Analysis of ret gene rearrangements and forms in papillary thyroid carcinomas (PTC) of a Chinese population

Objective: To establish a method of detecting ret gene arrangements and to investigate the rearrangements and forms of ret oncogene in papillary thyroid carcinomas (PTC) of a Chinese population. Methods: RT-PCR was performed to detect the ret arrangements of paraffin-embedded specimens of 65 patients with PTC and the amplified products were cloned into T vector and sequenced using specific primers for ret/PTC 1, 2, 3 and 4. Result: RNA was successfully extracted from 38/65 cases, of which 71% were found expressing ret/PTC, including 10.5% PTC1, 5.3% PTC3 and 5.3% PTC4. The frequency of PTC1 was significantly higher than that of PTC2, which was found only in one patient. It was indicated that PTC in the Chinese population was related with ret rearrangements with H4 and ELE1. Previous studies also suggested that PTC1 and PTC3 occurred frequently in PTC patients. Conclusions: PTC1, 2, 3 and 4 forms are present in Chinese PTC patients, and PTC1 is more frequently found, consisting with other reports. Furthermore, multiple rearrangements could be present in a single specimen, with a frequency of 50% for all the detected cases. The present data suggest that the multiple rearrangements in a single specimen may be not linked to the degree of malignancy and metastasis