Systemic Prophylactic Antibiotics for the Modified Introducer Method for Percutaneous Endoscopic Gastrostomy: A Prospective, Randomized, Double-Blind Study.

BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) is the most common method of enteral nutrition in patients who require long-term tube feeding. According to meta-analyses, administration of systemic prophylactic antibiotics for PEG reduces peristomal infection. However, with several recent developments in the procedure and instruments, the risk of infection might have been reduced. The aim of this study was to evaluate the use of systemic antibiotic prophylaxis for a modified introducer method of PEG. METHODS: This prospective, randomized, double-blind trial assessed 278 patients undergoing PEG for inclusion. Ninety-one patients with an indication for PEG who gave informed consent to participate were randomized. Forty-six patients received prophylactic ampicillin and 45 patients received a placebo. A modified introducer method of PEG using a Seldinger PEG kit was performed. The primary outcome was the occurrence of clinically evident wound infection within 3 days after PEG. RESULTS: Wound infection within 3 days was observed in none in the prophylaxis group and in 1 patient in the control group (P=0.4945). There was no significant difference between 2 groups in the other parameters, including peristomal infection within 7 days, overall infection, white blood cell counts, C-reactive protein level, and successive rate of finishing antibiotics. CONCLUSIONS: For wound infection within 3 days, noninferiority of the placebo group to the antibiotics group was preliminarily suggested with our criteria, but not for peristomal infection within 7 days. More strict criteria for noninferiority should be examined in a further large sample study.

Hepatic portal venous gas in pancreatic solitary metastasis from an esophageal squamous cell carcinoma.

BACKGROUND: Hepatic portal venous gas (HPVG) is a rare entity commonly associated with intestinal necrosis and fatal outcome, and various underlying diseases have been reported. Pancreatic solitary metastasis without local extension is also rare in esophageal squamous cell carcinoma. METHODS: This report describes an interesting and unusual case of HPVG arising from pancreatic tumor. Autopsy revealed pathogenesis of HPVG and synchronous tumors of the esophagus and pancreas. RESULTS: A 73-year-old man developed synchronous double tumor in the esophagus and pancreas several months before acute abdomen and his death, which were generated by HPVG. Autopsy revealed that HPVG was caused by gastric wall infarction owing to expansion of an isolated pancreatic metastasis from esophageal squamous cell carcinoma. CONCLUSIONS: This is the first case of HPVG that was derived from pancreatic tumor infiltration. If he had been diagnosed with solitary pancreatic metastasis from esophageal squamous cell carcinoma in the first time, he might have an option for chemotherapy, which could let him live longer.

Granulocyte Colony-stimulating Factor- and Interleukin-6-producing Large-cell Carcinoma of the Lung with Sarcomatoid Changes Suggestive of Epithelial-mesenchymal Transition: An Autopsy Case Report.

A rare case of lung cancer with the simultaneous production of granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6) is reported. A 79-year-old man was admitted to our hospital due to cachectic symptoms and an increased inflammatory response. Laboratory tests and imaging studies suggested metastatic lung cancer with high serum levels of G-CSF and IL-6. He died of progressive disease, and an autopsy showed that the lung tumor had positive protein expression of both cytokines and a solid growth of large-cell carcinoma with sarcomatoid changes, possibly resulting from the epithelial-mesenchymal transition mediated by IL-6 and leading to widespread metastases.

Cytoplasmic RASSF2A is a proapoptotic mediator whose expression is epigenetically silenced in gastric cancer.

Gastric cancer cells often show altered Ras signaling, though the underlying molecular mechanism is not fully understood. We examined the expression profile of eight ras-association domain family (RASSF) genes plus MST1/2 and found that RASSF2A is the most frequently downregulated in gastric cancer. RASSF2A was completely silenced in 6 of 10 gastric cancer cell lines as a result of promoter methylation, and expression was restored by treating the cells with 5-aza-2'-deoxycytidine. Introduction of RASSF2A into non-expressing cell lines suppressed colony formation and induced apoptosis. These effects were associated with the cytoplasmic localization of RASSF2A and morphological changes to the cells. Complementary DNA microarray analysis revealed that RASSF2A suppresses the expression of inflammatory cytokines, which may in turn suppress angiogenesis and invasion. In primary gastric cancers, aberrant methylation of RASSF2A was detected in 23 of 78 (29.5%) cases, and methylation correlated significantly with an absence of the lymphatic invasion, absence of venous invasion, absence of lymph node metastasis, less advanced stages, Epstein-Barr virus, absence of p53 mutations and the presence of the CpG island methylator phenotype-high. These results suggest that epigenetic inactivation of RASSF2A is required for tumorigenesis in a subset of gastric cancers.

