We report the cloning and characterization of a cancer-associated cell membrane glycoprotein recognized by mAb NCC-3G10. The antibody showed strong reactivity to a wide variety of cancer cells, but only to a limited number of normal cells including lymphocytes, endothelial cells, and basal cells of stratified squamous epithelium. The cDNA for the antigen encodes 178 aa, which includes a putative signal sequence, a potential O-glycosylated extracellular domain, a single transmembrane domain, and a short cytoplasmic tail. Transfection of the cDNA into PLC͞PRF͞5 liver cancer cells resulted in reduced cell-cell adhesiveness, based on both morphology and results of Ca 2؉ -dependent cell aggregation assay. In transfected cells, E-cadherin was markedly decreased at the protein level in inverse proportion to the expression level of the antigen recognized by NCC-3G10, but not at the mRNA level. Aggregation of the antigen by NCC-3G10-coated beads triggered accumulation of actin, suggesting some interplay between this antigen and Ecadherin through actin. When metastatic ability was examined in severe combined immunodeficient mice by injecting PLC͞PRF͞5 cells into the spleen, the transfectants formed a markedly higher number of metastatic nodules in comparison with controls. We have named this cell membrane glycoprotein, which downregulates E-cadherin and promotes metastasis, dysadherin. T he cadherins are members of a large family of transmembrane glycoproteins that mediate calcium-dependent, homophilic cell-cell adhesion and play an important role in the maintenance of normal tissue architecture (1). Cadherins are connected indirectly to the actin cytoskeleton by means of a group of proteins known as the catenins. The transmembrane cadherin is associated with either ␤-catenin or plakoglobin, which in turn associates with ␣-catenin, and then ␣-catenin mediates the interaction between the cadherin-catenin complex and the actin cytoskeleton (2-4). Numerous studies have demonstrated the importance of the E-cadherin͞catenin complex in normal development, maintenance, and repair of tissue and tumor development. Early studies showed that inhibition of E-cadherin activity with function-perturbing antibodies altered the morphology of Madin-Darby canine kidney cells and conferred on them the ability to invade collagen gels and embryonic chicken heart tissue (5, 6). Invasive fibroblast-like carcinoma cells could be converted to a noninvasive phenotype by transfection with a cDNA encoding E-cadherin (7). Several studies have reported a correlation between decreased function of the E-cadherin͞catenin complex and the initiation and progression of human tumors. Several mechanisms for the irreversible and reversible inactivation of the E-cadherin͞catenin complex in human tumors have been reported (8). Mutations have been reported in the genes for E-cadherin and ␣-and ␤-catenins (9-12). Transcriptional inactivation of E-cadherin expression was shown to occur by deoxycytidylate-phosphate-deoxyguanylate methylation around the promoter regio...

We demonstrate a high yield production scheme to fabricate sub-10 nm co-planar metal-insulator-metal junctions without using electron beam lithography. The fabricating procedure contains two photolithographys followed by shadow evaporation. Ultrasmall gaps were formed in the crossing region of the two metal layers during the evaporation of the second layer. The sizes of the gaps were estimated using scanning electron microscopy images. Poly (3-hexylthiophene-2,5-diyl) layers were deposited on the junctions using a special ink-jet technique. The results of the conductivity measurement of the molecular layer indicate that these junctions can be used in the study of molecular sensors.

The surface structures of polyamic acid and polyimide films made by vapor deposition polymerization (VDP) technique were investigated using infrared−visible sum-frequency generation (SFG). From the SFG spectra of VDP-made polyamic acid films, the polymer chains have a broad orientational distribution, and residual monomers are observed even for a sample that was kept in air for more than 3 months. The amidization reaction of surface residual monomers is quite slow at room temperature, and the reaction proceeds preferentially in the bulk film. In the early stage of curing, surface species become parallel to the surface plane. After the surface reorientation, the imidization reaction proceeds.