University Times

Research expanded on Space Station

Rocky S. Tuan, director of the Cellular and Molecular Engineering Lab and faculty member in the Department of Orthopaedic Surgery at the School of Medicine, has received a grant from the Center for the Advancement of Science in Space (CASIS) to continue his work on a 3-D microphysiological system to be conducted on board the International Space Station (ISS) to evaluate the accelerated aging and degeneration process of bones that occurs in space.

Said Tuan: “Studying such rapid progression of the disease offers great advantages to developing treatments for osteoporosis faster and more effectively, in ways that are not possible on Earth. Our research will benefit not only the health of astronauts for long stays in space on the ISS or a future journey to Mars, but also will help people on Earth, providing capabilities for the screening of drug therapies, enhancing personalized medicine and developing bioreactor technologies for tissue engineering.”

The award is part of the 3-D Microphysical Systems for Organs-On-Chips Grand Challenge by CASIS, which was chosen by NASA in 2011 to be the sole manager of the ISS U.S. National Laboratory.

Tuan also is associate director of the McGowan Institute for Regenerative Medicine and director of the Center for Military Medicine Research.

The award, he said, will aid “work on developing veritable models for skeletal tissues that may be used to understand the mechanisms of disease and to expedite drug screening for degenerative conditions such as osteoporosis and osteoarthritis.”

The MPS project has been partially funded by the Ri.MED Foundation, a collaboration between Italy’s government, Pitt and UPMC, based in Palermo, Italy.

Diagnosing multiple conditions with drop of blood

Researchers at the Graduate School of Public Health have developed a unique method for detecting antibodies in the blood of patients in a proof-of-principle study that opens the door to development of simple diagnostic tests for diseases for which no microbial cause is known, including autoimmune diseases, cancers and other conditions.

The results, reported in the Journal of Immunological Methods, are the first evidence that it is possible to develop blood tests for any infectious disease by screening random libraries of nonbiological molecular shapes.

Said senior author Donald S. Burke, dean and director of the Center for Vaccine Research: “This ‘needle-in-a-molecular- haystack’ approach is a new way to develop diagnostic assays. The method does not rely on starting with known viral components. This is important because there are conditions for which there isn’t a known antigen, such as newly emerged epidemics, autoimmune diseases or even responses to traumatic injury.”

When a person’s immune system is faced with an antigen or foreign invader, such as an infectious disease, or even an injury with tissue damage, it responds by producing antibodies. Like puzzle pieces, specific parts of the surface of these antibodies fit to the shape of the molecules on the invader or the damaged tissue.

The researchers used a technique pioneered by co-author Thomas Kodadek of the Scripps Research Institute that synthesizes random molecular shapes called “peptoids” hooked onto microscopic plastic beads. The technique can produce millions of molecular shapes. The peptoids are not organic, but if they match to the corresponding shape on an antibody, that antibody will connect to them, allowing the scientist to pull out that bead and examine that peptoid and its corresponding antibody.

Using this technique, Burke’s team chemically generated a huge library of random molecular shapes. Then, using blood from HIV-infected patients and from non-infected people, the researchers screened a million of these random molecular shapes to find the ones that bound only to antibodies present in the blood of HIV-infected patients, but not the healthy controls.

No HIV proteins or structures were used to construct or select the peptoids, but the approach nonetheless successfully led to selection of the best molecular shapes to use in screening for HIV antibodies.

The team then resynthesized that HIV-antibody-targeting peptoid in mass and tested it by screening hundreds of samples from the Multicenter AIDS Cohort Study (MACS), a confidential research study of the natural history of treated and untreated HIV/AIDS in men who have sex with men (supported by the National Institutes of Health).

Study co-author Charles Rinaldo, chair of the Department of Infectious Diseases and Microbiology and director of the Pittsburgh arm of the MACS, selected the samples, but blinded the testers to which samples were HIV-positive or -negative. The test distinguished between the samples of HIV-positive blood and HIV-negative blood with a high degree of accuracy.

“This technology means that we may be able to take a single drop of blood from a patient and detect antibodies to all manner of infections, cancers or other conditions they may be carrying or been exposed to,” said Burke, who also holds the UPMC-Jonas Salk Chair of Global Health. “We hope that this is the first step toward development of an ‘Epi-chip’ that can be used to reconstruct a person’s entire exposure history.”

Additional Pitt co-authors on this study were Tricia L. Gearhart, Ronald C. Montelaro, Mark E. Schurdak, Yongseok Park, Kazi Islam, Raymond Yurko and Ernesto T.A. Marques Jr. A colleague from the University of California-San Francisco also contributed.

This work was funded by the Bill and Melinda Gates Foundation.

Key found to neurodegeneration in Parkinson’s

Researchers at the School of Medicine have uncovered a major reason why the Parkinson’s-related protein alpha-synuclein, a major constituent of the Lewy bodies that are the pathological hallmark of Parkinson’s disease (PD), is toxic to neurons in the brain.

