Sun Gang, Professor of Reproductive Medicine, Director of the Reproductive Medicine Center at Renji Hospital, and Deputy Director of the Shanghai Key Laboratory of Assisted Reproduction and Eugenics

Introduction:

From a young age, he was driven by a passion for biology, a field he views with both reverence and hope. Throughout his career, he has sought not only to accumulate knowledge but also to unravel the mysteries of life sciences. For him, biology is the foundation of life itself, where every cell is a critical component and every species a natural treasure. His journey, from China to abroad and from military service to civilian work, has been dedicated to advancing placental endocrinology research in his home country. After joining Renji Hospital, he and his colleagues at the Reproductive Medicine Center spent a decade transforming it into a leading program in Shanghai and across the nation. Today, he continues to mentor the next generation of scientists, leading by example as he pursues innovative research to safeguard the health of mothers and their babies.

The Path to Medicine

In the late 1970s, as a high school student, Sun Gang developed a profound interest in the life sciences. He devoured the limited popular science books available at the time, fueling his curiosity about the secrets of life. The black-and-white illustrations of plants and animals sparked his imagination, and from that moment, he was determined to pursue a career in medicine. He dreamed of one day working in a university lab, using a microscope to explore the world of cells and connect with the life sciences on a deeper level.

In 1979, Sun Gang was admitted to Shandong Medical College (now part of Shandong University) with outstanding results. He recalls the significance of that time: “1979 was the third year after the reinstatement the National College Entrance Examination, a policy shift that gave me this opportunity. China was recovering from the Cultural Revolution and faced a shortage of talent. To address this, our college established a six-year English-language medical program to train future educators. From an initial pool of 400, only 34 of us were selected for this track, which was taught in both Chinese and English, often by foreign experts.” This unique education not only provided a solid foundation for his medical career but also gave him the English proficiency to engage with international research.

After years of rigorous study and clinical practice, Sun Gang’s desire to understand the mechanisms of disease led him to pursue postgraduate studies. “I chose human physiology because it is the fundamental science of how the body functions. I believe you must understand normal life to decipher disease, and ultimately, to alleviate patient suffering,” he explained. He set his sights on the Second Military Medical University in Shanghai, home to the nation’s top physiology professors.

There, Sun Gang met his mentor, Professor Zhu Henian, a towering figure in Chinese medicine and a leading authority in physiology and neuroscience. After the Cultural Revolution, Professor Zhu had revitalized the department, pioneering research on acupuncture anesthesia and advocating for the study of neuroendocrinology. “As his student, I witnessed his rigorous approach to science and his immense sense of responsibility. Even in his eighties, he led by example in the lab. His ability to build a renowned program with limited resources inspired my own work at Renji Hospital—it showed me the power of a mentor’s example.”

Thanks to his excellent academic performance, Sun Gang was fast-tracked into a combined master’s-doctoral program. He researched the role of neuroendocrine hormones in traumatic shock, publishing his findings in international journals like Cardiovascular Research and earning his doctorate in 1990.

He remained at the university as an instructor, but his ambition extended further. Recognizing that medical research in China lagged behind the West, he decided to study abroad to learn new methodologies and contribute more effectively to his country’s medical progress. In 1992, he arrived at the University of Newcastle in Australia, where he began his scientific career in placental endocrinology under the renowned expert Professor Roger Smith.

He later moved to the University of Toronto in Canada, collaborating with the internationally recognized reproductive physiologist Professor John Challis. Together, they were the first to discover that human fetal membranes express large amounts of the glucocorticoid-regenerating enzyme 11β-HSD, publishing their landmark findings in the Journal of Clinical Endocrinology & Metabolism in 1997. This paper, which has been cited over 230 times, sparked a question that would define his career: why are these enzymes so abundant in fetal membranes?

This question led him to focus on the placenta and fetal membranes. To share this knowledge with Chinese clinicians, he decided to write a monograph. “Placenta research in China was limited then,” he said. “I spent my spare time in libraries, gathering materials and organizing them into what would become the first comprehensive book on the placenta in China.”

In 1998, Sun Gang answered a call to return to his alma mater, the Second Military Medical University. He was promoted to Professor and appointed Director of the Department of Physiology, where he built a placental endocrinology lab from scratch. Soon after, he published Basic and Clinical Aspects of Placental Endocrinology, the first book of its kind in the country. “The placenta is a vital endocrine organ, and its hormonal dysfunction is linked to major pregnancy complications like hypertension, fetal growth restriction, and preterm birth,” he explained. “This book detailed those connections for doctors and researchers.” The monograph established his reputation within the Chinese medical community.

In 2004, Sun Gang transitioned from military to civilian life, recruited by Fudan University and later introduced to Shanghai Renji Hospital. This move marked a new chapter, offering him greater freedom to pursue his scientific goals and advance his groundbreaking research.

