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Author: The Wistar Institute

RNA Editing Protein ADAR1 Protects Telomeres and Supports Proliferation in Cancer Cells

PHILADELPHIA — (March 12, 2021) — Scientists at The Wistar Institute identified a new function of ADAR1, a protein responsible for RNA editing, discovering that the ADAR1p110 isoform regulates genome stability at chromosome ends and is required for continued proliferation of cancer cells. These findings, reported in Nature Communications, reveal an additional oncogenic function of ADAR1 and reaffirm its potential as a therapeutic target in cancer.

The lab of Kazuko Nishikura, Ph.D., professor in the Gene Expression & Regulation Program of The Wistar Institute Cancer Center, was one of the first to discover ADAR1 in mammalian cells and to characterize the process of RNA editing and its multiple functions in the cell.

Similar to changing one or more letters in a written word, RNA editing allows cells to make discrete modifications to single nucleotides within an RNA molecule. This process can affect RNA metabolism and how it is translated into proteins and has implications for neurological and developmental disorders and antitumor immunity.

There are two forms of the ADAR1 protein, ADAR1p150 and ADAR1p110. While the RNA editing role of the former, located in the cytoplasm, has been extensively characterized, the function of the nuclear ADAR1p110 isoform remained elusive.

“We discovered that in the nucleus, ADAR1p110 oversees a similar mechanism to ADAR1p150, the better-known cytoplasmic variant, but the editing process in this case targets particular nucleic acid structures called R-loops when formed at the chromosome ends,” said Nishikura. “Through this function, ADAR1p110 seems to be essential for cancer cell proliferation.”

R-loops form during gene transcription when, instead of dissociating from its template DNA strand, the newly synthesized RNA remains attached to it, leading to a stable DNA/RNA hybrid. While these structures can be beneficial for transcriptional regulation in certain conditions, accumulation of R-loops can cause DNA damage, chromosome rearrangements and genomic instability and is linked to neurological disorders and cancer.

Nishikura and colleagues found that ADAR1p110 helps the cells resolve R-loops and prevent their accumulation by editing both the DNA and the RNA strands involved in the structure and facilitating degradation of the RNA strand by the RNase H2 enzyme.

Notably, researchers found that ADAR1p110 depletion results in accumulation of R-loops at the chromosome ends, indicating that ADAR1p110 acts on R-loops formed in the telomeric regions and is required to preserve telomere stability.

Telomeres serve as an internal clock that tells normal cells when it’s time to stop proliferating. Just like the plastic coating on the tips of shoelaces, telomeres protect chromosome ends from the loss of genetic material at each cell division, by their progressive shortening eventually triggers growth arrest or cell death.

Cancer cells bypass this mechanism to become immortal. Researchers found that ADAR1p110 depletion leads to extensive telomeric DNA damage and arrested proliferation specifically in cancer cells.

“It has recently been suggested ADAR1 inhibitors could potentiate tumor response to immunotherapy by interfering with certain cytoplasmic ADAR1p150 functions,” said Nishikura. “Based on our findings on the role of nuclear ADAR1p110 in maintaining telomere stability in cancer cells, we predict that ADAR1 inhibitors would be very effective anticancer therapeutics by interfering with two different and independent pro-oncogenic ADAR1functions exerted by the two isoforms.”

Co-authors: Yusuke Shiromoto*, Masayuki Sakurai*, Moeko Minakuchi*, and Kentaro Ariyoshi from The Wistar Institute. *Co-first authors.

Work supported by: National Institutes of Health (NIH) grants GM040536, CA175058, and GM130716; additional support was provided by the Emerson Collective, the Japan Society for the Promotion of Science (JSPS), and the Uehara Memorial Foundation. Core support for The Wistar Institute was provided by the Cancer Center Support Grant P30CA010815.

Publication information: ADAR1 RNA editing enzyme regulates R-loop formation and genome stability at telomeres in cancer cells, Nature Communications, 2021. Online publication.

