Fetal cardiac capillary hemangioma resulting in tachyarrhythmia

We present the case of a fetus with cardiac capillary hemangioma in the right atrial cavity. The tumor showed dramatic growth between the 28^th and 32^nd week of gestation and resulted in tachyarrhythmia. The patient was born at the 33 weeks of gestation weighing 2430 g via urgent cesarean section because the rapidly growing cardiac tumor caused incessant tachyarrhythmia, pericardial effusion, and fetal circulatory incompetence. Coronary angiography revealed that the right coronary artery drained into the tumor. Due to hemodynamic deterioration, the patient underwent subtotal resection of the tumor on the 2^nd day after birth. Histopathological examination revealed an undifferentiated capillary hemangioma. The patient was discharged at the age of 86 days, as the tachyarrhythmia and hemodynamic incompetence had subsided; however, bradycardia and intermittent atrioventricular conduction disturbance gradually developed. Capillary hemangioma, a rare primary cardiac space-occupying tumor in children, can invade the conduction system.

Myxoid type and non-myxoid type of intimal sarcoma in large vessels and heart: review of histological and genetic profiles of 20 cases

Intimal sarcoma is one of the most common and well-known primary malignant neoplasms of the aorta and heart. The authors reviewed cases of intimal sarcoma from histological, immunohistochemical and genetic perspectives. Twenty cases of intimal sarcoma were retrieved. Immunohistochemistry and FISH of MDM2 and PDGFRA genes were performed. All 20 tumours were composed of spindle-shaped, stellate, oval or polygonal tumour cells with irregular hyperchromatic nuclei arranged in a haphazard pattern, accompanied by nuclear pleomorphism and frequent mitotic figures. Other histological findings were as follows: abnormal mitosis in 10 cases (50%), necrosis in 15 cases (75%), myxoid stroma in 12 cases (60%), cartilaginous formation in 1 case (5%), haemorrhage in 12 cases (60%) and fibrinous deposition in 14 cases (70%). The tumours were positive for MDM2 in 16 cases (80%), ERG in 4 cases (20%), alpha-smooth muscle actin in 6 cases (30%), desmin in 5 cases (25%) and AE1/AE3 in 4 cases (20%). Immunohistochemical positivity was focal in each case. Loss of H3K27me3 expression was noted in 2 cases (10%). MDM2 and PDGFRA gene amplifications were detected in 11 cases (55%) and 1 case (5%), respectively. Fisher's exact test revealed a significant correlation between MDM2 gene amplification and myxoid stroma (p = 0.0194). No parameters showed any association with the anatomical location of the tumours. It was suggested that myxoid histology of intimal sarcoma may be associated with MDM2 gene amplification and that intimal sarcoma may be divided into myxoid and non-myxoid types.

A Rare Case of Pulmonary Tumor Thrombotic Microangiopathy Associated with Micropapillary Urothelial Carcinoma of the Urinary Bladder: An Autopsy Case

A 70-year-old woman was hospitalized with dyspnea. A transthoracic echocardiogram indicated an elevated systolic pulmonary artery pressure, and the cytology specimens obtained using a pulmonary artery catheter confirmed adenocarcinoma metastasis. Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) detected high-signal-intensity lesions in the urinary bladder. The patient died of respiratory failure and a postmortem examination was performed. Tumor cells in the bladder were immunohistochemically positive for GATA3, indicating micropapillary urothelial carcinoma, which is a rare variant of urothelial carcinoma and considered an adenocarcinoma subtype. This case is the first autopsy case of pulmonary tumor thrombotic microangiopathy (PTTM) associated with micropapillary urothelial carcinoma of the urinary bladder.

