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British Journal of Cancer Jul 2010Photodynamic therapy (PDT) is a promising adjuvant therapy in cancer treatment. However, cancers resistant to PDT, mediated through the efflux of photosensitisers by...
BACKGROUND
Photodynamic therapy (PDT) is a promising adjuvant therapy in cancer treatment. However, cancers resistant to PDT, mediated through the efflux of photosensitisers by means of P-glycoprotein or ATP-binding cassette transporter proteins, have been reported. The DNA repair has also been suggested to be responsible for PDT resistance, but little is known about the repair pathways and mechanisms involved. Therefore, this study aimed to investigate the possible function of six major DNA repair mechanisms in glioma cells resistant to Photofrin-mediated PDT (Ph-PDT).
METHODS
The U87 glioma cells relatively resistant to Ph-PDT were obtained by recovering the viable cells 3 h after PDT treatment. The mRNA and protein expression levels of DNA repair genes were evaluated by quantitative real-time reverse transcription-polymerase chain reaction and western blotting, respectively. Small-interfering RNA and chromatin-immunoprecipitation assays were used to further examine the relationship between AlkB, an alkylation repair homologue 2 (Escherichia coli) (ALKBH2) and Ph-PDT responsiveness, and transcription factors involved in ALKBH2 transcription.
RESULTS
The ALKBH2 of DNA damage reversal was significantly increased at both mRNA and protein levels from 30 min to 48 h post-treatment with Ph-PDT. Conversely, down-regulating ALKBH2 expression enhances Ph-PDT efficiency. Furthermore, our data clearly show for the first time that tumour protein (TP53) is directly involved by binding to the promoter of ALKBH2 in mediating Ph-PDT resistance.
CONCLUSION
C The DNA damage reversal mechanisms may have important functions in Ph-PDT resistance through the activation of ALKBH2 by TP53.
Topics: AlkB Homolog 2, Alpha-Ketoglutarate-Dependent Dioxygenase; Blotting, Western; Cell Line, Tumor; Cell Survival; Comet Assay; DNA Damage; DNA Repair Enzymes; Dihematoporphyrin Ether; Dioxygenases; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Glioblastoma; Glioma; Humans; Kinetics; Photochemotherapy; RNA, Messenger; Reverse Transcriptase Polymerase Chain Reaction; Transcription, Genetic; Transfection; Tumor Suppressor Protein p53
PubMed: 20661249
DOI: 10.1038/sj.bjc.6605797 -
Oncogene Jun 2006Photodynamic therapy is a promising antitumor treatment modality approved for the management of both early and advanced tumors. The mechanisms of its antitumor action...
Photodynamic therapy is a promising antitumor treatment modality approved for the management of both early and advanced tumors. The mechanisms of its antitumor action include generation of singlet oxygen and reactive oxygen species that directly damage tumor cells and tumor vasculature. A number of mechanisms seem to be involved in the protective responses to PDT that include activation of transcription factors, heat shock proteins, antioxidant enzymes and antiapoptotic pathways. Elucidation of these mechanisms might result in the design of more effective combination strategies to improve the antitumor efficacy of PDT. Using DNA microarray analysis to identify stress-related genes induced by Photofrin-mediated PDT in colon adenocarcinoma C-26 cells, we observed a marked induction of heme oxygenase-1 (HO-1). Induction of HO-1 with hemin or stable transfection of C-26 with a plasmid vector encoding HO-1 increased resistance of tumor cells to PDT-mediated cytotoxicity. On the other hand, zinc (II) protoporphyrin IX, an HO-1 inhibitor, markedly augmented PDT-mediated cytotoxicity towards C-26 and human ovarian carcinoma MDAH2774 cells. Neither bilirubin, biliverdin nor carbon monoxide, direct products of HO-1 catalysed heme degradation, was responsible for cytoprotection. Importantly, desferrioxamine, a potent iron chelator significantly potentiated cytotoxic effects of PDT. Altogether our results indicate that HO-1 is involved in an important protective mechanism against PDT-mediated phototoxicity and administration of HO-1 inhibitors might be an effective way to potentiate antitumor effectiveness of PDT.
