Secondary reactive oxygen species production after PDT during pulmonary tumor growth in sera of nude mice

Photocaged DNA-Binding Photosensitizer Enables Photocontrol of Nuclear Entry for Dual-Targeted Photodynamic Therapy

Photodynamic therapy (PDT) is a clinically approved cancer treatment that requires a photosensitizer (PS), light, and molecular oxygen─a combination which produces reactive oxygen species (ROS) that can induce cancer cell death. To enhance the efficacy of PDT, dual-targeted strategies have been explored where two photosensitizers are administered and localize to different subcellular organelles. To date, a single small-molecule conjugate for dual-targeted PDT with light-controlled nuclear localization has not been achieved. We designed a probe composed of a DNA-binding PS (Br-DAPI) and a photosensitizing photocage (WinterGreen). Illumination with 480 nm light removes WinterGreen from the conjugate and produces singlet oxygen mainly in the cytosol, while Br-DAPI localizes to nuclei, binds DNA, and produces ROS using one- or two-photon illumination. We observe synergistic photocytotoxicity in MCF7 breast cancer cells, and a reduction in size of three-dimensional (3D) tumor spheroids, demonstrating that nuclear/cytosolic photosensitization using a single agent can enhance PDT efficacy.

The localization of the photosensitizer determines the dynamics of the secondary production of hydrogen peroxide in cell cytoplasm and mitochondria

Photodynamic therapy (PDT) is based on the production of the cytotoxic reactive oxygen species (ROS) by light irradiation of a photosensitizer dye in the presence of molecular oxygen. Along with photochemical ROS production, it becomes evident that PDT induces massive secondary production of ROS which is registered long after the irradiation is completed. We created cell lines of human epidermoid carcinoma with the cytoplasmic and mitochondrial localization of protein sensor HyPer sensitive to hydrogen peroxide to compare its concentration in two cellular compartments. The lag-period between irradiation and accumulation of hydrogen peroxide in cells was registered; its duration was dose-dependent and increased up to 80 min when lowering the exposition dose from 50 to 15 J/cm². We have shown that localization of the photosensitizer determines the spatiotemporal pattern of the cell response to PDT: secondary hydrogen peroxide accumulation in cell cytoplasm induced by photodynamic treatment with lysosome-localized phtalocyianine Photosens occurs several minutes prior to that in mitochondria; on the contrary, membranotropic arylcyanoporphyrazine dye leads to massive mitochondrial hydrogen peroxide production followed by its cytoplasmic accumulation. We hypothesize that photosensitizers with various physicochemical properties and intracellular localization can trigger different patterns not only of primary but also secondary ROS production leading to different cell fate outcomes.

Therapeutic evaluation of 5-aminolevulinic acid-mediated photodynamic therapy in Bowenoid papulosis

BACKGROUND

Bowenoid papulosis is a polymorphic papular disease that occurs on the external genital area. We investigated the efficacy of 5-aminolevulinic acid-mediated photodynamic therapyin the treatment of Bowenoid papulosis.

METHODS

We investigated 200 Bowenoid papulosis cases from the Department of Dermatology and Venereology of Nanfang Hospital in 2016-2018. Biopsies were performed from Bowenoid papulosis lesions before treatment. The patients were divided into two groups: 100 patients each in the 5-aminolevulinic acid-mediated photodynamic therapy and control groups(radiofrequency cauterisation, microwave ablation, and surgical resection groups). Differences in lesion clearance, recurrence rate, and patient satisfaction after treatment were evaluated.

RESULTS

Photodynamic therapy sessions for multifocal Bowenoid papulosis were more frequent than those for monofocal lesions. All lesions in the 5-aminolevulinic acid-mediated photodynamic therapy group were cleared after photodynamic therapy, with no recurrence at the 1-year follow-up; however, 20 (20.0 %) patients in the control showed recurrence after 1 year. Only 5patients in the photodynamic group were unsatisfied with the treatment cost and 34 patients in the control group experienced short-term pain and scarring. The recurrence rate was significantly lower (P < 0.05) and patient satisfaction was higher (P < 0.05) in the 5-aminolevulinic acid-mediated photodynamic therapy group than those in the control. The recurrence rate was significantly lower (P < 0.05) and patient satisfaction was higher (P < 0.05) in the 5-aminolevulinic acid-mediated photodynamic therapy group than those in the surgical resection group. The recurrence rate of lesions was significantly lower in the surgical resection group than that in the rest of the control group (P < 0.05). There was no difference in recurrence rate and patient satisfaction between the radiofrequency cauterisation and microwave ablation groups.

CONCLUSIONS

5-aminolevulinic acid-mediated photodynamic therapy for Bowenoid papulosis results in a low recurrence rate and high satisfaction.