Epigenetic inactivation of RASSF2 in oral squamous cell carcinoma.

Genetic and epigenetic alterations in tumor-suppressor genes play important roles in human neoplasia. Ras signaling is often activated in oral squamous cell carcinoma (OSCC), although Ras mutations are rarely detected in Japanese OSCC patients, and the mechanisms underlying the gene's activation remain unclear. Here, we examined the expression of Ras association family (RASSF) genes in a panel of OSCC cell lines and found that RASSF2 is often downregulated by DNA methylation in OSCC cells. In addition, aberrant methylation of RASSF2 was detected in 12 of 46 (26%) primary OSCC, and 18 (39%) of those OSCC showed methylation of at least one RASSF gene. Ectopic expression of RASSF2 in OSCC cells suppressed cell growth and induced apoptosis. A RASSF2 deletion mutant lacking the Ras-association domain, which was therefore unable to interact with Ras, exhibited less pro-apoptotic activity than the full-length protein, indicating that the pro-apoptotic activity of RASSF2 is related to its association with Ras. Genomic screening of genes regulated by RASSF2 showed that genes involved in immune responses, angiogenesis, and metastasis are suppressed by RASSF2. Our results suggest that epigenetic inactivation of RASSF2 plays an important role in OSCC tumorigenesis, and that RASSF2 may be a useful molecular target for the diagnosis and treatment of OSCC.

Comparative genome analysis identifies the vitamin D receptor gene as a direct target of p53-mediated transcriptional activation.

p53 is the most frequently mutated tumor suppressor gene in human neoplasia and encodes a transcriptional coactivator. Identification of p53 target genes is therefore key to understanding the role of p53 in tumorigenesis. To identify novel p53 target genes, we first used a comparative genomics approach to identify p53 binding sequences conserved in the human and mouse genome. We hypothesized that potential p53 binding sequences that are conserved are more likely to be functional. Using stringent filtering procedures, 32 genes were newly identified as putative p53 targets, and their responsiveness to p53 in human cancer cells was confirmed by reverse transcription-PCR and real-time PCR. Among them, we focused on the vitamin D receptor (VDR) gene because vitamin D3 has recently been used for chemoprevention of human tumors. VDR is induced by p53 as well as several other p53 family members, and analysis of chromatin immunoprecipitation showed that p53 protein binds to conserved intronic sequences of the VDR gene in vivo. Introduction of VDR into cells resulted in induction of several genes known to be p53 targets and suppression of colorectal cancer cell growth. In addition, p53 induced VDR target genes in a vitamin D3-dependent manner. Our in silico approach is a powerful method for identification of functional p53 binding sites and p53 target genes that are conserved among humans and other organisms and for further understanding the function of p53 in tumorigenesis.

Oncocytic Type Intraductal Papillary Mucinous Neoplasm of the Pancreas with Unusually Low Mucin Production Mimicking Intraductal Tubulopapillary Neoplasm: A Report of a Case Diagnosed by a Preoperative Endoscopic Biopsy.

We herein report the case of a 78-year-old woman with an intraductal tumor with scant mucin production in a moderately dilated main pancreatic duct that resembled an intraductal tubulopapillary neoplasm (ITPN) on imaging. An endoscopic transpapillary forceps biopsy enabled an accurate preoperative diagnosis of the tumor as an oncocytic type intraductal papillary mucinous neoplasm (IPMN) of the pancreas microscopically showing papillary growth consisting of oncocytic cells with a typical mucin expression profile, although with few intraepithelial lumina containing mucin. This is the first case of an oncocytic type IPMN mimicking an ITPN that was able to be diagnosed preoperatively.

Aberrant methylation and silencing of the BNIP3 gene in colorectal and gastric cancer.

BNIP3 protein is a proapoptotic member of the Bcl-2 family that is expressed in hypoxic regions of tumors. To examine its role in the progression of gastrointestinal cancer, we examined the expression and DNA methylation status of BNIP3 gene in a panel of colorectal and gastric cancer cell lines. BNIP3 was not expressed in 14 of the 24 cell lines tested, and its absence was not caused by gene mutation or by altered expression of hypoxia inducible factor-1, a key transcription factor that regulates BNIP3 expression. On the other hand, methylation of the 5' CpG island of BNIP3 was closely correlated with silencing the gene. Moreover, treating methylated cells with the methyltransferase inhibitor 5-aza-2'-deoxycytidine restored hypoxia-induced expression of BNIP3 mRNA and protein, which in turn led to cell death. Aberrant methylation of BNIP3 was also detected in 66% of primary colorectal and 49% of primary gastric cancers, but not in normal tissue samples collected from areas adjacent to the tumors. Apparently, epigenetic alteration of BNIP3 is a frequent and cancer-specific event, which suggests that inactivation of BNIP3 likely plays a key role in the progression of some gastrointestinal cancers and that it may be a useful molecular target for therapy.

