Effects of 5-ALA mediated photodynamic therapy in oral cancer stem cells

Differences in the response of normal oral mucosa, oral leukoplakia, oral squamous cell carcinoma-derived mesenchymal stem cells, and epithelial cells to photodynamic therapy

OBJECTIVE

The objective of this study is to investigate the variances in transcriptome gene expression of normal oral mucosa-derived mesenchymal stem cell (OM-MSC), oral leukoplakia-derived MSC (OLK-MSC) and oral squamous cell carcinoma-derived MSC(OSCC-MSC). as Additionally, the study aims to compare the in vitro proliferation, migration, invasion ability, and response to photodynamic therapy (PDT) of these three MSC, HOK, DOK, leuk1, and Cal27 cell lines.

METHODS

HOK, DOK, leuk1, Cal27 cells were cultured in vitro. 3 MSC cells were obtained from OM, OLK, OSCC tissue (n = 3) and identified through flow cytometry. They were also cultured in vitro for osteogenic and lipogenic-induced differentiation. Based on the Illumina HiSeq high-throughput sequencing platform, OM-MSC, OLK-MSC, OSCC-MSC (n = 3) were subjected to transcriptome sequencing, functional annotation, and enrichment analysis of differentially expressed genes and related genes. CCK8 assay, wound healing assay, and transwell assay were performed to compare the proliferation, migration, and invasion of the seven types of cells. The 7 cells were incubated with 0, 0.125 mM, 0.25 mM, 0.5 mM, 1 mM, and 2 mM of the photosensitizer (5-aminolevulinic acid, 5-ALA) in vitro. Subsequently, they were irradiated with a 150 mM, 635 nm laser for 1 min, and the cell activity was detected using the CCK8 assay after 24 h. The mitochondrial changes in the 7 cells before and after the treatment of PDT were detected using the JC-10 probe, and the changes in ATP content were measured before and after the PDT treatment.

RESULTS

OM-MSC, OLK-MSC, and OSCC-MSC expressed positive MSC surface markers. After osteogenic and lipogenic-induced differentiation culture, stained calcium nodules and lipid droplets were visible, meeting the identification criteria of MSC. Pathway enrichment analysis revealed that the differentially expressed genes (DEGs) of OSCC-MSC compared to OLK-MSC were primarily associated with the PI3K-Akt signaling pathway and tumor-related pathways. OSCC-MSC exhibited stronger migratory and invasive abilities compared to Cal27. The IC50 values required for OM, OLK, and OSCC-derived MSC were lower than those required for epithelial cells treated with PDT, which were 1.396 mM, 0.9063 mM, and 2.924 mM, respectively. Cell membrane and mitochondrial disruption were observed in seven types of cells after 24 h of PDT treatment. However, HOK, DOK, leuk1, and Cal27 cells had an ATP content increased.

CONCLUSIONS

OLK, OSCC epithelial cells require higher concentrations of 5-ALA for PDT treatment than MSC of the same tissue origin. The concentration of 5-ALA required increases with increasing cell malignancy. Differences in the response of epithelial cells and MSC to PDT treatment may have varying impacts on OLK recurrence and malignancy.

Assays on 3D tumor spheroids for exploring the light dosimetry of photodynamic effects under different gaseous conditions

The multifaceted nature of photodynamic therapy (PDT) requires a throughout evaluation of a multitude of parameters when devising preclinical protocols. In this study, we constructed MCF-7 human breast tumor spheroid assays to infer PDT irradiation doses at four gradient levels for violet light at 408 nm and red light at 625 nm under normal and hypoxic oxygen conditions. The compacted three-dimensional (3D) tumor models conferred PDT resistance as compared to monolayer cultures due to heterogenous distribution of photosensitizers along with the presence of internal hypoxic region. Cell viability results indicated that the violet light was more efficient to kill cells in the spheroids under normal oxygen conditions, while cells exposed to the hypoxic microenvironment exhibited minimal PDT-induced death. The combination of 3D tumor spheroid assays and the multiparametric screening platform presented a solid framework for assessing PDT efficacy across a wide range of different physiological conditions and therapeutic regimes.

