Public Release: 

Cloning reverses aging in cow cells, a milestone in medical research

Thomas Jefferson University

Vincent J. Cristofalo, Ph.D., president and CEO of the Lankenau Institute for Medical Research, and his colleague Mary Kay Francis, Ph.D., were among the investigators involved in an important cloning study that will be released later this week in the journal Science. In this report, the researchers described how they used a new cloning technique to rewind the aging clock in cells. The clock is considered to be the strand of DNA at the end of each chromosome (called telomeres), and is shortened every time a cell divides. When the aging clock runs out, the cells stop dividing.

Medical science has long sought to discover a "Fountain of Youth" that could potentially turn back the aging clock to return old cells to their earliest stages of development. If accomplished, this will have tremendous implications for regenerating cells and tissues in order to repair age-related damage. However, the results of previous research that resulted in Dolly the cloned sheep (created by a different cloning method) reported that she was actually aging faster and that her aging clock had not been reset.

The report in Science describes the cloning of six calves from old (senescent) cells at the end of their aging clock (lifespan). Cells taken from these animals not only show a return to a more youthful state, but they actually exhibited a longer lifespan. Cristofalo and Francis used multiple criteria from their expertise in studying changes that occur in the cellular aging process to confirm the age of the donor cells that Advanced Cell Technology, Inc. (ACT) used for its nuclear transfer experiments. ACT produced six healthy cloned calves from these donor senescent cells.

"The significance of this finding is that you can, in essence, reset the aging clock in animal cloning, a development which overturns a previous obstacle to effective cloning. The study establishes a basis for far more kinds of cloning experiments that could have significant implications in medicine and agriculture," said Cristofalo, who, in addition to leading the Lankenau Institute for Medical Research, is also a professor of pathology, anatomy and cell biology at Jefferson Medical College of Thomas Jefferson University in Philadelphia. He is internationally recognized for his research on the molecular mechanisms of cellular aging.

His work is based on findings that suggest that cellular aging is characterized by differential gene expression. Furthermore, Cristofalo's studies also show that the inability of senescent cells to synthesize DNA in response to growth factors (and thus divide again) is partially based on impaired signaling pathways between the sensing sites at the cell membrane and the targets in the nucleus.

Francis is an associate investigator at the Lankenau Institute for Medical Research and often collaborates with Cristofalo. Her research examines the mechanism of action of a particular protein that declines during cellular aging. She focuses on the role that the loss of this protein has in the development of diseases that afflict the elderly, such as tumor formation, wound-healing and chronic skin conditions. Francis is also an assistant professor of pathology, anatomy and cell biology at Jefferson Medical College.

The Lankenau Institute for Medical Research is a subsidiary of Main Line Health. It is located on the campus of Lankenau Hospital, located in suburban Philadelphia, in a state-of-the-art building where investigators concentrate on molecular, cellular and developmental biology specific to cancer, atherosclerosis, heart disease, osteoporosis, Alzheimer's disease and other diseases of aging.

"The theme of aging and the diseases of aging is a rare focus for a research center. Our ultimate goal is to determine the basis for the vulnerability to these diseases as we age, and to help people stay independent and productive during their lives, while reducing the impact of age-related diseases," said Cristofalo.


To arrange an interview with Cristofalo or Francis, please contact Laura Feragen at Toplin & Associates or call Susan Ahlborn at Main Line Health at 610-645-2180. To receive a copy of the Science article (#15), contact the News and Information Office at the American Association for the Advancement of Science at 202-326-6440 or email

Main Line Health, formed in January 1985, consists of three acute care hospitals, Bryn Mawr, Lankenau and Paoli Memorial; Bryn Mawr Rehab; Main Line Clinical Laboratories; Great Valley Health, a primary care network; the Wayne Center, a skilled nursing facility; and Mid County Senior Services. The mission of Main Line Health is to provide a comprehensive range of health services, complemented by appropriate educational and research activities, that meets community needs and improves the quality of life in the communities we serve.

The Jefferson Health System (JHS), formed in 1996, now includes Bryn Mawr Hospital, Lankenau Hospital, Paoli Memorial Hospital, Thomas Jefferson University Hospital (TJUH), and Methodist Hospital Division of TJUH; Bryn Mawr Rehab for physical medicine and rehabilitation; Jefferson HealthCARE Physicians, a primary care network that includes such organizations as Great Valley Health in the Main Line area; JeffCARE, a Physician Hospital Organization; Jefferson Home Care, Albert Einstein Medical Center, Germantown Community Health Services, MossRehab, Willowcrest (a center for subacute care), Willow Terrace at Germantown (a long-term care facility), and Belmont Behavioral Health. Einstein also operates a number of outpatient and satellite locations and a primary care network, Einstein Neighborhood Healthcare. Frankford Hospital includes three community teaching hospitals, the Frankford, Torresdale and Bucks campuses; three additional outpatient sites, and Frankford Health Care Network Physician Services. Magee Rehabilitation Hospital completes the group.


Cloning Reverses Aging in Cow Cells Science Journal Article Describes Milestone in Medical Research

If you plan to cover the April 28 Science article entitled "Extension of Cell Life-Span and Telomere Length in Animals Cloned from Senescent Somatic Cells," you may want to interview the internationally known researcher on aging involved in the study.

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