Enzyme-inhibition could revolutionize molecular imaging

Oncologic imaging just got better with a naturally occurring compound that protects injected radiopeptide imaging agents from enzymatic degradation in the body

2014-06-09

(Press-News.org) St. Louis, Mo. (June 9, 2014) – The prominent role a single enzyme plays in cancer imaging has eluded researchers for years, but not anymore. This discovery could pave new avenues in nuclear medicine. The enzyme, called neutral endopeptidase (NEP), has a way of breaking down most radiopeptide imaging agents in the body. Researchers have developed an elegant new concept that improves molecular imaging, according to study results presented during the Society of Nuclear Medicine and Molecular Imaging's 2014 Annual Meeting.

The sneaky enzyme has evaded studies with peptide tracers until now because it dwells not in tested blood serum but along the walls of blood vessels and other tissues. In order to combat the degradation of circulating radiopeptides, researchers co-injected a NEP inhibitor called phosphoramidon, derived from bacteria, at the same time as an agent for imaging with single photon emission computed tomography and computed tomography (SPECT/CT). They then applied this method of enzyme inhibition in multiple imaging studies involving a range of radionuclide and peptide counterparts. The results of this research showed consistent success—up to 40 times the circulating radiopeptides when protected with phosphoramidon, compared to unprotected controls. This means the simple co-injection of an enzyme inhibitor promotes dramatically improved bioavailability and metabolic stability of radiopeptide imaging agents leading to higher uptake of the agent within targeted tumors and therefore better cancer imaging.

"Oncologists have long sought a powerful 'magic bullet' that can find tumors wherever they hide in the body so that they can be imaged and then destroyed," said Marion de Jong, PhD, a principal researcher for this study conducted at Erasmus Medical Center in Rotterdam, The Netherlands in cooperation with NCSR 'Demokritos' Athens, Greece. "Following this innovative approach, we have been able to induce, for the first time, an impressive improvement in the level of circulating and viable radiopeptides, leading to a spectacular increase in tumor uptake. Enzyme-inhibition in the body could translate into higher diagnostic sensitivity and improved therapeutic efficacy of radiopeptide drugs in cancer patients."

Not only were circulating radiopeptides increased in small animal models of varying tumor types, but the accumulation of radiopeptides also peaked at 14 times that of controls, which had not been treated with enzyme-inhibiting phosphoramidon. These results were clearly visualized by SPECT/CT imaging.

INFORMATION: Scientific Paper 163: Marion de Jong, Eric Krenning, Nuclear Medicine, Erasmus MC, Rotterdam, Netherlands; Berthold Nock, Theodosia Maina, Molecular Radiopharmacy, INRASTES, NCSR 'Demokritos,' Athens, Greece, "In vivo enzyme inhibition - A new promising route toward higher diagnostic sensitivity and therapeutic efficacy of tumor-directed radiopeptides," SNMMI's 61th Annual Meeting, June 7, 2014, St. Louis, Missouri.

About the Society of Nuclear Medicine and Molecular Imaging

The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and medical organization dedicated to raising public awareness about nuclear medicine and molecular imaging, a vital element of today's medical practice that adds an additional dimension to diagnosis, changing the way common and devastating diseases are understood and treated and helping provide patients with the best health care possible.

SNMMI's more than 18,000 members set the standard for molecular imaging and nuclear medicine practice by creating guidelines, sharing information through journals and meetings and leading advocacy on key issues that affect molecular imaging and therapy research and practice. For more information, visit http://www.snmmi.org.

ELSE PRESS RELEASES FROM THIS DATE:

Molecular imaging gets to the root of rheumatoid arthritis

2014-06-09

St. Louis, Mo. (June 9, 2014) – Rheumatoid arthritis causes chronic pain for almost half of adults by the time they retire, but a new molecular imaging technique can visualize inflammation in the joints, giving doctors a clear read on chronic pain and possible joint destruction, say researchers at the Society of Nuclear Medicine and Molecular Imaging's 2014 Annual Meeting. In order to image arthritis inside the joints, researchers used multiple molecular imaging systems, positron emission tomography (PET) and single photon emission tomography (SPECT), both of which image ...

Depression in the elderly linked to Alzheimer's risk

2014-06-09

St. Louis, Mo. (June 9, 2014) – Many people develop depression in the latest stages of life, but until now doctors had no idea that it could point to a build up of a naturally occurring protein in the brain called beta-amyloid, a hallmark of Alzheimer's disease. In fact, late-life depression could become a major risk factor for developing Alzheimer's faster than others, according to research unveiled at the Society of Nuclear Medicine and Molecular Imaging's 2014 Annual Meeting. Alzheimer's disease is a currently incurable neurodegenerative disease with marked protein ...

