Gemcitabine and CHK1 inhibition potentiate EGFR-directed radioimmunotherapy against pancreatic ductal adenocarcinoma.
OBJECTIVE
To develop effective combination therapy against pancreatic ductal adenocarcinoma (PDAC) with a combination of chemotherapy, CHK1 inhibition, and EGFR-targeted radioimmunotherapy.


METHODS
Maximum tolerated doses were determined for the combination of gemcitabine, the CHK1 inhibitor PF-477736, and Lutetium-177 ((177)Lu)-labeled anti-EGFR antibody. This triple combination therapy was investigated using PDAC models from well-established cell lines, recently established patient-derived cell lines, and fresh patient-derived xenografts. Tumors were investigated for the accumulation of (177)Lu-anti-EGFR antibody, survival of tumor-initiating cells, induction of DNA damage, cell death, and tumor tissue degeneration.


RESULTS
The combination of gemcitabine and CHK1 inhibitor PF-477736 with (177)Lu-anti-EGFR antibody was tolerated in mice. This triplet was effective in established tumors and prevented the recurrence of PDAC in four cell line-derived and one patient-derived xenograft model. This exquisite response was associated with the loss of tumor-initiating cells as measured by flow cytometric analysis and secondary implantation of tumors from treated mice into treatment-naïve mice. Extensive DNA damage, apoptosis, and tumor degeneration were detected in the patient-derived xenograft. Mechanistically, we observed CDC25A stabilization as a result of CHK1 inhibition with consequent inhibition of gemcitabine-induced S-phase arrest as well as a decrease in canonical (ERK1/2 phosphorylation) and noncanonical EGFR signaling (RAD51 degradation) as a result of EGFR inhibition.


CONCLUSIONS
Our study developed an effective combination therapy against PDAC that has potential in the treatment of PDAC.
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom Fares.Al-Ejeh@qimrberghofer.edu.au.
Fares
F
Al-Ejeh
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United KingdomAuthors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
Marina
M
Pajic
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
Wei
W
Shi
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
Murugan
M
Kalimutho
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United KingdomAuthors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
Mariska
M
Miranda
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
Adnan M
AM
Nagrial
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United KingdomAuthors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
Angela
A
Chou
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United KingdomAuthors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
Andrew V
AV
Biankin
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United KingdomAuthors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United KingdomAuthors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medic
Sean M
SM
Grimmond
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United KingdomAuthors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
Michael P
MP
Brown
Authors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United KingdomAuthors' Affiliations: Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland; The Kinghorn Cancer Centre, Cancer Division, Garvan Institute of Medical Research; St Vincent's Clinical School, Faculty of Medicine, University of NSW; Department of Anatomical Pathology, SYDPATH, St Vincent's Hospital, Darlinghurst, New South Wales; Australian Pancreatic Cancer Genome Initiative, for the full list of contributors see http://www.pancreaticcancer.net.au/apgi/collaborators; Cancer Clinical Trials Unit, Royal Adelaide Hospital Cancer Centre, and Centre for Cancer Biology, SA Pathology; School of Medicine, University of Adelaide, Adelaide, Australia; and Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom.
Kum Kum
KK
Khanna
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001570:Benzodiazepinones / Q000494:pharmacology*; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D049109:Cell Proliferation / Q000187:drug effects; D000071877:Checkpoint Kinase 1; D003131:Combined Modality Therapy; D004249:DNA Damage / Q000187:drug effects; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004357:Drug Synergism; D066246:ErbB Receptors / Q000037:antagonists & inhibitors*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D010766:Phosphorylation / Q000187:drug effects; D011494:Protein Kinases / Q000737:chemistry*; D011720:Pyrazoles / Q000494:pharmacology*; D016499:Radioimmunotherapy; D015398:Signal Transduction / Q000187:drug effects; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays; D000093542:Gemcitabine
D000911:Antibodies, Monoclonal; D000964:Antimetabolites, Antineoplastic; D001570:Benzodiazepinones; C532366:PF 00477736; D011720:Pyrazoles; D003841:Deoxycytidine; D011494:Protein Kinases; D066246:ErbB Receptors; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; C000605869:Chek1 protein, mouse; D000093542:Gemcitabine