Unlocking Nature’s Secrets: Sherry Gao Pushes the Boundaries of Genetic Engineering

by Ian Scheffler

Sherry (Xue) Gao, Presidental Penn Compact Associate Professor in Chemical and Biomolecular Engineering and in Bioengineering

Sherry (Xue) Gao, Presidential Penn Compact Associate Professor in Chemical and Biomolecular Engineering (CBE), always knew she had a future in the lab. “I grew up in China, and when I was little, maybe six or seven,” she recalls, “my teacher asked me, ‘What do you want to be when you grow up?’ I said, ‘I want to be a scientist!’”

Neither of her parents had studied beyond high school; when Gao finished her training as a chemical engineer, she became the first person in her family to graduate from college. “One of my greatest motivations is to help first-generation college students,” Gao says.

Now, as the newest faculty member in CBE, Gao is prepared to do just that: support the next generation of chemical engineers, while also conducting groundbreaking research in the development of small molecules to edit genes, pushing the boundaries of precision medicine.

The Presidential Penn Compact Professorships were created by former Penn President Amy Gutmann specifically to recruit and support faculty like Gao: transformative leaders working at the intersection of multiple fields with “a yen for collaboration,” as Gutmann told the Penn Gazette in 2021.

Gao joins Penn Engineering from Rice University, where she collected numerous accolades, including the 2024 BMES-CMBE Rising Star Award, a 2022 NSF CAREER Award, the 2022 Outstanding Young Faculty at Rice School of Engineering Award and the 2020 NIH MIRA R35 Award.

As a member of the Center for Precision Engineering for Health (CPE4H), Gao will partner with colleagues from across the School to develop technologies that bridge disciplines, all in the interest of advancing health care. “We are very excited to have Sherry as a new member of the Center,” says Daniel Hammer, Alfred G. and Meta A. Ennis Professor and inaugural Director of CPE4H. “Gene editing is an important new tool that can precisely alter cell behavior by deleting or redirecting cell pathways, as well as enhancing and suppressing gene expression. She will have significant interactions with other members of the Center, such as Mike Mitchell and myself, as well as the broader Penn community, especially with the CAR therapists.”

Read the full story in Penn Engineering Today.

Since this story was originally published in March 2024, Sherry Gao now holds a secondary appointment in Bioengineering, effective July 1, 2024.

Daniel Hammer and Michael Mitchell both hold primary appointments in Bioengineering.

From Chance to Certainty: Solving Science’s Reproducibility Crisis

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Jamie Moffa, host of In Plain English; Konrad Kording, Kaela Singleton and Arjun Raj

One of the pillars of science is the idea that experimental results can be replicated. If they cannot be reproduced, what if the findings of an experiment were due just to chance? Over the last two decades, a growing chorus of scientists has raised concerns about the “reproducibility crisis,” in which many published research findings can’t be independently validated, calling into question the rigor of contemporary science.

Two years ago, a group led by Konrad Kording, a Penn Integrates Knowledge Professor in Bioengineering and Neuroscience, founded the Community For Rigor (C4R) to build a grassroots movement to improve the rigor of scientific research.

Supported by a grant from the National Institutes of Health (NIH) and partners at Harvard, Duquesne, Smith College and Johns Hopkins, among other institutions, C4R creates educational materials that teach the principles of rigorous research, from data collection to pre-registration of results. “Everyone has done wrong things,” says Kording. “We’re all making these mistakes and we need to be able to talk about it.”

Last month, Kording appeared on In Plain English, a podcast devoted to making science more accessible, alongside Kaela Singleton, the co-founder and President of Black in Neuro; Arjun Raj, Professor in Bioengineering in Penn Engineering and in Genetics in Penn Medicine; and Jamie Moffa, a physician-scientist in training at Washington University in St. Louis, to discuss scientific rigor, including actionable strategies for students and faculty alike.

The conversation touched on everything from successfully managing the reams of data produced by experiments to the power of community to drive cultural change, as well as the difficulty of filtering useful feedback from the noise of social media. “I hope we can get to a point where people feel comfortable sharing what’s working and what’s not working,” says Raj.

Listen to the episode here.

Arjun Raj Explores Whether Cells Can Learn in 2024 Heilmeier Lecture

Arjun Raj (center) accepts the Heilmeier Award, with Bioengineering Department Chair Ravi Radhakrishnan (left) and Dean Vijay Kumar (right).