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The Wistar Institute is an international leader in biomedical research with special expertise in cancer research and vaccine development. Founded in 1892 as the first independent nonprofit biomedical research institute in the United States, Wistar has held the prestigious Cancer Center designation from the National Cancer Institute since 1972. The Institute works actively to ensure that research advances move from the laboratory to the clinic as quickly as possible. wistar.org.

The First Basic Laboratory Cancer Center in the Nation

This year, the National Cancer Institute commemorates the 50th anniversary of the National Cancer Act, which changed the course of cancer research history in the U.S. In 1972, The Wistar Institute Cancer Center became the first Basic Laboratory Cancer Center in the nation.

By that time, cancer had become the second leading cause of death in the country, and President Nixon had declared a “war on cancer” and signed the National Cancer Act of 1971. A substantial part of the federal government’s support of this endeavor entailed providing funding to basic and translational research programs present on the territory with the designation of NCI Cancer Centers. Translating promising laboratory discoveries into new treatments, the NCI-designated cancer centers rapidly became the backbone of the NCI’s efforts for studying and controlling cancer.

With its leading-edge research and an international pool of top biologists on its faculty, Wistar entered the program at its onset. With support from a $3 million NCI grant and an additional $1.5 million raised by the Institute to build a new Cancer Research Building, Wistar made history becoming the first NCI-designated cancer center solely devoted to basic research. The Wistar Institute Cancer Center has been at the forefront of the field for almost half a century, investigating the causes underlying cancer while working to translate fundamental discoveries into cures.

A Look Back 

Under the scientific leadership of Wistar Director Hilary Koprowski, M.D., research at Wistar’s Cancer Center focused on the genetic alterations that take cells on the path of malignant transformation and the connection between viral infections and cancer, advancing new technologies for research and therapy.

It was the start of the DNA era, when scientists were beginning to unravel the genetic basis of cancer. Wistar researchers characterized some of the first chromosomal translocations, or genetic abnormalities caused by rearrangement of parts between chromosomes, responsible for causing lymphoma and leukemia. They also described how these rearrangements could break or alter the DNA sequence of oncogenes, leading to cancer.

Wistar scientists were among the first to pioneer monoclonal antibody technology, the first immunotherapy to be applied to cancer research. The Institute became a center of expertise in their production, quickly generating a large panel of antibodies for research and therapeutic purposes. The first clinical trial testing a monoclonal antibody for gastrointestinal cancer was conducted using a Wistar-generated antibody, and the first U.S. patent for monoclonal antibody technology was granted to Wistar. Monoclonal antibodies brought a revolution in tumor immunology and provided the basis for most of today’s targeted therapies and immunotherapies.

Armed with a deeper understanding of the role of genetic alterations in cancer and the ability to study and manipulate protein function with new technologies such as monoclonal antibodies, the field of cancer research moved forward to studying gene networks and signaling pathways. These pathways act in a highly orchestrated fashion so that changes in the function of one protein can affect a cascade of downstream events and drive tumor formation and spread. Wistar scientists focused especially on signaling pathways in breast cancer and melanoma.

One of the historic strengths of Wistar’s Cancer Center is structural biology — the study of the three-dimensional shape and structure of proteins, which informs how they function and interact with one another and with DNA. This type of investigation led to important advancements such as describing the physical structure of the enzyme that protects chromosome ends, called telomerase, and the creation of small chemical molecules that can fit into the functional pockets of target proteins and block their function.

The completion of the Human Genome Project in 2003 opened the post-genomic era. Scientists started to explore the concept that activity and function of genes is not solely determined by their DNA sequence. It was revealed that an additional important layer of regulation exists and orchestrates the dynamic interaction between genes and external stimuli. Wistar embraced this nascent field of study, called epigenetics and genome regulation, launching a new research program. Wistar scientists contributed critical discoveries, unveiling the role of new proteins and RNA in the regulation of gene expression.

