PubMed Health⌕ Search

Biomedical subjects

H Kuniyasu

Publications and source records attributed to H Kuniyasu.

At least 19 recordsLinked to original sources
PubMed2006

Determinants for prediction of malignant potential by metalloproteinase:E-cadherin ratio in prostate core needle biopsy.

According to a good correlation between in situ hybridization-based metalloproteinase-2/9:E-cadherin ratio (MER) and the pathological stage of prostate cancer, we set the cutoff line of MER at 6.0 (MER>6) to distinguish between organ-confined (pT2) and advanced diseases (pT3a-b/N1). In this study, we looked at the factors affecting MER and leading to a misprediction of the pathological stage. We examined MER in 39 paired specimens of prostate core needle biopsy and prostatectomy from the same patient and compared these MERs. In 34 (87%) of 39 cases, the MER of biopsy was correlated with the final pathological stage (pT2 vs. pT3a-b/N1). MER ranges in pT3a-b/N1 cancer were significantly wider than those in pT2 cancer (p < 0.01). The number of MER>6 fields in Gleason score 8-9 cancer was larger than that in Gleason score 7 cancer (p < 0.0001). In 5 cases where there was a failure to distinguish pT2 from pT3a-b/N1, the misdiagnosis was significantly associated with a small number of biopsies (4 or 6 specimens; p = 0.0469), a small amount of tumor tissue in biopsy specimens (less than 5 mm; p = 0.0492), and a wide MER range (more than 5.0; high intratumoral heterogeneity; p = 0.0202). Considering these factors increases the usefulness of preoperative prediction of the final pathological stage by MER in prostate cancer.

Biomarkers, Tumor↗
PubMed2005

Interleukin-15 and transforming growth factor alpha are associated with depletion of tumor-associated macrophages in colon cancer.

We examined the effects of IL-15 and TGF-alpha on the inhibition of macrophage infiltration into colon cancer tissue, and secretion of amphoterin from colon cancer cells. Production of IL-15 and/or TGF-alpha was associated with depletion of tumor-associated macrophages (TAMs) in both Dukes' B and C tumors (P = 0.0324 and 0.0051, respectively). Production of IL-15 and/or TGF-alpha was also associated with amphoterin mRNA expression in colon cancer tissues with TAM depletion in both Dukes' B and C tumors (P = 0.0167 and P = 0.0062, respectively). WiDr human colon cancer cells treated with IL-15 and/or TGF-alpha induced reduction of nucleus-localized amphoterin and an increase in cytosolic and membranous amphoterin. Moreover, IL-15 and/or TGF-alpha treatment increased amphoterin secretion by WiDr cells. Most notably, IL-15 and TGF-alpha treatment induced the increase of cytosol/membrane localization and secretion of amphoterin and the most pronounced effect among the treatments carried out. These results suggested that IL-15/TGF-alpha promotes depletion of TAMs and secretion of amphoterin in colon cancer.

Antigens, CD↗
PubMed2005

High concentration of deoxycholic acid abrogates in vitro transformation of IEC6 intestinal cells by azoxymethane.

In this study, we designed an in vitro azoxymethane (AOM)-induced carcinogenesis model and analyzed the effect of deoxycholic acid (DCA) on growth, apoptosis, genotoxicity, and transformation of IEC6 intestinal cells. CYP2E1 production was confirmed in IEC6 cells. The growth of IEC6 cells was enhanced by DCA (100 microg/ml). However, IEC6 cells treated with DCA (200 microg/ml) were inhibited and disappeared at 48 hrs after treatment. Apoptotic cells increased 11.2 times by treatment with DCA (200 microg/ml) as compared to cells with no treatment. DNA injury detected by comet assay was found in cells treated with AOM, but not in cells treated with DCA (100 microg/ml) and AOM. The number of colony formation in soft agar increased by AOM treatment. However, the number of foci treated with DCA (100 microg/ml) plus AOM was 69% that of cells treated with AOM alone. Two out of the 6 mice subcutaneously injected with AOM-treated IEC6 cells showed tumorigenesis, whereas IEC6 cells treated with DCA (100 microg/ml) plus AOM or DCA (100 microg/ml) alone did not form any tumor. Reduced protein expression of MLH1, Bcl-2 was detected in IEC6 cells treated with DCA (100 microg/ml). Production of Bax, pJNK, TGF-beta, TGFBRI, TGFBRII, and beta-catenin were higher in IEC6 cells treated with DCA (100 microg/ml) than that in cells with no treatment. These results suggest that high-dose DCA induced apoptosis and inhibited AOM-induced in vitro transformation of IEC6 cells.

