Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:5.99.1.2 (topoisomerase)
 9,166 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the formation of linked circular DNA molecules promoted by the combined action of rec 1 protein and type I topoisomerase of Ustilago maydis. When ATP was added as cofactor to reactions containing rec 1 protein, pairs of homologous circular DNA molecules became linked after addition of topoisomerase. Closed circular duplex molecules could be joined at homologous sites with circular single-stranded molecules or with other circular duplex molecules, provided that homologous single-stranded DNA fragments or RNA polymerase and nucleoside triphosphates were also added. Complexes formed were topologically linked through regions of heteroduplex DNA. When the analog adenylyl-imidodiphosphate was substituted for ATP, nonhomologous pairs of circular DNA molecules became linked.
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PMID:Topological linkage of circular DNA molecules promoted by Ustilago rec 1 protein and topoisomerase. 631 15

Etoposide is a podophyllotoxin semiderivative that is used in a variety of chemotherapy treatments, including therapy for children tumors. This drug promotes the formation of a ternary DNA-topoisomerase II-etoposide complex that triggers apoptosis. The purpose of this work was to analyze the occurrence of apoptosis in the seminiferous epithelium of prepubertal, pubertal, and adult rats treated with 10, 20, and 40 mg/Kg of etoposide during the prepubertal phase, as well as the role of apoptosis in etoposide-induced testicular damage. The rat testes were fixed in Bouin's liquid, and the apoptotic cells were quantified by means of the hematoxylin and eosin (H&E) technique (all groups) and the terminal dUTP nick end labeling (TUNEL) method (prepubertal groups only). The results obtained from both the H&E and TUNEL methods showed an increased frequency of apoptosis in the seminiferous epithelium of treated animals, except for the subgroup that received the 10-mg/Kg dose and was sacrificed 12 hr after the treatment and for the etoposide-treated pubertal group, that did not show cells suggesting apoptosis during H&E analysis. The labeled cells were mainly primary spermatocytes and differentiated spermatogonia. The prepubertal rats showed an etoposide-dose-dependent diminution of differentiated spermatogonia. Etoposide treatment during the prepubertal phase increases the frequency of apoptosis in the seminiferous epithelium, and causes serious harm to male fertility. 2004.
Anat Rec A Discov Mol Cell Evol Biol 2004 Jul
PMID:Apoptosis and testicular alterations in albino rats treated with etoposide during the prepubertal phase. 1522 3

We have presented a structural model of the chromosome based on its constituent proteins. Development of a method of mass isolation for intact human metaphase chromosomes and proteome analysis by mass spectrometry of the isolated chromosomal proteins enabled us to develop a four-layer structural model of human metaphase chromosomes. The model consists of four layers, each with different chromosomal protein sets, i.e., chromosome coating proteins (CCPs), chromosome peripheral proteins (CPPs), chromosome structural proteins (CSPs), and chromosome fibrous proteins (CFPs). More than 200 identified proteins have been classified and assigned to the four layers with each layer occupying a distinct region of the chromosome. CCPs are localized at the most outer regions of the chromosomes and they attach to the regions tentatively and occasionally. CCPs include mostly mitochondrial and cytoplasmic proteins, e.g., 70 kDa heat shock protein 9B and Hsp60. CPPs are also localized at the peripheral regions of the chromosomes, but as the essential part of the chromosomes. CPPs include nucleolin, lamin A/C, fibrillarin, etc. CSPs are the primary chromosomal structure proteins, and include topoisomerase IIalpha, condensin subunits, histones, etc. CFPs have a fibrous nature, e.g., beta-actin, vimentin, myosin II, tublin, etc. A data set of these proteins, which we developed, contains essential chromosome proteins with classified information based on this four-layer model and presents useful leads for further studies on chromosomal structure and function.
Chem Rec 2007
PMID:Chromosome protein framework from proteome analysis of isolated human metaphase chromosomes. 1766 45

Metastasis and multidrug resistance (MDR) are the main reasons for the poor prognosis of non-small cell lung cancer (NSCLC) patients. The use of biomarkers may contribute to a more accurate prediction of tumor metastasis, a better response to chemotherapy, and better patient survival. Gelsolin-like actin-capping protein (CapG) and gelsolin have been identified as playing important roles in tumor invasion and metastasis. Permeability glycoprotein (P-gp), glutathione S-transferase pi (GSTP1), and topoisomerase-II (Topo-II) are proteins that are closely related to MDR. In this study, we assessed the prognostic significance of CapG and gelsolin (both markers of tumor motility), and of P-gp, GSTP1, and Topo-II (markers of MDR) in NSCLC patients. One hundred and twenty-one patients with pathologically confirmed, resectable NSCLC were included in the study. The expression levels of the five kinds of proteins mentioned above were determined by immunohistochemistry (IHC). The correlation between the clinical characteristics and IHC findings were analyzed. Expression of CapG, gelsolin, and P-gp was found to be associated with an increased risk of death (Hazard Ratio (HR) = 2.799, 95% Confidence Interval (CI) = 1.2705-6.169, P = 0.011; HR = 3.968, 95% CI = 1.811-8.693, P = 0.001; HR = 3.251, 95% CI = 1.456-7.260, P = 0.004, respectively), whereas expression of GSTP1 and Topo-II was not. These results suggest that higher tumor motility and MDR may be important in NSCLC prognosis.
Anat Rec (Hoboken) 2012 Feb
PMID:Prognostic evaluation of CapG, gelsolin, P-gp, GSTP1, and Topo-II proteins in non-small cell lung cancer. 2219 May 10

The use of the element boron, which is not generally observed in a living body, possesses a high potential for the discovery of new biological activity in pharmaceutical drug design. In this account, we describe our recent developments in boron-based drug design, including boronic acid containing protein tyrosine kinase inhibitors, proteasome inhibitors, and tubulin polymerization inhibitors, and ortho-carborane-containing proteasome activators, hypoxia-inducible factor 1 inhibitors, and topoisomerase inhibitors. Furthermore, we applied a closo-dodecaborate as a water-soluble moiety as well as a boron-10 source for the design of boron carriers in boron neutron capture therapy, such as boronated porphyrins and boron lipids for a liposomal boron delivery system.
Chem Rec 2015 Jun
PMID:Boron-Based Drug Design. 2580 Jun 54