#Digoxin antidote trial#

After treatment, growth inhibition (relative to DMSO control) was determined by CellTiter-Glo Luminescent assay. H69 cells were treated with DMSO control, digoxin, various doses of NaCl or the combination of digoxin and NaCl for 72 hours. (B) The increased anti-tumor activity of digoxin was dependent on the doses of Na + supplement. H69, H82 and H1963 cells were treated with DMSO control, digoxin (25nM in H69 and H1963, 15nM in H82), NaCl (50mM) or the combination of digoxin and NaCl for 72 hours. (A) Dramatical growth inhibition of SCLC cells induced by co-treatment of digoxin and NaCl. After treatment, PARP and loading control β-actin were detected by western blotting. SCLC cells (H69, H82, H526, H1963 and H196) were treated with DMSO control, 50 nM and 100 nM digoxin for 24 hours. (E) Digoxin induced apoptosis as indicated by PARP cleavage.

The percentage of apoptotic cells (Annexin V positive) was shown in Q2 + Q3. After treatment, Annexin V apoptotic assay was performed by flow cytometry. H69 cells were treated with DMSO control, 50 nM and 100 nM digoxin for 24 hours. (D) Digoxin induced apoptosis as indicated by Annexin V staining. After treatment, flow cytometry was performed. (C) Digoxin induced G 2/M cell cycle arrest. The IC 50 values were determined from the sigmoidal dose–response curves using PRISM5 software. The cell viability was assessed by CellTiter-Glo assay. Various SCLC cell lines were treated with different concentrations (10 −5nM–10μM) of digoxin for 72 hours. (B) Dose-dependent growth inhibition by digoxin in a panel of SCLC cell lines. 1092 FDA-approved drugs were screened and top 20 effective drugs were shown in the heatmap. (A) The heatmap of high-throughput drug screening that discovered that cardiac glycosides (digoxin and ouabain) effectively inhibited the growth of SCLC cells.

#Digoxin antidote trial#

Further, our study suggests that digoxin treatment could need to be combined with NaCl supplement in future clinical trial of SCLC, particularly where low Na + is often present in SCLC patients.ĪTP1A1 NaCl cardiac glycosides digoxin small cell lung cancer. Thus, this is the first demonstration that NaCl is a potent supplement necessitating superior anti-cancer effects of digoxin for SCLC. Lastly, our data revealed that NaCl supplement was able to induce the expression of ATP1A1 (a Na +/K + ATPase subunit), in which contributes directly to the increased sensitivity of SCLC cells to digoxin. We also found that this combination lead to morphological shrinking of SCLC cells, together with high levels of cytochrome C release. Subsequent analysis revealed that this novel combination of digoxin/NaCl caused an up-regulation of intracellular Na + and Ca 2+ levels with an induction of higher resting membrane potential of SCLC cells. Intriguing findings showed that NaCl supplement markedly enhanced the anti-tumor activities of digoxin in both in vitro and in vivo models of SCLC. By screening a FDA-approved drug library, we identified a cardiac glycoside (CG), namely digoxin (an inhibitor of cellular Na +/K + ATPase pump), which was highly effective in inhibiting SCLC cell growth. Effective new therapy for advanced SCLC patients is urgently needed. Small cell lung cancer (SCLC) is a malignant neuroendocrine tumor with very high mortality.