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Biomedical subjects

W Yasui

Publications and source records attributed to W Yasui.

At least 145 records · Page 8Linked to original sources
PubMed1993

Interleukin 1 alpha acts as an autocrine growth stimulator for human gastric carcinoma cells.

The expression and effect of interleukin 1 alpha (IL-1 alpha) were examined in human gastric carcinoma cell lines to determine if IL-1 alpha acts as a growth stimulator for these cells. Six of 8 gastric carcinoma cell lines expressed IL-1 alpha mRNA at various levels. Among them, TMK-1 and MKN-7 cells secreted IL-1 alpha into the culture fluid, in an especially large amount by MKN-7 cells. Scatchard plot analysis of IL-1 alpha binding revealed that TMK-1 cells had only one type of high-affinity receptors, whereas MKN-7 cells had high- and low-affinity receptors. Cell growth and DNA synthesis of TMK-1 and MKN-7 cells were stimulated by IL-1 alpha, and those of MKN-7 were inhibited by addition of anti-IL-1 alpha antibody or IL-1 receptor antagonist. The expression of IL-1 alpha mRNA by these cell lines was induced by either IL-1 alpha, epidermal growth factor, or transforming growth factor alpha. On the other hand, IL-1 alpha increased the mRNA expression for transforming growth factor alpha and epidermal growth factor receptor. These findings indicate that IL-1 alpha is an autocrine growth stimulator for gastric carcinoma cells and the interaction with epidermal growth factor/transforming growth factor alpha/receptor system should be involved in the growth modulation by IL-1 alpha.

Cell Division↗
PubMed1993

Aberrant expression of c-met mRNA in human gastric carcinomas.

We examined mRNA expression for c-met encoding hepatocyte growth factor receptor in 8 gastric carcinoma cell lines and 31 surgically resected gastric carcinoma tissues by Northern-blot analysis. Two forms of the transcript, sized 7.0 kb and 6.0 kb, were found in gastric carcinomas. Transcripts of both sizes were detected at various levels in all the gastric carcinoma cell lines except the MKN-74 line, which expressed only the 7.0-kb form. Of the 31 gastric carcinomas, 15 (48%) over-expressed the 7.0-kb transcript when compared with non-neoplastic mucosa. The 6.0-kb transcript of the c-met gene was expressed at considerable levels in 52% of the gastric carcinoma tissues, whereas it was only slightly expressed in non-neoplastic mucosa of a small number of cases. An important finding was that expression of the 6.0-kb transcript was closely correlated with tumor staging, lymph-node metastasis and depth of tumor invasion. These results, overall, suggest that the 6.0-kb transcript of the c-met gene might participate in the development and progression of gastric carcinomas.

Blotting, Northern↗
PubMed1993

Expression of P-cadherin in gastric carcinomas and its reduction in tumor progression.

The expression of P-cadherin, one of the Ca(2+)-dependent cell-cell adhesion molecules, in human gastric carcinomas was examined by Northern blotting, Western blotting and immunohistochemistry. P-cadherin mRNA was expressed in all the gastric carcinoma tissues examined, whereas no message was detected in non-neoplastic mucosa. By Western-blot analysis, P-cadherin protein was expressed in 83% and 29% of the well-differentiated and poorly differentiated gastric adenocarcinomas, respectively, the incidence being significantly different. Immunohistochemically, P-cadherin immunoreactivity was localized on the cell surface or the cell-to-cell borders of well-differentiated adenocarcinomas. P-cadherin was not detected in Borrmann's type-4 or scirrhous carcinomas where the tumor cells proliferate diffusely with productive fibrosis. The level of P-cadherin expression in stage-2 carcinomas was significantly higher than in stage-I carcinomas. In the case of patients in stages 2 to 4, however, the level of P-cadherin expression decreased as the stage progressed, the difference between stages 2 and 3 and between stages 3 and 4 being significant. Our findings suggest that P-cadherin might play an important role in the development of well-differentiated gastric adenocarcinomas and the decreased expression of P-cadherin might be responsible for the infiltrative growth and progression of gastric carcinomas.

