Biomedical subjects

Tetsu Yamane

Publications and source records attributed to Tetsu Yamane.

10 recordsLinked to original sources

PubMed2006

Expression of aquaporin 3 (AQP3) in normal and neoplastic lung tissues.

Aquaporin 3 (AQP3) acts as the membrane channel of water and other small solutes and plays a major role in fluid homeostasis. To investigate the expression of AQP3 in normal and neoplastic lung tissues, we studied a series of 149 lung carcinoma tissues and 2 cell lines by immunohistochemistry, Western blotting, and reverse transcriptase-polymerase chain reaction. In normal lung tissues, immunohistochemical expression of AQP3 was demonstrated in bronchial basal cells, alveolar type II cells, bronchiolar epithelial cells, and secretory cells of submucosal glands. In lung carcinomas, AQP3 expression was observed in 59 (70.2%) of 84 adenocarcinomas. Squamous cell carcinoma and large cell carcinoma had rather low positive ratios (35.8% and 13.4%, respectively). No AQP3 expression was demonstrated in small cell carcinoma, pleomorphic carcinoma, or metastatic colon adenocarcinoma. In adenocarcinomas, AQP3 was detected in all tumors of bronchioloalveolar subtype. Papillary subtype also showed a higher positive ratio of AQP3 compared with that in acinar and solid with mucin subtypes. In addition, AQP3 expression was related to tumor differentiation and clinical stage in adenocarcinomas. Western blotting and reverse transcriptase-polymerase chain reaction analyses confirmed the expression of AQP3 protein and messenger RNA in cell lines and tissues of lung adenocarcinoma. We conclude that AQP3 is widely expressed in the normal respiratory tract and can play an important role in the maintenance of water homeostasis. In addition, lung carcinomas, especially adenocarcinomas, can produce AQP3, possibly in connection with their functional and/or biological nature, although the detailed mechanism of AQP3 expression in lung carcinomas remains to be clarified.

Adenocarcinoma↗

PubMed2006

Activation of EDTA-resistant gelatinases in malignant human tumors.

Among the many proteases associated with human cancer, seprase or fibroblast activation protein alpha, a type II transmembrane glycoprotein, has two types of EDTA-resistant protease activities: dipeptidyl peptidase and a 170-kDa gelatinase activity. To test if activation of gelatinases associated with seprase could be involved in malignant tumors, we used a mammalian expression system to generate a soluble recombinant seprase (r-seprase). In the presence of putative EDTA-sensitive activators, r-seprase was converted into 70- to 50-kDa shortened forms of seprase (s-seprase), which exhibited a 7-fold increase in gelatinase activity, whereas levels of dipeptidyl peptidase activity remained unchanged. In malignant human tumors, seprase is expressed predominantly in tumor cells as shown by in situ hybridization and immunohistochemistry. Proteins purified from experimental xenografts and malignant tumors using antibody- or lectin-affinity columns in the presence of 5 mmol/L EDTA were assayed for seprase activation in vivo. Seprase expression and activation occur most prevalently in ovarian carcinoma but were also detected in four other malignant tumor types, including adenocarcinoma of the colon and stomach, invasive ductal carcinoma of the breast, and malignant melanoma. Together, these data show that, in malignant tumors, seprase is proteolytically activated to confer its substrate specificity in collagen proteolysis and tumor invasion.

Animals↗

PubMed2006

Topoisomerase IIalpha gene amplification in gastric carcinomas: correlation with the HER2 gene. An immunohistochemical, immunoblotting, and multicolor fluorescence in situ hybridization study.

Topoisomerase IIalpha (topoIIalpha) is an enzyme required for DNA replication and a molecular target for drugs called anthracyclines. The topoIIalpha gene (TOP2A) is located close to the HER-2/neu oncogene (HER2). We assessed gastric cancers to (1) clarify the relationship between gene amplification and protein overexpression of topoIIalpha and HER2; (2) evaluate the correlation between gene amplification and protein overexpression of topoIIalpha; and (3) examine the relationship between the results of immunohistochemistry and Western blot analysis for topoIIalpha. In a combined analysis of immunohistochemistry and fluorescence in situ hybridization on 552 formalin-fixed and paraffin-embedded gastric cancer tissues, 38 cases were found to have HER2 amplification. Further examination by fluorescence in situ hybridization revealed amplification of TOP2A in 13 of the 38 cases. No aberrations in the TOP2A gene were observed in cases without HER2 overexpression, except for one containing a gene deletion. The TopoIIalpha protein-labeling index was not correlated with TOP2A amplification. Fluorescence in situ hybridization was performed on nuclear imprint specimens obtained from 9 cases using simultaneous probes for TOP2A, HER2, and centromere 17. Of these 9 cases, 3 displayed coamplification of TOP2A and HER2, and only 1 of the 3 cases revealed a high expression of topoIIalpha in Western blot. Although patients having gastric adenocarcinoma with TOP2A amplification could be considered suitable for clinical trials, information involving anthracycline therapy is not firmly understood in regards to the status of TOP2A amplification or protein overexpression. Therefore, results of the current study will provide further insight for the clinical application of anthracycline in gastric cancers.