Epigenetic inactivation of class II transactivator (CIITA) is associated with the absence of interferon-gamma-induced HLA-DR expression in colorectal and gastric cancer cells.

Tightly regulated at the level of transcription, expression of MHC class II molecules varies significantly among gastrointestinal cancers. High levels of MHC class II expression are often associated with a better prognosis, which is indicative of the involvement of CD4+ lymphocytes in tumor suppression, but the molecular mechanism by which MHC class II expression is regulated remains unclear. In the present study, we investigated the expression of one inducible MHC class II molecule, HLA-DR, and its coactivators in a panel of colorectal and gastric cancer cell lines. Interferon-gamma induced expression of HLA-DR in 14 of 20 cell lines tested; the remaining six cell lines did not express HLA-DR. Analysis of the expression of transcription factors and coactivators associated with HLA-DR revealed that the loss of CIITA expression was closely associated with the absence of HLA-DR induction. Moreover, DNA methylation of the 5' CpG island of CIITA-PIV was detected in all cancer cells that lacked CIITA. The methylation and resultant silencing of CIITA-PIV depended on the activities of two DNA methyltransferases, DNMT1 and DNMT3B, and their genetic inactivation restored CIITA-PIV expression. It thus appears that CIITA methylation is a key mechanism that enables some gastrointestinal cancer cells to escape immune surveillance.

Small interfering RNA-induced CHFR silencing sensitizes oral squamous cell cancer cells to microtubule inhibitors.

Alterations in the function of cell cycle checkpoints are frequently detected in oral squamous cell carcinomas (OSCCs), and are often associated with the sensitivity of the cancer cells to chemotherapeutic drugs. Recently, a mitotic checkpoint gene, Chfr, was shown to be inactivated by promoter methylation and point mutations in various human tumors. Here we show that the absence of its product, CHFR, is associated with mitotic checkpoint dysfunction, and that cancer cells lacking CHFR are sensitive to microtubule inhibitors. Checkpoint impairment appears to be caused by a prophase defect in this case, as OSCC cells lacking CHFR showed phosphorylation of histone H3 on Ser10 and translocation of cyclin B1 to the nucleus. When CHFR-deficient OSCC cells were treated with a microtubule inhibitor (docetaxel or paclitaxel), significant numbers of apoptotic cells were observed. Moreover, disruption of CHFR using small interfering RNA (siRNA) impaired the mitotic checkpoint, thereby reducing the ability of OSCC cells to arrest at G2/M phase and making them more sensitive to microtubule inhibitors. Our results suggest that CHFR could be a useful molecular target for chemotherapy.

Upregulation of BNIP3 by 5-aza-2'-deoxycytidine sensitizes pancreatic cancer cells to hypoxia-mediated cell death.

BACKGROUND: Pancreatic cancer cells often show resistance to hypoxia-mediated apoptosis, but the molecular mechanism underlying that resistance remains unknown. The purpose of the present study, therefore, was to examine the role of epigenetic gene alteration in the resistance to hypoxia-mediated apoptosis among pancreatic cancer cells. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to examine the expression of five genes associated with hypoxia-mediated apoptosis (PUMA, Caspase-8 [CASP8], APAF-1, BNIP3, and BNIP3L) in a panel of pancreatic cancer cell lines. Protein expression was examined by Western blot analysis, using lysates from cells incubated under normoxic or hypoxic conditions. The methylation status of the genes was determined using bisulfite-PCR and sequencing. The percentages of cells that were apoptotic were determined using flow cytometry. RESULTS: Under normoxic conditions, the expression of the BNIP3 gene varied among the 12 pancreatic cancer cell lines tested, with 50% of them showing no BNIP3 expression at all, whereas expression of the other four genes was readily detected in all 12 cell lines. DNA methylation of BNIP3's CpG island in the region around the transcription start site of the gene was closely associated with its silencing. The expression of BNIP3 was restored by the methyltransferase inhibitor 5-aza-deoxycytidine (5-aza-dC), as was the hypoxia-mediated pancreatic cancer cell death. CONCLUSIONS: BNIP3 expression is silenced in some pancreatic cancer cells by the methylation of its CpG island. Demethylation of BNIP3, using a methyltransferase inhibitor, restores the gene's expression and induces hypoxia-mediated cell death. BNIP3 may thus be a useful target for new therapies aimed at treating pancreatic cancer.

