Multiple early gastric stump carcinomas after gastrectomy for peptic ulcer

The remnant stomach after partial gastrectomy is considered to have a predilection for the development of primary gastric carcinoma. However, early gastric stump carcinomas are uncommon because the diagnosis of gastric stump carcinoma is more difficult than that of carcinoma in the intact stomach. Triple early gastric stump carcinomas, as in the present case, are exceedingly rare and may provide some clues for further investigation of carcinogenesis in the gastric stump. We studied about the histological appearance, genetic alterations (P-53 gene, c-erbB-2 gene and K-ras gene), and expression of tumor-associated antigens (carcinoembryonic antigen, carbohydrate antigen 19-9, and sialyl-Tn) in this rare case. The three carcinomas differed from each other histologically. With respect to genetic alterations, c-erbB-2 was amplified in one lesion, but no mutations of K-ras and P-53 gene were detected. The three carcinomas also differed from each other on the expression of tumor-associated antigens. In noncancerous mucosal epithelium at the anastomosis showing hyperplasia and cystic formation of glandular epithelial cells, no genetic alterations were detected, but sialyl-Tn and carbohydrate antigen 19-9 were expressed. These results suggest that there may be different processes of carcinogenesis of the three carcinomas even though they occurred under identical environmental conditions to those that have increased cancer risk.

[Correlation between pyrimidine nucleoside phosphorylase (PyNPase)/platelet-derived endothelial cell growth factor and histological prognostic factor, and influences of 5'-deoxy-5-fluorouridine (5'-DFUR) administration on PyNPase levels. 5'-DFUR Joint Research Group in the Osaka Area for Gastric Cancer]

PURPOSE

Pyrimidine nucleoside phosphorylase (PyNPase), among which thymidine phosphorylase (dThdPase) exists mainly in human tumor tissues, is an enzyme to convert 5'-deoxy-5-fluorouridine (5'-DFUR) to 5-fluorouracil. Recently, it was reported that dThdPase was identical to platelet-derived endothelial cell growth factor, angiogenetic factor. Therefore, we expect that there is possibility of dThdPase being a prognostic factor.

METHODS

We investigated for a possible correlation between PyNPase activities in tumor tissues and prognostic factors of histological findings, examined the influences of preoperative oral 5'-DFUR administration to PyNPase levels and investigated for a correlation between HPLC methods and ELISA methods in patients with gastric cancer.

RESULTS

Higher levels of PyNPase were observed in patients with advanced t,n,v, and ly factors. PyNPase levels decreased by 5'-DFUR in patients with differentiated cases. A high correlation was found between HPLC and ELISA methods.

CONCLUSION

This study suggests that we must investigate possibility of PyNPase being a prognostic factor in more detail.

p53 protein overexpression as a predictor of the response to chemotherapy in gastric cancer

This study was performed to evaluate p53 overexpression as a predictor of the response to chemotherapy of patients with gastric cancer. The subjects comprised 20 patients with Stage IV gastric cancer and three with locally recurrent lesions, all of whom were treated with 5-fluorouracil (5-FU) plus cisplatin (CDDP) for 4 weeks. Of the total 23 patients there were 10 responders; 2 showing complete response (CR) and 8, partial response (PR). Specimens obtained by endoscopic biopsy were immunohistochemically stained using anti-p53 protein and bcl-2 protein antibody. Of the 10 responders, 7 demonstrated negative p53 staining, and of the 13 nonresponders, 11 demonstrated positive p53 staining (P = 0.013). Tissue from 3 of the responders and 7 of the nonresponders that stained for bcl-2 were positive prior to chemotherapy; however, there was no association between bcl-2 staining and chemotherapeutic effect. In conclusion, immunohistochemical identification of p53 in pretreatment tissue may represent a useful predictor for chemotherapeutic outcome in patients with gastric cancer.

Changes in tumor marker levels as a predictor of chemotherapeutic effect in patients with gastric carcinoma

BACKGROUND

Evaluating chemotherapeutic effect in patients with gastric carcinoma sometimes is difficult. The authors investigated whether changes in the serum levels of three tumor markers can be used to predict the clinical outcome after chemotherapy.

METHODS

Thirty patients with advanced and recurrent gastric carcinoma were treated with continuous 5-fluorouracil and low dose cisplatin for 4 weeks. Thirteen patients were treated neoadjuvantly prior to gastrectomy. The serum levels of carcinoembryonic antigen, carbohydrate antigen 19-9, and sialyl-Tn antigen were measured prior to and after chemotherapy. Responders were defined as those in whom abnormal serum levels of all three markers decreased to at least 50% of the pretreatment values and remained stable for at least 1 month.

RESULTS

The tumor markers could be evaluated in 27 of 30 patients (90%). The median duration of survival for the 15 responders and 12 nonresponders was 17 months and 6 months, respectively. There was a significant difference in the median duration of survival between the responders and nonresponders using the log rank test (P=0.0005). In the patients who received neoadjuvant therapy, the eight responders had a significantly longer survival period than did the three nonresponders (P=0.018). Seven of the eight responders showed evidence of tumor destruction histologically whereas none of the three nonresponders did.

CONCLUSIONS

Changes in the serum levels of these tumor markers after chemotherapy may be an excellent prognostic indicator for patients with gastric carcinoma.

Serum soluble interleukin-2 receptor level as a prognostic indicator in gastric cancer

T lymphocytes, activated by interleukin 2 during an anti-tumour response, release soluble interleukin 2 receptors (sIL-2R) into the bloodstream. We analysed the prognostic value of the serum sIL-2R level in gastric cancer. Serum concentration of sIL-2R in 96 gastric cancer patients and 100 healthy control subjects' was measured by enzyme-linked immunosorbent assay. All survivors were followed for more than 50 months. Serum sIL-2R level was considered with respect to prognosis, clinicopathological factors, other tumour markers and peripheral blood cell count. Stage III and IV patients had significantly higher sIL-2R levels than lower stage patients and control subjects. Stage III and IV gastric cancer patients were divided into 'high' and 'low' slL-2R groups based upon the control subjects' serum sIL-2R mean value plus one standard deviation. The high group had a significantly worse prognosis than the low group, although clinicopathological features and treatments were similar. Multivariate analysis demonstrated that the serum sIL-2R level is an independent indicator. The sIL-2R level did not correlate with carbohydrate antigen 19-9, however it did correlate with carcinoembryonic antigen (r = 0.22) and with numbers of peripheral blood monocytes (r = 0.54). In conclusion, serum sIL-2R may predict the outcome of gastric cancer patients with stage III or IV disease.