Morphological, immunohistochemical, and genomic analyses of papillary renal neoplasm with reverse polarity

Papillary renal neoplasm with reverse polarity (PRNRP) is a recently proposed entity of renal tumor. It shows a far better prognosis than papillary renal cell carcinoma (PRCC) and frequently has KRAS missense mutation. In this study, we compared 14 cases of PRNRP and 10 cases of PRCC type 1 (PRCC1) and type 2 (PRCC2) from clinical, morphological, immunohistochemical, and molecular biological perspectives. We subjected all PRNRP and PRCC cases to immunohistochemical analysis. Whole-exome sequencing using next-generation sequencing (NGS) was performed for six cases of PRNRP, three cases of PRCC1, and four cases of PRCC2. A search for KRAS gene mutation in the remaining eight cases of PRNRP was performed by polymerase chain reaction (PCR) sequencing. The results showed that all cases of PRNRP were pT1N0M0, none of which followed a course of recurrence or tumor-related death. Immunohistochemical analysis revealed diffuse staining of CK7, EMA, PAX8, and GATA3 but weak or negative staining of CD10, CD15, and AMACR in PRNRP. By NGS and PCR, KRAS missense mutation was detected in 11 of 14 PRNRP cases, although pathogenic KRAS mutation was not observed in PRCC1 and PRCC2. NGS analysis revealed less tumor mutation burden in PRNRP than in PRCC. PRNRP also showed no specific chromosomal copy number abnormalities, including gains of 7 and 17. In conclusion, we propose that PRNRP is a distinct condition from PRCC.

Laparoscopic high anterior resection for triple colorectal cancers with persistent ascending and descending mesocolons: A case report

Persistent mesocolon is an embryological anomaly of the colon resulting from failure of the primitive dorsal mesocolon to fuse with the parietal peritoneum. We herein present a case of laparoscopic high anterior resection for triple colorectal cancers with persistent ascending and descending mesocolons and a right-bound inferior mesenteric artery. Preoperative 3-D CT demonstrated that the sigmoid colon had shifted to the right abdomen and was located under the ascending colon. Moreover, the inferior mesenteric artery and vein traveled toward the right abdomen accompanied by the mesentery of the descending colon. Adhesiolysis between the ascending and sigmoid colon was initially performed, and the sigmoid colon was placed in its normal position. The inferior mesenteric artery was then divided with lymph node dissection using a medial approach, and high anterior resection was completed. An understanding of the anatomical characteristics of persistent mesocolon is important to ensure safe laparoscopic surgery.

A case of non-alcoholic steatohepatitis complicated with severe acute pancreatitis induced by decreased lipoprotein lipase and hepatic triglyceride lipase activity levels in a young Japanese woman

We report a case of non-alcoholic steatohepatitis complicated with acute pancreatitis induced by hypertriglyceridemia in a young Japanese woman. A precise examination of the lipid profile showed decreased lipoprotein lipase (LPL) and hepatic triglyceride lipase activity levels, while the LPL mass was at the minimum level of the normal range.

Stage IV gastric cancer successfully treated by multidisciplinary therapy including chemotherapy, immunotherapy, and surgery: a case report

BACKGROUND

The prognosis of stage IV gastric cancer (GC) still remains unfavorable. Multidisciplinary approaches should therefore be considered to improve the survival of patients with stage IV GC. We report here a case of primary GC with potentially unresectable metastasis, successfully treated by a multidisciplinary approach including chemotherapy, immunotherapy, and surgery.

CASE PRESENTATION

A 74-year-old man presented with multiple left neck masses. Abdominal computed tomography showed a thickened gastric wall and multiple lymphadenopathies including left supraclavicular lymph node. Gastroenterological endoscopy revealed tumor lesions in the gastric cardia. Tumor biopsy indicated a pathological diagnosis of poorly differentiated adenocarcinoma. Open left cervical lymph node biopsy showed histological features identical with the gastric tumor, indicating left clavicle lymph node metastasis of GC. After 2 years of chemo-immunotherapy with S-1/CDDP, paclitaxel, and cytokine-activated killer cells, lesions other than the stomach lesion had regressed to undetectable on imaging studies. The patient then underwent laparoscopy-assisted total gastrectomy with Roux-en-Y reconstruction followed by adjuvant chemo-immunotherapy with paclitaxel and S-1 for 1 year, and immunotherapy with tumor lysate-pulsed dendritic cell-activated killer cells for 5 years. The patient remained well after 5 years and 6 months of follow-up, with no signs of recurrence.

CONCLUSION

Therapeutic combinations including immunotherapy may thus allow surgery to be performed in patients previously considered unsuitable for surgical intervention, potentially leading to a clinical cure, as in the current case.

