DKK3 reduces the killing
capacity of NK cells for CRC cells in
vitro. (A) Kaplan–Meier plots showing the effect of DKK3 (top)
and DKK4 (bottom) expression on survival probability in the TCGA-COAD
cohort. Left panels include the whole cohort, middle panels show patients
with mutations in SMAD4, and right panels show patients without SMAD4
mutations. (B) Schematic overview of killing assays using CRC cells
and NK cells. NK-92MI cells are incubated for 24h with recombinant
DKK-proteins after which they are co-cultured with HT29 cells. After
24h of coculture, non-adherent cells are removed and adherent cells
are dissociated and counted by flow cytometry (C) Schematic overview
of killing assays using patient-derived CRC tumor organoids and matched
CTLs. Patient derived organoids (PDOs) are incubated with IFNγ
for 24h after which they are cocultured with CTLs in combination with
recombinant DKK proteins. After 72h, non-adherent cells are removed
and adherent cells are dissociated and measured by flow cytometry
(D) Dot plots showing the effect of DKK3 and DKK4 on the antitumor
capacity of NK cells (top) and CTLs (bottom). No CTL indicates the
control condition, where no CTLs are added to the tumor organoids; n = 3 independent replicates; error bars represent SEM.
n.s: not significant.