Topics: Animals; Carbon Monoxide; Chelating Agents; Dihematoporphyrin Ether; Heme; Heme Oxygenase-1; Humans; Iron; Mice; Neoplasms; Oligonucleotide Array Sequence Analysis; Oxygen; Photochemotherapy; Reactive Oxygen Species
PubMed: 16462769
DOI: 10.1038/sj.onc.1209378 -
Antimicrobial Agents and Chemotherapy Oct 2005Treatment of mucocutaneous and cutaneous Candida albicans infections with photosensitizing agents and light, termed photodynamic therapy (PDT), offers an alternative to... (Comparative Study)
Comparative Study
Treatment of mucocutaneous and cutaneous Candida albicans infections with photosensitizing agents and light, termed photodynamic therapy (PDT), offers an alternative to conventional treatments. Initial studies using the clinically approved photosensitizer Photofrin demonstrated the susceptibility of C. albicans to its photodynamic effects. In the present study, we have further refined parameters for Photofrin-mediated photodynamic action against C. albicans and examined whether mechanisms commonly used by microorganisms to subvert either antimicrobial oxidative defenses or antimicrobial therapy, including biofilm formation, were operative. In buffer and defined medium, germ tubes preloaded with Photofrin retained their photosensitivity for up to 2 hours, indicating the absence of degradation or export of Photofrin by the organism. The addition of serum resulted in a gradual loss of photosensitivity over 2 hours. In contrast to an adaptive response by germ tubes to oxidative stress by hydrogen peroxide, there was no adaptive response to singlet oxygen-mediated stress by photodynamic action. C. albicans biofilms were sensitive to Photofrin-mediated phototoxicity in a dose-dependent manner. Finally, the metabolic activity of C. albicans biofilms following photodynamic insult was significantly lower than that of biofilms treated with amphotericin B for the same time period. These results demonstrate that several of the mechanisms microorganisms use to subvert either antimicrobial oxidative defenses or antimicrobial therapy are apparently not operative during Photofrin-mediated photodynamic treatment of C. albicans. These observations provide support and rationale for the continued investigation of PDT as an adjunctive, or possibly alternative, mode of therapy against cutaneous and mucocutaneous candidiasis.
Topics: Amphotericin B; Antifungal Agents; Biofilms; Candida albicans; Culture Media; Dermatitis, Phototoxic; Dihematoporphyrin Ether; Dose-Response Relationship, Radiation; Hydrogen Peroxide; Kinetics; Microscopy, Fluorescence; Oxidants; Photochemotherapy; Photosensitizing Agents
PubMed: 16189110
DOI: 10.1128/AAC.49.10.4288-4295.2005 -
Cell Death & Disease Jul 2012Diverse death phenotypes of cancer cells can be induced by Photofrin-mediated photodynamic therapy (PDT), which has a decisive role in eliciting a tumor-specific...
Diverse death phenotypes of cancer cells can be induced by Photofrin-mediated photodynamic therapy (PDT), which has a decisive role in eliciting a tumor-specific immunity for long-term tumor control. However, the mechanism(s) underlying this diversity remain elusive. Caspase-3 is a critical factor in determining cell death phenotypes in many physiological settings. Here, we report that Photofrin-PDT can modify and inactivate procaspase-3 in cancer cells. In cells exposed to an external apoptotic trigger, high-dose Photofrin-PDT pretreatment blocked the proteolytic activation of procaspase-3 by its upstream caspase. We generated and purified recombinant procaspase-3-D(3)A (a mutant without autolysis/autoactivation activity) to explore the underlying mechanism(s). Photofrin could bind directly to procaspase-3-D(3)A, and Photofrin-PDT-triggered inactivation and modification of procaspase-3-D(3)A was seen in vitro. Mass spectrometry-based quantitative analysis for post-translational modifications using both (16)O/(18)O- and (14)N/(15)N-labeling strategies revealed that Photofrin-PDT triggered a significant oxidation of procaspase-3-D(3)A (mainly on Met-27, -39 and -44) in a Photofrin dose-dependent manner, whereas the active site Cys-163 remained largely unmodified. Site-directed mutagenesis experiments further showed that Met-44 has an important role in procaspase-3 activation. Collectively, our results reveal that Met oxidation is a novel mechanism for the Photofrin-PDT-mediated inactivation of procaspase-3, potentially explaining at least some of the complicated cell death phenotypes triggered by PDT.
