Soluble form of carbonic anhydrase IX (CAIX) in transitional cell carcinoma of urinary tract.

We investigated the expression of cell-associated CAIX protein in histological sections of the transitional cell carcinoma (TCC) of the urinary tract and of the soluble form of CAIX (s-CAIX) shed by the tumor into the serum and urine of TCC patients. A total of 23 patients with histologically confirmed TCC or squamous cell carcinoma (SCC) were enrolled in the pilot study. Sixteen healthy individuals served as controls.

Carbonic anhydrase IX (CA IX) mediates tumor cell interactions with microenvironment.

Expression of CA IX is normally restricted to the mucosa of alimentary tract, but on the other hand, it takes place in a high percentage of human cancers derived from tissues which are normally CA IX-negative. It is a transmembrane protein with two extracellular domains: carbonic anhydrase (CA) with a high catalytic activity and a proteoglycan-like segment (PG), mediating cell-cell adhesion. Both CA and PG domains interact with the microenvironment and they could play a role in tumorigenesis, but their roles are poorly understood.

Soluble form of carbonic anhydrase IX (CA IX) in the serum and urine of renal carcinoma patients.

Tumour-associated protein carbonic anhydrase IX (CA IX) has two major forms. One is a cell-associated, transmembrane protein seen on Western blots as a twin band of 54/58 kDa, expressed in gastric mucosa and in several types of cancer. The other is a soluble protein s-CA IX of 50/54 kDa, which is released into the culture medium or into the body fluids, most likely by proteolytic cleavage of the extracellular part from transmembrane and intracellular sequences.

Gastric hyperplasia in mice with targeted disruption of the carbonic anhydrase gene Car9.

Background & Aims: Carbonic anhydrase (CA) IX is a highly active enzyme with adhesion capacity that is functionally implicated in acid-base balance and intercellular communication. It is normally present in basolateral membranes of gastrointestinal epithelial cells and ectopically expressed in various carcinomas. To show its physiologic relevance, we have cloned the Car9 gene and generated CA IX-deficient mice.

Human tumour-associated cell adhesion protein MN/CA IX: identification of M75 epitope and of the region mediating cell adhesion.

MN/CA IX is a cell surface protein, strongly associated with several types of human carcinomas. It exerts activity of carbonic anhydrase and capacity of binding to cell surface receptors. In the present work, we used affinity purified MN/CA IX protein to demonstrate that the cells adhere to immobilized MN/CA IX and that the monoclonal antibody M75 abrogates cell attachment to MN/CA IX.

Identification of MaTu-MX agent as a new strain of lymphocytic choriomeningitis virus (LCMV) and serological indication of horizontal spread of LCMV in human population.

In this study we elucidated the molecular character of MaTu-MX, previously described as an unusual transmissible agent. Amino acid sequencing of peptides generated from a 58-kDa MX-related protein purified from MaTu human carcinoma cells allowed us to identify it as a nucleoprotein (NP) of lymphocytic choriomeningitis virus (LCMV). Northern blot analysis detected LCMV-specific RNAs in MaTu cells.

Transient transformation of mammalian cells by MN protein, a tumor-associated cell adhesion molecule with carbonic anhydrase activity.

The MN protein is associated with certain human carcinomas, but absent in most normal tissues. It is a transmembrane protein; its extracellular part contains a domain homologous with carbonic anhydrases (CAs) and a proteoglycan-like region. In the present study, we observed that cells (human CGL1 and mouse NIH3T3 cells) transfected with MN cDNA showed morphologic transformation, but reverted to normal phenotype after 4-5 weeks.

Expression of MaTu-MN protein in human tumor cultures and in clinical specimens.

MaTu is a novel agent which may be of relevance in human oncogenesis, and has 2 components. One of them, the exogenous MX (coding for protein p58X), is transmissible to human fibroblasts, to HeLa and to HeLa x fibroblast (H/F) hybrids. The other component, MN, is a cellular gene.

A novel quasi-viral agent, MaTu, is a two-component system.

MaTu is a quasi-viral agent presumably derived from a human mammary tumor. In some respects it resembles classical viruses and in some the "slow viruses," and in others it is different from both. Using monoclonal antibodies (Mabs), we showed that it is a two-component system.

An unusual transmissible agent--MaTu.

MaTu is an agent, believed to be derived from a human mammary carcinoma, which displayed several extraordinary properties. These were: RIP and PAGE revealed in MaTu-infected cells only a single protein band of Mr 58 k, the gp 58. This gp 58 was immunoprecipitated by antibodies present in some human sera as well as in some sera of rabbits, sheep, and cattle.

Rescued human virus (RHV): association with melanoma.

