-
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 -
Glioma stem-like cells are less susceptible than glioma cells to sonodynamic therapy with photofrin.Technology in Cancer Research &... Dec 2012Despite remarkable progress in diagnosis and treatment, malignant glioma, a highly lethal cancer of the central nervous system, remains incurable. Although glioma...
Despite remarkable progress in diagnosis and treatment, malignant glioma, a highly lethal cancer of the central nervous system, remains incurable. Although glioma stem-like cells (GSCs) represent a relatively small fraction of the cells in malignant glioma, they can proliferate and self renew extensively, being crucial for tumor recurrence. Cancer treatment by sonodynamic therapy (SDT) chiefly depends on antitumor effects of reactive oxygen species (ROS) generated from a sonosensitizer activated by ultrasound. Although SDT effectively kills glioma cells, its efficiency against GSCs is not established. We attempted to compare the susceptibility of GSCs to SDT, using Photofrin, a porphyrin-derivative photosensitizer, with that of glioma cells. Cell viability and apoptosis assays showed that SDT damaged both GSCs and U251 glioma cells, but GSCs were significantly less susceptible to SDT (p < 0.01). To elucidate the mechanism of the antitumor effects of SDT, we evaluated intracellular ROS production and Photofrin uptake: ROS production and Photofrin content were significantly lower (p < 0.01) in GSCs than in U251 glioma cells. Thus, cellular differences in sonosensitizer uptake and ROS production influence the antitumor effects of SDT. Furthermore, the resistance of GSCs may be caused by decreased sonosensitizer uptake due to ABCG2 overexpression.
Topics: ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Survival; Dihematoporphyrin Ether; Glioma; Humans; Neoplasm Proteins; Neoplastic Stem Cells; Reactive Oxygen Species; Sound; Spheroids, Cellular; Tumor Cells, Cultured
PubMed: 22775340
DOI: 10.7785/tcrt.2012.500277 -
PloS One 2012Treatment failure at the primary site after chemoradiotherapy is a major problem in achieving a complete response. Photodynamic therapy (PDT) with porfimer sodium...
BACKGROUND
Treatment failure at the primary site after chemoradiotherapy is a major problem in achieving a complete response. Photodynamic therapy (PDT) with porfimer sodium (Photofrin®) has some problems such as the requirement for shielding from light for several weeks and a high incidence of skin phototoxicity. PDT with talaporfin sodium (Laserphyrin) is less toxic and is expected to have a better effect compared with Photofrin PDT. However, Laserphyrin PDT is not approved for use in the esophagus. In this preclinical study, we investigated tissue damage of the canine normal esophagus caused by photoactivation with Laserphyrin.
METHODOLOGY/PRINCIPAL FINDINGS
Diode laser irradiation was performed at 60 min after administration. An area 5 cm oral to the esophagogastric junction was irradiated at 25 J/cm(2), 50 J/cm(2), and 100 J/cm(2) using a three-step escalation. The irradiated areas were evaluated endoscopically on postirradiation days 1 and 7, and were subjected to histological examination after autopsy. The areas injured by photoactivation were 52 mm(2), 498 mm(2), and 831 mm(2) after irradiation at 25 J/cm(2), 50 J/cm(2), and 100 J/cm(2), respectively. Tissue injury was observed in the muscle layer or even deeper at any irradiation level and became more severe as the irradiation dose increased. At 100 J/cm(2) both inflammatory changes and necrosis were seen histologically in extra-adventitial tissue.
CONCLUSIONS/SIGNIFICANCE
To minimize injury of the normal esophagus by photoactivation with Laserphyrin, diode laser irradiation at 25 J/cm(2) appears to be safe. For human application, it would be desirable to investigate the optimal laser dose starting from this level.
Topics: Animals; Dogs; Drug Evaluation, Preclinical; Esophagus; Photochemotherapy; Photosensitizing Agents; Porphyrins
PubMed: 22719875
DOI: 10.1371/journal.pone.0038308 -
Lasers in Surgery and Medicine Sep 2011Photodynamic therapy (PDT) with porfimer sodium, FDA approved to treat premalignant lesions in Barrett's esophagus, causes photosensitivity for 6-8 weeks. HPPH... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND AND OBJECTIVES
Photodynamic therapy (PDT) with porfimer sodium, FDA approved to treat premalignant lesions in Barrett's esophagus, causes photosensitivity for 6-8 weeks. HPPH (2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a) shows minimal photosensitization of short duration and promising efficacy in preclinical studies. Here we explore toxicity and optimal drug and light dose with endoscopic HPPH-PDT. We also want to know the efficacy of one time treatment with HPPH-PDT.
