• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5101-5104
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• 2012

Background: Genetic mutation is a significant factor in colon CA pathogenesis. Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary disease characterized by multiple colorectal adenomatous polyps affecting a number of cases in the family. This report focuses on a family with attenuated familial adenomatous polyposis (AFAP) with exon 4 mutation, c.481C>T p.Q161X of the APC gene. Methods: We analyzed 20 members of a family with AFAP. Clinical and endoscopic data were collected for phenotype determination. Genetic analysis was also performed by direct sequencing of the APC gene. Result: Five patients with a phenotype of AFAP were found. Endoscopic polyposis was demonstrated among the second generation with genotype mutation of the disease (age > 50 years) consistent with delayed phenotypic adenomatous polyposis in AFAP. APC gene mutation was identified in exon 4 of the APC gene, with mutation points of c.481C>T p.Q161X. Laparoscopic subtotal colectomy was performed to prevent carcinogenesis. Conclusion: A family with attenuated familial adenomatous polyposis of APC related to exon 4 mutation, c.481C>T p.Q161X, was reported and the phenotypic finding was confirmed by endoscopic examination. Genetic mutation analysis might be advantageous in AFAP for long term colon cancer prevention and management due to subtle or asymptomatic phenotype presentation in early adulthood.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4915-4920
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• 2015

Background: : Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disease mainly caused by mutations of the adenomatous polyposis coli (APC) gene with almost complete penetrance. These colorectal polyps are precancerous lesions that will inevitable develop into colorectal cancer at the median age of 40-year old if total proctocolectomy is not performed. So identification of APC germline mutations has great implications for genetic counseling and management of FAP patients. In this study, we screened APC germline mutations in Chinese FAP patients, in order to find novel mutations and the APC gene germline mutation characteristics of Chinese FAP patients. Materials and Methods: The FAP patients were diagnosed by clinical manifestations, family histories, endoscope and biopsy. Then patients peripheral blood samples were collected, afterwards, genomic DNA was extracted. The mutation analysis of the APC gene was conducted by direct polymerase chain reaction (PCR) sequencing for micromutations and multiplex ligation-dependent probe amplification (MLPA) for large duplications and/or deletions. Results: We found 6 micromutations out of 14 FAP pedigrees, while there were no large duplications and/or deletions found. These germline mutations are c.5432C>T(p. Ser1811Leu), two c.3926_3930delAAAAG (p.Glu1309AspfsX4), c.3921_3924delAAAA (p.Ile1307MetfsX13), c3184_3187delCAAA(p.Gln1061AspfsX59) and c4127_4126delAT (p.Tyr1376LysfsX9), respectively, and all deletion mutations resulted in a premature stop codon. At the same time, we found c.3921_3924delAAAA and two c.3926_3930delAAAAG are located in AAAAG short tandem repeats, c3184_3187delCAAA is located in the CAAA interrupted direct repeats, and c4127_4128 del AT is located in the 5'-CCTGAACA-3', 3'-ACAAGTCC-5 palindromes (inverted repeats) of the APC gene. Furthermore, deletion mutations are mostly located at condon 1309. Conclusions: Though there were no novel mutations found as the pathogenic gene of FAP in this study, we found nucleotide sequence containing short tandem repeats and palindromes (inverted repeats), especially the 5 bp base deletion at codon 1309, are mutations in high incidence area in APC gene,.

• Korean Journal of Head & Neck Oncology
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• v.20 no.2
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• pp.147-155
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• 2004

