Differences in sensitivity to HMME-mediated photodynamic therapy between EBV+ C666-1 and EBV− CNE2 cells

Clinical efficacy and safety of two different hematoporphyrin monomethyl ether-mediated photodynamic therapy regimen in Chinese children with port-wine stain

Hematoporphyrin monomethyl ether-photodynamic therapy (HMME-PDT) has achieved encouraging clinical outcomes in adult port-wine stain (PWS). Optimal treatment option for children with PWS was minimal. To compare whether the clinical effectiveness of HMME-PDT with the 5-min (fast) administration treatment regimen (FATR) was better than the 20-min (slow) administration treatment regimen (SATR) for PWS of children in vivo and in vitro. Thirty-four children with PWS were divided into two groups including FATR and SATR. The two groups received three times HMME-PDT, respectively. Treatment efficacy and safety were evaluated in vivo and in vitro. Erythema index (EI) was used to evaluate the clinical outcomes. Both FATR and SATR were effective and safe in children with PWS after HMME-PDT. There were significance differences between the two groups in reductions of EI after the second treatment (p < 0.001) and the third treatment (p < 0.001) with HMME-PDT. The serum HMME concentration reach the peak level at short time compare with SATR group. A significance increased superoxide levels were observed in FATR group compare to SATR groups in vitro (p < 0.05). Our study suggested that HMME-PDT was effective and safe for children with PWS, the therapy regimen with FATR was better in clinical efficacy than that of the SATR.

Photodynamic Therapy Can Modulate the Nasopharyngeal Carcinoma Microenvironment Infected with the Epstein-Barr Virus: A Systematic Review and Meta-Analysis

Nasopharyngeal carcinoma is a malignancy from epithelial cells predominantly associated with the Epstein-Barr virus (EBV) infection, and it is responsible for 140,000 deaths annually. There is a current need to develop new strategies to increase the efficacy of antineoplastic treatment and reduce side effects. Thus, the present study aimed to perform a systematic review and meta-analysis of the ability of photodynamic therapy (PDT) to modulate the tumor microenvironment and PDT efficacy in nasopharyngeal carcinoma treatment. The reviewers conducted all steps in the systematic review. PubMed, Science Direct, Scopus, Scielo, Lilacs, EMBASE, and the Cochrane library databases were searched. The OHAT was used to assess the risk of bias. Meta-analysis was performed with a random-effects model (α = 0.05). Nasopharyngeal carcinoma cells treated with PDT showed that IL-8, IL-1α, IL-1β, LC3BI, LC3BII, MMP2, and MMP9 levels were significantly higher than in groups that did not receive PDT. NF-ĸB, miR BART 1-5p, BART 16, and BART 17-5p levels were significantly lower in the PDT group than in the control group. Apoptosis levels and the viability of nasopharyngeal carcinoma cells (>70%) infected with EBV were effective after PDT. This treatment also increased LMP1 levels (0.28-0.50/p < 0.05) compared to the control group. PDT showed promising results for efficacy in killing nasopharyngeal carcinoma cells infected with EBV and modulating the tumor microenvironment. Further preclinical studies should be performed to validate these results.

Multi-Modal Optical Imaging and Combined Phototherapy of Nasopharyngeal Carcinoma Based on a Nanoplatform

Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck with a high incidence rate worldwide, especially in southern China. Phototheranostics in combination with nanoparticles is an integrated strategy for enabling simultaneous diagnosis, real-time monitoring, and administration of precision therapy for nasopharyngeal carcinoma (NPC). It has shown great potential in the field of cancer diagnosis and treatment owing to its unique noninvasive advantages. Many Chinese and international research teams have applied nano-targeted drugs to optical diagnosis and treatment technology to conduct multimodal imaging and collaborative treatment of NPC, which has become a hot research topic. In this review, we aimed to introduce the recent developments in phototheranostics of NPC based on a nanoplatform. This study aimed to elaborate on the applications of nanoplatform-based optical imaging strategies and treatment modalities, including fluorescence imaging, photoacoustic imaging, Raman spectroscopy imaging, photodynamic therapy, and photothermal therapy. This study is expected to provide a scientific basis for further research and development of NPC diagnosis and treatment.

