Oncogene database

8073

PTP4A2

protein tyrosine phosphatase type IVA, member 2;PTP4A2;protein tyrosine phosphatase type IVA, member 2

PTP(CAAXII)|phosphatase of regenerating liver 2|protein tyrosine phosphatase IVA|protein tyrosine phosphatase IVA2|protein tyrosine phosphatase type IVA 2|protein-tyrosine phosphatase 4a2|protein-tyrosine phosphatase of regenerating liver 2

1p35

protein-coding

A PCR-based subtractive hybridisation technique was used to identify genes involved in stromal-epithelial interactions in prostate cancer. Eight genes were identified as being differentially expressed in benign prostatic fibroblast cells after stimulation with tumourigenic LNCaP conditioned media. One of these genes, protein tyrosine phosphatase CAAX2 (PTPCAAX2; also described as PTP4A and OV-1), has recently been shown to be oncogenic in hamster pancreatic epithelial cells. We show that PTPCAAX2 expression is up-regulated 4-fold in benign prostatic fibroblast cells 24 h after stimulation with LNCaP conditioned media and up-regulated 9-fold in prostatic tumour fibroblast cells. PTPCAAX2 overexpression was also detected in both androgen-dependent and androgen-independent prostate cancer cell lines and prostate tumour tissue, as determined by RT-PCR analysis and in situ hybridisation. These observations of PTPCAAX2 overexpression in prostate tumour cells and tissue suggest that PTPCAAX2 may potentially function as an oncogene in prostate cancer.

The phosphatases of regenerating liver (PRLs) are an intriguing family of dual specificity phosphatases due to their oncogenicity. The three members are small, single domain enzymes. We provide an overview of the phosphatases of regenerating liver, compare them to related phosphatases, and review recent reports about each phosphatase. Finally, we discuss similarities and differences between the phosphatases of regenerating liver, focusing on their molecular mechanisms and signalling pathways.