Manabu Nakashima

Nutritional investigation of non-obese patients with non-alcoholic fatty liver disease: the significance of dietary cholesterol.

Objective. The onset and progression of non-alcoholic fatty liver disease (NAFLD) seem to be affected by nutritive intake; however, detailed examinations have not been performed in non-obese NAFLD patients. The purpose of this study was to identify potential nutritive factors that affect NAFLD and its related nutritional problems. Material and methods. We investigated the distribution of abdominal fat, dietary intake, and biochemical data in patients with NAFLD and compared non-obese with obese patients. Results. There was no significant difference in the percentage of patients with diabetes or dyslipidemia between the obese and non-obese groups. Waist circumference, total abdominal fat levels, and subcutaneous fat levels were significantly higher in the obese group, while visceral fat levels were not significantly different between the two groups. Immunoreactive insulin (IRI) and homeostasis model assessment-insulin resistance (HOMA-IR) were significantly lower in the non-obese group, suggesting that the non-obese patients were not overtly insulin resistant. Although serum adiponectin and TNF-α levels were similar in both groups, leptin levels were significantly higher in the obese group. Total energy and carbohydrate intake tended to be higher in the obese group. A characteristic feature was that dietary cholesterol intake was significantly higher, while the intake of polyunsaturated fatty acids (PUFAs) was significantly lower in the non-obese group. Conclusions. In non-obese NAFLD patients: 1) although visceral fat was increased, insulin resistance and/or dysregulated secretion of adipocytokines was not necessarily shown; 2) intakes of total energy and carbohydrates were not excessive, although dietary cholesterol was superabundant and dietary PUFAs were significantly lower compared with those in obese patients; and 3) characteristic fat intake may be associated with the formation of NAFLD.

A Novel Tumor-Associated Antigen Expressed in Human Uterine and Ovarian Carcinomas

A large number of monoclonal antibodies (MoAbs) against human tumor cells have been generated and it has been shown that these MoAbs are useful tools in the diagnosis and treatment of cancer patients, as well as in the basic investigation of the oncogenesis and characterization of cancer cells.

A newly identified MAGE‐3‐derived epitope recognized by HLA‐A24‐restricted cytotoxic T lymphocytes

Five MAGE‐3‐derived peptides carrying an HLA‐A24‐binding motif were synthesized. Binding capacity of these peptides was analyzed by an HLA‐class‐I stabilization assay. Two of the 5 peptides bound to HLA‐A*2402 molecule with high affinity, and 3 peptides with low affinity. Peripheral‐blood mononuclear cells (PBMC) depleted of CD4+T cells were stimulated with the peptides to determine whether these peptides would induce cytotoxic T lymphocytes (CTL) from PBMCs obtained from 7 healthy HLA‐A*2402+ donors. Peptide M3‐p97 (TFPDLESEF; corresponding to amino‐acid residues 97–105 of MAGE‐3), with high binding capacity to the HLA‐A*2402 molecule, elicited the peptide‐specific and HLA‐A24‐restricted CD8+CTL lines in 2 of the 7 donors, while none of the 4 other peptides induced CTL specific for the corresponding peptide in any of the donors. CTL lines induced by stimulation with peptide M3‐p97 exhibited cytolytic activities against HLA‐A*2402 transfectant cell lines (C1R‐A*2402) in the presence of peptide M3‐p97, but not in unloaded or irrelevant peptide‐pulsed C1R‐A*2402 cells. The CTL lines and a cloned CD8+CTL isolated from one of the bulk populations by limiting dilution could lyse MAGE‐3+/HLA‐A*2402+ squamous‐cell‐carcinoma(SCC) lines but neither MAGE‐3−/HLA‐A*2402+ nor MAGE‐3+/HLA‐A*2402− SCC lines, indicating that M3‐p97 can be naturally processed and presented on the tumor‐cell surface in association with HLA‐A*2402 molecules. Combined with the 4 currently reported CTL epitopes derived from MAGE‐3 and presented by HLA‐A1, HLA‐A2, HLA‐A24 or HLA‐B44, identification of this CTL epitope presented by the HLA‐A*2402 molecule will extend the application of MAGE‐3‐derived peptides for immunotherapy for cancer patients. Int. J. Cancer 81:387–394, 1999.

