Action of exo- and endo-type cellulases from Irpex lacteus on Valonia cellulose

Cellulolytic mode of action of the two highly purified exo- and endo-type cellulases from Irpex lacteus on pure Valonia cellulose was investigated. Electron microscopy substantiated that both cellulases are adsorbed preferentially into the internal parts of microfibrils in the network structure of the cellulose at initial stages before enzymatic hydrolysis, and that the adsorption ratio of both cellulases onto the external surfaces of microfibrils increased with incubation time although this tendency was less remarkable with the exo-type cellulase than with the endo-type one. The exo-type cellulase exhibited relatively high activity producing cellobiose throughout 12-h incubation, while the endo-type cellulase produced small amounts of cellooligosaccharides. The degree of polymerization was far more suppressed by the endo-type cellulase than by the exo-type one. Degradation by the cellulases in typical exo- and endo-fashions yielded quite different morphological patterns in the microfibrils. Exo-type cellulase loosened the network structure of microfibrils and made them slightly thinner, while endo-type cellulase caused conspicuous swelling and dissolution of individual microfibrils.     

Adsorption mode of exo- and endo-cellulases from Irpex lacteus (Polyporus tulipiferae) on cellulose with different crystallinities.

The adsorption mode of two highly purified cellulases, exo- and endo-type cellulases, from Irpex lacteus (Polyporus tulipiferae) was investigated by using pure cellulosic materials with different crystallinity as substrates. Adsorption of the two enzymes on the substrates was found to fit the Langmuir-type adsorption isotherm. Maximum amount of adsorbed enzyme obtained from the Langmuir plots showed an inverse correlation to the crystallinity of the substrate with both enzymes, and this value of endo-type cellulase was less dependent on the degree of crystallinity of substrates than that of exo-type cellulase, whose isotherms reached saturation in the range of low enzyme concentrations. The two enzymes showed relatively high affinities for all the substrates and their affinities increased with increasing crystallinity, but this tendency was less marked with endo-type cellulase than with exo-type one. In addition, large negative values of free energy change were observed on the adsorption of both enzymes, and the values became more negative with increasing crystallinity. Consequently, both cellulases showed high adsorption on crystalline cellulose and the adsorption process became smoother with increasing crystallinity. The adsorption of the two types of cellulases was endothermic with an increase in entropy, especially for amorphous cellulose, suggesting the occurrence of water release from the substrates during enzyme adsorption. In addition, the changes in thermodynamic parameters (delta H, delta S, and delta G) in adsorption of exo-type cellulase were larger than in that of endo-type enzyme.     

Aflatoxin B1 Up-Regulates Insulin Receptor Substrate 2 and Stimulates Hepatoma Cell Migration

Aflatoxin B1 (AFB1) is a potent carcinogen that can induce hepatocellular carcinoma. AFB1-8,9-exo-epoxide, one of AFB1 metabolites, acts as a mutagen to react with DNA and induce gene mutations, including the tumor suppressor p53. In addition, AFB1 reportedly stimulates IGF receptor activation. Aberrant activation of IGF-I receptor (IGF-IR) signaling is tightly associated with various types of human tumors. In the current study, we investigated the effects of AFB1 on key elements in IGF-IR signaling pathway, and the effects of AFB1 on hepatoma cell migration. The results demonstrated that AFB1 induced IGF-IR, Akt, and Erk1/2 phosphorylation in hepatoma cell lines HepG2 and SMMC-7721, and an immortalized human liver cell line Chang liver. AFB1 also down-regulated insulin receptor substrate (IRS) 1 but paradoxically up-regulated IRS2 through preventing proteasomal degradation. Treatment of hepatoma cells and Chang liver cells with IGF-IR inhibitor abrogated AFB1-induced Akt and Erk1/2 phosphorylation. In addition, IRS2 knockdown suppressed AFB1-induced Akt and Erk1/2 phosphorylation. Finally, AFB1 stimulated hepatoma cell migration. IGF-IR inhibitor or IRS2 knockdown suppressed AFB1-induced hepatoma cell migration. These data demonstrate that AFB1 stimulates hepatoma cell migration through IGF-IR/IRS2 axis.     

beta-Galactosidase and its significance in ripening of "Saijyo" Japanese Persimmon fruit