The Cancer Center Today 

In recent years, Wistar has brought onboard a group of both early career and distinguished scientists to strengthen and expand its programs in the fields of tumor immunology and immunotherapy, cancer cell metabolism and plasticity, tumor microenvironment and cancer genomics.

Wistar cancer scientists work cooperatively and share their diverse array of skills to meet new scientific challenges. They are furthering the understanding of how tumor cells interact with and adapt to the surrounding environment to grow and spread; the intricate role of our immune system in cancer; how altered gene regulation can lead to malignancies and affect response to therapy; and how some viruses can cause cancer. Basic discoveries in these areas are informing the Cancer Center’s translational efforts for the early development of novel immunotherapies, targeted therapies and biomarkers, also thanks to a recently added medicinal chemistry expertise and a vibrant network of collaborations with academic institutions and the biotech industry. 

Learn more about the National Cancer Act and the 50th anniversary commemoration.

Rugang Zhang, Ph.D., Named the Christopher M. Davis Professor

Receiving an endowed professorship is a defining moment in a scientist’s career. Dr. Rugang Zhang has been named the Christopher M. Davis Professor and was honored at a virtual event that gathered together the Davis family and friends, colleagues, and past and present lab members to celebrate his prolific research career and the sustaining contributions of the Davis family.

“This endowed Christopher M. Davis Professorship is for the future of our research,” said Dario Altieri, M.D., Wistar president & CEO. “Today we celebrate Rugang and the Davis’ consistent support of the Institute. Their endowment is a tool for our faculty to become even bolder in how they think about science and more far reaching as they consider their research. It is the highest honor and the embodiment of the apex of impactful discovery science.”

Eleanor Davis and her husband, the late Harold (Hal) Davis, have been generous supporters of Wistar for more than four decades. Their philanthropy has resonated in the critical backing of scientists at the beginning of their scientific careers with the Christopher M. Davis Memorial Fellowship. Established in 1996 in memory of their son, it has funded 14 postdoctoral fellows since its inception. In 2013, thanks to the family’s generosity, the fellowship was transformed into the Christopher M. Davis Professorship, most recently bestowed on Dr. Zhang, to support established leaders doing high-impact research.

“How fortunate we are to have Christopher remembered this way — with science that makes other people’s lives better and longer,” said Eleanor Davis.

Dr. Karen Wylie, science officer for the Department of Defense (DoD) Ovarian Cancer Research Program, has worked with Dr. Zhang since 2010 when he received an early-career investigator award, and their collaboration continues with multiple active projects.

“We typically meet highly intelligent people in our line of work, but Rugang’s emotional intelligence matches his research accomplishments,” said Wylie. “Rugang has advanced discoveries, managed review panels, is a loving dad and husband, all the while carrying his high-energy style and genuine interest in inspiring his junior scientists to succeed. He stood out for being a real team player, always ready to focus beyond his needs.”

Dr. Zhang is deputy director of the The Wistar Institute Cancer Center and leader of its Immunology, Microenvironment and Metastasis Program. He joined Wistar in 2012 and studies the biology of clear cell ovarian cancer, one of the most lethal gynecological cancers in the world. His cutting-edge research focuses on identifying new targeted and combination therapies. Some of the strategies the Zhang lab discovered are now being tested in clinical trials.

Addressing the Davis family, Dr. Zhang said that their support and confidence inspires his team. “It is our turn to repay your generous investment in our research with impactful results,” he said. “In providing this support, you become partners in our quest for new knowledge and our effort to find cures for a disease that affects and touches the lives of so many of us.”

Dr. Zhang also acknowledged support from Ovarian Cancer Research Alliance and The Honorable Tina Brozman Foundation for Ovarian Cancer Research as instrumental in his professional development and the advancement of his research.