STUDY DESIGN/MATERIALS AND METHODS
Two nonrandomized dose escalation studies were performed (18 patients each) with biopsy-proven high grade dysplasia or early intramucosal adenocarcinoma of esophagus. HPPH doses ranged from 3 to 6 mg/m2 . At 24 or 48 hours after HPPH administration the lesions received one endoscopic exposure to 150, 175, or 200 J/cm of 665 nm light.
RESULTS
Most patients experienced mild to moderate chest pain requiring symptomatic treatment only. Six patients experienced grade 3 and 4 adverse events (16.6%). Three esophageal strictures were treated with dilatation. No clear pattern of dose dependence of toxicities emerged. In the drug dose ranging study (light dose of 150 J/cm at 48 hours), 3 and 4 mg/m2 of HPPH emerged as most effective. In the light dose ranging study (3 or 4 mg/m2 HPPH, light at 24 hours), complete response rates (disappearance of high grade dysplasia and early carcinoma) of 72% were achieved at 1 year, with all patients treated with 3 mg/m2 HPPH plus 175 J/cm and 4 mg/m2 HPPH plus 150 J/cm showing complete responses at 1 year.
CONCLUSIONS
HPPH-PDT for precancerous lesions in Barrett's esophagus appears to be safe and showing promising efficacy. Further clinical studies are required to establish the use of HPPH-PDT.
Topics: Adenocarcinoma; Aged; Aged, 80 and over; Barrett Esophagus; Chlorophyll; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Drug Administration Schedule; Esophageal Neoplasms; Esophagoscopy; Female; Humans; Infusions, Intravenous; Male; Middle Aged; Photochemotherapy; Photosensitizing Agents; Precancerous Conditions; Treatment Outcome
PubMed: 22057498
DOI: 10.1002/lsm.21112 -
Lasers in Surgery and Medicine Sep 2011Photodynamic therapy (PDT) is an anticancer modality approved for the treatment of early disease and palliation of late stage disease. PDT of tumors results in the...
BACKGROUND AND OBJECTIVE
Photodynamic therapy (PDT) is an anticancer modality approved for the treatment of early disease and palliation of late stage disease. PDT of tumors results in the generation of an acute inflammatory response. The extent and duration of the inflammatory response is dependent upon the PDT regimen employed and is characterized by rapid induction of proinflammatory cytokines, such as IL-6, and activation and mobilization of innate immune cells. The importance of innate immune cells in long-term PDT control of tumor growth has been well defined. In contrast the role of IL-6 in long-term tumor control by PDT is unclear. Previous studies have shown that IL-6 can diminish or have no effect on PDT antitumor efficacy.
STUDY DESIGN/MATERIALS AND METHODS
In the current study we used mice deficient for IL-6, Il6(-/-) , to examine the role of IL-6 in activation of antitumor immunity and PDT efficacy by PDT regimens known to enhance antitumor immunity.
RESULTS
Our studies have shown that elimination of IL-6 had no effect on innate cell mobilization into the treated tumor bed or tumor draining lymph node (TDLN) and did not affect primary antitumor T-cell activation by PDT. However, IL-6 does appear to negatively regulate the generation of antitumor immune memory and PDT efficacy against murine colon and mammary carcinoma models. The inhibition of PDT efficacy by IL-6 appears also to be related to regulation of Bax protein expression. Increased apoptosis was observed following treatment of tumors in Il6(-/-) mice 24 hours following PDT.
CONCLUSIONS
The development of PDT regimens that enhance antitumor immunity has led to proposals for the use of PDT as an adjuvant treatment. However, our results show that the potential for PDT induced expression of IL-6 to enhance tumor survival following PDT must be considered.
Topics: Animals; Apoptosis; Chlorophyll; Colonic Neoplasms; Dihematoporphyrin Ether; Drug Resistance, Neoplasm; Female; Interleukin-6; Lymphocyte Activation; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Neutrophils; Photochemotherapy; Photosensitizing Agents; T-Lymphocytes; bcl-2-Associated X Protein
PubMed: 22057495
DOI: 10.1002/lsm.21107 -
Lasers in Surgery and Medicine Sep 2011A polyphenol constituent of green tea, epigallocatechin gallate (EGCG), has anti-carcinogenic properties. A growing number of studies document EGCG-mediated induction of...