The fruit extracts of ripening cv. Japanese Persimmon, "Saijyo", contained a number of glycosidases and glycanases. Among them, beta-galactosidase appeared to be the most significant, and the activity increased in parallel with tissue ripening. Persimmon beta-galactosidase was presented in at least three isoforms, beta-galactosidase-I (pI = 4.88), beta-galactosidase-II (pI = 6.76), and beta-galactosidase-III (pI = 7.05). beta-Galactosidase-III had exo-type galactanase activity, while the others did not. The activity of endo-type glycanases was a maximum in immature green or yellow fruits. The firmness of the pulp tissue decreased dramatically, and the amount of water-soluble polysaccharide (WSS) increased. The enzyme activities of exo-type glycosidases, especially beta-galactosidase, appeared maximal in mature red fruits. The amount of extractable pectin remained unchanged, although the galactose content of the high-molecular-weight fraction in WSS decreased dramatically. These results suggest that the ripening of persimmon was caused by the solubilization of pectic polysaccharide by endo-type glycanases and digestion by exo-type glycosidases. beta-Galactosidase, in particular, seemed to play a major role in ripening the fruit.     

Triterpene-enriched extracts from Ganoderma lucidum inhibit growth of hepatoma cells via suppressing protein kinase C,activating mitogen-activated protein kinases and G2-phase cell cycle arrest

The medicinal mushroom Ganoderma lucidum (G. lucidum) has been used in the Orient for the prevention and treatment of various diseases including cancer. Except for the immune enhancing properties of its polysaccharide constituent, very little is known about the anticancer activity of another major constituent, triterpenes. In this report, we studied the anticancer mechanism of triterpene-enriched extracts from G. lucidum. The triterpene-enriched fraction, WEES-G6, was prepared from mycelia of G. lucidum by sequential hot water extraction, removal of ethanol-insoluble polysaccharides and then gel-filtration chromatography. We found that WEES-G6 inhibited growth of human hepatoma Huh-7 cells, but not Chang liver cells, a normal human liver cell line. Treatment with WEES-G6 caused a rapid decrease in the activity of cell growth regulative protein, PKC, and the activation of JNK and p38 MAP kinases. The changes in these molecules resulted in a prolonged G2 cell cycle phase and strong growth inhibition. None of these effects were seen in the normal liver cells. Our findings suggest that the triterpenes contained in G. lucidum are potential anticancer agents.     

Histone deacetylase inhibition by sodium valproate regulates polarization of macrophage subsets

Recent studies suggest that change of macrophage phenotype (M1/M2) is associated with autoimmune diseases. Sodium valproate (VPA) is a class I histone deacetylase (HDAC) inhibitor, which has immunomodulatory function in graft-versus-host disease. However, its impact on macrophage polarization has not been defined. We evaluated the effects of VPA on both mouse macrophage cell line RAW264.7 and primary mouse bone marrow macrophages (BMMs). Exposure to VPA significantly repressed the production of interleukin 12 (IL-12), and tumor necrosis factor α by lipopolysaccharide (LPS)-induced macrophage activation, in contrast, promoted IL-10 expression. VPA also affected the costimulatory molecule expression on LPS-stimulated RAW264.7 and BMMs (downregulation of CD40 and CD80, and upregulation of CD86). Specifically, VPA inhibited macrophage-mediated T helper 1 (Th1) effector but enhanced Th2 effector cell activation. Together, our preclinical study demonstrates that VPA significantly affects the phenotype and function of macrophage, indicating an important role of HDAC activity in immune regulation and inflammation. It also provides a rationale to evaluate VPA activity for the treatment of macrophage dysfunction-associated diseases.     

A human-mouse hybrid cell line that stably expresses chemotaxis to N-formylmethionyl-leucyl-phenylalanine

Human leukocytes, which contain monocytes and neutrophils that exhibit chemotaxis to fMet-Leu-Phe, were fused with the mouse macrophage RAW264-TG3 cell line, which exhibits chemotaxis to endotoxin-activated mouse serum but not to fMet-Leu-Phe. From such fusions twelve cell lines were isolated, all of which migrated to endotoxin-activated mouse serum. Four of the cell lines also exhibited chemotaxis to fMet-Leu-Phe, and of these cell lines, only one, WBC264-9, retained the capacity to migrate to fMet-Leu-Phe after culture for 20 or more passages. Determination of the number of chromosomes and analysis of the electrofocusing patterns of human and mouse hypoxanthine-guanine phosphoribosyltransferase activity showed that WBC264-9 was derived from a human-mouse cell fusion. WBC264-9, a stable macrophage cell line that exhibits chemotaxis to fMet-Leu-Phe, provides a model system to investigate attractant-specific biochemical reactions.     