[A cooperative study on concomitant with low-dose divided administration of cisplatin (CDDP) and sustained drip infusion of 5-fluorouracil (5-FU) for unresectable advanced gastric cancer. Osaka Cisplatin Gastric Cancer Study Group]

For patients with unresectable gastric cancer registered between July 1994 and September 1995, the following dosage regimen was examined: a drip infusion of cisplatin (CDDP) at 7 mg/m2/day for 5 consecutive days and 2-day withdrawal a week for 3 weeks with concomitant sustained drip infusion of 5-FU at 300 mg/m2/day for 21 days. The whole cycle was repeated again after 2-week withdrawal. The antitumor effect was seen in 39.4% among 33 cases. With respect to histological classification, there was no difference in appearance of the effect between the moderately differentiated type at 62.5% and the low-differentiated type at 42.9%. The cases which became resectable after the administration included those in which the tumor disappeared completely in the resected specimens. As adverse reactions encountered in the cases above Grade 3, anorexia, nausea and vomiting and diarrhea were seen as clinical symptoms in 10, 5.3 and 11.8%, respectively. As laboratory test values, decrease in hemoglobin, leukocytopenia and thrombocytopenia were seen in 16.7, 15.8 and 5%, respectively, while renal or liver dysfunction did not occur. This dosage regimen was considered useful for unresectable advanced gastric cancer, although myelosuppression should be watched carefully.

Establishment of lymph node metastatic model for human gastric cancer in nude mice and analysis of factors associated with metastasis

The actual mechanisms responsible for lymph node metastasis in gastric cancer are still unclear. To investigate the mechanisms of lymph node metastasis in gastric cancer, we established a lymph node metastatic model for human scirrhous gastric carcinoma. Lymph node metastasis had frequently developed after orthotopic implantation of OCUM-2M LN derived from a scirrhous gastric cancer cell line, OCUM-2M, which had low capacity for lymph node metastasis. We elucidated the different characteristics including binding ability, migratory capacity and immunoresponses induced by the cell surface molecules of these two cell lines. The binding ability to Matrigel and migratory capacity of OCUM-2M LN cells were significantly greater than those of OCUM-2M cells. On flow cytometric analysis, both OCUM-2M and OCUM-2M LN cells strongly expressed HLA-I (99.5 and 97.1%) and LFA-3 (76.6 and 99.2%) in level of expression between the two cell lines, but neither cell line expressed HLA-II (0.0 and 0.0%), B7-1 (0.0 and 0.0%) or B7-2 (0.4 and 0.3%). ICAM-1 expression in OCUM-2M LN cells was weaker (0.7%) than that in OCUM-2M cells (36.8%). Strong adhesiveness and cytotoxicity of mononuclear lymphocytes for OCUM-2M cells were observed in adhesion and cytotoxic assays, both of which were significantly decreased by the addition of anti-ICAM-1 antibodies. On the other hand, the adhesiveness and cytotoxicity of OCUM-2M LN cells were significantly less than those of OCUM-2M cells, and were not affected by the addition of anti-ICAM-1 antibodies. These findings suggest that decreased ICAM-1 expression in a new gastric cancer cell line with a high rate of lymph node metastasis may in turn decrease immune responses mediated through LFA-1-dependent effector cell adhesion, and that this escape from the immunosurveillance system may be one of the factors inducing lymph node metastasis. In conclusion, we established a gastric cancer cell line, OCUM-2M LN, with a high rate of lymph node metastasis. An in vivo lymph node-metastatic model with this cell line should be useful for analysing the mechanism and therapeutic approach of lymph node metastasis.

Adhesion polypeptides are useful for the prevention of peritoneal dissemination of gastric cancer

We examined the effect of adhesion polypeptides on the adhesion and invasiveness of gastric cancer cell lines. We previously reported the establishment of an extensively peritoneal-seeding cell line, OCUM-2MD3, from a poorly seeding human scirrhous gastric carcinoma cell line, OCUM-2M. Both alpha2beta1 and alpha3beta1 integrin expression was markedly increased on OCUM-2MD3 cells compared with OCUM-2M cells, and the ability of OCUM-2MD3 cells to bind to the extracellular matrix (ECM) was also significantly higher than that of OCUM-2M cells. The adhesion polypeptides, YIGSR and RGD, and two RGD derivatives significantly inhibited the adhesion of OCUM-2MD3 cells to the submesothelial ECM, while not inhibiting the adhesiveness of OCUM-2M cells and two well differentiated human gastric cell lines, MKN-28 and MKN-74. The YIGSR and RGD peptides also significantly inhibited the invasiveness of OCUM-2MD3 cells. The survival of nude mice with peritoneal dissemination given YIGSR sequence intraperitoneally was obviously longer than that of untreated mice. The survival of mice treated with RGD was also improved, and this effect was increased using the RGD derivatives, poly(CEMA-RGDS) and CM-chitin RGDS. These polypeptides appear to block the binding of integrins, which are expressed on OCUM-2MD3 cells, to the submesothelial ECM, and consequently inhibit peritoneal implantation. The peritoneal injection of adhesion polypeptides may be a new therapy against the dissemination of scirrhous gastric cancer, and may be useful for the prevention of dissemination in high-risk patients.

Diagnostic potential and pitfalls of ultrasound-guided fine-needle aspiration cytology for breast lesions

Ultrasound (US)-guided fine-needle aspiration cytology (FNAC) is now widely accepted as a diagnostic procedure for breast lesions. Along with its advantages, US-guided FNAC also has some pitfalls. The recognition of these pitfalls for this procedure is extremely important for the strict management of the disease. We retrospectively investigated the diagnostic potential and pitfalls of US-guided FNAC in the diagnosis of breast lesions. This study consisted of 348 aspirated samples from 274 breast tumors. The rate of sufficient aspirates was 74% after a single aspiration, while sufficient materials were finally obtained from 93% of the tumors by repeated aspirations. The rate was lower in tumors measuring less than 10 mm in diameter (62%), and in sclerosing adenosis (25%). The sensitivity of FNAC was 65%, the specificity was 75%, the border diagnosis rate was 18%, and the positive predictive value was 92%. The false-negative rate was higher in noninvasive carcinoma (45%). The border diagnosis rate was also higher in scirrhous carcinoma (29%). There were also five false-positive cases. Limited to nonpalpable lesions, the sufficient aspirates rate was 70% and the accuracy was 67%.

[p53 and Bax protein expression as predictor of chemotherapeutic effect in gastric carcinoma]

This study was performed to estimate p53 and Bax overexpression as a predictor of the response to chemotherapy of patients with gastric cancer. The subjects were 20 patients with stage IV gastric cancer and 3 with locally recurrent lesions treated with 5-fluorouracil (5-FU) and low-dose cisplatin (CDDP) for 4 weeks. Of the total 23 patients, there were 10 responders: 2 showing complete response (CR) and 8, partial response (PR). Carcinoma biopsy specimens of all were obtained endoscopically with anti-p53 and anti-Bax antibodies. Of the 10 responders, 7 were in the negative p53 staining group, while of the 13 non-responders, 11 were in the positive p53 staining group (p = 0.013). But no correlation was demonstrated between the chemotherapeutic effect and Bax staining alone. Moreover, among the p-53-positive cases, the patients with Bax-negative tumors were all chemoresistant. Therefore, immunohistochemical identification of p-53 and Bax prior to chemotherapy may be a useful predictor for choice of non-responders to chemotherapy.

