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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.

The authors report a case of subacute sclerosing panencephalitis in a child who had measles during the neonatal period. At 3 years, 6 months of age, over a period of a few weeks, the patient lost the ability to sit unaided as a result of progressive truncal ataxia, without apparent cognitive changes, simulating acute cerebellar ataxia. His symptoms improved in 1 month, and he was able to walk again with support, but mental alteration and periodic mild head nodding on awakening followed. His illness was diagnosed as subacute sclerosing panencephalitis on the basis of the elevated titers of measles antibodies in the cerebrospinal fluid. Measles infection before 1 year of age is a risk factor of subacute sclerosing panencephalitis, but reports about patients with neonatal measles infection are rare. Immaturity of the brain at the time of measles infection may not only be a risk factor but may also influence the clinical course of the disease.

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.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.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.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.

Purpose: Ceramide generated from sphingomyelinase activation has been reported to play a role in cytokine-mediated events. Secretory sphingomyelinase (S-SMase), a product of the acid sphingomyelinase gene, has been found to be derived from many cell types and to exist in human serum. The purpose of the current study was to investigate the serum level of S-SMase. Patients and Methods: Three patients with hypercytokinemia caused by hemophagocytic lymphohistiocytosis (HLH) were studied. Serum samples were collected from the three patients with HLH, patients with a deficiency of acid sphingomyelinase, or type B Niemann-Pick disease, and normal controls. The S-SMase activities were determined using 14 C-sphingomyelin as a substrate. Results: The serum S-SMase activities were increased 10- to 20-fold in the sera from the three patients with HLH (P < 0.0001). The high S-SMase activity was decreased to the normal level along with the clinical improvement of HLH. Conclusions: Increased release of S-SMase from cells into the circulation is observed in patients with active HLH. The authors suggest that S-SMase is related to the pathophysiology of hypercytokinemia.

Enzyme activities of acid sphingomyelinase (ASM) were determined in various human cell-free body fluids, serum, cerebrospinal fluid, urine, salivary fluid, tear fluid, and synovial fluid, using assay buffers with or without Zn2+ -cation. Although ASM activity was not detected in the cerebrospinal fluid, the other fluids demonstrated significant enzyme activities of ASM. All ASMs detected in the fluids were stimulated by the addition of Zn2+ -cation, suggesting that those enzymes are secretory ASM derived from ASM gene. We suggest a possible enzymatic diagnosis of Niemann-Pick disease types A and B using those body fluids. Interestingly, salivary and tear fluids showed much higher activities of ASM than those of the other fluids. Because sphingolipids, especially sphingomyelin, are major constituents of a normal diet, especially, milk, eggs, and meat products, we suggest that ASM in the salivary gland may play an important role in the digestion of sphingomyelin in a normal diet.

A 56-year-old man experienced dyspnea since August 1995 and the chest X-ray film showed abnormal shadow. The diagnosis of bronchiolitis obliterans organizing pneumonia (BOOP) was established based on the histological findings of transbronchial lung biopsy. The patient was treated with prednisolone and symptoms improved. Myalgia and muscle weakness developed associated with relapse of BOOP after withdrawal of prednisolone. Patient was admitted to our department on December 1995 for further examination. An increased level of serum CPK, histological findings of muscle biopsy consistent with myositis, and positive anti-Jo-1 antibody were identified. Those findings supported a diagnosis of polymyositis (PM), and BOOP was considered as a pulmonary complication of PM. Myositis and pulmonary lesion improved after second course of steroid therapy and patient was discharged on May 1996. Both chronic pulmonary fibrosis and acute progressive interstital pneumonia are well known as pulmonary lesion associated with PM. The former is frequently recognized in cases of PM with anti-Jo-1 antibody and the latter is often observed in cases without autoantibodies. The association of PM and BOOP, however, has rarely been reported. The findings that BOOP frequently preceded PM and anti-Jo-1 antibody was positive in half of the cases were observed in the literature.

Choriocarcinoma occurring in a placenta and metastasizing to the fetus is quite rare. We describe here a case of such infantile choriocarcinoma, initially appeared as refractory anemia and rapidly metastasized to the liver, lungs, and brain. The placenta looked normal and was not submitted to histological examinations. Neither noninvasive nor invasive diagnostic methods (ultrasonography, computed tomography, magnetic resonance image, scintigraphy, and hepatic arteriography) gave any diagnostic information on the tumor. Liver biopsy was considered too risky due to a possible bleeding. Correct diagnosis was established only after the postmortem examination. Two months after the infant's death, we were informed that the mother was found having hepatic and pulmonary tumors. The importance of the maternal history and measurement of urinary human chorionic gonadotropin is emphasized for a rapid and correct diagnosis of infantile choriocarcinoma.

Objectives: Biologic and clinical characteristics of intraductal papillary-mucinous tumors of the pancreas (IPMTs) were studied in reference to immunohistochemical mucin (MUC1, MUC2, and MUC5AC) expression. Methods: Histologic grade, immunohistochemical ki-67 and p53 expression, and findings in imaging tests of 21 IPMTs (9 carcinomas, 6 borderline tumors, and 6 adenomas) were examined according to the mucin expression profile. Results: IPMTs were divided into groups: M1 group (MUC1+, n = 4), M2 group (MUC2 + MUC1−, n = 12), and M5 group (MUC5AC + MUC1−MUC2−, n = 5). The M2 group was subdivided into M2s (strongly positive) and M2w (weakly positive) groups. The rates of carcinoma in the M1, M2s, M2w, and M5 groups were 100%, 40%, 0%, and 0%, respectively. The Ki-67 labeling indexes were significantly higher in the M1 and M2s groups. p53 staining was positive in 50% and 40% of the IPMTs in the M1 and M2s groups, respectively, but in none of the IPMT in the M2w and M5 groups. Morphologic changes in imaging tests during the observation periods were most remarkable in the M1 group. Conclusions: Our results suggest that MUC1 is related to malignant character but MUC5AC alone is related to benign character in IPMTs and that malignant potential of IPMTs expressing MUC2 depends on the degree of MUC2 expression.