Hemophilia Awards system (Bayer). R.A.G. is supported by a grant under the Females Scientists Programme in the Department of Science and Technology (New Delhi, India). G.S. is supported by a Ph.D. student fellowship from the DBT (New Delhi, India). N.S. acknowledges the assistance in the DBT, Government of India. Author Disclosure Statement No competing economic interests exist.
Pallis et al. BMC Pharmacology and Toxicology 2013, 14:32 http://www.biomedcentral/2050-6511/14/RESEARCH ARTICLEOpen AccessEfficacy of RNA polymerase II inhibitors in targeting dormant leukaemia cellsMonica Pallis1,4*, Francis Burrows2, Abigail Whittall3, Nicholas Boddy3, Claire Seedhouse3 and Nigel Russell1,AbstractBackground: Dormant cells are characterised by low RNA synthesis. In contrast, cancer cells is usually addicted to high RNA synthesis, like synthesis of survival molecules. We hypothesised that dormant cancer cells, already low in RNA, may be sensitive to apoptosis induced by RNA Polymerase II (RP2) inhibitors that further decrease RNA synthesis. Methods: We cultured leukaemia cells continuously in vitro within the presence of an mTOR inhibitor to model dormancy. Apoptosis, harm, RNA content and decreasing capacity had been evaluated. We treated dormancy-enriched cells for 48 hours together with the nucleoside analogues ara-C, 5-azacytidine and clofarabine, the topoisomerase targeting agents daunorubicin, etoposide and irinotecan and three multikinase inhibitors with activity against RP2 flavopiridol, roscovitine and TG02, and we measured development inhibition and apoptosis.FC-11 Description We describe use of your parameter two IC50 to measure residual cell targeting.Hepcidin-25 (human) Metabolic Enzyme/Protease RNA synthesis was measured with 5-ethynyl uridine. Druginduced apoptosis was measured flow cytometrically in main cells from individuals with acute myeloid leukaemia making use of a CD34/CD71/annexinV gating tactic to identify dormant apoptotic cells. Results: Culture in the KG1a cell line continuously in the presence of an mTOR inhibitor induced functions of dormancy which includes low RNA content material, low metabolism and low basal ROS formation in the absence of a DNA harm response or apoptosis. All agents were extra helpful against the unmanipulated than the dormancyenriched cells, emphasising the chemoresistant nature of dormant cells. However, the percentage of cell reduction by RP2 inhibitors at 2 IC50 was considerably greater than that of other agents.PMID:23415682 RP2 inhibitors strongly inhibited RNA synthesis compared with other drugs. We also showed that RP2 inhibitors induce apoptosis in proliferating and dormancy-enriched KG1a cells and within the CD71neg CD34pos subset of primary acute myeloid leukaemia cells. Conclusion: We recommend that RP2 inhibitors may well be a useful class of agent for targeting dormant leukaemia cells. Keyword phrases: Leukemia, Dormancy, RNA polymerase II inhibitorsBackground Relapse in cancer individuals immediately after therapy is on account of the continued presence of a subset of cells which can be most likely to possess evaded the effects of treatment by lying dormant [1,2]. Dormant cells are characterised by low levels of RNA, consistent with their lack of proliferation and ought to conserve power [3]. Even so, cancer cells may well be dependent on (“addicted to”) survival gene expression [4,5] and thus be primed for death if the survival genes are down-regulated [6]. Therefore we hypothesised that* Correspondence: [email protected] 1 Nottingham University Hospitals, Nottingham, UK 4 Academic Haematology, Clinical Sciences Developing, Nottingham Universi.