TGF-beta1 produced by gastric cancer cells affects mesothelial cell morphology in peritoneal dissemination

In vitro morphologic change of mesothelial cells was observed following the addition of serum-free conditioned medium (SF-CM) from peritoneal dissemination cell line OCUM-2MD3. The same morphologic change of mesothelial cells was observed following the addition of 10 ng/ml TGF-beta1, but not following the addition of b-FGF, IGF-I, VEGF or PDGF-AA. In the in vivo study, mesothelial cells of mice treated with SF-CM from OCUM-2MD3 and TGF- beta1 were separated from one another, resulting in exposure of the submesothelial connective tissue. The molecular size of the mesothelial morphology changing activity was estimated by running the SF-CM from OCUM-2MD3 through a gel filtration column TSK-gel G2000SW. The mesothelial morphology changing activity was recognized at positions equivalent of Mr 6, 500-30,000. 25 kDa TGF-beta1 was detected in the active fraction from the TSK-gel G2000SW column and the SF-CM of OCUM-2MD3 by Western blotting using a monoclonal antibody against TGF-beta1. These findings suggest that TGF-beta1 produced by gastric cancer cells changes the morphology of mesothelial cells and may thus be closely associated with peritoneal dissemination.

Cyclin D1 overexpression and prognosis in colorectal adenocarcinoma

Recently, it has been reported that cyclin D1 plays a major role in oncogenesis in various cancers; however, there have been few studies on the association of cyclin D1 overexpression and prognosis of patients with malignant tumors. We evaluated the prognostic significance of cyclin D1 overexpression in colorectal adenocarcinoma. One hundred twenty-three specimens resected from patients with colorectal adenocarcinomas were investigated by staining with a monoclonal antibody against cyclin D1. As a result, both overall survival and disease-free survival were significantly poorer in the patients with tumors strongly positive for cyclin D1 than in those with cyclin-D1-negative or weakly positive tumors. The 5-year survival rate of the patients with tumors strongly positive for cyclin D1 was 53.3%, while the 5-year survival rates of patients with cyclin-D1-negative and weakly positive tumors were 96.2 and 78.8%, respectively. Moreover, multivariate analysis indicated that cyclin D1 overexpression is an independent predictor of disease recurrence in our patients. In conclusion, cyclin D1 overexpression may be useful as a predictor of disease recurrence in colorectal adenocarcinoma.

Globotriaosyl ceramide and globoside as major glycolipid components of fibroblasts in scirrhous gastric carcinoma tissues

Scirrhous gastric cancer is characteristic in that cancer cells proliferate and invade with prominent fibrosis. To search for the expression of specific carbohydrate chains in scirrhous gastric cancer, we have examined the glycosphingolipid composition of scirrhous cancer tissues (n=10) in comparison with that of non-scirrhous cancer tissues (n=10) by means of two-dimensional thin layer chromatography, followed by fast atom bombardment mass spectrometry of the individual glycolipids and immunostaining analysis. The major neutral glycosphingolipids from scirrhous gastric cancer tissues were identified as ceramide monohexoside, ceramide dihexoside, globotriaosyl ceramide (Gb3) and globoside (Gb4), while the major acidic glycosphingolipids were II3 NeuAcalpha-LacCer, II3 NeuAcalpha2-LacCer and sulfatide. Relative concentrations of Gb3 and Gb4 in scirrhous gastric cancer tissues (Gb3 + Gb4 = 58%) were two times higher than those in non-scirrhous gastric cancer tissues (29%). Orthotopic fibroblasts cloned from scirrhous gastric cancer tissues showed similar high concentrations of Gb3 and Gb4 to scirrhous gastric cancer tissues. Furthermore, immunohistochemical study revealed that Gb3 and Gb4 were expressed intensely on the fibroblasts. On the other hand, analysis of glycosphingolipids in four scirrhous gastric cancer cell lines yielded the following results. i) The contents of Gb3 and Gb4 were low (6%), compared with orthotopic fibroblasts (62%). ii) Significant amounts of Le(a) (pentaglycosylceramide) and Le(b) (hexa- and heptaglycosylceramides), which could not be detected in scirrhous cancer tissues, were observed. The results show that the major neutral glycosphingolipids such as Gb3 and Gb4 of scirrhous gastric cancer tissues were derived from orthotopic fibroblasts and not from the cancer cells.

The antiproliferative effect of HGF on hepatoma cells involves induction of apoptosis with increase in intracellular polyamine concentration levels

Hepatocyte growth factor (HGF) induced apoptosis and decreased the DNA synthesis in Hep G2 cells. In the HGF group interleukin-1 converting enzyme, ornithine decarboxylase (ODC) activity and intracellular polyamine concentrations were increased compared to those of the control group. Administration of the ODC inhibitor decreased polyamine concentration, and inhibited apoptotic changes in the cells. These changes were reversed by exogenous addition of polyamine. These findings suggest that one of the mechanisms by which HGF exerts its antiproliferative effect is induction of apoptosis and that increase in intracellular polyamine concentration may be one of the triggers of cell death.

Expression of intercellular adhesion molecule-1 in invasive breast cancer reflects low growth potential, negative lymph node involvement, and good prognosis

To understand the role of intercellular adhesion molecule-1 (ICAM-1) in tumor progression in the host, we examined ICAM-1 expression in breast cancer by immunohistochemistry. This study included 274 female patients with invasive breast cancer, with a median follow-up of 98 months. The molecule was identified in formalin-fixed, paraffin-embedded primary tumors, and the relationship to clinicopathological factors and prognosis was analyzed. ICAM-1 expression occurred in 50.3% of patients. ICAM-1 expression had negative correlation to tumor size (P = 0.003), lymph node metastasis (P < 0.0001), tumor infiltration (P = 0.003), nuclear pleomorphism (P = 0.004), and nuclear grade (P = 0.042). Patients with ICAM-1-positive tumors had better relapse-free and overall survival than those with negative tumors (P < 0.0001 and P = 0.0003, respectively). These results suggest that expression of ICAM-1 on cancer cells might have a role as a suppressor of tumor progression under the host immune surveillance system.

Elevation in putrescine level and spermidine/spermine N1-acetyltransferase activity coincide with tumor development in 1, 2-dimethylhydrazine-induced rat colon

Spermidine/spermine N1-acetyltransferase (SSAT), rate-limiting enzyme of polyamine interconversion, has been demonstrated to play an important role in malignant transformation of cells. We examined the involvement of altered polyamine metabolism in the colonic carcinogenesis, using 1,2-dimethylhydrazine (DMH)-induced rat colon tumor model. Following findings were obtained: i) Ornithine decarboxylase demonstrated high activity from the early phase in colon mucosa, and increased significantly in tumors. ii) Spermidine and spermine levels gradually elevated in DMH-treated mucosa, while putrescine increased significantly in tumor tissues. iii) SSAT activity increased gradually in DMH-treated colon mucosa, which preceded elevation of tissue putrescine level, and coincided with tumor development. In conclusion, elevation of putrescine level and induction of SSAT activity are suggested to have a close association in colonic carcinogenesis.

