Case report of cryptogenic multifocal ulcerous stenosing enteritis (CMUSE): a rare disease may contribute to endoscopy-capsule retention in the small intestine.

BACKGROUND: CMUSE is a rare disease whose diagnosis remains difficult because the lesion is confined to the small bowel. CASE PRESENTATION: Here, we present a case of 43-year-old female patient suffered chronic abdominal pain for 20 years, and finally diagnosed with CMUSE. Capsule endoscopy was performed when general endoscopic investigation failed to find the lesion, but the capsule was stranded in the small intestine. Moreover, capsule retention results in acute intestinal obstruction. Thus, surgery was performed and CMUSE was confirmed. The patient was recovered after partial small intestine resection. CONCLUSIONS: Capsule retention occurred in nearly 60% of patients with CMUSE. Capsule endoscopy should be avoided when the patient is suspected of CMUSE, especially with severe anemia and radiologic finding in the ileum.

Assessing the potential value of long interspersed element-1 hypomethylation in colorectal cancer: evidence from retrospective studies.

BACKGROUND AND AIMS: Long interspersed element-1 (LINE-1) hypomethylation may play an important role in colorectal cancer (CRC). Studies were identified that investigated LINE-1 methylation levels in CRC compared with normal controls. METHODS: The random-effects model was used to estimate standardized mean difference with 95% confidence intervals according to the heterogeneity between the studies. We explored the relationship between LINE-1 hypomethylation and microsatellite instability (MSI) status, clinical features, and molecular features in CRC patients using a fixed-effects model. RESULTS: A total of 7396 CRC patients were included in the meta-analysis. LINE-1 methylation was significantly lower in CRC patients than in controls (P=0.000). Mean LINE-1 methylation was significantly lower in non-MSI-high than in MSI-high tumors (P=0.000). LINE-1 hypomethylation was found more frequently in patients with a family history compared with those without family history (P=0.002). Patients with left colon cancer had lower LINE-1 methylation than those with right colon cancer (P=0.001). LINE-1 methylation was not associated with body mass index or patient sex. LINE-1 hypomethylation was found in p21 lost tumors (P=0.000). LINE-1 methylation levels were not associated with KRAS or PIK3CA-mutation status. CONCLUSION: LINE-1 hypomethylation is a potential biomarker for risk of CRC and associated with various clinical and molecular features of CRC.

Folic acid prevents the initial occurrence of sporadic colorectal adenoma in Chinese older than 50 years of age: a randomized clinical trial.

Colorectal adenoma (CRA) is the precursor lesion of colorectal cancer (CRC). Several agents have been shown to be effective in the chemoprevention of CRA recurrence, but there has been little research on its primary prevention. Participants older than 50 years with no adenomas were recruited for our study and randomized to receive either 1 mg/day folic acid supplement or treatment without folic acid. After 3 years of follow-up, plasma folate and colonoscopy were evaluated. Seven hundred ninety-one participants (91.98%) completed the study. CRA occurred in 64 (14.88%) participants in the folic acid group and 132 (30.70%) in the control group [unadjusted risk ratio (RR), 0.49; 95% confidence interval (CI), 0.37-0.63; P < 0.01]; left-sided adenoma (unadjusted RR, 0.54; 95% CI, 0.38-0.76; P = 0.001) and advanced CRA (unadjusted RR, 0.36; 95% CI, 0.16-0.81; P = 0.01) were most common. There was no significance difference in the occurrence of three or more adenomas (unadjusted RR, 0.70; 95% CI, 0.36-1.77; P = 0.38) or right-sided adenoma (unadjusted RR, 0.55; 95% CI, 0.30-1.00; P = 0.07) between the two groups. Participants with low plasma folate may have a high risk of CRA. In conclusion, primary prevention with 1 mg/day folic acid supplementation could reduce the incidence of CRA, especially left-sided and advanced disease in those with no previous adenomas. People with differing baseline plasma folate levels should be given individualized treatment. Those with low plasma folate should be encouraged to take adequate supplements; plasma folate should be elevated to an effective therapeutic level, which may reduce the incidence of CRA.

Constitutive activation of STAT3 is predictive of poor prognosis in human gastric cancer.

Abnormalities in signal transducer and activator of transcription (STAT) signaling, especially STAT3 and STAT5, are involved in the oncogenesis of several human cancers, including gastric cancer (GC). However, the downstream targets of STAT3 and STAT5 are not fully identified, and the precise roles and the prognostic value of STAT3 and STAT5 in GC have not been fully characterized. In this study, we used ChIP-on-chip to identify STAT3 and STAT5 target genes on a whole genome scale in AGS cells, a human GC cell line. A total of 2,514 and 1,314 genes were identified as STAT3 and STAT5 target genes, which were mainly related to cell growth, metabolism, differentiation, adhesion, immune response, and stress response. Furthermore, we depleted STAT3 and STAT5 with a small interfering RNA, respectively. Our results demonstrate that STAT3, but not STAT5, is involved in GC cell growth and cell cycle progression through regulation of gene expression, such as Bcl-2, p16(ink4a) and p21(waf1/cip1). Moreover, expression of pSTAT3(Tyr705) correlates with TNM stage, differentiation and survival, and is a significant prognostic factor in GC. Therefore, our findings provide novel evidence that STAT3 may be a potential therapeutic target for GC treatment and pSTAT3(Tyr705) expression can predict prognosis in GC.

