Padilla, J. L. | Search bioRxiv

bioRxiv2025

Curcumin Analogues Trigger HMOX1-Mediated Ferroptosis to Halt Endometrial Cancer Growth

BackgroundAdvanced endometrial cancer remains challenging to treat due to limited therapeutic options and drug resistance. Ferroptosis, an iron-dependent form of cell death, offers a potential strategy for overcoming resistance. Curcumin analogues with improved bioavailability, such as HO-3867 and AKT-100, exhibit potent anti-cancer activity, but their mechanisms remain under-explored. MethodsKLE, Hec50co and Ishikawa endometrial cancer cells were treated with HO-3867 or AKT-100. RNA sequencing, qPCR, and immunoblotting assessed ferroptosis-related gene expression, focusing on HMOX1. Intracellular iron and ROS were measured via FerroOrange and DCFH-DA staining. Cytotoxicity and colony formation were evaluated using CyQUANT assays, with pharmacological inhibitors (ZnPP, Liproxstatin-1, Z-VAD-FMK) and HMOX1 siRNA to dissect the roles of ferroptosis and apoptosis. ResultsBoth analogues upregulated multiple ferroptosis genes, prominently HMOX1. AKT-100 increased intracellular iron and ROS levels. Inhibition of HMOX1, ferroptosis, or apoptosis partially rescued cell viability, while HMOX1 knockdown enhanced clonogenic growth, confirming its key role in AKT-100-mediated cytotoxicity. ConclusionsHO-3867 and AKT-100 induce HMOX1-mediated ferroptosis and apoptosis, effectively suppressing endometrial cancer cell growth. These findings support the therapeutic potential of curcumin analogues and provide a foundation for in vivo studies targeting HMOX1 in endometrial cancer. O_FIG O_LINKSMALLFIG WIDTH=187 HEIGHT=200 SRC="FIGDIR/small/689080v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@610bcorg.highwire.dtl.DTLVardef@34d8eaorg.highwire.dtl.DTLVardef@18d2a5aorg.highwire.dtl.DTLVardef@d7b4f3_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2025

The novel curcumin analogue AKT-100 targets mutant p53 in gynecologic cancer cells

Loss of normal p53 tumor-suppressive activity is common in advanced cancers, where TP53 mutations produce either p53-null states or highly expressed missense proteins with gain of oncogenic function. Mutant p53 proteins not only lose wild type p53 pro-apoptotic and DNA repair functions but also acquire new activities, including constitutive STAT3 activation. We hypothesize that directly targeting missense mutant p53 instead of downstream pathways is advantageous. Curcumin analogues have been reported to bind mutant p53, motivating the development of AKT-100, a novel analogue designed to restore wild type p53 functionality. AKT-100 binds mutant p53 and STAT3, as shown by fluorescence quenching, and inhibits STAT3 Tyr705 phosphorylation in KLE and COV362 cells. This agent exhibits potent cytotoxicity in gynecological cancer cells with IC50 values ranging from 4 nm to 2.51 {micro}M, and demonstrates synergy with the PARP inhibitor olaparib and with chemotherapy by suppressing alternative DNA repair mechanisms associated with therapeutic resistance. RNA sequencing and immunoblotting confirms AKT-100 reactivates wild type p53 transcriptional profiles regulating cell cycle arrest (CDKN1A/p21, GADD45A), apoptosis (PMAIP1/Noxa, DR5), and inhibits DNA replication and repair. These findings support AKT-100 as a promising therapeutic agent with the dual capabilities of directly targeting oncogenic mutant p53 and constitutively active STAT3. HighlightsO_LIAKT-100 is a novel curcumin analogue that functions as a WT p53 reactivator. C_LIO_LIAKT-100 inhibits STAT3 phosphorylation at Tyrosine 705 in endometrial and ovarian cancer cells. C_LIO_LICell proliferation is inhibited in multiple ovarian and serous endometrial cancer cell lines with AKT-100 as a single agent. C_LIO_LIAKT-100 is synergistic with PARP inhibitor olaparib and chemotherapy drugs carboplatin and paclitaxel. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=132 SRC="FIGDIR/small/680794v3_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@1fdb8a8org.highwire.dtl.DTLVardef@6648acorg.highwire.dtl.DTLVardef@12d301aorg.highwire.dtl.DTLVardef@1b1370f_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