Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Camptothecin (CPT), a specific topoisomerase I inhibitor, in the presence of hematopoietic growth factors exerted an antiproliferative effect against normal bone marrow cells (NBMC) as well as chronic myelogenous leukemia-chronic phase (CML-CP) and blast crisis (CML-BC) cells. In the absence of growth factors, however, only the colony formation by CML-BC cells was inhibited by CPT, leaving NBMC and CML-CP cells intact or much less affected. Analysis of the cellular DNA content revealed that CPT induced specific changes in cell cycle distribution: decrease in S and G2/M fraction with simultaneous accumulation of the cells in G1 phase and the appearance of "sub-diploid" (apoptotic) peak. To determine if CPT is able to exert selective antileukemic effect, 1:1 mixture of NBMC and CML-BC cells was exposed to CPT in the absence of growth factors and assayed for growth ability in clonogenic assay and for expression of BCR/ABL transcript in single colonies. BCR/ABL transcript was not detected in colonies incubated with CTP, in contrast, most of colonies arising from untreated cells possessed leukemic origin (BCR/ABL expression). Our results indicate that CPT is selectively effective in vitro against the leukemia cells. This offers the prospect of a novel and more selective treatment of CML.
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PMID:The diverse effect of topoisomerase I specific inhibitor (camptothecin) on normal and BCR/ABL-dependent hematopoietic cells proliferation: therapeutic implications. 861 72

Camptothecin (CPT) is a potent inhibitor of DNA topoisomerase I with a wide spectrum of anti-tumor activity. Relatively little information is available regarding the relation of known topoisomerase-mediated DNA damage with other intracellular pathways. To gain an insight into the intracellular molecular mechanisms of Topoisomerase I inhibitor camptothecin-mediated DNA damage leading to cell death, we used a high-density cDNA microarray to assess sensitive early gene expression profiles in SGC7901 (gastric cancer), Hela (cervical adenocarcinoma), K562 (chronic myelogenous leukemia) and HL60 (promyelocytic leukemia) tumor cells stimulated with camptothecin for 1 h at the concentrations of GI50 (50 % growth inhibition after 24 h of treatment). Analysis of the differentially expressed genes obtained 29 response genes common to all four cell lines. Moreover, these cell lines also shared the direction of regulation. Most of these common response genes were functionally related to cell proliferation or apoptosis, and some of them were involved in ATM (ataxia-telangiectasia mutated) and ATR (ATM-and Rad3 related) checkpoint pathways, JNK (c-Jun N-terminal kinase) pathway, the survival phosphatidylinositol (PI) 3 kinase-Akt-dependent pathway, mitochondrial cell death pathway, endoplasmic reticulum (ER)-related cell death pathway, and to ubiquitin/proteasome dependent protein degradation pathway. The data provides evidence for a linkage between topoisomerase-mediated DNA damage and intracellular signaling events, which may facilitate our understanding of the camptothecin mediated molecular mechanisms of action.
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PMID:Analysis of common gene expression patterns in four human tumor cell lines exposed to camptothecin using cDNA microarray: identification of topoisomerase-mediated DNA damage response pathways. 1636 68