Arjun Raj, Professor in Bioengineering at Penn Engineering and in Genetics at the Perelman School of Medicine, has been honored with the 2023-24 George H. Heilmeier Faculty Award for Excellence for “pioneering the development and application of single-cell, cancer-fighting technologies.”

The George H. Heilmeier Faculty Award for Excellence in Research was “established by Penn Engineering for the purpose of recognizing excellence in scholarly activities of the faculty. Named in honor of George H. Heilmeier, it recognizes his extraordinary research career, his leadership in technical innovation and public service, and his loyal and steadfast support of Penn Engineering.”

Dr. Raj delivered his lecture, entitled “Can a Cell Learn?” on April 8, 2024. In this talk, Raj explores whether it is possible for cells to adapt to their environment by learning, thereby overcoming their genetic destiny.

Learn more about, this award, Dr. Raj and his research here. View the lecture recording below.

The Raj Lab for Systems Biology is interested in building a quantitative understanding of cellular function. They develop new tools for quantifying biological processes based on imaging and sequencing and then use those techniques to help us answer questions in molecular and cellular biology. Read more stories featuring Raj in the BE Blog.

Scientists Discover a Key Quality-Control Mechanism in DNA Replication

by Meagan Raeke

Illustration of the 55LCC complex. (Image: Courtesy of Cameron Baines/Phospho Biomedical Animation)

When cells in the human body divide, they must first make accurate copies of their DNA. The DNA replication exercise is one of the most important processes in all living organisms and is fraught with risks of mutation, which can lead to cell death or cancer. Now, findings from biologists from the Perelman School of Medicine and from the University of Leeds have identified a multiprotein “machine” in cells that helps govern the pausing or stopping of DNA replication to ensure its smooth progress. Illustration of the 55LCC complex. (Image: Courtesy of Cameron Baines/Phospho Biomedical Animation)

The discovery, published in Cell, advances the understanding of DNA replication, helps explain a puzzling set of genetic diseases, and could inform the development of future treatments for neurologic and developmental disorders.

“We’ve found what appears to be a critical quality-control mechanism in cells,” says senior co-corresponding author Roger Greenberg, the J. Samuel Staub, M.D. Professor in the department of Cancer Biology, director of the Penn Center for Genome Integrity, and director of basic science at the Basser Center for BRCA at Penn Medicine. “Trillions of cells in our body divide every single day, and this requires accurate replication of our genomes. Our work describes a new mechanism that regulates protein stability in replicating DNA. We now know a bit more about an important step in this complex biological process.”

Read the full story at Penn Medicine News.

Greenberg is a member of the Penn Bioengineering Graduate Group.

Arjun Raj Receives 2023-24 Heilmeier Award

by Olivia J. McMahon

Arjun Raj, Ph.D.

Arjun Raj, Professor in Bioengineering in Penn Engineering, has been named the recipient of the 2023-24 George H. Heilmeier Faculty Award for Excellence in Research for “pioneering the development and application of single-cell, cancer-fighting technologies.”

The Heilmeier Award honors a Penn Engineering faculty member whose work is scientifically meritorious and has high technological impact and visibility. It is named for the late George H. Heilmeier, a Penn Engineering alumnus and member of the School’s Board of Advisors, whose technological contributions include the development of liquid crystal displays and whose honors include the National Medal of Science and Kyoto Prize.

Raj, who also holds an appointment in Genetics in the Perelman School of Medicine, is a pioneer in the burgeoning field of single-cell engineering and biology. Powered by innovative techniques he has developed for molecular profiling of single cells, his scientific discoveries range from the molecular underpinnings of cellular variability to the behavior of single cells across biology, including in diseases such as cancer.

Raj will deliver the 2023-24 Heilmeier Lecture at Penn Engineering during the spring 2024 semester.

This story originally appeared in Penn Engineering Today.

Read more stories featuring Dr. Raj here.

“QR Code for Cancer Cells” – Uncovering Why Some Cells Become Resistant to Anti-Cancer Therapies

by Win Reynolds

QR codeA research team led by engineers at the University of Pennsylvania and Northwestern University scientists has created a new synthetic biology approach, or a “QR code for cancer cells,” to follow tumor cells over time, finding there are meaningful differences in why a cancer cell dies or survives in response to anti-cancer therapies.

