Inhibition of sucrose-isomaltase expression by EGF in the human colon adenocarcinoma cells Caco-2

1991 ◽  
Vol 261 (6) ◽  
pp. C1173-C1183 ◽  
Author(s):  
H. S. Cross ◽  
A. Quaroni
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Marked Reduction ◽  
Transforming Growth Factor ◽  
Colon Adenocarcinoma ◽  
Human Colon ◽  
Mrna Levels ◽  
Proliferation And Differentiation ◽  
Epidermal Growth ◽  
Human Colon Adenocarcinoma

To investigate the role and mechanism of action of epidermal growth factor (EGF) in the intestinal epithelium, we have studied its influence on proliferation and differentiation of Caco-2 cells, a human colon adenocarcinoma cell line exhibiting several characteristics of adult small intestinal enterocytes. A clone of Caco-2 cells synthesizing minimal amounts of transforming growth factor-alpha (TGF-alpha)/epidermal growth factor (EGF)-like activity was used in these studies. Cells grown in the presence of 20-200 ng EGF/ml exhibited increased DNA synthesis and proliferation; formation of morphologically poorly differentiated multilayers was observed at 200 ng EGF/ml. At all concentrations tested EGF produced a significant and marked reduction in sucrase activity, whereas other brush-border enzymes (aminopeptidase N, alkaline phosphatase, dipeptidylpeptidase IV) were only marginally affected. EGF influenced sucrase expression at two different levels. At 20 ng/ml, it affected primarily sucrase-isomaltase processing in the endoplasmic reticulum and/or increased its degradation. At 200 ng EGF/ml, a significant and marked reduction in sucrase-isomaltase mRNA levels and biosynthesis was observed. These results demonstrated that EGF has important and selective effects on Caco-2 cell proliferation and differentiation and may affect different cellular activities depending on its concentration.

scholarly journals Regulation of cytokine production in the human thymus: epidermal growth factor and transforming growth factor alpha regulate mRNA levels of interleukin 1 alpha (IL-1 alpha), IL-1 beta, and IL-6 in human thymic epithelial cells at a post-transcriptional level.

1991 ◽  
Vol 174 (5) ◽  
pp. 1147-1157 ◽  
Author(s):  
P T Le ◽  
S Lazorick ◽  
L P Whichard ◽  
B F Haynes ◽  
K H Singer
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Transforming Growth Factor ◽  
Interleukin 1 ◽  
Thymic Epithelial Cells ◽  
Transforming Growth Factor Alpha ◽  
Mrna Levels ◽  
Epidermal Growth ◽  
Factor Alpha

Human thymic epithelial (TE) cells produce interleukin 1 alpha (IL-1 alpha), IL-1 beta, and IL-6, cytokines that are important for thymocyte proliferation. The mRNAs for these cytokines are short-lived and are inducible by multiple stimuli. Thus, the steady-state levels for IL-1 and IL-6 mRNAs are critical in establishing the final cytokine protein levels. In this study we have evaluated the effect of epidermal growth factor (EGF), a growth factor for TE cells, and its homologue transforming growth factor alpha (TGF-alpha), on primary cultures of normal human TE cells for the levels of IL-1 alpha, IL-1 beta, IL-6, and TGF-alpha mRNA. We showed that TE cells expressed EGF receptors (EGF-R) in vitro and in vivo, and that treatment of TE cells with EGF or TGF-alpha increased IL-1 and IL-6 biological activity and mRNA levels for IL-1 alpha, IL-1 beta, and IL-6. Neither EGF nor TGF-alpha increased transcription rates of IL-1 alpha, IL-1 beta, and IL-6 genes, but rather both EGF and TGF-alpha increased cytokine mRNA stability. By indirect immunofluorescence assay, TGF-alpha was localized in medullary TE cells and thymic Hassall's bodies while EGF-R was localized to TE cells throughout the thymus. Thus, TGF-alpha and EGF are critical regulatory molecules for production of TE cell-derived cytokines within the thymus and may function as key modulators of human T cell development in vivo.

scholarly journals Clonal analysis of sucrase-isomaltase expression in the human colon adenocarcinoma Caco-2 cells

