Receptor protein tyrosine phosphatases and cancer

Nikolaienko, Roman; Agyekum, Boadi; Bouyain, Samuel

doi:10.4161/cam.21242

Cited by 21 publications

(23 citation statements)

References 114 publications

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“…Receptor protein tyrosine phosphatases (RPTPs) are the class of PTPs that besides the tyrosine phosphatase domains possess CAM-like extracellular regions anchoring these proteins at cell membrane. Twenty-one RPTPs encoded by human genome play a role in variable cellular processes (4).…”

Section: Introductionmentioning

confidence: 99%

Downregulation of PTPRH (Sap-1) in colorectal tumors

Bujko

Kober

Statkiewicz

et al. 2017

International Journal of Oncology

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Tyrosine phosphorylation is one of the basic mechanisms for signal transduction in the cell. Receptors exhibiting tyrosine kinase activity are widely involved in carcinogenesis and are negatively regulated by receptor protein tyrosine phosphatases (RPTP). Genes encoding different RPTPs are affected by aberrant epigenetic regulation in cancer. PTPRH (SAP-1) has been previously described to be overexpressed in colorectal cancer (CRC) and classified as an oncogenic factor. Previous microarray-based mRNA expression comparison of colorectal adenomas (AD), CRC and normal mucosa samples (NM) demonstrated that PTPRH tumor expression is the most reduced of all RPTP genes. qRT-PCR validation revealed gene downregulation for CRC (7.6-fold-change; P<0.0001) and AD (3.4-fold-change; P<0.0001) compared to NM. This was confirmed by immunohistochemical staining of tumor and NM sections as pronounced decrease of protein expression was observed in CRCs compared to the corresponding normal tissue. DNA methylation of two PTPRH promoter fragments was analyzed by pyrosequencing in a group of CRC, and AD patients as well as NM samples and CRC cell lines. The mean DNA methylation levels of these two regions were significantly higher in CRC than in NM. Both regions were highly methylated in SW480 and HCT116 cell lines contrary to unmethylated HT29 and COLO205. Cell lines with highly methylated promoters notably showed lower PTPRH expression levels, lower RNA II polymerase concentrations and higher levels of H3K27 trimethylation in the promoter and gene body, measured by chromatin immunoprecipitation. Cells were cultured with 5-aza-deoxycitidine and an increase in PTPRH expression was observed in SW480 and HCT116, whereas this was unchanged in the unmethylated cell lines. The results indicate that PTPRH is downregulated in colorectal tumors and its expression is epigenetically regulated via DNA methylation and chromatin modifications.

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Section: Introductionmentioning

confidence: 99%

Downregulation of PTPRH (Sap-1) in colorectal tumors

Bujko

Kober

Statkiewicz

et al. 2017

International Journal of Oncology

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“…Most recently, they have been identified as playing a role in restricting regeneration after neuronal injury (Fry et al, 2010; Shen et al, 2009). Mutations in RPTPs are increasingly recognized as causes of human disease (Nikolaienko et al, 2012; Stewart et al, 2013; Xu and Fisher, 2012). Less understood is the role that they play in the normal adult nervous system.…”

Section: Introductionmentioning

confidence: 99%

Receptor protein tyrosine phosphatase σ binds to neurons in the adult mouse brain

Katagiri

Lourie

et al. 2014

Experimental Neurology

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The role of type IIA receptor protein tyrosine phosphatases (RPTPs), which includes LAR, RPTPσ and RPTPδ, in the nervous system is becoming increasingly recognized. Evidence supports a significant role for these RPTPs during the development of the nervous system as well as after injury, and mutations in RPTPs are associated with human disease. However, a major open question is the nature of the ligands that interact with type IIA RPTPs in the adult brain. Candidates include several different proteins as well as the glycosaminoglycan chains of proteoglycans. In order to investigate this problem, we used a receptor affinity probe assay with RPTPσ-AP fusion proteins on sections of adult mouse brain and to cultured neurons. Our results demonstrate that the major binding sites for RPTPσ in adult mouse brain are on neurons and are not proteoglycan GAG chains, as RPTPσ binding overlaps with the neuronal marker NeuN and was not significantly altered by treatments which eliminate chondroitin sulfate, heparan sulfate, or both. We also demonstrate no overlap of binding of RPTPσ with perineuronal nets, and a unique modulation of RPTPσ binding to brain by divalent cations. Our data therefore point to neuronal proteins, rather than CSPGs, as being the ligands for RPTPσ in the adult, uninjured brain.

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“…Comprehensive reviews also exist on PTPs in human cancer [5] and the involvement of lipid-phosphatases in human disease [6]. RPTPs and the biological insight uncovered by the solution of several RPTP crystal structures have also been topics of discussion [7, 8]. We direct the reader to these sources for more comprehensive discussions since this review will focus largely on the application of non-biased screens as a discovery tool for PTP function.…”

Section: Introductionmentioning

confidence: 99%

Mining the function of protein tyrosine phosphatases in health and disease

Lee

Lawan

et al. 2015

Seminars in Cell & Developmental Biology

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Protein tyrosine phosphatases (PTPs) play a crucial role in the regulation of human health and it is now clear that PTP dysfunction is causal to a variety of human diseases. Research in the PTP field has accelerated dramatically over the last decade fueled by cutting-edge technologies in genomic and proteomic techniques. This system-wide non-biased approach when applied to the discovery of PTP function has led to the elucidation of new and unanticipated roles for the PTPs. These discoveries, driven by genomic and proteomic approaches, have uncovered novel PTP findings that range from those that describe fundamental cell signaling mechanisms to implications for PTPs as novel therapeutic targets for the treatment of human disease. This review will discuss how new PTP functions have been uncovered through studies that have utilized genomic and proteomic technologies and strategies.

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Receptor protein tyrosine phosphatases and cancer

Cited by 21 publications

References 114 publications

Downregulation of PTPRH (Sap-1) in colorectal tumors

Downregulation of PTPRH (Sap-1) in colorectal tumors

Receptor protein tyrosine phosphatase σ binds to neurons in the adult mouse brain

Mining the function of protein tyrosine phosphatases in health and disease

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