Biomedical subjects

S Takao

Publications and source records attributed to S Takao.

At least 73 records · Page 4Linked to original sources

PubMed1999

Multidrug resistance and the lung resistance-related protein in human colon carcinoma SW-620 cells.

BACKGROUND: Lung resistance-related protein (LRP), the major vault protein in humans, is sometimes overexpressed in multidrug-resistant cells. Because cells transfected with the LRP gene did not express the multidrug-resistant phenotype, we investigated whether LRP is involved in multidrug resistance. METHODS: SW-620 cells, a human colon carcinoma cell line, alone or transfected with an expression vector carrying a LRP-specific ribozyme or with an empty vector, were treated with sodium butyrate to induce differentiation. Expression of P-glycoprotein, multidrug resistance protein, and LRP in the cells was examined by northern and western blotting, and the efflux of doxorubicin in the cells or isolated nuclei was examined by fluorescence microscopy. RESULTS: A 2-week treatment with sodium butyrate induced LRP and conferred resistance to doxorubicin, vincristine, etoposide, gramicidin D, and paclitaxel (Taxol) in SW-620 cells. Insertion of either of two LRP-specific ribozymes into SW-620 cells inhibited these activities. Levels of drugs accumulating in the cells were not decreased by sodium butyrate, suggesting that the adenosine triphosphate-binding cassette transporter is not involved in sodium butyrate-induced multidrug resistance. Doxorubicin was mainly located in the nuclei of untreated cells and in the cytoplasm of sodium butyrate-treated cells. Isolated nuclei from untreated cells or sodium butyrate-treated cells incubated with anti-LRP polyclonal antibodies contained more doxorubicin than the nuclei of sodium butyrate-treated cells alone. Efflux of doxorubicin was greater from the nuclei of sodium butyrate-treated cells than the nuclei of untreated cells or of sodium butyrate-treated cells transfected with a LRP-specific ribozyme and was inhibited by an anti-LRP polyclonal antibody. CONCLUSIONS: LRP is involved in resistance to doxorubicin, vincristine, etoposide, paclitaxel, and gramicidin D and has an important role in the transport of doxorubicin from the nucleus to the cytoplasm.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1999

Postoperative prediction of and strategy for metastatic recurrent hepatocellular carcinoma according to histologic activity of hepatitis.

BACKGROUND: The hepatitis activity index (HAI) score describes the histologic status of accompanying chronic hepatitis and was established by pathologists. The aim of this study was twofold: 1) to investigate the correlation between intrahepatic metastatic recurrence (IM) and the HAI score of the noncancerous region of the liver and 2) to estimate the usefulness of postoperative preventive chemotherapy in patients with hepatocellular carcinoma (HCC). METHODS: The study included 158 consecutive patients who underwent curative resection for HCC and had been observed for > 1 year. Based on the HAI scores of the noncancerous region the patients were classified into 3 groups: those with mild hepatitis (n = 33) (i.e., with HAI scores of 0-5), those with moderate hepatitis (n = 77) (with HAI scores of 6-9), and those with severe hepatitis (n = 48) (those with HAI scores of > or = 10). In addition, a prospective randomized trial of postoperative adjuvant chemotherapy was performed for 21 patients with moderate hepatitis. RESULTS: The patients in the moderate hepatitis group were found to be at higher risk for IM recurrence within 2 years after HCC resection compared with those patients in the mild (P = 0.05) and severe (P < 0.01) hepatitis groups. The incidences of more than two tumors and portal vein involvement in patients with moderate hepatitis were much higher than in those patients with mild or severe hepatitis. Multivariate analysis showed that intraoperative bleeding volume, the number of nodules, portal vein involvement, and moderate hepatitis were independent predictive factors for IM recurrence free survival. Ten patients with moderate hepatitis had received postoperative intrahepatic arterial chemotherapy (2-3 courses with a maximum dose of 80 mg of cisplatin and 10 mg of mitomycin C at 1-month intervals) for the last 3 years. Although the number of patients was small, the therapy improved the disease free survival rate significantly compared with 11 patients who received no therapy. CONCLUSIONS: The patients with moderate hepatitis (HAI score of 6-9) had the highest rate of IM recurrence among the three HAI groups. Postoperative hepatic arterial chemotherapy may be useful in improving the rate of disease free survival after surgery among these patients.

Aged↗

PubMed1999

Thymidine phosphorylase in human esophageal squamous cell carcinoma.

