Seong-Hun Park

TMPRSS4 promotes invasion, migration and metastasis of human tumor cells by facilitating an epithelial–mesenchymal transition

TMPRSS4 is a novel type II transmembrane serine protease found at the cell surface that is highly expressed in pancreatic, colon and gastric cancer tissues. However, the biological functions of TMPRSS4 in cancer are unknown. Here we show, using reverse transcription–PCR, that TMPRSS4 is highly elevated in lung cancer tissues compared with normal tissues and is also broadly expressed in a variety of human cancer cell lines. Knockdown of TMPRSS4 by small interfering RNA treatment in lung and colon cancer cell lines was associated with reduction of cell invasion and cell-matrix adhesion as well as modulation of cell proliferation. Conversely, the invasiveness, motility and adhesiveness of SW480 colon carcinoma cells were significantly enhanced by TMPRSS4 overexpression. Furthermore, overexpression of TMPRSS4 induced loss of E-cadherin-mediated cell–cell adhesion, concomitant with the induction of SIP1/ZEB2, an E-cadherin transcriptional repressor, and led to epithelial–mesenchymal transition events, including morphological changes, actin reorganization and upregulation of mesenchymal markers. TMPRSS4-overexpressing cells also displayed markedly increased metastasis to the liver in nude mice upon intrasplenic injection. Taken together, these studies suggest that TMPRSS4 controls the invasive and metastatic potential of human cancer cells by facilitating an epithelial–mesenchymal transition; TMPRSS4 may be a potential therapeutic target for cancer treatment.

Bis(2-phenyl-ethyl-ammonium) tetra-chloridocobaltate(II).

Crystals of the title compound, (C6H5CH2CH2NH3)2[CoCl4], were grown by the solvent-evaporation method. This inorganic–organic hybrid compound exhibits a layered structure in which isolated CoCl4 inorganic layers alternate with bilayers of phenylethylammonium cations. Although the inorganic anion is zero-dimensional, the layered structure is stabilized via N—H⋯Cl hydrogen bonds. The CoCl4 tetrahedra connect to the cations through N—H⋯Cl hydrogen bonds, building a two-dimensional network extending parallel to (010).

Effect of hydrogen bond in hexamethylenetetramine–MOH (M=Li, Na, K) complexes

Abstract 14N NQR and IR spectra of the hexamethylenetetramine(HMT)–MOH complexes (M=Li, Na, and K) were investigated at room temperature. NQR lines were assigned to two (for LiOH and NaOH complexes) and three (for KOH complex) inequivalent nitrogen sites. The frequency shift is accounted for redistribution of the charges because of the charge transfer, and the line broadening is deduced from the difference of electronegativity between the charge donor and acceptor in the hydrogen bond. For the IR spectra, there are deformations of CNC bond owing to the hydrogen bond of nitrogen in HMT with OH in MOH and the direct bonding of nitrogen with alkali metal (Li, Na, and K) ion. In view of the deformation of the CNC bond in HMT molecules from the IR results one may propose that the most important part of polarization produced by the crystalline field in the HMT complexes is the electronic polarization.

A series of long-chain lamellar hydrated copper(II) alkylsulfonates with different chain molecular assemblies

Reaction of copper(II) salts with n-alkylsulfonate anions yields light blue lamellar Cu(C(n)H(2n + 1)SO3)2 x zH2O displaying distinct (mono/bi-layer) chain packing with increasing alkyl chain lengths. This may be attributed to the amphiphilic nature of the surfactants, i.e., the hydrophilic sulfonate head groups, mediating the coordination, and H-bonding interactions, and the hydrophobic alkyl chains.