The transcription factor ATF2 promotes melanoma metastasis by suppressing protein fucosylation.

Abstract

Melanoma is one of the most lethal skin cancers worldwide, primarily because of its propensity to metastasize. Thus, the elucidation of mechanisms that govern metastatic propensity is urgently needed. We found that protein kinase Cε (PKCε)-mediated activation of activating transcription factor 2 (ATF2) controls the migratory and invasive behaviors of melanoma cells. PKCε-dependent phosphorylation of ATF2 promoted its transcriptional repression of the gene encoding fucokinase (FUK), which mediates the fucose salvage pathway and thus global cellular protein fucosylation. In primary melanocytes and cell lines representing early-stage melanoma, the abundance of PKCε-phosphorylated ATF2 was low, thereby enabling the expression of FUK and cellular protein fucosylation, which promoted cellular adhesion and reduced motility. In contrast, increased expression of the gene encoding PKCε and abundance of phosphorylated, transcriptionally active ATF2 were observed in advanced-stage melanomas and correlated with decreased FUK expression, decreased cellular protein fucosylation, attenuated cell adhesion, and increased cell motility. Restoring fucosylation in mice either by dietary fucose supplementation or by genetic manipulation of murine Fuk expression attenuated primary melanoma growth, increased the number of intratumoral natural killer cells, and decreased distal metastasis in murine isograft models. Tumor microarray analysis of human melanoma specimens confirmed reduced fucosylation in metastatic tumors and a better prognosis for primary melanomas that had high abundance of fucosylation. Thus, inhibiting PKCε or ATF2 or increasing protein fucosylation in tumor cells may improve clinical outcome in melanoma patients.

• Authors: Eric Lau, Yongmei Feng, Giuseppina Claps, Michiko N Fukuda, Ally Perlina, Dylan Donn, Lucia Jilaveanu, Harriet Kluger, Hudson H Freeze, Ze'ev A Ronai
• Journal: Science signaling (Sci Signal) Vol. 8 Issue 406 Pg. ra124 (Dec 08 2015) ISSN: 1937-9145 [Electronic] United States
• PMID: 26645581 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015, American Association for the Advancement of Science.

Chemical References

• ATF2 protein, human
• Activating Transcription Factor 2
• Atf2 protein, mouse
• Neoplasm Proteins
• Fucose
• Phosphotransferases (Alcohol Group Acceptor)
• fucokinase

Topics

• Activating Transcription Factor 2 (genetics, metabolism)
• Animals
• Cell Line, Tumor
• Fucose (genetics, metabolism)
• Glycosylation
• Humans
• Melanocytes (metabolism, pathology)
• Melanoma (genetics, metabolism, pathology)
• Mice
• Neoplasm Metastasis
• Neoplasm Proteins (genetics, metabolism)
• Phosphotransferases (Alcohol Group Acceptor) (genetics, metabolism)