The finding has the potential to lead to new therapies that could slow or stop progression of the devastating illness. The new research appears online in Science Translational Medicine.

PD is a degenerative neurological disease characterized by tremor, slowness, and gait and balance difficulties, and it affects about 1 million people in the United States. The symptoms are caused by the degeneration and loss of neurons in the brain, particularly those crucial for the initiation and coordination of movement.

Current treatments for PD can reduce symptoms, but they do not slow the inevitable worsening of the disease. To slow or halt illness progression, scientists must first determine why and how the neurons are dying
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Degenerating neurons contain large clumps of a protein called alpha-synuclein. People whose cells make too much alpha-synuclein or make a mutated form of the protein are at high risk of developing PD because of the protein’s toxicity, researchers found. Scientists also demonstrated that the accumulation of alpha-synuclein in PD is toxic because it disrupts the normal functioning of mitochondria, the tiny powerhouses responsible for generating a cell’s energy.

Lead investigator is J. Timothy Greenamyre, Love Family Professor of Neurology in the School of Medicine and director of the Pittsburgh Institute for Neurodegenerative Diseases. PIND’s goal is an integrated, interdisciplinary approach to the study of neurodegenerative diseases and their mechanisms, with the aim of transforming cutting-edge science into novel therapies and diagnostics that directly benefit individuals affected by neurodegenerative diseases.

In the new study, Greenamyre and his team — led by co-authors Roberto Di Maio and Paul Barrett, both of PIND — used a rodent model of PD to show how alpha-synuclein disrupts mitochondrial function. They found that by attaching to a mitochondrial protein called TOM20, alpha-synuclein prevented the mitochondria from functioning optimally, which resulted in the production of less energy and more damaging cellular waste.

Ultimately, this interaction between alpha-synuclein and TOM20 leads to neurodegeneration, Greenamyre explained.

The researchers then confirmed their animal findings in brain tissue from people with PD.

Said Greenamyre: “The effects of alpha-synuclein on mitochondria are like making a perfectly good coal-fueled power plant extremely inefficient, so it not only fails to make enough electricity, but also creates too much toxic pollution.”

Using cell cultures, the research team also found two ways to prevent the toxicity caused by alpha-synuclein: gene therapy that forced the neurons to make more TOM20 protein protected them from the alpha-synuclein and a protein that was able to prevent alpha-synuclein from sticking to TOM20 prevented alpha-synuclein’s harmful effects on mitochondria.

While more research is needed to determine whether these approaches could help PD patients, Greenamyre is optimistic that one or both ultimately may make it into human clinical trials in an effort to slow or halt the progression of PD.

Co-authors from Pitt, all of PIND, were Charleen Chu, Edward Burton, Teresa Hastings, Eric Hoffman, Caitlyn Barrett, Alevtina Zharikov, Anupom Borah, Xiaoping Hu and Jennifer McCoy.

The work was supported by the DSF Charitable Foundation, the Ri.MED Foundation, the Consolidated Anti-Aging Foundation, the National Institutes of Health (NIH), the United States Department of Veterans’ Affairs, the Blechman Foundation, the American Parkinson Disease Association and the Department of Biotechnology, Government of India.

Immunotherapies improve 2 cancer treatments

Immunotherapy doubles overall survival and improves quality of life, with fewer side effects, in a treatment-resistant and rapidly progressing form of head and neck carcinoma, reports a large, randomized international trial co-led by investigators at the University of Pittsburgh Cancer Institute (UPCI). The new trial was considered so successful that it was stopped early to allow patients in the comparison group to receive the new drug.

Findings from the international CheckMate-141 phase III clinical trial were presented at the annual American Society of Clinical Oncology (ASCO) meeting. A subset of the results were presented at the American Association for Cancer Research meeting earlier this year.

The new drug, nivolumab, which belongs to a class of drugs known as immunotherapeutics, enables the body’s immune system to destroy cancer cells. It currently is approved to treat certain types of cancers, including melanoma and lung cancer.

The trial enrolled 361 patients with recurrent or metastatic head and neck squamous cell carcinoma, a rapidly progressing form of the disease with an especially poor prognosis, who had not responded to platinum-based chemotherapy. Patients were randomized to receive either nivolumab or a single type of standard chemotherapy until tumor progression was observed.

The nivolumab group achieved better outcomes than the standard chemotherapy group by all accounts. After 12 months, 36 percent of the nivolumab group was alive, compared to just 17 percent of the standard chemotherapy group.

Nivolumab treatment also doubled the number of patients whose tumors shrank, and the number whose disease had not progressed after six months of treatment. Importantly, these benefits were achieved with just one-third the rate of serious adverse events reported in the standard chemotherapy group.

In addition, on average, patients receiving nivolumab reported that their quality of life remained stable or improved throughout the study, while those in the chemotherapy group reported a decline.

While nivolumab improved survival rates in the overall study population, it appeared to be most successful in patients whose tumors were positive for the human papillomavirus (HPV). This is important because the fraction of head and neck cancers attributable to HPV infection has increased by 250 percent over the past several decades.