Remarkably, what fate cancer cells choose after months of therapy is “entirely predictable” based on seemingly small, yet important, differences that appear even before treatment begins. The researchers also discovered the reason is not genetics, contrary to beliefs held in the field.

The findings were recently published in Nature.

The study outlined the team’s new technology platform that developed a QR code for each of the millions of cells for scientists to find and use later — much like tagging swans in a pond. The QR code directs researchers to a genome-wide molecular makeup of these cells and provides information about how they’ve reacted to cancer treatment.

“We think this work stands to really change how we think about therapy resistance,” said Arjun Raj, co-senior author and Professor in Bioengineering in the School of Engineering and Applied Science at the University of Pennsylvania. “Rather than drug-resistant cells coming in just one flavor, we show that even in highly controlled conditions, different ‘flavors’ can emerge, raising the possibility that each of these flavors may need to be treated individually.”

In the study, the lab and collaborators sought to apply synthetic biology tools to answer a key question in cancer research: What makes certain tumors come back a few months or years after therapy? In other words, could the lab understand what causes some rare cells to develop therapeutic resistance to a drug?

“There are many ways cells become different from each other,” said Yogesh Goyal, the co-senior author at Northwestern University. “Our lab asks, how do individual cells make decisions? Understanding this in the context of cancer is all the more exciting because there’s a clinically relevant dichotomy: A cell dies or becomes resistant when faced with therapies.”

Using the interdisciplinary team, the scientists put the before-and-after cloned cells through a whole genome sequencing pipeline to compare the populations and found no systematic underlying genetic mutations to investigate the hypothesis. Raj and Goyal  helped develop the QR code framework, FateMap, that could identify each unique cell that seemed to develop resistance to drug therapy. “Fate” refers to whether a cell dies or survives (and if so, how), and the scientists “map” the cells across their lifespan, prior to and following anti-cancer therapy. FateMap is the result of work from several research institutions, and it applies an amalgamation of concepts spanning several disciplines, including synthetic biology, genome engineering, bioinformatics, machine learning and thermodynamics.

“Some are different by chance — just as not all leaves on a tree look the same — but we wanted to determine if that matters,” Goyal said. “The cell biology field has a hard time defining if differences have meaning.”

Read the full story in Penn Engineering Today.

New Single Cell Analysis Tool

by Nathi Magubane

Researchers at Penn and colleagues have developed a tool to analyze single cells that assesses both the patterns of gene activation within a cell and which sibling cells shared a common progenitor.

3D illustration of a cell held by a pipet and a needle
Arjun Raj of the School of Engineering and Applied Science and the Perelman School of Medicine, former postdoc Lee Richman, now of Brigham and Women’s Hospital, and colleagues have developed a new analysis tool that combines a cell’s unique gene expression data with information about the cell’s origins. The method can be applied to identify new cell subsets throughout development and better understand drug resistance.

Recent advances in analyzing data at the single-cell level have helped biologists make great strides in uncovering new information about cells and their behaviors. One commonly used approach, known as clustering, allows scientists to group cells based on characteristics such as the unique patterns of active or inactive genes or by the progeny of duplicating cells, known as clones, over several generations.

Although single-cell clustering has led to many significant findings, for example, new cancer cell subsets or the way immature stem cells mature into “specialized” cells, researchers to this point had not been able to marry what they knew about gene-activation patterns with what they knew about clone lineages.

Now, research published in Cell Genomics led by University of Pennsylvania professor of bioengineering Arjun Raj has resulted in the development of ClonoCluster, an open-source tool that combines unique patterns of gene activation with clonal information. This produces hybrid cluster data that can quickly identify new cellular traits; that can then be used to better understand resistance to some cancer therapies.

“Before, these were independent modalities, where you would cluster the cells that express the same genes in one lot and cluster the others that share a common ancestor in another,” says Lee Richman, first paper author and a former postdoc in the Raj lab who is now at Brigham and Women’s Hospital in Boston. “What’s exciting is that this tool allows you to draw new lines around your clusters and explore their properties, which could help us identify new cell types, functions, and molecular pathways.”

Researchers in the Raj Lab use a technique known as barcoding to assign labels to cells they are interested in studying, particularly useful for tracking cells, clustering data based on cells’ offspring, and following lineages over time. Believing they could parse more valuable information out of this data by incorporating the cell’s unique patterns of gene activation, the researchers applied ClonoCluster to six experimental datasets that used barcoding to track dividing cells’ offspring. Specifically, they looked at the development of chemotherapy resistance and of stem cells into specialized tissue types.

