New technique for cancer screeningFebruary 24, 2009Graz, Austria - Current research suggests that a new technique to determine tumor methylation status can be used in archived tissue samples. The related report by Balic et al, "High quality assessment of DNA methylation in archival tissues from colorectal cancer patients using quantitative high-resolution melting analysis," appears in the March 2009 issue of The Journal of Molecular Diagnostics. DNA in tumors is often altered compared with DNA in normal tissues. One common DNA alteration in cancerous tissue is hypermethylation, which results in loss of gene expression. The difference in methylation between normal and cancerous tissues can be used as a biomarker for early cancer diagnosis, risk assessment, and response to therapy. Archival tissues, or tissues that are formalin-fixed and paraffin-embedded for long-term storage, are difficult to screen for cancer biomarkers due to the low quality of their DNA. It is therefore important to develop new techniques to screen for DNA methylation that can be used in archival tissues. Balic and colleagues examined the ability of high-resolution melting analysis (HRM) to detect methylation on archival tissues from colorectal cancer patients. They found that HRM provided similar results between archival and fresh tissues. In addition, they validated the results using the widely used MethyLight assay. The results by Balic et al "add substantial information on the HRM-based DNA methylation analysis and demonstrate its applicability for analysis of archival tissues." This assay can be used to establish risk stratification of patients based on methylation status of specific markers and, due to its high sensitivity may have the potential to detect low amounts of methylated cells within the tumor, or even to detect low numbers of tumor cells in the background of non-tumor cells in lymph nodes and other organs. Most importantly, because formalin fixation and paraffin embedding are the most common means of tissue storage, the reported method has the potential to make DNA methylation analysis possible on this vast tissue resource. Balic and colleagues will now evaluate the ability of HRM-based DNA methylation analysis to predict the presence of lymph node metastases and to detect very small tumor deposits in lymph nodes with known micrometastatic disease in a well defined cohort of prostate cancer samples. This may lead to new and better predictive and staging methods for prostate cancer patients. American Journal of Pathology |
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| Related Methylation Current Events and Methylation News Articles Researchers discover RNA repair system in bacteria In new papers appearing this month in Science and the Proceedings of the National Academy of Sciences, University of Illinois biochemistry professor Raven H. Huang and his colleagues describe the first RNA repair system to be discovered in bacteria. Genes signal late-stage laryngeal cancer, poorer outcome Researchers at Henry Ford Hospital have identified tumor-suppressing genes that may provide a more accurate diagnosis of disease stage and survival for laryngeal cancer patients than current standards. MDC scientists show how hematopoietic stem cell development is regulated During cell division, whether hematopoietic stem cells (HSCs) will develop into new stem cells (self-renewal) or differentiate into other blood cells depends on a chemical process called DNA methylation. Study finds 231 new genes associated with head and neck cancer A Henry Ford Hospital study has identified 231 new genes associated with head and neck cancer, one of the most deadly cancers responsible for 2.1 percent of all cancer deaths in the United States. New Approach for the Treatment of Malignant Brain Tumors Initial chemotherapy alone after surgery is just as successful as initial radiation therapy for patients from whom a very malignant brain tumor (anaplastic glioma) was removed. With this treatment, the patients survive on average > 30 months without a recurrence. New blood tests promise simple, cost-effective diagnosis of gastrointestinal cancers Promising results from two new blood tests that can aid in the early identification of patients with gastrointestinal (GI) cancers will be presented at Europe's largest cancer congress. Changes to DNA linked to diabetes Genes that regulate the energy consumption of cells have a different structure and expression in type II diabetics than they do in healthy people, according to a new study from the Swedish medical university Karolinska Institutet published in Cell Metabolism. Why don't brain tumors respond to medication? Malignant brain tumors often fail to respond to promising new medication. Researchers in Heidelberg have discovered a mechanism and a tumor marker for the development of this resistance. New DNA Test Uses Nanotechnology to Find Early Signs of Cancer Using tiny crystals called quantum dots, Johns Hopkins researchers have developed a highly sensitive test to look for DNA attachments that often are early warning signs of cancer. Researchers develop new, more-sensitive assay for detecting DNA methylation in colon cancer A study published in this week's online issue of Nature Biotechnology, demonstrates a unique and highly sensitive method for detecting methylation-associated cancers. More Methylation Current Events and Methylation News Articles |
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