F1 alpha: a novel mucin antigen associated with gastric carcinogenesis

In a previous study, we obtained a novel monoclonal antibody (F1 alpha-75) directed against a synthetic mucin antigen termed F1 alpha, and demonstrated that this antigen was expressed in a high percentage (80.2%; 89/111) of gastric carcinomas. In the present study, we compared the expression of F1 alpha with that of sialyl-Tn antigen, a mucin antigen similar to F1 alpha, in 54 human early gastric carcinomas, intestinal metaplasia and adenomatous polyps of the stomach to determine how differences in the expression of these antigens correlated with gastric carcinogenesis. The rate of expression of F1 alpha in early gastric carcinoma tissues, 81.5%, was higher than that of sialyl-Tn antigen, 57.4%. No correlation was found between the rate of expression and histological type, depth of cancerous invasion or lymph node metastasis. Sialyl-Tn antigen was extensively expressed in 77.5% of specimens of complete intestinal metaplasia and in 78.6% of those of incomplete intestinal metaplasia; however, the expression of F1 alpha in those specimens was rare and sporadic, with rates of only 25.0 and 27.7%, respectively. In adenomatous polyps, the rate of expression of F1 alpha is 6.25% and that of sialyl-Tn antigen is 43.8%. Our findings indicate that F1 alpha is a more specific antigen for gastric cancer than sialyl-Tn antigen, and that F1 alpha is an antigen associated with carcinogenesis of the stomach.

Combined analysis of vascular endothelial growth factor and platelet-derived endothelial cell growth factor expression in gastric carcinoma

Solid tumours require neovascularization for growth and metastasis. Both vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) are well-characterized inducers of angiogenesis. In this study we examined the expressions of these antigens and their relationship with microvessel density and also determined their prognostic significance. Ninety-five specimens resected from patients with gastric carcinoma were investigated using immunohistochemical methods. Microvessel density, determined by immunostaining for factor VIII-related antigen, was significantly higher in tumours that were both VEGF+ and PD-ECGF+ than in tumours that were both VEGF- and PD-ECGF-. According to prognosis, patients with VEGF+ tumours had a significantly worse prognosis than did those with VEGF- tumours. Although there was no significant correlation between PD-ECGF expression and prognosis, patients with PD-ECGF+ tumours tended to have a shorter survival than did those with PD-ECGF- tumours. Moreover, the frequency of hepatic recurrence was significantly higher in patients with tumours that were both VEGF-positive and PD-ECGF+ than in all other patients.

Combined analysis of p53 and vascular endothelial growth factor expression in colorectal carcinoma for determination of tumor vascularity and liver metastasis

Recent studies have demonstrated that the p53 tumor suppressor gene plays an important role in controlling tumor angiogenesis. We examined the expression of p53 and vascular endothelial growth factor (VEGF), a well-characterized angiogenic inducer, together with microvessel density to investigate the role of p53 in the regulation of angiogenesis and its clinical significance in human colorectal carcinoma. Surgically resected specimens of 163 colorectal carcinomas were studied by immunohistochemical staining for p53 protein, VEGF and factor VIII-related antigen. Positive p53 protein accumulation and VEGF expression was found in 41.7% and 49.1% of tumors, respectively. p53 and VEGF staining status was identical in 65.6% of tumors. The incidence of p53- or VEGF-positive tumors was significantly higher in patients with venous invasion and liver metastases than in those without. The microvessel count (MVC) in p53- or VEGF-positive tumors was significantly higher than that in negative tumors, and MVC in both p53- and VEGF-positive tumors was significantly higher than that in the other subgroups. Neither synchronous nor metachronous hepatic metastases were found in patients with p53- and VEGF-negative tumors, while 52.2% of patients with both-positive tumors had liver metastases and had a poorer prognosis than those with both-negative tumors. Our findings suggest the presence of a p53-VEGF pathway regulating tumor angiogenesis in human colorectal carcinoma. Combined analysis of p53 and VEGF expression might be useful for predicting the occurrence of liver metastasis in patients with this disease.

Combined analysis of p53 and vascular endothelial growth factor expression in colorectal carcinoma for determination of tumor vascularity and liver metastasis

Recent studies have demonstrated that the p53 tumor suppressor gene plays an important role in controlling tumor angiogenesis. We examined the expression of p53 and vascular endothelial growth factor (VEGF), a well-characterized angiogenic inducer, together with microvessel density to investigate the role of p53 in the regulation of angiogenesis and its clinical significance in human colorectal carcinoma. Surgically resected specimens of 163 colorectal carcinomas were studied by immunohistochemical staining for p53 protein, VEGF and factor VIII-related antigen. Positive p53 protein accumulation and VEGF expression was found in 41.7% and 49.1% of tumors, respectively. p53 and VEGF staining status was identical in 65.6% of tumors. The incidence of p53- or VEGF-positive tumors was significantly higher in patients with venous invasion and liver metastases than in those without. The microvessel count (MVC) in p53- or VEGF-positive tumors was significantly higher than that in negative tumors, and MVC in both p53- and VEGF-positive tumors was significantly higher than that in the other subgroups. Neither synchronous nor metachronous hepatic metastases were found in patients with p53- and VEGF-negative tumors, while 52.2% of patients with both-positive tumors had liver metastases and had a poorer prognosis than those with both-negative tumors. Our findings suggest the presence of a p53-VEGF pathway regulating tumor angiogenesis in human colorectal carcinoma. Combined analysis of p53 and VEGF expression might be useful for predicting the occurrence of liver metastasis in patients with this disease.

Combined analysis of vascular endothelial growth factor and platelet-derived endothelial cell growth factor expression in gastric carcinoma

Solid tumours require neovascularization for growth and metastasis. Both vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) are well-characterized inducers of angiogenesis. In this study we examined the expressions of these antigens and their relationship with microvessel density and also determined their prognostic significance. Ninety-five specimens resected from patients with gastric carcinoma were investigated using immunohistochemical methods. Microvessel density, determined by immunostaining for factor VIII-related antigen, was significantly higher in tumours that were both VEGF+ and PD-ECGF+ than in tumours that were both VEGF- and PD-ECGF-. According to prognosis, patients with VEGF+ tumours had a significantly worse prognosis than did those with VEGF- tumours. Although there was no significant correlation between PD-ECGF expression and prognosis, patients with PD-ECGF+ tumours tended to have a shorter survival than did those with PD-ECGF- tumours. Moreover, the frequency of hepatic recurrence was significantly higher in patients with tumours that were both VEGF-positive and PD-ECGF+ than in all other patients.

[Current status of low-dose CDDP. 5-FU therapy for solid malignant tumors--nationwide questionnaire survey]

A nation-wide questionnaire survey was undertaken concerning low-dose anticancer therapy of CDDP plus 5-FU, which involves (5-10 mg CDDP/body/day + 300-500 mg/body/day) for 4-6 weeks. Out of 1,525 cases from 130 institutions, 847 cases with evaluable lesions were collected from 79 institutions. The response rate was 56.4% in esophageal cancer, 34.3% in gastric cancer, 35.3% in colorectal cancer, 47.2% in liver cancer and 35.9% in lung cancer, respectively. Adverse effects were found to be fewer and compliance was much better than the conventional therapy. Such figures suggest that the present regimen may be more effective than any so far. Problems for medical administration such as unlicensed CDDP for colorectal cancer were pointed out, which hinder the forthcoming third phase study.

An experimental study of hepatic resection using an in situ hypothermic perfusion technique

BACKGROUND/AIMS

Recently, along with the progression of hepatic surgery, the in situ hypothermic perfusion technique has been used for major hepatic resection. The aim of this study was to elucidate the utility of the hypothermic perfusion technique in hepatic resection.