Read the full story in Penn Today.

Spencer Haws Receives Druckenmiller Fellowship

Spencer Haws, Ph.D.

Spencer Haws, Postdoctoral Research Fellow in the laboratory of Jennifer E. Phillips-Cremins, Associate Professor and Dean’s Faculty Fellow in Bioengineering and in Genetics, was awarded a 2022 Druckenmiller Fellowship from the New York Stem Cell Foundation Research Institute (NYSCF). This prestigious program is the largest dedicated stem cell fellowship program in the world and was developed to train and support young scientists working on groundbreaking research in the field of stem cell research. Haws is one of only five inductees into the 2022 class of fellows.

Haws earned his Ph.D. in Nutritional Sciences in 2021 from the University of Wisconsin-Madison, where he studied metabolism-chromatin connections under the mentorship of John Denu, Professor in Biomolecular Chemistry at the University of Wisconsin-Madison. As a NYSCF – Druckenmiller Fellow in the Cremins Laboratory for Genome Architecture and Spatial Neurobiology, Haws is using this previously developed expertise to frame his investigations into the underlying mechanisms driving the neurodegenerative disorder fragile X syndrome (FXS). “Ultimately, I hope that this work will help guide the development of future FXS-specific therapeutics of which none currently exist,” says Haws.

Read the full list of 2022 Druckenmiller Fellows and view introductory videos on the NYSCF website.

Jennifer Phillips-Cremins Wins ISSCR Dr. Susan Lim Award for Outstanding Young Investigator

Jennifer Phillips-Cremins, Ph.D.

Jennifer E. Phillips-Cremins, Associate Professor and Dean’s Faculty Fellow in Bioengineering and Genetics, has been awarded the 2022 Dr. Susan Lim Award for Outstanding Young Investigator by the International Society for Stem Cell Research (ISSCR), the preeminent, global organization dedicated to stem cells research.

This award recognizes the exceptional achievements of an investigator in the early part of his or her independent career in stem cell research. Cremins works in the field of epigenetics, and is a pioneer in understanding how chromatin,  the substance within a chromosome, works:

“Dr. Phillips-Cremins is a gifted researcher with diverse skills across cell, molecular, and computational biology. She is a shining star in the stem cell field who has already made landmark contributions in bringing long-range chromatin folding mechanisms to stem cell research. In addition to her skills as an outstanding researcher,” ISSCR President Melissa Little, Ph.D., said. “She has flourished as an independent investigator, providing the stem cell field with unique and creative approaches that have facilitated conceptual leaps in our understanding of long-range spatial regulation of stem cell fate. Congratulations, Jennifer, on this prestigious honor.”

Cremins was awarded a NIH Director’s Pioneer Award in 2021 and a Chan Zuckerberg Initiative (CZI) grant as part of the CZI Collaborative Pairs Pilot Project in 2020. The long-term goal of her lab is to understand the mechanisms by which chromatin architecture governs genome function. The ISSCR will recognize Cremins and her research in a plenary session during the ISSCR annual meeting on June 15.

Read the full press release on the ISSCR website.

Yogesh Goyal Selected as 2021 STAT Wunderkind

Yogesh Goyal, Ph.D.

Yogesh Goyal, Ph.D.,  a postdoctoral researcher in Genetics and Bioengineering, has been selected as a 2021 STAT Wunderkind, which honors the “next generation of scientific superstars.” Goyal’s research is centered around developing novel mathematical and experimental frameworks to study how a rare subpopulation of cancer cells are able to survive drug therapy and develop resistance, resulting in relapse in patients. In particular, his work provides a view of different paths that single cancer cells take when becoming resistant, at unprecedented resolution and scale. This research aims to help devise novel therapeutic strategies to combat the challenge of drug resistance in cancer.

Goyal is a Jane Coffin Childs Postdoctoral Fellow in the systems biology lab of Arjun Raj, Professor in Bioengineering and Genetics at Penn. He will begin an appointment as Assistant Professor in the Department of Cell and Developmental Biology (CDB) in the Feinberg School of Medicine at Northwestern University in spring 2022.

Read the announcement in Penn Medicine News.