Objectives: Head and neck squamous cell carcinoma (HNSCC) is the most common head and neck malignant tumor. The molecular genetic changes involving both oncogenes and tumor suppressor genes are known to be involved in head and neck squamous cell carcinogenesis, but the roles of the known tumor suppressor genes in carcinogenesis are not fully elucidated. The objectives of this study are to demonstrate the genetic alterations including the loss of heterozygosity (LOH) , amplification, and microsatellite instability of known tumor suppressor genes in HNSCC and to evaluate the relationship between genetic alterations of tumor suppressor genes and clinicopathologic features. Materials and Methods: Genetic alterations of 10 micro satellite markers of the 6 known tumor suppressor genes (APC, EXT1, DPC4, p16, FHIT, and PTEN) were analysed by DNA-PCR in paraffin-embedded histologically confirmed HNSCC specimens. Results: The genetic alterations of tumor suppressor genes were found frequently. Among the genetic alterations, LOH was most frequently found one. LOH was found frequently in APC (45.4%), EXT1 (36.4%), DPC4 (54.5%), and p16 (50%), but not found in FHIT. Also, the author found that abnormalities of APC gene was related to cervical lymph node metastasis and recurrence and that abnormalities of EXT1 gene were coexisted with those of APC gene or DPC4 gene. But these coexistences had no correlation with clinical features. Conclusion: These results suggested that APC, EXT1, p16, and DPC4 genes might play important roles and multiple tumor suppressor genes may participate dependently or independently in the carcinogenesis of HNSCC. These results also suggested that APC gene might relate to prognosis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.121-126
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• 2013

Background: Significance of HPV infection and genic mutation of APC and K-ras in rectal cancer has been investigated but not clarified. The objective of our study was to investigate these parameters in patients with rectal cancer to analyze correlations with biological behaviour, to determine relationships among the three, and also to demonstrate survival prognosis effects. Methods: From December 2007 to September 2008, 75 rectal cancer cases confirmed by histopathology in the Tumor Hospital of Xinjiang Medical University were enrolled. The control group consisted of normal rectal mucous membrane taken simultaneously, a least 10 cm distant from the carcinoma fringe. HPV DNA, the MCR of APC and exon-1 of K-ras were detected by PCR and PCR-SSCP. All results were analyzed in relation to clinical pathological material, using chi-square and correlation analysis via SPSS.13 and Fisher's Exact Probability via STATA. 9.0. All 75 patients were followed up for survival analysis using Kaplan-Meier and Log-rank tests. Results: 55 out of 75 cases demonstrated gene HPV L1 while it was notdetected in normal rectal mucosa tissue. HPV infection was correlated with age and lymphatic metastasis (P<0.05) but not other characteristics, such as ethnicity, tumor size, histological type, tumor type, Duke's stage and infiltration depth. Some 43 cases exhibited APC genic mutation (57.3%) and 34 K-ras genic mutation (45.3%). APC genic mutation was correlated with gender(P<0.05), but not age, histological type, infiltration depth, lymphatic metastasis and Duke's stage. In 55 cases of rectal cancer with HPV infection, there were 31 cases with genic mutation of APC (56.4%) and 24 with genic mutation of K-ras (43.6%). For the 20 cases of rectal cancer with non-HPV infection, the figures were 12 cases (60%) and 10 (50.0%), respectively, with no significant relation. Survival analysis showed no statistical significance for K-ras genic mutation, APC genic mutation or HPV infection (P>0.05). However, the survival time of the patients with HPV infection was a little shorter than in cases without HPV infection. Conclusions: Our results suggest that HPV infection might be an important factor to bring about malignant phenotype of rectal cancer and influence prognosis. Genic mutation of APC and K-ras might be common early molecular events of rectal cancer, but without prognostic effects on medium-term or early stage patients with rectal cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.1945-1952
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• 2015

Inflammatory bowel disease (IBD) is a disease strongly associated with colorectal cancer (CRC) as a well-known precancerous condition. Alterations in DNA methylation and mutation in K-ras are believed to play an early etiopathogenic role in CRC and may also an initiating event through deregulation of molecular signaling. Epigenetic silencing of APC and SFRP2 in the WNT signaling pathway may also be involved in IBD-CRC. The role of aberrant DNA methylation in precancerous state of colorectal cancer (CRC) is under intensive investigation worldwide. The aim of this study was to investigate the status of promoter methylation of MGMT-B, APC1A and SFRP2 genes, in inflamed and normal colon tissues of patients with IBD compared with control normal tissues. A total of 52 IBD tissues as well as corresponding normal tissues and 30 samples from healthy participants were obtained. We determined promoter methylation status of MGMT-B, SFRP2 and APC1A genes by chemical treatment with sodium bisulfite and subsequent MSP. The most frequently methylated locus was MGMT-B (71%; 34 of 48), followed by SFRP2 (66.6 %; 32 of 48), and APC1A (43.7%; 21 of 48). Our study demonstrated for the first time that hypermethylation of the MGMT-B and the SFRP2 gene promoter regions might be involved in IBD development. Methylation of MGMT-B and SFRP2 in IBD patients may provide a method for early detection of IBD-associated neoplasia.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2719-2725
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• 2014

