Multiparametric High-Content Cell Painting Identifies Copper Ionophores as Selective Modulators of Esophageal Cancer Phenotypes

Esophageal adenocarcinoma
is of increasing global concern due to
increasing incidence, a lack of effective treatments, and poor prognosis.
Therapeutic target discovery and clinical trials have been hindered
by the heterogeneity of the disease, the lack of “druggable”
driver mutations, and the dominance of large-scale genomic rearrangements.
We have previously undertaken a comprehensive small-molecule phenotypic
screen using the high-content Cell Painting assay to quantify the
morphological response to a total of 19,555 small molecules across
a panel of genetically distinct human esophageal cell lines to identify
new therapeutic targets and small molecules for the treatment of esophageal
adenocarcinoma. In this current study, we report for the first time
the dose–response validation studies for the 72 screening hits
from the target-annotated LOPAC and Prestwick FDA-approved compound
libraries and the full list of 51 validated esophageal adenocarcinoma-selective
small molecules (71% validation rate). We then focus on the most potent
and selective hit molecules, elesclomol, disulfiram, and ammonium
pyrrolidinedithiocarbamate. Using a multipronged, multitechnology
approach, we uncover a unified mechanism of action and a vulnerability
in esophageal adenocarcinoma toward copper-dependent cell death that
could be targeted in the future.