Heparin-released triglyceride lipase from chang liver cells

Heparin-released triglyceride lipase (TGL) from Chang liver cells (ATCC CCL 13) was investigated using very low density lipoproteins (VLDL) as a substrate. The TGL activity was released into the culture medium when the cells were incubated with heparin. The enzyme showed maximum activity at pH 8.5, and 80% inhibition by 0.6 M NaCl. These results indicated that Chang liver cells, a cell line derived from liver, synthesize lipoprotein lipase.     

Identification and characterization of monoclonal antibodies specific for macrophages at intermediate stages in the tumoricidal activation pathway

Macrophage activation for tumor cell killing is a multistep pathway in which responsive macrophages interact sequentially with priming and triggering stimuli in the acquisition of full tumoricidal activity. A number of mediators have been identified which have activating capability, including in particular IFN-gamma and bacterial LPS. Although the synergistic functional response of normal macrophages to sequential incubation with these activation signals has been well-established, characterization of the intermediate stages in the activation pathway has been difficult. We have developed a model system for examination of various aspects of macrophage activation, through the use of the murine macrophage tumor cell line, RAW 264.7. These cells, like normal macrophages, exhibit a strict requirement for interaction with both IFN-gamma and LPS in the development of tumor cytolytic activity. In addition, these cells can be stably primed by the administration of gamma-radiation. In the studies reported here, we have used RAW 264.7 cells treated with IFN-gamma alone or with IFN-gamma plus LPS to stimulate the production of rat mAb probes recognizing cell surface changes occurring during the activation process. In this way we have identified three Ag associated with intermediate stages of the activation process. One Ag, TM-1, is expressed on RAW 264.7 cells primed by IFN-gamma or gamma-radiation. This surface Ag thus identifies cells at the primed cell intermediate stage of the tumoricidal activation pathway regardless of the mechanism of activation. A second Ag, TM-2, is expressed on IFN-treated RAW 264.7 cells but not on RAW 264.7 cells primed with gamma-radiation alone. Expression of this Ag can be induced by treatment of irradiated cells with IFN-gamma, but is not induced by IFN-gamma treatment of a noncytolytic cell line, WEHI-3. This Ag thus appears to be an IFN-inducible cell surface protein associated specifically with macrophage activation for tumoricidal activity. Finally, Ag TM-3 is detectable on RAW 264.7 cells primed by either IFN-gamma or gamma-radiation, after subsequent triggering of the primed cells with LPS. The addition of the mAb recognizing this antigen to the function assay of tumor cell killing can inhibit they lytic activity of both triggered cells. Thus, this Ag may play a role in the antitumor effector functions of activated macrophages. Overall, the results suggest that these mAb can serve as useful tools for identification of molecules associated with the process of macrophage activation for tumor cell killing.     

Expression of the mammalian c-fes protein in hematopoietic cells and identification of a distinct fes-related protein.

The avian c-fps and mammalian c-fes proto-oncogenes are cognate cellular sequences. Antiserum raised against the P140gag-fps transforming protein of Fujinami avian sarcoma virus specifically recognized a 92,000-Mr protein in human and mouse hematopoietic cells which was closely related in structure to Snyder-Theilen feline sarcoma virus P87gag-fes. This polypeptide was apparently the product of the human c-fes gene and was therefore designated p92c-fes. Human p92c-fes was associated with a tyrosine-specific protein kinase activity in vitro and was capable of both autophosphorylation and phosphorylation of enolase as an exogenous protein substrate. The synthesis of human and mouse p92c-fes was largely, though not entirely, confined to myeloid cells. p92c-fes was expressed to relatively high levels in a multipotential murine myeloid cell line, in more mature human and mouse granulocyte-macrophage progenitors, and in differentiated macrophage like cells as well as in the mononuclear fraction of normal and leukemic human peripheral blood. p92c-fes was not found in erythroid cells, with the exception of a human erythroleukemia line which retains the capacity to differentiate into macrophage like cells. These results suggest a normal role for the p92c-fes tyrosine kinase in hematopoiesis, particularly in granulocyte-macrophage differentiation. In addition, a distinct 94,000-Mr polypeptide, antigenically related to p92c-fes, was identified in a number of hematopoietic and nonhematopoietic human and mouse cells and was also found to be associated with a tyrosine-specific protein kinase activity.     