1991 ◽  
Vol 280 (3) ◽  
pp. 599-608 ◽  
Author(s):  
J F Beaulieu ◽  
A Quaroni
Keyword(s):  
Growth Factor ◽  
Culture Medium ◽  
Transforming Growth Factor ◽  
Colon Adenocarcinoma ◽  
Human Colon ◽  
Human Colon Carcinoma Cell ◽  
Cell Proliferation And Differentiation ◽  
Cell Clones ◽  
Proliferation And Differentiation ◽  
Clonal Cell Lines

To investigate the biosynthetic basis for the mosaic expression of brush border enzymes in confluent Caco-2 cells, a human colon carcinoma cell line exhibiting characteristics of adult small intestinal enterocytes, we have obtained a series of clones differing markedly in their growth rates, amounts of transforming growth factor-alpha/epidermal growth factor-like activity released into the culture medium, and sucrase-isomaltase (SI) activity. Other intestinal markers (aminopeptidase N, dipeptidylpeptidase IV, lactase, alkaline phosphatase and ‘crypt cell antigen’) displayed a much more limited variability in expression, suggesting that the Caco-2 cell clones we have obtained did not differ in their overall ability to differentiate. Immunofluorescence staining, metabolic labelling with radioactive methionine and hybridization analysis of SI mRNA abundance were used to investigate SI synthesis and its regulation in clones endowed with low, intermediate or high sucrase activity. The results obtained have demonstrated heterogeneous SI expression, even in clonal cell lines, and a negative correlation between SI expression and growth factor concentrations in the culture medium, suggesting an autocrine regulation of cell proliferation and differentiation in confluent Caco-2 cells. Pulse-chase experiments using the two clones endowed with the lowest and highest levels of SI activity, followed by immunoprecipitation of labelled SI with epitope-specific antibodies and SDS/PAGE analysis, suggested that both transcriptional and post-translational mechanisms play a role in the regulation of SI expression in intestinal cells.

115 RAT EPIDERMAL GROWTH FACTOR GENE EXPRESSION CONTROLLED BY PROGESTERONE DURING PREGNANCY

2008 ◽  
Vol 20 (1) ◽  
pp. 138
Author(s):  
H.-S. Byun ◽  
S.-H. Ko ◽  
G.-S. Lee ◽  
S.-H. Hyun ◽  
E.-B. Jeung
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Expression Patterns ◽  
Uterine Wall ◽  
Mrna Levels ◽  
Heparin Binding ◽  
Pregnant Rats ◽  
Epidermal Growth

The implantation of the developing blastocyst into the uterine wall is regulated by a precisely timed interplay of the ovarian hormones estrogen and progesterone, which control a set of regulatory factors that make the uterus receptive to implantation. These factors include EGF receptor (Egfr) and members of the epidermal growth factor (Egf) family, namely, EGF, heparin-binding EGF (Hbegf), transforming growth factor-alpha (Tgfa), and amphiregulin (Areg). However, the exact role(s) these factors play in pregnancy remain unclear. To address this, a group of three rats was euthanized every day from gestation day (GD) 0 through to GD21. The uterus, attached uterus (these tissues are mostly composed of stromal cells), and placenta were rapidly excised and used directly for total RNA. We used real-time PCR with the TaqMan system (Applied Biosystems, Foster City, CA, ISA) to examine the uterine expression patterns of these factors in rats during the entire pregnancy. Data were analyzed by nonparametric one-way analysis of variance using the Kruskal-Wallis test, followed by Dunnett's test for multiple comparisons. Egf and Egfr mRNA levels increased significantly at implantation, especially on GD3 and GD6, after which their expression gradually decreased. Hbegf and Tgfa showed a modest spike of transcription around the implantation period (GD4 and GD3, respectively) but were much more strongly expressed at mid-pregnancy, which is when progesterone is secreted at high levels. Areg expression peaked strongly around implantation (GD4) and at mid-pregnancy (GD12). Treatment of pregnant rats on GD5 or GD8 with the progesterone receptor antagonist RU486 (2.5 mg per rat) blocked the expression of all of the genes on the days of treatment. Moreover, injection of immature rats with progesterone induced the uterine expression of all of the genes except Hbegf, while injection with estrogen or estrogen plus progesterone had no effect. Taken together, all genes tested may be assumed to regulate the implantation process. Moreover, Hbegf, Tgfa, and Areg may participate during mid-pregnancy. In addition, all of these activities are likely to be controlled by progesterone in the uterus of rats during pregnancy.

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