In vitro modeling of recurrent Dermatofibrosarcoma Protuberans: Assessment of 5-aminolevulinic acid photodynamic therapy efficacy

BACKGROUND

Dermatofibrosarcoma Protuberans (DFSP) is a rare, low-grade malignant tumor of the dermis with a high recurrence rate post-surgery. Current treatments, including surgery, radiotherapy, and targeted therapy, have limitations. Photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) is a promising non-invasive approach, but its efficacy in DFSP treatment remains underexplored.

METHODS

This study aimed to evaluate the anti-tumor efficacy of 5-ALA PDT using an in vitro model derived from a recurrent DFSP patient. The cells were treated with varying concentrations of 5-ALA and exposed to red light, followed by assessments of cell viability, proliferation, apoptosis, migration, invasion, angiogenesis, and expression of DFSP-related genes and proteins.

RESULTS

5-ALA PDT significantly reduced DFSP cell viability in a dose-dependent manner and induced apoptosis. It also effectively inhibited cell proliferation, migration, and invasion, as well as suppressed angiogenic activity in conditioned media. Furthermore, 5-ALA PDT downregulated the expression of COL1A1 and PDGFRB, key genes in DFSP pathogenesis.

CONCLUSIONS

The findings provide the first evidence of 5-ALA PDT's in vitro anti-tumor efficacy against DFSP, suggesting its potential as a novel therapeutic approach for DFSP. Further studies are warranted to explore the clinical utility of 5-ALA PDT in preventing DFSP recurrence.

Photodynamic Therapy for Eye, Ear, Laryngeal Area, and Nasal and Oral Cavity Diseases: A Review

Photodynamic therapy (PDT) has emerged as a promising modality for the treatment of various diseases. This non-invasive approach utilizes photosensitizing agents and light to selectively target and destroy abnormal cells, providing a valuable alternative to traditional treatments. Research studies have explored the application of PDT in different areas of the head. Research is focusing on a growing number of new developments and treatments for cancer. One of these methods is PDT. Photodynamic therapy is now a revolutionary, progressive method of cancer therapy. A very important feature of PDT is that cells cannot become immune to singlet oxygen. With this therapy, patients can avoid lengthy and costly surgeries. PDT therapy is referred to as a safe and highly selective therapy. These studies collectively highlight the potential of PDT as a valuable therapeutic option in treating the head area. As research in this field progresses, PDT may become increasingly integrated into the clinical management of these conditions, offering a balance between effectiveness and minimal invasiveness.

Fractionated Photofrin-Mediated Photodynamic Therapy Significantly Improves Long-Term Survival

This study investigates the effect of fractionated (two-part) PDT on the long-term local control rate (LCR) using the concentration of reactive oxygen species ([ROS]rx) as a dosimetry quantity. Groups with different fractionation schemes are examined, including a 2 h interval between light delivery sessions to cumulative fluences of 135, 180, and 225 J/cm2. While the total treatment time remains constant within each group, the division of treatment time between the first and second fractionations are explored to assess the impact on long-term survival at 90 days. In all preclinical studies, Photofrin is intravenously administered to mice at a concentration of 5 mg/kg, with an incubation period between 18 and 24 h before the first light delivery session. Fluence rate is fixed at 75 mW/cm2. Treatment ensues via a collimated laser beam, 1 cm in diameter, emitting light at 630 nm. Dosimetric quantities are assessed for all groups along with long-term (90 days) treatment outcomes. This study demonstrated a significant improvement in long-term survival after fractionated treatment schemes compared to single-fraction treatment, with the optimal 90-day survival increasing to 63%, 86%, and 100% vs. 20%, 25%, and 50%, respectively, for the three cumulative fluences. The threshold [ROS]rx for the optimal scheme of fractionated Photofrin-mediated PDT, set at 0.78 mM, is significantly lower than that for the single-fraction PDT, at 1.08 mM.