Topics: Amino Acid Sequence; Apoptosis; Caspase 3; Catalytic Domain; Cell Line, Tumor; Dihematoporphyrin Ether; Humans; Jurkat Cells; Methionine; Molecular Sequence Data; Mutagenesis, Site-Directed; Neoplasms; Nitrogen Isotopes; Oxidation-Reduction; Oxygen Isotopes; Photochemotherapy; Photosensitizing Agents; Protein Binding; Protein Processing, Post-Translational; Recombinant Proteins; Tandem Mass Spectrometry; Ultraviolet Rays
PubMed: 22785533
DOI: 10.1038/cddis.2012.85 -
Photodiagnosis and Photodynamic Therapy Mar 2011Photodynamic therapy (PDT) has been used for head and neck carcinomas with little experience in the oropharynx due to technical challenges in achieving adequate...
Photodynamic therapy (PDT) has been used for head and neck carcinomas with little experience in the oropharynx due to technical challenges in achieving adequate exposure. We present the case of a patient with a second right tonsil carcinoma following previous treatment with transoral robotic surgery (TORS) and postoperative chemoradiation for a left tonsil carcinoma. Repeat TORS for the right tonsil carcinoma reviewed multiple positive surgical margins. The power output from the robotic camera was modified to facilitate safe intraoperative three dimensional visualization of the tumor bed. The robotic arms facilitated clear exposure of the tonsil and tongue base with stable administration of the fluence. Real-time measurements confirmed stable photobleaching with augmentation of the prescribed light fluence secondary to light scatter in the oropharynx. We report a potential new role using TORS for exposure and accurate PDT in the oropharynx.
Topics: Administration, Oral; Dihematoporphyrin Ether; Drug Therapy, Computer-Assisted; Humans; Male; Middle Aged; Photochemotherapy; Photosensitizing Agents; Robotics; Tonsillar Neoplasms; Treatment Outcome
PubMed: 21333937
DOI: 10.1016/j.pdpdt.2010.12.005 -
Journal of Biomedical Optics Oct 2013We demonstrate the use of an enzyme-activatable fluorogenic probe, Neutrophil Elastase 680 FAST (NE680), for in vivo imaging of neutrophil elastase (NE) activity in...
We demonstrate the use of an enzyme-activatable fluorogenic probe, Neutrophil Elastase 680 FAST (NE680), for in vivo imaging of neutrophil elastase (NE) activity in tumors subjected to photodynamic therapy (PDT). NE protease activity was assayed in SCC VII and EMT6 tumors established in C3H and BALB/c mice, respectively. Four nanomoles of NE680 was injected intravenously immediately following PDT irradiation. 5 h following administration of NE680, whole-mouse fluorescence imaging was performed. At this time point, levels of NE680 fluorescence were at least threefold greater in irradiated versus unirradiated SCC VII and EMT6 tumors sensitized with Photofrin. To compare possible photosensitizer-specific differences in therapy-induced elastase activity, EMT6 tumors were also subjected to 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH)-PDT. NE levels measured in HPPH-PDT-treated tumors were twofold higher than in unirradiated controls. Ex vivo labeling of host cells using fluorophore-conjugated antibodies and confocal imaging were used to visualize Gr1+ cells in Photofrin-PDT-treated EMT6 tumors. These data were compared with recently reported analysis of Gr1+ cell accumulation in EMT6 tumors subjected to HPPH-PDT. The population density of infiltrating Gr1+ cells in treated versus unirradiated drug-only control tumors suggests that the differential in NE680 fold enhancement observed in Photofrin versus HPPH treatment may be attributed to the significantly increased inflammatory response induced by Photofrin-PDT. The in vivo imaging of NE680, which is a fluorescent reporter of NE extracellular release caused by neutrophil activation, demonstrates that PDT results in increased NE levels in treated tumors, and the accumulation of the cleaved probe tracks qualitatively with the intratumor Gr1+ cell population.
