Submission 7
PADI inhibition overcomes the acquisition of resistance after KRAS blockage in pancreatic ductal adenocarcinoma cells
Tuesday-Talks 3-Selected talk-05
Presented by: Francesca Agostini
In pancreatic ductal adenocarcinoma (PDAC) KRAS activating point mutations are frequently observed. KRAS inhibitors specific for the G12C mutation have been developed to selectively target cancer cells. However, KRASG12C cells display metabolic adaptations and rapidly acquire resistance to the treatment. Peptidyl Arginine Deiminases (PADIs) catalyze the conversion of peptidyl-arginine into citrulline residues, influencing the activity of targeted enzymes and modifying the state of the chromatin by histone citrullination. Although there is evidence that PADIs can modulate the activity of enzymes involved in metabolism, the role of these proteins in sustaining cancer cells remains to be clarified.
In this project we aim to evaluate the contribution of PADIs in controlling the metabolic resetting of cancer cells that have acquired resistance to KRAS inhibition.
We studied the PDAC cell line MIA PaCa-2 and evaluated the effect of KRASG12C degradation mediated by the PROTAC LC-2 in combination with PADI inhibition obtained by the pan-PADI inhibitor BB-Cl-amidine. Colony formation assay and biochemical assays were used to evaluate the viability of cancer cells and the metabolic resetting achieved after co-treatment.
In MIA PaCa-2 cells, KRASG12C forced degradation led to PADI1 and PADI3 down-regulation. Conversely, MIA PaCa-2 cells developing LC-2 resistance increased PADI1 and PADI3 protein levels. Interestingly, PADI inhibition with BB-Cl-amidine had a limited effect on viability of MIA PaCa-2 cells if used alone, but displayed a strong synergic anti-neoplastic effect when combined with LC-2 treatment. Indeed, the co-treatment with LC-2 and BB-Cl-amidine rapidly induced apoptosis in PDAC cells, leading to a drastic decrease of ATP level and colony formation.
These data suggest that PADIs play a fundamental role in the metabolic adaptations observed in LC-2 resistant cells. Thus, a combined approach that targets KRASG12C and PADIs appears to be promising in PDAC therapy.
In this project we aim to evaluate the contribution of PADIs in controlling the metabolic resetting of cancer cells that have acquired resistance to KRAS inhibition.
We studied the PDAC cell line MIA PaCa-2 and evaluated the effect of KRASG12C degradation mediated by the PROTAC LC-2 in combination with PADI inhibition obtained by the pan-PADI inhibitor BB-Cl-amidine. Colony formation assay and biochemical assays were used to evaluate the viability of cancer cells and the metabolic resetting achieved after co-treatment.
In MIA PaCa-2 cells, KRASG12C forced degradation led to PADI1 and PADI3 down-regulation. Conversely, MIA PaCa-2 cells developing LC-2 resistance increased PADI1 and PADI3 protein levels. Interestingly, PADI inhibition with BB-Cl-amidine had a limited effect on viability of MIA PaCa-2 cells if used alone, but displayed a strong synergic anti-neoplastic effect when combined with LC-2 treatment. Indeed, the co-treatment with LC-2 and BB-Cl-amidine rapidly induced apoptosis in PDAC cells, leading to a drastic decrease of ATP level and colony formation.
These data suggest that PADIs play a fundamental role in the metabolic adaptations observed in LC-2 resistant cells. Thus, a combined approach that targets KRASG12C and PADIs appears to be promising in PDAC therapy.