Epidermal growth factor (EGF) induced the disruption and scattering of colonies of TMK-1, a cell line derived from a human gastric carcinoma. A stimulatory action of EGF on cell migration was also observed as determined by a wound assay. However, these actions of EGF were inhibited if the cells were pretreated with dexamethasone, a synthetic glucocorticoid. Dexamethasone increased cell adhesion to collagen type IV and laminin, but not to poly-L-lysine and fibronectin. In contrast, EGF did not affect cell adhesion to these extracellular matrices whether dexamethasone was present or not. Dexamethasone enhanced the protein levels of both alpha 1 and beta 1 integrin subunits, and that of the alpha 1 beta 1 heterodimer. Further, flow cytometric analysis revealed that dexamethasone increased the expression of beta 1 and alpha 1 integrin subunits at the cell surface, whereas EGF increased expression of beta 1 and alpha 2 subunits at the cell surface. Antibodies against alpha 1 and beta 1 integrin subunits inhibited the increased cell adhesion seen in the presence of dexamethasone. An immunofluorescence study indicated that dexamethasone increased the formation of focal adhesions along the entire edges of cell colonies. In contrast, EGF led to the formation of focal adhesions preferentially at the cell front, and this EGF-induced preferential formation was not observed if the cells were pretreated with dexamethasone. These results Suggest that glucocorticoid increased cell adhesion to the extracellular matrix via alpha 1 beta 1 integrin, and thereby antagonized EGF-induced cell migration. (C) 1998 Wiley-Liss, Inc.

Hepatocyte growth factor (HGF) stimulated cell migration of human gastric carcinoma cell lines MKN1, MKN7, and MKN28. Epidermal growth factor (EGF) also stimulated the cell migration of these three cell lines. In MKN7 cells, HGF-stimulated cell migration was rather reduced in the presence of EGF, whereas such an observation was not made with MKN1 and MKN28 cells. Therefore, we compared the effect of EGF on HGF-stimulated HGF receptor phosphorylation in these cell lines. HGF induced a rapid tyrosine phosphorylation of the HGF receptor in all these cell lines. In MKN7 cells, the increased phosphorylation was further enhanced by EGF, although EGF alone did not affect tyrosine phosphorylation of the HGF receptor. In MKN1 and MKN28 cells, EGF did not influence tyrosine phosphorylation of the HGF receptor, whether HGF was present or not. The data presented here suggest that EGF negatively modulates the cellular response to HGF by increasing tyrosine phosphorylation of the HGF receptor in certain types of epithelial cells, e.g., MKN7 cells.

p120 was originally identified as a substrate of pp60src and several receptor tyrosine kinases, but its function is not known. Recent studies revealed that this protein shows homology to a group of proteins, beta-catenin/Armadillo and plakoglobin (gamma-catenin), which are associated with the cell adhesion molecules cadherins. In this study, we examined whether p120 is associated with E-cadherin using the human carcinoma cell line HT29, as well as other cell lines, which express both of these proteins. When proteins that copurified with E-cadherin were analyzed, not only alpha-catenin, beta-catenin, and plakoglobin but also p120 were detected. Conversely, immunoprecipitates of p120 contained E-cadherin and all the catenins, although a large subpopulation of p120 was not associated with E-cadherin. Analysis of these immunoprecipitates suggests that 20% or less of the extractable E-cadherin is associated with p120. When p120 immunoprecipitation was performed with cell lysates depleted of E-cadherin, beta-catenin was no longer coprecipitated, and the amount of plakoglobin copurified was greatly reduced. This finding suggests that there are various forms of p120 complexes, including p120/E-cadherin/beta-catenin and p120/E-cadherin/plakoglobin complexes; this association profile contrasts with the mutually exclusive association of beta-catenin and plakoglobin with cadherins. When the COOH-terminal catenin binding site was truncated from E-cadherin, not only beta-catenin but also p120 did not coprecipitate with this mutated E-cadherin. Immunocytological studies showed that p120 colocalized with E-cadherin at cell-cell contact sites, even after non-ionic detergent extraction. Treatment of cells with hepatocyte growth factor/scatter factor altered the level of tyrosine phosphorylation of p120 as well as of beta-catenin and plakoglobin. These results suggest that p120 associates with E-cadherin at its COOH-terminal region, but the mechanism for this association differs from that for the association of beta-catenin and plakoglobin with E-cadherin, and thus, that p120, whose function could be modulated by growth factors, may play a unique role in regulation of the cadherin-catenin adhesion system.

