Encouraging results in pancreatic cancer research
Protein destroys tumor cells in animals, leaves normal cells unharmed
Researchers at SUNY Downstate Medical Center and the Brooklyn VA Hospital have found that when a human protein, PNC-28, is administered to pancreatic tumor cells in animals, the tumors are destroyed. The research was reported in the October 1st edition of the International Journal of Cancer.
Matthew R. Pincus, MD, PhD, professor of pathology at SUNY Downstate and chairman of pathology and laboratory medicine at the Brooklyn VA, said, "The results are very encouraging. PNC-28 may be an effective agent in treating cancers, especially if delivered directly to the tumor."
PNC-28 is a p53 peptide, a naturally occurring human protein known to suppress tumor growth. The researchers previously found that PNC-28 induces death of a variety of human tumor cell lines, including a pancreatic cancer cell line, while not harming healthy cells.
The research team has now given PNC-28 to laboratory animals to test its ability to block the growth of pancreatic cancer cells. When administered over a two-week period in the peritoneal cavities of mice containing simultaneously transplanted tumors, PNC-28 caused complete destruction of these tumors.
When delivered concurrently with tumor implantation, PNC-28 completely blocked tumor growth during the two-week period of administration and two weeks post-treatment, followed by weak tumor growth that leveled off at low tumor sizes.
In addition, according to Josef Michl, MD, associate professor of pathology at SUNY Downstate, "When administered from a site distant from the tumor, PNC-28 still caused a decrease in tumor size. This tumor growth was significantly slower than growth in the presence of a control peptide."
Dr. Pincus added that this peptide and its parent peptide, called PNC-27, are lethal to a wide variety of human cancer cells, besides pancreatic cancer, including colon, breast, cervical and bone (osteogenic sarcoma) cancers. These peptides kill cancer cells that do not even contain native p53 protein and therefore appear to have a wide applicability in treating a variety of human cancers.
The journal article, "PNC-28, a p53-derived peptide that is cytotoxic to cancer cells, blocks pancreatic cancer cell growth in vivo," is available from Dr. Pincus. An abstract is also available online at http://www3.interscience.wiley.com/cgi-bin/abstract/112610113/ABSTRACT.
The Brooklyn VA Hospital is formally known as the Brooklyn campus of the Veterans Administration New York Harbor Healthcare System. SUNY Downstate Medical Center is the only academic medical center in Brooklyn, Staten Island, or Queens, comprising a College of Medicine, Colleges of Nursing and Health Related Professions, a School of Graduate Studies, and University Hospital of Brooklyn.
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