# Targeting in vitro vasculogenic mimicry and associated stemness transcriptional signature in human ovarian cancer cell models: new emerging roles of caffeic acid phenethyl ester synthetic analogs

## TL;DR

This study explores how synthetic versions of a plant compound can target cancer stem cells and reduce tumor growth in ovarian cancer by inhibiting vasculogenic mimicry.

## Contribution

The study identifies two synthetic ketone analogs of caffeic acid phenethyl ester with distinct effects on cancer stem cell networks and vasculogenic mimicry in ovarian cancer.

## Key findings

- Ketone analog (5) strongly inhibits vasculogenic mimicry and represses key stemness markers in both ovarian cancer cell models.
- Ketone analog (4) shows moderate, pathway-selective inhibition of vasculogenic mimicry, mainly in one cell model.
- Both analogs inhibit cell migration, but only analog (5) broadly suppresses developmental signaling and epithelial-mesenchymal transition drivers.

## Abstract

Cancer stem cells (CSC) can sustain tumor growth and therapeutic resistance in part through their contribution to vasculogenic mimicry (VM) in ovarian cancers. Pharmacological targeting of CSC-associated transcriptional programs could represent a promising strategy to overcome recurrence and metastasis. While preclinical studies show caffeic acid phenethyl ester (CAPE), a plant-derived metabolite, can sensitize tumors to chemotherapy and radiotherapy, little is known about its anti-VM properties.

CAPE (1) and four closely related synthetic analogs were evaluated for their ability to inhibit in vitro VM on Matrigel and to remodel CSC molecular signature at the transcriptomic level in human SKOV3 ovarian adenocarcinoma cells and in human ES-2 ovarian clear cell carcinoma. The best analogs were further used for transcriptomic profiling of an 89-gene CSC panel using hierarchical clustering and differential expression analysis.

While CAPE (1) and analogs (2–3) were ineffective, the ketone analog (4) with 3,4-dihydroxy substitution exerted a moderate, pathway-selective effect, reducing VM completely in ES-2 cells, but only partially in SKOV3 cells. In contrast, the ketone analog (5) with 2,5-dihydroxy substitution induced a profound inhibition of VM in both cell models tested and of CSC identity, strongly repressing stemness markers PROM1, ABCG2, ALDH1A1, and pluripotency network regulators SOX2, NANOG, LIN28, alongside broad inhibition of Notch/Wnt/Hedgehog developmental signaling and EMT drivers. Both analogs inhibited serum-induced chemotactic cell migration.

These divergent profiles suggest that CAPE’s synthetic ketone analogs (4) and (5) differentially regulate CSC networks and VM, with (5) producing a coordinated reduction of stemness and plasticity molecular signatures. These findings highlight mechanistic divergence in CSC-targeting strategies that can be attributed solely to the dihydroxy substitution pattern of the two analogs. As effective CSC phenotypic depletion is critical in preventing recurrence and metastasis in ovarian cancer, ketone analog (4) may serve as a selective modulator in contexts requiring partial CSC inhibition. Ketone analog (5) broad pharmacological suppression of CSC programs could position it as a promising candidate for combination therapy to overcome VM-driven chemoresistance.