BACKGROUND: Experimental evidence has shown that thymidine phosphorylase (dThdPase) is identical to platelet-derived endothelial cell growth factor (PD-ECGF) and has angiogenic activity. The enzymatic activity of dThdPase was needed for the angiogenesis by the enzyme. These observations were catalysts for the current study. METHODS: The authors examined retrospectively the expression of the angiogenic factor dThdPase in 163 primary esophageal squamous cell carcinomas and its association with angiogenesis and clinicopathologic findings. To determine whether dThdPase expression was a prognostic factor after adjustment for the established prognostic factors and microvessel count, the authors conducted a survival analysis using the Cox proportional hazards model. RESULTS: dThdPase was expressed significantly more frequently (P < 0.001) in esophageal carcinomas (83 of 163, 50.9%) than in adjacent nonneoplastic esophageal tissue samples (20 of 163, 12.3%). Microvessel counts were significantly higher (P < 0.001) in dThdPase positive carcinomas (18.3+/-6.2) than in dThdPase negative carcinomas (8.2+/-7.5). Significant correlations were observed between dThdPase expression and numerous clinicopathologic findings, including pT, pN, pM categories; lymphatic invasion; venous invasion; and residual tumors. Prognostic variables studied using a Cox hazard regression model confirmed that dThdPase expression was an independent prognostic factor in esophageal squamous cell carcinoma, although pN category was the best predictor of patient survival. CONCLUSIONS: This study indicated that in esophageal squamous cell carcinoma, dThdPase expression is associated with angiogenesis and is an unfavorable prognostic factor. These findings implied that the inhibition of dThdPase would improve the prognoses of some patients with dThdPase positive esophageal tumors.

Aged↗

PubMed1999

Molecular detection of circulating cancer cells during surgery in patients with biliary-pancreatic cancer.

BACKGROUND: It remains unclear whether surgical treatment for biliary-pancreatic cancers provokes the hematogenous dissemination of cancer cells. The aim of this study was to detect circulating cancer cells in the blood stream before and during tumor resection for biliary-pancreatic cancer. METHODS: We analyzed blood samples obtained perioperatively from the portal vein, peripheral artery, and superior vena cava, using a carcinoembryonic antigen (CEA)-specific nested reverse transcriptase-polymerase chain reaction. RESULTS: CEA-mRNA expression was detected in the blood of 21 (52.5%) of 40 patients with biliary-pancreatic cancer. The patients with detectable CEA-mRNA expression included 8 (42.1%) of 19 with bile duct cancers and 13 (61.9%) of 21 with pancreatic cancers. CEA-mRNA expression was not detected in blood obtained from 15 healthy volunteers and 15 patients with benign disease. The positive rate of CEA-mRNA of advanced clinical stage (TNM pStage III and IV) showed higher than that of early stage (pStage I and II; P <0.05). Tumor resection increased significantly the positive rates of CEA-mRNA in the blood stream of three kinds of vessel. CONCLUSIONS: Surgical procedures provoke the hematogenous dissemination of cancer cells perioperatively. Therefore, new strategies during operations to prevent liver metastases are needed to improve the survival of patients with biliary-pancreatic cancer.

Bile Duct Neoplasms↗

PubMed1999

Liver metastases after curative resection in patients with distal bile duct cancer.

BACKGROUND: Curative resection cannot ensure long-term survival for patients with distal bile duct cancer. The aim of this study was to determine the most frequent mode of recurrence after curative resection and to analyse its risk factors. METHODS: Clinical details for 64 consecutive patients with distal bile duct cancer who underwent surgical resection between 1980 and 1997 were reviewed. Modes of recurrence and clinicopathological findings were analysed based on the residual tumour (R) classification. RESULTS: The overall actuarial 5-year survival rate was 32 per cent. Of 42 patients undergoing R0 resection 10 were alive at 5 years, of 17 having R1 resection one was alive at 5 years, and none of the five patients having R2 resection survived for 5 years (R0 versus R1, P = 0.02). In the R0 group, the incidence of liver recurrence (14 of 42 patients) was similar to that in the R1 resection group (six of 17), although there were fewer lymph node and peritoneal recurrences than in patients who had R1 resection (P < 0.05). The high-risk factor for liver metastasis was microscopic vascular involvement. Important factors for survival were lymph node metastasis, microscopic vascular involvement and age. In addition, microscopic vascular involvement was the only independent factor for survival in the R0 group. CONCLUSION: R0 resection provided significant survival benefit but had no effect on liver recurrence. Therefore, new agents or strategies to prevent liver metastasis are necessary for improvement of survival.

