Lack of PTC gene (ret proto-oncogene rearrangement) in human thyroid tumors.
PTC gene, which is derived from the rearranged form of the ret proto-oncogene, was originally discovered in human thyroid papillary carcinomas. This gene has been thought to act as a tumorigenetic factor in thyroid carcinoma, although the action of PTC oncogene products is still unknown. To study the frequency of the PTC gene present in human thyroid carcinomas, we investigated four cell lines derived from thyroid carcinoma and 22 thyroid tumor tissue specimens. The reverse transcriptase-polymerase chain reaction (RT-PCR) method was performed to detect putative PTC mRNA. The presence of the PTC gene in genomic DNA was analyzed by Southern blot hybridization. PTC mRNA was detected by the RT-PCR method in only one papillary carcinoma cell line (TPC-1 cell). Southern gel analysis confirmed the rearrangement of the ret proto-oncogene in this cell line. In the other three cell lines and 22 tumor tissue specimens, however, neither the PTC gene or mRNA was detected. These results demonstrate that the prevalence of the PTC gene in thyroid tumor is low and may not be essential for human thyroid tumorigenesis. That our present results conflict with previous reports may be due to general differences in genetic background among races.
Namba
H
H
First Department of Internal Medicine, Nagasaki University School of Medicine, Japan.
Yamashita
S
S
Pei
H C
HC
Ishikawa
N
N
Villadolid
M C
MC
Tominaga
T
T
Kimura
H
H
Tsuruta
M
M
Yokoyama
N
N
Izumi
M
M
D001483:Base Sequence; D015139:Blotting, Southern; D002291:Carcinoma, Papillary / Q000737:chemistry / Q000235:genetics*; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D029721:Drosophila Proteins; D005784:Gene Amplification / Q000235:genetics; D015321:Gene Rearrangement / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000032:analysis / Q000235:genetics*; D051096:Proto-Oncogene Proteins c-ret; D011519:Proto-Oncogenes / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases; D013964:Thyroid Neoplasms / Q000737:chemistry / Q000235:genetics*; D014407:Tumor Cells, Cultured / Q000737:chemistry / Q000473:pathology
D004273:DNA, Neoplasm; D029721:Drosophila Proteins; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila