Membrane Depolarization Drives Tumor-Suppressive Cell Competition via Hedgehog Signaling Activation
Tumor-suppressive cell competition (TSCC) is an evolutionarily conserved process that safeguards tissue integrity by selectively eliminating less-fit, precancerous cells. While bioelectric regulation via plasma membrane potential (Vm) is emerging as a key modulator of cellular fitness, its mechanistic role in TSCC remains underexplored. Here, we combine Drosophila genetics, single-cell RNA sequencing (scRNA-seq), and mammalian co-culture models to demonstrate that Vm depolarization acts as a critical driver of TSCC through Hedgehog signaling. In Drosophila eye epithelia, as revealed by performing scRNA-seq, scribble-deficient loser clones exhibit mitochondrial respiratory chain defects, leading to reduced ATP synthesis and subsequent plasma membrane depolarization. The further isolation of unique cell subclusters identify the fluctuations in both winner and loser clones, showing correlations between plasma membrane depolarization and Hh signaling pathway. This depolarization stabilizes Smoothened (Smo) at the membrane, aberrantly activating Hh signaling and triggering the elimination of scribble-deficient clones. Strikingly, this mechanism is conserved in mammalian epithelia. Scrib-depleted Madin-Darby Canine Kidney (MDCK) cells display Vm depolarization-dependent elimination via Hh pathway activation. Together, our work advances the understanding of bioelectricity in cancer surveillance and provides a mechanistic framework for targeting membrane potential in cancer prevention therapies that exploit cell competition.