Adult↗

PubMed1999

Gene expression of gastric type mucin (MUC5AC) in pancreatic tumors: its relationship with the biological behavior of the tumor.

Previously it has been found that the MUC2 gene for intestinal type secretory mucin is highly expressed in intraductal papillary mucinous tumors (IPMT), which are characterized by non-invasive growth and a favorable outcome. In contrast, MUC2 mRNA is rarely expressed in invasive ductal carcinomas (IDC), which have poor outcomes. The gastric type secretory mucin, MUC5AC, is strongly expressed in the surface mucous cells of gastric mucosa. As both MUC2 and MUC5AC mucins share the characteristics of forming highly viscous gels, it is expected that not only MUC2 mucin expression but also MUC5AC mucin expression may be associated with a favorable prognosis in patients with pancreatic tumors. MUC5AC mucin gene expression was examined in 24 cases of IPMT and 38 cases of IDC by in situ hybridization using a digoxigenin-labeled oligonucleotide. The results were compared with MUC2 mucin gene expression. Neither MUC5AC mRNA nor MUC2 mRNA was detected in normal pancreatic tissues. MUC5AC mRNA was expressed in 20 of 24 cases of IPMT (83%) and in five of 38 cases of IDC (13%). In contrast, MUC2 mRNA was expressed in 14 of 24 cases of IPMT (58%) and in none of the 38 cases of IDC (0%). The expression rates of MUC5AC mRNA and MUC2 mRNA in IPMT were significantly higher than those in IDC (P< 0.001, respectively). Intraductal papillary mucinous tumors are characterized by three histological types: (i) villous dark cell type; (ii) papillary clear cell type; and (iii) compact cell type. The villous dark cell type generally expressed both MUC5AC+ and MUC2+ genes. Alternatively, the papillary clear cell type and the compact cell type usually showed MUC5AC+ and MUC2- expression. Patients with MUC5AC mRNA expression had a significantly better survival prognosis than those with no MUC5AC mRNA expression (P< 0.005). In conclusion, MUC5AC gene expression occurs in a majority of IPMT cases, even in those with no MUC2 production. MUC5AC expression can be

Adenocarcinoma, Mucinous↗

PubMed1999

Sarcomatoid carcinoma of the pancreas: a case report with immunohistochemical study.

Sarcomatoid carcinoma of the pancreas is an uncommon neoplasm. The immunohistochemical characteristics of this unique type of pancreatic tumor were studied. Histologically, there was diffuse proliferation of atypical spindle cells that had hyperchromatic, short, spindle-shaped nuclei and pale cytoplasm. A few tiny foci of small tubular structures were seen in connection with the atypical spindle-shaped cells. Immunohistochemical examination showed that the spindle cells were positive for epithelial cell markers (cytokeratin AE3, cytokeratin AE1, epithelial membrane antigen) and DF3 (MUC1 apomucin-related antigen (ARA)), and were negative for markers such as vimentin, desmin, neuron-specific enolase, and myoglobin. DF3 antigen is known to be expressed in invasive ductal carcinoma of the pancreas and liver, as well as of the breast. Other MUC1-ARA (MY.1E12, MUC1 glycoprotein, HMFG-1, HMFG-2) and anti-CA19-9 were also detected in the present case. Thus, this tumor was diagnosed as anaplastic carcinoma (sarcomatoid carcinoma).

Aged↗

PubMed1999

Assessment of cervical lymph node metastasis in esophageal carcinoma using ultrasonography.

OBJECTIVE: To evaluate the efficacy of ultrasonography for the diagnosis of cervical lymph node metastasis in esophageal carcinoma. SUMMARY BACKGROUND DATA: Ultrasound (US) examination is useful for diagnosing lymph node metastasis. However, few reports have examined its role in the decision to perform cervical lymph node dissection in esophageal carcinoma. METHODS: Ultrasound examination was performed to evaluate cervical lymph node metastasis in 519 patients with esophageal carcinoma. The patients were divided into 5 groups according to treatment received: group 1, 153 patients who underwent curative resection of primary tumor by right thoracotomy and complete bilateral cervical lymphadenectomy; group 2, 112 patients who underwent curative resection of primary tumor by right thoracotomy but without cervical lymphadenectomy; group 3, 78 patients who underwent esophagectomy by left thoracotomy or blunt dissection with or without removal of cervical lymph nodes; group 4, 76 patients with palliative resection without cervical lymphadenectomy; and group 5, 100 patients without any surgical treatment. US diagnosis was compared with histologic findings or cervical lymph node recurrence. RESULTS: Lymph node metastasis was detected in 30.8% of patients (160/519). The sensitivity, specificity, and accuracy of US diagnosis in group 1 were 74.5%, 94.1%, and 87.6%, respectively. Cervical lymph node recurrence was seen in 7 patients (4.6%) in group 1, in 4 patients (3.6%) in group 2, and 3 patients (3.8%) in group 3. Although the incidence of cervical lymph node metastasis as determined by US examination was high in groups 4 and 5, almost none of the patients died of cervical lymph node metastasis. CONCLUSIONS: Ultrasound examination plays a useful role in the decision to perform cervical lymph node dissection in patients with esophageal carcinoma, particularly in those with potentially curative dissection.

