Pharmacologic suppression of MITF expression via HDAC inhibitors in the melanocyte lineage

• Published in: Pigment cell and melanoma research 2008-08, Vol.21 (4), p.457-463
• Main Authors: Yokoyama, Satoru, Feige, Erez, Poling, Laura L., Levy, Carmit, Widlund, Hans R., Khaled, Mehdi, Kung, Andrew L., Fisher, David E.
• Format: Article
• Language: English
• Subjects: Administration, Topical; Animals; Cell Lineage - drug effects; Cell Proliferation - drug effects; clear cell sarcoma; Down-Regulation - drug effects; Enzyme Inhibitors - administration & dosage; Enzyme Inhibitors - pharmacology; Gene Expression Regulation, Neoplastic - drug effects; HDAC inhibitor; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids - pharmacology; Indoles; Melanocytes - drug effects; Melanocytes - metabolism; melanoma; Melanoma - genetics; Melanoma - metabolism; Melanoma - pathology; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microphthalmia-Associated Transcription Factor - genetics; Microphthalmia-Associated Transcription Factor - metabolism; MITF; pigmentation; Sarcoma, Clear Cell - genetics; Sarcoma, Clear Cell - metabolism; Sarcoma, Clear Cell - pathology; Skin - drug effects; Skin Pigmentation - drug effects; Tumor Cells, Cultured
• ISSN: 1755-1471; 1755-148X
• DOI: 10.1111/j.1755-148X.2008.00480.x

Summary Melanoma incidence continues to rise at an alarming rate while effective systemic therapies remain very limited. Microphthalmia‐associated transcription factor (MITF) is required for development of melanocytes and is an amplified oncogene in a fraction of human melanomas. Microphthalmia‐associated transcription factor also plays an oncogenic role in human clear cell sarcomas, which typically exhibit melanoma‐like features. Although pharmacologic suppression of MITF is of potential interest in a variety of clinical settings, it is not known to contain intrinsic catalytic activity capable of direct small molecule inhibition. An alternative drug‐targeting strategy is to identify and interfere with lineage‐restricted mechanisms required for its expression. Here, we report that multiple histone deacetylase (HDAC)‐inhibitor drugs potently suppress MITF expression in melanocytes, melanoma and clear cell sarcoma cells. Although HDAC inhibitors may affect numerous cellular targets, we observed suppression of skin pigmentation by topical drug application as well as evidence of anti‐melanoma efficacy in vitro and in mouse xenografts. Consequently, HDAC inhibitor drugs are candidates to play therapeutic roles in targeting conditions affecting the melanocyte lineage.