Kyosuke Ohta

Expression of HNF-1α and HNF-1β in various histological differentiations of hepatocellular carcinoma

Hepatic nuclear factor 1 (HNF‐1) regulates genes in a hepatocyte‐specific manner. It has been previously reported that the ratio of HNF‐1α and HNF‐1β mRNA is related to histological differentiation hepatocellular carcinoma (HCC). In this study, the expression levels of the HNF‐1α and HNF‐1β proteins were analysed relatively and quantitatively in various histologically differentiated HCC and surrounding non‐cancerous tissues, and HNF‐1α binding activity for the AT element of the B domain of the human α‐fetoprotein enhancer was examined. Western blot analysis demonstrated that HNF‐1α protein was expressed at a higher level in well‐differentiated HCC tissues than in the surrounding non‐HCC tissues; on the other hand, the HNF‐1α protein was expressed at lower levels in moderately and poorly differentiated HCCs than in the surrounding non‐HCC tissues. The levels of HNF‐1β expression in well‐differentiated and poorly differentiated HCCs were similar to and higher than those found in the respective surrounding non‐cancerous portions. In binding assays, HNF‐1 binding activity was high in well‐differentiated HCC and lower in moderately and poorly differentiated HCCs. Most well‐differentiated HCC cases showed immunohistochemical expression of HNF‐1α. These findings show that poor histological differentiation of HCC correlates with decreases in the level and activity of HNF‐1α proteins.

Telomerase activity in hepatocellular carcinoma as a predictor of postoperative recurrence

Telomerase is a ribonucleoprotein that stabilizes telomeres and allows unlimited cell division. It has been reported that most cancer cells evince reactivated telomerase. We examined telomerase activity in 29 patients with hepatocellular carcinoma (HCC) by a polymerase chain reaction-based semiquantitative assay. Of 24 HCCs, telomerase activity was positive in 23 (95,8%), of which 16 showed strong activity. In 11 well differentiated HCCs, telomerase activity was strong in 5, weak in 5, and undetected in 1 and in 13 moderately differentiated HCCs, it was strong in 11 and weak in 2. Five of 6 HCCs less than 2 cm in diameter expressed strong telomerase activity, while weak telomerase activity was detected in 7 of 19 (36.8%) resected noncancerous liver tissues from the HCC patients. Five of these 7 patients (71%) manifested recurrence within 6 months after surgery. The recurrence rate in these patients whose noncancerous liver tissue was positive for telomerase activity was significantly higher than that in patients in whom it was negative (P=0.017). These results suggest that the presence of telomerase activity may be a useful diagnostic marker of HCC, regardless of tumor size, and that its detection in resected noncancerous liver tissues may serve as a useful predictor of postoperative recurrence.

Expression of EGF, EGF-receptor, p53, v-erb B and ras p21 in colorectal neoplasms by immunostaining paraffin-embedded tissues.

Immunohistochemical studies were performed to clarify the significance of the expression or overexpression of epidermal growth factor (EGF), EGF‐receptor (EGFR), p53, v‐erb B, ras p21 in 23 cases each of tubular adenoma and adenocarcinoma. The expression of EGF, EGFR, p53, v‐erb B, and ras p21 in paraffin‐embedded tissues, from 46 patients with colorectal tumors (adenoma: 23 cases; 14 mild dysplasia, six moderate dysplasia, three severe dysplasia, adenocarcinoma: 23 cases; 17 well differentiated, two moderately differentiated, three poorly differentiated, one mucinous carcinoma was analyzed immunohistochemically using anti‐EGF, EGFR, p53, v‐erb B and ras p21 antibodies. The EGF and ras p21 tended to express more strongly in carcinoma cases than in the adenoma cases, and in severe and moderate dysplasia than in mild dysplasia (EGF: stained positive in five adenomas [21.74%] and 17 adenocarcinomas [73.91%]; ras p21: stained positive in six adenomas [26.09%] and 14 adenocarcinomas [60.87%]. The EGFR stained positive in two adenomas (8.70%) and two adenocarcinomas (8.70%). The p53 and v‐erb B showed positive staining only in the carcinoma cases (p53: stained positive in four cases [17.39%]; v‐erb B: stained positive in eight cases [34.78%]). This study suggests that these factors seem to have some role in the progression of colon neoplasms. It suggests that genetic alteration is not always equal to the overexpression of protein products, but that it reflects them well, and that the staining makes some contribution to differential diagnosis in colorectal neoplasms.

Postmortem autolysis in the pancreas: multivariate statistical study. The influence of clinicopathological conditions.

The pancreases of 92 autopsied patients were evaluated to determine the influence of clinicopathological conditions upon the extent of postmortem autolysis. The postmortem interval was the most important factor influencing postmortem autolysis. In order to more precisely evaluate the influence of associated factors upon the extent of postmortem autolysis in the pancreas, quantification I of multivariate statistical analysis was used. Twelve factors such as postmortem interval, mode of death, malignant neoplasia as an underlying cause of death, and history of abdominal surgery were chosen for analysis. The multiple correlation coefficient (R2) was 0.71. In the case of unexpectedly severe or unexpectedly mild postmortem autolysis, we suggest that these 12 factors should be taken into close consideration whether or not the postmortem interval is long or short.

The Effect of Dietary Nucleic Acid Deficiency and the Administration of a Nucleotide and Nucleosides Mixture Solution on Endotoxin Shock in Rats

The importance of dietary nucleic acid in modulation of immune function without disease has been reported in nutritional disorder except under surgical stress. Dietary nucleic acid deficiency decreases T lymphocytes function1 and dietary ribonucleic acid (RNA) enhances immune response2. However, it is not known whether dietary nucleic acid influences on macrophage function. Recently, monocytes/macrophages are considered as key factors in the pathogenesis of systemic inflammatory response leading to septic shock by producing humoral mediators under endotoxin stimulation3, 4. Therefore, the aim of this study is to evaluate the influence of dietary nucleic acid deficiency on endotoxin shock and macrophage functions stimulated with lipopolysaccharide (LPS), which is the major component of endotoxin. Then, the effect of intraperitoneal administration of a nucleotide and nucleosides mixture solution (OG-VI)5 was evaluated.

Utilization of purine and pyrimidine in human gastric cancer cells (KATO III): effect of a nucleotide and nucleosides mixture (OG-VI) solution on proliferation with coadministration of 5-fluorouracil.

Purine and pyrimidine are essential for cellular proliferation1, 2, 3. But, purine and pyrimidine are synthesized from glutamine in de novo synthesis pathway and cultured cancer cells do not require them in the medium. This is the reason that utilization of nucleosides by human cancer cells and their changes with 5 fluorouracil (5FU), the fluorinated analogue of uracil which is used in chemotherapy for various tumors2, 3, has not been reported. In this study, as a source of purine and pyrimidine, a solution containing a mixture of nucleosides and a nucleotide (OG-VI), developed recently as a nutritional supplement4, was used in the medium. It consists of purines, guanosine 5’-mono-phosphate (5’-GMP) and inosine, and pyrimidines, cytidine, uridine, and thymidine (TdR). It is known to increases hepatic regeneration and improve protein metabolism after partial hepatectomy in rats5, 6, and increase DNA synthesis in primary cultured hepatocytes7.