Expression and chromosomal assignment of PTPH1 gene encoding a cytosolic protein tyrosine phosphatase homologous to cytoskeletal-associated proteins.
We have investigated the mRNA expression of 2 human protein tyrosine phosphatases with sequence homology to cytoskeletal proteins, PTPH1 and PTPMEG. Northern-blot analysis of PTPH1 using poly (A)+ RNA from normal human colon tissue showed a low-abundance message of 4.3 kb. Reverse-transcriptase/polymerase-chain reaction (RT-PCR) was therefore used to detect it in a wide variety of cell lines including 9 colorectal, 5 gastric, 5 hepatic and 6 hematopoietic tumor cells. PTPH1 mRNA was not detected only in Colo 320 cells over-expressing c-myc mRNA, among the colorectal cancer cell lines examined. When Colo 320 cells were incubated with 5 mM sodium butyrate for 5 days, PTPH1 mRNA became detectable, concomitant with the marked decrease in the expression level of c-myc mRNA. Moreover, the chromosomal localization of PTPH1 gene was investigated by fluorescence in situ hybridization. Interestingly, PTPH1 gene was mapped to 9q31 where the gene for Gorlin syndrome, a putative tumor suppressor gene, exists.
Itoh
F
F
Department of Internal Medicine (Section 1), School of Medicine, Sapporo Medical University, Japan.
Ikuta
S
S
Hinoda
Y
Y
Arimura
Y
Y
Ohe
M
M
Adachi
M
M
Ariyama
T
T
Inazawa
J
J
Imai
K
K
Yachi
A
A
D001483:Base Sequence; D015152:Blotting, Northern; D002874:Chromosome Mapping; D002899:Chromosomes, Human, Pair 9; D003106:Colon / Q000737:chemistry; D003110:Colonic Neoplasms / Q000737:chemistry / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000032:analysis / Q000235:genetics*; D005260:Female; D006801:Humans; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000032:analysis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D054589:Protein Tyrosine Phosphatase, Non-Receptor Type 3; D017027:Protein Tyrosine Phosphatases; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D014407:Tumor Cells, Cultured
D003598:Cytoskeletal Proteins; D012333:RNA, Messenger; D010749:Phosphoprotein Phosphatases; C516656:PTPN3 protein, human; D054589:Protein Tyrosine Phosphatase, Non-Receptor Type 3; D017027:Protein Tyrosine Phosphatases