Said the trial’s international co-chair Robert Ferris, UPMC Endowed Professor, chief of the Division of Head and Neck Surgery and co-leader of UPCI’s cancer immunology program: “Unfortunately, most patients in this trial still experienced a progression of their cancer, demonstrating that we still have a lot of work to do. But the future appears brighter than ever before because there is a new class of agents, immunotherapies, which we now know can prolong survival and improve quality of life, with few side effects, in head and neck cancer.”

The research team is working to identify new biomarkers that will allow them to develop a better understanding of how drug resistance develops, and how to best design effective combinations of medications that may improve patient responses.

The trial’s other researchers are from Ohio State University, the University of Texas MD Anderson Cancer Center, Stanford Cancer Institute, the University of Chicago, the University of Michigan and Dana-Farber Cancer Institute.

International collaborators are located at Centre Leon Berard, Centre Antoine Lacassagne and Institut Gustave Roussy, all in France; Fondazione IRCCS Istituto Nazionale Tumori in Italy; the Institute of Cancer Research in the United Kingdom; University Hospital Essen in Germany; and National Cancer Center Hospital East and Kobe University Hospital, both in Japan.

The trial was funded by the drug manufacturer, Bristol-Myers Squibb, which now is seeking FDA approval for the use of nivolumab in head and neck carcinoma.

In other UPCI research, an existing cancer immunotherapy drug was found to reduce tumor size in some types of rare connective tissue cancers, called sarcomas. Additional analyses of tumor biopsies and blood samples, which will help the researchers better understand which sarcoma subtypes will benefit most from the new treatment, are underway.

Interim results from the phase II clinical trial were presented at ASCO by principal investigator Hussein Abdul-Hassan Tawbi, formerly of UPCI and currently a faculty member at the University of Texas MD Anderson Cancer Center.

Sarcoma is a rare disease, encompassing less than 1 percent of adult cancers, and the available treatments are limited, so the need for new therapies is high, explained the current lead investigator for the Pittsburgh site, Melissa Burgess, faculty member in medicine at UPCI.

Said Burgess: “This is a pivotal trial for sarcoma, the first and largest trial to be conducted using this specific immunotherapeutic approach. What makes this trial special is that we collected biopsies and blood samples to really study how the treatment is working or not working in these patients. These immune monitoring studies will offer unique insights into the biology of immunotherapy in sarcoma.”

Immunotherapies work by using a patient’s own immune cells to target cancer cells. The new trial examined the safety and effect of pembrolizumab, which currently is approved for use in advanced melanoma and certain types of advanced lung cancer, on tumor size in four types of soft tissue sarcomas and three types of bone sarcomas.

UPCI, the first of 12 sites to enroll subjects, contributed approximately one-quarter of the 80 total patients.

Patients received the drug every three weeks. Tumor assessments began at eight weeks and were conducted every 12 weeks thereafter. The trial enrolled on a rolling basis and is still in progress, so not all patients have received the drug for the same amount of time.

About 20 percent of patients in the combined soft tissue sarcoma group showed a reduction in tumor size during at least one time point. However, when the researchers looked at the sarcoma subtypes individually, they found one with especially promising results: 44 percent of patients with undifferentiated pleomorphic sarcoma experienced a reduction in tumor size. Encouraging improvements in tumor size also were found in two subtypes of bone sarcomas, osteosarcoma and chondrosarcoma, Burgess noted.

“Unfortunately, these early results suggest that there is limited efficacy of pembrolizumab in the patient population as a whole,” she said.

“However, it’s promising that the drug seems to be beneficial in specific sarcoma subtypes. Our ongoing immune monitoring studies will allow us to better characterize the patients who will most benefit from this therapy for future clinical trials.”

Funding for the trial was provided by Merck & Co., the maker of pembrolizumab; the Sarcoma Alliance for Research Through Collaboration; the Sarcoma Foundation of America; and QuadW Foundation. Some funding for the ongoing studies was provided by local philanthropic support group Pittsburgh Cure Sarcoma.

Nursing studies effects of exerciseon breast cancer

Catherine Bender, faculty member in the School of Nursing, has received funding from the National Cancer Institute for her project, “Influence of Exercise on Neurocognitive Function in Breast Cancer.”

The study aims to determine if moderate aerobic exercise will improve cognitive function, particularly memory, attention and executive function related to endocrine therapy in postmenopausal women with breast cancer.
The grant of more than $600,000 will support a clinical trial in which post-menopausal women with early-stage breast cancer are randomized to receive a six-month, moderate-intensity aerobic exercise intervention or the usual care.

The trial seeks to determine if the intervention improves cognitive function compared to usual care during hormonal therapy and to map the direct effects of exercise on neuroimaging metrics of brain health.

Another goal of this five-year project will be to assess the impact of exercise on cognitive function in light of symptoms such as fatigue, sleep problems, depression and anxiety.

Bender is director of the school’s PhD program.

—Compiled by Marty Levine

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