Selective elimination of pluripotent stem cells by PIKfyve specific inhibitors

Area of Science:

• Cell Biology
• Cancer Research
• Stem Cell Biology

Background:

• PIKfyve phosphoinositide kinase regulates lysosome homeostasis and is crucial for autophagy-dependent cancer cell survival.
• Pluripotent stem cells, including embryonal carcinoma cells (ECCs), embryonic stem cells, and induced pluripotent stem cells, possess unique vulnerabilities.
• Targeting specific cellular pathways offers a strategy for selective cancer therapy.

Purpose of the Study:

• To investigate the selective elimination of pluripotent stem cells by PIKfyve inhibitors.
• To determine the mechanism by which PIKfyve inhibition affects pluripotent versus differentiated cells.
• To evaluate the in vivo efficacy of PIKfyve inhibitors in eliminating pluripotent cancer cells.

Main Methods:

• Treatment of pluripotent and differentiated cells with PIKfyve inhibitors.
• Analysis of lysosome fission, autophagosome accumulation, and cell proliferation.
• Xenograft studies using ECC-derived teratocarcinomas and PIKfyve inhibitor WX8 in mice.

Main Results:

• PIKfyve inhibitors selectively induced death in pluripotent cells while sparing differentiated cells.
• Inhibition of PIKfyve prevented lysosome fission and increased autophagosome accumulation in both cell types.
• In vivo studies demonstrated that WX8 selectively eliminated pluripotent ECCs in teratocarcinoma xenografts.
• Differentiated cells exhibited reduced proliferation but not death upon PIKfyve inhibition.

Conclusions:

• PIKfyve inhibitors exhibit selective toxicity towards pluripotent stem cells, including cancer stem cells.
• Disruption of lysosome homeostasis by PIKfyve inhibition is the key mechanism for selective cell death.
• PIKfyve inhibitors represent a potential therapeutic strategy for targeting and eliminating pluripotent cancer cells in vitro and in vivo.