METHODOLOGY

Two experimental models: a Total Vascular Occlusion group (TVO) and a Total Vascular Occlusion under Hypothermic Perfusion group (HP) were utilized using adult mongrel dogs. An approximately 40-45% hepatic resection was performed under total vascular occlusion with a systemic and portal shunt. In the HP group, the liver was perfused through the portal vein with lactated ringer's solution at 4 degrees C. In the TVO group, hepatic resection was done without perfusion.

RESULTS

Serum AST and ALT levels after reperfusion were significantly increased in the TVO group. From the change of serum hyaluronic acid and xanthine oxidase activity, sinusoidal endothelial cell function was maintained in HP more than in TVO. The mean arterial pressure, portal venous pressure and portal venous blood flow were maintained in HP after reperfusion. Examination of vascular permeability using monastral blue showed that vascular permeability of the small intestine, lung and liver was clearly increased in TVO. Chemiluminescense intensity of the hepatic venous blood after reperfusion gradually increased only in TVO. In addition, the chemiluminescense intensity of the hepatic venous blood congested in the liver increased markedly as vascular occlusion continued in TVO. The hepatic venous blood serum congested in the liver induced morphological changes in the human umbilical vein endothelial cells and increased their permeability. The SDS-PAGE of the hepatic venous blood serum congested in the liver revealed several proteins between 37 and 42 KD.

CONCLUSION

The hypothermic perfusion technique in hepatic resection may be very useful in preserving the hepatocytes and sinusoidal endothelial cells and in maintaining stability of the systemic or hepatic circulation after reperfusion because of the cooling of the liver and the washing out of congested blood in the liver.

Experimental study of the effect of IL-6 on cancer cachexia

Several cytokines, including IL-1, TNF, LIF and IL-6 have recently been proposed as cachexia inducers. We experimentally examined the participation of cytokines, particularly, IL-6, in cancer cachexia using the human digestive cancer cell lines MKN 28, MKN 45, MKN 74, Kato-III, OCUM-2M (gastric cancer), SW1990, Panc-1 (pancreatic cancer), and OCUG (gallbladder cancer). A high level of IL-6 was detected in the OCUG culture medium. Nude mice bearing OCUG tumor had reduced body weight even when the tumor was relatively small. Loss of both muscle and adipose tissue, anemia, hypoglycemia, and a high serum level of human IL-6 were observed in these mice. However, body weight recovered rapidly to the level of that of nontumor-bearing mice after resection of OCUG tumor. Antihuman IL-6 but not anti-murine IL-6 receptor antibodies significantly suppressed the development of cachexia as measured by various indicators of cachexia including loss of both muscle and adipose tissue, anemia and hypoglycemia, as well as weight loss. These results suggest that OCUG-bearing mice exhibited cancer cachexia mediated by IL-6, and that of OCUG cell line might be useful as a human digestive cancer cachexia model.

Laparoscopic adrenalectomy: comparison with the conventional approach

Laparoscopic adrenalectomy (LA) was performed on 14 patients with adrenal tumors. Herein we describe the laparoscopic procedure and the patients' clinical course compared with those of patients who underwent the conventional posterior or transabdominal approach (PA, TA). The 14 patients included four men and 10 women aged 28 to 69 years. Clinical diagnoses in this series were primary aldosteronism in seven patients, Cushing's adenoma in four patients, and nonfunctioning tumor in three patients. Maximum diameters of the adrenal tumors ranged from 10 to 48 mm. In all patients, the adrenal tumors were removed successfully. The mean operating time was longer for LA- than for PA- or TA-treated patients (185 versus 99 and 143 min), whereas the mean blood loss was smaller for LA- or PA-treated (92 and 126 ml) than for TA-treated patients (407 ml). The patients' postoperative condition, as assessed in terms of the number of febrile days, leucocytosis, and elevation of C-reactive protein value, was significantly better with LA. In addition, the frequency of administration of analgesics was lower and the time required until the patient could walk were shorter after LA than after PA and TA. In conclusion, laparoscopic adrenalectomy appears to be a minimally invasive and safe therapeutic option that may become a standard procedure for adrenal surgery.

Expression of mucin-associated tumor antigens is altered by cell density

Mucin-associated sialylated Lewis antigens are implicated in tumor cell metastasis and are used in several tests for pancreatic cancer. Despite their clinical importance, little is known about the structures of the oligosaccharides of pancreatic cancer mucins or about the regulation of their synthesis or of the synthesis of their protein cores. In this study, we examined the effects of culture at high cell density on the expression of these antigens in the SW1990 human pancreatic cancer cell line. Mucins from cells that were 2.5 weeks post-confluent had increased expression of sialyl-Lewis(a) and Lewis(x) antigens but reduced expression of the DU-PAN-2 antigen (NeuAc alpha2,3Galbeta1,3GlcNAc-Gal-R) when compared to mucins from 1 day post-confluent cells. Sialyl-Lewis antigens differ from the DU-PAN-2 antigen by the presence of an additional fucose. Mucins from 2.5-week cells also had increased binding to lectins specific for fucose, such as AAL and UEAI, with no apparent change in the binding of lectins specific for sialic acids. Metabolically radiolabeled O-linked oligosaccharides with sialyl-Lewis(a) antigenic reactivity eluted from Bio-Gel P-10 in the region of sialylated and sulfated oligosaccharides. Oligosaccharides eluted from QAE-Sephadex (2 mM Tris base) in a pattern suggesting the presence of 1, 2 and 3 or more negative charges per oligosaccharide. Even after desialylation and desulfation, oligosaccharides eluted from Bio-Gel P-10 with apparent molecular sizes greater than glucose oligomers of 12 units. Culture of SW 1990 cells at high density also increased the steady-state levels of mRNA for mucins MUC1, 2, 4, 5 and 6. In summary, after prolonged culture at high cell density, SW1990 cells have qualitative changes in their oligosaccharides that may be due to up-regulation of fucosyltransferases.

[Malignancy of colorectal cancer analyzed by expression of cyclin D1]

We evaluated the clinical significance of cyclin D1 expression in colorectal adenocarcinoma. One hundred twenty-three specimens resected from patients with colorectal cancers were investigated by staining with a monoclonal antibody against cyclin D1. The possible correlations among cyclin D1 expression, clinicopathologic factors and prognosis were studied. There was no significant association between cyclin D1 expression and various clinicopathological factors. However, disease-free survival was significantly worse in the patients with cyclin D1 strongly positive tumors than in those with cyclin D1 negative tumors. Cyclin D1 overexpression may be useful as a predictor of disease recurrence in patients with colorectal adenocarcinoma.

[Immunohistochemical study of p21 expression in gastric carcinoma]

In this study, the expression of p21 protein was investigated immunohistochemically in 152 patients with gastric cancer. Expression of p21 was detected in 64 tumors (42.1%). There were significant differences among the expression of p21, histologic type, depth of invasion, lymph node metastasis, liver metastasis, and peritoneal metastasis. The deeper the tumor invaded, the more frequent p21 expression increased. Of the 152 patients, lymph node, liver and peritoneal metastasis were found in 86, 13 and 23 patients, respectively. p21 expression was more frequently lost in tumors from patients with metastasis. In relation to prognosis, patients with p21-positive tumors had a significantly better prognosis than those with p21-negative tumors. In conclusion, this study suggested that expression of p21 has a prognostic value in gastric cancer.

