Title |
18F–FDG-PET/CT and diffusion-weighted MRI for monitoring a BRAF and CDK 4/6 inhibitor combination therapy in a murine model of human melanoma
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Published in |
Cancer Imaging, January 2018
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DOI | 10.1186/s40644-018-0135-y |
Pubmed ID | |
Authors |
Ralf S. Eschbach, Philipp M. Kazmierczak, Maurice M. Heimer, Andrei Todica, Heidrun Hirner-Eppeneder, Moritz J. Schneider, Georg Keinrath, Olga Solyanik, Jessica Olivier, Wolfgang G. Kunz, Maximilian F. Reiser, Peter Bartenstein, Jens Ricke, Clemens C. Cyran |
Abstract |
The purpose of the study was to investigate a novel BRAF and CDK 4/6 inhibitor combination therapy in a murine model of BRAF-V600-mutant human melanoma monitored by 18F-FDG-PET/CT and diffusion-weighted MRI (DW-MRI). Human BRAF-V600-mutant melanoma (A375) xenograft-bearing balb/c nude mice (n = 21) were imaged by 18F-FDG-PET/CT and DW-MRI before (day 0) and after (day 7) a 1-week BRAF and CDK 4/6 inhibitor combination therapy (n = 12; dabrafenib, 20 mg/kg/d; ribociclib, 100 mg/kg/d) or placebo (n = 9). Animals were scanned on a small animal PET after intravenous administration of 20 MBq 18F-FDG. Tumor glucose uptake was calculated as the tumor-to-liver-ratio (TTL). Unenhanced CT data sets were subsequently acquired for anatomic coregistration. Tumor diffusivity was assessed by DW-MRI using the apparent diffusion coefficient (ADC). Anti-tumor therapy effects were assessed by ex vivo immunohistochemistry for validation purposes (microvascular density - CD31; tumor cell proliferation - Ki-67). Tumor glucose uptake was significantly suppressed under therapy (∆TTLTherapy - 1.00 ± 0.53 vs. ∆TTLControl 0.85 ± 1.21; p < 0.001). In addition, tumor diffusivity was significantly elevated following the BRAF and CDK 4/6 inhibitor combination therapy (∆ADCTherapy 0.12 ± 0.14 × 10-3 mm2/s; ∆ADCControl - 0.12 ± 0.06 × 10-3 mm2/s; p < 0.001). Immunohistochemistry revealed a significant suppression of microvascular density (CD31, 147 ± 48 vs. 287 ± 92; p = 0.001) and proliferation (Ki-67, 3718 ± 998 vs. 5389 ± 1332; p = 0.007) in the therapy compared to the control group. A novel BRAF and CDK 4/6 inhibitor combination therapy exhibited significant anti-angiogenic and anti-proliferative effects in experimental human melanomas, monitored by 18F-FDG-PET/CT and DW-MRI. |
X Demographics
Geographical breakdown
Country | Count | As % |
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United Kingdom | 2 | 67% |
Unknown | 1 | 33% |
Demographic breakdown
Type | Count | As % |
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Members of the public | 1 | 33% |
Practitioners (doctors, other healthcare professionals) | 1 | 33% |
Science communicators (journalists, bloggers, editors) | 1 | 33% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
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Unknown | 20 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
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Researcher | 3 | 15% |
Student > Postgraduate | 2 | 10% |
Student > Master | 2 | 10% |
Student > Ph. D. Student | 2 | 10% |
Student > Doctoral Student | 1 | 5% |
Other | 3 | 15% |
Unknown | 7 | 35% |
Readers by discipline | Count | As % |
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Medicine and Dentistry | 4 | 20% |
Biochemistry, Genetics and Molecular Biology | 2 | 10% |
Veterinary Science and Veterinary Medicine | 1 | 5% |
Pharmacology, Toxicology and Pharmaceutical Science | 1 | 5% |
Linguistics | 1 | 5% |
Other | 5 | 25% |
Unknown | 6 | 30% |