Effect of low-level light therapy before radiotherapy in oral squamous cell carcinoma: An in vitro study

• Published in: Lasers in medical science 2022-12, Vol.37 (9), p.3527-3536
• Main Authors: Tabosa, Angeliny Tamiarana Lima, Souza, Marcela Gonçalves, de Jesus, Sabrina Ferreira, Rocha, Danielle Ferreira, Queiroz, Lorena dos Reis Pereira, Santos, Eloá Mangabeira, Guimarães, Victor Hugo Dantas, Andrade, Luciano Alves de Araújo, Santos, Sérgio Henrique, de Paula, Alfredo Maurício Batista, de Souza, Paulo Eduardo Narcizo, Farias, Lucyana Conceição, Guimarães, André Luiz Sena
• Format: Article
• Language: English
• Subjects: Apoptosis; Cancer; Cell death; Cell migration; Cell proliferation; Cell survival; Complications; Dentistry; Head & neck cancer; Head and neck carcinoma; Intracellular levels; Ionizing radiation; Lasers; Light emitting diodes; Light therapy; Medicine; Medicine & Public Health; Mortality; Optical Devices; Optics; Oral cancer; Oral carcinoma; Oral squamous cell carcinoma; Original Article; Photonics; Phototherapy; Quantum Optics; Radiation dosage; Radiation therapy; Reactive oxygen species; Side effects; Squamous cell carcinoma; Survival
• ISSN: 1435-604X; 0268-8921; 1435-604X
• DOI: 10.1007/s10103-022-03632-x

Radiation therapy for head and neck squamous cell carcinoma (HNSCC) is associated with several complications. Although photobiomodulation (PBM) has radioprotective effects in normal tissue, it could also enhance the growth of neoplastic cells. Thus, the present study aimed to investigate the cellular response of oral squamous cell carcinoma with pre-exposure to low-level phototherapy before radiotherapy. SCC9, Cal-27, A431, and HaCaT cell lines were subjected to low-level light therapy and radiotherapy. The cells were treated with a single energy density (300 J/cm 2 ) of a light-emitting diode (660 nm) prior to ionizing radiation at different doses (0, 2, 4, and 6 Gy). After 24 h, wound scratch, proliferation, clonogenic cell survival, cell death, and reactive oxygen species (ROS) analyses were performed to evaluate cell response. The cell lines pre-exposed to PBM at the analyzed dosage were radiosensitive. The treatment significantly reduced cell proliferation and clonogenic cell survival. Migration and cell death assays also revealed positive results, with the treatment group showing lower rate of migration and higher cell death than did the control group. Moreover, PBM effectively increased the intracellular levels of ROS. PBM at 300 J/cm 2 is a promising radiosensitizing modality to reduce the radiation dose and avoid the intolerable side effects of radiotherapy for HNSCC, thus increasing the probability of successful treatment. However, further studies are needed to support and confirm the results.