Identification of HRK as a target of epigenetic inactivation in colorectal and gastric cancer.

PURPOSE: Aberrant methylation of CpG islands can be a good molecular marker for identifying genes inactivated in cancer. We found the proapoptotic gene HRK to be a target for hypermethylation in human cancers and examined the role of such methylation in silencing the gene's expression. EXPERIMENTAL DESIGN: Methylation of HRK was evaluated by bisulfite-PCR and bisulfite sequencing in a group of colorectal and gastric cancer cell lines and primary cancers. Gene expression and histone acetylation were examined by reverse transcription-PCR and chromatin immunoprecipitation analyses, respectively. Apoptosis of cancer cells after treatment with a DNA methyltransferase inhibitor and/or histone deacetylase inhibitor was examined with fluorescence-activated cell-sorting analysis. RESULTS: The region around the HRK transcription start site was methylated in 36% of colorectal and 32% of gastric cancer cell lines and was closely associated with loss of expression in those cell types. HRK expression was restored by treatment with a methyltransferase inhibitor, 5-aza-deoxycytidine, and enhanced further by addition of histone deacetylase inhibitor trichostatin A or depsipeptide. Such restoration of HRK expression was well correlated with induction of apoptosis and enhancement of Adriamycin-induced apoptosis. Expression of other proapoptotic genes, including BAX, BAD, BID, and PUMA, was unaffected by treatment with 5-aza-deoxycytidine. Aberrant methylation of HRK was also frequently detected in primary colorectal cancers that showed methylation of multiple genes, including p16INK4A and hMLH1, and was associated with wild-type p53. CONCLUSION: HRK methylation can be a useful molecular target for cancer therapy in a subset of colorectal and gastric cancers.

Anaplastic Carcinoma Possibly Arising from a Heterotopic Pancreas.

Anaplastic carcinoma is a rare pancreatic cancer, and the malignant transformation of a heterotopic pancreas is also rare. We herein report a case of an elderly woman with a mass of unknown origin in the abdominal cavity. Computed tomography identified the extent of the tumor but not the organ of origin. The abdominal tumor eventually metastasized to the liver and lung. An autopsy and immunohistochemical examination revealed an anaplastic carcinoma possibly originating in an ectopic pancreas.

Carcinoma of duodenum arising from Brunner's gland.

Primary carcinoma of the duodenum is a rare lesion. In conjunction with the widespread use of panendoscopy, reported cases of carcinoma of the duodenum have recently increased. Although benign hyperplasia of Brunner's gland is well documented, duodenal carcinoma originating in Brunner's gland is extremely rare, and, consequently, there is little data on the morphological or histochemical characteristics. We report here a case of early duodenal carcinoma arising from Brunner's gland, whose origin was proven by mucin immunohistochemistry.

Identification of DFNA5 as a target of epigenetic inactivation in gastric cancer.

Epigenetic gene inactivation plays a key role in the development of various types of cancer. Using methylated CpG island amplification coupled with representational difference analysis to identify genes inactivated by DNA methylation in gastric cancer, we identified seven DNA fragments corresponding to the 5' CpG islands of the affected genes. One of the clones recovered was identical to the 5' flanking region of DFNA5, a gene previously shown to be associated with deafness and induced by DNA damage. Further analysis revealed that DFNA5 is expressed in normal tissues but is down-regulated in gastric cancer cell lines due to methylation of the region around its transcription start site. Treating gastric cancer cells that lacked DFNA5 expression with a methyltransferase inhibitor, 5-aza-2'-deoxycytidine, restored the gene's expression. Methylation of DFNA5 was detected in 50% of primary gastric tumors, and was correlated with positivity for Epstein-Barr virus and the absence of metastasis. Moreover, introduction of exogenous DFNA5 into silenced cells suppressed colony formation. Taken together, these data suggest that the silencing of DFNA5 occurs frequently in gastric cancer and may play a key role in development and progression of the disease.

Genetic, epigenetic, and clinicopathologic features of gastric carcinomas with the CpG island methylator phenotype and an association with Epstein-Barr virus.