BACKGROUND
A polyphenol constituent of green tea, epigallocatechin gallate (EGCG), has anti-carcinogenic properties. A growing number of studies document EGCG-mediated induction of apoptotic pathways and inhibition of pro-survival factors when combined with chemotherapy or radiation. We evaluated the efficacy of EGCG in modulating photofrin (PH)-mediated photodynamic therapy (PDT) responses.
METHODS
Mouse mammary carcinoma (BA) cells and transplanted BA tumors growing in C3H mice were treated with PH-mediated PDT. Select groups of treated cells and mice also received EGCG and then cytotoxicity, tumor response, and expression of survival molecules were evaluated in all experimental groups.
RESULTS
EGCG increased apoptosis and cytotoxicity in BA cells exposed to PH-mediated PDT. The initial pro-survival phase of the unfolded protein response (UPR), characterized by increased expression of the 78 kDa glucose-regulated protein (GRP-78), was induced by PDT. The second pro-apoptotic phase of the UPR, characterized by phospho-c-Jun N-terminal kinase (p-JNK) expression, activation of caspases-3 and 7, poly ADP ribose polymerase (PARP) cleavage, and expression of C/EBP homologous protein was observed when PDT was combined with EGCG. EGCG also decreased the expression of the pro-survival proteins GRP-78 and survivin, and attenuated PDT-induced prostaglandin E2 (PGE2 ) expression in PDT-treated cells. Comparable responses also were observed when BA tumors were treated with PDT and EGCG. In addition, PDT-induced expression of metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) was down-regulated in treated tumor tissue by EGCG.
CONCLUSIONS
The polyphenol EGCG improves PDT efficacy by increasing tumor apoptosis and decreasing expression of pro-survival and angiogenic molecules within the tumor microenvironment.
Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Blotting, Western; Catechin; Cell Line, Tumor; Dihematoporphyrin Ether; Dinoprostone; Electrophoresis, Polyacrylamide Gel; Endoplasmic Reticulum Chaperone BiP; Female; Heat-Shock Proteins; Inflammation; Mammary Neoplasms, Experimental; Matrix Metalloproteinases, Secreted; Mice; Mice, Inbred C3H; Photochemotherapy; Photosensitizing Agents; Unfolded Protein Response; Vascular Endothelial Growth Factors
PubMed: 22057492
DOI: 10.1002/lsm.21081 -
Cancer Immunology, Immunotherapy : CII Oct 2011Damage-associated molecular patterns (DAMPs), danger signal molecules expressed after injury or infection, have become recognized as prerequisite for orchestrating...
Damage-associated molecular patterns (DAMPs), danger signal molecules expressed after injury or infection, have become recognized as prerequisite for orchestrating effective anti-tumor host response. The expression of two prototypical DAMPs, calreticulin and high-mobility group box-1 (HMGB1) protein, was examined following Photofrin-photodynamic therapy (PDT) of Lewis lung carcinoma (LLC) cells in vitro and LLC tumors growing in syngeneic mice. Cell surface expression of calreticulin was found to be highly increased at 1 h after PDT treatment both in vitro and in vivo. Increased exposure of calreticulin was also detected on the surface of macrophages from PDT-treated LLC tumors. At the same time interval, a rise in serum HMGB1 was detected in host mice. Intracellular staining of macrophages co-incubated for 16 h with PDT-treated LLC cells revealed elevated levels of HMGB1 in these cells. The knowledge of the involvement of these DAMPs uncovers important mechanistic insights into the development of host response induced by PDT.
Topics: Animals; Calreticulin; Carcinoma, Lewis Lung; Cell Separation; Dihematoporphyrin Ether; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; HMGB1 Protein; Mice; Mice, Inbred C57BL; Photochemotherapy; Photosensitizing Agents
PubMed: 21644033
DOI: 10.1007/s00262-011-1047-x -
Lasers in Surgery and Medicine Mar 2011Bacterial arthritis does not respond well to antibiotics and moreover multidrug resistance is spreading. We previously tested photodynamic therapy (PDT) mediated by...