Animals↗
PubMed2004

Suppressive effects of a selective cyclooxygenase-2 inhibitor, etodolac, on 4-nitroquinoline 1-oxide-induced rat tongue carcinogenesis.

The present study was conducted to examine effects of a clinically available selective cyclooxygenase (COX)-2 inhibitor, etodolac, on the development of rat tongue squamous cell carcinomas (SCCs) induced by 4-nitroquinoline 1-oxide (4-NQO), and on the immunohistochemically demonstrable expression of COX-2. Fischer 344 rats, 6 weeks old at the commencement, were administered 4-NQO at the doses of 20-30 ppm in their drinking water for 12 weeks. Then, etodolac was supplemented into the diet at doses of 150 and 300ppm for 16 weeks. Rats were sacrificed at 28 weeks and tongue lesions were histologically examined. The incidence and the multiplicity of SCCs induced by 4-NQO were dose-dependently reduced by etodolac, with significance at the highest dose of 300 ppm. Etodolac did not significantly affect the immunohistochemical expression of COX-2 in the lesions which did develop. These results indicate that etodolac can inhibit the development of rat tongue SCCs, probably by inhibiting COX-2 activity rather than its expression. Thus, etodolac may be a promising candidate chemopreventive agent for individuals at high risk of oral cancer.

4-Nitroquinoline-1-oxide↗
PubMed2004

Repression of MLH1 and MGMT genes in colon mucosa adjacent to implanted cancer in athymic mouse.

Hyperplastic mucosa adjacent to colon cancer, being a reactive change, accelerates cancer progression and its metastasis through expression of angiogenic factors. We investigated promoter methylation in hyperplastic mucosa adjacent to orthotopic KM12SM colon cancer in mice. In the hyperplastic mucosa adjacent to KM12SM tumors in the cecum of athymic mice, reductions in the levels of the mutL homologue 1 (MLH1) and O6-methylguanine-DNA methyltransferase (MGMT) proteins were detected by immunohistochemistry and immunoblotting. To examine the effects of growth factors and cytokines on promoter methylation and repressed expression of the MLH1 and MGMT genes, a rat intestinal epithelial cell line, IEC6, was treated with epidermal growth factor (EGF) and interleukin (IL)-15 for 35 days. Protein levels of MLH1 and MGMT were reduced in EGF- and IL-15-treated IEC6 cells. A methylation-sensitive restriction enzyme assay revealed that CpG methylation was present in the promoter regions of the MLH1 and MGMT genes in DNAs extracted from hyperplastic mucosa adjacent to KM12SM tumors. These findings suggest that promoter CpG methylation affects expression of MLH1 MGMT genes in hyperplastic mucosa adjacent to colon cancer.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Acetylated histone H4 is reduced in human gastric adenomas and carcinomas.

Acetylation of core histones is closely linked to transcriptional activation of various genes. The acetylation levels of nucleosomal histones can be modified through a balance of histone acetyltransferases and deacetylases. To elucidate the role of histone acetylation in human gastric carcinogenesis, we studied the status of histone H4 acetylation in gastric carcinoma tissues and corresponding non-neoplastic mucosa. The status of histone acetylation was assessed by examining the expression of acetylated histone H4 through Western blotting and immunohistochemistry using an anti-acetylated histone H4 antibody. The levels of acetylated histone H4 expression were obviously reduced in 72% (13/18) of gastric carcinomas in comparison with non-neoplastic mucosa by Western blotting. In immunohistochemistry, acetylated histone H4 was clearly detected in the nuclei of both non-neoplastic epithelial and stromal cells, whereas the levels of acetylated histone H4 were heterogeneous or reduced in 66% (38/57) of gastric carcinomas and 46% (6/13) of gastric adenomas. Reduced expression of acetylated histone H4 was also observed in some areas of intestinal metaplasia adjacent to carcinomas. Reduction in the expression of acetylated histone H4 was significantly correlated with advanced stage, depth of tumor invasion and lymph node metastasis. These results suggest that low levels of histone acetylation may be closely associated with the development and progression of gastric carcinomas, possibly through alteration of gene expression.

Acetylation↗
PubMed2001

Interferon-alpha prevents selection of doxorubicin-resistant undifferentiated-androgen-insensitive metastatic human prostate cancer cells.