Esophageal Neoplasms↗

PubMed1999

Cooccurrence of reduced expression of alpha-catenin and overexpression of p53 is a predictor of lymph node metastasis in early gastric cancer.

BACKGROUND AND OBJECTIVES: Even though the pathological background contributes to lymph node metastasis, the biological characteristics of tumors have also gained wide attention. In this study, the expression of the cadherin-catenin complex and p53 was studied in early gastric cancer. Their correlation with lymph node metastasis and the predictability of lymph node metastases, by combining these factors, were also discussed. METHODS: One hundred and one specimens obtained from surgery were studied by immunohistochemistry using monoclonal anti-E-cadherin, anti-alpha-catenin and anti-p53 antibodies. RESULTS: Expression of E-cadherin and alpha-catenin was reduced in 50.5 and 64.4%, respectively. p53 protein staining was positive in 29.7%. There was a significant correlation between E-cadherin and alpha-catenin expression, but no correlation was found between p53 expression and E-cadherin or alpha-catenin expression. A reduction in alpha-catenin expression and p53 overexpression correlated to lymph node metastases, respectively. Multivariate analysis showed that cooccurrence of reduced expression of alpha-catenin and overexpression of p53 was an independent factor indicating lymph node metastases. CONCLUSION: A study of both alpha-catenin and p53 expression may be helpful to predict lymph node metastases in early gastric cancer.

Adult↗

PubMed1999

Central control mechanisms of circulation in the medulla oblongata by nitric oxide.

Nitric oxide (NO) is involved in numerous physiological functions. Besides its role as an endothelium-dependent relaxing factor (EDRF), NO inhibits platelet aggregation, contributes to cytotoxicity against bacteria, is active in synaptic transmission within the brain, etc. NO synthase (NOS) is distributed in brain regions related to the regulation of cardiovascular functions. NO has been inferred not only to act directly on vascular vessels, but also to regulate circulation within the brain. In this review paper, we mainly consider the functions of NO in the cardiovascular center of the medulla oblongata. That is, we describe the anatomical distribution of NOS in the brain, effects of intravenous and intracerebroventricular administration of NOS inhibitors on the circulation, effects of microinjection of NO donors and NOS inhibitors into the nucleus tractus solitarius (NTS) and ventrolateral medulla (VLM), the results of electrophysiological studies on these areas, and finally, the data obtained by new molecular biological techniques.

Animals↗

PubMed1999

Hepatic metastasis of gastroenterological cancer: its tumor biology and oncological surgery.

Tumor angiogenesis and ability of basement membrane invasion for invasion of cancer cells into the tumor vessels and for circulating in the blood stream for hepatic metastasis are required. The molecular detection of cancer cells in the circulatory system strongly indicates the possibility of hepatic metastasis of a gastroenterological cancer. As an effect of the general anesthesia or the surgical procedure, a large amount of cancer cells in the tumor vessels may easily enter into the circulatory system at once from the primary tumor beds. Oncological surgeons should understand that the operation is not only the best treatment for gastroenterological cancer but also the crucial event of hepatic metastasis for cancer cells. Although further investigations are required to determine the relationship between circulating cancer cells and hepatic metastasis, at present, the most important issue to be addressed is the development of new strategies for the prevention of hepatic metastasis following the tumor resection in gastroenterological cancer.

Basement Membrane↗

PubMed1999

Expression of p21WAF1/Cip1 in the p53-dependent pathway is related to prognosis in patients with advanced esophageal carcinoma.

