title: Low-level laser therapy promotes proliferation and invasion of oral squamous cell carcinoma cells.
abstract: Low-level laser therapy (LLLT) has been shown to be effective in promoting cell proliferation. There is speculation that the biostimulatory effect of LLLT causes undesirable enhancement of tumor growth in neoplastic diseases since malignant cells are more susceptible to proliferative stimuli. This study evaluated the effects of LLLT on proliferation, invasion, and expression of cyclin D1, E-cadherin, β-catenin, and MMP-9 in a tongue squamous carcinoma cell line (SCC25). Cells were irradiated with a diode laser (660 nm) using two energy densities (0.5 and 1.0 J/cm(2)). The proliferative potential was assessed by cell growth curves and cell cycle analysis, whereas the invasion of cells was evaluated using a Matrigel cell invasion assay. Expression of cyclin D1, E-cadherin, β-catenin, and MMP-9 was analyzed by immunofluorescence and flow cytometry and associated with the biological activities studied. LLLT induced significantly the proliferation of SCC25 cells at 1.0 J/cm(2), which was accomplished by an increase in the expression of cyclin D1 and nuclear β-catenin. At 1.0 J/cm(2), LLLT significantly reduced E-cadherin and induced MMP-9 expression, promoting SCC25 invasion. The results of this study demonstrated that LLLT exerts a stimulatory effect on proliferation and invasion of SCC25 cells, which was associated with alterations on expression of proteins studied.
authors: Department of Dentistry, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors: Águida Cristina
authors: ÁC
authors: Gomes Henriques
authors: Fernanda
authors: F
authors: Ginani
authors: Ruth Medeiros
authors: RM
authors: Oliveira
authors: Tatjana Souza Lima
authors: TS
authors: Keesen
authors: Carlos Augusto
authors: CA
authors: Galvão Barboza
authors: Hugo Alexandre
authors: HA
authors: Oliveira Rocha
authors: Jurema Freire Lisboa
authors: JF
authors: de Castro
authors: Ricardo
authors: R
authors: Della Coletta
authors: Roseana
authors: R
authors: de Almeida Freitas
mesh_terms: D015820:Cadherins / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology* / Q000532:radiotherapy*; D002453:Cell Cycle / Q000528:radiation effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000528:radiation effects; D019938:Cyclin D1 / Q000378:metabolism; D006801:Humans; D028022:Low-Level Light Therapy; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D009062:Mouth Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000532:radiotherapy*; D009361:Neoplasm Invasiveness; D051176:beta Catenin / Q000378:metabolism
chemical_list: C530104:CCND1 protein, human; D015820:Cadherins; D051176:beta Catenin; D019938:Cyclin D1; D020780:Matrix Metalloproteinase 9