Cadherins↗
PubMed1993

Increased expression of p34cdc2 and its kinase activity in human gastric and colonic carcinomas.

We examined the expression of p34cdc2 and its kinase activity in human gastric and colonic carcinoma cell lines and carcinoma tissues and studied its relation with a tumor-suppressor gene product, p53. All the gastric and colonic cancer cell lines expressed p34cdc2 and showed its kinase activity at various levels. When the cells were arrested in mitotic metaphase by the use of nocodazole, p34cdc2 kinase activity was induced and p53 was apparently phosphorylated. Of 12 gastric carcinoma cases, 11 (91.7%) showed higher p34cdc2 kinase activity in tumor tissues than in corresponding non-neoplastic mucosa. The protein kinase activities in the individual cases were well correlated with the levels of p34cdc2 protein expression. A good correlation was also found between the expression of p34cdc2 and proliferating cell nuclear antigen (PCNA). Almost all the colonic carcinomas showed higher cdc2 kinase activity and increased p34 expression when compared with non-neoplastic mucosa. Interestingly, most of the gastric and colonic carcinomas having high cdc2 kinase activity expressed high levels of p53. These findings suggest that the increased p34cdc2 kinase activity might cause the development and proliferation of gastric and colonic carcinomas, partly through abnormal p53 accumulation.

Blotting, Western↗
PubMed1993

Expression of growth factors and their receptors in human esophageal carcinomas: regulation of expression by epidermal growth factor and transforming growth factor alpha.

The expression of mRNAs for epidermal growth factor (EGF), transforming growth factor alpha(TGF alpha), EGFR, platelet-derived growth factor (PDGF) A and B chain, PDGF receptor (PDGFR), transforming growth factor beta (TGF beta), erbB-2 and estrogen receptor (ER) genes was first examined in 6 human esophageal carcinoma cell lines, 6 xenoplanted and 15 surgically resected esophageal carcinomas. Secondly, the effect of EGF and TGF alpha on the expression of these genes by the TE-1 esophageal carcinoma cell line was investigated. The expression of EGF mRNA was detected in 8 (29.6%) of 27 tumors including the cell lines, whereas the TGF alpha and EGFR genes were expressed in 21 (77.8%) and 24 (88.9%) tumors respectively. PDGF B chain and PDGFR were detected in 18 (66.7%) and 20 (74.1%), respectively, and ER mRNA was observed in 16 (59.3%) tumors. Genes for PDGF A chain and TGF beta and the erbB-2 gene were commonly expressed. On the other hand, exogenous EGF and TGF alpha stimulated the expressions of fos and myc genes by TE-1 cells. The expression of mRNAs for TGF alpha, PDGF A and B chain and the erbB-2 genes was also increased after treatment with EGF. TGF alpha increased the accumulation of mRNAs for EGF, TGF alpha, EGFR, PDGF A and B chain and the erbB-2 gene. Moreover, the expression of mRNAs for interstitial collagenase, stromelysin and type IV collagenase was increased after EGF or TGF alpha treatment. These results indicate that EGF and TGF alpha may regulate the multi-growth-factor receptor expression and may play a central role for tumor invasion and metastasis as autocrine modulators for human esophageal carcinoma.

Adenocarcinoma↗
PubMed1993

Reduced expression of nm23 protein is associated with advanced tumor stage and distant metastases in human colorectal carcinomas.