Continuous infusion of 5-fluorouracil and low dose cisplatin infusion for the treatment of advanced and recurrent gastric adenocarcinoma

BACKGROUND

Several chemotherapy studies have suggested that continuous infusion of 5-fluorouracil (5-FU) is more effective than bolus 5-FU. In addition, 5-FU and cis-Diamminedichloroplatinum-II (cisplatin) in combination have been shown to have synergistic cytotoxicity against several human neoplasms. In this study, the authors evaluated the efficacy and toxicity of continuous infusion of 5-FU and low dose cisplatin infusion (FP therapy) in the treatment of advanced and recurrent gastric adenocarcinoma. The relationship between the response to FP therapy and several factors was also examined.

METHODS

A total of 26 patients fulfilling standard eligibility criteria were enrolled in the trial. FP therapy consisted of 5-FU (350 mg/m2/day every day by continuous infusion) and cisplatin (7.5 mg/m2/day in 100 mL of normal saline infused over 1 hour on Days 1-5 every week) for 4 weeks.

RESULTS

A complete response was observed in 2 cases and a partial response in 11 cases, for an overall response rate of 50%. Patients with good performance status (PS) (0-1) and differentiated histologic type showed higher response rates (50.0% and 63.6%, respectively) than patients with poor PS (2 or 3) and undifferentiated histologic type (28.6% and 35.3%, respectively), although there were no significant differences. Patients with low serum levels of immunosuppressive acidic protein (IAP) showed a significantly higher response rate (71.4%) than those with high IAP levels (0%). Toxic effects included leukopenia, thrombocytopenia, nausea, and vomiting; these were not life-threatening and did not require treatment interruption.

CONCLUSIONS

FP therapy is a promising regimen for patients with advanced and recurrent gastric adenocarcinoma. Serum levels of IAP may predict chemosensitivity.

Overexpression of p53 associated with tumor angiogenesis, tumor cell proliferation, and prognosis in gastric carcinoma

Mutations in the p53 gene seem to be the most common genetic change in human malignancies. Recently, it was reported that p53 mutation was significantly associated with prognosis in various cancers. In this study, we investigated the correlation between p53 overexpression and prognosis of gastric carcinoma using immunohistochemical staining with an anti-p53 antibody. Although there was no significant association between p53 status and various clinicopathologic factors, prognosis of patients with p53-positive tumors was significantly worse than of those with p53-negative: tumors. Both microvessel count (MVC; the mean number of microvessels in the five areas of highest vascular density at 200x magnification) and PCNA labeling index (PCNA LI; percentage of positive cells per more than 500 tumor cells) were significantly higher in p53-positive tumors than in p53-negative tumors. In summary, it is suggested that p53 overexpression is closely associated with tumor angiogenesis, tumor cell proliferation and prognosis of gastric carcinoma.

Overexpression of cyclin D1 and p53 associated with disease recurrence in colorectal adenocarcinoma

Multiple genetic changes occur during the evolution of normal cells into cancer cells. It has been reported that both cyclin D1 and p53 genes play major roles in oncogenesis and/or cell cycle control in various cancers. In this study, we examined the overexpression of cyclin D1 and p53 by the immunohistochemical method and investigated the correlation between expression of these antigen and prognosis in patients with colorectal adenocarcinoma. Disease-free survival was significantly lower in the patients with cyclin D1-strongly positive tumors than in those with cyclin D1-negative tumors. Similarly, disease-free survival of the patients with p53-strongly positive tumors was significantly lower than that of those with p53-negative tumors. Moreover, multivariate analysis indicated that both cyclin D1 and p53 overexpression are independent prognostic factors in patients with colorectal adenocarcinoma. In conclusion, both cyclin D1 and p53 overexpression may be useful predictors of disease recurrence in patients with colorectal adenocarcinoma.

Intrasplenic combination immunotherapy with OK-432 and interleukin-2 on liver metastasis of colorectal carcinoma in a mouse model

We investigated the inhibitory effects of intrasplenic combination therapy with OK-432 and recombinant interleukin-2 (IL-2) on liver metastasis of colorectal carcinoma. Intrasplenic administration group significantly inhibited the development of liver metastasis compared with subcutaneous administration group (p<0.05). Combination therapy significantly inhibited the development of subclinical liver metastasis compared with that in the control group. Combination therapy decreased the percentage of cells expressing CD8a, which may be a part of effective factors of combination therapy, and improved overall survival rate. These findings suggested intrasplenic combination therapy with OK-432 and IL-2 might be effective in inhibiting liver metastasis of colorectal carcinoma.

A case of membranous glomerulonephritis associated with gastric cancer

We describe a patient with gastric cancer and membranous glomerulonephritis (MGN). The patient, a 61-year-old male, was admitted to our Hospital in May, 1996, because of proteinuria and hyperlipidemia persisting for a year. Laboratory examination filled the criteria of nephrotic syndrome and renal biopsy revealed MGN of stage II. Prednisolone therapy (40 mg/day p.o.) was started, followed by a gradual decrease in proteinuria from 4.5 g/day to 0.1 g/day. Endoscopic examination was performed because of stomach-ache revealed advanced gastric cancer of Borrmann 4. Desiring for a conservative therapy, he was discharged and moved to a hospice. In literature review, MGN is the most frequent lesion among various glomerular diseases associated with malignancy, such as the lung, stomach, and colon, particularly at an elderly ages, and sometimes antedates the detection of malignancy, as in the present case. In several cases with MGN, immune-complexes composed of tumor antigens, such as carcino-embryonic antigen, and antibodies have been reported to deposit in basement membrane of glomeruli, causing MGN. In the renal and gastric cancer tissues of the present case, the presence of three novel tumor-associated antigens, Span-1, Thomsen-Friedenreich antigen (T antigen) and F1 alpha antigen, was examined, using a immuno-peroxidase method. Although none of these three antigens were immuno-stained in the renal tissue, clinical course and literature review suggest that MGN in this patient seems to be associated with gastric cancer, which may have produced MGN-causing tumor antigens other than the three antigens. It should be emphasized that malignancy should be carefully and routinely examined in patients with MGN, particularly at elderly ages.

Identification and characterization of motility stimulating factor secreted from pancreatic cancer cells: role in tumor invasion and metastasis

Cell motility is an important factor in the process of invasion and metastasis of tumor. In this study, the relationship between cell motility and experimental metastatic potential was examined using two human pancreatic cancer cell lines, SW1990 and PANC-1. Serum-free conditioned medium from the highly metastatic cell line SW1990 was found to contain a factor that stimulated the migration of and induced a fibroblast-like morphological change in the weakly metastatic cell line PANC-1. Preincubation of PANC-1 cells with SW1990 conditioned medium (SW-C.M.) induced liver metastasis following splenic injection of PANC-1 cells in nude mice, although no liver metastasis was observed without pretreatment of SW-C.M. This factor, temporarily termed PDMF (pancreatic cancer-derived motility factor) is a heparin non-binding protein having a molecular weight of 40 kDa calculated by gel-filtration HPLC which acts not only chemotactically but also chemokinetically, and also acts mainly in a paracrine fashion. However, this factor had no effect on the proliferation of PANC-1 cells; it therefore appears to be a so-called motility factor. Only TGF-beta1 and IL-6 were recognized in the SW-C.M. among cytokines thought to stimulate cell motility. These cytokines stimulated the motility of PANC-1 cells, but differed from PDMF in the neutralizing test with antibody against these cytokines. Results of characterization and preliminary purification suggest that this factor may be a novel motility factor. The above findings suggest that this motility factor may play an important role in the invasion and metastasis of pancreatic cancer, and complete purification of it will be useful in elucidating the mechanism of progression of cancer and designing a strategy for inhibition of invasion and metastasis of pancreatic cancer.