BACKGROUND: The CpG island methylator phenotype (CIMP), which is characterized by simultaneous methylation of the CpG islands of multiple genes, has been recognized as one of the important mechanisms in gastrointestinal carcinogenesis. METHODS: Methylation of the 5 methylated-in-tumors (MINT) loci and 12 tumor-related genes in 78 primary gastric carcinomas was examined using combined bisulfite-restriction analysis. Epstein-Barr virus (EBV)-associated gastric tumors were detected using real-time polymerase chain reaction analysis followed by an evaluation of the correlations between CIMP status, EBV-association, and genetic alteration of p53 and K-ras. The authors compared the clinicopathologic features of gastric carcinomas that had high CIMP methylation (CIMP-H) with tumors that had low CIMP methylation (CIMP-L) or negative CIMP methylation (CIMP-N). RESULTS: The methylation profiles of 12 genes showed nonrandom methylation, supporting the presence of CIMP in gastric carcinoma. No p53 mutations were detected among CIMP-H tumors, and no EBV association was detected in tumors that showed mutation of p53 and K-ras. In a multiple logistic regression model with CIMP-H as the dependent variable, proximal location (P = .011), diffuse type (P = .019), and less advanced pathologic TNM status (P = .043) contributed significantly to CIMP-H. Patients who had CIMP-N gastric tumors had a significantly worse survival than patients who had CIMP-H tumors (P = .004) or CIMP-L tumors (P = .012). EBV-associated tumors were associated strongly with CIMP-H, hypermethylation of tumor-related genes, and no p53 or K-ras mutation. CONCLUSIONS: CIMP status appeared to be associated with distinct genetic, epigenetic, and clinicopathologic features in gastric carcinomas. The finding that gastric carcinomas arose through different molecular pathways may affect not only tumor characteristics but also patient prognosis.

The Ras effector RASSF2 is a novel tumor-suppressor gene in human colorectal cancer.

BACKGROUND & AIMS: Activation of Ras signaling is a hallmark of colorectal cancer (CRC), but the roles of negative regulators of Ras are not fully understood. Our aim was to address that question by surveying genetic and epigenetic alterations of Ras-Ras effector genes in CRC cells. METHODS: The expression and methylation status of 6 RASSF family genes were examined using RT-PCR and bisulfite PCR in CRC cell lines and in primary CRCs and colorectal adenomas. Colony formation assays and flow cytometry were used to assess the tumor suppressor activities of RASSF1 and RASSF2. Immunofluorescence microscopy was used to determine the effect of altered RASSF2 expression on cell morphology. Mutations of K- ras , BRAF, and p53 were identified using single-strand conformation analysis and direct sequencing. RESULTS: Aberrant methylation and histone deacetylation of RASSF2 was associated with the gene's silencing in CRC. The activities of RASSF2, which were distinct from those of RASSF1, included induction of morphologic changes and apoptosis; moreover, its ability to prevent cell transformation suggests that RASSF2 acts as a tumor suppressor in CRC. Primary CRCs that showed K- ras /BRAF mutations also frequently showed RASSF2 methylation, and inactivation of RASSF2 enhanced K- ras -induced oncogenic transformation. RASSF2 methylation was also frequently identified in colorectal adenomas. CONCLUSIONS: RASSF2 is a novel tumor suppressor gene that regulates Ras signaling and plays a pivotal role in the early stages of colorectal tumorigenesis.

Aberrant methylation and histone deacetylation associated with silencing of SLC5A8 in gastric cancer.

Aberrant methylation of a sodium co-transporter, solute carrier family 5 member 8 gene (SLC5A8), has been detected in a subset of colorectal cancers, suggesting SLC5A8 may also serve as a tumor suppressor. To further investigate the role of epigenetic inactivation of SLC5A8 expression in gastric cancer, we determined the methylation status of the SLC5A8 5' CpG island (CGI) in a panel of gastric cancer cell lines and primary gastric cancers. We detected methylation of the 5'CGI in ten of twelve gastric cancer cell lines, and five of those showed dense methylation, which correlated with the absence of SLC5A8 transcription. Aberrant methylation of SLC5A8 was also detected in 23 of 71 (30%) primary gastric cancers, indicating that epigenetic inactivation of SLC5A8 is not a cell-line-specific phenomenon. SLC5A8 expression was restored in methylated cell lines by treatment with 5-aza-2'-deoxycytidine, a methyltransferase inhibitor. In addition, chromatin immunoprecipitation assays showed that acetylation of histone H3 in the 5' region of the gene correlated directly with SLC5A8 expression and inversely with DNA methylation. It thus appears that aberrant methylation of its 5'CGI and histone deacetylation play key roles in silencing SLC5A8 expression in gastric cancers.