The effect of hepatocyte growth factor/scatter factor (HGF/SF) and epidermal growth factor (EGF) on cadherin-mediated adhesion of human carcinoma cells was studied. HGF/SF induced scattering of colonic adenocarcinoma HT29 and gastric adenocarcinomas MKN7 and MKN74 cells. Likewise, EGF induced scattering of HT29 and MKN7 cells. These cells expressed E-cadherin, which was concentrated at cell-cell contact sites. When the scattering of these cells was induced by HGF/SF or EGF, the E-cadherin concentration at cell-cell boundaries tended to decrease. Immunoblotting analyses, however, demonstrated that these growth factor treatments did not alter the expression of E-cadherin and E-cadherin-associated proteins, alpha- and beta-catenin and plakoglobin. Beta-catenin, plakoglobin and an unidentified 115-kDa molecule associated with E-cadherin were found to be phosphorylated at tyrosine residues, and these phosphorylations were enhanced by the growth factor treatments. These results suggest that HGF/SF and EGF may modulate the function of the cadherin-catenin system via tyrosine phosphorylation of cadherin-associated proteins.

The role of phospholipase A2 (PLA2) in the cytotoxic action of tumor necrosis factor (TNF) was examined. Recently, we described the characterization of TNF-resistant sublines isolated from TNF-sensitive cell line L929 (Hayakawa, M., Oku, N., Takagi, T., Hori, T., Shibamoto, S., Yamanaka, Y., Takeuchi, K., Tsujimoto, M., and Ito, F. (1991) Cell Struct. Funct. 16, 333-340). The most remarkable features of these TNF-resistant sublines were the defects in TNF-stimulated arachidonate metabolism. In this study, we characterized the PLA2 activities of these sublines and found a significant decrease in the activity in one of the TNF-resistant sublines, C12 cells. The enzymological features, such as Ca2+ requirement and substrate specificity, suggested that the high molecular weight arachidonoyl-selective cytosolic PLA2 (cPLA2) was involved in the TNF action. Northern hybridization analysis demonstrated the reduced expression of high molecular weight cPLA2 in C12 cells. Furthermore, expression of a cloned cPLA2 cDNA in C12 cells increased the sensitivity of cells to the TNF cytotoxicity. These results indicate the crucial role of the high molecular weight cPLA2 in the TNF-induced cytolysis.

Hepatocyte growth factor (HGF), a protein with pleiotropic biological activity affecting cell growth and motility, was found to markedly activate prostaglandin production in human gastric carcinoma TMK-1 cells. HPLC analysis revealed that HGF stimulated the production of prostaglandin E2 (PGE2), which is the major prostaglandin produced in these cells. HGF maximally stimulated PGE2 production at a concentration of 10 ng/ml, and it was a more potent stimulator of PGE2 production than epidermal growth factor (EGF), which is known to stimulate prostaglandin production in various cell lines. The simultaneous addition of HGF and EGF caused no further stimulation of the PGE2 production observed in HGF-treated cells. We showed also that HGF increased the arachidonate release from TMK-1 cells, which release was completely suppressed by the addition of phospholipase A2 (PLA2) inhibitors. Further studies in vitro showed that HGF enhanced cellular activities of cytosolic PLA2 and cyclooxygenase 1.5-fold each. These results indicate that HGF stimulates prostaglandin production through increases in both cytosolic PLA2 and cyclooxygenase activities.

Hepatocyte growth factor (HGF) induced scattering and cell migration of human gastric adenocarcinoma MKN-74. HGF also significantly promoted the growth of MKN-74 cells in a dose-dependent manner, although HGF is reported to be antiproliferative for the growth of tumor cell lines. This result indicates that HGF stimulates cell proliferation of not only normal epithelial cells but also certain carcinoma cells. Furthermore, transforming growth factor-beta (TGF-beta), which is recognized to inhibit the growth of most epithelial cells, additively enhanced both the cell proliferation and migration induced by HGF. These additive effects of HGF and TGF-beta may be responsible for the tumor invasiveness and uncontrolled growth of certain types of carcinoma.

This is a report of our experience with 22 cases of large unruptured omphaloceles treated by amnion inversion during the period 1973 through 1990. The method is characterized by three stages: (1) a silastic sheet is sutured directly to the skin around the amniotic membrane, under local anaesthesia, without dissection between the skin and the amnion; (2) the reduction of herniated viscera into the abdominal cavity is achieved by squeezing the sheeting using a specially modified stapler; and (3) the amniotic membrane is preserved intact, and inverted into the abdominal cavity at the time of abdominal wall closure. Of the 22 infants, 19 survived with satisfactory results. Two patients died of multiple associated anomalies, and the remaining patient died of sepsis arising at the time of the final abdominal closure. This procedure has proved to be effective and safe for high-risk patients with congenital heart diseases, anal atresia, tracheoesophageal fistula, or bronchial stenosis and prematurity. The practical aspects of the procedure, as well as its advantages and pitfalls, are illustrated.