Elimination of B-RAF in Oncogenic C-RAF-expressing Alveolar Epithelial Type II Cells Reduces MAPK Signal Intensity and Lung Tumor Growth

Tumors are often greatly dependent on signaling cascades promoting cell growth or survival and may become hypersensitive to inactivation of key components within these signaling pathways. Ras and RAF mutations found in human cancer confer constitutive activity to these signaling molecules thereby converting them into an oncogenic state. RAF dimerization is required for normal Ras-dependent RAF activation and is required for the oncogenic potential of mutant RAFs. Here we describe a new mouse model for lung tumor development to investigate the role of B-RAF in oncogenic C-RAF-mediated adenoma initiation and growth. Conditional elimination of B-RAF in C-RAF BxB-expressing embryonic alveolar epithelial type II cells did not block adenoma formation. However, loss of B-RAF led to significantly reduced tumor growth. The diminished tumor growth upon B-RAF inactivation was due to reduced cell proliferation in absence of senescence and increased apoptosis. Furthermore, B-RAF elimination inhibited C-RAF BxB-mediated activation of the mitogenic cascade. In line with these data, mutation of Ser-621 in C-RAF BxB abrogated in vitro the dimerization with B-RAF and blocked the ability to activate the MAPK cascade. Taken together these data indicate that B-RAF is an important factor in oncogenic C-RAF-mediated tumorigenesis.     

Differential effects of liposome-incorporation on liver macrophage activating potencies of rough lipopolysaccharide, lipid A, and muramyl dipeptide. Differences in susceptibility to lysosomal enzymes

We investigated the in vitro activation of rat liver macrophages to a tumor-cytotoxic state with muramyl dipeptide (MDP), rough LPS (Re-LPS) and lipid A in both a free and liposome-encapsulated form. The tumor cytotoxic state of the liver macrophages was determined with a [methyl-3H]thymidine release assay using C26 colon adenocarcinoma cells as target cells. As was shown previously, the encapsulation of MDP within multi-lamellar phospholipid vesicles greatly enhanced the activating potency of the drug; by contrast, encapsulation of Re-LPS or lipid A significantly reduced the activation of macrophages as compared to the free form of these agents. At a dose of 1 ng of free Re-LPS per ml a significant induction of tumor cell lysis was observed whereas a maximal level was obtained at a concentration of approximately 10 ng/ml. By encapsulation of Re-LPS in liposomes the activating potency diminished 20- to 100-fold. The minimal concentration required to induce detectable macrophage activation with free lipid A was 10 ng/ml, while liposome-encapsulated lipid A did not induce any detectable tumor cell lysis up to a concentration of 200 ng/ml. After a 1-h pre-incubation with a lysosomal fraction from rat liver at pH 4.8, the macrophage-activating potency of Re-LPS and lipid A was diminished by up to 95% whereas MDP remained fully active under these conditions. We conclude that, due to endocytic uptake of liposome-incorporated Re-LPS and lipid A and subsequent intralysosomal degradation, these immunomodulators are inactivated with respect to their potency to activate liver macrophages to tumor cytotoxicity.     

Modulation of macrophage function by gamma-irradiation. Acquisition of the primed cell intermediate stage of the macrophage tumoricidal activation pathway

Macrophage activation for tumor cell killing is a multistep pathway in which responsive macrophages interact sequentially with priming and triggering stimuli in the acquisition of full tumoricidal activity. Although this synergistic response of normal macrophages to sequential incubation with activation signals has been well established, characterization of the intermediate stages in this pathway has been difficult, due in large measure to the instability of the intermediate cell phenotypes. We have developed a model system for examination of macrophage-mediated tumor cell lysis, with the use of the murine macrophage tumor cell line RAW 264.7. These cells, like normal macrophages, exhibit a strict requirement for interaction with both interferon-gamma (IFN-gamma, the priming signal) and bacterial lipopolysaccharide (LPS, the triggering signal) in the development of tumor cytolytic activity. In this system, the priming effects of IFN-gamma decay rapidly after withdrawal of this mediator and the cells become unresponsive to LPS triggering. We have recently observed that gamma-irradiation of the RAW 264.7 cells also results in development of a primed activation state for tumor cell killing. The effects of gamma-radiation on the RAW 264.7 cell line are strikingly similar to those resulting from incubation with IFN-gamma, with the exception that the irradiation-induced primed cell intermediate is stable and responsive to LPS triggering for at least 24 hr. Treatment with gamma-radiation also results in increased cell surface expression of major histocompatibility complex-encoded class I antigens; however, class II antigen expression is not induced. Irradiation-induced development of the primed phenotype is not solely the result of cytostatic effects as treatment of the cells with a radiomimetic drug, mitomycin C, results in decreases in [3H]thymidine incorporation that are similar to those observed after irradiation, without concomitant development of cytolytic potential. In addition, priming by gamma-radiation does not appear to be mediated by the release of soluble autoregulatory factors. This alternate pathway for induction of the primed macrophage activation state should serve as a useful tool for identification of molecules important to the functional potential of primed cells, and for elucidation of the biochemical mechanisms of the priming event in tumoricidal activation.     

