Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The DF3 antigen is a member of a family of high molecular weight glycoproteins aberrantly expressed in malignant mammary epithelium. We have generated a monoclonal antibody (MAb), designated DF3-P, against a recombinant DF3/beta-galactosidase fusion protein. Characterization of this MAb has demonstrated reactivity with immature precursors of DF3 antigen and not with the secreted form. These findings are in contrast to those obtained with MAb DF3, a previously described antibody with predominant reactivity against the mature glycoprotein. The finding that deglycosylation of secreted DF3 antigen with neuraminidase and endo-alpha-N-acetylgalactosaminidase is associated with increased MAb DF3-P reactivity provided additional support for the selectivity of this antibody against the protein core. Epitope mapping studies demonstrate that both the DF3-P and DF3 epitopes are located at a TRPAPGS domain in the 20-amino acid tandem repeat. The results of competition studies with synthetic peptides indicate that the proline in this domain is involved in both epitopes, while the potential glycosylation sites at threonine and serine may contribute to the differential reactivity of MAbs DF3 and DF3-P. Taken together, these findings suggest that both antibodies react with a similar epitope that is modified by the presence of carbohydrate moieties. The results of immunoperoxidase staining studies further demonstrate that while MAb DF3-P reacts with formalin-fixed sections of breast carcinomas, this antibody exhibits little if any reactivity with normal mammary epithelium. Selective expression of the DF3-P epitope in malignant breast cells may be useful in identifying this transformed phenotype.
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PMID:Tumor selective reactivity of a monoclonal antibody prepared against a recombinant peptide derived from the DF3 human breast carcinoma-associated antigen. 137 71

Absorption of dietary energy, nitrogen, carbohydrates and calcium, and retention of nitrogen and calcium were studied in 20 children with protein-energy malnutrition of the edematous type, using metabolic balance techniques and breath H2 analysis, to assess the advisability of using lactose-containing formulas in the rehabilitation of severely malnourished children. Ten patients received for 45 days a diet formula based on cows' milk (intact milk) and 10 similar children received the same formula pretreated with beta-galactosidase to hydrolyze the lactose (hydrolyzed milk). Dietary intakes were gradually increased to reach, on the 8th day, 4 g of protein and 150 kcal/kg. There were no differences between groups with respect to absorption or retention of the index nutrients. Postprandial carbohydrate malabsorption was occasionally observed in two patients with servings of the intact milk formula, and in one with the hydrolyzed milk diet. When the nutritional quality of a diet is assessed, the amount of nutrients that are absorbed and utilized are more important than the small, incompletely absorbed fractions that do not have significant metabolic or clinical implications. Therefore, the use of milk as the protein source for recovery diets is not contraindicated in the routine treatment of PEM.
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PMID:The effect of dietary lactose on the early recovery from protein-energy malnutrition. II. Indices of nutrient absorption. 643 95

We have tested the reactivity of the monoclonal antibodies submitted to the ISOBM TD-4 Workshop for reactivity with a hybrid molecule consisting of the bacterial beta-galactosidase and most of the extracellular nonrepeat domain of MUC1/episialin. Two monoclonal antibodies submitted to the Workshop, 232A1 and M29, were directed against the protein moiety of this domain as shown by immunoblotting and immunoprecipitation.
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PMID:Monoclonal antibodies against the nonmucin domain of MUC1/episialin. 942 90

Adenoviruses are efficient gene delivery agents for a variety of neoplasms. In the present study, we have investigated the use of adenoviruses for the delivery of the thymidine kinase (tk) gene into multiple myeloma (MM) cells. We first demonstrated that MM cell lines and MM patient cells express both adenovirus receptors as well as the DF3/MUC1 protein, thus providing a rationale for using adenoviruses to selectively deliver genes under the control of the DF3 promoter. By using an adenoviral construct containing beta-galactosidase (beta-gal) gene driven by the DF3 promoter (Ad. DF3-betagal), we demonstrate greater than 80% transduction efficiency in OCI-My5 and RPMI 8226 MM cell lines at a multiplicity of infection of 1 to 100. Importantly, transduction with the tk gene driven by the DF3 promoter (Ad.DF3-tk) followed by treatment with 50 micromol/L ganciclovir (GCV) purged >/=6 log of contaminating OCI-My5 and RPMI 8226 MM cells within bone marrow mononuclear cells. In contrast, normal human hematopoietic progenitor cell number was unaffected under these conditions. Selectivity of DF3/MUC1 promoter was further confirmed, because Ad.DF3-betagal or Ad.DF3-tk did not transduce MUC1-negative HeLa cervical carcinoma cells. In addition, GCV treatment of Ad.DF3-tk-transduced RPMI 8226 MM cells did not induce a significant bystander effect. These findings demonstrate that transduction with Ad vectors using a tumor-selective promoter provides a highly efficient and selective approach for the ex vivo purging of MM cells.
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PMID:Adenovirus vector-based purging of multiple myeloma cells. 984 25

Primary cultures of human mammary epithelial cells underwent significant morphological and functional changes during the aging process between passage 12 (P12) and passage 16 (P16). Concomitant with a progressive and significant expression of senescence-associated beta-galactosidase as aging marker, the cells restructured their attachment, increased in size and ceased to divide. Young HMEC until P11 demonstrated a nearly 100% expression of distinct adhesion molecules such as CD24, integrin beta1 (CD29) and CD44 similar to the human mammary tumor cell line MCF-7. In parallel with the aging-associated alterations of the cell adhesion, expression of CD24 and CD44 dropped in senescent P16 HMECs. However, levels of CD29 remained unchanged during the aging process. The tumor-associated Muc-1 (CD227), which was expressed to about 100% in the tumorigenic MCF-7 cells, was detectable in 51% of young HMEC in P11 and declined to 37% in aged HMEC in P16. In association with the remodeling of cell shape, expression levels of distinct matrix metalloproteinases including MMP-7 markedly decreased in aging HMEC. In contrast, MMP-1, MMP-2 and MMP-9 remained unchanged indicating a possible functional role of MMP-7 during the HMEC aging process. Indeed, down-modulation of MMP-7 by RNAi revealed a significantly elevated G(2)/M cell cycle arrest and a 2- to 3-fold enhanced senescence-associated beta-galactosidase expression as compared to control siRNA transfectants and control HMEC, respectively. Together, these findings suggested that decreasing MMP-7 expression contributes to accelerated aging of human mammary epithelial cells.
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PMID:MMP-7 is involved in the aging of primary human mammary epithelial cells (HMEC). 1820 46