BACKGROUND: We determined whether treatment of metastatic prostate cancer cells with doxorubicin (DOX) and interferon-alpha (IFN-alpha) prevented the emergence of highly undifferentiated tumor cells. METHODS: The state of cell differentiation was determined by analysis of prostate-specific antigen (PSA), E-cadherin, keratin, and vimentin. RESULTS: Human prostate cancer LNCaP-LN3 cells growing in culture as multicell spheroids expressed higher levels of E-cadherin and E-cadherin-associated beta-catenin than LNCaP-LN3 cells growing as monolayers. Treatment of cells with DOX downregulated PSA, E-cadherin, and keratin, and upregulated expression of vimentin and vascular endothelial growth factor (VEGF) mRNA. While treatment of cells with IFN-alpha did not alter gene expression, the addition of IFN-alpha to cultures treated with DOX produced synergistic toxicity and abrogated the changes in gene expression observed in cells treated with DOX alone. CONCLUSIONS: Treatment with IFN-alpha and DOX should be further explored as a therapeutic strategy for androgen-insensitive prostate cancer.

Androgens↗
PubMed2001

Promoter hypermethylation of MGMT is associated with protein loss in gastric carcinoma.

Aberrant methylation of CpG islands within promoter regions is associated with transcriptional inactivation of various tumor suppressor genes in neoplasms. Recently, O(6)-methylguanine-DNA methyltransferase, MGMT, was shown to be hypermethylated in certain carcinomas, resulting in loss of MGMT protein. We studied DNA methylation of CpG islands of the MGMT gene by methylation specific PCR in 26 gastric carcinoma tissues and 8 gastric carcinoma cell lines for comparison with levels of MGMT protein expression. In addition, we examined p53 mutation status in the same tissues by PCR-SSCP analysis for comparison with MGMT protein expression levels. In total, promoter hypermethylation of the MGMT gene was found in 8 (31%) of the 26 gastric carcinomas with reduced expression of MGMT protein, whereas the hypermethylation was not detected in the 18 carcinomas with non-reduced MGMT expression. MGMT protein expression levels were associated with promoter hypermethylation of MGMT (p = 0.0001; Mann-Whitney test); however, MGMT expression was not associated with p53 mutation status (p = 0.461; Mann-Whitney test). Among in gastric carcinoma cell lines, the TMK-1 cell line showed loss of the MGMT protein association with promoter hypermethylation and this loss was rectified by treatment with a demethylating agent, 5-Aza-2'-deoxycytidine. Our results suggest that transcriptional inactivation of MGMT by aberrant methylation of the promoter region may participate in carcinogenesis in the stomach.

Alleles↗
PubMed2001

Molecular diagnosis of gastric cancer: present and future.

Although histopathological diagnosis is extremely useful for the definitive as well as the supportive diagnosis of gastric cancer in clinical practice, it is limited in certain respects. Over the past 15 years, integrated research in molecular pathology has clarified the details of genetic and epigenetic abnormalities of cancer-related genes in the course of the development and progression of gastric cancer. These abnormalities, which include telomerase activation, genetic instability, and abnormalities in oncogenes, tumor suppressor genes, cell-cycle regulators, cell adhesion molecules, and DNA repair genes, could be effective markers in the molecular diagnosis of gastric cancer. It is possible that the molecular analysis of these alterations in histopathology specimens may overcome deficiencies in diagnoses that depend only on histomorphology, and, consequently, we may be able to improve the differential diagnosis of cancer, obtain information on the grade of malignancy, and identify patients at high risk of developing multiple primary cancers. In Hiroshima, we have established a system of molecular-pathological diagnosis as a routine service; about 5,000 lesions of the stomach have been subjected to this diagnosis, and much useful information has been obtained. In the near future, genetic analysis by means of DNA microarray may become routine in the diagnosis of gastric cancer. Genetic analysis of histopathology specimens may make clear the characteristics of individual cancers; indicating the common and specific features of molecular pathogenesis that may be directly connected with gene therapy or molecular-targeted therapy. By analyzing the relationship between single-nucleotide polymorphisms and cancer susceptibility, we will be able to obtain information on cancer prevention from histopathology samples.

Adenocarcinoma↗
PubMed2001

Pleomorphic adenoma of the parotid gland with extensive bone formation.