REM sleep disturbance signals future neurodegenerative disease

2014-06-09

St. Louis, Mo. (June 9, 2014) – How many millions of people suffer from sleep disturbance? One sleep disorder in particular, called REM behavior disorder, could be a sign of impending neurodegenerative disease, including Parkinson's and dementia, say scientists presenting their research at the Society of Nuclear Medicine and Molecular Imaging's 2014 Annual Meeting. Researchers are not sure why spontaneous and unexplained disturbance in REM sleep should lead to a neurodegenerative disease like Parkinson's, but new longitudinal imaging data show a clear correlation between ...

A few circulating cancer cells could cue risk of metastases

2014-06-09

St. Louis, Mo. (June 9, 2014) – A simple noninvasive blood test matched with state-of-the-art molecular imaging of individual cells could help oncologists understand their patients' chances of survival, say researchers at the Society of Nuclear Medicine and Molecular Imaging's 2014 Annual Meeting. Metastasis accounts for an estimated 90 percent of cancer deaths. For decades, researchers tried to develop a way to gauge a cancer's risk of metastasizing from a blood sample—the long-sought-after liquid biopsy. Today there are numerous methods available to isolate lone cells. ...

Molecular imaging finds novel way to knock down breast cancer

2014-06-09

St. Louis, Mo. (June 9, 2014) – For years researchers have been developing molecular imaging techniques that visualize hormonally active breast cancer cells—specifically those testing positive for human epidermal growth factor receptor 2 (HER2). A recent innovation in breast cancer biomarkers seeks the HER3 receptor instead, which could mean more comprehensive breast cancer imaging and potential treatments, say experts presenting data during the Society of Nuclear Medicine and Molecular Imaging's 2014 Annual Meeting. Breast cancer is one of the most prevalent forms of ...

PSMA-based imaging traces even treatment-resistant prostate cancer

2014-06-09

St. Louis, Mo. (June 9, 2014) – Anti-androgen hormonal therapy, also called chemical castration, can be an important defense against further disease progression for patients with prostate cancer that has traveled and grown in other areas, or metastasized—but some cases simply do not respond to this treatment. A groundbreaking molecular imaging agent has been developed to help clinicians find as much cancer as possible, whether it is responding favorably or not, in an effort to improve clinical decision making for these patients, say researchers at the Society of Nuclear ...

Molecular breast imaging protocol unmasks more cancer

2014-06-09

St. Louis, Mo. (June 9, 2014) – Patients with advanced breast cancer that may have spread to their lymph nodes could benefit from a more robust dose of a molecular imaging agent called Tc-99m filtered sulfur colloid when undergoing lymphoscintigraphy, a functional imaging technique that scouts new cancer as it begins to metastasize. Best results also indicate that imaging could be improved by injecting the agent the day prior to surgical resection, according to research unveiled at the Society of Nuclear Medicine and Molecular Imaging's 2014 Annual Meeting. "The innovative ...

Presurgical SPECT/CT shows more cancer than current standard

2014-06-09

St. Louis, Mo. (June 9, 2014) – Startling data from an international multi-center trial provide growing evidence that sentinel node imaging is more effectively accomplished with hybrid functional imaging with single photon emission computed tomography and computed tomography (SPECT/CT) than with another molecular imaging technique called lymphoscintigraphy. This conclusion held after imaging a range of cancers displaying a variety of lymphatic drainage types associated with melanoma, an aggressive skin cancer; breast carcinoma; and malignancies of the pelvis, such as prostate ...

Connecting dead ends increases power grid stability

2014-06-09

Climate change mitigation strategies such as the German Energiewende require linking vast numbers of new power generation facilities to the grid. As the input from many renewable sources is rather volatile, depending on how much the wind blows or the sun shines, there's a higher risk of local power instabilities and eventually blackouts. Scientists from the Potsdam Institute for Climate Impact Research (PIK) now employed a novel concept from nonlinear systems analysis called basin stability to tackle this challenge. They found that connecting dead ends can significantly ...

Einstein & Montefiore present research at American Diabetes Association Scientific Sessions

2014-06-09

June 9, 2014 – (BRONX, NY) – Investigators at Albert Einstein College of Medicine of Yeshiva University and Montefiore Medical Center will present their latest research at the American Diabetes Association's 74th Scientific Sessions. Einstein-Montefiore scientists and clinicians are participating in nearly three dozen presentations, sessions and symposia during the five-day meeting. They will address a range of basic, translational and clinical research topics—from medication adherence in adolescents and the impact on resveratrol and vitamin D on insulin resistance to epigenetic ...

LAST 30 PRESS RELEASES:

Increase in alcohol deaths in England an ‘acute crisis’

Government urged to tackle inequality in ‘low-carbon tech’ like solar panels and electric cars

Moffitt-led international study finds new drug delivery system effective against rare eye cancer

Boston stroke neurologist elected new American Academy of Neurology president

Center for Open Science launches collaborative health research replication initiative

Crystal L. Mackall, MD, FAACR, recognized with the 2025 AACR-Cancer Research Institute Lloyd J. Old Award in Cancer Immunology

A novel strategy for detecting trace-level nanoplastics in aquatic environments: Multi-feature machine learning-enhanced SERS quantification leveraging the coffee ring effect