The nm23 gene, which encodes nucleoside diphosphate (NDP) kinase, is proposed as a metastatic suppressor gene. Loss of heterozygosity (LOH), and the expression of the nm23 gene were examined on matched sets of primary tumors and lymph node as well as distant metastases from colorectal carcinomas. Three (15%) of the 20 informative specimens examined showed LOH for the nm23 locus. nm23 was expressed in all the carcinomas as well as in nonneoplastic colonic mucosa at the mRNA and protein levels. Most of the carcinomas expressed the nm23 transcript at higher levels than the corresponding nonneoplastic colonic mucosa. By Western blotting, the level of nm23 protein expression in the tumors showed an inverse correlation with the tumor stage. Furthermore, distant metastatic tumors in the liver and lung showed reduced nm23 immunoreactivity in comparison with their primary tumor, although nm23 immunoreactivity was the same in the primary tumors and in local lymph node metastases. These results suggest that decreased nm23 expression may be associated with distant metastatic spread.

Adenocarcinoma↗
PubMed1993

Expression of amphiregulin, a novel gene of the epidermal growth factor family, in human gastric carcinomas.

The expression of mRNA for amphiregulin (AR), a novel gene of the epidermal growth factor family, was examined in 8 human gastric carcinoma cell lines and 32 gastric carcinoma tissues as well as corresponding normal mucosa. Of the 8 gastric carcinoma cell lines, 7 expressed 1.4 kb AR mRNA at various levels. The expression of AR mRNA by TMK-1 and MKN-28 cells was increased by treatment with epidermal growth factor or transforming growth factor a. In surgical cases, all the gastric carcinoma tissues and their adjacent normal mucosa expressed AR mRNA. Interestingly, 20 (62.5%) out of 32 tumors expressed AR mRNA at higher levels than their corresponding normal mucosas (tumor/normal > or = 1.2). No obvious correlation was observed between the AR mRNA levels and the histological types or tumor staging of gastric carcinoma. Immunohistochemically, AR protein was localized to the cytoplasm and/or nucleus in tumor cells. These results suggest that AR produced by tumor cells may be involved in the pathogenesis and/or progression of human gastric carcinoma.

Adult↗
PubMed1993

Reduced expression of nm23 is associated with metastasis of human gastric carcinomas.

Reduced expression of nm23 gene is implicated in high metastatic potential in a variety of malignancies. To elucidate the role of nm23 in human gastric carcinomas, we examined loss of heterozygosity (LOH) of nm23 gene by Southern blotting, nm23 mRNA expression by Northern blotting and nm23 protein expression by Western blotting as well as immunohistochemistry in both primary and metastatic tumors. LOH of nm23 gene was found in 2 (8%) out of the 23 informative gastric carcinomas. Twenty-two (84%) out of the 26 cases expressed nm23 mRNA at higher levels in primary tumor tissue than in corresponding non-neoplastic mucosa. No obvious correlation was observed between clinico-pathological features and LOH of nm23 gene or nm23 mRNA expression. On the other hand, 52% of the gastric carcinomas showed reduction of nm23 immunoreactivity in the metastatic tumor of regional lymph nodes, as compared to the primary tumor. Interestingly, 71% of the gastric carcinomas showed weaker nm23 immunoreactivity in the liver metastasis than in the primary tumor. These results suggest that nm23 overexpression is linked with development of gastric carcinomas and the decrease in expression of nm23 participates in metastasis.

Gene Expression↗
PubMed1993

[Metastasis related genes and malignancy in human esophageal, gastric and colorectal cancers].

Alterations in multiple oncogenes and multiple tumor suppressor genes are observed in human gastro-intestinal cancer. Among them, the most frequently implicated in malignancy and metastasis of esophageal carcinoma may be amplification and overexpression of the human cyclin D gene. In gastric carcinoma, amplification and abnormal expression of the c-met gene encoding receptor for hepatocyte growth factor (HGF) may contribute to the tumor progression and metastasis. Interaction between cadherin in c-met overexpressed tumor cells and HGF from fibroblast may play an important role in morphogenesis of two histological types of stomach cancer. During stomach carcinogenesis the clone having critical p53 mutations may expand selectively to make up a finally advanced stage of malignancy and show metastasis. In colorectal cancer, loss of heterozygosity of the RB, p53 and DCC genes is frequently associated with liver metastasis. Overexpression of nm23 may participate in carcinogenesis and the reduction in nm23 expression is involved in metastasis in gastric and colorectal cancers.