We report an unusual case of pleomorphic adenoma with extensive bone formation, occurring in the parotid gland of a 58-year-old Japanese man. The tumor was a well-circumscribed mass that measured 20 x 20 x 15 mm and contained extensive bone formation. Histologically, most of the tumor was composed of bone and chondroid tissues. The bone formation with a marrow-like structure occupied half the volume of the tumor. The chondroid tissues merged continuously into bone tissues. The bone tissue seemed to be formed within areas of chondral tissue by a process of enchondral ossification. Except for the unusual amount of large bone formation, the tumor showed histology of pleomorphic adenoma, particularly at the periphery of the tumor. These histological findings suggest the possibility of extensive enchondral ossification in pleomorphic adenoma.

Adenoma, Pleomorphic↗
PubMed2001

Expression of Bub1 gene correlates with tumor proliferating activity in human gastric carcinomas.

Bub1 plays an important role at the spindle assembly checkpoint to prevent cell cycle progression following spindle damage. We examined the expression of human Bub1 mRNA in 20 gastric carcinoma tissues and corresponding nonneoplastic mucosas by reverse transcriptase-polymerase chain reaction and analyzed the relation with proliferative activity monitored by the expression of proliferating cell nuclear antigen (PCNA) on Western blotting as well as Ki-67 labeling index by immunohistochemistry. Increased expression of Bub1 mRNA was detected in 8 (40%) of the gastric carcinomas in comparison with their nonneoplastic counterparts, while 4 (20%) expressed Bub1 at lower levels. The expression of Bub1 mRNA was confirmed by in situ hybridization. The expression levels of Bub1 mRNA were well correlated with the levels of PCNA protein in 16 (80%) gastric carcinoma cases. The examination of Ki-67 labeling indices proved the close correlation between the expression levels of Bub1 and proliferating activity. These findings suggest that mRNA expression of human Bub1 gene is closely associated with the tumor-proliferating activity. Since genetic alterations of human Bub1 rarely occur in gastrointestinal cancers, the functional machinery of Bub1 to prevent cell cycle progression into anaphase might be well preserved in gastric carcinomas even with high proliferative activity.

Aged↗
PubMed2001

Interleukin-15 expression is associated with malignant potential in colon cancer cells.

Interleukin 15 (IL-15 mRNA expression was detected in human colorectal cancer cells (Colo320, WiDr, TCO and DLD1) by the reverse transcriptase-polymerase chain reaction (RT-PCR). Only Colo320 and WiDr cells secreted IL-15 culture medium. With IL-15 treatment, all cell lines grew at a rate of 120-180% of that of nontreated cells. A binding assay with (125)I-labeled IL-15 showed binding activity to IL-15 in Colo320 (K(d): 0.098 nM) cells. IL-15 also reversed the growth inhibition caused by serum starvation in Colo320 cells. IL-15-induced cell growth in regular and serum-free media was abrogated by anti-IL-15 antibody treatment in Colo320 cells. Moreover, IL-15 treatment reduced doxorubicin-induced cytostasis and cytolysis in Colo320 cells by 50%. The invasion capacity of IL-15-treated Colo320 cells was 5.3 times that of untreated cells. Immunoblotting showed that IL-15-treated Colo320 cells exhibited downregulation of p21Waf1 and Bax, and upregulation of Bcl-2, phospho-AKT, MMP9/MMP2, and VEGF. Finally, immunostaining of human colon cancer revealed that 33 (70%) of 47 Dukes' C cases showed IL-15 expression in cancer cells, whereas only 16% of Dukes' B cases did (p < 0.0001). IL-15 may play important roles in cell proliferation, invasion, and metastasis of human colorectal cancer.

Adenocarcinoma↗
PubMed2001

Expression of MRE11 complex (MRE11, RAD50, NBS1) and hRap1 and its relation with telomere regulation, telomerase activity in human gastric carcinomas.