Advancing Reproductive Medicine at Renji Hospital

“Academician Chen Zijiang is a leading authority in reproductive medicine. At the time, he was establishing the Shanghai Key Laboratory of Assisted Reproduction and Eugenics at Renji Hospital, which provided a critical platform for the field’s development.”

In 2013, at the recommendation of Chen Zijiang, Renji Hospital recruited Sun Gang from Fudan University to help build this key laboratory for the Reproductive Medicine Center. The task meant starting entirely from scratch.

“This was a process of building from nothing. The early days were not easy, with incomplete equipment and limited resources. But we started from zero, took it step by step, and persevered. We established our research methods one by one, and now we have a mature laboratory with capabilities in reproductive endocrinology, cell biology, and molecular genetics. We also quickly trained the first cohort of medical doctors at the Renji Reproductive Medicine Center.”

Through the team’s collective effort, the Renji Reproductive Medicine Center has made a leap forward in the past decade, a transformation Sun Gang has witnessed firsthand.

“Before I came to Renji, the Department of Reproductive Medicine was very small, with only seven or eight people. Today, the Renji Reproductive Medicine Center is one of the most advanced in the country. We possess state-of-the-art equipment and technology, attracting outstanding talent from home and abroad, and have become a leader in the field. In the latest Fudan University Hospital Ranking, our center is ranked in the top tier nationally.”

In Sun Gang’s view, the center’s growth has not only advanced basic research but has also created a powerful synergy between the laboratory and clinical departments.

“In the past, we relied more on talent trained elsewhere. Today, the Renji Reproductive Medicine Center has created a virtuous cycle for talent development. Every year, our lab hosts many PhD students who conduct high-level research, injecting new vitality into our work and supplying talent to the wider industry. Clinical doctors bring real-world problems to our basic research teams for exploration, and this cross-disciplinary model further strengthens our training programs.”

As a result, the Reproductive Medicine Center at Renji Hospital plays a pivotal role in the discipline. As the only reproductive medicine center in Shanghai to rank in the national top ten, its research metrics are exceptionally high.

“If we were ranked solely on research, our position would be even higher. This model of integrating research with clinical practice not only drives the discipline forward but also continuously elevates the research capabilities of our clinicians, providing strong support for overcoming clinical bottlenecks and improving patient care. Our department director, Professor Sun Yun, has received honorary titles like ‘Shanghai Craftsman’ and ‘Leading Talent,’ and I am very proud, as the clinical team’s development is inseparable from the support of our basic research.”

Sun Gang believes that advances in basic research provide new treatments and technologies for clinical practice. By studying reproduction-related genes, cells, and molecules, his lab can develop more effective and safe reproductive medicine technologies, such as assisted reproduction, genetic diagnosis, and gene therapy. These innovations have significantly improved outcomes for reproductive health issues like infertility, offering more options and hope to patients.

Furthermore, progress in basic research provides a critical scientific foundation for clinical medicine. A deeper understanding of disease mechanisms allows clinicians to create more scientific, personalized treatment plans, achieving the goal of precision medicine. At the same time, basic research provides a reliable basis for clinical trials, promoting continuous improvement and innovation in practice.

Integrating Basic Research with Clinical Practice to Advance Medical Translation

“When I was conducting research in Canada, I discovered that the glucocorticoid-regenerating enzyme 11β-HSD1 was very interesting. I found that fetal membranes express large amounts of it, but its physiological significance was unclear. After returning to China, whether at the Military Medical University, Fudan University, or now at Renji Hospital, I have remained dedicated to studying this. The first SCI paper I published after my return, in Biology of Reproduction in 2002, was the first to discover a positive feedback mechanism for 11β-HSD1 expression in fetal membranes, leading to a significant increase in glucocorticoid regeneration during late pregnancy. Glucocorticoids are classic anti-inflammatory hormones that typically inhibit the synthesis of inflammatory mediators like prostaglandins (PG). Paradoxically, however, in fetal membranes, they promote prostaglandin synthesis. Since prostaglandins trigger uterine contractions and cervical maturation, they are key to initiating labor. Therefore, the glucocorticoids regenerated in fetal membranes likely participate in the onset of labor by promoting prostaglandin synthesis. Our subsequent work found that this paradoxical effect is not mediated by the classic anti-inflammatory pathway but by transcription factors like CREB, STAT3, and C/EBPδ.”

After joining Renji Hospital, Sun Gang’s team found inspiration in dermatology research. They learned that long-term use of glucocorticoid medications can damage skin connective tissue. This led them to hypothesize that glucocorticoids in fetal membranes might be related to the extracellular matrix remodeling that occurs during fetal membrane rupture. To test this, Sun Gang and his graduate students conducted a series of experiments. They found that the regenerated glucocorticoids promote the degradation of collagen in the fetal membranes and inhibit the activity of collagen cross-linking enzymes. This leads to the breakdown of connective tissue, a process that contributes to fetal membrane rupture—what is commonly known as a woman’s “water breaking.” Therefore, targeting this glucocorticoid regeneration process could offer new strategies for preventing premature rupture of membranes and preterm birth.