Role of urokinase-type plasminogen activator and inhibitory effect of protease inhibitor in invasion and metastasis of pancreatic cancer

We investigated the association of urokinase-type plasminogen activator (u-PA) with tumor cell invasion and hepatic metastasis using human pancreatic cancer cell lines (SW1990, PANC-1, and RWP-1). We also examined the effect of the protease inhibitor, gabexate mesilate. SW1990 cells showed a higher u-PA activity (41.2 U/ml) in substrate assay and invasiveness (21.6% IV) than PANC-1 (14.3 U/ml, 10.3% IV) and RWP-1 (22.1, 13.5), which correlated with in vivo hepatic metastasis. Gabexate mesilate significantly reduced the u-PA activity, invasiveness, and hepatic metastasis of SW1990 cells. These findings suggest the possible application of protease inhibitors to prevent tumor invasion and metastasis.

Radioimmunodetection with 111In-labeled monoclonal antibody Nd2 in patients with pancreatic cancer

This report summarizes results from an initial clinical evaluation of radioimmunodetection (RAID) in patients with pancreatic cancer using murine monoclonal antibody Nd2, directed against mucins from pancreatic cancer. Nd2 (2 mg) was labeled with 111In (2 mCi) and injected into 19 patients suspected of having pancreatic cancer. Planar scintigrams were taken 3 days post-infusion. As for final diagnoses after surgery, 14 cases were pancreatic cancer, and one case each was chronic pancreatitis, neurilemmoma, islet cell carcinoma, cholangioma, and apparent absence of suspected recurrent lesion of pancreatic cancer. Of 14 patients with pancreatic cancer, RAID was positive in 10 cases (71.4%). Cases other than pancreatic cancer were all negative, so the specificity was 100%. These results demonstrate that RAID using 111In-Nd2 can be useful in differentiating exocrine pancreatic cancer from benign conditions and other types of carcinomas in the pancreatoduodenal regions.

18F-fluorodeoxyglucose positron emission tomography and the prognosis of patients with pancreatic adenocarcinoma

BACKGROUND

Fluorodeoxyglucose (FDG) detected by positron emission tomography (PET) can be used to measure the glycolytic activity of tumor cells. Though the prognosis of patients with pancreatic adenocarcinoma is usually poor, a subset of patients with good prognoses may be discovered by determining the degree of FDG integration into tumors.

METHODS

Fourteen patients with histologically proven pancreatic adenocarcinoma underwent 18F-FDG PET. The standardized uptake value (SUV) of 18F-FDG was calculated, and the patients were divided into high (> or = 3.0) and low (< 3.0) SUV groups.

RESULTS

The two groups were not significantly different in terms of age, tumor location and size, staging, and treatment. However, analysis by the Kaplan-Meier method revealed that the groups had different prognoses (log rank test, P < 0.05). The mean survival of patients with high SUV was 5 months, whereas that of patients with low SUV was 14 months. There were not strong correlations between the SUVs and tumor size (0.56), serum carbohydrate antigen 19-9 (0.39), or carcinoembryonic antigen (0.52).

CONCLUSIONS

SUV calculated with 18F-FDG can be utilized as a prognostic factor for patients with pancreatic adenocarcinoma.

18F-fluorodeoxyglucose positron emission tomography and the prognosis of patients with pancreatic adenocarcinoma

BACKGROUND

Fluorodeoxyglucose (FDG) detected by positron emission tomography (PET) can be used to measure the glycolytic activity of tumor cells. Though the prognosis of patients with pancreatic adenocarcinoma is usually poor, a subset of patients with good prognoses may be discovered by determining the degree of FDG integration into tumors.

METHODS

Fourteen patients with histologically proven pancreatic adenocarcinoma underwent 18F-FDG PET. The standardized uptake value (SUV) of 18F-FDG was calculated, and the patients were divided into high (> or = 3.0) and low (< 3.0) SUV groups.

RESULTS

The two groups were not significantly different in terms of age, tumor location and size, staging, and treatment. However, analysis by the Kaplan-Meier method revealed that the groups had different prognoses (log rank test, P < 0.05). The mean survival of patients with high SUV was 5 months, whereas that of patients with low SUV was 14 months. There were not strong correlations between the SUVs and tumor size (0.56), serum carbohydrate antigen 19-9 (0.39), or carcinoembryonic antigen (0.52).

CONCLUSIONS

SUV calculated with 18F-FDG can be utilized as a prognostic factor for patients with pancreatic adenocarcinoma.

Tranilast (N-(3,4-dimethoxycinnamoyl) anthranilic acid) down-regulates the growth of scirrhous gastric cancer

BACKGROUND

Fibroblasts have been reported to play an important role in the proliferation of scirrhous gastric cancer cells. It would be an effective cancer therapy to reduce the cancer-stimulating activity of fibroblasts. The aim of the present investigation was to define the efficacy of Tranilast (N-(3,4-dimethoxycinnamoyl) anthranilic acid), a drug used clinically for the treatment of excessive proliferation of fibroblasts, on the growth of scirrhous gastric carcinoma both in vitro and in vivo.

MATERIALS AND METHOD

The human scirrhous gastric cancer cell line, OCUM-2M, and the human gastric fibroblasts, NF-8, were used. OCUM-2M cells on the upper well and NF-8 cells in the lower well were co-incubated with Tranilast at the required concentrations in vitro. The in vivo effect of Tranilast was examined by measuring the size and the apoptotic index of coinoculated tumor by OCUM-2M cells and NF-8 cells.

RESULTS

The proliferation of OCUM-2M cells was significantly stimulated by co-culture with NF-8 cells. Tranilast significantly suppressed the proliferation of NF-8 cells and subsequently decreased the growth of OCUM-2M cells in vitro. Furthermore, Tranilast depressed gastric carcinoma growth and induced cancer cell apoptosis through its effect in blocking the growth-interactions between fibroblasts and scimbous gastric cancer cells in vivo.

CONCLUSION

Tranilast is a useful drug to reduce the proliferation of scirrhous gastric carcinoma.

Vascular endothelial growth factor expression correlates with hematogenous metastasis and prognosis in colorectal carcinoma

We investigated the expression of vascular endothelial growth factor (VEGF) in 175 colorectal carcinomas by immunohistochemistry. VEGF expression was correlated with advanced TNM stage (III, IV), advanced T stage (T3, T4), vessel involvement, lymph node metastasis, and liver metastasis. With regard to the prognosis, both overall and relapse-free survival was significantly poorer, and furthermore, the hematogenous recurrences were significantly more commonly found in the patients with VEGF-positive tumors. VEGF expresion in colorectal carcinomas may have a substantial value in predicting those patients at high risk for hematogenous recurrence after surgery.

