Key result
Low-dose doxorubicin reduces hiPSC cell area ~43% while upregulating pluripotency markers.
Effect estimate: 1.75-fold reduction
Absolute Event Rate: 80.96% vs 141.63%
p-value: p=3.2e-46
Low-dose doxorubicin induces a stable reduction in hiPSC size while upregulating pluripotency markers, suggesting an adaptive response that maintains self-renewal under chemotherapeutic stress.
Chemotherapeutic agents can disrupt stem cell pluripotency and self-renewal, yet how hiPSCs adapt to such stress remains unclear. Doxorubicin (Dox), a widely used cancer drug, is known for its cytotoxic effects at high doses; however, its impact at low doses on hiPSC proliferation and self-renewal remains poorly characterized. We hypothesize that low-dose Dox induces an adaptive response in hiPSCs, reducing cell size while preserving pluripotency and self-renewal. JHU001 hiPSCs were treated with 50 nM Dox for 2 hours (hiPSC-D50) and compared to vehicle-treated controls (hiPSC-D0). Both hiPSC-D50 and -D0 were cultured in E8 flex medium, passaged five times, and cryopreserved. Passage 5 was selected to assess stable adaptation following Dox withdrawal. To quantify cell area changes, a total of 161 (hiPSC-D50) and 140 (hiPSCS-D0) individual cells were manually segmented (n= 6) from phase-contrast images using ImageJ. hiPSC-D50 and -D0 cells were examined for pluripotent gene expression (Oct-4, Nanog, and SSEA-4) by immunocytochemistry using epifluorescence microscopy. hiPSC-D50 cells exhibited a significantly smaller mean area (80.96 ± 1.54 micrometer square) compared to hiPSC-D0 cells (141.63 ± 3.36 micrometer square), corresponding to a 1.75-fold reduction (p= 3.2e-46). These findings suggest that low-dose Dox induces a stable reduction in hiPSC size, supporting an adaptive Dox response. Furthermore, immunocytochemistry analysis revealed an upregulation of pluripotency markers, with a 1.3-fold (Oct4), 1.9-fold (Nanog), and 2.9-fold (SSEA-4) increase in hiPSC-D50 relative to -D0 (p= 0.00057, 0.018, 0.0000026, respectively). These results indicate that low-dose Dox reprograms the size threshold, allowing hiPSCs to maintain self-renewal at a reduced size. This aligns with the Sizer model, which states that cells must reach a critical size before division. Furthermore, sustained self-renewal despite size constraints suggests that cell cycle regulators accumulate rapidly, supporting the Accumulating Activator model, where a size-dependent activator triggers mitotic entry at a reduced size. Understanding the molecular mechanisms of size-dependent pluripotency and self-renewal may provide insights into optimizing hiPSC survival and regenerative therapies under chemotherapeutic stress, potentially informing strategies to mitigate toxicity in cancer patients.
No takes yet. Share an insight, caveat, or question.
Joshi‐Mukherjee et al. (2025) studied hiPSC adaptation to chemotherapeutic stress (n=301). Doxorubicin vs. vehicle-treated controls was evaluated on mean cell area (1.75-fold reduction, p=3.2e-46). Low-dose doxorubicin induced a stable 1.75-fold reduction in hiPSC mean cell area (80.96 vs 141.63 square micrometers; p=3.2e-46) while upregulating pluripotency markers.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: