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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Angiogenesis Inhibitors, Animals, Antibodies, Carcinoma, Pancreatic Ductal, Cell Proliferation, Colforsin, Contrast Media, Ferrosoferric Oxide, Hedgehog Proteins, Humans, Injections, Intravenous, Magnetic Resonance Imaging, Mice, Mice, Nude, Nanoparticles, Neovascularization, Pathologic, Pancreatic Neoplasms, Signal Transduction, Veratrum Alkaloids, Xenograft Model Antitumor Assays.
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Does magnetic resonance imaging monitor physiological changes with antihedgehog therapy in pancreatic adenocarcinoma xenograft model? Context: The sonic hedgehog (Shh) pathway has an established role in pancreatic cancer (pancreatic adenocarcinoma [PDAC]). We tested whether magnetic resonance imaging measures of vascular volume fraction (VVF) using magnetic iron oxide nanoparticles are sensitive to the antiangiogenic effect of targeted Shh therapies in a PDAC xenograft model. Pancreatic adenocarcinoma xenograft lines were subcutaneously implanted into nude mice (n = 19 samples within 4 groups). Therapies were targeted to 3 loci of the Shh signaling pathway (anti-Shh antibody, cyclopamine, or forskolin). Magnetic resonance imaging (4.7-T Bruker Pharmascan) was performed (after 1 week of intraperitoneal therapy) before and after intravenous injection of MION-47. Vascular volume fraction was quantified as DeltaR2 (from multicontrast T2 sequences) and normalized to an assumed VVF in muscle of 3%. Linear regression compared VVF to histological indices including microvessel density (MVD), viable gland density (VGD), and proliferative index (PI). In response to anti-Hh treatment, tumors showed a decrease in VGD, PI, MVD, and VVF compared with controls (P < 0.001). Vascular volume fraction was compared with histological indicators of response: PI (R2 = 0.88; P < 0.05), VGD (R2 = 0.87; P< 0.05), and MVD (R2 = 0.85; P < 0.05).
assistant
Magnetic resonance imaging VVF using magnetic iron oxide nanoparticles may serve as a noninvasive measure of biological response to Shh PDAC therapy with easy translation to the clinic. Final Decision: yes