Missense mutation of
tumor suppressor p53, which exhibits oncogenic gain-of-function (GOF), not only promotes
tumor progression, but also diminishes therapeutic efficacies of
cancer treatments. However, it remains unclear how a p53 missense mutant contributes to induced pluripotency of cancer stem cells (CSCs) in
tumors exposed to chemotherapeutic agents. More importantly, it may be possible to abrogate the GOF by restoring wild-type p53 activity, thereby overcoming the deleterious effects resulting from heterotetramer formation, which often compromises the efficacies of current approaches being used to reactivate p53 function. Herewith, we report that p53 R273H missense mutant urges
cancer cells to spawn CSCs. SW48/TP53 cells, which heterozygously carry the p53 R273H hot-spot mutant (R273H/+, introduced by a CRISPR/Casp9 system), were subchronically exposed to
doxorubicin in cell culture and in
tumor-bearing mice. We found that p53-R273H (TP53-Dox) cells were
drug-resistant and exhibited epithelial-mesenchymal transition (EMT) and increased numbers of CSCs (CD44v6+/CD133+), which resulted in enhanced wound healing and
tumor formation. Inhibition of
glucosylceramide synthase with
d-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (
PDMP) sensitized p53-R273H
cancer cells and
tumor xenografts to
doxorubicin treatments. Intriguingly,
PDMP treatments restored wild-type p53 expression in heterozygous R273H mutant cells and in
tumors, decreasing CSCs and sensitizing cells and
tumors to treatments. This study demonstrated that p53-R273H promotes EMT and induced pluripotency of CSCs in
cancer cells exposed to
doxorubicin, mainly through Zeb1 and β-
catenin transcription factors. Our results further indicate that restoration of p53 through inhibition of
ceramide glycosylation might be an effective treatment approach for targeting
cancers heterozygously harboring TP53 missense mutations.