Korean J Phys Anthropol.  2011 Dec;24(4):203-216.

Mechanism Underlying NaF-induced Apoptosis and Cell Cycle Arrest on G361 Human Melanoma Cell Line

• Kim DK
• Sohn HJ
• Kim IR
• Kim GC
• Park BS
• Kwak HH

Abstract

Fluoride is widely used in dentistry to prevent dental caries, even though the safety of fluoride is a controversial issue. There are no known adverse effects of long-term fluoride ingestion for caries prevention, but an overdose can cause serious acute toxicity. Nevertheless it is accepted that fluoride is an important material for oral health. This study was undertaken to investigate the modulation of cell cycle-related proteins and apoptosis induction underlying mechanism by NaF treatment on G361 human melanoma cell line. The viability of G361 cells and the growth inhibition of G361 cells were assessed by MTT assay and clonogenic assay respectively. Hoechst staining, DNA electrophoresis and TUNEL staining were conducted to observe G361 cells undergoing apoptosis. G361 cells were treated with NaF, and Western blotting, immunocytochemistry, confocal microscopy, FACScan flow cytometry, MMP activity and proteasome activity were performed. NaF treatment in G361 cells resulted in a time- and does-dependent decrease of cell viability and a does-dependent inhibition of cell growth, and induced apoptotic cell death. And tested G361 cells showed several lines of apoptotic manifestation such as nuclear condensation, DNA fragmentation, the reduction of MMP and proteasome activity, the decrease of DNA contents, the release of cytochrome c into cytosol, the translocation of AIF and DFF40 (CAD) onto nuclei, a significant shift of Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-7, caspase-6, caspase-3, PARP, Lamin A/C and DFF45 (ICAD). Furthermore, NaF resulted in down-regulation of the G1 cell cycle-related proteins, and up-regulation of p53. Taken collectively, our present findings demonstrate that NaF strongly inhibits cell proliferation by modulating the expression of the G1 cell cycle-related proteins and induces apoptosis via proteasome, mitochondria and caspase cascades in G361 cells.

Keyword

NaF; Apoptosis; Cell cycle arrest; Human melanoma cells

MeSH Terms

Apoptosis
Blotting, Western
Caspase 3
Caspase 6
Caspase 7
Caspase 9
Cell Cycle
Cell Cycle Checkpoints
Cell Death
Cell Line
Cell Proliferation
Cell Survival
Cytochromes c
Cytosol
Dental Caries
Dentistry
DNA
DNA Fragmentation
Down-Regulation
Eating
Electrophoresis
Flow Cytometry
Fluorides
Humans
Immunohistochemistry
In Situ Nick-End Labeling
Melanoma
Microscopy, Confocal
Mitochondria
Oral Health
Proteasome Endopeptidase Complex
Proteins
Up-Regulation
Caspase 3
Caspase 6
Caspase 7
Caspase 9
Cytochromes c
DNA
Fluorides
Proteasome Endopeptidase Complex
Proteins