Drug-induced Liver Injury Associated with Mosapride Citrate: A Report of Two Cases

We herein report two cases of drug-induced liver injury (DILI) due to mosapride. Case 1: A 78-year-old man was admitted with elevated transaminase levels. The cessation of mosapride led to the improvement of elevated liver enzyme levels. Case 2: A 54-year-old man was admitted with jaundice. Mosapride was discontinued immediately, and methylprednisolone was administered for acute liver failure. The patient's data showed improvement, and he was discharged on Day 32. In both cases, mosapride gave a positive response to a drug-induced lymphocyte stimulation test (DLST), and the patient's score based on the criteria for DILI was "highly probable".

Syndrome of inappropriate antidiuretic hormone secretion in a case of olfactory neuroblastoma without anti-diuretic hormone immunoreactivity: A case report and review of the literature

Olfactory neuroblastoma (ONB) is a relatively rare nasal or paranasal malignant tumor. This tumor is rarely accompanied by paraneoplastic syndromes such as syndrome of inappropriate antidiuretic hormone secretion (SIADH). Here, we report a 31-year-old female with histologically confirmed ONB who had been diagnosed with SIADH three years prior. She was treated with surgery followed by concurrent chemoradiotherapy. SIADH resolved immediately after surgical tumor resection. Immunohistochemically, both biopsy and resected specimens from the nasal cavity had been negative for ADH. Although extremely rare, ONB may be associated with SIADH, and the possibility of this cancer should be taken into account during the follow-up of idiopathic SIADH.

Primary combined small cell carcinoma and squamous cell carcinoma of the oropharynx with special reference to EGFR status of small cell carcinoma component: Case report and review of the literature

Combined small cell carcinoma (SCC) and squamous cell carcinoma (SqCC) of the oropharynx is extremely rare and shows an aggressive clinical course. There are only 5 reported cases of combined SCC and SqCC in the English language literature. Here, we report a 59-year-old male presenting with a right tonsillar mass. The mass was biopsied, and the histological findings showed a proliferation of small-sized tumor cells with scant cytoplasm. Immunohistochemically, the tumor cells were positive for neuroendocrine markers (synaptophysin, chromogranin A, and CD56). Our first diagnosis was tonsillar small cell carcinoma. We treated the patient with concurrent chemoradiotherapy together with cisplatin followed by surgery. The resected tonsillar specimen showed a residual tumor composed of SCC and SqCC, and lymph nodes showed metastatic tumor cells of the SCC component. Immunohistochemically, the SCC component was positive for all neuroendocrine markers and p16; on the other hand, the SqCC component was positive for p40, p63, p16, and EGFR. Fluorescence in situ hybridization revealed that neither component showed any EGFR gene copy number gain. The patient was treated with adjuvant chemotherapy consisting of irinotecan and cisplatin. Liver and bone metastases developed, resulting in the death of the patient. We discuss the present case and review similar cases. Most cases of combined SCC and SqCC occur regardless of p16 status, and a therapeutic strategy has yet to be determined. Further examination of this kind of combined tumor is necessary.

Molecular Pathobiology of Gastric Cancer

Gastric carcinogenesis is a multistep process, during which numerous genetic and epigenetic alterations accumulate: there are abnormalities of growth factors/receptors, angiogenic factors, cell cycle regulators, DNA mismatch repair genes etc. These abnormalities define, at the same time, the biological character of the cancer cell and may thus serve as therapeutic targets. Genetic instability may cause accumulation of genetic abnormalities. The most important epigenetic alterations are DNA methylation, histone modification and chromatin remodeling. Some of these changes are common in gastric cancer, regardless of subtype, and some differ by histological type or (gastric or intestinal) mucin phenotype. Genetic polymorphism is a crucial endogenous cause and fundamental aspect of cancer risk. Importantly, genetic polymorphisms are also associated with the therapeutic efficacy and toxicity of anti-cancer drugs. Genomic science and technology such as Serial Analysis of Gene Expression (SAGE) allows the identification of novel genes and molecules specifically up-regulated or down-regulated in gastric cancer, e.g., RegIV and claudin-18 can be identified. Advances in our understanding of the genetic and molecular bases lead to improved diagnosis, personalised medicine and prevention of gastric cancer.