Trichostatin A, a histone deacetylase inhibitor, suppresses JAK2/STAT3 signaling via inducing the promoter-associated histone acetylation of SOCS1 and SOCS3 in human colorectal cancer cells.

Aberrant janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling is involved in the oncogenesis of several cancers. Suppressors of cytokine signaling (SOCS) genes and SH2-containing protein tyrosine phosphatase 1 (SHP1) proteins, which are negative regulators of JAK/STAT signaling, have been reported to have tumor suppressor functions. However, in colorectal cancer (CRC) cells, the mechanisms that regulate SOCS and SHP1 genes, and the cause of abnormalities in the JAK/STAT signaling pathway, remain largely unknown. The present study shows that trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, leads to the hyperacetylation of histones associated with the SOCS1 and SOCS3 promoters, but not the SHP1 promoter in CRC cells. This indicates that histone modifications are involved in the regulation of SOCS1 and SOCS3. Moreover, upregulation of SOCS1 and SOCS3 expression was achieved using TSA, which also significantly downregulated JAK2/STAT3 signaling in CRC cells. We also demonstrate that TSA suppresses the growth of CRC cells, and induces G1 cell cycle arrest and apoptosis through the regulation of downstream targets of JAK2/STAT3 signaling, including Bcl-2, survivin and p16(ink4a) . Therefore, our data demonstrate that TSA may induce SOCS1 and SOCS3 expression by inducing histone modifications and consequently inhibits JAK2/STAT3 signaling in CRC cells. These results also establish a mechanistic link between the inhibition of JAK2/STAT3 signaling and the anticancer action of TSA in CRC cells.

TRAPPC4-ERK2 interaction activates ERK1/2, modulates its nuclear localization and regulates proliferation and apoptosis of colorectal cancer cells.

The trafficking protein particle complex 4 (TRAPPC4) is implicated in vesicle-mediated transport, but its association with disease has rarely been reported. We explored its potential interaction with ERK2, part of the ERK1/2 complex in the Extracellular Signal-regulated Kinase/ Mitogen-activated Protein Kinase (ERK-MAPK) pathway, by a yeast two-hybrid screen and confirmed by co-immunoprecipitation (Co-IP) and glutathione S-transferase (GST) pull-down. Further investigation found that when TRAPPC4 was depleted, activated ERK1/2 specifically decreased in the nucleus, which was accompanied with cell growth suppression and apoptosis in colorectal cancer (CRC) cells. Overexpression of TRAPPC4 promoted cell viability and caused activated ERK1/2 to increase overall, but especially in the nucleus. TRAPPC4 was expressed more highly in the nucleus of CRC cells than in normal colonic epithelium or adenoma which corresponded with nuclear staining of pERK1/2. We demonstrate here that TRAPPC4 may regulate cell proliferation and apoptosis in CRC by interaction with ERK2 and subsequently phosphorylating ERK1/2 as well as modulating the subcellular location of pERK1/2 to activate the relevant signaling pathway.

MicroRNA 345, a methylation-sensitive microRNA is involved in cell proliferation and invasion in human colorectal cancer.

Aberrant methylation has been shown to trigger the inactivation of tumor suppressor genes during tumorigenesis. MicroRNAs (miRNAs) have been found deregulated in human colorectal cancer (CRC), and some of them may function as tumor suppressor genes. Here, we investigated CpG island promoter hypermethylation as a potential mechanism underlying miRNA disruption and identifed methylation-sensitive miRNAs that might repress CRC development. We compared differential expression of miRNAs after 5-aza-2'-deoxycitidine (5-aza-dC) treatment using microarrays. DNA methylation status of the candidate miRNA was analyzed. The candidate miRNA was transfected into CRC cells and growth-suppressive mechanisms were explored. Luciferase reporter assay and western blot were used to identify the target genes of the candidate miRNA. The expression of mir-345 was significantly increased after 5-aza-dC treatment. DNA methylation analyses of mir-345 showed high methylation levels in tumor versus normal tissues. Expression of mir-345 was significantly down-regulated in 51.6% of CRC tissues compared with corresponding non-cancerous tissues. Low expression of mir-345 was associated with lymph node metastasis and worse histological type. Increased mir-345 function was sufficient to suppress colon cancer cell proliferation and invasiveness in vitro. Furthermore, we identified BCL2-associated athanogene 3 (BAG3), an anti-apoptosis protein, to be a target of mir-345. These results suggested as a methylation-sensitive miRNA in CRC, mir-345 may play an important role of antineoplastic as a growth inhibitor in the development of CRC.