Ovarian Cancer Research Alliance, which granted him his first career development award in 2008 and currently supports the lab with a Collaborative Research Development Grant and mentored investigator awards to several postdocs, recently highlighted Dr. Zhang in a blog about his research, his personal story and the motivation that brought him into cancer research. Read the story here. 

Support That Runs Deep: Pennsylvania Breast Cancer Coalition Funding to Wistar Has Been a Bridge to New Discoveries

For almost 20 years, the Pennsylvania Breast Cancer Coalition (PBCC) has supported top Wistar researchers embarking on their scientific careers. For them, it has meant the opportunity to pursue scientific theories — no matter how off-the-beaten-track — and to investigate and make discoveries that could be transformative.

Wistar’s Dr. Zach Schug became the latest PBCC research grant winner. Funding has allowed him to study the complex role of acetate in cancer. He hopes to connect the dots between a high fat/high sugar diet, acetate metabolism, the gut microbiome, and gene expression to better understand how tumors eat, grow and progress in breast cancer.

PBCC founder Pat Halpin-Murphy and team came to Wistar for a heartfelt and socially distanced celebration and check presentation with Wistar’s president & CEO Dr. Dario Altieri and Dr. Schug.

“We are thrilled to focus our 2021 research grants funding on the treatments of tomorrow for patients with metastatic breast cancer,” said PBCC president and founder Pat Halpin-Murphy. “It is our hope that, with this research, scientists like Dr. Schug will find cures for patients whose disease has spread to advanced stages. Seeing these brilliant minds in action, and supporting their selfless work, is the motivation behind our mission of finding a cure for breast cancer now… so our daughters don’t have to.”

“We couldn’t do cutting-edge science without key funding from the PBCC, a local organization that has done so much for breast cancer research and care in our region,” said Dario Altieri, M.D., Wistar president and CEO, Cancer Center director and the Robert & Penny Fox Distinguished Professor. “We are fortunate to continue a long-standing partnership with the PBCC to advance the most innovative science and improve the lives of countless women with breast cancer.”

Out front of Wistar, the sun shone down on this special day, as the three discussed the shared opportunities and impact their organizations have made together.

Cheyney Celebrated 184th Anniversary and Recognized Wistar With the Institutional Partnership Award

Cheyney University President Aaron Walton recognized Wistar during their Founder’s Day, presenting the Institute with the Institutional Partnership Award. In February, the Wistar-Cheyney University Collaboration kicked-off with the very first group of Cheyney students taking part in a hands-on biomedical research curriculum with their sights set on internship and career opportunities in the region’s burgeoning life science sector.

The Cheyney University Founder’s Day event honored distinguished alumni, students, and staff with musical performances and presentations from the University community as well as political, sporting and artistic luminaries. It celebrated the legacy of all the torchbearers and leaders who contributed to Cheyney’s success in the face of insurmountable odds.

See the full video here. Wistar Partnership announcement starts at 00:41:00.

Reigniting Workforce Development Amidst the Pandemic

Wistar’s accelerated BTT Program means students can move into apprenticeships sooner to gain full time jobs.

The pandemic put the brakes on daily life, but didn’t stop scientific and educational progress at Wistar. With crucial funding from GSK through their STEM Equity Grant, the Institute can now fast-track Community College of Philadelphia pre-apprentices training in the Biomedical Technician Training (BTT) Program on to their next career phase as apprentices. 

BTT students in biomedical research labs at Wistar and biotech and pharmaceutical partners have received hands-on training reinforced with coursework in the classroom. But now, instead of completing the pre-apprenticeship over two summers, they can finish the program in just one. 

Through the accelerated BTT Program, students will be able to enter the Biomedical Research Technician (BRT) Apprenticeship faster and with a strong foundation in biomedical research skills that they can build upon during their apprenticeship. 

“With this support, we can continue to develop this program to the growing needs of our students and the life science sector, keeping the economic climate in mind,” said Kristy Shuda McGuire, Ph.D., Wistar associate dean of biomedical studies. “Through the BTT Program, students can do more than imagine a career in the life sciences. They can springboard into a laboratory position, where they can learn while they earn and contribute to important biomedical research.” 

