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Biomedical subjects

M C Gutierrez

Publications and source records attributed to M C Gutierrez.

7 recordsLinked to original sources

Modulation of the antigenic phenotype of human breast carcinoma cells by modifiers of protein kinase C activity and recombinant human interferons.

In the present study we have analyzed the effect of a synthetic protein kinase C (PKC) activator 3-(N-acetylamino)-5-(N-decyl-N-methylamino)-benzyl alcohol (ADMB) and the natural PKC-activating tumor-promoting agents 12-O-tetradecanoylphorbol 13-acetate (TPA) and mezerein on the antigenic phenotype of T47D human breast carcinoma cells. All three agents increased the surface expression of the tumor-associated antigen BCA 225 and various cellular antigens, including HLA class II antigens, intercellular adhesion molecule 1 (ICAM-1) and c-erbB-2. Expression of the same antigens was also upregulated to various extents in T47D cells by recombinant fibroblast (IFN beta) and immune (IFN gamma) interferon. Shedding of BCA 225 from T47D cells was induced by TPA, mezerein, IFN beta and IFN gamma, whereas ADMB did not display this activity. The ability of ADMB, TPA and mezerein to modulate the antigenic phenotype of T47D cells appears to involve a PKC-mediated pathway, since the PKC inhibitor, H-7, eliminates antigenic modulation. In contrast, the ability of IFN beta and IFN gamma to enhance the synthesis, expression and shedding of BCA 225, as well as to enhance HLA class II antigens, c-erbB-2 and ICAM-1 expression, was either unchanged or modestly reduced by simultaneous exposure to H-7. Analysis of steady-state mRNA levels for HLA class I antigens, HLA class II-DR beta antigen, ICAM-1 and c-erbB-2 indicated that the ability of H-7 to inhibit expression of these antigens in TPA-, mezerein- and ADMB-treated cells was not a consequence of a reduction in the steady-state levels of mRNAs for these antigens. The results of the present investigation indicate that the biochemical pathways mediating enhanced antigenic expression in T47D cells induced by TPA, mezerein and the synthetic PKC activator ADMB are different from those induced by recombinant interferons. Furthermore, up-regulation of antigenic expression in T47D cells can occur by a PKC-dependent or a PKC-independent pathway.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine

Biosynthesis and partial amino acid sequence of the human NDA4 antigen. An activation antigen common to B and T cell lineages.

NDA4, a cell surface protein of molecular mass 46 kDa common to activated peripheral blood B and T cells, plays a unique role in the control of B and T cell maturation. NDA4 inhibits B and T cell activation, as mitogen-stimulated B and T cell blastogenic responses are decreased in the presence of mAb NDA4, the antibody recognizing NDA4. After mitogen-activation, however, the regulatory function of NDA4 changes. Addition of mAb NDA4 to cultures of Staphylococcus aureus Cowan strain A-activated B cells or alloreactive T cell clones stimulates their proliferation. NDA4 epitopes are conserved across primate species lines and are present on transformed cells of neuroectodermal origin. NDA4 is synthesized as a molecular mass 50 kDa precursor and is processed to a mature 46 kDa form within 30 min. The NDA4 Ag also exists as soluble forms of 40 and 42 kDa. The membrane and soluble forms of NDA4 have been purified to homogeneity and sequenced by N-terminal Edman degradation.

Amino Acid Sequence

Postlymphography linear dermatitis.

Cutaneous effects secondary to lymphography are rare events. We herein report a patient with Hodgkin's disease who developed a linear dermatitis in both lower limbs 6 days after a pedal lymphography. Histopathologic examination of the lesions demonstrated a subacute dermatitis. Patch tests with the substances used in the lymphography yielded negative results. We discuss the possible pathogenic mechanisms of this striking linear dermatitis.

Adult

Experimental maternal hyperpipecolatemia decreases DNA in the mouse brain.

Pipecolic acid represents the major metabolite of lysine in the CNS. This study aimed to mimic the known pathological condition of hyperpipecolatemia in human neonates by maintaining high and steady concentrations in the mouse brain both pre- and postnatally. Although histological observations did not reveal any abnormal findings in the brain, liver and kidney, the offsprings of mothers which were injected during pregnancy with 250 mg/kg PA presented a significant decrease in both cortical and whole brain DNA content. Protein, RNA and CNPase activity were not altered. The changes in DNA content are of particular interest since they demonstrate that a high and steady level of pipecolic acid, which is comparable to the level seen in human hyperpipecolatemic brain, can induce a neurotoxic effect in the fetal mouse brain. Mice injected with the same dose from day 1 to day 29 after birth did not show any change in DNA content in the cortex. These results suggest that the critical period from pipecolic acid neurotoxic effect is prenatal, probably due to a selective vulnerability of developing neurons to high levels of pipecolic acid. The decrease in DNA concentration induced by maternal hyperpipecolatemia suggests a neurotoxic effect of pipecolic acid on cell proliferation during fetal development which could be related to the neuronal damage observed in the brain of hyperpipecolatemic neonates.

2',3'-Cyclic-Nucleotide Phosphodiesterases

Increased surface expression and shedding of tumor associated antigens by human breast carcinoma cells treated with recombinant human interferons or phorbol ester tumor promoters.

In the present study we have evaluated the effect of recombinant interferons, including leukocyte (IFN-alpha A), fibroblast (IFN-beta) and immune (IFN-gamma), and the tumor promoting agent 12-0-tetradecanoyl-phorbol-13-acetate (TPA) on the expression of tumor associated antigens (TAA) and class II HLA-DR antigens on human breast carcinoma cell lines. The effect of these agents on the shedding of a high molecular weight tumor associated glycoprotein, BCA-225, was also determined. All three interferons and TPA enhanced the expression of the Mr 180,000 carcinoembryonic antigen (CEA) and CEA-related TAA recognized by monoclonal antibody B1.1 in both T47D and MCF-7 human breast carcinoma cell lines. The three types of interferons and TPA differed in their absolute TAA-augmenting ability, even in single-cell subclones derived from MCF-7 cells and previously shown to display a differential susceptibility to IFN-alpha augmentation of B1.1 expression. In general, IFN-gamma was more effective than IFN-alpha, IFN-beta or TPA in augmenting the expression of TAA, CEA and BCA-225, and HLA-DR expression in T47D and MCF-7 cells. Differences were also apparent in the ability of the three interferon preparations and TPA to induce shedding of BCA-225 in T47D and MCF-7 cells and their subclones. As observed with TAA expression, IFN-gamma was the most effective preparation in inducing TAA shedding. IFN-gamma also induced the expression and the shedding of BCA-225 by a subclone of T47D cells, T47D cl 17, which normally displays a reduced expression of BCA-225 and does not spontaneously shed this TAA without exposure to IFN-gamma. Recombinant leukocyte interferon (IFN-alpha A) also enhanced BCA-225 expression on T47D cells grown as xenografts in nude mice in vivo. The results of the present study emphasize the complexity of potential antigenic responses which can be induced in human breast carcinoma cells when they are exposed to biological response modulators, including different types of interferon, and tumor promoting agents, such as TPA. This investigation also indicates that both classes of agents can differentially augment expression and/or shedding of TAA by specific breast carcinoma cell lines as well as subclones derived from the same breast carcinoma cell line.

Antibodies, Monoclonal