The MRE11 complex (MRE11, RAD50, NBS1) are required for the repair of DNA double-strand breaks and have another important function in regulating telomere length. The silent information regulator (Sir) proteins required for telomere position effect also bind telomeres. hRap1 protein is a human ortholog of yeast Rap1 which regulates telomere length by interacting with TRF2 and is recruited to telomeres by TRF2. We examined the expression of the MRE11 complex (MRE11, RAD50, NBS1), Sir2 and hRAP1 in 20 gastric carcinomas by reverse transcription polymerase chain reaction and then analyzed the relation between telomerase activity and other telomerase components such as human telomerase reverse transcriptase (TERT), human telomerase RNA component (hTR), human telomerase-associated protein (TEP1), telomeric repeat binding factor 1 (TRF1), TRF2- and TRF1-interacting, ankyrin-related ADP-ribose polymerase (tankyrase) as well as TRF1-interacting nuclear protein 2 (TIN2). Of twenty gastric carcinomas examined, 13 (65%), 14 (70%), 16 (80%), 12 (60%) and 13 (65%) expressed MRE11, RAD50, NBS1, Sir2 and hRap1 at higher levels than corresponding nonneoplastic gastric mucosa, respectively. No obvious correlation was observed between MRE11 complex expression and telomerase activity or expression of TERT, hTR, TEP1, tankyrase and TIN2. Carcinomas with high TRF1 expression expressed significantly higher levels of MRE11 and RAD50 than those with low TRF1 expression (p < 0.05). On the other hand, carcinomas with high TRF2 expression expressed significantly higher levels of MRE11, NBS1 and hRap1 than those with low TRF2 expression (p < 0.05). These results suggest that gastric carcinomas with high TRF1 and TRF2 expression may need a large quantity of the MRE11 complex. Moreover, gastric carcinomas with high TRF1 expression may require a large quantity of hRap1.

Aged↗
PubMed2001

Induction of ductal and stromal hyperplasia by basic fibroblast growth factor produced by human pancreatic carcinoma.

A histopathology study of 22 pancreatic adenocarcinoma cases revealed that 13 of the patients presented with hyperplastic lesions (atypical and non-atypical hyperplasia, mucous cell hypertrophy, focal epithelial hyperplasia, and ductal papillary hyperplasia), and 9 exhibited fibrosis adjacent to the carcinoma. All lesions expressed high levels of epidermal growth factor receptor (EGF-R) (p<0.0001 and p=0.0008, respectively) as compared with normal ductal epithelium. Non-atypical and atypical hyperplastic lesions also had a higher proliferating cell nuclear antigen (PCNA) labeling index (p<0.001 and p=0.0008, respectively) than normal ductal epithelium. A gradient in PCNA+ nuclei was found in acinar cells adjacent to the tumors. In 16 cases with marked fibrosis, we observed a significant increase of PCNA+ nuclei in stromal fibroblasts (p=0.0041) and significant upregulation of basic fibroblast growth factor (bFGF) mRNA expression in adjacent tumor cells (p=0.0213). These data suggest that the production of bFGF by pancreatic cancer cells induces ductal and stromal hyperplasia of the pancreas.

Adenocarcinoma↗
PubMed2001

Expression of telomeric repeat binding factor 1 and 2 and TRF1-interacting nuclear protein 2 in human gastric carcinomas.

Telomeric repeat binding factor 1 (TRF1) and 2 (TRF2) may play key roles in the maintenance of telomere function. TRF1 negatively regulates telomere elongation, while TRF2 protects the chromosome ends by inhibiting end-to-end fusions. We examined the expression of TRF1 and TRF2 in 20 gastric carcinomas by reverse transcription polymerase chain reaction and then analyzed the relation with telomerase activity and other telomerase components such as human telomerase reverse transcriptase (TERT), human telomerase RNA component (hTR), human telomerase-associated protein (TEP1) and TRF1-interacting, ankyrin-related ADP-ribose polymerase (tankyrase) as well as TRF1-interacting nuclear protein 2 (TIN2). Of 20 gastric carcinomas examined, 10 (50%) and 12 (60%) expressed TRF1 and TRF2 at higher levels than did non-neoplastic mucosa, respectively. No obvious correlation was observed between TRF1 expression and telomerase activity or expression of TERT, hTR and TEP1. Carcinomas with high TRF1 expression expressed significantly higher levels of tankyrase and TIN2 than did those with low TRF2 expression (p<0.05). The telomerase activities and the levels of TERT, hTR and TEP1 showed tendency to be lower in tumors expressing TRF1 at low levels, although it was not significant. On the other hand, carcinomas with short telomere length (shorter than 2 Kbp) expressed significantly stronger telomerase activities and higher TRF1 expression (p<0.05) and tended to express TRF2 and TIN2 at higher levels than those with long telomere length. The results suggest that gastric carcinomas with short telomeres need high levels of telomerase activity and large quantity of TRFs and TIN2, whereas those with long telomeres do not require high levels of telomerase activity and telomere associated proteins.

Aged↗