The proteins p53 and p21 are important components that regulate G1-S transition through the cell cycle. We immunohistochemically investigated p53 and p21 expression in 111 patients with esophageal squamous cell carcinoma. We also evaluated whether the expression of either of these proteins is a prognostic factor according to the p53-dependent and -independent pathways. The positive rates of p53 and p21 expression were 42.8 and 43.2%, respectively. Clinicopathological findings according to p53 and p21 expression did not differ significantly. The 5-year-survival rates between p21 positive and negative expression did not differ significantly in the p53-positive group. In the p53-negative group, the 5-year-survival rate of patients with p21-positive expression was 22.9%, which was significantly better than that of patients with p21-negative expression (12.7%; P<0.05). Multivariate analysis revealed that p21 expression in the p53-dependent pathway was an independent prognostic factor. Accordingly, the prognostic values of p21 expression between the p53-dependent and -independent pathways differed. Examination of p21-positive expression in the p53-dependent pathway will help to estimate the favorable prognosis of patients with advanced esophageal carcinoma.

Adult↗

PubMed1999

Phylogenic analysis of echovirus type 30 isolated from a large epidemic of aseptic meningitis in Japan during 1997-1998.

During 1997 to 1998, a nationwide epidemic of aseptic meningitis occurred in Japan. More than 4,500 isolates from patients with aseptic meningitis were identified as echovirus type 30. To investigate the character of these isolates, we examined the nucleotide sequences of thirty-seven geographical representatives and compared them with 50 strains isolated during the past 20 years. The phylogenic analysis used partial sequences from either the VP1 or VP4-VP2 region of the viral capsid. This analysis revealed that the isolates were divided into six genomic groups. All isolates identified during 1997-1998 belonged to only two genomic groups; these two groups are thought to be the causative viral agents involved in the recent epidemic.

Enterovirus B, Human↗

PubMed1998

Prevention of hypoxia-induced apoptosis by the angiogenic factor thymidine phosphorylase.

The angiogenic factor platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) is expressed at higher levels in a wide variety of solid tumors compared to adjacent normal tissues. Patients with PD-ECGF/TP-positive colon and esophageal tumors have a poorer prognosis than those with negative tumors. The expression of PD-ECGF/TP is a prognostic factor independent of microvessel density suggesting that TP has effects on tumor progression independent of its angiogenic activity. Evidence that hypoxia and apoptosis affect tumor growth prompted us to determine whether increased expression of PD-ECGF/TP prevents apoptosis induced by hypoxia. KB/TP cells transfected with a PD-ECGF/TP cDNA were resistant to hypoxia-induced apoptosis. Among the degradation products of thymidine produced by PD-ECGF/TP, 2-deoxy-D-ribose and thymine partially prevented hypoxia-induced apoptosis. The ability of 1 microM 2-deoxy-D-ribose in combination with the same concentration of thymine to prevent hypoxia-induced apoptosis was similar to that of the overexpressed TP in KB cells. A concentration of 1 microM 2-deoxy-L-ribose abrogated the effects of these degradation products of thymidine. These findings suggested that TP can confer resistance to apoptosis induced by hypoxia and the degradation products of thymidine are involved in this resistance. Expression of PD-ECGF/TP may play an important role in the progression of solid tumors, and inhibitors of TP and analogs of the degradation products of thymidine may suppress the growth of tumors by promoting apoptosis.

Angiogenesis Inducing Agents↗

PubMed1998

In vitro determination of basement membrane invasion predicts liver metastases in human gastrointestinal carcinoma.

We described previously (H. Imamura, et al., Cancer Res., 54: 3620-3624, 1994) a quantitative and reproducible 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for tumor cell invasiveness that uses a water-repellent, paraffin-treated Chemotaxicell chamber to produce a uniform Matrigel layer. In the present experiments, we studied 71 human gastrointestinal carcinomas, including 53 maintained as xenografts in nude mice and 18 fresh surgical specimens. We found a correlation between metastatic behavior and the percent invasion (PI) calculated from the MTT assay. Tumors producing liver metastases had a significantly higher PI than did tumors without liver metastases (P < 0.01), and seven of nine fresh tumors with a PI greater than 1.0 showed liver metastases within 2 years. No significant correlations were noted between the PI and clinicopathological factors. In the tumor xenografts, type IV collagenase activity was significantly higher in tumors with clinically evident liver metastases than in those without liver metastases (P < 0.05). Colorectal carcinomas with liver metastases and a high PI showed higher expression of matrix metalloproteinase 9 than matrix metalloproteinase 2 as assessed by gelatin zymography. Thus, the invasion-MTT assay is clinically useful for predicting liver metastases. Type IV collagenase plays an important role in the development of liver metastases from human gastrointestinal carcinoma.

