 |
Aug. 22, 2001 |
||||||
|
Browse Archives
n Lung n Breast n General n Prostate n Leukemia n Lymphoma n Skin Cancer n Colon n Cervical/Uteri n Ovarian n Pancreatic n News/Issues |
Tracking down the DNA fingerprint of prostate cancer ANN ARBOR, MICH. - Aug. 23, 2001 (Cancer Digest) -- Like most killers, prostate cancer leaves fingerprints. Every malignant cell has a unique pattern of active and inactive genes and proteins that marks the difference between benign, localized or metastatic tumors. Hidden in this molecular profile are answers to questions doctors hear every day: Is surgery really necessary? Can I afford to wait? Will the cancer come back? Until recently, physicians have been unable to detect, let alone decode these fingerprints, which hold the key to understanding the relationship between gene expression and prognosis for men with prostate cancer. But in a new study published in tomorrow's issue of Nature, co-author Dr. Mark Rubin and colleagues from the University of Michigan Medical School examined the genetic and molecular profile of prostate cancer. "Our study has important applications in the diagnosis, prognosis and treatment of prostate cancer," says Rubin in a prepared statement. "The ultimate goal is to help physicians determine which patients need immediate, aggressive treatment and which can be watched and treated conservatively," says Rubin, an associate professor of pathology and urology in the U-M Medical School. The researchers analyzed 700 prostate tissue samples from 50 men using a relatively new technology, called DNA microarrays, that allows scientists to analyze thousands of genes simultaneously. They found nearly 200 genes or gene fragments in which the pattern of active and inactive genes varied consistently depending on whether the tissue was normal or malignant. U-M researchers used the DNA microarrays to assess gene expression profiles in four types of tissue, normal prostate tissue from men with and without prostate cancer, tissue with benign changes, localized prostate cancer and aggressive cancer that had spread or metastasized to other organs. "Previous prostate cancer studies focused on one gene at a time," says Dr. Arul Chinnaiyan, an assistant professor of pathology in the U-M Medical School who directed the study. "Using microarray technology, we were able to look at thousands of genes in prostate cells simultaneously. This is important, because it is most likely that many genes are involved in the development and progression of prostate cancer - each controlling a different step in the process." While some of the genes identified in the study are well known to cancer researchers, many others have never before been associated with prostate cancer. Two of these new genes are hepsin and pim-1, which could turn out to be important new clinical biomarkers for prostate cancer, according to Rubin. The researchers found that the hepsin protein production reached highest levels in pre-cancerous tissue, and lowest levels were found in benign prostate tissue. While hepsin's exact function is still unknown, the U-M researchers suspect it plays a key role in establishment of tumors. Pim-1, a known cancer-causing gene, also was highly expressed in prostate cancer and the levels of hepsin and pim-1 protein both were associated with patient prognosis. The next step is determining the functional role for each gene identified in the study as having an association with prostate cancer. "It has been 15 years since the Prostate Specific Antigen (PSA) test became available in 1987," says Rubin. "This approach could give us many new diagnostic tests within three to five years. Eventually, it could lead to a diagnostic kit physicians could use to determine the best treatment and prognosis for their patients with prostate cancer." |
||||||
SUBSCRIBE
FREE