Tumor necrosis factor (TNF) is known to be a mitogen for human diploid FS-4 fibroblasts. We have shown in an earlier study (Hori et al. (1989)J.Cell.Physiol.141,275–280) that indomethacin further enhances the cell proliferation stimulated by TNF. Since indomethacin inhibits the activity of cyclooxygenase, the role of prostaglandins in TNF-stimulated cell growth was examined. Cell growth stimulated by TNF and indomethacin was inhibited by exogenously added prostaglandins (PGE2, PGF2α, and PGD2), among which PGE2 caused the greatest inhibition of cell growth. Treatment of FS-4 cells with 10 ng/ml TNF resulted in the release of prostaglandins (PGE2, 6-keto-PGF1α, PGA2, PGD2, and PGF2α) 2 to 4 fold over that of untreated cells. The amount of all these prostaglandins increased in a time-dependent manner over 6 h after treatment. In both TNF-treated and control cells, PGE2 was released as the predominant prostaglandin. Furthermore, when PGE2 production and DNA synthesis were determined in FS-4 cells treated with increasing doses of indomethacin, these two cellular responses were inversely affected by indomethacin. These data show that prostaglandins induced by TNF antagonize growth stimulatory action of TNF.

A 4-month-old infant with a huge unresectable hepatoblastoma was treated by continuous infusion therapy with 5-fluorouracil, vincristine, Adriamycin, and cisplatin, through the hepatic artery. Following 18 months of chemotherapy, the tumor disappeared completely and the initially sky-high serum α-fetoprotein levels returned to normal. At the time of this report, the patient continues to do well without tumor recurrence 6 years following discontinuation of the combination chemotherapy.

To elucidate the cytotoxic mechanism of tumor necrosis factor (TNF), we isolated TNF-resistant sublines of L929 cells. As compared with L929 cells, TNF-resistant cells retained similar number and affinity of TNF-binding sites, and showed a similar growth rate. TNF stimulated arachidonate release from L929 cells, while no stimulation was observed at all in TNF-resistant cells tested. The cytotoxic action of TNF on L929 cells was inhibited by indomethacin, suggesting that prostaglandin may be involved in the action. Therefore, TNF-stimulated prostaglandin production was examined in L929 and TNF-resistant sublines. The amount of PGE2 produced by L929 cells was increased more than 5-fold after the addition of TNF, whereas the amount of PGE2 did not change in the resistant sublines following addition of the factor. TNF-stimulated arachidonate release and PGE2 production were reversed by islet-activating protein (IAP)-treatment of L929 cells. These results suggest that arachidonate release and subsequent prostaglandin production are important for the cytotoxic action of TNF and that these processes are mediated by GTP-binding protein (G protein) that is coupled to the TNF-receptor.

Human placental membranes exhibited high-affinity receptors for tumor necrosis factor (TNF) (Kd = 5.6 × 10−10 M) with a density of 1.2-1.7 × 1010 sites/mg protein. The receptors were solubilized from these membranes with 1% Nonidet P-40, and the solubilized receptor was adsorbed to Con A-Sepharose and wheat germ agglutinin agarose columns, indicating that the TNF receptor derived from human placenta contains carbohydrate chains recognized by these lectins. TNF binding activity was eluted from a column of Sephacryl S-300 as a single peak of Mr 300 kDa. The solubilized receptor was further purified by TNF-Sepharose prepared by coupling of TNF to tresyl-activated Sepharose 4B. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the purified sample resolved five major bands of Mr 90, 78, 41, 35, and 11 kDa, suggesting that these polypeptides constitute a multimeric complex with a molecular mass of 300 kDa, as observed in gel filtration study. Furthermore, the TNF-Sepharose-bound fraction demonstrated GTPγS binding and GTPase activity. Immunoblot analysis showed that the 41- and 35-kDa polypeptides were recognized by antisera against α subunits and β subunit of GTP-binding proteins, respectively. These results suggest that the native TNF receptor couples to a guanine nucleotide-binding protein to form a large complex structure in human placental membranes.

