Expression and chromosomal assignment of PTPH1 gene encoding a cytosolic protein tyrosine phosphatase homologous to cytoskeletal-associated proteins

✍ Scribed by Fumio Itoh; Shigeo Ikuta; Yuji Hinoda; Yoshiaki Arimura; Mutsumi Ohe; Masaaki Adachi; Takeshi Ariyama; Johji Inazawa; Kohzoh Imai; Akira Yachi

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: French
• Weight: 642 KB
• Volume: 55
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910550612

✦ Synopsis

We have investigated the mRNA expression of 2 human protein tyrosine phosphatases with sequence homology to cytoskeletal proteins, PTPH I and PTPMEG. Northern-blot analysis of PTPHl 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. PTPHl 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, PTPH I mRNA became detectable, concomitant with the marked decrease in the expression level of c-myc mRNA. Moreover, the chromosomal localization of PTPH I gene was investigated by fluorescence in situ hybridization. Interestingly, PTPH I gene was mapped to 9q3 I where the gene for Gorlin syndrome, a putative tumor suppressor gene, exists.