Search results for "expression"
showing 10 items of 5168 documents
miRNAs and their potential for use against cancer and other diseases
2007
miRNAs are 19–24 nucleotide long noncoding RNAs found in almost all genetically dissected species, including viruses, plants, nematodes, flies, fish, mice and humans. Rapid advances have been made in understanding their physiological functions, while abnormal patterns of miRNA expression have been found in many disease states, most notably human cancer. It is now clear that miRNAs represent a class of genes with a great potential for use in diagnosis, prognosis and therapy. In this review we will focus on the discoveries that elucidate their crucial role in mammalian diseases, particularly in cancer, and propose that miRNA-based gene therapy might become the potential technology of choice …
The AC133 epitope, but not the CD133 protein, is lost upon cancer stem cell differentiation.
2010
Abstract Colon cancer stem cells (CSC) can be identified with AC133, an antibody that detects an epitope on CD133. However, recent evidence suggests that expression of CD133 is not restricted to CSCs, but is also expressed on differentiated tumor cells. Intriguingly, we observed that detection of the AC133 epitope on the cell surface decreased upon differentiation of CSC in a manner that correlated with loss of clonogenicity. However, this event did not coincide with a change in CD133 promoter activity, mRNA, splice variant, protein expression, or even cell surface expression of CD133. In contrast, we noted that with CSC differentiation, a change occured in CD133 glycosylation. Thus, AC133 …
Acquired resistance of melanoma cells to the antineoplastic agent fotemustine is caused by reactivation of the DNA repair gene mgmt
2001
Acquired resistance to antineoplastic agents is a frequent obstacle in tumor therapy. Malignant melanoma cells are particularly well known for their unresponsiveness to chemotherapy; only about 30% of tumors exhibit a transient clinical response to treatment. In our study, we investigated the molecular mechanism of acquired resistance of melanoma cells (MeWo) to the chloroethylating drug fotemustine. Determination of O6-methylguanine-DNA methyltransferase (MGMT) activity showed that MeWo cells that acquired resistance to fotemustine upon repeated treatment with the drug display high MGMT activity, whereas the parental cell line had no detectable MGMT. The resistant cell lines exhibit cross-…
Activating mutations in human c-Ha-ras-1 protooncogene induced by stereoisomeric fjord-region benzo[c]chrysene diol-epoxides.
1995
The mutagenicity of fjord-region benzo[c]chrysene diol-epoxide (BcCDE) stereoisomers((+) anti-BcCDE, (-)anti-BcCDE, (+)syn-BcCDE, and (-)syn-BcCDE) was studied in a forward-mutation system. pEC plasmid containing the human c-Ha-ras-1 proto-oncogene was reacted in vitro with each optically active isomer separately and transfected into NIH/3T3 cells. Morphologically transformed foci were cloned, and DNA obtained from these foci was tested for the presence of Ha-ras-1 sequence by Southern blot analysis. A total of 50 transformed foci (11-14 for each diastereomer) were generated. To determine the nature of mutations responsible for activating the proto-oncogene, regions of the gene likely to co…
Allelic loss but absence of mutations in the polyspecific transporter geneBWR1Aon 11p15.5 in hepatoblastoma
2004
Chromosomal region 11p15.5 shows frequent maternal allelic loss in embryonal tumors, including rhabdomyosarcoma (RMS), Wilms' tumor (WT) and hepatoblastoma (HB), consistent with the presence of at least one tumor suppressor gene in this region, which should be paternally imprinted, i.e., expressed from the maternal allele only. The BWR1A gene encodes a polyspecific transmembrane transporter and is located on 11p15.5. It is highly expressed in liver, paternally imprinted and was found to be mutated in an RMS cell line, making it a plausible tumor suppressor gene for HB. We therefore screened 62 HBs, 3 HB cell lines and 1 pediatric hepatocellular carcinoma for BWR1A mutations using single-str…
Stochastic Loss of Silencing of the Imprinted Ndn/NDN Allele, in a Mouse Model and Humans with Prader-Willi Syndrome, Has Functional Consequences
2013
Genomic imprinting is a process that causes genes to be expressed from one allele only according to parental origin, the other allele being silent. Diseases can arise when the normally active alleles are not expressed. In this context, low level of expression of the normally silent alleles has been considered as genetic noise although such expression has never been further studied. Prader-Willi Syndrome (PWS) is a neurodevelopmental disease involving imprinted genes, including NDN, which are only expressed from the paternally inherited allele, with the maternally inherited allele silent. We present the first in-depth study of the low expression of a normally silent imprinted allele, in path…
Presence of the Transmembrane Protein Neuropilin in Cytokine-induced Killer Cells
2020
Background/aim Cytokine-induced killer (CIK) cells are a heterogenous population of immune cells showing promising applications in immunotherapeutic cancer treatment. Neuropilin (NRP) proteins have been proven to play an important role in cancer development and prognosis. In this study, CIK cells were tested for expression of NRPs, transmembrane proteins playing a role in the proliferation and survival of cancer cells. Materials and methods CIK cells were analyzed at different time points via flow cytometry and quantitative real-time polymerase chain reaction for neuropilin expression. Results Phenotyping results showed CIK cells having developed properly, and low levels of NRP2 were detect…
MiRNA profiling by NGS in resectable non-small cell lung cancer: Prognostic implications.
2014
7559 Background: MicroRNAs (miRNA) regulate gene expression, and are implicated in several processes like tumorogenesis. Here, we applied a multiplexed NGS approach to study differentially expressed miRNAs (tumor/ normal) in a cohort of resectable NSCLC patients and its correlation with clinical outcome. Methods: RNA was isolated from frozen lung specimens (tumor/ normal) from 33 patients. High-quality samples were analyzed and enriched in the miRNA fraction. Libraries were prepared according to manufactured instruction (SOLID), and miRNAs were sequenced. Data analysis was carried out using CLCbio software. First, raw data were annotated using miRBase and normalized by total reads followed …
miR-155expression in antitumor immunity: The higher the better?
2019
MicroRNAs are small noncoding RNAs that modulate gene expression either directly, by impairing the stability and/or translation of transcripts that contain their specific target sequence, or indirectly through the targeting of transcripts that encode transcription factors, factors implicated in signal transduction pathways, or epigenetic regulators. Abnormal expression of micro-RNAs has been found in nearly all types of pathologies, including cancers. MiR-155 has been the first microRNA to be implicated in the regulation of the innate and adaptative immune responses, and its expression is either increased or decreased in a variety of liquid and solid malignancies. In this review, we examine…
Antitumor effect of B16 melanoma cells genetically modified with the angiogenesis inhibitor rnasin.
2001
The growth of new blood vessels is an essential condition for the development of tumors with a diameter greater than 1-2 mm and also for their metastatic dissemination. RNasin, the placental ribonuclease inhibitor, is known to have antiangiogenic activity through the inhibition of angiogenin and basic fibroblast growth factor. Nevertheless, the administration of the recombinant form of a protein poses several limitations; as a result, we have studied the antitumor effect of RNasin in a murine gene therapy model. RNasin cDNA was subcloned into the pcDNA3 expression vector, and the resulting recombinant plasmid was used to transfect the B16 murine melanoma cell line. An RNasin inverted constr…