SIRT1 regulates lamellipodium extension and migration of melanoma cells.
Melanoma is highly metastatic, but the mechanism of melanoma cell migration is still unclear. We found that melanoma cells expressed the nicotinamide adenine dinucleotide-dependent protein deacetylase SIRT1 in the cytoplasm. Cell membrane extension and migration of melanoma cells were inhibited by SIRT1 inhibitors or SIRT1 knockdown, whereas SIRT1 activators enhanced elongation of protrusion and cellular motility. In B16F1 cells, growth factor stimulation induced lamellipodium extension, a characteristic feature at the leading edge of migrating cells, and SIRT1 was found in the lamellipodium. SIRT1 inhibitor nicotinamide (NAM) or SIRT1 small interfering RNAs suppressed the lamellipodium extension by serum or platelet-derived growth factor (PDGF). The lamellipodium formation by dominant-active Rac1 was also inhibited by NAM, a SIRT1 inhibitor. NAM inhibited the accumulation of phosphorylated Akt at the submembrane by serum or PDGF. Using fluorescence resonance energy transfer, we found that NAM impaired PDGF-dependent increase in the phosphatidylinositol-3,4,5-trisphosphate level at the leading edge. NAM inhibited the abdominal metastasis of transplanted B16F1 melanoma cells in C57BL6/J mice and improved survival. Finally, SIRT1-knockdown B16F1 cells showed significantly reduced metastasis in transplanted mice compared with that in control B16F1 cells. These results indicate that SIRT1 inhibition is a strategy to suppress metastasis of melanoma cells.
Department of Pharmacology, Sapporo Medical University, Sapporo, Japan; Department of Dermatology, Sapporo Medical University, Sapporo, Japan.
Risa
R
Kunimoto
Department of Dermatology, Sapporo Medical University, Sapporo, Japan.
Kowichi
K
Jimbow
Department of Pharmacology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Japan.
Akihiko
A
Tanimura
Department of Pharmacology, Sapporo Medical University, Sapporo, Japan; Department of Dermatology, Sapporo Medical University, Sapporo, Japan.
Masahiro
M
Sato
Department of Pharmacology, Sapporo Medical University, Sapporo, Japan; Department of Dermatology, Sapporo Medical University, Sapporo, Japan.
Kouhei
K
Horimoto
Department of Pharmacology, Sapporo Medical University, Sapporo, Japan.
Takashi
T
Hayashi
Department of Pharmacology, Sapporo Medical University, Sapporo, Japan.
Shin
S
Hisahara
Department of Pharmacology, Sapporo Medical University, Sapporo, Japan.
Toshiya
T
Sugino
Radiation Risk Reduction Research Program, National Institute of Radiological Sciences, Chiba, Japan.
Tomohisa
T
Hirobe
Department of Dermatology, Sapporo Medical University, Sapporo, Japan.
Toshiharu
T
Yamashita
Department of Pharmacology, Sapporo Medical University, Sapporo, Japan. Electronic address: horio@sapmed.ac.jp.
Yoshiyuki
Y
Horio
D000818:Animals; D002465:Cell Movement; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D008545:Melanoma / Q000378:metabolism*; D008546:Melanoma, Experimental / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis; D009536:Niacinamide / Q000737:chemistry; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D011554:Pseudopodia / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D056564:Sirtuin 1 / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism*
D010982:Platelet-Derived Growth Factor; D034741:RNA, Small Interfering; D009536:Niacinamide; C470545:Sirt1 protein, mouse; D056564:Sirtuin 1