The effect of epidermal growth factor on growth of human fibroblasts was investigated in serum-free medium supplemented with various fatty acids. When linoleic acid, arachidonic acid, or eicosapentaenoic acid was added, each inhibited epidermal growth factor-induced cell growth and showed cytotoxicity at high concentrations (greater than 10 microM). This cytotoxic effect was not observed in the presence of indomethacin, suggesting that prostaglandin production is important in mediation of the growth inhibition. Prostaglandin E2 was increased more than ten thousand times by epidermal growth factor in combination with arachidonic acid.

The effects of three local anesthetics, lidocaine, dibucaine, and tetracaine, on Na+/H+ antiporter activity were examined in brush border membrane-reconstituted vesicles. Lidocaine at 10 μM inhibited H+ efflux in the presence of an inward Na+ gradient, suggesting that this anesthetic specifically inhibits the Na+/H+ antiporter. On the other hand, dibucaine and tetracaine decreased H+ efflux even in the absence of a Na+ gradient.

A 30-month-old boy was investigated because of a huge abdominal mass in the right upper abdomen. A computed tomography scan and celiac angiography showed that the tumor involved bilateral lobes of the liver. At first, for this disseminated and “unresectable” tumor we did liver biopsy and hepatic arterial catheterization. Through this catheter we started chemotherapy using THP-Adriamycin and cis-platinum. After three courses of chemotherapy, a second-look operation was performed and trisegmentectomy was done to remove the main tumor and metastases, including the left lobe and the right anterior segment. The trisegmentectomy was performed with success, and the boy's serum α-fetoprotein (AFP) remains normal 37 months after the start of treatment, indicating a probable permanent cure. Such cases have rarely been reported in the literature. Our experience in treating this patient would seem to encourage aggressive management of advanced hepatoblastoma in other patients.

Recombinant tumor necrosis factor (TNF), epidermal growth factor (EGF), and transforming growth factor β (TGF‐β) stimulated growth of confluent human diploid fibroblasts (FS‐4 cells) in the presence of fetal calf serum. TGF‐β synergistically enhanced both the TNF‐ and EGF‐stimulated cell growth, whereas synergism between the mitogenic action of EGF and that of TNF was not observed. When indomethacin or acetylsalicylic acid, an inhibitor of prostaglandin production, was added to FS‐4 cells, cell growth stimulated by EGF or TNF was increased, suggesting that prostaglandins induced by these mitogens antagonize their growth stimulatory actions. In contrast, neither indomethacin nor acetylsalicylic acid had a significant effect on the TGF‐β‐induced growth of FS‐4 cells. Mitogenic responses of indomethacin‐treated cells to EGF, TNF, and TGF‐β were similarly suppressed by the addition of exogenous prostaglandin D2 (PGD2). Other prostaglandins such as PGE2 and PGF2α produced less inhibition of the cell growth.

Recombinant human tumor necrosis factor (TNF) stimulated the growth of confluent human ftbroblasts (FS-4) in serum-free culture medium. However, TNF had a cytotoxic effect upon the growth of FS-4 cells in combination with arachidonic acid. When arachidonic acid was added to culture medium in the absence of TNF, however, it had no effect on the cell growth. Arachidonic acid inhibited the TNF-induced cell growth in a dosedependent manner: it reversed the TNF-stimulated growth to the control level at a concentration of 10 μM and was cytotoxic to TNF-treated FS-4 cells at higher concentrations. This cytotoxicity of TNF was not observed in FS-4 cells treated with palmitic acid. Indomethacin, a cyclooxygenase inhibitor, decreased the cytotoxic effect that TNF exerted in the presence of arachidonic acid. These results suggest that TNF becomes cytotoxic to FS-4 cells when arachidonic acid present in the culture medium is converted to prostaglandins.

As an assay system for mass screening of infants with neuroblastoma, a new method of determining urinary vanillylmandelic acid (VMA) and hemovanillic acid (HVA) levels--an enzyme immunoassay (EIA) method--was developed. By using two different monoclonal antibodies, one against VMA and the other against HVA, this system can assay 400 urine samples for both catecholamine metabolites in five hours. By measuring both VMA and HVA levels in 275 urine samples (62 from patients with neuroblastoma, 13 from patients with control tumors, 200 from healthy infants as controls) by the EIA method, as well as by high performance liquid chromatography (HPLC), we examined whether the EIA system is as accurate as the HPLC. There were significant correlations between values obtained by the two systems, both for VMA and for HVA, suggesting that the EIA method would be a more reliable and convenient system for mass screening of infantile neuroblastoma as compared with conventional qualitative tests with inevitable high false-positive rate.