96th Annual Meeting Anaheim, California April 16-20, 2005
Embargoed for Release at Time of Presentation: Tuesday, April 19, 2005 10:00 a.m. PDT Abstract: 6094
Contacts: Warren R. Froelich/AACR 215/440-9300, firstname.lastname@example.org Kellie Hanzak/Spectrum Science 202/955-6222, email@example.com In Anaheim: (4/16-4/20) Anaheim Convention Center (714) 765-2030
Biomarkers Isolated from Saliva Successfully Predict Oral and Breast Cancer
Anaheim, Calif. -- Screening for breast cancer and the early detection of other tumors one day may be as simple as spitting into a collection tube or cup, according to recent studies by UCLA researchers. In one early study based on a risk model, presented here at the 96th Annual Meeting of the American Association for Cancer Research, the UCLA scientists reported that genetic “biomarkers” isolated in saliva predicted oral squamous cell carcinoma in about nine out of 10 cases. A recent study by this group, published in Clinical Cancer Research, disclosed similar predictive powers for head and neck cancers. “These results indicate that such biomarkers found in saliva, called salivary transcriptomes, can be exploited for robust, high-throughput and reproducible tools for early disease detection,” said David T. Wong, professor and associate dean of research at the UCLA School of Dentistry and the Jonsson Comprehensive Cancer Center, the study’s senior investigator. “This is a proof-of-principal study, but our results will need to be validated in a larger sample size in a blinded manner,” he added. Also participating in the study were Yang Li, David Elashoff, MyungShin Oh, Stephanie Tsung and Mai N. Brooks at UCLA. Harvesting saliva and other bodily fluids for molecules that detect early cancers has long been a goal of scientists seeking quick and easy screening tools that could be done in a doctor’s office. The search for such tests, however, has been stalled until recently with the advance of several emerging technologies including improved methods to identify, collect, preserve and amplify genetic material and proteins.
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In this study, the UCLA team found they could isolate messenger RNA from saliva and blood sera that might have diagnostic value for detecting early cancer. In the cell, messenger RNA or mRNA carries a copy of the genetic code or DNA, housed in the cell’s nucleus, to other parts of the cell for protein manufacture. The process by which genes are copied to mRNA, via an enzyme called RNA polymerase, is called transcription and the products are called transcripts. The UCLA team collected saliva and blood from 32 patients with primary oral squamous cell carcinoma and 40 breast cancer patients, and matched each with saliva and blood from otherwise normal subjects. New techniques were developed to halt RNA degradation so the scientists could recover as much mRNA as possible for their samples. In all, the new techniques allowed the scientists to harvest up to 10,000 types of human mRNA from saliva, setting up a comparison test between cancer patients and the normal subjects based on analysis of their genetic “profiles.” “Both serum and saliva exhibited unique genetic profiles,” said Wong. “The risk model yielded a predictive power of 95 percent by using only the salivary transcriptome samples and 88 percent by using only serum transcriptome samples for oral squamous cell carcinomas,” said Wong. For oral cancer, salivary transcriptome has a slight edge of that of serum transcriptome analysis. Future research not only will involve a larger sample of cancer patients to refine prediction models, but also will include studies involving precancers and other difficult to detect cancers such as ovarian and pancreatic cancers. “One of the biggest hurdle that saliva is not a mainstream diagnostic fluid stems from the fact that saliva is not a darling fluid for researchers and clinician. To change that, we are defining the science of using saliva as a diagnostic fluid as well as user friendly clinical protocols that are consistent and reproducible, Our goal is to provide optimized and standardized protocols to assure consistent results. We have them now. The studies are supported by grants from the U.S. Public Health Service (National Institute of Dental & Craniofacial Research) and the UCLA Jonsson Comprehensive Cancer Center to David T. Wong. #### Founded in 1907, the American Association for Cancer Research is a professional society of more than 24,000 laboratory, translational, and clinical scientists engaged in all areas of cancer research in the United States and in more than 60 other countries. AACR's mission is to accelerate the prevention and cure of cancer through research, education, communication, and advocacy. Its principal activities include the publication of five major peer-reviewed scientific journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention. AACR's Annual Meetings attract more than 15,000 participants who share new and significant discoveries in the cancer field. Specialty meetings, held throughout the year, focus on the latest developments in all areas of cancer research.
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