This discovery generated widespread interest in the obstetrics community.

In 2018, invited by Endocrine Reviews, the most authoritative journal in international endocrinology, Sun Gang’s team published a review summarizing their years of research. They proposed that 11β-HSD1 in fetal membranes could be a potential drug target for preventing preterm birth.

“The incidence of preterm birth in China is as high as 7%, with over one million premature infants born each year. Preterm birth is not only the leading cause of perinatal death but also carries a high risk of disability for surviving infants. However, because the mechanism for human labor is not fully understood, there is currently a lack of effective preventive measures, making our research profoundly significant. If drug intervention can regulate 11β-HSD1, we could reduce the occurrence of preterm birth and its severe consequences. This would open new avenues for prevention, provide better protection for millions of infants, and bring good news to pregnant women and their families.”

Educating and Nurturing Talent for the Future

“Talent selection and development are crucial for the department’s future. For this reason, I encourage our team to pursue research with a more open and rigorous mindset. The complexities of life are vast, and our understanding of its mechanisms remains limited. We need generations of scientists and doctors to continuously strive and explore.”

Sun Gang has a clear philosophy for mentoring students. He emphasizes that rigor and pragmatism are paramount. Most students trained at the Renji Reproductive Medicine Center adopt this serious and rigorous approach to scientific research. Every week, he holds meetings where students must present their data, and he meticulously checks its reliability, stressing that repeatability is key to ensuring scientific validity.

“I encourage students to master the literature more deeply than their supervisors through their own efforts. As young people, they should have the desire and confidence to become experts. Students need their own thoughts and ideas to make research more dynamic. The interaction between teacher and student is vital; true innovation only happens in an environment of active communication. I encourage them to have the ambition to surpass their mentors.”

Sun Gang believes that sound research is logically coherent, whereas flawed results often crumble under logical scrutiny. He stresses that young researchers must think rigorously and clearly, constantly checking and verifying their findings.

“As scientific researchers, when we identify a problem, we must actively trace it to its root cause and understand exactly what has happened. Only then can further research be meaningful.”

Today, Sun Gang serves as an associate editor or editorial board member for three academic journals. He finds that while being an editor is demanding, it is also incredibly rewarding.

“As an editor, I invest significant time reviewing manuscripts and deciding on revisions or rejection. This responsibility is, for me, a form of recognition from the academic community and an opportunity to contribute to the field. It also requires me to read extensively, which brings inspiration and hones my own academic judgment. Only editors with deep expertise can make sound decisions, ensuring a journal’s quality. This work also gives me a systematic view of the latest industry developments, which not only inspires my own research but also allows me to better advise my students—it’s a win-win situation,” he adds with a smile.

Today, the Reproductive Medicine Center he helped build drives clinical medicine forward through its basic research advancements. The achievements and innovations from his lab provide the theoretical, technical, and therapeutic support for clinical practice, improving doctors’ research capabilities and treatment outcomes. This close integration of basic and clinical work not only pushes medical science forward but also delivers better care to patients.

In fact, Sun Gang also holds a personal ambition: to republish his book, The Basics and Clinical Practice of Placental Endocrinology.

“It’s been over twenty years since the first edition,” he says. “In that time, technology has advanced tremendously, and our understanding of placental endocrinology has evolved. An updated version would be an invaluable resource for the medical community and clinicians in China.”

Looking to the future, Professor Sun Gang has even grander plans. He aims to further elevate the center’s influence by forging international collaborations to introduce cutting-edge medical concepts and technologies, continuously raising the center’s research and clinical standards. Concurrently, he hopes to cultivate a new generation of medical professionals equipped with a global vision and an innovative spirit to contribute to the nation’s medical progress.

Professor Sun Gang is confident that with ongoing technological advancements and in-depth research, reproductive medicine is poised for even greater breakthroughs. He looks forward to a future where more families can benefit from these scientific advancements and fulfill their dreams of having children. And as both a medical explorer and an educator, he remains dedicated to advancing on this path of hope and challenge.

Editor: Chen Qing @ ShanghaiDoctor.cn

If you'd like to contact Prof. Sun, please be free to let us know at chenqing@ShanghaiDoctor.cn. 

Note: Chinese Sources from “The Path of Benevolent Medicine” which was published in 2024. It records 90 important medical figures in the history of Renji Hospital. Yewen Renyi (ShanghaiDoctor.cn) team was one of the major writers of the book and is authorized by Renji hospital to create English version on the website of ShanghaiDoctor.cn