Disease relevance of PTPRT

• The PTPRT mutation detected in the colon carcinoma was a missense mutation and the mutation in the gastric carcinomas was a splice-site mutation [1].
• However, because previously the mutational search has focused primarily on colon cancers, data on PTPRT mutations in other types of human cancer have largely been lacking [1].
• We detected PTPRT phosphatase domain mutations in 1 of 105 colon carcinomas (1%) and 1 of 48 gastric carcinomas (2%), but none in acute leukemias, hepatocellular carcinomas, breast carcinomas and non-small cell lung cancers [1].

High impact information on PTPRT

• Receptor protein tyrosine phosphatase rho (RPTPrho/PTPRT) is a transmembrane protein that is highly expressed in the developing and adult central nervous system [2].
• Furthermore, immunoprecipitation phosphatase assays indicated that E-cadherin, and to a far lesser extent p120(ctn), were tyrosine dephosphorylated by a recombinant RPTPrho intracellular fragment, and thus, were likely to be primary substrates for RPTPrho [2].
• The interaction of RPTPrho with adherens junctional components suggests that this phosphatase may transduce extracellular signals to the actin cytoskeleton and thereby play a role in regulating cadherin-mediated cell adhesion in the central nervous system [2].
• The RPTPrho gene was mapped to human chromosome 20 and mouse chromosome 2 [3].
• The motifs found in the extracellular segment of type II receptor protein tyrosine phosphatases are commonly found in neural cell adhesion molecules, suggesting that RPTPrho may be involved in both signal transduction and cellular adhesion in the central nervous system [3].

Biological context of PTPRT

• Five missense mutations in the most commonly altered PTP (PTPRT) were biochemically examined and found to reduce phosphatase activity [4].
• Expression of wild-type but not a mutant PTPRT in human cancer cells inhibited cell growth [4].
• An alternatively spliced mini-exon was identified in the extracellular segment of RPTPrho, between the fourth fibronectin type III repeat and the transmembrane domain [3].
• A recent report revealed that the protein-tyrosine phosphatase, receptor-type, T (PTPRT) gene is somatically mutated in several types of human cancer, suggesting that the mutated PTPRT gene is a tumor suppressor gene in human cancers [1].

Analytical, diagnostic and therapeutic context of PTPRT

• Northern blot analysis demonstrated that RPTPrho expression was restricted to the central nervous system, and in situ hybridization studies showed that the RPTPrho transcript was distributed throughout the murine brain and spinal cord [3].

References