December 5, 2006
If dentists were to compile a wish list for their practices, one that might make the top 15 would be a quick, easy-to-administer test that tells them rapidly and reliably whether a patient has oral cancer. Among the research now under way is work on the so-called “lab on a chip” for oral squamous cell carcinoma, or OSCC, the most common form of oral cancer. Roughly the size of a credit card, this fully integrated, non invasive chip includes an arrayed platform of individual genes whose expression patterns are strongly associated with OSCC. As envisioned, a dentist would apply a small amount of fluid from a patient’s mouth to the lab on a chip. The device then rapidly directs the sample over the platform and measures the exact levels of messenger RNA corresponding to each arrayed gene in the fluid. Messenger RNA, like a receipt, is a transcript that a specific gene has been expressed. Depending on whether the collective expression pattern of the various genes match or are similar to those known for a developing OSCC, dentists will have their answer.
While work progresses to integrate the various components of these microfluidic devices, scientists also now must settle on which genes to include in the array. In the October 15 issue of the journal Clinical Cancer Research, NIDCR grantees report that they have compiled a 25-gene array that looks like a good candidate. Testing 44 normal and OSCC samples, the scientists found their gene array correctly classified 42 samples, for an accuracy rate of over 87 percent. They also found that the array failed to predict other human tumors, showing its specificity for OSCC. The scientists now are following up their initial work with larger, prospective studies.