Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.5.1.47 (cysteine synthase)
 625 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In addition to their well-known anti-malarial activity, artemisinin and its derivatives (1,2,4-trioxanes) possess potent activity against tumor cells in the nano- to micromolar range. Candidate genes that may contribute to the sensitivity and resistance of tumor cells to artemisinins were identified by pharmacogenomic and molecular pharmacological approaches. Target validation was performed using cell lines transfected with candidate genes or corresponding knockout cells. These genes are from classes with different biological function; for example, regulation of proliferation (BUB3, cyclins, CDC25A), angiogenesis (vascular endothelial growth factor and its receptor, matrix metalloproteinase-9, angiostatin, thrombospondin-1) or apoptosis (BCL-2, BAX). Artesunate triggers apoptosis both by p53-dependent and -independent pathways. Anti-oxidant stress genes (thioredoxin, catalase, gamma-glutamyl-cysteine synthetase, glutathione S-transferases) as well as the epidermal growth factor receptor confer resistance to artesunate. Cell lines over-expressing genes that confer resistance to established anti-tumor drugs (MDR1, MRP1, BCRP, dihydrofolate reductase, ribonucleotide reductase) were not cross-resistant to artesunate, indicating that this drug has a different target and is not subject to multidrug resistance. The Plasmodium translationally controlled tumor protein (TCTP) represents a known target protein of artemisinin and its derivatives in the malaria parasite. The microarray-based mRNA expression of human TCTP correlated with sensitivity to artesunate in tumor cells, suggesting that human TCTP contributes to response of tumor cells to the drug. The multi-factorial nature of cellular response to artemisinin and its derivatives may be beneficial to treat otherwise drug-resistant tumors and may explain why resistance development has not been observed in either cancer or malaria.
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PMID:Mechanistic perspectives for 1,2,4-trioxanes in anti-cancer therapy. 1587 3

It is important to clarify the molecular characteristics of tumor cells showing multidrug resistance (MDR) and to identify the novel targets or biomarkers for chemotherapy. The aim of this study is to establish resistant HeLa sublines through exposure to SN-38, an active metabolite of irinotecan hydrochloride, and to investigate their molecular changes. HeLa cells were exposed to SN-38 at 1, 10, or 100 nM, and resistant clones were isolated and named HeLa/SN1, HeLa/SN10, and HeLa/SN100, respectively. Their cellular changes were examined based on growth inhibition assays, the function of ABCG2/BCRP, and a RT-PCR analysis of MDR-related protein. The sublines showed a decrease in sensitivity to not only SN-38 but also other chemotherapeutic agents as compared with HeLa cells. mRNA and protein levels of ABCG2/BCRP were increased, and the transport activity of ABCG2/BCRP was enhanced, in the resistant cells. In addition, the expression levels of ABCC1/MRP1, ABCC3/MRP3, and ABCC5/MRP5 were higher than in HeLa cells. The mRNA levels of GGT1 encoding a gamma-glutamyl transferase, but not GCS encoding a gamma-glutamyl cysteine synthetase, were also higher. Other factors examined, i.e., topoisomerase, SLCO1B1, and apoptosis-regulating factors, were comparable among the cells. The overexpression of ABCG2/BCRP was involved in the mechanism of resistance in SN-38-tolerant cells, and ABCC1/MRP1, ABCC3/MRP3, ABCC5/MRP5, and GGT1 may also have participated.
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PMID:Molecular changes to HeLa cells on continuous exposure to SN-38, an active metabolite of irinotecan hydrochloride. 1920 Oct 79