Evaluation of the photodynamic efficacy and effects of haematoporphyrin monomethyl ether on Trichophyton rubrum microconidia in vitro

BACKGROUND

Current available treatment modes against dermatophytoses are often tedious and sometimes unsatisfactory. As an emerging and promising approach, antimicrobial photodynamic therapy (aPDT) attracts much attention in the treatment of superficial or localised infections.

OBJECTIVES

This work investigated the photodynamic efficacy and effects of haematoporphyrin monomethyl ether (HMME) on microconidia of Trichophyton rubrum in vitro.

METHODS

The photodynamic killing efficacy of HMME on microconidia of two T rubrum strains was assessed by MTT assay. The effects of HMME-mediated aPDT on the growth of T rubrum and cellular structure of microconidia were also investigated. Confocal laser scanning microscopy (CLSM) and flow cytometry were employed to study the intracellular localisation of HMME and generation of reactive oxygen species (ROS).

RESULTS

HMME showed no obvious toxicity in the dark, but after light irradiation it inactivated the T rubrum microconidia in a light energy dose-dependent manner, and inhibited the growth of T rubrum. CLSM demonstrated that HMME initially bound to the cell envelop and entered into the cell after light irradiation. HMME-mediated aPDT also damaged the cell cytoplasm and increased the accumulation of intracellular ROS, resulting in cell death.

CONCLUSIONS

The results suggested that HMME-mediated aPDT had potential to be used in the treatment of superficial infections caused by T rubrum.

Comparative study of FosPeg® photodynamic effect on nasopharyngeal carcinoma cells in 2D and 3D models

Photodynamic Therapy (PDT) offers an alternative option for the treatment of nasopharyngeal carcinoma (NPC). The utilization of 3-dimensional (3D) culture model might provide better understanding of PDT effects on NPC cells. The aim of this in vitro study was to compare PDT effect on NPC cells using 2D and 3D models. Two 3D culture models were established using liquid overlay method with agarose base (MCL) and hanging drop method (MCS). PDT was carried out using the combination of FosPeg® and 652 nm laser in 3D and conventional 2D models. The effects of 3D culture size and morphology on the uptake and distribution of sensitizer and gene expression were examined. Photocytotoxity, mode of cell death, and protein expression were compared for 2D and 3D models. Regular and irregular NPC spheroids were obtained from MCL and MCS methods, respectively. A significantly down-regulation of LMP1 mRNA were observed in MCL spheroid. The sensitizer uptake in 3D spheroids was half of 2D culture. More sensitizers were required to obtain IC₅₀ in 3D spheroids. Apoptosis, necrosis and autophagosomes were detected in PDT treated 2D and 3D cells. Different protein expression patterns were observed in 2D and 3D models. FosPeg® PDT is effective in killing NPC cells. MCL-derived 3D spheroid model is more suitable for the evaluation of PDT killing mechanisms.

Evaluation of the effect of 5-aminolevulinic acid hexyl ester (H-ALA) PDT on EBV LMP1 protein expression in human nasopharyngeal cells