Involvement of retinoblastoma-associated protein 48 during photodynamic therapy of cervical cancer cells

5-Aminolevulinic acid-mediated photodynamic therapy (ALA‑PDT) is an effective treatment option for cervical intraepithelial neoplasia, the precancerous lesion of cervical cancer, and early cervical cancer, particularly for young or nulliparous women who want to remain fertile. A previous report described the involvement of histone deacetylases (HDAC) during ALA‑PDT mediated apoptosis in the cerebral cortex of a mouse model. Retinoblastoma‑associated protein 48 (RbAp48), a highly abundant component of HDACs, is a critical mediator that controls the transforming activity of human papillomavirus 16 in cervical cancer cells. The aim of the present study was to investigate the involvement of RbAp48 in ALA‑PDT‑induced cell death in cervical cancer cells. RbAp48 was significantly upregulated in cervical cancer cell lines treated with ALA‑PDT, including SiHa and HeLa cells. To establish the relevance of RbAp48 and the efficacy of ALA‑PDT in cervical cancer cells, the effect of ALA‑PDT was investigated in SiHa or HeLa cells following the depletion of RbAp48 by small interfering RNA (siRNA). Reduction of RbAp48 led to the reduced suppression of proliferation and apoptosis induced by ALA‑PDT in cervical cancer cells, which was associated with a reduction in tumor suppressor protein 53 (p53), retinoblastoma (Rb), apoptosis‑related enzyme caspase‑3, and increased levels of the oncogenic genes, human papillomavirus E6 and E7. These results provide evidence that RbAp48 is an important contributor to the efficacy of ALA‑PDT in cervical cancer cells. RbAp48 may be a therapeutic target that may help to improve the treatment of cervical cancer.

Influence of Vitamins on Secondary Reactive Oxygen Species Production in Sera of Patients with Resectable NSCLC

BACKGROUND

Singlet oxygen (¹O₂) oxidizes targets through the production of secondary reactive oxygen species (SOS). Cancers induce oxidative stress changing with progression, the resulting antioxidant status differing from one patient to the other. The aim of this study was to determine the oxidative status of patients with resectable Non-Small cell lung cancers (NSCLC) and the potential influence of antioxidants, compared to sera from healthy donors.

MATERIALS AND METHODS

Serum samples from 10 women and 28 men, 19 adenocarcinomas (ADK), 15 patients N1 or M1 were submitted to a photoreaction producing ¹O₂. Then, samples were supplemented with vitamins (Vit C, Vit E), or glutathione (GSH).

RESULTS

Squamous cell carcinomas (SCC) and metastatic SCCs induced a lower SOS rate. While Vit C increased SOS in controls as in patients with metastases, Vit E or the combination of Vit E and C strongly reduced SOS. GSH alone lightly decreased SOS in controls but had no effect in patients either alone or combined with Vit C.

CONCLUSION

In "early" lung cancers, SOS are comparable or lower than for healthy persons. The role of Vitamins varies with gender, cancer type, and metastases. This suggests that an eventual supplementation should be performed on a per-patient basis to evidence any effect.

Treatment of near-infrared photodynamic therapy using a liposomally formulated indocyanine green derivative for squamous cell carcinoma

INTRODUCTION

Photodynamic therapy (PDT) is a less invasive option for cancer treatment that has evolved through recent developments in nanotechnology. We have designed and synthesized a novel liposome system that includes an indocyanine green (ICG) derivative, ICG-C18, in its bilayer. In addition to its use as an optical imager to visualize blood, lymphatic, and bile flow, ICG has also been used as an optical sensitizer. In the present report, we evaluate the use of our novel liposome system, LP-ICG-C18, in PDT for squamous cell carcinoma in an autologous murine model.

MATERIALS AND METHODS

An excitation pulse beam (300 μJ/pulse) of a single band (800 nm) was used for sensitization. The cytotoxicity of the photodynamic therapy was evaluated in terms of cellular morphology changes, methyl thiazolyl tetrazolium (MTT) assay results, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining. We tested the enhanced permeability and retention effect of LP-ICG-C18 in tumor-bearing C3H/He mice using a near-infrared fluorescence imaging system and fluorescence microscopy. We also examined the antitumor effect of PDT by measuring tumor volume in tumor-bearing mice.

RESULTS

Cell death and apoptosis were only observed in the PDT group receiving LP-ICG-C18. LP-ICG-C18 itself had no cytotoxic activity and showed good biocompatibility. LP-ICG-C18 accumulated on the tumor 24 hours after injection and was retained for approximately 3 weeks. Tumor cell apoptosis following PDT with LP-ICG-C18 was also observed under optical microscopy, MTT assay, and TUNEL staining.

CONCLUSION

These findings suggest that LP-ICG-C18 may be an effective intervening material in PDT for malignant disease.