Adenocarcinoma↗

PubMed2006

EGFR protein overexpression and gene amplification in squamous cell carcinomas of the esophagus.

Overexpression of epidermal growth factor receptor (EGFR) is observed in many cancers, sometimes accompanied by gene amplification. Recently, several clinical therapies targeting EGFR were developed, but the eligibility criteria for these therapies is not fully established. To develop such eligibility criteria for esophageal squamous cell carcinoma (ESCC), we sought to clarify: (i) the exact frequency of EGFR overexpression, (ii) the relationship between protein overexpression and gene amplification, (iii) the relationship between gene amplification and specific gene mutations and (iv) the correlation between the status of EGFR and clinical or pathological features. Immunohistochemistry revealed that EGFR protein is overexpressed in 53 (50%) of the 106 ESCC examined. Fluorescence in situ hybridization (FISH) indicated clear EGFR gene amplification in 15 of the 53 tumors, somewhat higher EGFR copy in 32 cases, and no increase in 6 cases. Gene amplification was significantly associated with high level overexpression. Direct sequencing of exons 19 and 21 of EGFR revealed no mutations in 15 tumors exhibiting gene amplification, and no mutations in 25 tumors not exhibiting gene amplification. Overexpression of EGFR was significantly correlated with depth of invasion of the tumor. In conclusion, anti-EGFR therapies may be appropriate for patients with ESCC. We assume that combined analyses by immunohistochemistry/FISH would clarify aberrations in protein and gene function, and could help to identify those patients who may benefit from anti-EGFR therapy.

Adult↗

PubMed2005

'Increased expression of seprase, a membrane-type serine protease, is associated with lymph node metastasis in human colorectal cancer'.

Seprase is a membrane-bound serine proteinase with gelatinase activity, which may be involved in cancer invasion and metastasis. We examined seprase expression in colorectal cancer specimens obtained from 109 patients. Seprase immunoreactivity was found in cancer cells and adjacent stromal cells. Immunoblotting showed higher levels of seprase protein in colorectal cancer tissue than in normal colorectal tissue. A semiquantitative assessment of the immunohistochemistry results revealed a significant correlation between seprase expression and lymph node metastasis. These results suggested that an abundant expression of seprase in colorectal cancer tissue is associated with lymph node metastasis.

Adult↗

PubMed2005

Establishment and partial characterization of five malignant glioma cell lines.

Five malignant glioma cell lines (YMG1, 2, 3, 4, and 5) were established from surgical specimens obtained from patients with glioblastoma or anaplastic astrocytoma, and these lines were partially characterized. Three glioma cell lines (YMG1, 3, and 5) were weakly positive for GFAP by Western blot analysis and two cell lines were negative. S-100 protein was positive in all glioma cell lines. The expression of p53, p16, p15, cyclin-dependent kinase 4 (CDK4), and EGF receptor (EGFR) proteins was examined by Western blotting. YMG1 and 2 cell lines showed accumulation of p53 protein and loss of p16 and p15 expression. YMG3 and 4 showed accumulation of p53 protein and expression of p16 and p15 proteins. YMG5 revealed weak expression of p53 protein, suggesting wild-type p53, and loss of p16 and p15 expression. All cell lines expressed various levels of CDK4 protein. YMG1, 2, and 3 showed higher EGFR protein expression and YMG4 and 5 showed lower EGFR expression compared to U251 glioblastoma cells, which express high levels of EGFR. Fluorescence in situ hybridization analysis for EGFR gene expression did not show any amplification in the glioma cell lines. Immunohistochemical studies revealed that the patterns of p53 and EGFR expressions in the original tumor tissues were mostly correlated with those in the malignant glioma cell lines. These results suggest that the characteristics of p53 and EGFR expression in the malignant glioma cell lines were passed over from the original tumor tissues. These newly established malignant glioma cell lines can be used for further analysis of the mechanisms of tumor growth and progression.

Adult↗

PubMed2004

The expression of a type II transmembrane serine protease (Seprase) in human gastric carcinoma.