Additional funding from a Pennsylvania Department of Labor & Industry PAsmart Grant is providing support to further expand and enhance the program, building on its 20 years of success training non-traditional students.

“Since 2000, Wistar has prepared trainees for jobs as laboratory technicians, research assistants, and beyond,” said William Wunner, Ph.D., Wistar director of outreach education, technology training and academic affairs. 

Dario Altieri, M.D., Wistar president and CEO, added, “The BTT Program has been a catalyst for new collaborative educational programs. It has showed us — as much as the students — how critical it is to engage in training and career development with the support of outstanding mentors. This, more than anything, is important to Wistar and our mission to prepare the next generation of scientists.”

A Virtual Glimpse Into Microscopic Life

Restrictions due to the COVID-19 pandemic didn’t stop Wistar from keeping up with a long-standing tradition that, for the past 18 years until this year, has brought hundreds of people to the Institute to marvel at the beauty of the microscopic world. Though this time it happened virtually.

We couldn’t open the Institute’s doors to host the Nikon Small World photomicrography competition and welcome visitors at the opening reception. Yet by the virtue of technology, we hosted a virtual conversation featuring the authors of three winning images from the 2020 competition and moderated by managing director of Wistar’s Imaging Facility James Hayden, a multiple-time Nikon Small World winner himself.

Daniel Castranova, a research specialist from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Jason Kirk, director of the Optical Imaging & Vital Microscopy core facility at Baylor College of Medicine, and Nadia Efimova, senior scientist at a Philadelphia-based pharmaceutical company, shared their passion for imaging, microscopy and photography and showed stunning images from their work. Wistar’s own postdoctoral researcher Irene Bertolini from the Altieri lab also presented her microscopy work that allows her to study the contribution of mitochondria in cancer.

Eric Flem, Nikon Instruments Inc. communications manager and curator of the competition, thanked Wistar for its partnership in showcasing the world’s largest photomicrography competition that includes a collection with thousands of entries from all over the globe each year.

Admiring remarkable details of zebrafish vasculature, intricate woven filaments within cells, and other intriguing features captured through the lens of a microscope and rendered as captivating works of art, the audience had a glimpse of the invisibly small world whose fascinating beauty is typically only revealed to scientists and microscopy pros.

Here’s to hoping that next year Wistar will welcome everyone back in person.

If you missed the event, please view the video below.

A Gene That Shields Our Skin From the Damages of UV Rays

Dr. Chengyu Liang, who joined the Wistar faculty in July 2020, leads an exciting research program that investigates fundamental cellular processes in the context of infectious disease  and cancer, with particular focus on melanoma. 

Her lab studies how a specific gene can protect our skin from the damage caused by ultraviolet (UV) radiation by examining the many functions of the UV radiation resistance associated gene (UVRAG).

Exposure to UV radiation from the sun is a major risk factor for the development of melanoma, as it leads to the accumulation of mutations in our cells. The Liang lab discovered that the UVRAG gene is responsible for promoting repair of the DNA damage caused by UV in skin cells.

Dr. Liang originally identified this gene as a promoter of autophagy — a natural mechanism cells use to digest, remove and recycle unwanted components. Her team then demonstrated UVRAG’s involvement in DNA damage repair and showed that melanoma patients with lower levels of UVRAG tend to have higher amounts of UV-associated mutations in their DNA. 

The team also discovered that UVRAG controls production of the melanin pigment in the skin, which provides a first-line protection against UV radiation and the risk of skin cancer.

The key role played by UVRAG in protecting our skin from UV-induced damage points to this gene as a tumor suppressor in melanoma and a new, promising prognostic and predictive biomarker. 

Further explore the work of the Liang lab in this article by Scientia.