Nasopharyngeal carcinoma (NPC) is of high prevalence in Hong Kong and southern China. The pathogenesis of NPC is closely associated with Epstein-Barr virus (EBV) infection via regulation of viral oncoprotein latent membrane protein 1 (LMP1). The conventional treatment for NPC is chemo-radiotherapy, but the prognosis remains poor for advanced stage, recurrent and metastatic NPC. Photodynamic therapy (PDT) is a therapeutic approach to combat tumors. PDT effectiveness depends on the interaction of photosensitizers, light and molecular oxygen. 5- aminolevulinic acid hexyl derivative (H-ALA) is one of the photosensitizers derived from 5-ALA. H-ALA with improved lipophilic properties by adding a long lipophilic chain (hexyl group) to 5-ALA, resulted in better penetration into cell cytoplasm. In this study, the effect of H-ALA-PDT on NPC cells (EBV positive C666-1 and EBV negative CNE2) was investigated. The H-ALA mediated cellular uptake and cytotoxicity was revealed via flow cytometry analysis and MTT assay respectively. H-ALA PDT mediated protein modulation was analysed by western blot analysis. Our finding reported that the cellular uptake of H-ALA in C666-1 and CNE2 cells was in a time dependent manner. H-ALA PDT was effective to C666-1 and CNE2 cells. EBV LMP1 proteins was expressed in C666-1 cells only and its expression was responsive to H-ALA PDT in a dose dependent manner. This work revealed the potential of H-ALA PDT as a treatment regiment for EBV positive NPC cells. Understanding the mechanism of H-ALA mediated PDT could develop improved strategies for the treatment of NPC.

Hematoporphyrin monomethyl ether-mediated photodynamic therapy inhibits the growth of keloid graft by promoting fibroblast apoptosis and reducing vessel formation

Photodynamic therapy (PDT) has been shown to significantly inhibit fibroblast activity. However, the effect of PDT mediated by the photosensitizer hematoporphyrin monomethyl ether (HMME) on keloids is not known well. The aim of our study was to examine the efficacy of HMME-PDT in cellular and animal models of keloids. Keloid fibroblasts (KFbs) were isolated from human keloid specimens and the proliferation, invasion, and migration of KFbs after HMME-PDT treatment was examined in vitro. Apoptosis in cells was measured by flow cytometry. Cysteinyl aspartate specific proteinase 3 (Caspase3) expression was determined by immunofluorescence staining and western blot. HMME-PDT inhibited KFbs proliferation, invasion, migration, increased apoptosis rate and enhanced caspase3 and cleaved caspase3 expression. The keloid graft transplantation was performed by using nude mice. The growth of the graft was monitored every third day. Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) mRNA expression were detected by quantitative real time PCR. It was observed that HMME-PDT attenuated graft growth and reduced vessel density in the keloid grafts. However, HMME-PDT did not alter IL-6 and TNF-α mRNA expression in the keloid grafts. Moreover, HMME-PDT suppressed transforming growth-β1 (TGF-β1) and small phenotype and Drosophila Mothers Against Decapentaplegic 3 (Smad3) expression in both KFbs and keloid grafts. Collectively, the evidence suggests that HMME-PDT inhibits the growth of the keloid graft by promoting the apoptosis of fibroblasts and reducing vessel formation of the keloid graft.

Raman profile alterations of irradiated human nasopharyngeal cancer cells detected with laser tweezer Raman spectroscopy

Radiotherapy has been widely used for nasopharyngeal carcinoma (NPC) treatment, which causes DNA damage and alterations of macromolecules of cancer cells. However, the Raman profile alterations of irradiated NPC cells remain unclear. In the present study, we used laser tweezers Raman spectroscopy (LTRS) to monitor internal structural changes and chemical modifications in NPC cells after exposure at a clinical dose (2.3 Gy) to X-ray irradiation (IR) at a single-cell level. Two types of NPC cell lines, CNE2 (EBV-negative cell line) and C666-1 (EBV-positive cell line), were used. The Raman spectra of cells before and after radiation treatment were recorded by LTRS. The analysis of spectral differences indicated that the IR caused Raman profile alterations of intracellular proteins, DNA base and lipids. Moreover, by using the multivariate statistical analysis including principal component analysis (PCA) and linear discriminant analysis (LDA) algorithm, an accuracy of 90.0% for classification between CNE2 cells before and after IR could be achieved, which was 10% better than that of C666-1 cells. The results demonstrated that CNE2 cells were more sensitive to IR in comparison to C666-1 cells, providing useful information for creating a treatment strategy in clinical practice. This exploratory study suggested that LTRS combined with multivariate statistical analysis would be a novel and effective tool for evaluating the radiotherapeutic effect on tumor cells, and for detection of the corresponding alterations at the molecular level.