A case of primary biliary cirrhosis in a patient with rheumatoid arthritis

The true prevalence of PBC in RA is not well known. Herein, we report an unusual case of a patient with PBC and RA, and discuss the association between these two diseases. PBC should be ruled out in the differential diagnosis of patients with RA having abnormal liver function tests.

Prognostic significance of urine N1, N12-diacetylspermine in patients with non-small cell lung cancer

BACKGROUND

Recently N(1),N(12)-diacetylspermine, a diacetylated polyamine derivative, was recognized as a tumor marker in patients with several kinds of cancers. However, the significance of its levels in urine as a prognostic factor has not been elucidated. In the present study, we examined whether the urine N(1),N(12)-diacetylspermine levels can be used as a prognostic factor in patients with NSCLC.

PATIENTS AND METHODS

Urine samples from 251 patients with NSCLC were collected prior to surgery and the urinary N(1),N(12)-diacetylspermine concentration was measured. Thereafter, all 251 patients underwent curative surgery and the analysis of prognosis was performed for over 10 years. Out of the 251 patients, 91 had recurrent disease. The significance of the urinary N(1),N(12)-diacetylspermine level as a prognostic factor among all 251 patients and among the 91 patients with recurrence was evaluated.

RESULTS

Univariate analysis of all 251 patients showed that the level of urinary N(1),N(12)-diacetylspermine was a significant prognostic factor for disease-free survival and overall survival; however, multivariate analysis showed it had no significance. Conversely, the univariate and multivariate analyses of post-recurrent survival of the 91 patients with recurrence showed that urinary N(1),N(12)-diacetylspermine was an independent prognostic factor for post-recurrent survival.

CONCLUSION

Patients with recurrence with positive urinary N(1),N(12)-diacetylspermine should undergo more intensive care and determination of urinary N(1),N(12)-diacetylspermine may contribute to improvement of prognosis of NSCLC.

Preoperative chemoradiotherapy using cisplatin plus S-1 can induce downstaging in patients with locally advanced (stage III) non-small-cell lung cancer

BACKGROUND

About 30% of patients with non-small cell lung cancer (NSCLC) have locally advanced cancer (stage IIIA or IIIB) at the time of presentation. Many institutions have reported treatment with preoperative chemoradiotherapy (PCRT) followed by curative resection in patients with stage III NSCLC, but the optimal therapeutic protocol for this group has not been established.

PATIENTS AND METHODS

Nineteen patients with stage III NSCLC were treated with PCRT, followed by surgery at the Hamanomachi Hospital, Fukuoka, Japan from May 2000 to November 2011. We evaluated the effectiveness of PCRT for inducing downstaging using mainly three chemoradiotherapy regimens; cisplatin plus Tegafur-Gimeracil-Oteracil Potassium (S-1), cisplatin plus Tegafur-Uracil (UFT), or 1,1'cyclobutanedicarboxylate (Carboplatin, CBDCA) plus paclitaxel, with concurrent radiation therapy in 19 patients with stage III NSCLC.

RESULTS

The overall 5-year survival rate was 57.1%, which is higher than the average survival rate for patients with stage III NSCLC in Japan. Among the regimens used, only cisplatin plus S-1 with concurrent radiation therapy significantly induced downstaging. There was a significant difference in survival time between the downstaged and non-downstaged groups. However, there was no significant difference in survival time between the S-1 plus cisplatin group and the other groups combined, because of the short observation period for the S-1 plus cisplatin group.

CONCLUSION

PCRT using cisplatin plus S-1 with concurrent radiation therapy is useful for inducing downstaging in patients with locally advanced stage III NSCLC.

