Ascorbate-based biomarkers for predicting radiation response in prostate cancer

基于抗坏血酸的生物标志物用于预测前列腺癌的放射反应

• 批准号: 8276628
• 负责人: David M Wilson
• 金额: $ 50.01万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-24 至 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8276628
• 关键词: Address; Adenocarcinoma; Antioxidants; Ascorbic Acid; Behavior; Bicarbonates; Biochemical; Biological Markers; Biopsy; Bioreactors; Brain; Brain Neoplasms; Cancer Model; Cancer Patient; Cells; Characteristics; Chemical Structure; Clinic; Clinical; Comparative Study; Complement; Coupled; Data; Dehydroascorbic Acid; Development; Diagnosis; Disease; Equilibrium; Failure; Fructose; Fumarates; Generations; Glucose; Glucose Transporter; Glutathione; Glutathione Reductase; Glycine; Hexoses; Human; Image; Imaging Techniques; In Vitro; Infusion procedures; Kidney; Label; Laboratories; Lactate Dehydrogenase; Literature; Liver; Liver neoplasms; Magic; Magnetic Resonance Imaging; Malignant Neoplasms; Malignant neoplasm of prostate; Mediating; Metabolism; Methods; Modality; Modeling; Molecular; Molecular Probes; Motivation; Mus; NADP; Necrosis; Nuclear; Oncogenic; Organ; Oxidation-Reduction; PC3 cell line; Pathologic; Patients; Physiological Processes; Positron-Emission Tomography; Prostate; Prostatic Neoplasms; Pyruvate; Radiation; Radiation therapy; Radioisotopes; Reaction; Reactive Oxygen Species; Reporting; Resistance; Resolution; SLC2A1 gene; Signal Transduction; Spectrum Analysis; Techniques; Technology; Therapeutic; Tissues; Transgenic Organisms; Translations; Treatment Protocols; Validation; Work; ascorbate; base; cancer cell; chemical reduction; chemotherapy; cytotoxic; dehydroascorbate; glutaredoxin; imaging modality; improved; in vivo; malignant breast neoplasm; molecular imaging; pre-clinical therapy; rapid detection; response; sensor; therapy resistant; treatment planning; treatment response; tumor; uptake

DESCRIPTION (provided by applicant): Remarkable progress has been made over the last decade in the characterization of in vivo metabolism using hyperpolarized (HP) 13C spectroscopy, with profound implications for the diagnosis and treatment of human cancers. The majority of studies have focused on metabolism of [1-13C] pyruvate by lactate dehydrogenase (LDH), which occurs to a larger extent in cancer and has been correlated with pathologic grade in a murine prostate tumor model. Although the molecular requirements of dynamic nuclear polarization (DNP) are rather strict, several additional hyperpolarized 13C agents have been developed that are potential markers for pH (13C bicarbonate), hexose metabolism ([2-13C] fructose), and necrosis ([1,4-13C] fumarate). More recently, we have developed the redox sensor [1-13C] dehydroascorbate (DHA), an oxidized version of Vitamin C that shares an uptake mechanism with glucose. This new probe demonstrates rapid in vivo reduction to [1-13C] Vitamin C, and is the principal agent used for the Specific Aims of this R01 proposal. In the proposed project, this new probe is employed to address the redox adaptation of tumors, which accumulate large quantities of GSH and other antioxidants, conferring resistance to therapies that are ROS- dependent, including radiation. Prostate cancer was chosen since (1) radiation therapy is a mainstay of treatment (2) several in vitro studies have implicated GSH and other redox components in resistance and (3) non-invasive biomarkers for disease aggressiveness are lacking. Our preliminary 1H studies on primary prostate cancer cells using high resolution magic-angle spinning (HR-MAS) NMR indicate high levels of GSH, and in vivo murine studies using HP [1-13C] DHA demonstrate reduction in organs that are known to be rich in GSH, including the liver, kidneys, and brain. Furthermore, numerous reports in the literature have established that reduction of DHA to VitC is GSH-mediated. However, other redox mechanisms are certainly possible for the reduction of HP [1-13C] DHA observed in vivo, and our first studies will determine which cellular redox (or transport) components are involved (Specific Aim 1). We will then turn to studies validating the use of HP [1- 13C] DHA to determine cancer aggressiveness, and predict response to radiation therapy in a murine prostate cancer (TRAMP) model (Specific Aim 2). Finally, we will compare this new 13C probe to related 18F ascorbates as well as to [2-deoxy-2-18F] fluoro-D-glucose (FDG), the radioisotope used in the vast majority of clinical positron emission tomography (PET) studies (Specific Aim 3). We anticipate HP 13C MRI emerging as an important technology to complement existing molecular imaging methods, including PET, and comparative studies (employing structurally or mechanistically related probes) will be important to validate both modalities. Our justification for pursuing 18F ascorbate probes is twofold: (1) to determine whether ascorbate-based PET probes demonstrate similar in vivo characteristics to HP [1-13C] DHA and (2) to compare the ability of PET and HP methods to predict tumor aggressiveness/ treatment response in prostate cancer. PUBLIC HEALTH RELEVANCE: This proposal describes a new MRI technology that can potentially both determine prostate cancer aggressiveness, and predict how patients will respond to radiation therapy. Potential advantages include avoiding unnecessary biopsies, optimizing treatment regimens, and identifying appropriate response to therapy non-invasively. The project also compares this cutting-edge MRI technology to a method already used in the clinic, positron emission tomography (PET) in order to address how these two complementary techniques might best serve the needs of prostate cancer patients.