Expression and prognostic significance in lung cancer of human tumor‐associated antigen RCAS1

A new monoclonal antibody (MAb), 22‐1‐1, acts against a novel tumor‐associated antigen (Ag) strongly expressed in human uterine cervical adenocarcinomas. A cDNA encoding the Ag recognized by the 22‐1‐1 MAb has been isolated and called RCAS1 (receptor‐binding cancer antigen expressed on SiSo cells). RCAS1 can induce growth arrest and apoptosis in RCAS1 receptor‐positive cells including T cells and natural killer cells in vitro. These results suggest that RCAS1 is involved in tumor escape from the immune system. Immunohistochemical analysis revealed the relationship between RCAS1 expression and clinicopathological variables (age, sex, smoking, histology, differentiation grade, pathological T factor, N factor and stage) and the prognostic significance of RCAS1 in 66 lung‐cancer patients who underwent curative operations: 33 adenocarcinomas, 24 squamous‐cell carcinomas, 3 large‐cell carcinomas, 4 adenosquamous carcinomas and 2 small‐cell carcinomas. Median follow‐up period of 64 non‐small‐cell carcinomas (NSCLCs) was 67.4 months. RCAS1 was expressed in 74.2% of lung cancers. RCAS1 in NSCLC cases with advanced T factor or pathological stage or in poorly differentiated adenocarcinomas was highly expressed. Furthermore, RCAS1 expression inducing apoptosis of tumor‐infiltrating lymphocytes was a significant prognostic factor in NSCLC (p < 0.03). Int. J. Cancer 89:488–493, 2000.

NPC1L1 inhibitor ezetimibe is a reliable therapeutic agent for non-obese patients with nonalcoholic fatty liver disease

BackgroundWe recently examined the distribution of abdominal fat, dietary intake and biochemical data in patients with nonalcoholic fatty liver disease (NAFLD) and found that non-obese NAFLD patients did not necessarily exhibit insulin resistance and/or dysregulated secretion of adipocytokines. However, dietary cholesterol intake was superabundant in non-obese patients compared with obese patients, although total energy and carbohydrate intake was not excessive. Therefore, excess cholesterol intake appears to be one of the main factors associated with NAFLD development and liver injury.MethodsWe reviewed a year of follow-up data of non-obese NAFLD patients treated with Niemann-Pick C1 like 1 inhibitor ezetimibe to evaluate its therapeutic effect on clinical parameters related to NAFLD. Without any dietary or exercise modification, 10 mg/day of ezetimibe was given to 8 patients. In 4 of 8 patients, ezetimibe was administered initially. In the remaining 4 patients, medication was switched from ursodeoxycholic acid to ezetimibe.ResultsIn each patient, body mass index was maintained under 25 kg/m2 during the observation period. Serum ALT levels significantly decreased within 6 months and in 4 patients levels reached the normal range (<30 U/L), which was accompanied with at least a 10% decrease in serum total cholesterol and LDL-cholesterol. However, ultrasonographic findings of fatty liver did not show obvious improvement for a year.ConclusionWe conclude that the cholesterol absorption inhibitor ezetimibe can suppress hepatic injury in non-obese patients with NAFLD and that ezetimibe may offer a novel treatment for NAFLD.

Expression of tumor-associated antigen RCAS1 correlates significantly with poor prognosis in nonsmall cell lung carcinoma

RCAS1 is a recently discovered antigen molecule expressed on the membrane of cancer cells, and it acts as a ligand for a putative receptor present on immune cells such as T, B and NK cells. It has been suggested that RCAS1 expression is related to the escape of tumors from immune surveillance. In this study, the relation between RCAS1 expression and various clinicopathologic variables, including patient prognosis, was investigated in lung carcinoma through immunohistochemical analysis.

A chemical chaperone, sodium 4-phenylbutyric acid, attenuates the pathogenic potency in human α-synuclein A30P + A53T transgenic mice

Aggregation and cytotoxicity of misfolded alpha-synuclein are postulated to be crucial in the disease processes of Parkinsons disease (PD) and other synucleinopathies. Mutations in the alpha-synuclein gene in some pedigrees of familial PD have been reported. The mutant alpha-synuclein has been reported to form fibrillar aggregates resulting in biochemical abnormalities that are responsible for the onset of familial PD. Thus, any agent that effectively prevents the development of misfolded and aggregated alpha-synuclein would be a disease modifying therapeutic candidate. We examined the efficacy of sodium 4-phenylbutyric acid (PBA), one of the chemical chaperons, in transgenic (Tg) mice overexpressing human alpha-synuclein containing a double mutation (A30P + A53T). To evaluate the therapeutic efficacy, bradykinesia and motor coordination were assessed using a pole test and a rotarod treadmill task, respectively. After PBA treatment, these motor deteriorations gradually improved. In immunohistochemical examinations, both a loss of tyrosine hydroxylase-positive neurons and an increase of phosphorylated alpha-synuclein in the substantia nigra were inhibited, resulting in no depletion of the striatal dopamine content. These data suggest that PBA might be one of the therapeutic reagents for neurodegenerative disorders.