Serum olfactomedin 4 (GW112, hGC-1) in combination with Reg IV is a highly sensitive biomarker for gastric cancer patients

Gastric cancer (GC) is 1 of the most common human cancers. Early detection remains the most promising approach to improving long-term survival of patients with GC. We previously performed Serial Analysis of Gene Expression (SAGE) on 4 primary GCs and identified several GC-specific genes including Reg IV. Of these genes, olfactomedin 4 (OLFM4, also known as GW112 or hGC-1) is a candidate gene for cancer-specific expression. In this study, we examined the expression of olfactomedin 4 in human GC by immunohistochemistry. We also assessed serum olfactomedin 4 levels in GC patients by enzyme-linked immunosorbent assay. 94 (56%) of 167 GC cases were positive for olfactomedin 4 by immunostaining. Olfactomedin 4 staining was observed more frequently in stage I/II cases than in stage III/IV cases. The serum olfactomedin 4 concentration in presurgical GC patients (n = 123, mean +/- SE, 36.3 +/- 3.5 ng/mL) was significantly higher than that in healthy individuals (n = 76, 16.6 +/- 1.6 ng/mL). In patients with stage I GC, the sensitivity of serum olfactomedin 4 (25%) and Reg IV (35%) was superior to that of CA19-9 (5%) or CEA (3%). Furthermore, in patients with stage I GC, the combination of olfactomedin 4 and Reg IV elevated the diagnostic sensitivity to 52%. These results suggest that serum olfactomedin 4 is a useful marker for GC and its measurement alone or in combination with Reg IV has utility in the early detection of GC.

Transcriptome dissection of gastric cancer: identification of novel diagnostic and therapeutic targets from pathology specimens

Gastric cancer is the fourth most common malignancy in the world, and mortality due to gastric cancer is second only to that from lung cancer. 'Transcriptome dissection' is a detailed analysis of the entire expressed transcripts from a cancer, for the purpose of understanding the precise molecular mechanism of pathogenesis. Serial analysis of gene expression (SAGE) is a suitable technique for performing transcriptome dissection. Gastric cancers of different stages and histology were analyzed on SAGE, and one of the largest gastric cancer SAGE libraries in the world was created (GEO accession number GSE 545). Through SAGE, many candidate genes have been identified as potential diagnostic and therapeutic targets for the treatment of gastric cancer. Regenerating islet-derived family, member 4 (Reg IV) participated in 5-fluorouracil (5-FU) resistance and peritoneal metastasis, and its expression was associated with an intestinal phenotype of gastric cancer and with endocrine differentiation. GW112 expression correlated with advanced tumor stage. Measurement of Reg IV and GW112 levels in sera indicated a sensitivity of 57% for detection of cancer. SPC18 participated in tumor growth and invasion through transforming tumor growth factor-alpha upregulation. Palate, lung, and nasal epithelium carcinoma-associated protein (PLUNC) was a useful marker for gastric hepatoid adenocarcinoma. Expression of SOX9, HOXA10, CDH17, and loss of claudin-18 expression were associated with an intestinal phenotype of gastric cancer. Information obtained from transcriptome dissection greatly contributes to diagnosis and treatment of gastric cancer.

Transcriptome dissection of gastric cancer: identification of novel diagnostic and therapeutic targets from pathology specimens

Gastric cancer is the fourth most common malignancy in the world, and mortality due to gastric cancer is second only to that from lung cancer. 'Transcriptome dissection' is a detailed analysis of the entire expressed transcripts from a cancer, for the purpose of understanding the precise molecular mechanism of pathogenesis. Serial analysis of gene expression (SAGE) is a suitable technique for performing transcriptome dissection. Gastric cancers of different stages and histology were analyzed on SAGE, and one of the largest gastric cancer SAGE libraries in the world was created (GEO accession number GSE 545). Through SAGE, many candidate genes have been identified as potential diagnostic and therapeutic targets for the treatment of gastric cancer. Regenerating islet-derived family, member 4 (Reg IV) participated in 5-fluorouracil (5-FU) resistance and peritoneal metastasis, and its expression was associated with an intestinal phenotype of gastric cancer and with endocrine differentiation. GW112 expression correlated with advanced tumor stage. Measurement of Reg IV and GW112 levels in sera indicated a sensitivity of 57% for detection of cancer. SPC18 participated in tumor growth and invasion through transforming tumor growth factor-alpha upregulation. Palate, lung, and nasal epithelium carcinoma-associated protein (PLUNC) was a useful marker for gastric hepatoid adenocarcinoma. Expression of SOX9, HOXA10, CDH17, and loss of claudin-18 expression were associated with an intestinal phenotype of gastric cancer. Information obtained from transcriptome dissection greatly contributes to diagnosis and treatment of gastric cancer.

