Inflammation-cancer feedback loop discovered

At the American Association for Cancer Research (AACR) annual meeting, researchers from the University of Pittsburgh Cancer Institute (UPCI), partner with UPMC CancerCenter, presented new findings hidden within the complex machinery behind the vicious cycle of chronic inflammation and cancer.

Inflammation is an important immune system tool that helps the body rid itself of foreign invaders, such as bacteria. However, chronic inflammation can fuel tumor growth by facilitating formation of cancer blood vessels, supplying nutrients and setting cancerous cells free to colonize other parts of the body.

The basic research into the specific mechanisms promoting cancer inflammation is a critical step in the development of drugs that could interrupt this process.

Said lead author Sandra Cascio, a research associate in the School of Medicine’s Department of Immunology: “In the last 20 years we’ve recognized that chronic inflammation and cancer are connected — long-term inflammation leads to the development of dysplasia and tumor progression. Recently, scientists have provided detailed insights into molecules and cellular pathways linking inflammation and cancer. In our study, we found a new mechanism that had previously escaped us.”

The mechanism is driven by a complex of MUC1, a molecule long studied in the laboratory of senior author and Pitt immunologist Olivera Finn, and p65, a molecule belonging to a protein complex family known to be activated in inflammation.

Cascio and Finn looked for MUC1/p65-mediated epigenetic modifications affecting inflammatory genes. Epigenetics refers to outside factors that modify the activity of a gene, but do not cause a more obvious genetic mutation. They discovered that this complex, found specifically in cancer cells, was causing DNA to be transcribed differently than expected.

“Normally MUC1 is covered in sugar molecules, like leaves cover a tree in spring,” said Cascio. “When it is made by a tumor, it lacks sugar and is more like a tree in fall. Our research shows that this form of MUC1 associates with p65 and regulates transcription of pro-inflammatory cytokine genes in tumor cells. This leads to the recruitment of inflammatory cells into the tumor site. Inflammatory cells, including macrophages, produce additional cytokines that enhance the activity of MUC1 and p65, establishing a continuous positive feedback loop, or a vicious circle, resulting in tumor progression.”

In order to pinpoint this altered pro-inflammatory mechanism in cancer cells, Cascio and her team combed through more than 20 types of epigenetic modifications and 300 factors that allow for the remodeling of chromatin, which are macromolecules in cells that control gene expression and DNA replication.

Specifically, the researchers found that MUC1 and p65 involve an enzyme called the Enhancer of Zeste homolog 2, or EzH2, known to induce epigenetic modifications, in order to prompt chromatin remodeling on cytokine gene promoters.

“Developing drugs that could keep these genes from being improperly turned on and off could interrupt this cancer-inflammation process and stop the tumor growth and spread,” said Cascio. “It’s a promising avenue for future exploration.”

Joshua Sciurba, formerly of Pitt, also participated in this work.

The National Cancer Institute (NCI) of the National Institutes of Health (NIH) and Fondazione RiMED of Palermo, Italy, provided funding.

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New targets for ovarian cancer treatment

Identifying molecular changes that occur in tissue after chemotherapy could be crucial in advancing treatments for ovarian cancer, according to research from Magee-Womens Research Institute and Foundation (MWRIF) and UPCI, presented at the AACR annual meeting.

For years, intraperitoneal chemotherapy, a treatment that involves filling the abdominal cavity with chemotherapy drugs after surgery, has been considered the standard of care for ovarian cancer. According to Shannon Grabosch, a gynecologic oncology fellow at Magee-Womens Hospital and the study’s lead investigator, treatment advances for this disease haven’t moved forward as quickly as they have for other cancers.

Said Grabosch: “The addition of intraperitoneal chemotherapy for women with ovarian cancer was one of the biggest achievements in improving survival outcomes, but unfortunately, we still don’t understand the biological mechanisms by which this works. We wanted to understand what changes occurred to the local tumor environment after chemotherapy was administered, with the idea that these changes could eventually be targets for new, personalized ovarian cancer treatments.”

Grabosch and her team examined peritoneal cavity fluid and peripheral blood samples of 13 patients. The samples were obtained prior to intraperitoneal treatment and after the first and second rounds of chemotherapy. Using multiple sequencing techniques, the researchers identified chemotherapy-induced molecular changes.

“We were able to identify changes in both miRNA and genes which appear to be related to chemotherapy,” said Grabosch. “Furthermore, we identified different, significant changes between the peritoneal cavity and blood samples, proving that the local tumor environment is an underutilized wealth of information. Now we need larger studies to determine whether the changes that occur in the tumor microenvironment after chemotherapy could be potential targets for new, more personalized drugs and to further understand the mechanisms of intraperitoneal chemotherapy.”

Additional Pitt authors from the MWRIF and the Gynecologic Oncology Group, which funded the research, were Anda M. Vlad, Tianzhou Ma, Jyothi Mony, Mary Strange, Joan Brozick, Julia Thaller, George Tseng, Xin Huan, Katie Moore, Kunle Odunsi and Robert P. Edwards.