Topics: Animals; Dihematoporphyrin Ether; Female; Fluorescent Dyes; Leukocyte Elastase; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Molecular Imaging; Optical Imaging; Photochemotherapy; Photosensitizing Agents
PubMed: 23897439
DOI: 10.1117/1.JBO.18.10.101314 -
British Journal of Cancer Feb 1996Photofrin accumulation in malignant and host cell populations of various tumours was studied by flow cytometry analysis of cells dissociated from the tumour tissue. The... (Comparative Study)
Comparative Study
Photofrin accumulation in malignant and host cell populations of various tumours was studied by flow cytometry analysis of cells dissociated from the tumour tissue. The transplantable mouse tumour models included in this analysis were sarcomas EMT6, RIF, KHT and FsaN, Lewis lung carcinoma, SCCVII squamous cell carcinoma (SCC) and slowly growing moderately differentiated AT17 SCC. An example of spontaneous mouse adenocarcinoma was also examined. Staining with specific monoclonal antibodies was used to identify the various cell populations present in these tumours. The main characteristic of Photofrin cellular accumulation was a very high photosensitiser content found exclusively in a subpopulation of tumour-associated macrophages (TAMs). Photosensitiser levels similar to or lower than in malignant cells were observed in the remaining TAMs and other tumour-infiltrating host cells. Photofrin accumulation in malignant cells was not equal in all tumour models, but may have been affected by tumour blood perfusion/vascularisation. Results consistent with the above findings were obtained with SCC of buccal mucosa induced by 9,10-dimethyl-1,2-benzanthracene in Syrian hamsters. The TAM subpopulation that accumulates by far the highest cellular Photofrin levels in tumours is suggested to be responsible for the tumour-localised photosensitiser fluorescence.
Topics: Animals; Antineoplastic Agents; Cricetinae; Dihematoporphyrin Ether; Female; Fibrosarcoma; Lung Neoplasms; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mouth Mucosa; Myocardium; Sarcoma, Experimental; Tissue Distribution
PubMed: 8595166
DOI: 10.1038/bjc.1996.88 -
Cancer Immunology, Immunotherapy : CII Mar 2015Effective therapy for advanced cancer often requires treatment of both primary tumors and systemic disease that may not be apparent at initial diagnosis. Numerous...
Effective therapy for advanced cancer often requires treatment of both primary tumors and systemic disease that may not be apparent at initial diagnosis. Numerous studies have shown that stimulation of the host immune system can result in the generation of anti-tumor immune responses capable of controlling metastatic tumor growth. Thus, there is interest in the development of combination therapies that both control primary tumor growth and stimulate anti-tumor immunity for control of metastatic disease and subsequent tumor growth. Photodynamic therapy (PDT) is an FDA-approved anticancer modality that has been shown to enhance anti-tumor immunity. Augmentation of anti-tumor immunity by PDT is regimen dependent, and PDT regimens that enhance anti-tumor immunity have been defined. Unfortunately, these regimens have limited ability to control primary tumor growth. Therefore, a two-step combination therapy was devised in which a tumor-controlling PDT regimen was combined with an immune-enhancing PDT regimen. To determine whether the two-step combination therapy enhanced anti-tumor immunity, resistance to subsequent tumor challenge and T cell activation and function was measured. The ability to control distant disease was also determined. The results showed that the novel combination therapy stimulated anti-tumor immunity while retaining the ability to inhibit primary tumor growth of both murine colon (Colon26-HA) and mammary (4T1) carcinomas. The combination therapy resulted in enhanced tumor-specific T cell activation and controlled metastatic tumor growth. These results suggest that PDT may be an effective adjuvant for therapies that fail to stimulate the host anti-tumor immune response.
