In Vitro Anti-tumor Effects of Photodynamic Therapy on Oral Squamous Cell Carcinoma: A Review

Abstract

Introduction: Due to the increasing prevalence and high mortality rate of oral squamous cell carcinoma (OSCC) and problems with its routine treatments, more recent modalities like photodynamic therapy (PDT) have been developed. PDT effectively destroys tumor cells with minimum side effects. Research on in vitro effects of PDT may be helpful in determining the molecular mechanisms responsible for its effectiveness and can lead to the development of more efficient techniques. The aim of this study was to review the use of PDT in OSCC among in vitro studies. Methods: A literature search for English articles on PDT in OSCC was performed in PubMed, Scopus, Google Scholar, and Web of Science. Data were extracted based on the inclusion/exclusion criteria, which were detailed using the PICO framework: all eligible in vitro studies evaluating the effects of PDT on the viability of OSCC compared to controls without PDT were included. Results: Forty-one out of 567 studies were selected. The tongue was the most common OSCC site, 5-aminolevulinic acid was the most used photosensitizer (PS), cell viability/toxicity and apoptosis were the most evaluated outcomes, and lasers with wavelengths of 600-700 nm were the most common light sources and wavelengths respectively. Conclusion: PDT showed promising effects on reducing the viability of OSCC cells. Cell lines from various sources or even those originating from the same location sometimes responded differently to the same protocol. Considering the favorable results obtained from natural PSs and regarding their additional health-promoting properties, their use in future investigations with different cell lines and light specifications is recommended.

Photodynamic therapy induced cell cycle arrest and cancer cell synchronization: review

“…They confirmed that PaH-PDT increases the percentage of cells in the G0/G1 phase and decreases the CDK2 and cyclin E1 protein levels ( 135 ). However, it is shown that 5-aminolaevulinic acid (5-ALA) as a second generation of protoporphyrin IX PSs in PDT has no effect on CC but, as radiosensitizer (for gamma radiation), can stop oral squamous cell carcinoma at G2/M stage ( 136 , 137 ). Furthermore, it is reported by Sengupta and collogues that Fe 3 O 4 nanoparticles (NPs) on porphyrins has immune-protective effects and capable apoptosis via upregulations of p21 kinase by CCA at the G0/G1 stage in AGS and RAW cell lines ( 140 , 142 ).…”

Indocyanine-Green-Loaded Liposomes for Photodynamic and Photothermal Therapies: Inducing Apoptosis and Ferroptosis in Cancer Cells with Implications beyond Oral Cancer

“…Compared with the predominantly utilized photosensitizer, 5-aminolevulinic acid (5-ALA), which exhibits excitation and emission within the visible light spectrum, ICG demonstrates excitation and emission within the near-infrared wavelength range [ 6 ]. This characteristic facilitates a significantly enhanced penetration depth in human tissues, consequently potentially leading to a more profound tumor eradication capacity [ 7 , 8 ]. Previous research conducted in our laboratory has revealed that ICG can induce ferroptosis in cancer cells when exposed to infrared light, and its photothermal effect after NIR irradiation has also been reported [ 9 ].…”

PDT-Induced Activation Enhanced by Hormone Response to Treatment

“…Despite its low popularity, this is a well-tested, clinically approved, and effective method of cancer treatment [ 4 , 5 , 6 ]. Accurate knowledge of PDT mechanisms gives a chance for better understanding of this treatment [ 7 ]. Additionally, PDT causes cellular acting, including an impact on the endocrine and immunological pathways.…”