Background: The very aggressive nature and low survival rate of pancreatic ductal adenocarcinoma (PDAC) dictates the necessity to find novel efficacious therapies. Recent evidence suggests that phosphoinositide 3-kinase (PI3K) and 3-phosphoinositide-dependent protein kinase 1 (PDK1) are key effectors of oncogenic KRAS in PDAC. Herein, we report the role and mechanism of action of PDK1, a protein kinase of the AGC family, in PDAC. Methods: PDAC cell lines were treated with selective PDK1 inhibitors or transfected with specific PDK1-targeting siRNAs. In vitro and in vivo assays were performed to investigate the functional role of PDK1 in PDAC. Specifically, anchorage-dependent and anchorage-independent growth was assessed in PDAC cells upon inhibition or downregulation of PDK1. Detailed investigation of the effect of PDK1 inhibition/downregulation on specific signalling pathways was also performed by Western blotting analysis. A xenograft tumour mouse model was used to determine the effect of pharmacological inhibition of PDK1 on PDAC cells growth in vivo. Results: Treatment with specific inhibitors of PDK1 impaired anchorage-dependent and anchorage-independent growth of pancreatic cancer cell lines, as well as pancreatic tumour growth in a xenograft model. Mechanistically, inhibition or downregulation of PDK1 resulted in reduced activation of the serum/glucocorticoid regulated kinase family member 3 and subsequent reduced phosphorylation of its target N-Myc downstream regulated 1. Additionally, we found that combination of sub-optimal concentrations of inhibitors selective for PDK1 and the class IB PI3K isoform p110γinhibits pancreatic cancer cell growth and colonies formation more potently than each single treatment. Conclusions: Our data indicate that PDK1 is a suitable target for therapeutic intervention in PDAC and support the clinical development of PDK1 inhibitors for PDAC.

Preclinical validation of 3-phosphoinositide-dependent protein kinase 1 inhibition in pancreatic cancer / Emmanouilidi, A.; Fyffe, C. A.; Ferro, R.; Edling, C. E.; Capone, E.; Sestito, S.; Rapposelli, S.; Lattanzio, R.; Iacobelli, S.; Sala, G.; Maffucci, T.; Falasca, M.. - In: JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH. - ISSN 1756-9966. - 38:1(2019). [10.1186/s13046-019-1191-2]

Preclinical validation of 3-phosphoinositide-dependent protein kinase 1 inhibition in pancreatic cancer

Sestito S.;
2019-01-01

Abstract

Background: The very aggressive nature and low survival rate of pancreatic ductal adenocarcinoma (PDAC) dictates the necessity to find novel efficacious therapies. Recent evidence suggests that phosphoinositide 3-kinase (PI3K) and 3-phosphoinositide-dependent protein kinase 1 (PDK1) are key effectors of oncogenic KRAS in PDAC. Herein, we report the role and mechanism of action of PDK1, a protein kinase of the AGC family, in PDAC. Methods: PDAC cell lines were treated with selective PDK1 inhibitors or transfected with specific PDK1-targeting siRNAs. In vitro and in vivo assays were performed to investigate the functional role of PDK1 in PDAC. Specifically, anchorage-dependent and anchorage-independent growth was assessed in PDAC cells upon inhibition or downregulation of PDK1. Detailed investigation of the effect of PDK1 inhibition/downregulation on specific signalling pathways was also performed by Western blotting analysis. A xenograft tumour mouse model was used to determine the effect of pharmacological inhibition of PDK1 on PDAC cells growth in vivo. Results: Treatment with specific inhibitors of PDK1 impaired anchorage-dependent and anchorage-independent growth of pancreatic cancer cell lines, as well as pancreatic tumour growth in a xenograft model. Mechanistically, inhibition or downregulation of PDK1 resulted in reduced activation of the serum/glucocorticoid regulated kinase family member 3 and subsequent reduced phosphorylation of its target N-Myc downstream regulated 1. Additionally, we found that combination of sub-optimal concentrations of inhibitors selective for PDK1 and the class IB PI3K isoform p110γinhibits pancreatic cancer cell growth and colonies formation more potently than each single treatment. Conclusions: Our data indicate that PDK1 is a suitable target for therapeutic intervention in PDAC and support the clinical development of PDK1 inhibitors for PDAC.
2019
Preclinical validation of 3-phosphoinositide-dependent protein kinase 1 inhibition in pancreatic cancer / Emmanouilidi, A.; Fyffe, C. A.; Ferro, R.; Edling, C. E.; Capone, E.; Sestito, S.; Rapposelli, S.; Lattanzio, R.; Iacobelli, S.; Sala, G.; Maffucci, T.; Falasca, M.. - In: JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH. - ISSN 1756-9966. - 38:1(2019). [10.1186/s13046-019-1191-2]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11388/236193
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