Development of a single-step duplex RT-PCR detecting different forms of ret activation, and identification of the third form of in vivo ret activation in human papillary thyroid carcinoma.

In up to 25% of human papillary thyroid carcinomas (PCs), the oncogenic activation of ret results from the fusion of its tyrosine kinase domain with different unlinked amino-terminal sequences. Activation of this oncogene may be of prognostic significance in patients with PC. To screen for ret activation in archival paraffin-embedded tumors, we have developed a single-step duplex RT-PCR to detect different forms of ret 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 amplification of cDNA ends (5'-RACE) cloning.