Sodium chloride (NaCl) potentiates digoxin-induced anti-tumor activity in small cell lung cancer

Area of Science:

• Oncology
• Pharmacology
• Biochemistry

Background:

• Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor with high mortality and limited effective therapies.
• There is an urgent need for novel therapeutic strategies for advanced SCLC patients.

Purpose of the Study:

• To identify effective therapeutic agents for SCLC from a library of FDA-approved drugs.
• To investigate the synergistic effect of digoxin and sodium chloride (NaCl) in inhibiting SCLC growth.

Main Methods:

• Screening of an FDA-approved drug library to identify potential SCLC inhibitors.
• In vitro and in vivo studies using SCLC models to evaluate the efficacy of digoxin and NaCl combination.
• Analysis of intracellular ion levels, membrane potential, and cell morphology.
• Investigation of the role of ATP1A1 expression in digoxin sensitivity.

Main Results:

• Digoxin, a cardiac glycoside, demonstrated significant inhibition of SCLC cell growth.
• NaCl supplementation markedly enhanced the anti-tumor activity of digoxin in SCLC models.
• The digoxin/NaCl combination increased intracellular Na+ and Ca2+ levels, elevated resting membrane potential, and induced SCLC cell shrinkage and cytochrome C release.
• NaCl induced ATP1A1 expression, increasing SCLC cell sensitivity to digoxin.

Conclusions:

• NaCl is a potent supplement that enhances the anti-cancer effects of digoxin in SCLC.
• The combination of digoxin and NaCl represents a novel therapeutic approach for SCLC.
• Future clinical trials for SCLC should consider combining digoxin with NaCl supplementation, especially in patients with low sodium levels.