DEVELOPMENT OF A SINGLE-STEP DUPLEX RT-PCR DETECTING DIFFERENT FORMS OF RET ACTIVATION, AND IDENTIFICATION OF THE 3RD FORM OF IN-VIVO RET ACTIVATION IN HUMAN PAPILLARY THYROID-CARCINOMA

In up to 25% of human papillary thyroid carcinomas (PCs), the oncogeni c activation of ret results from the fusion of its tyrosine kinase dom ain with different unlinked amino-terminal sequences. Activation of th is oncogene may be of prognostic significance in patients with PC. To screen for ret activation in archival paraffin-embedded tumors, we hav e developed a single-step duplex RT-PCR to detect different forms of r et activation despite different chimeric transcripts being expressed. Furthermore, we report a third type of ret oncogenic activation, named ret/PTC3, identified by using this novel method followed by rapid amp lification of cDNA ends (5'-RACE) cloning.