Characteristic gene expression in stromal cells of gastric cancers among atomic-bomb survivors

To elucidate the mechanism of radiation-induced cancers, molecular analysis of cancers in atomic-bomb survivors is important. In our study, we developed a custom oligonucleotide array of 208 genes. We analyzed gene expression profiles of gastric cancers (GCs) from atomic-bomb survivors and identified 9 genes with significantly lower expression in GCs from exposed patients than in GCs from nonexposed patients. Among these 9 genes, expression of versican and osteonectin was investigated in greater detail using immunohistochemistry in 116 GCs from 64 exposed and 52 nonexposed patients who developed GC after the bombing. In the Stage I/II GCs, the clinicopathologic, phenotypic and proliferative characteristics of GCs from exposed and nonexposed patients did not differ significantly; however, versican and osteonectin were expressed at much lower levels in the area of tumor-associated stroma of exposed patients than in nonexposed patients (p = 0.026 and p = 0.024, respectively). These results suggest that the characteristics of tumor-associated stromal cells differ between GCs from exposed and nonexposed patients.

Combination analysis of a whole lymph node by one-step nucleic acid amplification and histology for intraoperative detection of micrometastasis

OBJECTIVE

The aim was to develop a more efficient molecular detection system than histological examination (HE) for lymph node (LN) metastasis.

METHODS

Cytokeratin (CK) 19 mRNA copy numbers of 5 colon carcinoma cell lines (Lovo, DLD1, WiDr, Colo201 and Colo320) were calculated and compared by one-step nucleic acid amplification (OSNA) and conventional real-time reverse-transcription polymerase chain reaction (RT-PCR). Then, 91 LN submitted for HE from 6 patients with advanced colorectal adenocarcinoma and 64 LN submitted for frozen diagnosis from 47 patients with different malignancies were examined by OSNA and HE.

RESULTS

CK19 mRNA copy numbers of all but Colo320 cells detected by OSNA were within double of those detected by RT-PCR. The least cell count of Lovo cells detected at one reaction (2 microl) by OSNA was calculated as 0.8 cells. Carcinoma metastasis showing either HE+ or OSNA+ was detected in 7.9% of the LN from advanced colorectal adenocarcinomas and in 30.0% of the LN for frozen diagnosis from different malignancies; HE-/OSNA+ metastasis was detected in 4.8 and 4.0%, respectively. OSNA analysis of 1 LN could be completed within 40 min.

CONCLUSION

A combined analysis of LN by HE and OSNA could increase the sensitivity for detecting micrometastasis during surgery.

Molecular characteristics of differentiated-type gastric carcinoma with distinct mucin phenotype: LI-cadherin is associated with intestinal phenotype

Gastric carcinomas (GC) are classified into four phenotypes on the basis of the mucin expression profile: G type (gastric or foveolar phenotype), I type (intestinal phenotype), GI type (intestinal and gastric mixed phenotype) and N type (neither gastric nor intestinal phenotype). Immunohistochemistry was used to examine the expression of epidermal growth factor receptor (EGFR), E-cadherin, liver-intestine (LI)-cadherin, CD44v9 and p53 and correlation of these molecules with mucin phenotype and tumor stage was evaluated. Overexpression of EGFR and LI-cadherin, reduced expression of E-cadherin and abnormal expression of p53 were observed more frequently in advanced GC than in early GC. Among I-type GC, overexpression of EGFR and reduced expression of E-cadherin were observed more frequently in advanced tumors than in early tumors. Among G-type GC, reduced expression of E-cadherin was significantly associated with advanced tumors. With respect to the relationship between mucin phenotype and expression of cancer-related molecules, overexpression of LI-cadherin was observed more frequently in I-type (12/25, 48.0%) than in G-type (1/14, 7.1%) GC. I-type GC tended to express LI-cadherin more frequently than GI-type GC. These results provide insights into the molecular characteristics of the distinct mucin phenotype of differentiated-type GC and suggest that LI-cadherin may contribute to the biological behavior of I-type GC.