Animals↗

PubMed1998

Design and testing of a new cisplatin form using a base material by combining poly-D,L-lactic acid and polyethylene glycol acid against peritoneal metastasis.

Microspheres containing cisplatin (CDDP) embedded in poly-d,l-lactic acid (PLA) and polyethylene glycol acid (CDDP-PPMS) were developed to improve treatment of malignant effusions. In vitro studies demonstrated that CDDP was released continuously for more than 4 weeks from CDDP-PPMS without initial burst. CDDP-PPMS was compared with CDDP aqueous solution (CDDP-SOL) by i.p. administration in rats for 1) tissue distribution, 2) toxicity and 3) therapeutic effects against Yoshida sarcoma. We found that the CDDP concentration in the omentum was maintained at a higher level than in the CDDP-SOL group, while the particles of CDDP-PPMS were observed in the stomata of the omentum by electron microscopy. Concentrations of CDDP in the lung, liver, kidney and blood were lower in the CDDP-PPMS group than in the CDDP-SOL group. All rats given CDDP-PPMS containing < or = 28 mg/kg were alive, whereas in the CDDP-SOL group, all rats given > or = 16 mg/kg died from side effects. The LD50 of CDDP-PPMS and CDDP-SOL were 32.8 and 14.8 mg/kg, respectively. The survival of rats with peritoneal metastasis was better in the CDDP-PPMS group than in the CDDP-SOL group.

Animals↗

PubMed1998

A subcloned human esophageal squamous cell carcinoma cell line with low thrombomodulin expression showed increased invasiveness compared with a high thrombomodulin-expressing clone--thrombomodulin as a possible candidate for an adhesion molecule of squamous cell carcinoma.

Thrombomodulin (TM) is an endothelial cell surface glycoprotein which converts thrombin from a procoagulant protease to an anticoagulant. We have previously reported that TM is a useful marker for immunohistochemical diagnosis of angiogenic tumors and also have reported that TM is expressed on squamous cell carcinoma (SCC) of the human esophagus. In addition, the expression of TM is significantly decreased in metastatic foci in lymph nodes compared with that in primary lesions. In order to reveal the biological significance of TM in SCC, we subcloned and established two different cell lines, i.e. TM-high-expressing (TE3HTM) cells and TM-low-expressing (TE3LTM) cells, from a human SCC cell line, TE3, using fluorescence-activated cell sorter (FACS) and examined the biological characteristics of these variant cell lines. These tumor cells revealed very similar morphological figures in ordinary cultured conditions and showed almost equal growth rates under various cultured conditions. By the invasion assay of these tumor cells using matrigel, we found that TE3LTM cells showed significantly increased invasive ability compared with that of TE3HTM cells. Characteristic intercellular localization of TM and a different manner of invasiveness between TE3LTM cells and TE3HTM cells suggest that TM may act as a cell-to-cell interaction molecule.

Carcinoma, Squamous Cell↗

PubMed1998

The expression of cadherin-catenin complex in association with the clinicopathologic features of early gastric cancer.

Although impaired expression of E-cadherin (E-cad) is frequently observed in tumors with aggressive histopathologic characteristics, the correlation between alpha-catenin (alpha-cat) expression and the clinicopathologic features of early gastric cancer have not been fully examined. In this study, we evaluated the expression of E-cad and alpha-cat by early gastric carcinomas, and examined the relationships between this expression and various clinicopathologic characteristics. A total of 69 specimens obtained from surgery were studied by immunohistochemistry. Reduced expression of E-cad and alpha-cat were found in 53.6% and 65.2% of the tumors, respectively, and a significant correlation was observed between the decreased expression of E-cad or alpha-cat and tumor histology, the quantity of stroma, and the infiltration pattern of the tumor. The reduced expression of alpha-cat correlated more strongly with these features than E-cadherin expression. Furthermore, alpha-cat expression was also related to the lymph node metastasis of tumors. The expression of E-cad or alpha-cat in the primary tumor was consistent with the expression of tumor cells that invaded the lymphatic vessels, but discordant with staining in the metastasized lymph nodes. In some cases, as the tumor invaded deeper, the expression of E-cad or alpha-cat changed from preserved to reduced. Our observations suggest that the reduced expression of E-cad or alpha-cat may be involved in the initial steps leading to the invasion and metastasis of early gastric cancer.

Adult↗