Plectin deficiency in liver cancer cells promotes cell migration and sensitivity to sorafenib treatment

Plectin involved in activation of kinases in cell signaling pathway and plays important role in cell morphology and migration. Plectin knockdown promotes cell migration by activating focal adhesion kinase and Rac1-GTPase activity in liver cells. Sorafenib is a multi-targeting tyrosine kinase inhibitor that improves patient survival on hepatocellular carcinoma. The aim of this study is to investigate the correlation between the expression of plectin and cell migration as well as the sensitivity of hepatoma cell lines exposing to sorafenib. Hepatoma cell lines PLC/PRF/5 and HepG2 were used to examine the level of plectin expression and cell migration in comparison with Chang liver cell line. In addition, sensitivity of the 3 cell lines to sorafenib treatment was also measured. Expression of plectin was lower in PLC/PRF/5 and HepG2 hepatoma cells than that of Chang liver cells whereas HepG2 and PLC/PRF/5 cells exhibit higher rate of cell migration in trans-well migration assay. Immunohistofluorecent staining on E-cadherin revealed the highest rate of collective cell migration in HepG2 cells and the lowest was found in Chang liver cells. Likewise, HepG2 cell line was most sensitive to sorafenib treatment and Chang liver cells exhibited the least sensitivity. The drug sensitivity to sorafenib treatment showed inverse correlation with the expression of plectin. We suggest that plectin deficiency and increased E-cadherin in hepatoma cells were associated with higher rates of cell motility, collective cell migration as well as higher drug sensitivity to sorafenib treatment.     

Design,Synthesis, and In Vitro and In Vivo Biological Studies of a 3′-Deoxythymidine Conjugate that Potentially Kills Cancer Cells Selectively

Thymidine kinases (TKs) have been considered one of the potential targets for anticancer therapeutic because of their elevated expressions in cancer cells. However, nucleobase analogs targeting TKs have shown poor selective cytotoxicity in cancer cells despite effective antiviral activity. 3′-Deoxythymidine phenylquinoxaline conjugate (dT-QX) was designed as a novel nucleobase analog to target TKs in cancer cells and block cell replication via conjugated DNA intercalating quinoxaline moiety. In vitro cell screening showed that dT-QX selectively kills a variety of cancer cells including liver carcinoma, breast adenocarcinoma and brain glioma cells; whereas it had a low cytotoxicity in normal cells such as normal human liver cells. The anticancer activity of dT-QX was attributed to its selective inhibition of DNA synthesis resulting in extensive mitochondrial superoxide stress in cancer cells. We demonstrate that covalent linkage with 3′-deoxythymidine uniquely directed cytotoxic phenylquinoxaline moiety more toward cancer cells than normal cells. Preliminary mouse study with subcutaneous liver tumor model showed that dT-QX effectively inhibited the growth of tumors. dT-QX is the first molecule of its kind with highly amendable constituents that exhibits this selective cytotoxicity in cancer cells.     

RETRACTED ARTICLE: Immunotherapy of metastatic colorectal cancer with vitamin D-binding protein-derived macrophage-activating factor,GcMAF

