No abstract available.
Colorectal Neoplasms/*genetics/*mortality ; CpG Islands/*physiology ; *DNA Methylation ; Female ; Humans ; Male ; *Phenotype

No abstract available.
Colorectal Neoplasms/*genetics/*mortality ; CpG Islands/*physiology ; *DNA Methylation ; Female ; Humans ; Male ; *Phenotype

BACKGROUND/AIMS: CpG island methylator phenotype (CIMP)- high colorectal cancers (CRCs) have distinct clinicopathological features from their CIMP-low/negative CRC counterparts. However, controversy exists regarding the prognosis of CRC according to the CIMP status. Therefore, this study examined the prognosis of Korean patients with colon cancer according to the CIMP status. METHODS: Among a previous cohort population with CRC, a total of 154 patients with colon cancer who had available tissue for DNA extraction were included in the study. CIMP-high was defined as 3/5 methylated markers using the five-marker panel (CACNA1G, IGF2, NEUROG1, RUNX3, and SOCS1). RESULTS: CIMP-high and CIMP-low/negative cancers were observed in 27 patients (17.5%) and 127 patients (82.5%), respectively. Multivariate analysis adjusting for age, gender, tumor location, tumor stage and CIMP and microsatellite instability (MSI) statuses indicated that CIMP-high colon cancers were associated with a significant increase in colon cancer-specific mortality (hazard ratio [HR], 3.23; 95% confidence interval [CI], 1.20 to 8.69; p=0.02). In microsatellite stable cancers, CIMP-high cancer had a poor survival outcome compared to CIMP-low/negative cancer (HR, 2.91; 95% CI, 1.02 to 8.27; p=0.04). CONCLUSIONS: Regardless of the MSI status, CIMP-high cancers had poor survival outcomes in Korean patients.
Adult ; Age Factors ; Aged ; Colorectal Neoplasms/*genetics/*mortality ; CpG Islands/*physiology ; *DNA Methylation ; Female ; Humans ; Male ; Microsatellite Instability ; Middle Aged ; Multivariate Analysis ; Neoplasm Staging ; *Phenotype ; Prognosis ; Republic of Korea ; Sex Factors ; Survival Analysis

BACKGROUND/AIMS: CpG island methylator phenotype (CIMP)- high colorectal cancers (CRCs) have distinct clinicopathological features from their CIMP-low/negative CRC counterparts. However, controversy exists regarding the prognosis of CRC according to the CIMP status. Therefore, this study examined the prognosis of Korean patients with colon cancer according to the CIMP status. METHODS: Among a previous cohort population with CRC, a total of 154 patients with colon cancer who had available tissue for DNA extraction were included in the study. CIMP-high was defined as 3/5 methylated markers using the five-marker panel (CACNA1G, IGF2, NEUROG1, RUNX3, and SOCS1). RESULTS: CIMP-high and CIMP-low/negative cancers were observed in 27 patients (17.5%) and 127 patients (82.5%), respectively. Multivariate analysis adjusting for age, gender, tumor location, tumor stage and CIMP and microsatellite instability (MSI) statuses indicated that CIMP-high colon cancers were associated with a significant increase in colon cancer-specific mortality (hazard ratio [HR], 3.23; 95% confidence interval [CI], 1.20 to 8.69; p=0.02). In microsatellite stable cancers, CIMP-high cancer had a poor survival outcome compared to CIMP-low/negative cancer (HR, 2.91; 95% CI, 1.02 to 8.27; p=0.04). CONCLUSIONS: Regardless of the MSI status, CIMP-high cancers had poor survival outcomes in Korean patients.
Adult ; Age Factors ; Aged ; Colorectal Neoplasms/*genetics/*mortality ; CpG Islands/*physiology ; *DNA Methylation ; Female ; Humans ; Male ; Microsatellite Instability ; Middle Aged ; Multivariate Analysis ; Neoplasm Staging ; *Phenotype ; Prognosis ; Republic of Korea ; Sex Factors ; Survival Analysis

Recent evidence shows that transcriptional silencing as a consequence of hypermethylation of CpG islands is an important mechanism in the inactivation of p16INK4 tumor suppressor gene. This study is designed to clarify the significance of p16INK4 hypermethylation in 23 cases of glioblastomas (GBMs) by methylation-specific polymerase chain reaction (PCR) and p16 immunostaining. Fourteen cases (60.9%) out of 23 GBMs revealed hypermethylation on p16. p16 immunostaining revealed that 13 (93%) of these 14 hypermethylation cases showed complete loss of immunoreactivity and only one (7%) case retained immunoreactivity. Among 9 methylation-negative cases, 4 were immunonegative, which might be related to mutations or deletions other than hypermethylation. The most significant finding was that of 17 cases with immunonegativity, 13 cases (76.5%) showed hypermethylation. We reconfirmed that p16 hypermethylation may be one of the major mechanisms of tumorigenesis of GBMs and the results between the methylation specific-PCR study and p16 immunostaining had a good correlation.
5' Untranslated Regions/metabolism* ; 5' Untranslated Regions/genetics ; Adult ; Antisense Elements (Genetics) ; Brain Neoplasms/pathology ; Brain Neoplasms/genetics* ; Brain Neoplasms/chemistry ; CpG Islands/physiology* ; DNA Methylation* ; Female ; Gene Silencing/physiology ; Glioblastoma/pathology ; Glioblastoma/genetics* ; Glioblastoma/chemistry ; Human ; Male ; Middle Age ; Polymerase Chain Reaction ; Protein p16/genetics* ; Protein p16/analysis

OBJECTIVETo investigate the status of hypermethylation in the promoter 1A region of the adenomatus polyposis coli (APC) gene in 3 familial adenomatous polyposis (FAP) pedigrees and to screen large fragment deletions in the APC gene.