Laser tweezer Raman spectroscopy combined with multivariate statistical analysis was used for evaluating the radiotherapeutic effect on a single tumor cell.

5-aminolevulinic acid mediated photodynamic therapy inhibits survival activity and promotes apoptosis of A375 and A431 cells

OBJECTIVES

The purpose of this study was to investigate the effects of 5-aminolaevulinic acid mediated photodynamic therapy (ALA-PDT) on the survival activity and apoptosis of human melanoma cell line A375 and non-melanoma skin carcinoma cell line A431 cells. The mechanism for cellular apoptosis was explored.

METHODS

The cell survival activity was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and the proportion of apoptotic cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The expression levels of Bcl-2, Bax, caspase-3, caspase-8 and caspase-9 protein were assessed by western blot. The subcellular localization of cytochrome c was comparatively investigated by immunohistochemistry between pre-ALA-PDT and post- ALA-PDT.

RESULTS

ALA-PDT significantly inhibited the survival activity of A375 cells and A431 cells in a dose- and time-dependent manner. The optimum inhibition efficiencies for A375 cells and A431 cells were obtained at 0.6 mM ALA at 4 h and 8 h after ALA-PDT, respectively. The phenomena of apoptosis were observed in ALA-PDT treated cells by TUNEL assay. The apoptotic rates of A375 cells and A431 cells were 90.0% and 61.5% at 6 h after ALA-PDT, respectively. Apoptosis induced by ALA-PDT involved in down-regulation of Bcl-2 protein, up-regulation of Bax protein and cleaved-PARP protein. It was observed that the expression of cleaved- caspase-3, caspase-8 and caspase-9 proteins in A375 cells and A431 cells gradually increased in 2 h and 4 h but decreased at 4-6 h and 6-8 h after ALA-PDT, respectively. In apoptosis cells immunohistochemical localization show that cytochrome C diffused from the mitochondria into the cytosol.

CONCLUSION

ALA-PDT could significantly inhibit the survival activity of A375 and A431 cells. The apoptosis induced by ALA-PDT in A375 and A431 cells was related to the caspase-dependent death-receptor pathway and Cytochrome c-dependent mitochondrial pathway.

Transient spectra study on photo-dynamics of curcumin

A novel mechanism of DNA damage induced by photosensitized curcumin (Cur) was explored using laser flash photolysis, pulse radiolysis and gel electrophoresis. Cur neutral radical (Cur) was confirmed as an identical product in photo-sensitization of Cur by laser flash photolysis and pulse radiolysis. A series of reaction rate constants between Cur and nucleic acid bases/nucleotides were determined by pulse radiolysis. Gel electrophoresis was carried out to investigate damage induced by photosensitized Cur to biologically active DNA. The results indicate that the damage to DNA may be caused by Cur produced from the photosensitization of Cur.

Photodynamic inactivation of Candida albicans by hematoporphyrin monomethyl ether

AIM

To evaluate the capacity of hematoporphyrin monomethyl ether (HMME) in the presence of light to cause photodynamic inactivation (PDI) of Candida albicans.

MATERIALS & METHODS

HMME photoactivity was evaluated against azole-susceptible and -resistant C. albicans. The mechanisms by which PDI of C. albicans occurred were also investigated.

RESULTS

HMME-mediated PACT caused a dose-dependent inactivation of azole-susceptible and -resistant C. albicans. Incubation with 10 μM HMME and irradiation with 72 J cm(-2) light decreased the viability of C. albicans by 7 log10, induced damage of genomic DNA, led to loss of cellular proteins and damaged the cell wall, membrane and intracellular targets.

CONCLUSION

Candida albicans can be effectively inactivated by HMME in the presence of light, and HMME-mediated PACT shows its potential as an antifungal treatment.