Expression of RCAS1 and FasL in human trophoblasts and uterine glands during pregnancy: the possible role in immune privilege

Pregnancy is an immunological balancing act. Trophoblasts do not express MHC class I or II, except HLA‐C and G, but express Fas ligand (FasL), which confers immune privilege. RCAS1 (receptor‐binding cancer antigen expressed on SiSo cells) has recently been recognized to play a role in immune evasion of the tumour cells. We therefore studied the involvement of RCAS1 and FasL in the infiltration of NK cells by examining the curettaged uterine contents of 20 cases of early stage of pregnancy. The cases were clinically divided into two groups; curettage was performed (A) due to the absence of foetal heart beats, and (B) due to spontaneous uterine bleeding and abortion. In group A, RCAS1 was expressed in the uterine glands and extravillous cytotrophoblasts, as was FasL. Infiltration of NK cells around the uterine glands was scarcely detected. In contrast, in group B, expression of both RCAS1 and FasL was strikingly decreased in both the level of expression and the numbers of RCAS1/FasL‐positive cells and massive infiltration of NK cells was frequently detected around the uterine glands. These findings suggest that a reduction in RCAS1 and FasL expression seems to be closely associated with activation and infiltration of maternal NK cells and destruction of uterine glands, resulting in rejection of the foetus. Thus, expression of RCAS1 and FasL in the uterine glands and cytotrophoblasts may play a role in the downregulation of the maternal immune response, thereby maintaining pregnancy at early stage.

Expression of a tumor-associated antigen RCAS1 in hepatocellular carcinoma.

RCAS1 has been reported as a tumor-associated antigen in uterine and ovarian carcinomas. In vitro studies on RCAS1 indicated that it might function as an apoptosis-inducing factor since binding between RCAS1 and its receptor induced apoptosis in receptor-expressing cells. In this study, 68 surgically resected samples of hepatocellular carcinoma (HCC) were prepared and RCAS1 expression was examined immunohistochemically, because RCAS1 was also positive in all HCC cell lines tested. Clinical and pathological parameters were then compared between RCAS1-positive and -negative HCC cases. As a result, RCAS1 is expressed in 26.5% of HCC cases and vascular invasion is observed at a much higher rate in the RCAS1-positive cases (72.2%) than in RCAS1-negative cases (24.0%). RCAS1 is not an antigen specific for gynecological cancers. In HCC cases, the RCAS1-positive percentage is not high, however, RCAS1-positive HCCs exhibited a trend towards invasive character.

Expression and diagnostic evaluation of the human tumor-associated antigen RCAS1 in pancreatic cancer

Introduction Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is one of the membrane molecules expressed on human cancer cells and is presumed to play a protective role for tumor cells against immune surveillance by inhibition of clonal expansion and induction of cell death in immunocytes. Aims To address whether RCAS1 is expressed in pancreatic cancer and whether serologic diagnostic evaluation is useful compared with that of carbohydrate antigen 19–9 (CA19–9) and soluble Fas ligand. Methodology Immunohistochemical expression of RCAS1 was examined by staining with a 22–1-1 monoclonal antibody, and serum RCAS1 concentrations were determined by an enzyme-linked immunosorbent assay in 20 cases of ductal adenocarcinoma of the pancreas and other pancreatic diseases. Results Immunohistochemically, RCAS1 detection occurred in 100% (20/20) of ductal adenocarcinoma of the pancreas cases, 100% (6/6) of intraductal papillary–mucinous adenoma of the pancreas cases, and 40% (2/5) of chronic pancreatitis cases. RCAS1 was found in the cytoplasm of cancer cells and ductal cells. Serum RCAS1 concentrations in patients with ductal adenocarcinoma of the pancreas were significantly higher than those in patients with chronic pancreatitis (p < 0.0001), acute pancreatitis (p < 0.005), and autoimmune pancreatitis (p < 0.001). RCAS1 concentrations in patients with intraductal papillary–mucinous adenoma of the pancreas were also significantly higher than those in patients with chronic pancreatitis (p < 0.05) and autoimmune pancreatitis (p < 0.05). Positive serum RCAS1 samples (concentration, ≥10 U/mL) were found most often in cases of pancreatic neoplasm (80% [16/20], ductal adenocarcinoma of the pancreas; and 60% [3/5], intraductal papillary–mucinous adenoma of the pancreas). By contrast, in cases of pancreatic inflammatory diseases, raised concentrations occurred in 9.4% (3/32) of chronic pancreatitis cases, none (0/6) of acute pancreatitis cases, and none (0/8) of autoimmune pancreatitis cases. The sensitivity of CA19–9 for ductal adenocarcinoma of the pancreas was 75% and the specificity was 73.1% compared with chronic pancreatitis. On the other hand, the sensitivity of RCAS1 for ductal adenocarcinoma of the pancreas was 80% and the specificity was 96.2% compared with chronic pancreatitis. The specificity of RCAS1 for chronic pancreatitis was higher than that of CA19–9. Serum soluble Fas ligand concentrations were not considerably different among these patients. Conclusions RCAS1 was highly expressed in ductal adenocarcinoma of the pancreas, and serum RCAS1 concentrations in patients with ductal adenocarcinoma of the pancreas were significantly higher than those in patients with other inflammatory pancreatic diseases. Our results indicate that serum RCAS1 concentrations could be a new marker in screening procedures for pancreatic cancer.