here, WRCH2/ARHV cDNAs were isolated by using bioinformatics and cDNA-PCR. WRCH2 gene, consisting of at least 3 exons, encoded a 236-amino-acid protein with proline-rich domain and GTPase domain. WRCH2 was homologous to WRCH1 (55.4% total-amino-acid identity) and CDC42 (43.5% total-amino-acid identity). WRCH2 gene was located on human chromosome 15q15, which is one of fragile sites in the human genome. A single nucleotide substitution (632 Gright curved arrow A) was identified between WRCH2 cDNA and human genome draft sequences, which resulted in Arg177Lys amino-acid substitution. WRCH2 mRNA was relatively highly expressed in pancreas, placenta, and fetal brain. WRCH2 mRNA was over-expressed in TMK1 (gastric cancer), Hs700T (pancreatic cancer), HeLa S3 (cervical cancer), and A549 (lung cancer). WRCH2 mRNA was moderately expressed in MKN74, MKN45, MKN28, KATO-III (gastric cancer), HL-60 (pro-myelocytic leukemia), Raji (Burkitt's lymphoma), and SW480 (colorectal cancer). WRCH2 mRNA was up-regulated in 3 out of 8 cases of primary gastric cancer. Because Wrch1 can activate PAK1 and JNK1, and induce filopodium formation and stress fiber dissolution, over-expression of WRCH2 mRNA in human cancer cells might also lead to more malignant phenotype.
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PMID:Molecular cloning and characterization of WRCH2 on human chromosome 15q15. 1195 92

WNT signaling pathway is implicated in carcinogenesis and embryogenesis. WNT signal is transduced to the beta-catenin - TCF pathway, the JNK pathway, or the Ca2+-releasing pathway through seven-transmembrane-type WNT receptors encoded by Frizzled (FZD) genes. Xenopus Strabismus (Stbm) is a tetra-spanning transmembrane protein interacting with Dishevelled, and is a negative regulator of the WNT - beta-catenin - TCF signaling pathway. STB1/KIAA1215/VANGL2 is a human orthologue of Xenopus Stbm (90.6% total-amino-acid identity). Here, STB2/VANGL1 gene fragments were identified in human genome draft sequences by using bioinformatics, and STB2 cDNAs were isolated by using cDNA-PCR. STB2 gene consisted of at lest 7 exons, and encoded a 524-amino-acid protein with 4 transmembrane domains and the C-terminal Ser/Thr-X-Val motif. Human STB2 was homologous to human STB1 (73.1% total-amino-acid identity) and Xenopus Stbm (72.7% total-amino-acid identity). STB2 gene was clustered with Calsequestrin 2 (CASQ2) gene in tail-to-tail manner (interval less than 5.0 kb), and CASQ2 gene is mapped to human chromosome 1p11-p13.3 or linked to human chromosome 1p13-p21. STB2 mRNAs of 4.8- and 6.8-kb in size were expressed almost ubiquitously in various normal tissues. STB2 mRNA was significantly up-regulated in gastric cancer cell lines MKN28, MKN74, pancreatic cancer cell lines BxPC-3, PSN-1 and Hs766T. On the other hand, STB2 mRNA was significantly down-regulated in a pancreatic cancer cell line AsPC-1. This is the first report on molecular cloning and characterization of STB2.
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PMID:Molecular cloning and characterization of Strabismus 2 (STB2). 1195 95


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