Accumulation of DNA methylation is associated with tumor stage in gastric cancer

BACKGROUND

The authors purpose in this study was to clarify the difference in terms of clinicopathologic features between gastric cancer (GC) with high numbers of DNA methylated genes and CpG island methylator phenotype (CIMP)-positive GC as originally defined.

METHODS

We analyzed DNA methylation of 12 tumor-related genes (hMLH1, MGMT, p16(INK4a), CDH1, RAR-beta, HLTF, RIZ1, TM, FLNc, LOX, HRASLS, HAND1) in 75 samples of GC from 75 patients, 25 samples of corresponding nonneoplastic mucosa from 25 patients, and 10 samples of normal gastric mucosa from 10 healthy young individuals by methylation-specific polymerase chain reaction (PCR) and bisulfite PCR. We also investigated CIMP status by examining the methylation of five MINT loci and p53 mutation status by PCR single-strand conformation polymorphism. We measured levels of expression of mRNAs for these 12 genes by quantitative reverse transcription PCR in 50 GC specimens.

RESULTS

The average number of methylated genes per tumor was 4.83. DNA methylation of each gene was correlated with low expression of the respective mRNA. High methylation (GC with 5 or more methylated genes) was detected in 39 (52.0%) of 75 GCs. Twenty-nine (37.8%) of 75 GCs were CIMP-positive. DNA methylation of each of the 12 genes was observed more frequently in the high-methylation group than in the low-methylation group. Methylation of 6 specific genes occurred more frequently in CIMP-positive GC than in CIMP-negative GC. Methylation of the remaining 6 genes was not correlated with CIMP-status. High methylation was found more frequently in Stage III/IV GC (26 of 40 cases, 65.0%) than in Stage I/II GC (13 of 35 cases, 37.1%, P = 0.029).CONCLUSIONS.These findings indicate that GCs with higher numbers of methylated genes have more distinct DNA methylation profiles than the originally defined CIMP-positive GCs. DNA methylation of tumor-related genes accumulates in conjunction with tumor progression.

DNA methylation profiles of differentiated-type gastric carcinomas with distinct mucin phenotypes

Gastric carcinomas (GC) are classified into four phenotypes according to mucin expression. Previous studies revealed the association of distinct genetic profiles in GC with mucin phenotypic expression; however, the roles of epigenetic changes, such as DNA methylation, are poorly understood. We examined whether the phenotypic expression of GC was associated with DNA methylation of hMLH1, MGMT, p16(INK4a), RAR-beta or CDH1. Expression of HGM, M-GGMC-1, MUC2, and CD10 was analyzed immunohistochemically in 33 advanced GC with differentiated histology. HGM was expressed in 14 (42.4%) cases, M-GGMC-1 in five (15.2%) cases, MUC2 in 15 (45.5%) cases and CD10 in 18 (54.5%) cases. DNA methylation was detected in five (15.2%) cases for hMLH1, 11 (33.3%) cases for MGMT, 13 (39.4%) cases for p16(INK4a), 17 (51.5%) cases for RAR-beta and 14 (42.4%) cases for CDH1 by bisulfite-polymerase chain reaction and methylation-specific polymerase chain reaction. DNA methylation of hMLH1 occurred more frequently in MUC2-negative GC than in MUC2-positive GC (P = 0.0488, Fisher's exact test). In contrast, MGMT was more frequently methylated in MUC2-positive GC than in MUC2-negative GC (P = 0.0078, Fisher's exact test). There was no correlation between gastric or intestinal-markers and methylation of the p16(INK4a), RAR-beta and CDH1 genes. These results indicate that DNA methylation of specific genes, such as hMLH1 and MGMT, may be involved partly in the distinct phenotypic expression of GC.