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Broccoli sprouts may stop head/neck cancer

Broccoli sprout extract protects against oral cancer in mice and proved tolerable in a small group of healthy human volunteers, UPCI researchers announced at the AACR annual meeting.

The results will be explored further in a human clinical trial, which later this year will recruit participants at high risk for head and neck cancer recurrence.

This research is funded through Pitt’s specialized program of research excellence grant in head and neck cancer from the NCI.

Said  lead  author  Julie Bauman, medicine faculty member and codirector of the UPMC Head and Neck Cancer Center of Excellence: “People who are cured of head and neck cancer are still at very high risk for a second cancer in their mouth or throat and, unfortunately, these second cancers are commonly fatal. So we’re developing a safe, natural molecule found in cruciferous vegetables to protect the oral lining where these cancers form.”

Previous studies, including large-scale trials in China, have shown that cruciferous vegetables that have a high concentration of sulforaphane — such as broccoli, cabbage and garden cress — help mitigate the effects of environmental carcinogens.

Bauman collaborated with Daniel E. Johnson, a medicine department colleague and senior scientist in the UPCI head and neck cancer program, to test sulforaphane in the laboratory. For several months, Johnson and his team gave sulforaphane to mice predisposed to oral cancer and found that it significantly reduced the incidence and number of tumors.

Said Johnson: “The clear benefit of sulforaphane in preventing oral cancer in mice raises hope that this well-tolerated compound also may act to prevent oral cancer in humans who face chronic exposure to environmental pollutants and carcinogens.”

Bauman treated 10 healthy volunteers with fruit juice mixed with sulforaphane-rich broccoli sprout extract. The volunteers had no ill effects from the extract and protective changes were detectable in the lining of their mouths, meaning the extract was absorbed and directed to at-risk tissue.

These findings prompted a clinical trial that will recruit 40 volunteers who have been curatively treated for head and neck cancer. The participants will regularly take capsules containing broccoli seed powder to determine if they can tolerate the regimen and whether it has enough of an impact on their oral lining to prevent cancer. From there, larger clinical trials could be warranted.

“We call this ‘green chemoprevention,’ where simple seed preparations or plant extracts are used to prevent disease,” said Bauman. “Green chemoprevention requires less money and fewer resources than a traditional pharmaceutical study, and could be more easily disseminated in developing countries where head and neck cancer is a significant problem.”

Additional Pitt authors on this research were Yan Zhang, Malabika Sen, Daniel P. Normolle, Thomas W. Kensler, Sumita Trivedi and Siddharth H. Sheth; Jennifer R. Grandis, of Pitt at the time the study was conducted, and a Johns Hopkins researcher.

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Will anti-amyloid antibody prevent Alzheimer’s disease?

School of Medicine researchers will be part of a multicenter trial that will test for the first time whether a drug that treats brain plaques can prevent later development of memory loss in Alzheimer’s disease.

Studies have shown that brain changes in Alzheimer’s begin many years before disease onset, and that all patients have deposits of beta amyloid in their brains, said Oscar Lopez, neurology faculty member in the School of Medicine and codirector of the Alzheimer’s Disease Research Center. He is the principal investigator of the Pittsburgh arm of the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s (A4) study.

Said Lopez: “This is the first study to assess whether an experimental antibody that counteracts amyloid will have long-term impact that can prevent Alzheimer’s.” He noted that many people have beta amyloid deposits in the brain but never develop dementia. “We suspect that these plaques have a role in disease development, but it’s not been proven that they affect memory and cognition. The A4 study could shed light on that.”

For A4, the researchers will perform a baseline PET scan on otherwise healthy volunteers, ages 65-85, to determine if brain plaques are present. If so, participants will be assigned randomly to receive monthly intravenous infusions of the experimental anti-amyloid antibody or a placebo. All participants will have regular assessments and blood tests for three years.

“Because of the nature of the disease, a friend or family member also must be willing to answer questions annually about how the participant is doing at home,” Lopez explained. “This study could help us find ways of predicting who might be at greater risk for progressing to Alzheimer’s.”

Those interested in participating in the study should contact coordinator Katy Orchowski Zorich at 412/624-2730 or orchowskik3@upmc.edu.

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3 win awards for research papers

Three scientific papers published in 2014 by research teams from the School of Medicine and Children’s Hospital each have won a Clinical Research Forum Annual Top 10 Clinical Research Achievement Award.

The winning papers were chosen based on their degree of innovation from a pool of more than 50 nominations from 30 research and academic health centers nationwide. The papers chosen are believed to represent the best and brightest work in the field, and are expected to lead to advancements in medicine that will change lives and patient outcomes worldwide.

The three winners are:

• “Upper-Airway Stimulation for Obstructive Sleep Apnea,” published Jan. 9, 2014, in the New England Journal of Medicine (NEJM), showed implanting a device called Inspire Upper Airway Stimulation led to a 70 percent reduction of severe obstructive sleep apnea symptoms. Project investigators included lead author Patrick Strollo, faculty member in medicine and clinical and translational science and medical director of the UPMC Sleep Medicine Center, and Ryan Soose, Department of Otolaryngology faculty member.

