No abstract

The prognostic value of epidermal growth factor (EGF) receptor level was studied in 32 patients with esophageal squamous cell carcinoma. The EGF receptor levels of tumors were measured by iodine 125 (Iz5I)-EGF binding assay, and the patients subsequently were divided into two groups: a group with high EGF binding capacities (22.5% of input), and a group with low EGF binding capacities (<2.5% of input). The cumulative survival rates for the two groups were calculated by the Kaplan-Meier method. The generalized Wilcoxon test indicated that the survival rate of the high EGF binding group was significantly lower than that of the low EGF binding group (P < 0.05). In tumors from two patients with the highest EGF receptor levels, EGF receptor gene amplification was observed. These patients developed mediastinal lymph node metastasis and died 4 and 11 months after surgery, respectively. These results suggest that elevated EGF receptor level is a significant prognostic indicator for esophageal squamous cell carcinoma.

Abstract. P-cadherin is a subclass of Ca2+-dependent cell-cell adhesion molecules present in mouse placenta, where its localization suggests a function of connecting the embryo to the uterus (Nose, A., and M. Takeichi. 1986. J. Cell Biol. 103:2649-2658. We recently identified a human cadherin detected by an mAb capable of disrupting cell-cell adhesion of A-431 cells, and found that it was closely related immunochemically to mouse P-cadherin. Curiously, this cadherin was undetectable in human placenta by immunohistochemical examination (Shimoyama, Y., S. Hirohashi, S. Hirano, M. Noguchi, Y. Shimosato, M. Takeichi, and O. Abe. 1989. Cancer Res. 49:2128-2133. We here report the cloning and sequencing of a cDNA clone encoding the human homologue of mouse P-cadherin. The deduced amino acid sequence of the human P-cadherin consists of 829 amino acids and shows striking homology with mouse P-cadherin. On Northern blot analysis, human P-cadherin was scarcely expressed in human placenta in contrast to mouse P-cadherin, which was abundantly expressed in mouse placenta throughout pregnancy, and it was shown that E-cadherin, but not P-cadherin, was the major cadherin molecule in human placenta. Moreover, NIH3T3 cells transfected with human P-cadherin cDNA expressed the functional cadherin molecule, which was identical to the cadherin we had previously identified using the mAb, showing that this molecule really does mediate cell-cell adhesion and that the cadherin we detected immunochemically is undoubtedly human P-cadherin. The results obtained in this study support the idea that P-cadherin plays little role, if any, in Ca2+-dependent cell-cell binding in human placental tissue at least after several weeks of pregnancy. CADHERINS are integral membrane glycoproteins responsible for Ca2+-dependent cell-cell adhesion. At present it is known that they constitute a gene family consisting of at least three subclasses, E-, N-, and P-cadherin. In developing embryos, each subclass shows a unique spatiotemporal pattern of expression that coincides with the movement and rearrangement of cell collectives, suggesting that cadherins play a key role in morphogenetic events (for review, see reference 22). Recent studies using cells transfected with cadherin cDNAs have demonstrated experimentally that cadherin molecules are directly involved in ceU-ceU binding (2, 15), and that they can control cell sorting in vitro (18). Their cell-cell binding function is mediated not by a ligand-receptor complex but occurs in a homophilic manner (2) in cooperation with certain cytoskeletal components (15).We recently reported the establishment of two mAbs recognizing two human cadherins, which are distinct from each other in terms of immunological specificity, molecular weight, and tissue distribution (20). One of them showed a broad spectrum of expression in epithelial tissues with few exceptions, and was subsequently identified as human E-cadherin, which is possibly identical to cell-CAM 120/80 (1). In contrast, the tissue distribution of the other ca...

A phase I clinical and pharmacokinetic study of recombinant human tumor necrosis factor (rH-TNF) was conducted in a single dose schedule in 33 patients with advanced cancer. rH-TNF was given by i.v. infusion over 30 min with a starting dose of 1 x 10(5) units/m2. The dose was escalated up to 16 x 10(5) units/m2 according to the modified Fibonacci scheme. Toxic effects were similar but not identical to those reported with interferons and interleukin-2, and included fever, rigors, nausea and vomiting and anorexia in a non-dose-dependent manner, and hypotension, leukocytosis, thrombocytopenia and transient elevation of transaminases (SGOT and SGPT) in an approximately dose-dependent manner. DIC syndrome was observed in one patient who had received 16 x 10(5) units/m2. The dose-limiting toxicities were hypotension, thrombocytopenia and hepatotoxicity, and the maximum tolerated dose in a single i.v. infusion of rH-TNF appeared to be 12 x 10(5) units/m2 when thrombocytopenia and elevation of SGOT and SGPT were taken as the dose-limiting toxicities. However, if hypotension was included, the maximum safely tolerated dose appeared to be 5 x 10(5) units/m2.

EGF receptor levels were investigated in esophageal squamous-cell carcinoma tissues from 31 patients. Twenty-two (71%) of these cancer tissues exhibited significantly higher 125I-EGF binding activity than normal mucosa in the adjacent non-cancerous tissues. These EGF receptor levels were then compared on the basis of pathological findings including lymph-node metastasis, depth of invasion, differentiation type, vascular invasion, infiltration and location of the lesion. Unlike previous reports on breast and bladder cancers, our study showed no obvious correlation between these pathological characteristics and the EGF receptor levels in esophageal carcinomas. Immunohistochemical staining with the anti-EGF receptor monoclonal antibody detected EGF receptors in squamous cells of the cancer tissues as well as in the basal cells of nearby normal epithelium. Since the basal cells have proliferative potential in the esophagus, the increase in EGF receptor levels in these cells may possibly be associated with the development of human esophageal squamous-cell cancer.