Background: Secreted frizzled-related protein (SFRP) genes, new tumor suppressor genes, are negative regulators of the Wnt pathway whose alteration is associated with various tumors. In ovarian cancer, SFRPs genes promoter methylation can lead to gene inactivation. This study investigated mechanisms of SFRP and adenomatous polyposis coli (APC) genes silencing in ovarian cancer infected with high risk human papillomavirus. Materials and Methods: DNA was extracted from 200 formalin-fixed paraffin-embedded ovarian cancer and their normal adjacent tissues (NAT) and DNA methylation was detected by methylation specific PCR (MSP). High risk human papillomavirus (HPV) was detected by nested PCR with consensus primers to amplify a broad spectrum of HPV genotypes. Results: The percentages of SFRP and APC genes with methylation were significantly higher in ovarian cancer tissues infected with high risk HPV compared to NAT. The methylated studied genes were associated with suppression in their gene expression. Conclusion: This finding highlights the possible role of the high risk HPV virus in ovarian carcinogenesis or in facilitating cancer progression by suppression of SFRP and APC genes via DNA methylation.

• BMB Reports
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• v.55 no.12
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• pp.609-614
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• 2022

Mutation of the gene for adenomatous polyposis coli (APC), as seen in Apc^Min/+ mice, leads to intestinal adenomas and carcinomas via stabilization of β-catenin. Transmembrane 4 L six family member 5 (TM4SF5) is involved in the development of non-alcoholic fatty liver disease, fibrosis, and cancer. However, the functional linkage between TM4SF5 and APC or β-catenin has not been investigated for pathological outcomes. After interbreeding Apc^Min/+ with TM4SF5-overexpressing transgenic (Tg^TM4SF5) mice, we explored pathological outcomes in the intestines and livers of the offspring. The intestines of 26-week-old dual-transgenic mice (Apc^Min/+:Tg^TM4SF5) had intramucosal adenocarcinomas beyond the single-crypt adenomas in Apc^Min/+ mice. Additional TM4SF5 overexpression increased the stabilization of β-catenin via reduced glycogen synthase kinase 3β (GSK3β) phosphorylation on Ser9. Additionally, the livers of the dualtransgenic mice showed distinct sinusoidal dilatation and features of hepatic portal hypertension associated with fibrosis, more than did the relatively normal livers in Apc^Min/+ mice. Interestingly, TM4SF5 overexpression in the liver was positively linked to increased GSK3β phosphorylation (opposite to that seen in the colon), β-catenin level, and extracellular matrix (ECM) protein expression, indicating fibrotic phenotypes. Consistent with these results, 78-week-old Tg^TM4SF5 mice similarly had sinusoidal dilatation, immune cell infiltration, and fibrosis. Altogether, systemic overexpression of TM4SF5 aggravates pathological abnormalities in both the colon and the liver.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2201-2205
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• 2013

Colorectal cancer (CRC) is one of the most common cancers in many parts of the world. Its development is a multi-step process involving three distinct stages, initiation that alters the molecular message of a normal cell, followed by promotion and progression that ultimately generates a phenotypically altered transformed malignant cell. Reports have suggested an association of the phosphoinositide-3-kinase (PI3K)/Akt pathway with colon tumorigenesis. Activation of Akt signaling and impaired expression of phosphatase and tensin homolog (PTEN) (a negative regulator of Akt) has been reported in 60-70% of human colon cancers and inhibitors of PI3K/Akt signaling have been suggested as potential therapeutic agents. Around 80% of human colon tumors possess mutations in the APC gene and half of the remainder feature ${\beta}$-catenin gene mutations which affect downstream signaling of the PI3K/Akt pathway. In recent years, there has been a great focus in targeting these signaling pathways, with natural and synthetic drugs reducing the tumor burden in different experiment models. In this review we survey the role of PI3K/Akt/mTOR and Wnt signaling in CRC.

