Ann S. Tsukamoto Weissman (born July 6, 1952) is an Asian American

stem cell In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell ...

researcher and inventor. In 1991, she co-patented a process that allowed the human stem cell to be isolated and demonstrated their potential in treating patients with

metastatic breast cancer Metastatic breast cancer, also referred to as metastases, advanced breast cancer, secondary tumors, secondaries or stage IV breast cancer, is a stage of breast cancer where the breast cancer cells have spread to distant sites beyond the axillary l ...

. Tsukamoto has received a total of 13 patents in her career, the majority of them having to do with human hematopoietic stem cells. Tsukamoto’s research and contributions in the medical field have led to groundbreaking advancements in stem cell research, especially in understanding the blood systems of cancer patients. Her work has shown potential treatments for

cancers Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

and

neurological disorders Neurological disorders represent a complex array of medical conditions that fundamentally disrupt the functioning of the nervous system. These Disorder of consciousness, disorders affect the brain, spinal cord, and nerve networks, presenting unique ...

, for which there were previously thought to be none.

Career

Ann Tsukamoto was born in California on July 6, 1952. She completed her bachelor's degree at the

University of California San Diego The University of California, San Diego (UC San Diego in communications material, formerly and colloquially UCSD) is a public university, public Land-grant university, land-grant research university in San Diego, California, United States. Es ...

and her Ph.D. in

immunology Immunology is a branch of biology and medicine that covers the study of Immune system, immune systems in all Organism, organisms. Immunology charts, measures, and contextualizes the Physiology, physiological functioning of the immune system in ...

and

microbiology Microbiology () is the branches of science, scientific study of microorganisms, those being of unicellular organism, unicellular (single-celled), multicellular organism, multicellular (consisting of complex cells), or non-cellular life, acellula ...

at the

University of California Los Angeles The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California, United States. Its academic roots were established in 1881 as a normal school then known as the southern branch of the Cal ...

. Tsukamoto did most of her postdoctoral work at the

University of California, San Francisco The University of California, San Francisco (UCSF) is a Public university, public Land-grant university, land-grant research university in San Francisco, California, United States. It is part of the University of California system and is dedic ...

. Here, she worked on the wnt-1 gene and developed a transgenic model for breast cancer. Wnt-1 was later discovered to be a key player in the stem cell self-renewal pathway. She joined the biotech company ''SyStemix'' from 1989 to 1997, where she co-discovered the human hematopoietic stem cell (hHSC) and played a leading role in the launch of the clinical research program for this cell. The purified hHSC was shown to be cancer-free when isolated from the cancer-contaminated hematopoietic mobilized blood of patients with disseminated cancer, and it successfully regenerated the patients' blood-forming system after myeloablative chemotherapy. Tsukamoto joined StemCells Inc. in 1998, where she has held several leadership roles overseeing the isolation and application of human neural and liver stem cells for various diseases. She led the scientific team that discovered the human central nervous system stem cell and identified a second candidate stem cell for the liver. Under her guidance, the human neural stem cell transitioned into early clinical development for all three components of the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

: the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

, and

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

. The biological potential and activity of these cells were demonstrated in some of the patients, mirroring the results observed in preclinical rodent studies. As of 2017, Tsukamoto is an inventor on seven issued United States patents, six of which are related to the human hematopoietic stem cell. By 2021, she had reached a total of 13 patents. Aside from her accomplishments in patent applications and grants, in 2023 she was awarded with the Changemaker Award from her alma mater (University of California San Diego) for her breakthrough in isolating blood stem cells. The work of Ann Tsukamoto has been of immense value to the field of regenerative medicine, particularly in the treatment and research of neurodegenerative diseases. Her research on human neural stem cells has resulted in potential therapeutic treatments for conditions such as spinal cord injury, Alzheimer's disease, and Parkinson's disease. Isolation of these stem cells has been a platform for further clinical research, testing their ability to repair and regenerate damaged neural tissues. Besides her contribution to hematopoietic and neural stem cell biology, her research and work has influenced advancements in gene therapy and tissue engineering, demonstrating the far-reaching nature of her scientific contribution. Apart from her research, Tsukamoto has also been a firm advocate for diversity in STEM, having mentored early-career researchers and lobbying for programs to integrate more women into the biotechnology industry. She has given talks regarding determination and collaboration in scientific inquiry, particularly among women and other minority groups within the discipline. Through public debate and mentorship initiatives, she continues to inspire upcoming generations of young female scientists to push beyond the limits of medical discovery. Her dedication to training the next generation of scientists, along with her groundbreaking and significant contributions to stem cell research, has ensured her place in the world as a biotechnology pioneer.

Patents

Out of her 13 patents, 7 were grants with 6 that revolved around human hematopoietic stem cells (October 1991-June 1999). The other grant being for methods of gene transfers (July 1999). The other 6 patents were applications, 4 on enriched pancreatic stem cell (September 2006-March 2011) and progenitor cell populations and 2 on genome editing of human neural stem cells using nucleases (October 2017-August 2023). Ann Tsukamoto’s work in stem cell research has had a profound impact on regenerative medicine. In 1989, while working at SyStemix, Inc., she co-discovered the human hematopoietic stem cell (hHSC), a major breakthrough in the field of hematopoiesis. Tsukamoto was among the co-inventors of the patent, Human Hematopoietic Stem Cell, which was granted on October 29, 1991. The patent detailed a process for isolating such cells, and has since become pivotal in the evolution of bone marrow transplant procedures for curing blood cancers and diseases. Up to 2021, Tsukamoto had acquired a total of 13 patents, six of which were specifically aimed at the human hematopoietic stem cell. The patents have played a significant role in the evolution of stem cell therapy for various blood-linked conditions, with new hope being provided to chemotherapy and other treatment-weakening patients' immune systems. In addition to her pioneering work in blood stem cells, Tsukamoto has also made significant contributions to the treatment of neurodegenerative disorders. During her time at StemCells, Inc., she was the leader of the team that first isolated human neural stem cells, which have therapeutic potential for the treatment of diseases like Alzheimer's, Parkinson's disease, and spinal cord injury. Her work has laid the foundation for ongoing clinical trials of stem cell-based therapies to treat central nervous system disorders. Tsukamoto's lab demonstrated that these cells have the ability to restore damaged tissue in preclinical models, laying the groundwork for future clinical uses in patients. Tsukamoto's extensive patent portfolio and progress in stem cell biology continue to shape the field of regenerative medicine. Her pioneering work as a hematopoietic and neural stem cell scientist continues to influence the field of regenerative medicine and inspire future researchers.

References

{{DEFAULTSORT:Tsukamoto, Ann Living people 20th-century American women scientists 21st-century American women scientists 1952 births Stem cell researchers 20th-century American biologists 21st-century American biologists American women biologists University of California, San Diego alumni University of California, Los Angeles alumni University of California, San Francisco alumni 21st-century American inventors American women inventors