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Elzi DJ, Bauta WE, Sanchez JR, Das T, Mogare S, Zannes Fatland P, Iza M, Pertsemlidis A, Rebel VI. Identification of a novel mechanism for meso-tetra (4-carboxyphenyl) porphyrin (TCPP) uptake in cancer cells. FASEB J 2021; 35:e21427. [PMID: 33629776 DOI: 10.1096/fj.202000197r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 01/13/2021] [Accepted: 01/22/2021] [Indexed: 01/23/2023]
Abstract
Porphyrins are used for cancer diagnostic and therapeutic applications, but the mechanism of how porphyrins accumulate in cancer cells remains elusive. Knowledge of how porphyrins enter cancer cells can aid the development of more accurate cancer diagnostics and therapeutics. To gain insight into porphyrin uptake mechanisms in cancer cells, we developed a flow cytometry assay to quantify cellular uptake of meso-tetra (4-carboxyphenyl) porphyrin (TCPP), a porphyrin that is currently being developed for cancer diagnostics. We found that TCPP enters cancer cells through clathrin-mediated endocytosis. The LDL receptor, previously implicated in the cellular uptake of other porphyrins, only contributes modestly to uptake. We report that TCPP instead binds strongly ( K D = 42 nM ) to CD320, the cellular receptor for cobalamin/transcobalamin II (Cbl/TCN2). Additionally, TCPP competes with Cbl/TCN2 for CD320 binding, suggesting that CD320 is a novel receptor for TCPP. Knockdown of CD320 inhibits TCPP uptake by up to 40% in multiple cancer cell lines, including lung, breast, and prostate cell lines, which supports our hypothesis that CD320 both binds to and transports TCPP into cancer cells. Our findings provide some novel insights into why porphyrins concentrate in cancer cells. Additionally, our study describes a novel function for the CD320 receptor which has been reported to transport only Cbl/TCN2 complexes.
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Affiliation(s)
- David J Elzi
- BioAffinity Technologies, Inc., San Antonio, TX, USA
| | | | | | - Trisha Das
- BioAffinity Technologies, Inc., San Antonio, TX, USA
| | - Shweta Mogare
- BioAffinity Technologies, Inc., San Antonio, TX, USA
| | | | - Moises Iza
- BioAffinity Technologies, Inc., San Antonio, TX, USA
| | - Alexander Pertsemlidis
- Department of Pediatrics, The University of Texas Health Science Center, San Antonio, TX, USA.,Department of Cell Systems & Anatomy, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Greehey Children's Cancer Research Institute, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Mays Cancer Center, UT Health San Antonio MD Anderson, San Antonio, TX, USA
| | - Vivienne I Rebel
- BioAffinity Technologies, Inc., San Antonio, TX, USA.,Department of Cell Systems & Anatomy, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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2
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Faustova M, Nikolskaya E, Sokol M, Fomicheva M, Petrov R, Yabbarov N. Metalloporphyrins in Medicine: From History to Recent Trends. ACS APPLIED BIO MATERIALS 2020; 3:8146-8171. [PMID: 35019597 DOI: 10.1021/acsabm.0c00941] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The history of metalloporphyrins dates back more than 200 years ago. Metalloporphyrins are excellent catalysts, capable of forming supramolecular systems, participate in oxygen photosynthesis, transport, and used as contrast agents or superoxide dismutase mimetics. Today, metalloporphyrins represent complexes of conjugated π-electron system and metals from the entire periodic system. However, the effect of these compounds on living systems has not been fully understood, and researchers are exploring the properties of metalloporphyrins thereby extending their further application. This review provides an overview of the variety of metalloporphyrins that are currently used in different medicine fields and how metalloporphyrins became the subject of scientists' interest. Currently, metalloporphyrins utilization has expanded significantly, which gave us an opprotunuty to summarize recent progress in metalloporphyrins derivatives and prospects of their application in the treatment and diagnosis of different diseases.