Expression of osteoprotegerin correlates with aggressiveness and poor prognosis of gastric carcinoma

Osteoprotegerin (OPG), identical with osteoclastogenesis inhibitory factor, is a member of a subgroup of the tumor necrosis factor (TNF)-receptor superfamily, which functions as a soluble decoy receptor. It has been reported that OPG expression is associated with bone metastasis of cancer of the breast and prostate. In the present study, we examined the expression of OPG in gastric carcinomas using immunohistochemistry and reverse-transcription polymerase chain reaction methods, and compared with clinicopathological parameters. The expression of OPG mRNA was confirmed in a gastric carcinoma cell line (MKN-7) and gastric carcinoma tissues. Immunohistochemically, strongly positive staining of OPG was found in 65% (67/103) of gastric carcinomas, whereas OPG protein was not detected in non-neoplastic mucosal epithelia. The expression of OPG protein in gastric carcinoma tissues correlates significantly with depth of tumor invasion, nodal metastases and advanced tumor stage. Furthermore, the prognosis of the cases with strong OPG expression was significantly worse than those with weak or no expression of OPG. These results suggest that OPG may participate in stomach carcinogenesis, invasion and metastasis, and may serve as a novel molecular marker for aggressive gastric cancer.

Increased expression but not genetic alteration of BRG1, a component of the SWI/SNF complex, is associated with the advanced stage of human gastric carcinomas

BRG1, a component of the SWI/SNF complex, regulates gene transcription through chromatin remodeling. Certain human cancer cell lines have been shown to contain homozygous deletions or mutations, half of which are concentrated in exons 4 and 10, resulting in aberrant BRG1 expression. We examined the expression of BRG1 in 38 gastric carcinomas and corresponding nonneoplastic mucosa by using the quantitative real-time RT-PCR method. Twenty-three carcinomas (61%) showed increased BRG1 expression in tumor tissue in comparison with that in nonneoplastic mucosa. The T/N ratio (the expression level of BRG1 mRNA in tumor tissues relative to those in corresponding nonneoplastic mucosa) in advanced cases of gastric carcinoma (stages III and IV) was significantly higher than that in cases of stage I and II carcinoma (p = 0.029). Furthermore, gastric carcinomas with lymph node metastasis showed a tendency to express BRG1 at a higher level than gastric carcinomas without metastasis (p = 0.097). We also searched for genetic alterations of the BRG1 gene in 8 gastric carcinoma cell lines and 33 primary gastric carcinomas by PCR-SSCP analysis. No SSCP variants in exons 4, 10 and 16 of the BRG1 gene were found in both gastric carcinoma cell lines and primary gastric carcinomas. These results suggest that, although genetic abnormality of BRG1 might be rare, an increased expression of BRG1 might be associated with the development and progression of gastric carcinoma.

Distinct promoter hypermethylation of p16INK4a, CDH1, and RAR-beta in intestinal, diffuse-adherent, and diffuse-scattered type gastric carcinomas

Hypermethylation of CpG islands in gene promoters is associated with silencing of various tumour suppressor genes. Recent studies of colorectal and gastric carcinomas have defined a CpG island methylator phenotype (CIMP), which involves the targeting of multiple genes by promoter hypermethylation. In this study, methylation-specific polymerase chain reaction (PCR) was performed to study methylation of CpG islands in the promoters of the p16(INK4a), cadherin 1 (CDH1), and retinoic acid receptor-beta (RAR-beta) genes in 45 gastric carcinomas and to investigate whether CDH1 and RAR-beta promoter hypermethylation is associated with CIMP-positive gastric carcinoma. CpG island hypermethylation of the p16(INK4a), CDH1, and RAR-beta promoters was detected in 12 (27%), 26 (58%), and 24 (53%) of the 45 gastric carcinomas, respectively. Hypermethylation of the p16(INK4a) promoter was more common in intestinal type than in diffuse type gastric carcinomas (p = 0.0023; Fisher's exact test) and was inversely associated with p53 mutations (p = 0.0225; Fisher's exact test). However, CDH1 and RAR-beta promoter hypermethylation was observed more frequently in diffuse-scattered type gastric carcinoma than in other types (intestinal and diffuse-adherent types) (p = 0.0175 and p = 0.0335, respectively; Fisher's exact test) and was not associated with p53 mutation status. Moreover, hypermethylation of the CDH1 and RAR-beta promoters occurred concordantly (p < 0.0001; Fisher's exact test). These results suggest that at least two types of promoter methylation status are involved in the development of the intestinal (p16(INK4a) promoter hypermethylation) and diffuse-scattered types (CDH1 and RAR-beta promoter hypermethylation) of gastric carcinoma.