Serum vitamin D binding protein (Gc protein) is the precursor for the principal macrophage-activating factor (MAF). The MAF precursor activity of serum Gc protein of colorectal cancer patients was lost or reduced because Gc protein is deglycosylated by serum α-N-acetylgalactosaminidase (Nagalase) secreted from cancerous cells. Deglycosylated Gc protein cannot be converted to MAF, leading to immunosuppression. Stepwise treatment of purified Gc protein with immobilized β-galactosidase and sialidase generated the most potent macrophage-activating factor (GcMAF) ever discovered, but it produces no side effect in humans. Macrophages treated with GcMAF (100 pg/ml) develop an enormous variation of receptors and are highly tumoricidal to a variety of cancers indiscriminately. Administration of 100 nanogram (ng)/human maximally activates systemic macrophages that can kill cancerous cells. Since the half-life of the activated macrophages is approximately 6 days, 100 ng GcMAF was administered weekly to eight nonanemic colorectal cancer patients who had previously received tumor-resection but still carried significant amounts of metastatic tumor cells. As GcMAF therapy progressed, the MAF precursor activities of all patients increased and conversely their serum Nagalase activities decreased. Since serum Nagalase is proportional to tumor burden, serum Nagalase activity was used as a prognostic index for time course analysis of GcMAF therapy. After 32–50 weekly administrations of 100 ng GcMAF, all colorectal cancer patients exhibited healthy control levels of the serum Nagalase activity, indicating eradication of metastatic tumor cells. During 7 years after the completion of GcMAF therapy, their serum Nagalase activity did not increase, indicating no recurrence of cancer, which was also supported by the annual CT scans of these patients.     

Commensal Bacteria-induced Interleukin 1β (IL-1β) Secreted by Macrophages Up-regulates Hepcidin Expression in Hepatocytes by Activating the Bone Morphogenetic Protein Signaling Pathway

The liver hormone hepcidin is the central regulator of systemic iron metabolism. Its increased expression in inflammatory states leads to hypoferremia and anemia. Elucidation of the mechanisms that up-regulate hepcidin during inflammation is essential for developing rational therapies for this anemia. Using mouse models of inflammatory bowel disease, we have shown previously that colitis-associated hepcidin induction is influenced by intestinal microbiota composition. Here we investigate how two commensal bacteria, Bifidobacterium longum and Bacteroides fragilis, representative members of the gut microbiota, affect hepcidin expression. We found that supernatants of a human macrophage cell line infected with either of the bacteria up-regulated hepcidin when added to a human hepatocyte cell line. This activity was abrogated by neutralization of IL-1β. Moreover, purified IL-1β increased hepcidin expression when added to the hepatocyte line or primary human hepatocytes and when injected into mice. IL-1β activated the bone morphogenetic protein (BMP) signaling pathway in hepatocytes and in mouse liver, as indicated by increased phosphorylation of small mothers against decapentaplegic proteins. Activation of BMP signaling correlated with IL-1β-induced expression of BMP2 in human hepatocytes and activin B in mouse liver. Treatment of hepatocytes with two different chemical inhibitors of BMP signaling or with a neutralizing antibody to BMP2 prevented IL-1β-induced up-regulation of hepcidin. Our results clarify how commensal bacteria affect hepcidin expression and reveal a novel connection between IL-1β and activation of BMP signaling. They also suggest that there may be differences between mice and humans with respect to the mechanism by which IL-1β up-regulates hepcidin.     

Expression of liver and placental alkaline phosphatases in Chang liver cells

This paper presents evidence that a protein characteristic of differentiated liver cells, liver alkaline phosphatase, is synthesized by the Chang liver cell line. Liver alkaline phosphatase was demonstrated by immumochemical assay, ³²P-labeling and polyacrylamide gel electrophoresis, immunofluorescence microscopy, and the fluorescence-activated cell sorter. The synthesis of the liver enzyme by the Chang liver cells is interpreted to indicate fidelity of the Chang cells to their origin from human liver tissue. Chang liver cells also synthesize a phosphatase which is similar if not indentical to the placental alkaline phosphatase. Since a placental-type alkaline phosphatase has been observed in a number of non-trophoblastic cell lines and also in some neoplasms, it does not seem reliable as an index of the origins of the cell line. Because of the claims that Chang liver cells are actually HeLa cells, HeLa cells were studied in tandem with the Chang cells. The results showed that the HeLa cells do not make the liver type phosphatase. The data are discussed in relation to the question of HeLa cell contamination of the Chang cell line and the validity of criteria normally used to identify cell lines.     

Design,synthesis and structure–activity relationships of novel biarylamine-based Met kinase inhibitors

Biarylamine-based inhibitors of Met kinase have been identified. Lead compounds demonstrate nanomolar potency in Met kinase biochemical assays and significant activity in the Met-driven GTL-16 human gastric carcinoma cell line. X-ray crystallography revealed that these compounds adopt a bioactive conformation, in the kinase domain, consistent with that previously seen with 2-pyridone-based Met kinase inhibitors. Compound 9b demonstrated potent in vivo antitumor activity in the GTL-16 human tumor xenograft model.