METHODSDNA from tumor tissues and corresponding normal tissues of 5 FAP patients was modified by sodium bisulfite. Then the methylation status of the APC gene was analyzed by methylation specific-PCR (MSP) and DNA sequencing. Multiplex ligation-dependent probe amplification (MLPA) was used to screen aberrations involving large fragments from all the 15 exons and promoter region of APC gene.

RESULTSNo methylation was present in normal tissues. Hypermethylation was found in tumor tissues of one proband and her son. Loss of heterozygosity was observed in another patient from the same FAP family.

CONCLUSIONAberrant methylation of the APC promoter region provides an important mechanism for impairing APC function and may occur early during colon neoplasia progression. Loss of heterozygosity may play a role in patients with classical polyposis.

Adenomatous Polyposis Coli ; genetics ; Adenomatous Polyposis Coli Protein ; genetics ; Adult ; Base Sequence ; Colorectal Neoplasms ; genetics ; CpG Islands ; DNA Methylation ; DNA, Neoplasm ; Female ; Gene Expression Regulation, Neoplastic ; Genes, APC ; physiology ; Heterozygote ; Humans ; Loss of Heterozygosity ; Male ; Polymerase Chain Reaction ; Promoter Regions, Genetic ; physiology

Recent evidence suggests that gastric mucosal injury induces adaptive changes in DNA methylation. In this study, the methylation status of the key tissue-specific genes in normal gastric mucosa of healthy individuals and cancer patients was evaluated. The methylation-variable sites of 14 genes, including ulcer-healing genes (TFF1, TFF2, CDH1, and PPARG), were chosen from the CpG-island margins or non-island CpGs near the transcription start sites. The healthy individuals as well as the normal gastric mucosa of 23 ulcer, 21 non-invasive cancer, and 53 cancer patients were examined by semiquantitative methylation-specific polymerase chain reaction (PCR) analysis. The ulcer-healing genes were concurrently methylated with other genes depending on the presence or absence of CpG-islands in the normal mucosa of healthy individuals. Both the TFF2 and PPARG genes were frequently undermethylated in ulcer patients. The over- or intermediate-methylated TFF2 and undermethylated PPARG genes was more common in stage-1 cancer patients (71%) than in healthy individuals (10%; odds ratio [OR], 21.9) and non-invasive cancer patients (21%; OR, 8.9). The TFF2-PPARG methylation pattern of cancer patients was stronger in the older-age group (> or =55 yr; OR, 43.6). These results suggest that the combined methylation pattern of ulcer-healing genes serves as a sensitive marker for predicting cancer-prone gastric mucosa.
Biological Markers/metabolism ; Cadherins/genetics ; CpG Islands ; *DNA Methylation ; Female ; *Gastric Mucosa/pathology/physiology ; Gene Expression Regulation, Neoplastic ; Growth Substances/genetics ; Humans ; Male ; Middle Aged ; Neoplasm Invasiveness ; PPAR gamma/genetics ; Peptides/genetics ; *Stomach Neoplasms/genetics/pathology ; *Stomach Ulcer/genetics/pathology ; Tumor Suppressor Proteins/genetics ; Wound Healing/*genetics

OBJECTIVETo investigate the methylation status of 5'CpG island of insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) in colorectal cancer and its relationship with gene expression and clinicopathologic parameters.

METHODSSemi-quantitative reverse transcription-PCR (RT-PCR) was used to detect the expression of IGFBP-rP1 in 46 cases of colorectal cancer and their matched normal mucosa. Methylation-specific PCR (MSP) was applied to evaluate the methylation status of 5'CpG island of IGFBP-rP1. Colon cancer cell lines LoVo and SW620 were treated with demethylation agent 5-aza-2'-deoxycytidine (5-aza-dC), followed by RT-PCR and MSP detection.

RESULTSAt the mRNA level, the expression of IGFBP-rP1 was higher in colorectal cancer tissue than that in the matched normal mucosa (P < 0.05). IGFBP-rP1 was methylated in 28/46 (60.9%) cases of colorectal cancer and 37/46 (80.4%) matched normal mucosa samples (P < 0.05). A negative correlation was found between IGFBP-rP1 expression and its methylation status. The expression of IGFBP-rP1 was restored in LoVo and SW620 after treatment with 5-aza-dC and MSP confirmation of its demethylation status. No relationships was found between the methylation status and clinicopathologic parameters.

CONCLUSIONSIGFBP-rP1 expression is negatively correlated with its methylation status in colorectal cancer. DNA methylation is one of the mechanisms regulating the expression of IGFBP-rP1. Hypomethylation of IGFBP-rP1 gene with its overexpression plays an important role in the initiation and development of colorectal cancer.

Adult ; Aged ; Aged, 80 and over ; Azacitidine ; analogs & derivatives ; pharmacology ; Cell Line, Tumor ; Colorectal Neoplasms ; genetics ; CpG Islands ; physiology ; DNA Methylation ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Insulin-Like Growth Factor Binding Proteins ; genetics ; Male ; Middle Aged ; RNA, Messenger ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; trends ; Transcription, Genetic