• Journal of Veterinary Clinics
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• v.8 no.1
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• pp.1-10
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• 1991

The B-lymphocyte differentiation from committed B-cell progenitors to antibody-secreting cells was discussed. B-cell progenitors derived from hematopoietic stem cells undergo the rearrangement of immunoglobulin(Ig) gene. The earliest cells as B-cell precursors have cytoplasmic Is(${\mu}$ chain). The entire Is molecule is expressed on the surface after synthesis of L chain. The resting B cells(Go stage) stimulated by binding antigen via Ig-receptors are activated(G$_1$ stage) and followed by proliferation(S stage), coupled with further selection(affinity maturation. class switch). The production of antibody against a particular antigen depends on the activation of B cells with surface Is capable of reacting with that antigen. This process does not occur in isolation but is controlled by helper and suppressor T cells and antigen presenting cells(APC). The mechanism of T cell-dependent B-cell response for production of antibody is largely explained by the cell to cell cooperation and soluble helper factors of T cells. 1) The antigen specific B cells and helper T cells are linked by Is-receptors, leading to the delivery of helper signals to the B cells. 2) Helper T cells recognize the processed antigen-derived peptides with the MHC class II molecules(la antigen) and is stimulated to secrete B-cell proliferation and differentiation factors which activate B cells of different antigenic specificity. The two models are shown currently 1) At low antigen concentration, only the antigen-specific B cell binds antigen and presents antigen-derived peptides with la molecules to helper T cells, which are stimulated to secrete cytokines(IL-4, IL-5, etc.) and 2) At high antigen concentration, antigen-derived peptides are presented by specific B cells, by B cells that endocytose the antigens, as well as by APC Cytokines secreted from helper T cells also lead to the activation of B cells and even bystander B cells in the on- vironmment and differentiate them into antibody-secreting plasma cells.

• IMMUNE NETWORK
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• v.6 no.4
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• pp.179-184
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• 2006

Background: Identification of antigen-specific T cells has yielded valuable information on pathologic process and the disease state. Assays for quantification of inflammatory cytokines or lytic-granule molecules have been generally used to evaluate antigen specific T cell response, however their applicability have been hampered due to the limited source of autologous antigen-presenting target cells (APC). Methods: K562, a leukemic cell line deficient of human leukocyte antigen (HLA), was transfected with a gene encoding HLA-A*02 (K562/ A*02) and its function as stimulator cells in inducing activation of HLA-matched T cells was evaluated by IFN-${\gamma}$ enzyme linked immunospot (ELISPOT) assay. Results: The stable transfectant K562/ A*02 pulsed with HLA- A*02 restricted peptide could specifically induce IFN-${\gamma}$ secretion by CD8+ T cells compared to no detectable secretion by CD4+ T cells. However, CD56+ NK cells secreted IFN-${\gamma}$ in both K562/ A*02 with peptide and without peptide. The number of IFN-${\gamma}$ secreted CD8+ T cells was increased according to the ratio of T cells to K562 and peptide concentration. Formalin-fixed K562/ A*02 showed similar antigen presenting function to live K562/ A*02. Moreover, K562/ A*02 could present antigenicpeptide to not only A*0201 restricted CD8+ T cells but also CD8+ T cells from A*0206 donor. Conclusion: These results suggest that K562/ A*02 could be generally used as target having specificity and negligible background for measuring CD8+ T cell responses and selective use of K562 with responsder matched HLA molecules on its surface as APC may circumvent the limitation of providing HLA-matched autologous target cells.