Tom’s America

President Altieri remembers his late mentor Thomas Scott Edgington

Thomas Scott Edgington died in La Jolla, California, on January 22, 2021 from heart disease. He was a towering figure in vascular biology and a titan in molecular medicine with most of his career spent at the Scripps Research Institute in La Jolla, California. Tom contributed five decades of groundbreaking scientific advances, innovation and entrepreneurship: his work on tissue factor rewrote the narrative about coagulation in biology and medicine. Tom did not want an obituary. Maybe he thought that obituaries read as words in the past tense, abstract. In fact, Tom was never in the past tense or in the abstract. He was the present, in flesh and bones.

I was one of Tom’s postdoctoral fellows. I arrived at LAX on January 23, 1987 with the usual immigrant’s two suitcases. Two things I remember of that evening. A giant American flag hanging in the arrival hall and the pre-9/11 immigration officer who looked at my Italian passport and visa papers from Scripps and asked: What do you do for these guys? Research, I said. And research it was. Tom’s laboratory was an exhilarating forge of science and medicine around the clock. His passion was infectious, his dedication, inspiring and his hunger for knowledge, insatiable.

And yet, the Tom that stayed with me for thirty-five years was something else. His larger-than-life figure and the kaleidoscope of his lab taught me something else. As an immigrant, he taught me America. An America that was not just big cars, sheriffs and B52s. Tom was the living emblem of what that giant flag at LAX meant. Tom’s America was inclusive and welcoming. His laboratory had people of all walks of life, skin colors, religions and accents: everybody had a place. It never mattered where you came from. None of us attended the right schools or had the right connections (I doubt Tom even knew what a college legacy admission is). We were all self-starters and that’s exactly what Tom’s America loved: you are here now, he used to say, your merit is who you are.

Tom’s America was the stuff of movies and politicians: an America of chances, of opportunities. But Tom was no actor, and, believe me, he was no politician. That America truly lived in him and came to us. Unfiltered. In flesh and bones. We too could be who we were. Even if we spoke with an accent or never understood if the guy with the bat plays with or against the guy with the glove. Tom’s America was one of risk-taking, hard work and never give up. Not save anything for the swim back. Undaunted. The science was a microcosm of that America: if you did the experiment enough times and the controls are there, you go for it. But it’s against what people believe. Leave the word believe to religion, not science. And, so, Tom was never shy of standing his ground, of speaking his mind (and he always had a lot to say). Because there was always something joyous in that America anyway, where we take ourselves seriously, but not too seriously. Like when he showed us his 1960-era convertible saying that he had to buy that car back then to load up all the cheerleaders. And he laughed happily saying that.

It is not easy to say what we leave behind, what is our legacy. Maybe it’s the patients that we treated. Or the papers that we published, some of them will last, maybe. Tom left behind an ideal for us immigrants to see. He was not trying to convince anyone: just showing how he lived that ideal and how that ideal can live. So that we could learn from it. And perpetuate that America. At the symposium honoring his retirement from Scripps, Zaverio Ruggeri showed in his last slide how he saw Tom. It was a giant, millions of colors, Fourth of July firework. It could not have been more appropriate. And we, the immigrants, could not have been more grateful.

Dario C. Altieri, M.D.
President and CEO, The Wistar Institute
Director, The Wistar Institute Cancer Center
Philadelphia, PA 19106

Wistar Welcomes Cheyney University Students

On Feb. 4, Wistar welcomed eight students from Cheyney University that will take a Biomedical Research Methods course especially developed for their training as part of the Wistar-Cheyney collaboration launched to expand life science research education, training and business development opportunities in Pennsylvania.

In line with its tradition of training young scientists and preparing them for careers in the world of biomedical research, Wistar is a hub for students and trainees coming from different paths and at different stages of their education.

The Cheyney students are one of the latest additions to this community that will be the next generation of scientists, innovators and life science professionals in this region and beyond.

Click here to view Cheyney University’s press release