High doses of laser phototherapy can increase proliferation in melanoma stromal connective tissue

Autor(es)

Frigo, Lucio ^[1] ; Cordeiro, Joseli Maria ^[1] ; Favero, Giovani Marino ^[2] ; Maria, Durnavei Augusto ^[3] ; Pinto Leal-Junior, Ernesto Cesar ^[4] ; Joensen, Jon ^[5] ; Bjordal, Jan Magnus ^{[5, 6]} ; Roxo, Denise Carvalho ^[1] ; Marcos, Rodrigo Labat ^{[4, 7]} ; Brandao Lopes-Martins, Rodrigo Alvaro ^[8]

Afiliação do(s) autor(es)

^[1] Univ Cruzeiro Sul, Biol Sci & Hlth Ctr, Ave Dr Ussiel Cirilo, 225 Sao Miguel Paulista, BR-08060070 Sao Paulo, SP - Brazil

^[2] Univ Estadual Ponta Grossa, Gen Biol Dept, Ave Gal Carlos Cavalcanti 4748, BR-84030900 Ponta Grossa, PR - Brazil

^[3] Butantan Inst, Lab Biochem & Biophys, Ave Dr Vital Brasil 1500, BR-05599000 Sao Paulo, SP - Brazil

^[4] Nove Julho Univ UNINOVE, Rua Vergueiro 235, BR-01504001 Sao Paulo, SP - Brazil

^[5] Bergen Univ Coll, Inst Physiotherapy, Moellendalsvn 6, N-5009 Bergen - Norway

^[6] Univ Bergen, Dept Global & Publ Hlth, Physiotherapy Res Grp, Kalfarveien 31, N-5018 Bergen - Norway

^[7] Univ Nove Julho, Biophoton Appl Hlth Sci, Rua Vergueiro 235, BR-01504001 Sao Paulo, SP - Brazil

^[8] Univ Vale Paraiba, Ave Shishima Hifumi 2911, BR-12244000 Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Lasers in Medical Science; v. 33, n. 6, p. 1215-1223, AUG 2018.
• Citações Web of Science: 0

Resumo

It is well established that laser phototherapy (LP) is contraindicated directly over cancer cells, due to its bio modulatory effects in cell and blood vessel proliferation. The aim of the present study was to analyze the influence of typical low-level laser therapy (LLLT) and high intensity laser therapy (HILT) and an in-between dose of 9 J on collagen fibers and blood vessels content in melanoma tumors (B16F10) implanted in mice. Melanoma tumor cells were injected in male Balb C mice which were distributed in four groups: control (no irradiated) or irradiated by 3, 9, or 21 J (150; 450, or 1050 J/cm(2)). LP was performed in daily sessions for 3 days with a InGaAlP-660 nm (mean output: 50 mW, spot size: 2 mm(2)). Tumor volume was analyzed using (1) picrosirius staining to quantify collagen fibers content and (2) Verhoeff's method to quantify blood vessels content. Tumor growth outcome measured in the 3-J group was not significantly different from controls. Nine and 21-J groups, presented significant and dose-dependent increases in tumor volume. Quantitative analysis of the intensity of collagen fibers and their organization in stroma and peri-tumoral microenvironment showed significant differences between irradiated and control group. Blood vessels count of 21-J group outnumbered the other groups. High doses (>= 9 J) of LP showed a dose-dependent tumor growth, different collagen fibers characteristics, and eventually blood vessel growth, while a typical LLLT dose (3 J) appeared harmless on melanoma cell activity. (AU)

• Processo FAPESP: 07/59124-0 - Avaliação dos efeitos da terapia fotodinâmica com azul de metileno no modelo experimental de ratos com tumor de Walker 256
• Beneficiário: Lúcio Frigo
• Modalidade de apoio: Auxílio à Pesquisa - Regular