Microarray analysis of phosphatase gene expression in human melanoma

• Published in: British journal of dermatology (1951) Vol. 152; no. 5; pp. 925 - 930
• Main Authors: McArdle, L., Rafferty, M.M., Satyamoorthy, K., Maelandsmo, G.M., Dervan, P.A., Herlyn, M., Easty, D.J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-05-2005; Blackwell; Oxford University Press
• Subjects: Biological and medical sciences; Blotting, Northern; Dermatology; DNA, Complementary - genetics; DNA, Neoplasm - genetics; Down-Regulation; Humans; Medical sciences; Melanocytes - enzymology; melanoma; Melanoma - enzymology; Melanoma - genetics; Melanoma - secondary; Microarray Analysis - methods; protein tyrosine phosphatase; Protein Tyrosine Phosphatases - biosynthesis; Protein Tyrosine Phosphatases - genetics; signal transduction; Skin Neoplasms - enzymology; Skin Neoplasms - genetics; Tumor Cells, Cultured; Tumors of the skin and soft tissue. Premalignant lesions; Human; Skin disease; Enzyme; Dermatology; protein tyrosine phosphatase; Phosphoric monoester hydrolases; melanoma; Esterases; Malignant tumor; Gene expression; Signal transduction; Malignant melanoma; Hydrolases; Protein-tyrosine-phosphatase
• ISSN: 0007-0963; 1365-2133
• DOI: 10.1111/j.1365-2133.2005.06454.x

Summary
Background  Tyrosine phosphate is abnormally elevated in malignant melanoma, and this has been interpreted to reflect the activity of oncogenic protein tyrosine kinases. However, elevation may also arise due to decreased protein tyrosine phosphatase (PTP) expression.
Objectives  To survey phosphatase gene expression in melanoma cell lines, a benign naevus and normal melanocytes: we searched for downregulation of phosphatase gene expression in malignant cells that may indicate a role as melanoma suppressor genes.
Methods  Microarray analysis was used to compare gene expression for 133 phosphatase genes, comprising 39 PTPs, 16 dual‐specificity phosphatases (DSPs), 47 serine/threonine phosphatases and 31 acid/alkaline and lipid‐based phosphatases. Northern blotting analysis was used to study gene expression in human melanoma biopsies.
Results  There was decreased expression of four DSP genes (including PTEN); eight receptor PTP genes were downregulated in melanoma, among which were PTP‐KAPPA and PTP‐PI (consistent with our previous data). In addition, PTP‐RF/LAR was downregulated in 13 of 22 metastatic melanomas.
Conclusions  The expression of multiple PTP receptors is decreased in melanoma; this may be a mechanism which stimulates autonomous growth in advanced melanoma.