PubMed · 12238758
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
K Rudi, J Treimo, B Moen, I Rud, G Vegarud. 2002. Internal controls for normalizing DNA arrays.. https://doi.org/10.2144/02333bm07
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Although progress in clinical and basic research has significantly increased our understanding of breast cancer, little is known about the molecular mechanism underlying breast cancer metastasis. Identification of effective therapeutic targets to prevent breast cancer metastasis is urgently needed. The function of miR-503-3p has been investigated in other cancers, but its role in breast cancer remains undefined. Here, we found that miR-503-3p was overexpressed in breast cancer tissue and plasma compared with adjacent normal breast tissue and with plasma from healthy individuals. Moreover, we identified miR-503-3p to be an oncogene of breast cancer cell proliferation, migration and invasion. Upregulation of miR-503-3p in breast cancer cells inhibited expression of epithelial-mesenchymal transition (EMT)-related protein SMAD2 and the epithelial marker protein E-cadherin by directly binding to their mRNA 3' untranslated region, whereas increased expression of mesenchymal marker proteins, including vimentin and N-cadherin. Taken together, our findings support a critical role for miR-503-3p in induction of breast cancer EMT and suggest that plasma miR-503-3p may be a useful diagnostic biomarker for breast cancer.
Isolation of single cells permits analysis of DNA or RNA from individual cells among heterogeneous populations. This technique is particularly useful in the study of classical Hodgkin's lymphoma (cHL) due to the scarcity of H/RS tumor cells among large numbers of reactive leukocytes. In a previous study, we found a high frequency of dual LMP-1 variant (concurrent presence of deleted and nondeleted variants) in cHL from whole-tissue sections. For the present study, we applied a single-cell isolation technique to determine the LMP-1 oncogene variant in EBV-associated H/RS cells. Five cases of EBV-infected cHL, containing nondeleted (n=1), deleted (n=1) and dual infection (n=3) based on whole-tissue section analysis, were selected for study. Paraffin-embedded tissue sections were stained with antibody to LMP-1 and positively stained H/RS cells isolated using a semiautomated micromanipulator. Each isolated single cell was subjected to PCR for amplification of the LMP-1 gene flanking the 30 bp deletion region and Xho1 restriction site. Cases with either nondeleted variant or the deleted variant showed similar LMP-1 variant expression in isolated single H/RS cells. However, 1 of the 3 cases with dual variants showed only the deleted variant in H/RS cells. The other 2 cases showed mixed patterns of deleted, nondeleted and dual LMP-1 variants in isolated single H/RS cells. All cases showed loss of the Xho1 restriction site, with the exception of the case with nondeleted LMP-1. Results of single-H/RS cell analysis of the Xho1 restriction site concur with those of whole-tissue section amplification. A mixed pattern of LMP-1 variants was observed in isolated H/RS cells, and it is speculated that this is due to the accumulation of mutation and deletion events.
Several second-generation inhibitors of DNA (cytosine-5) methyltransferases based on studies of modified synthetic oligodeoxynucleoides have been described. As an aid to studies of these inhibitors, we present an electronic structure-based algorithm that can be used as a method for predicting the nature of the expected inhibition by any noncytosine nucleotide target. Targeting by the major human enzyme (hDnmt1) is governed by the presence of a three-nucleotide motif. In hemimethylated DNA, this motif consists of a 5-methylcytosine targeting signal that causes the enzyme to probe the opposite strand for a normally paired guanosine or inosine residue and attempt to methylate the residue 5' to that site. As a demonstration of the method, we apply these rules to the design and characterization of a novel oligodeoxynucleotide inhibitor of hDnmt1. This inhibitor takes advantage of the three-nucleotide recognition motif characteristic of hDnmt1 and shows that the enzyme is inhibited in vitro by non-CG methylation which targets the enzyme to normally basepaired but unproductive nucleotides such as dG, dA, and dT. Kinetic analysis at constant S-adenosyl-L-methionine concentration shows that representative inhibitory oligodeoxynucleotides are best viewed as weakly productive components of systems containing two DNA substrates. This model suggests that the most effective inhibitors are those with very low apparent Vmax and very low Km values. Oligodeoxynucleotides containing mispaired and unproductive targets such as dG, dA, dT, and dU are also inhibitory as secondary substrates for the human enzyme. Biologically, fail-safe mechanisms identified by the ab initio approach appear to be active in preventing potentially mutagenic deamination of dihydrocytosine and enzymatic methylation of dU.