Friday, October 28, 2011
During surgical removal of thyroid tissue suspicious for cancer, fast, reliable, and cost-effective techniques are needed to analyze the resected tissue for biomarkers—including BRAF V600E, is a molecular biomarker for papillary thyroid cancer (PTC)—that can confirm the presence and type of cancer cells. Researchers have developed a new, rapid method for direct detection of the BRAF V600E gene in thyroid tissue without the need to purify DNA from tumor cells—high resolution melting analysis (HRM).
In HRM analysis, a sample of the resected thyroid tissue is homogenized and the DNA-containing portion is collected and washed. Polymerase chain reaction (PCR), a targeted gene detection technique, is then used to identify the presence of the BRAF V600E gene in the tissue sample. This is achieved without having to purify or sequence the DNA.
Jun Hee Park and G. Park from Chosun University Hospital, Republic of Korea, have demonstrated that HRM is at least as effective as alternative methods that rely on purified DNA for intra-operative detection of the BRAF V600E biomarker, according to data presented today at the 81st Annual Meeting of the American Thyroid Association (ATA). Using HRM to analyze cancerous tissue from 96 patients, Park and Park obtained a positive result for BRAF V600E in 58 of 96 samples (60.4%). The same 96 samples were subjected to two other testing methods that both required DNA purification—DNAsequencing and restriction fragment length polymorphism (RFLP) analysis. These analytical methods yielded a positive BRAF V600E result in 46.8% and 61.5% of samples, respectively. In comparison to these two techniques, direct HRM produced comparable results, was economical, and was suitable for intra-operative use with results available within 50 minutes.
Source: American Thyroid Association