Research article

The fatty acid binding protein 7 (FABP7) is involved in proliferation and invasion of melanoma cells

Ana Slipicevic¹ , Kjersti Jørgensen¹ , Martina Skrede¹ , Anne Katrine Ree Rosnes¹ , Gunhild Trøen¹ , Ben Davidson^1,2 and Vivi Ann Flørenes¹

¹Pathology Clinic, Rikshospitalet-Radiumhospitalet Medical Center, Montebello N-0310 Oslo, Norway

²Faculty Division Radiumhospitalet, Medical Faculty, University of Oslo, Oslo, Norway

author email corresponding author email

BMC Cancer 2008, 8:276doi:10.1186/1471-2407-8-276

Published:	30 September 2008

Abstract

Background

The molecular mechanisms underlying melanoma tumor development and progression are still not completely understood. One of the new candidates that emerged from a recent gene expression profiling study is fatty acid-binding protein 7 (FABP7), involved in lipid metabolism, gene regulation, cell growth and differentiation.

Methods

We studied the functional role of FABP7 in human melanoma cell lines and using immunohistochemistry analyzed its expression pattern and clinical role in 11 nevi, 149 primary melanomas and 68 metastases.

Results

FABP7 mRNA and protein level is down-regulated following treatment of melanoma cell lines with a PKC activator (PMA) or MEK1 inhibitor (PD98059). Down-regulation of FABP7 using siRNA decreased cell proliferation and invasion but did not affect apoptosis. In clinical specimens, FABP7 was expressed in 91% of nevi, 71% of primary melanomas and 70% of metastases, with a cytoplasmic and/or nuclear localization. FABP7 expression was associated with tumor thickness in superficial spreading melanoma (P = 0.021). In addition, we observed a trend for an association between FABP7 expression and Ki-67 score (P = 0.070) and shorter relapse-free survival (P = 0.069) in this group of patients.

Conclusion

Our data suggest that FABP7 can be regulated by PKC and the MAPK/ERK1/2 pathway through independent mechanisms in melanoma cell lines. Furthermore, FABP7 is involved in cell proliferation and invasion in vitro, and may be associated with tumor progression in melanoma.