Photodynamic therapy in cancer stem cells - state of the art

Despite significant efforts to control cancer progression and to improve oncology treatment outcomes, recurrence and tumor resistance are frequently observed in cancer patients. These problems are partly related to the presence of cancer stem cells (CSCs). Photodynamic therapy (PDT) has been developed as a therapeutic approach for solid tumors; however, it remains unclear how this therapy can affect CSCs. In this review, we focus on the effects of PDT on CSCs and the possible changes in the CSC population after PDT exposure. Tumor response to PDT varies according to the photosensitizer and light parameters employed, but most studies have reported the successful elimination of CSCs after PDT. However, some studies have reported that CSCs were more resistant to PDT than non-CSCs due to the increased efflux of photosensitizer molecules and the action of autophagy. Additionally, using different PDT approaches to target the CSCs resulted in increased sensitivity, reduction of sphere formation, invasiveness, stem cell phenotype, and improved response to chemotherapy. Lastly, although mainly limited to in vitro studies, PDT, combined with targeted therapies and/or chemotherapy, could successfully target CSCs in different solid tumors and promote the reduction of stemness, suggesting a promising therapeutic approach requiring evaluation in robust pre-clinical studies.

Red Light and 5% Aminolaevulinic Acid (5%) Inhibit Proliferation and Migration of Dysplastic Oral Keratinocytes via ROS Production: An In Vitro Study

Undiagnosed and untreated oral precancerous lesions often progress into malignancies. Photodynamic therapy (PDT) might be a minimally invasive alternative to conventional treatments. 5-aminolevulinic acid (5-ALA) is one of the most commonly used photosensitizers in PDT, and it is effective on many cancer types. However, its hydrophilic characteristic limits cell membrane crossing. In the present study, the effect of a newly formulated gel containing 5% 5-ALA in combination with red light (ALAD-PDT) on a premalignant oral mucosa cell line was investigated. The dysplastic oral keratinocyte (DOK) cells were incubated with ALAD at different concentrations (0.1, 0.5, 1, and 2 mM) at two different times, 45 min or 4 h, and then irradiated for 7 min with a 630 nm LED (25 J/cm2). MTT assay, flow cytometry, wound healing assay, and quantitative PCR (qPCR) were performed. ALAD-PDT exerted inhibitory effects on the proliferation and migration of DOK cells by inducing ROS and necrosis. mRNA analysis showed modulation of apoptosis-related genes' expression (TP53, Bcl-2, survivin, caspase-3, and caspase-9). Furthermore, there was no difference between the shorter and longer incubation times. In conclusion, the inhibitory effect of the ALAD-PDT protocol observed in this study suggests that ALAD-PDT could be a promising novel treatment for oral precancerous lesions.

Insight on nano drug delivery systems with targeted therapy in treatment of oral cancer

Oral cancer is a type of cancer that develops in the mouth and is one of the deadliest malignancies in the world. Currently surgical, radiation therapy, and chemotherapy are most common treatments. Better treatment and early detection strategies are required. Chemotherapeutic drugs fail frequently due to toxicity and poor tumor targeting. There are high chances of failure of chemotherapeutic drugs due to toxicity. Active, passive, and immunity-targeting techniques are devised for tumor-specific activity. Nanotechnology-based drug delivery systems are the best available solution and important for precise targeting. Nanoparticles, liposomes, exosomes, and cyclodextrins are nano-based carriers for drug delivery. Nanotechnology is being used to develop new techniques such as intratumoral injections, microbubble mediated ultrasonic therapy, phototherapies, and site-specific delivery. This systematic review delves into the details of such targeted and nano-based drug delivery systems in order to improve patient health and survival rates in oral cancer.

Significance of Singlet Oxygen Molecule in Pathologies

Reactive oxygen species, including singlet oxygen, play an important role in the onset and progression of disease, as well as in aging. Singlet oxygen can be formed non-enzymatically by chemical, photochemical, and electron transfer reactions, or as a byproduct of endogenous enzymatic reactions in phagocytosis during inflammation. The imbalance of antioxidant enzymes and antioxidant networks with the generation of singlet oxygen increases oxidative stress, resulting in the undesirable oxidation and modification of biomolecules, such as proteins, DNA, and lipids. This review describes the molecular mechanisms of singlet oxygen production in vivo and methods for the evaluation of damage induced by singlet oxygen. The involvement of singlet oxygen in the pathogenesis of skin and eye diseases is also discussed from the biomolecular perspective. We also present our findings on lipid oxidation products derived from singlet oxygen-mediated oxidation in glaucoma, early diabetes patients, and a mouse model of bronchial asthma. Even in these diseases, oxidation products due to singlet oxygen have not been measured clinically. This review discusses their potential as biomarkers for diagnosis. Recent developments in singlet oxygen scavengers such as carotenoids, which can be utilized to prevent the onset and progression of disease, are also described.