Photodynamic inactivation of antibiotic-resistant bacteria and biofilms by hematoporphyrin monomethyl ether

The worldwide increase in bacterial antibiotic resistance has led to a search for alternative antibacterial therapies. A promising approach to killing antibiotic-resistant bacteria is photodynamic antimicrobial chemotherapy, which uses light in combination with a photosensitizer to induce a phototoxic reaction. We evaluated the photodynamic inactivation (PDI) efficiency of hematoporphyrin monomethyl ether (HMME) on antibiotic-resistant bacteria and biofilms. HMME exhibited no significant dark toxicity and provided dose-dependent inactivation of antibiotic-resistant bacteria and biofilms. After incubation with 100-μM HMME and irradiation with 72-J cm(-2) white light, 4.19-7.59 log10 reductions in survival were achieved in planktonic suspension. Antibiotic-resistant strains were as susceptible to PDI in biofilms as in planktonic suspensions, but the inactivation of bacterial cells in biofilms was attenuated. In addition, gram-positive bacterial strains and biofilms were more susceptible than gram-negative strains and biofilms to the PDI effect of HMME. Thus, HMME is a promising photosensitizer for the treatment of infectious diseases caused by antibiotic-resistant bacteria, especially gram-positive bacteria.

Fluorescence visualization screening for EBV-LMP1-targeted DNAzymes

OBJECTIVES

To develop a novel screening method for DNAzymes targeting the LMP1 carboxy region.

STUDY DESIGN

To design a method to screen special DNAzymes toward the Epstein-Barr virus (EBV)-associated carcinoma before clinic use.

SETTING

Key Laboratory of the Ministry of Education-Molecular Biology of Infectious Diseases in Chongqing Medical University.

SUBJECTS AND METHODS

Four novel 10-23 DNAzymes (DZ509, DZ1037, DZ893, and DZ827) targeting the EBV-LMP1 gene were designed and evaluated by detecting enhanced green fluorescence protein (EGFP) expression of LMP1 mRNA and the protein in the nasopharyngeal carcinoma (NPC) cell line CNE2 transfected with the pEGFP-C1-LMP1c vector. The screened specific DNAzymes were then transfected into NPC cell lines C666-1 while a mutant oligonucleotide mutDZ509 and an antisense oligonucleotide ASODN509 were designed as positive and negative controls. Cell proliferation, cell apoptosis, LMP1 mRNA, and the protein were assessed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V-fluorescence isothiocyanate (FITC), reverse transcription polymerase chain reaction (RT-PCR), and Western blots.

RESULTS

The inhibition rates of fluorescence expression of the DNAzymes DZ509, DZ1037, DZ893, and DZ827 were 91.25%, 65.84%, 49.02%, and 44.56%, respectively. The results were in accordance with the inhibition effects of mRNA and protein expression. The screened DZ509 could effectively knock down endogenous LMP1 expression in C666-1 cells, inhibit cell proliferation, and induce cell apoptosis compared with mutDZ509 and ASODN509.

CONCLUSION

LMP1 could present a potential target for DNAzymes toward the EBV-associated carcinoma, and the EGFP expression vector could be a visible method for screening special DNAzymes before clinic use.

Research progress of Hemoporfin--part one: preclinical study

The second generation photosensitizer Hemoporfin (7(12)-(1-methoxyethyl) -12(7)-(1-hydroxyethyl)-3,8,13,17-tetramethyl-21H,23H-porphin-2,18-dipropionic acid) is a porphyrin derivative which processes a stable structure, high singlet oxygen yield, high photoactivity, low dark toxicity and fast clearance rate. Hemoporfin, also known as hematoporphyrin monomethyl ether (HMME) has been studied and used in photodynamic therapy (PDT) in China since 1989. This series of reports will provide an overview on the preclinical and clinical studies of this PDT photosensitizer. The first part of this series will highlight the results of preclinical studies that focused on the compound's optical characteristics, mechanism of the activities, pharmacological and toxicological properties.