Colorectal Neoplasms↗
PubMed1993

A case report of epithelioid leiomyosarcoma of transverse mesocolon: diagnosis and treatment.

A case of epithelioid leiomyosarcoma of the transverse mesocolon in a 45-year-old man was reported. The patient had a rapidly growing mass in the left upper quadrant. Ultrasonography, gastrointestinography, and abdominal computed tomography showed that the mass was separated from the pancreas, the gastrointestinal tract, and the retroperitoneal organs. Preoperatively the primary origin of this tumor was related to the transverse mesocolon. On laparotomy the tumor of 5cm by 6cm by 3cm in size was found in the anterior left of the transverse mesocolon and the mass was resected entirely. The patient is well 18 months after surgical treatment with no evidence of recurrence.

Humans↗
PubMed1993

Ossifying fibromyxoid tumor of soft parts: a case report.

A case of ossifying fibromyxoid tumor of soft tissue parts in the presacral region, which developed in a 46-year-old Japanese man is reported. The enucleated tumor was an encapsulated, elastic, hard mass measuring 2.5 x 2.2 x 1.4 cm. Microscopically, the tumor was characterized by foci of round to polygonal cells dispersed in a fibromyxoid matrix, containing varying amounts of collagen and osteoid tissue. At the marginal zone, the shell of bone and osteoid tissue with calcification separated the tumor from the surrounding tissues. Our patient is showing no evidence of recurrence after a one-year follow-up period. The findings are compatible with those proposed for ossifying fibromyxoid tumor of soft parts by Enzinger et al. in 1989. This tumor should be differentiated from cartilaginous, osteogenic and neural tumors.

Fibroma↗
PubMed1993

GC factor represses transcription of several growth factor/receptor genes and causes growth inhibition of human gastric carcinoma cell lines.

The GC factor (GCF) binds to specific GC-rich sequences in the epidermal growth factor receptor (EGFR) gene promoter and represses its transcription. In this study, by the use of GCF transfection, we examined whether GCF represses the gene expression of several other growth factors and receptors and causes growth inhibition of cancer cells. The transfection of GCF expression vector into gastric carcinoma cell lines (TMK-1 and MKN-28) decreased the mRNA levels of transforming growth factor (TGF) alpha, insulin-like growth factor II, and c-met. The reduction of TGF-alpha expression was confirmed at the protein level by enzyme-linked immunosorbent assay. Transfection of GCF expression vector interfered with the mRNA accumulation for EGFR and TGF-beta induced by epidermal growth factor in gastric carcinoma cell lines. The carcinoma cells transfected with GCF expression vector did not grow in a serum-free medium, whereas the control cells did grow under serum-free conditions. When the growth of the gastric carcinoma cell lines was studied in nude mice, GCF-transfected carcinoma cells showed a significantly slower growth compared to the control tumor. Transient cotransfection analysis with NIH3T3 cells revealed that GCF repressed the promoter activity of TGF-alpha in addition to EGFR. These findings indicate that GCF negatively regulates gene expression of not only the EGFR but also several other growth factor and receptor genes and can inhibit the growth of gastric carcinomas in immunodeficient mice.

Animals↗
PubMed1992

The level of a transcription factor Sp1 is correlated with the expression of EGF receptor in human gastric carcinomas.

The expression of the transcription factor Sp1 and EGF receptor (EGFR) was examined on human gastric carcinoma cell lines and gastric carcinoma tissues as well as corresponding normal mucosa in order to clarify the mechanism of overexpression of EGFR gene without gene amplification. All 7 carcinoma cell lines expressed Sp1 mRNA, the levels of which were closely correlated with the expression of EGFR mRNA except for one cell line. The gel retardation analysis revealed that the levels of Sp1 mRNA were parallel to its DNA binding activities. In 18 surgical cases, 12 tumors expressed Sp1 mRNA at higher levels than normal mucosa. The cases with overexpression of Sp1 showed the high level of EGFR mRNA. These results suggest that overexpression of Sp1 in tumor cells may induce overexpression of EGFR without gene amplification in human gastric carcinomas.

