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M A Pierotti

Publications and source records attributed to M A Pierotti.

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Molecular characterization of RET/PTC3; a novel rearranged version of the RETproto-oncogene in a human thyroid papillary carcinoma.

The RET proto-oncogene encodes a transmembrane receptor of the tyrosine kinase family and has frequently been found activated in human thyroid carcinomas of the papillary subtype. In most cases the activation consisted of the fusion of its tyrosine-kinase domain with the 5'-terminal region of a gene designated H4 or D10S170. We have named the resulting H4/RET chimeric oncogene RET/PTC. Another activated form of the RET oncogene has subsequently been found in a thyroid carcinoma and is now referred to as RET/PTC2. Here we report the identification and cloning of a novel rearranged version of the RET oncogene in a human thyroid papillary carcinoma. In this case the tyrosine-kinase domain of RET was fused to a sequence 790 bp long belonging to a new gene that we have named RFG (RET Fused Gene). This novel chimeric oncogene has been designated RET/PTC3. In order to have more insights into the function of RFG we have completely cloned and sequenced its cDNA. RFG predicted amino-acid sequence does not have any significant homology to any already known genes and is ubiquitously expressed in human and mouse tissues. Finally we provide evidence indicating that the rearrangement leading to the generation of RET/PTC3 occurred in vivo in the original tumor DNA.

Amino Acid Sequence

Characterization of an inversion on the long arm of chromosome 10 juxtaposing D10S170 and RET and creating the oncogenic sequence RET/PTC.

RET/PTC is a transforming sequence created by the fusion of the tyrosine kinase domain of the RET protooncogene with the 5' end of the locus D10S170 designated by probe H4 and is frequently found activated in human papillary thyroid carcinomas. RET and D10S170 have been mapped to contiguous regions of the long arm of chromosome 10: q11.2 and q21, respectively. To identify the mechanism leading to the generation of the oncogenic sequence RET/PTC, a combined cytogenetic and molecular analysis of several cases of papillary thyroid carcinomas was done. In four cases the results indicated that these tumors had RET/PTC activation and a paracentric inversion of the long arm of chromosome 10, inv(10)(q11.2q21), with breakpoints coincident with the regions where RET and D10S170 are located. Therefore, a chromosome 10q inversion provides the structural basis for the D10S170-RET fusion that forms the hybrid transforming sequence RET/PTC.

Blotting, Southern

PTC is a novel rearranged form of the ret proto-oncogene and is frequently detected in vivo in human thyroid papillary carcinomas.

We recently detected a novel activated oncogene by transfection analysis on NIH 3T3 cells in five out of 20 primary human thyroid papillary carcinomas and in the available lymph node metastases. We designated this transforming gene PTC (for papillary thyroid carcinoma). Here we describe the molecular cloning and sequencing of the gene. The new oncogene resulted from the rearrangement of an unknown amino-terminal sequence to the tyrosine kinase domain of the ret proto-oncogene. This gene rearrangement was detected in all of the transfectants and in all of the original tumor DNAs, but not in normal DNA of the same patients, thus indicating that this genetic lesion occurred in vivo and is specific to somatic tumors. Moreover, the transcript coded for by the fused gene was detected in an additional PTC-positive human papillary carcinoma for which mRNA was available.

Amino Acid Sequence