BACKGROUND AND OBJECTIVE
Bacterial arthritis does not respond well to antibiotics and moreover multidrug resistance is spreading. We previously tested photodynamic therapy (PDT) mediated by systemic Photofrin® in a mouse model of methicillin-resistant Staphylococcus aureus (MRSA) arthritis, but found that neutrophils were killed by PDT and therefore the infection was potentiated.
STUDY DESIGN/MATERIALS AND METHODS
The present study used an intra-articular injection of Photofrin® and optimized the light dosimetry in order to maximize bacterial killing and minimize killing of host neutrophils. MRSA (5 × 10(7) CFU) was injected into the mouse knee followed 3 days later by 1 µg of Photofrin® and 635-nm diode laser illumination with a range of fluences within 5 minutes. Synovial fluid was sampled 6 hours or 1-3, 5, and 7 days after PDT to determine MRSA colony-forming units (CFU), neutrophil numbers, and levels of cytokines.
RESULTS
A biphasic light dose response was observed with the greatest reduction of MRSA CFU seen with a fluence of 20 J cm(-2), whereas lower antibacterial efficacy was observed with fluences that were either lower or higher. Consistent with these results, a significantly higher concentration of macrophage inflammatory protein-2, a CXC chemokine, and greater accumulation of neutrophils were seen in the infected knee joint after PDT with a fluence of 20 J cm(-2) compared to fluences of 5 or 70 J cm(-2).
CONCLUSION
PDT for murine MRSA arthritis requires appropriate light dosimetry to simultaneously maximize bacterial killing and neutrophil accumulation into the infected site, while too little light does not kill sufficient bacteria and too much light kills neutrophils and damages host tissue as well as bacteria and allows bacteria to grow unimpeded by host defense.
Topics: Animals; Arthritis, Experimental; Arthritis, Infectious; Dihematoporphyrin Ether; Dose-Response Relationship, Radiation; Drug Administration Schedule; Hematoporphyrin Photoradiation; Injections, Intra-Articular; Knee Joint; Lasers, Semiconductor; Leukocytes; Male; Methicillin-Resistant Staphylococcus aureus; Mice; Mice, Inbred C57BL; Neutrophils; Photosensitizing Agents; Staphylococcal Infections; Synovial Fluid
PubMed: 21412806
DOI: 10.1002/lsm.21037 -
Photochemical & Photobiological... Jun 2011Biological oxygen measurements by phosphorescence quenching make use of exogenous phosphorescent probes, which are introduced directly into the medium of interest (e.g....
Biological oxygen measurements by phosphorescence quenching make use of exogenous phosphorescent probes, which are introduced directly into the medium of interest (e.g. blood or interstitial fluid) where they serve as molecular sensors for oxygen. The byproduct of the quenching reaction is singlet oxygen, a highly reactive species capable of damaging biological tissue. Consequently, potential probe phototoxicity is a concern for biological applications. Herein, we compared the ability of polyethyleneglycol (PEG)-coated Pd tetrabenzoporphyrin (PdTBP)-based dendritic nanoprobes of three successive generations to sensitize singlet oxygen. It was found that the size of the dendrimer has practically no effect on the singlet oxygen sensitization efficiency in spite of the strong attenuation of the triplet quenching rate with an increase in the dendrimer generation. This unexpected result is due to the fact that the lifetime of the PdTBP triplet state in the absence of oxygen increases with dendritic generation, thus compensating for the concomitant decrease in the rate of quenching. Nevertheless, in spite of their ability to sensitize singlet oxygen, the phosphorescent probes were found to be non-phototoxic when compared with the commonly used photodynamic drug Photofrin in a standard cell-survival assay. The lack of phototoxicity is presumably due to the inability of PEGylated probes to associate with cell surfaces and/or penetrate cellular membranes. In contrast, conventional photosensitizers bind to cell components and act by generating singlet oxygen inside or in the immediate vicinity of cellular organelles. Therefore, PEGylated dendritic probes are safe to use for tissue oxygen measurements as long as the light doses are less than or equal to those commonly employed in photodynamic therapy.
Topics: Animals; Cell Line, Tumor; Dendrimers; Dihematoporphyrin Ether; Light; Luminescent Agents; Mice; Oxygen; Palladium; Polyethylene Glycols; Porphyrins; Singlet Oxygen; Spectrometry, Fluorescence
PubMed: 21409208
DOI: 10.1039/c0pp00356e -
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