Topics: Animals; Antineoplastic Agents; Chlorophyll; Colonic Neoplasms; Dihematoporphyrin Ether; Female; Lymphocyte Activation; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Neoplasm Metastasis; Photochemotherapy; Photosensitizing Agents; Random Allocation; T-Lymphocytes; Transfection
PubMed: 25384911
DOI: 10.1007/s00262-014-1633-9 -
The European Respiratory Journal Oct 1999A prospective controlled randomized trial was performed in order to assess the effectiveness and safety of photodynamic therapy versus laser resection in 31 patients... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
A prospective controlled randomized trial was performed in order to assess the effectiveness and safety of photodynamic therapy versus laser resection in 31 patients with partial or complete tracheobronchial obstruction due to inoperable non-small cell lung cancer. Fourteen patients received dihaematoporphyrin ether and argon dye laser photoradiation, and 17 patients received Nd-YAG laser resection. Endoluminal obstruction of >75% was found in 77.4% of the patients. Among the symptoms, cough was more severe in the Nd-YAG group (p=0.02). Patients in both groups experienced symptomatic relief after treatment (p=0.003). Patients in the photodynamic therapy (PDT) group showed a significantly longer time until treatment failure (p=0.03) and longer median survival (p=0.007). Bronchitis and photosensitization (both in the PDT group) were the most common adverse effects. There was one death, probably related to treatment, in the PDT group. Photodynamic therapy and neodymium-yttrium aluminium garnet laser resection showed similar effectiveness and safety in the palliation of symptoms. The more prolonged survival in the photodynamic therapy group may have been due to differences in tumour stage between the groups. The degree of obstruction improved after treatment in both groups. In conclusion, photodynamic therapy is a valid method of palliation in partially or totally obstructing non-small cell lung carcinoma.
Topics: Aged; Airway Obstruction; Antineoplastic Agents; Biopsy; Bronchoscopy; Carcinoma, Non-Small-Cell Lung; Dihematoporphyrin Ether; Follow-Up Studies; Humans; Laser Therapy; Lung Neoplasms; Middle Aged; Palliative Care; Photochemotherapy; Prospective Studies; Safety; Treatment Outcome
PubMed: 10573224
DOI: 10.1034/j.1399-3003.1999.14d13.x -
Photochemical & Photobiological... Dec 2009Photodynamic therapy (PDT) can lead to the creation of heterogeneous, response-limiting hypoxia during illumination, which may be controlled in part through illumination...
Photodynamic therapy (PDT) can lead to the creation of heterogeneous, response-limiting hypoxia during illumination, which may be controlled in part through illumination fluence rate. In the present report we consider (1) regional differences in hypoxia, vascular response, and cell kill as a function of tumor depth and (2) the role of fluence rate as a mediator of depth-dependent regional intratumor heterogeneity. Intradermal RIF murine tumors were treated with Photofrin PDT using surface illumination at an irradiance of 75 or 38 mW cm(-2). Regional heterogeneity in tumor response was examined through comparison of effects in the surface vs. base of tumors, i.e. along a plane parallel to the skin surface and perpendicular to the incident illumination. 75 mW cm(-2) PDT created significantly greater hypoxia in tumor bases relative to their surfaces. Increased hypoxia in the tumor base could not be attributed to regional differences in Photofrin concentration nor effects of fluence rate distribution on photochemical oxygen consumption, but significant depth-dependent heterogeneity in vascular responses and cytotoxic response were detected. At a lower fluence rate of 38 mW cm(-2), no detectable regional differences in hypoxia or cytotoxic responses were apparent, and heterogeneity in vascular response was significantly less than that during 75 mW cm(-2) PDT. This research suggests that the benefits of low-fluence-rate PDT are mediated in part by a reduction in intratumor heterogeneity in hypoxic, vascular and cytotoxic responses.
Topics: Animals; Cell Hypoxia; Dihematoporphyrin Ether; Fibrosarcoma; Light; Mice; Mice, Inbred C3H; Neoplasms, Radiation-Induced; Nitroimidazoles; Photochemotherapy; Photosensitizing Agents
PubMed: 20024165
DOI: 10.1039/b9pp00004f