Search results for "silencing"
showing 10 items of 253 documents
Transforming Growth Factor-β–Mediated Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Expression and Apoptosis in Hepatoma Cells Requires Fun…
2008
Abstract Transforming growth factor-β (TGF-β) has been shown to induce apoptotic cell death in normal and transformed hepatocytes. We recently identified tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as an important mediator of TGF-β–induced apoptosis in hepatoma cells. In this study, we have further explored the mechanism by which TGF-β up-regulates TRAIL expression. The 5′-flanking region of the TRAIL gene was isolated and characterized. Deletion mutants of the 5′-untranslated region of the TRAIL gene revealed a region comprising nucleotides −1950 to −1100 responsible for TRAIL induction following treatment with TGF-β. Within this region, we have identified an activator …
IFN-alpha-induced apoptosis in hepatocellular carcinoma involves promyelocytic leukemia protein and TRAIL independently of p53.
2009
Abstract IFNs are pleiotropic cytokines that have been shown to be important regulators of cell growth. IFN-α has recently been recognized to harbor therapeutic potential in prevention and treatment of hepatocellular carcinoma (HCC). However, HCC cells respond differentially to IFN treatment, the mechanism of which is largely unknown. To address this issue, we analyzed the effect of IFN-α on different liver tumor cell lines. We found that growth inhibiting effects of IFN-α in hepatoma cells require PML-NB induction and, moreover, tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) expression on the mRNA and protein level. RNAi silencing of PML down-regulates TRAIL expression in …
Nupr1-Aurora Kinase A Pathway Provides Protection against Metabolic Stress-Mediated Autophagic-Associated Cell Death
2012
Abstract Purpose: The limited supply of oxygen and nutrients is thought to result in rigorous selection of cells that will eventually form the tumor. Experimental Design: Nupr1 expression pattern was analyzed in human tissue microarray (TMA) and correlated with survival time of the patient. Microarray analysis was conducted on MiaPaCa2 cells subjected to metabolic stress in Nupr1-silenced conditions. DNA repair and cell cycle–associated gene expression was confirmed by real-time quantitative PCR (qRT-PCR). Nupr1 and AURKA protective role were analyzed using RNA interference (RNAi) silencing or overexpression. DNA damage and autophagy were analyzed by Western blot analysis and immunofluoresc…
Downregulation of RhoB GTPase confers resistance to cisplatin in human larygneal carcinoma cells
2009
Acquired resistance to cisplatin represents a major obstacle to an efficient chemotherapy. We found downregulation of RhoB expression in cisplatin-resistant tumor cell lines from different origin. In cisplatin-resistant laryngeal carcinoma subline overexpression of farnesylated or geranylgeranylated RhoB increased cisplatin-induced cell death, while silencing of RhoB expression diminished sensitivity of parental HEp-2 cells via decreased cellular accumulation of cisplatin. However, since RhoB silencing in additional tumor cell lines did not alter their sensitivity to cisplatin, we can assume that RhoB downregulation does not provide general protective role in cell response to cisplatin. Nev…
pap, reg I? andreg I? mRNAs are concomitantly up-regulated during human colorectal carcinogenesis
1999
We have established the phenotype of a colorectal tumor by partial sequencing of 2166 transcripts that were eventually arrayed on high-density filters. These filters were used for differential screening with mRNAs of colorectal cancer and normal adjacent mucosa to characterize genes whose expression is altered in colorectal carcinoma. Three genes encoding related proteins, PAP, reg Iα and reg Iβ, were over-expressed in cancer. Northern-blot analysis confirmed that their expression was very low in normal colonic epithelial cells, but elevated in 75% of tumors. Western blotting with specific antibodies to pap and reg Iα revealed in tumors a single band of the expected size (15–16 kDa), demons…
PO-053 The phospholipase ddhd1 as a new target in colorectal cancer therapy
2018
Introduction We have recently demonstrated that Citrus-limon derived nanovesicles are able to decrease colon cancer cell viability and that this effect is associated with the down-regulation of the intracellular phospholipase DDHD domain-containing protein 1 (DDHD1). While few studies are currently available on DDHD1 contribution in neurological disorders, information on its involvement in cancer is missing. Here we investigate the role of DDHD1 in colon cancer. Material and methods DDHD1 siRNAs and overexpression vector were transfected into colorectal cancer and normal cells to down-regulate or up-regulate DDHD1 expression. In vitro and in vivo assays were performed to investigate the fun…
Small interfering RNA (siRNA) inhibits the expression of the Her2/neu gene, upregulates HLA class I and induces apoptosis of Her2/neu positive tumor …
2003
Silencing of a specific mRNA using double stranded RNA oligonucleotides represents one of the newest technologies for suppressing a specific gene product. Small interfering RNA (siRNA) are 21 nucleotides long, double stranded RNA fragments that are identical in sequence to the target mRNA. We designed 3 such siRNA against the Her2/neu (HER2) gene. The HER2 gene is known to play an important role in the oncogenesis of several types of cancers, such as breast, ovarian, colon and gastric cancers. Introduction of the siRNA into HER2 positive tumor lines in vitro greatly reduced the cell surface expression of the HER2 protein. Concurrently, a range of effects on cell physiology, such as growth i…
WIN55,212-2-induced expression of Mir-29b1 favours the suppression of osteosarcoma cell migration in a SPARC-independent manner
2019
WIN55,212-2 (WIN) is a synthetic agonist of cannabinoid receptors that displays promising antitumour properties. The aim of this study is to demonstrate that WIN is able to block the migratory ability of osteosarcoma cells and characterize the mechanisms involved. Using wound healing assay and zymography, we showed that WIN affects cell migration and reduces the activity of the metalloproteases MMP2 and MMP9. This effect seemed to be independent of secreted protein acidic and rich in cysteine (SPARC), a matricellular protein involved in tissue remodeling and extracellular matrix deposition. SPARC release was indeed prevented by WIN, and SPARC silencing by RNA interference did not influence …
Differential regulation of apoptosis-associated genes by estrogen receptor alpha in human neuroblastoma cells
2012
Purpose: The neuroendocrinology of female sex hormones is of great interest for a variety of neuropsychiatric disorders. In fact, estrogens and estrogen receptors (ERs) exert neuromodulatory and neuroprotective functions. Here we investigated potential targets of the ER subtype alpha that may mediate neuroprotection and focused on direct modulators and downstream executors of apoptosis. Methods: We employed subclones of human neuroblastoma cells (SK-N-MC) stably transfected with one of the ER subtypes, ERalpha or ERbeta. Differences between the cell lines regarding the mRNA expression levels were examined by qPCR, changes on protein levels were examined by Western Blot and immunocytochemist…