• “A Randomized Trial of Protocol-Based Care for Early Septic Shock,” published May 1, 2014, in NEJM, showed that a structured, standardized approach to diagnose and treat sepsis in its early stages did not change patient survival rates. Project investigators included Derek Angus, faculty member, and Mitchell P. Fink, chair, Department of Critical Care Medicine, and Donald M. Yealy, chair of the Department of Emergency Medicine.

• “Antimicrobial Prophylaxis for Children With Vesicoureteral Reflux,” published June 19, 2014, in NEJM, showed that children with abnormal flow of urine from the bladder to the upper urinary tract, called vesicoureteral reflux (VUR), can avoid recurrent urinary tract infections by taking daily low-dose antibiotics.

Project investigators included senior author Alejandro Hoberman, pediatrics faculty member and chief, Division of General Academic Pediatrics at Children’s Hospital.

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Improving function after stroke

A technique that removes blood clots from large brain blood vessels reduced disability after stroke in a trial co-led by an expert from the School of Medicine. The findings of the study, conducted in Catalonia, Spain, were announced at the annual meeting of the European Stroke Organisation (EJO) and published online in NEJM.

The results of the trial, known as REVASCAT, echo findings from other recent large studies that were stopped early when the technique, called endovascular therapy or stent retriever thrombectomy, appeared to be highly effective, noted co-principal investigator Tudor Jovin, faculty member in neurology and neurological surgery and director of the UPMC Stroke Institute. Originally, the REVASCAT trial expected to enroll nearly 700 participants.

Said Jovin: “This is a giant step forward that will change the way we approach triage and treatment of stroke patients. After an interim analysis once 25 percent of the original participant sample size were enrolled, the data safety monitoring board of the study recommended stopping the trial as it became clear that it was no longer ethically justified to randomly assign patients to receive only conventional therapy. And, as other studies found, removing blood clots from the brain did indeed lead to better outcomes for patients.”

Endovascular therapy is performed by inserting a thin tube into a groin artery to thread it through the aorta and into the brain vessels using X-ray-guided imaging. A retrievable stent opens the blocked vessel to restore blood flow and then is withdrawn, pulling the clot out with it.

For the study, conducted at four large designated stroke centers in Catalonia November 2012-December 2014, the researchers treated and monitored 206 patients whose stroke symptoms began not more than eight hours earlier and who had evidence of vessel blockage in imaging studies. For the 70 percent of patients who received an intravenous dose of the clot-busting drug tPA, or alteplase, imaging studies conducted 30 minutes after tPA administration had to confirm the vessel was still blocked. Half the patients were assigned randomly to receive medical therapy alone and the other half to medical therapy plus stent retriever thrombectomy.

The researchers found a 1.7-fold reduction in disability and a 15.5 percent increase in the rate of return to functional independence in the endovascular therapy group compared to the medical intervention-alone group.

Because the Catalan Department of Health keeps a registry of all stroke patients treated with clot-busting therapies (intravenous or intra-arterial), the researchers were able to determine that nearly all eligible patients who were treated at participating centers and in Catalonia over the duration of the trial actually were enrolled in REVASCAT. This unique feature distinguished the trial from other similar recently published randomized studies, removing any lingering concerns that endovascular therapy for stroke is only beneficial for a minority of eligible patients, Jovin noted.

The researchers say that more work needs to be done to determine whether the technique is effective when performed more than eight hours after stroke onset, in vessels that are smaller and in different locations in the brain than those treated in REVASCAT, and in the very elderly.

Published the same day in the NEJM and presented at the EJO meeting, researchers announced further results of another large stroke trial of nearly 200 patients called SWIFT PRIME. That study showed endovascular treatment within six hours of stroke onset led to increased functional recovery and decreased 90-day disability. The Pitt arm of SWIFT PRIME, led by Jovin, was the second-leading enroller in the trial.

The REVASCAT study team included researchers from Barcelona; the University of Calgary, and the Dresden University of Technology.

The project was funded by the Fundació Ictus Malaltia Vascular through a grant from device manufacturer Covidien, and by a grant from the Spanish Ministry of Health cofinanced by FEDER (Instituto de Salud Carlos III).

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Grant to investigate iron deficiency

Vinayak Sant, faculty member in the pharmaceutical sciences department at the School of Pharmacy, has received a grant from North American Hoganas to develop color-masked iron powder.

The study’s objective is to evaluate the feasibility of masking the black color of ultrafine iron powder using food grade polymers without causing particle agglomeration. Another objective is to incorporate suitable additives with food grade polymers to enhance iron absorption.

Powdered iron is used widely to fortify various food products. However, the black color of iron powder restricts its use only in certain food products such as cereals, wheat flour, etc. If successful, the color-masked iron powder can be used in other food products such as rice, noodles, milk, yogurt, salt and sugar. This will help in reducing iron-deficiency anemia in various parts of the world.

According to the World Health Organization, 2 billion people — almost 30 percent of the world’s population — is anemic. Iron deficiency is the most common nutritional disorder causing anemia globally.

—Compiled by Marty Levine

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The University Times Research Notes column reports on funding awarded to Pitt researchers as well as findings arising from University research.

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