Adult↗
PubMed1992

Frequent amplification of the c-met gene in scirrhous type stomach cancer.

Amplification of the c-met gene, that encodes hepatocyte growth factor receptor, was examined on human esophageal, gastric and colorectal carcinomas. Six (55%) of the 11 gastric carcinoma cell lines and 15 (23%) of the 64 advanced gastric carcinomas showed the c-met gene amplification. Among them, c-met amplification was detected in 5 gastric cancer cell lines, derived from scirrhous gastric carcinoma and in 5 (38%) of 13 scirrhous gastric carcinoma tissues. Furthermore, patients of gastric carcinoma with c-met amplification showed significantly advanced tumor stage and poorer prognosis than those without the amplification. Conversely, no amplification was detected in any of the esophageal and colorectal carcinoma cell lines as well as carcinoma tissues except one colonic carcinoma. These results overall suggest that amplification of the c-met gene might participate in carcinogenesis and progression of stomach cancer, especially scirrhous type stomach carcinoma.

Adenocarcinoma, Scirrhous↗
PubMed1992

Growth inhibition of transforming growth factor beta on human gastric carcinoma cells: receptor and postreceptor signaling.

The effect of transforming growth factor beta (TGF-beta) on human gastric carcinoma cell lines was examined. Cell growth and DNA synthesis of TMK-1 were inhibited by TGF-beta, whereas MKN-28 presented no response to TGF-beta. Scatchard plot analysis of TGF-beta binding showed that TMK-1 had a relatively small number of high-affinity receptors, whereas MKN-28 had a large number of low-affinity receptors. By affinity labeling, only the type I receptor (Mr 65,000) for TGF-beta was detected in TMK-1, while three types of receptors, type I, type II (Mr 85,000-95,000), and type III (Mr 250,000-350,000), for TGF-beta were present in MKN-28. TGF-beta treatment reduced p34cdc-2 kinase activity and the level of phosphorylation of retinoblastoma protein in TMK-1, whereas it did not affect them in MKN-28. mRNAs for MYC and platelet-derived growth factor B chain were increased by treatment of TGF-beta on TMK-1. cAMP-responsive element binding activity was decreased by TGF-beta treatment in MKN-28 but not in TMK-1. This was closely correlated with protein kinase C activity. These results suggest that the type I receptor for TGF-beta in human gastric carcinoma cells may be mainly linked with the growth inhibition of TGF-beta by a decrease in retinoblastoma protein phosphorylation by p34cdc-2 without suppression of MYC expression. Conversely, TGF-beta may reduce protein kinase C activity and cAMP-responsive element binding activity in TGF-beta-resistant gastric carcinoma cells.

CDC2 Protein Kinase↗
PubMed1992

p53 point mutations in primary human gastric carcinomas.

p53 point mutations in primary gastric carcinomas were analyzed by performing cDNA deoxynucleotide sequencing of the gene. Out of 16, 9 (56.3%) primary gastric carcinoma cases, including early cancer, showed one or more p53 point mutations in their open-reading frame, and 4 out of 9 cases had a p53 point mutation within highly conserved domains. The characteristics of the p53 mutation spectrum observed in primary tumors were (a) frequent mutation at an A:T pair (50%, 7 out of 14 mutations), (b) high transversion incidence (29%, 4 out of 14 mutations), (c) no transition at CpG, and (d) no G:C to T:A transversion. Our results suggest that p53 mutation is a common event in gastric carcinoma occurring from the early stage of progression with its specific mutation spectrum.

Adult↗