RHV, which is presumably a defective human retrovirus, has been recovered from the human melanoma cell line HMB2. In the presence of Moloney mouse leukemia virus (MLV), used as a helper, RHV is serially transmissible in mouse NIH-3T3 cells and can provide envelope antigens for vesicular stomatitis virus pseudotype--VSV(RHV). This pseudotype is neutralizable with an inhibitor, present in all human sera tested; the inhibitory activity is resistant to heating at 100 degrees C.

Rescue of presumptive viral information from human cells by a helper oncovirus.

We have attempted to rescue presumptive human endogenous retrovirus(es) by using a competent animal oncovirus as a helper. Human melanoma cells (line HMB2) were fused, using polyethylene glycol, with mouse NIH-3T3 cells which had been infected and transformed by the Harvey murine leukaemia and sarcoma virus complex (MLV and MSV). The heteropolykaryons obtained were co-cultivated with fresh NIH-3T3 cells; filtered (Millipore 0.

Monoclonal antibody against an antigen selectively assembled into vesicular stomatitis virus virions from HeLa cells.

A mouse hybridoma cell line IIB9, secreting IgG2b antibody specific for a HeLa cell antigen, was obtained by fusion of a mouse myeloma cell line with spleen cells from mice immunized with purified VSV tsO45 mutant (defective in assembly of G protein) which had been reproduced at a non-permissive temperature in HeLa cells. The monoclonal antibody IIB9 was strictly specific for HeLa cells in two tests: (1) reaction with VSV or Chandipura virus phenotypically mixed with host cell antigen, (2) complement-dependent cytotoxicity test (51Cr-release).

Human cell surface proteins selectively assembled into vesicular stomatitis virus virions.

Vesicular stomatitis virus (VSV) selectively assembled proteins from human cells into progeny virions. These proteins can be surface labeled before infection with 125I, and when purified virus was examined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, only two or three bands of proteins (Mr around 100K) were seen. Antisera to these proteins were produced, using as immunizing antigen VSV tsO45 mutant, defective in assembly of G protein, which had been made at the nonpermissive temperature in the three human tumor cell lines, HeLa (cervical carcinoma), T47D (breast carcinoma), and HMB2 (melanoma).

Vesicular stomatitis virus phenotypically mixed with retroviruses: an efficient detection method.

Two methods of assaying vesicular stomatitis virus (VSV) particles phenotypically mixed with retrovirus-coded antigens were compared. Each of them detected phenotypically mixed particles with different minimum proportion of surface glycoprotein molecules of the donor virus, and consequently also profoundly different proportions of VSV virions containing retrovirus antigens. Only a low proportion (10(-4) of VSV virions grown in XMuLV-infected rabbit SIRC cells behaved as pseudotypes, resistant to anti-VSV serum and neutralized by anti-XMuLV serum.

Pseudotypes of vesicular stomatitis virus with coat antigen of bovine leukaemia virus--VSV (BLV): antigenic surface mosaic and the roles of precipitating antibodies and polycations.

The pseudotype particles vesicular stomatitis virus (bovine leukaemia virus) [VSV (BLV)] contain a surface antigenic mosaic, composed of both VSV- and BLV-specific antigens, as demonstrated by increased neutralization by anti-VSV serum after addition of complement or of "second antibody". All the pseudotype infectivity was precipitated by VSV-specific antibody: it could be pelleted by low-speed centrifugation and its infectivity recovered without any loss by sonication. Polycations present during adsorption had little effect on infectivity of the pseudotype for Vero cells, but markedly increased its titre for chicken fibroblasts.

A rapid neutralization test for antibodies to bovine leukemia virus, with the use of rhabdovirus pseudotypes.

Two rhabdoviruses, vesicular stomatitis (type Indiana) and Chandipura viruses, formed pseudotype particles with envelope antigens provided by bovine leukemia virus (BLV). The pseudotypes are infectious for calf, human, mink, and rat cells, but the most sensitive indicator proved to be the Vero cells. Infectivity of the pseudotypes was increased by DEAE-dextran present during adsorption.

Pseudotype particles of vesicular stomatitis virus with surface antigens of bovine leukaemia virus--VSV (BLV) -- as a sensitive probe for detecting antibodies in the sera of spontaneously infected cattle.

Phenotypically mixed particles containing the genome of vesicular stomatitis virus (VSV) and envelope antigen corresponding to bovine leukaemia virus (BLV) -- the VSV (BLV) pseudotypes -- can be employed as a rapid, specific and sensitive probe for detecting BLV-neutralizing antibodies in bovine sera.

Comparison of the sensitivity to ultraviolet irradiation of reovirus 3 and some viruses of the Kemerovo group.

The kinetics of UV inactivation of the tick-borne Kemerovo (strain R-10) and Lipovnik (strain Lip-91) viruses which have been preliminarily classified as possible members of the Reovirus group was examined. Reovirus 3 and Sindbis virus served as reference double-stranded RNA and single-stranded RNA viruses, respectively. The parameters of UV inresembled those of Reovirus 3.