Transforming growth factor-beta and hepatocyte growth factor produced by gastric fibroblasts stimulate the invasiveness of scirrhous gastric cancer cells

Scirrhous gastric carcinoma is characterized by cancer cells that infiltrate rapidly in the stroma with extensive growth of fibroblasts. In the present study, we examined the effect of gastric fibroblasts on the invasiveness of a scirrhous gastric cancer cell line, OCUM-2D, using an invasion assay. Gastric fibroblast-derived conditioned medium (CM) significantly stimulated the invasiveness of OCUM-2D cells, as did transforming growth factor-beta (TGF-beta) and hepatocyte growth factor (HGF). The stimulating activity of gastric fibroblast-derived CM was inhibited significantly by anti-TGF-beta neutralizing antibody or anti-HGF neutralizing antibody. TGF-beta and HGF were detected in the gastric fibroblast-derived CM, and TGF-beta receptor and C-met (HGF receptor) were expressed on OCUM-2D cells. Thus, TGF-beta and HGF produced by gastric fibroblasts appear to affect the invasiveness of scirrhous gastric cancer cells. TGF-beta was also detected in the conditioned medium derived from OCUM-2D cells, though HGF was not. TGF-beta appears to affect the invasiveness of OCUM-2D cells in both paracrine and autocrine fashions.

Increased sialyl Lewis A expression and fucosyltransferase activity with acquisition of a high metastatic capacity in a colon cancer cell line

A human colon cancer cell line, OCUC-LM1(LM), was established from a liver metastasis in our laboratory. Intrasplenic injection of LM into nude mice was repeated three and five times, and the daughter cell lines were designated as LM-H3 and LM-H5 respectively. The level of sialyl Lewis A (SLA) in the supernatant of LM-H3 and LM-H5 was 3 and 4.5 times higher than that of LM respectively. Flow cytometric analysis of SLA expression showed that the peak channel for LM was 113; for LM-H3, 126; and for LM-H5, 146. The mean fluorescence intensity of LM was 102.3 +/- 43.5; for LM-H3, 126.2 +/- 28.4; and for LM-H5, 144.8 +/- 23.4. In endothelial cell adhesion assays, the percentages of adherent LM-H3 and LM-H5 cells were significantly higher than for LM. The activity of alpha1-->4 fucosyltransferase was higher in LM-H3 and LM-H5 than in LM, but there was no difference in alpha2-->3 sialyltransferase activities for type 1 chain among the cell lines. Our results suggest that SLA expression is associated with acquisition of a high capacity for liver metastasis of colon cancer; increased SLA expression is due mainly to increased fucosyltransferase activity.

Establishment of a cisplatin-resistant gastric carcinoma cell line OCUM-2M/DDP

A cis-diamminedichloroplatinum (CDDP)-resistant scirrhous gastric cancer cell line, OCUM-2M/DDP, was established by chronic exposure of cells of the parent scirrhous gastric cancer cell line, OCUM-2M, to CDDP at progressively increasing concentrations. The OCUM-2M/DDP cell line had an 11.3-fold higher level of resistance relative to its parent cell line as determined by a succinate dehydrogenase inhibition test. The biological and biochemical characteristics of the resistant and parent cell line were compared. There were differences in the modal chromosome number and DNA index, suggesting that some alterations of the DNA in the CDDP-resistant cells had occurred. Neither the parent nor resistant cell line expressed mdr-1 mRNA. After exposure to CDDP for 4 h, the intracellular platinum content of OCUM-2M cells was significantly higher than that of OCUM-2M/DDP cells (51.9 +/- 1.8 vs 16.4 plus 1.0 ng/mg protein, mean +/- SD, respectively). The GSH levels in OCUM-2M cells and OCUM-2M/DDP cells were 3.5 +/- 1.0 micrograms/mg protein and 16.8 +/- 1.2 micrograms/mg protein, respectively. These levels were also significantly different. These findings suggest that the possible mechanisms of acquired resistance to CDDP in OCUM-2M/DDP cells may be a decrease in intracellular CDDP accumulation and detoxication by GSH. This OCUM-2M/DDP cell line could be used in further investigations of the mechanism of CDDP resistance in gastric cancer.

Loss of p21WAF1/CIP1 expression correlates with disease progression in gastric carcinoma

Previous studies have shown that tumour-suppressor genes play an important role in the progression of solid tumours. Recently, the p21WAF1/CIP1 tumour-suppressor protein has been reported to work as a critical downstream effector of p53 and a potent inhibitor of cyclin-dependent kinases. Thus, the p21WAF1/CIP1 gene is thought to play a central role in tumour suppression. In this study we investigated p21 protein expression in gastric carcinomas. A total of 172 primary gastric carcinoma specimens were immunohistochemically stained for p21 protein expression. Correlations between p21 expression and clinicopathological features were examined. Loss of p21 expression was observed in 104 of 172 tumour tissues (60.4%), and the frequency of p21 loss increased as the stage progressed. Expression of p21 in the primary tumour was frequently lost in patients with either lymph node, liver or peritoneal metastases as compared with patients without metastases. In patients with p21-negative tumours, the risk of recurrence following curative surgery was significantly higher, and the prognosis was significantly poorer than in patients with p21-positive tumours. Loss of p21 expression in primary gastric carcinoma correlates with disease progression. The status of p21 gene expression may have prognostic value in this disease.

CD44H plays an important role in peritoneal dissemination of scirrhous gastric cancer cells

The role of the adhesion molecule CD44H in the peritoneal adhesion and invasion of cancer cells was assessed using cell lines with low and high peritoneal seeding ability, OCUM-2M (2M) and OCUM-2MD3 (2MD3), respectively. The in vitro binding ability to peritoneal components (mesothelial cells, fibronectin and type I collagen) and invasive ability of 2MD3 cells were higher than those of 2M cells. The expression level of CD44H on 2MD3 cells was higher than that on 2M cells as determined by western blot analysis and flow cytometry. The adhesiveness of 2MD3 cells to hyaluronic acid, which is expressed on the surfaces of mesothelial cells, was greater than that of 2M cells. The binding ability of 2MD3 cells to mesothelial cells was inhibited in the presence of anti-CD44H monoclonal antibody, but that of 2M cells was not. These results suggested that the 2MD3 cell binding to mesothelial cells is regulated by the CD44-hyaluronic acid dependent system. The in vitro binding to submesothelial components and the invasiveness of 2MD3 cells were also inhibited in the presence of anti-CD44H antiody. The in vivo inoculation of 2MD3 cells treated with an anti-CD44H antibody resulted in a significiant prolongation of survival time as compared with control mice that were inoculated with 2MD3 cells alone. In conclusion, CD44H was associated with attachment not only to hyaluronic acid on mesothelial cells, but also to peritoneal stromal components. Thus, CD44H may play an important role in cancer cell binding and invasion in the peritoneal dissemination of scirrhous gastric cancer cells.