OBJECTIVE: The invasion and metastasis of carcinoma cells require the proteolytic degradation of the extracellular matrix by various cell surface proteases. Among these, seprase is a type II transmembrane serine protease absent in normal tissues and it has been implicated in the invasion of the extracellular matrix by both tumor and stromal cells in human breast carcinoma and melanoma. In the present study, the expression of seprase mRNA, protein and its gelatin-degrading activity in human gastric carcinoma were examined to substantiate the potential role of seprase in gastric carcinoma invasion. METHODS: We have examined the seprase expression in human gastric carcinoma (n = 34) by RT-PCR, Western immunoblotting analysis, immunohistochemistry, and gelatin zymography. RESULTS: Immunoblotting analysis using mAb D8 directed against seprase showed that the carcinoma tissues in 26 out of 34 cases of gastric cancer expressed a dimeric form of seprase but their normal counterparts did not. Gelatin zymography confirmed that the isolated seprase exhibited the gelatin-degrading activity and was active. Seprase-expressing carcinoma tissues were more often found in the scirrhous type than in other types of gastric carcinoma. RT-PCR analysis showed that seprase mRNA was present in carcinoma tissues but not in normal tissues. Immunohistochemically, seprase was mainly located in gastric carcinoma cells, weakly in stromal cells and microvessel endothelial cells in the tumor nest, and none in normal cells. CONCLUSIONS: Our studies showed the unique expression and localization of seprase in the tumor and stromal cells within human gastric carcinoma but not in normal tissues, suggesting a role of seprase in the invasive and metastatic progression of gastric carcinoma.

Biomarkers, Tumor↗

PubMed2003

Seprase, a membrane-type serine protease, has different expression patterns in intestinal- and diffuse-type gastric cancer.

OBJECTIVE: Seprase is an integral membrane serine proteinase with gelatinase activity that may be involved in cancer invasion and metastasis. However, the pathophysiologic significance of its expression in gastric cancer tissue has not been fully elucidated. METHODS: Seprase expression and distribution in gastric cancer specimens obtained from 133 patients were examined by immunohistochemistry and immunoblotting. RESULTS: Immunohistochemistry showed that in intestinal-type cancer, which includes well and moderately differentiated adenocarcinoma, seprase immunoreactivity was mainly recognized in the moderately differentiated cells and not in the well differentiated cells. In the diffuse type, which includes poorly differentiated adenocarcinoma and signet ring cell carcinoma, seprase immunoreactivity was seen mainly in cells with poor cell-to-cell junctions. The reactive pattern in the cells was different between moderately differentiated adenocarcinoma and diffuse-type carcinoma. Besides the cytoplasm, the cell membrane also apparently reacted in the former, while only the cytoplasm reacted diffusely in the latter. Seprase immunoreactivity was also recognized in endothelial cells and stromal cells especially adjacent to tumor nests. The immunoreactivity of the stromal cells was more abundant in the intestinal type than in the diffuse type, and these stromal expressions of seprase in the intestinal type correlated with the liver (13/13 = 100% of cases with metastases) or lymph node metastases (33/34 = 97% of cases with metastases). Immunoblotting showed that the levels of seprase protein were higher in intestinal-type cancer than in diffuse-type cancer. CONCLUSION: These results suggested that there is a difference in seprase expression between intestinal- and diffuse-type gastric cancer; this difference may reflect distinct biological features of these types of cancer.

Aged↗

PubMed2002

Induction of human inhibitor of apoptosis protein-2 by shear stress in endothelial cells.

To disclose the anti-atherosclerotic mechanisms of steady laminar shear stress, we analyzed the expression of human inhibitor of apoptosis protein-2 (HIAP-2), whose gene was selected from a cDNA library of sheared endothelial cells (ECs), on ECs. HIAP-2 was dose-independently and time-dependently induced in ECs by shear stress, regulated at the transcriptional level. HIAP-2 expression was also identified in vivo. Shear stress-mediated inhibition of EC apoptosis was associated with the inhibition of caspase-3 activity, suggesting that the shear stress prevents EC apoptosis via negative regulation of caspase-3 by the increment of HIAP-2.

Animals↗

PubMed2002

Invasive ductal carcinoma of the breast associated with Poland's syndrome: report of a case.

We report herein a rare case of invasive ductal carcinoma of the breast associated with Poland's syndrome. The patient was a 59-year-old woman who was referred to our department after a nodule had been found in the upper outer portion of the left breast by a breast cancer screening program. On physical examination, marked hypoplasia of the right breast and upper limb was noted. Preoperative computed tomography also revealed a defect in the right pectoralis muscles. A quadrantectomy of the left breast with lymphadenectomy was subsequently performed and pathological examination of the resected specimen showed invasive ductal carcinoma. Her medical history revealed that her mother had attempted to abort the pregnancy around the fifth week of her gestation. The present case suggests that such an event during gestational development may be associated with congenital anomalies predisposing to malignant disorders.

Arm↗