Clinical usefulness of cell-free and concentrated ascites reinfusion therapy (CART) in combination with chemotherapy for malignant ascites: a post-marketing surveillance study

International Journal of Clinical Oncology - Cell-free and concentrated ascites reinfusion therapy (CART) has been suggested to be able to treat malignant ascites more safely and effectively with...     

Purification and Characterization of Tumor Invasion-inhibiting Factors

Tumor invasion-inhibiting factors were purified from bovine liver using an in vitro system for estimating the tumor invasion ability. The acid-ethanol extract of liver was subjected to ultrafiltration (Amicon PM10 membrane), and the fraction corresponding to the molecular weight range below 10,000 was further fractionated by ion-exchange (DEAE-Toyopearl), gel filtration (Bio-Gel P6), and reverse-phase (C18) chromatographies. Two types of active polypeptides with molecular weights of about 5,000 and 2,000 were purified and named IIF-1 and IIF-2, respectively. Both peptides inhibited tumor invasion with half-maximum concentrations of 2–6 ng/ml in vitro . The amino acid compositions of both peptides were determined.     

Effects of Methylthiodeoxyadenosine and Its Analogs on in vitro Invasion of Rat Ascites Hepatoma Cells and Methylation of Their Phospholipids

The relationship between tumor invasiveness in vitro and methyiation of plasma membrane phospholipids was investigated. For this purpose, two hepatoma cell lines, Cl-30 and LC-AH, were used which show specific penetration to below cultured monolayers of mesothelial cells from rat mesentery and endothelial cells from calf pulmonary artery, respectively. Methylthiodeoxyadenosine (MTA) and five of its analogs, difluoro-MTA, deoxyadenosine, sinefungin, phenylthiodeoxyadenosine and fluorophenylthiodeoxyadenosine, inhibited the invasion of the tumor cells without affecting their proliferation. This inhibition was associated with reduction in the incorporation of radioactivity of [methyl-3H]methionine into cellular phosphatidylethanolamine derivatives without changes in the labelings of RNA and DNA and carboxylmethylation of protein. These compounds also decreased the membrane fluidity of the tumor cells, measured by a steady-state fluorescence polarization method. Three other MTA analogs (fluorodideoxyadenosine, fluoroazidodideoxyadenosine and flnoroamino-dideoxyuridine) did not affect the invasiveness of the tumor cells or alter their phospholipid methyiation or membrane fluidity at concentrations that did not inhibit proliferation. These results suggest that the decrease in invasiveness of tumor cells by MTA and its analogs is due to alterations in the phospholipid composition and fluidity of the tumor cell membranes.     

A novel Arg-Gly-Asp containing peptide specific for platelet aggregation and its effect on tumor metastasis: a possible mechanism of RGD peptide-mediated inhibition of tumor metastasis.

A novel cyclic tetrapeptide containing L-arginine-glycine-L-aspartic acid-L-phenylglycine (cyclo-RGDPhg) was synthesized and found to be a potent inhibitor of platelet aggregation induced by highly metastatic murine squamous cell carcinoma (SCCVII) cells (IC50 = 3.3 microM) as well as ADP (1.5 microM). This cyclic peptide, however, showed similar or less inhibitory activities on adhesion of SCCVII cells to fibronectin, vitronectin and type IV collagen as compared with those of parent linear tetrapeptide, RGDS. These results show that cyclo-RGDPhg peptide is a highly specific antagonist for gpIIb/IIIa on platelets. Moreover, this peptide failed to suppress pulmonary metastasis of SCCVII cells in an experimental metastasis model. These results indicate that RGD peptide-mediated inhibition of tumor metastasis is attributed to the suppression of cell adhesion but not platelet aggregation. These also suggest that platelet aggregation is not an essential step during blood circulation of tumor cells for the completion of metastasis.     

Tumor invasion-inhibiting factor 2: primary structure and inhibitory effect on invasion in vitro and pulmonary metastasis of tumor cells.

The primary structure of tumor invasion-inhibiting factor 2 (IIF-2) purified from bovine liver (A. Isoai et al., Jpn. J. Cancer Res., 81:909-914, 1990) was determined. A computer homology search of the National Biomedical Research Foundation data bank revealed that IIF-2 is identical to the carboxyl-terminal region, residue number [69-89], of high mobility group 17 which is a DNA-binding non-histone protein. IIF-2 synthesized by an automated peptide synthesizer showed similar invasion-inhibitory activity as compared with the purified factor, when tested with the monolayer invasion assay system using highly invasive rat ascites tumor cells. When examined with the other in vitro assay systems using a modified Boyden chamber, the synthetic IIF-2 suppressed the chemotactic migration of highly metastatic B16 melanoma (B16FE7) cells to fibronectin or laminin and invasion through Matrigel. The IIF-2 inhibited neither the cell proliferation nor the binding of cells to fibronectin or Matrigel and also showed no significant inhibition of Mr 90,000 type IV collagenase (gelatinase) obtained from human schwannoma (YST-3) cells. The formation of lung colonies in mice given injections of B16FE7 and Lewis lung carcinoma cells was significantly reduced by the coinjection of the IIF-2. These results suggest that IIF-2 suppresses tumor invasion by impairing cell motility and inhibits the migration of metastasizing cells through extracellular matrix (extravasation steps) following their arrest in the capillary bed of the lung in vivo.     

