High grade serous ovarian cancer (HGSC) initially responds to platinum-based chemotherapy, but recurrent disease with chemotherapy resistance remains a major clinical problem. A subpopulation of tumor cells with stem-like properties, termed ovarian cancer stem cells (OCSCs), are implicated in therapeutic failure because they survive treatment and can repopulate tumors. The study summarized here examined whether platinum treatment enriches OCSCs solely by selecting pre-existing resistant cells or also by inducing cellular plasticity that generates new OCSC-like cells.
Using cisplatin as a representative platinum agent, investigators observed not only enrichment of existing OCSCs but also a conversion of ALDH- cells into ALDH+ cells after treatment. ALDH positivity is used here as a marker of OCSC-like phenotype. This finding supports a model in which chemotherapy can promote acquisition of stem-like features in previously non-stem tumor cells, i.e., chemotherapy-induced plasticity, contributing to overall expansion of the OCSC pool.
Molecular profiling associated the cisplatin-induced conversion with changes in nuclear receptor signaling pathways. Two ligand-dependent nuclear receptor heterodimer pathways were highlighted: vitamin D receptor/retinoid X receptor (VDR/RXR) signaling and retinoic acid receptor/retinoid X receptor (RAR/RXR) signaling. The data indicate these nuclear receptor pathways are associated with the shift toward an ALDH+ phenotype after platinum exposure, suggesting a regulatory link between ligand-activated nuclear receptors and OCSC plasticity.
Activation of VDR/RXR signaling using vitamin D reduced markers and behaviors associated with stemness and suppressed the cisplatin-induced conversion of ALDH- cells to ALDH+ cells in the experimental systems reported. This result identifies VDR/RXR activation as a negative regulator of chemotherapy-induced acquisition of stem-like properties and positions vitamin D signaling as a potential modulator of OCSC plasticity.
In animal models reported by the authors, combining vitamin D with cisplatin decreased tumor volume more than either intervention alone, indicating a potential therapeutic benefit from co-targeting VDR/RXR during platinum chemotherapy. The source abstract reports this in vivo effect but does not provide detailed experimental parameters, such as dosing, treatment schedule, or sample size, in the abstract text. Those details and statistical analyses are available in the full preprint and supplementary materials referenced in the source.
Collectively, the findings suggest platinum chemotherapy can actively promote the acquisition of stem-like properties in ovarian cancer cells, not only selecting for pre-existing OCSCs. The identification of VDR/RXR signaling as a pathway that, when activated by vitamin D, reduces stemness phenotypes and cisplatin-induced conversion offers a candidate strategy to limit OCSC-driven relapse and improve platinum responses.
However, the report is a preprint and has not been peer reviewed. The abstract summarizes key observations but does not include full experimental details, such as methods, sample sizes, quantitative outcomes, or potential toxicities of combined therapy. The authors also report that cisplatin increased RAR/RXR signaling, which may have an opposing or complex role in OCSC plasticity; the abstract does not elaborate on functional studies targeting RAR/RXR. For clinical translation, additional peer-reviewed validation, mechanistic dissection, and evaluation of safety and dosing will be necessary.
This preclinical study supports a model in which platinum chemotherapy can induce cellular plasticity that expands the OCSC population via nuclear receptor–linked pathways. Activation of VDR/RXR signaling with vitamin D attenuated cisplatin-driven conversion to ALDH+ OCSC-like cells and improved tumor control in vivo when combined with cisplatin, suggesting vitamin D–based modulation of this pathway could be explored as an adjunct to platinum chemotherapy. Readers should consult the full preprint for detailed methods, data, and limitations; the study has not yet undergone peer review.