1,720,983 research outputs found
Espressione cadmio-dipendente di AEG-1, c-fos e c-jun in cellule tumorali mammarie umane
No full textShort-term exposure to cadmium affects the expression of stress response- and apoptosis-related genes in immortalized epithelial cells from the human breast
No full textIt is known that cadmium (Cd) evokes cell responses that not only involve protective reactions against toxicity but also induces cell death. Increasing interest has been recently focused on the elucidation of the cellular and molecular aspects of Cd-dependent regulation of gene expression in different model systems. Here, we examined the effects of short-term (24h) exposure of immortalized non-tumoral HB2 cells from human breast epithelium to CdCl(2) at 50 microM concentration, corresponding to the IC(50) for this time of incubation. The possible occurrence of apoptosis-related events was evaluated via analysis of the physical state of the DNA and of the membrane localization of phosphatydilserine. We also checked the pattern of expression of stress response genes, such as those coding for heat shock proteins and metallothioneins, and of genes coding for factors and enzymes involved in the onset of apoptosis. Our results indicate that although metal treatment appears to induce a non-apoptotic type of cell death, Cd can be also regarded as an active transcriptional modulator for this cell line
Type V collagen regulates the expression of apoptotic and stress response genes by breast cancer cells
Full text linkType V collagen is a "minor" component of normal human breast stroma, which is subjected to over-deposition in cases of ductal infiltrating carcinoma (DIC). We reported that, if used as a culture substrate for the DIC cell line 8701-BC, it exhibited poorly-adhesive properties and restrained the proliferative and motile behavior of the cell subpopulation able to attach onto it. Moreover, this collagen species was able to trigger DNA fragmentation and impair survival of 8701-BC cells. In this study, we have extended our investigation with the aim to obtain further evidence that the death induced by type V collagen was of the apoptotic type by (i) microscopic detection and quantitation of Apoptag-labeled cells, (ii) analysis of the expression levels of selected genes coding for apoptosis-linked factors, caspases, and stress-response proteins by conventional and semi-quantitative multiplex PCR, and (iii) evaluation of the extent of caspase activation by chromogenic assay. We report here that type V collagen is able to determine an increase in the percentage of Apoptag-positive cells, to up-regulate Bcl-xS, Bad, Dap kinase, hsf-1, mthsp75, caspase-1, -5, -8, -9, and -14, whilst down-regulating Bcl-2, Bcl-xbeta, and hsp60. Treatment of cell lysates with chromogenic tetrapeptide substrates specific for caspase-1, -5, -8, and -9 demonstrated a marked increase of enzymatic activity in the presence of type V collagen. Our data validate 8701-BC cell line as a suitable "in vitro" model for further and more detailed studies on the molecular mechanisms of the death response induced by type V collagen on primary DIC cells
Collagen-induced differential expression of an RNA polymerase subunit by breast cancer cells
Full text linkIt was previously reported that the stroma of ductal infiltrating carcinoma (DIC) of the human breast contains considerable amount of an embryo-foetal collagen type, OF/LB (onco-foetal/laminin-binding), and that adhesion of 8701-BC DIC cells onto OF/LB collagen substrates selectively promotes cell growth, motility, production of extracellular lytic enzymes and invasion "in vitro" if compared with other collagen species. To detect possible transcriptional differences for regulatory proteins following OF/LB collagen-cell interactions, we submitted RNA preparations from 8701-BC cells grown on collagen type I, IV and OF/LB to "differential display"-PCR in the presence of degenerate C(2)H(2) zinc finger and protein tyrosine kinase domain oligonucleotide primers. We report that growth of 8701-BC cells on OF/LB collagen is consistently associated with the up-regulation of hRPB17 gene, coding for an RNA polymerase subunit, as confirmed by conventional RT-PCR and Northern analyses
Mid-region PTHrP and gene expression of MDA-MB231 breast cancer cells
No full textType V collagen is known to be over-deposited in the stroma of ductal infiltrating carcinomas of the breast. When used as a substrate, type V collagen restrains growth and invasion, and affects gene expression of 8701-BC ductal infiltrating carcinomas cells. Here we supplement existing data by demonstrating type V collagen dependent upregulation of capn2 gene expression in 8701-BC cells through differential display-PCR and Western blot assays. Furthermore, we suggest that our data obtained by centrifugal sedimentation and electrophoresis strongly suggest a correlation between calpain overproduction and DNA fragmentation, since the incubation with calpain inhibitor partly reverts the latter
PTHrP [38-94] is a survival- and growth-promoting factor for non-tumoral breast epithelial cells.
No full text
Type V collagen-induced upregulation of capn2 (large subunit of m-calpain) gene expression and DNA fragmentation in 8701-BC breast cancer cells
No full textType V collagen is known to be over-deposited in the stroma of ductal infiltrating carcinomas of the breast. When used as a substrate, type V collagen restrains growth and invasion, and affects gene expression of 8701-BC ductal infiltrating carcinomas cells. Here we supplement existing data by demonstrating type V collagen dependent upregulation of capn2 gene expression in 8701-BC cells through differential display-PCR and Western blot assays. Furthermore, we suggest that our data obtained by centrifugal sedimentation and electrophoresis strongly suggest a correlation between calpain overproduction and DNA fragmentation, since the incubation with calpain inhibitor partly reverts the latter
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