Effects of methylthiodeoxyadenosine and its analogs on in vitro invasion of rat ascites hepatoma cells and methylation of their phospholipids

The relationship between tumor invasiveness in vitro and methylation of plasma membrane phospholipids was investigated. For this purpose, two hepatoma cell lines, C1-30 and LC-AH, were used which show specific penetration to below cultured monolayers of mesothelial cells from rat mesentery and endothelial cells from calf pulmonary artery, respectively. Methylthiodeoxyadenosine (MTA) and five of its analogs, difluoro-MTA, deoxyadenosine, sinefungin, phenylthiodeoxyadenosine and fluorophenylthiodeoxyadenosine, inhibited the invasion of the tumor cells without affecting their proliferation. This inhibition was associated with reduction in the incorporation of radioactivity of [methyl-3H]methionine into cellular phosphatidylethanolamine derivatives without changes in the labelings of RNA and DNA and carboxylmethylation of protein. These compounds also decreased the membrane fluidity of the tumor cells, measured by a steady-state fluorescence polarization method. Three other MTA analogs (fluorodideoxyadenosine, fluoroazidodideoxyadenosine and fluoroaminodideoxyuridine) did not affect the invasiveness of the tumor cells or alter their phospholipid methylation or membrane fluidity at concentrations that did not inhibit proliferation. These results suggest that the decrease in invasiveness of tumor cells by MTA and its analogs is due to alterations in the phospholipid composition and fluidity of the tumor cell membranes.     

Detection of caspase-9 activation in the cell death of the Bcl-x-deficient mouse embryo nervous system by cleavage sites-directed antisera

Caspases, which play crucial roles during apoptosis, are activated from their inactive proforms in a sequential cascade of cleavage by other members of the caspase family. Caspase-9 is autoprocessed by the Apaf-1/cytochrome c pathway and acts at an early point in this cascade, whereas Bcl-xL, an antiapoptotic member of the Bcl-2 family, prevents activation of caspases in vitro. Little is known, however, about the relation between caspase-9 and Bcl-xL during development of the mammalian nervous system. We used antisera against two cleavage sites in mouse caspase-9 that recognize only the activated form of mouse caspase-9, and we examined immunohistochemically the activation of mouse caspase-9 in the nervous system of Bcl-x-deficient mouse embryos. Mouse caspase-9 is processed at both D(353) and D(368), but it is processed preferentially at D(368) during apoptosis of cultured cells induced by various stimuli and in the nervous system of Bcl-x-deficient mouse embryos. We show that Bcl-xL protects against caspase-9- and/or caspase-3-dependent apoptosis in the caudal portion of the ventral hindbrain, anterior horn cells, and dorsal root ganglia neurons of the normal mouse embryos and against caspase-9/caspase-3-independent apoptosis in the dorsal region of the nervous system including the dorsal spinal cord. Furthermore, we demonstrate that Bcl-xL blocks cytochrome c release from mitochondria, causing activation of caspase-9 in anterior horn cells and dorsal root ganglia neurons in mouse embryos at embryonic day 11.5.     

Two endoplasmic reticulum-associated degradation (ERAD) systems for the novel variant of the mutant dysferlin: ubiquitin/proteasome ERAD(I) and autophagy/lysosome ERAD(II)

Dysferlin is a type-II transmembrane protein and the causative gene of limb girdle muscular dystrophy type 2B and Miyoshi myopathy (LGMD2B/MM), in which specific loss of dysferlin labeling has been frequently observed. Recently, a novel mutant (L1341P) dysferlin has been shown to aggregate in the muscle of the patient. Little is known about the relationship between degradation of dysferlin and pathogenesis of LGMD2B/MM. Here, we examined the degradation of normal and mutant (L1341P) dysferlin. Wild-type (wt) dysferlin mainly localized to the ER/Golgi, associated with retrotranslocon, Sec61alpha, and VCP(p97), and was degraded by endoplasmic reticulum (ER)-associated degradation system (ERAD) composed of ubiquitin/proteasome. In contrast, mutant dysferlin spontaneously aggregated in the ER and induced eukaryotic translation initiation factor 2alpha (eIF2alpha) phosphorylation and LC3 conversion, a key step for autophagosome formation, and finally, ER stress cell death. Unlike proteasome inhibitor, E64d/pepstatin A, inhibitors of lysosomal proteases did not stimulate the accumulation of the wt-dysferlin, but stimulated aggregation of mutant dysferlin in the ER. Furthermore, deficiency of Atg5 and dephosphorylation of eIF2alpha, key molecules for LC3 conversion, also stimulated the mutant dysferlin aggregation in the ER. Rapamycin, which induces eIF2alpha phosphorylation-mediated LC3 conversion, inhibited mutant dysferlin aggregation in the ER. Thus, mutant dysferlin aggregates in the ER-stimulated autophagosome formation to engulf them via activation of ER stress-eIF2alpha phosphorylation pathway. We propose two ERAD models for dysferlin degradation, ubiquitin/proteasome ERAD(I) and autophagy/lysosome ERAD(II). Mutant dysferlin aggregates on the ER are degraded by the autophagy/lysosome ERAD(II), as an alternative to ERAD(I), when retrotranslocon/ERAD(I) system is impaired by these mutant aggregates.     

Purification and characterization of tumor invasion-inhibiting factors

Tumor invasion-inhibiting factors were purified from bovine liver using an in vitro system for estimating the tumor invasion ability. The acid-ethanol extract of liver was subjected to ultrafiltration (Amicon PM10 membrane), and the fraction corresponding to the molecular weight range below 10,000 was further fractionated by ion-exchange (DEAE-Toyopearl), gel filtration (Bio-Gel P6), and reverse-phase (C18) chromatographies. Two types of active polypeptides with molecular weights of about 5,000 and 2,000 were purified and named IIF-1 and IIF-2, respectively. Both peptides inhibited tumor invasion with half-maximum concentrations of 2-6 ng/ml in vitro. The amino acid compositions of both peptides were determined.