XRCC1 downregulated through promoter hypermethylation is involved in human gastric carcinogenesis.

OBJECTIVE: To analyze the expression and aberrant methylation of X-ray repair cross-complementing gene 1 (XRCC1) in gastric carcinogenesis, and identify the molecular mechanism of gastric carcinogenesis. METHODS: The method based on methyl binding domain protein (MBD) immuno-precipitation and promoter microarray was employed to screen the gastric cancer-related methylation-sensitive gene. An immunohistochemistry assay was applied to detect the protein expression of XRCC1 in the multistep progression of gastric carcinogenesis. The mRNA expression of XRCC1 was determined by real-time PCR in tumor tissues and their corresponding non-tumorous tissues. The methylation status and Arg194Trp and Arg399Gln polymorphisms of XRCC1 in gastric cancer and gastritis tissues were analyzed by methylation-specific PCR, bisulfite genomic sequencing and direct DNA sequencing, respectively. RESULTS: Promoter microarray screening and identification suggested that XRCC1 was a methylation-sensitive gene. Immunochemistry results showed that XRCC1 protein expression gradually decreased with progression of gastric mucosal lesions (P < 0.05). The positive rate of XRCC1 in patients with well/moderately differentiated gastric cancer was significantly higher than patients with poorly differentiated gastric cancer (P < 0.05). The mRNA expression of XRCC1 in gastric cancer tissues was significantly lower than that in the non-tumorous tissues (P < 0.05). Meanwhile, XRCC1 methylation in gastric cancer tissues was more frequent than that in the gastritis tissues (P < 0.05), and the downregulation of XRCC1 expression was relevant to methylation (P < 0.05). CONCLUSION: The expression of XRCC1 is downregulated in gastric carcinogenesis, and promoter hypermethylation may be one of the mechanisms contributing to its downregulation.

Meta-analysis: perioperative regional liver chemotherapy for improving survival and preventing liver metastases in patients with colorectal carcinoma.

OBJECTIVE: To evaluate the effect of prophylactic regional liver chemotherapy during the perioperative period on improving survival and preventing liver metastases in patients with colorectal cancer (CRC). METHODS: A comprehensive retrieval of the relevant literature was performed by searching major biomedical database, mainly from Medline and Embase. Studies reported in the selected literature were categorized into two subgroups according to the type of therapy: a perioperative hepatic artery infusion subgroup and a perioperative portal vein infusion subgroup. Mortality and liver metastasis were analyzed using a fixed-effects model. Statistical analysis was performed using Review Manager software. RESULTS: The results of this meta-analysis illustrated that survival and the rate of liver metastasis in patients receiving perioperative hepatic artery infusion (HAI) chemotherapy were significantly better than for those receiving surgery alone (pooled relative risk 0.46 [95% CI: 0.31-0.69] and 0.44 [95% CI: 0.28-0.68], respectively, P= 0.0002), while survival and the rate of liver metastasis in patients receiving perioperative portal vein infusion (PVI) chemotherapy were not significantly different from those receiving surgery alone (pooled relative risk 0.98 [95% CI: 0.89-1.09], P= 0.73 and 0.86 [95% CI: 0.72-1.02], respectively. P= 0.08). CONCLUSION: As a method of regional liver chemotherapy, HAI might be able to improve survival and reduce the rate of liver metastasis in patients with advanced CRC.

MicroRNA regulatory network in human colorectal cancer.

Epigenetic modifications include DNA methylation, histone modifications, and noncoding RNAs containing microRNAs (miRNA). miRNAs are small noncoding RNAs that are 21 to 25 nt in length; they downregulate gene expression during cell development, cell proliferation, cell differentiation, and apoptosis. They play a critical role in human carcinogenesis. Presently, evidences show that miRNAs participate as oncogenic miRNAs or tumor suppressors in the developmental and physiological processes of human colorectal cancer (CRC). Disturbed miRNA expression may be attributable to a mechanism involving multiple factors. In this review, we focus on the colorectal miRNA expression profile and further discuss the miRNA regulatory network involved in the tumorigenesis of human CRC. We, thus, hope to open up new avenues for anticancer therapy based on the epigenetic regulation of miRNA.

[Recent progress on miRNAs in the pathogenesis of colon cancer].

microRNAs (miRNAs) are endogenous, small noncoding RNA molecules discovered in animals, plants and viruses. They play a critical role in developmental and physiological processes and are implicated in the pathogenesis of many human cancers. Presently, human cancer, including colorectal cancer, is recognized as both a genetic and epigenetic disease. Changes induced by miRNAs are considered as epigenetic changes. Experiments were largely performed to analyze the colorectal microRNAome and bio-networking involving miRNAs. This review focuses on recent advances in colorectal miRNA expression profiles. Further, we discuss the regulatory network of miRNAs in the initiation and carcinogenesis of colon cancer in order to open up an avenue of anticancer therapy based on the epigenetic regulation by miRNAs.