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Affiliation(s)
- Mariia Faustova
- MIREA-Russian Technological University, Lomonosov Institute of Fine Chemical Technologies, 119454 Moscow, Russia.,N. M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119991 Moscow, Russia
| | - Elena Nikolskaya
- N. M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119991 Moscow, Russia
| | - Maria Sokol
- N. M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119991 Moscow, Russia.,JSC Russian Research Center for Molecular Diagnostics and Therapy, 117149 Moscow Russia
| | - Margarita Fomicheva
- N. M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119991 Moscow, Russia.,JSC Russian Research Center for Molecular Diagnostics and Therapy, 117149 Moscow Russia
| | - Rem Petrov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia
| | - Nikita Yabbarov
- N. M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119991 Moscow, Russia.,JSC Russian Research Center for Molecular Diagnostics and Therapy, 117149 Moscow Russia
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3
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Renfrew AK, Karges J, Scopelliti R, Bobbink FD, Nowak‐Sliwinska P, Gasser G, Dyson PJ. Towards Light‐Activated Ruthenium–Arene (RAPTA‐Type) Prodrug Candidates. Chembiochem 2019; 20:2876-2882. [DOI: 10.1002/cbic.201900236] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Anna K. Renfrew
- Institut des Sciences et Ingénierie ChimiquesEcole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Johannes Karges
- Chimie ParisTechPSL UniversityCNRSInstitute of Chemistry for Life and Health SciencesLaboratory for Inorganic Chemical Biology 75005 Paris France
| | - Rosario Scopelliti
- Institut des Sciences et Ingénierie ChimiquesEcole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Felix D. Bobbink
- Institut des Sciences et Ingénierie ChimiquesEcole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Patrycja Nowak‐Sliwinska
- Institute of Pharmaceutical Sciences of Western Switzerland andTranslational Research Center in Oncohaematology 1211 Geneva 4 Switzerland
| | - Gilles Gasser
- Chimie ParisTechPSL UniversityCNRSInstitute of Chemistry for Life and Health SciencesLaboratory for Inorganic Chemical Biology 75005 Paris France
| | - Paul J. Dyson
- Institut des Sciences et Ingénierie ChimiquesEcole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
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Comparison of light-induced formation of reactive oxygen species and the membrane destruction of two mesoporphyrin derivatives in liposomes. Sci Rep 2019; 9:11312. [PMID: 31383921 PMCID: PMC6683201 DOI: 10.1038/s41598-019-47841-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 07/18/2019] [Indexed: 11/13/2022] Open
Abstract
The photodynamic effect requires the simultaneous presence of light, photosensitizer (PS) and molecular oxygen. In this process, the photoinduced damage of cells is caused by reactive oxygen species (ROS). Besides DNA, the other target of ROS is the membranes, separating internal compartments in living cells. Hence, the ability of ROS formation of porphyrins as PSs, in liposomes as simple models of cellular membranes is of outstanding interest. Earlier we compared the binding parameters and locations of mesoporphyrin IX dihydrochloride (MPCl) and mesoporphyrin IX dimethyl ester (MPE), in small unilamellar vesicles (SUV) made from various saturated phosphatidylcholines. In this study, we used the same kinds of samples for comparing the ROS forming ability. Triiodide production from potassium iodide because of light-induced ROS in the presence of molybdate catalyst was applied, and the amount of product was quantitatively followed by optical spectrometry. Furthermore, we demonstrated and carefully studied SUVs disruption as direct evidence of membrane destruction by the methods of dynamic light scattering (DLS) and fluorescence correlation spectroscopy (FCS), applying unsaturated phosphatidylcholines as membrane components. Although the ROS forming ability is more pronounced in the case of MPCl, we found that the measured disruption was more effective in the samples containing MPE.
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de Albuquerque IO, Nunes J, Figueiró Longo JP, Muehlmann LA, Azevedo RB. Photodynamic therapy in superficial basal cell carcinoma treatment. Photodiagnosis Photodyn Ther 2019; 27:428-432. [PMID: 31349099 DOI: 10.1016/j.pdpdt.2019.07.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 07/11/2019] [Accepted: 07/22/2019] [Indexed: 12/30/2022]
Abstract
Basal cell cancer (BCC) is an epithelial neoplasm that arises from basal cells, which constitute the lower layer of the epidermis. Global statistics have shown the progressive increase in the incidence of skin cancer in several countries. The cumulative exposure to solar radiation (ultraviolet B) in the first two decades of life represents the critical risk for the disease. Preclinical and clinical trials have shown photodynamic therapy (PDT) as a promising innovation for treatment of skin cancers, especially to the non-melanoma group. The authors reviewed trials with photodynamic therapy in superficial basal cell carcinoma with different photosensitizers to better evaluate how PDT modifies the natural history of sBCC. We conclude trials should not assess only the immediate efficacy but the main goal of long-term effectiveness of the protocols in order to generate best evidence for clinical practice.
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Affiliation(s)
- Itajaí Oliveira de Albuquerque
- Laboratory of Nanobiotechnology, Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasília, Brasília DF, Brazil
| | - João Nunes
- Service of Clinical Oncology, University Hospital of Brasília (HUB), Brazil
| | - João Paulo Figueiró Longo
- Laboratory of Nanobiotechnology, Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasília, Brasília DF, Brazil
| | - Luis Alexandre Muehlmann
- Laboratory of Nanobiotechnology, Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasília, Brasília DF, Brazil
| | - Ricardo Bentes Azevedo
- Laboratory of Nanobiotechnology, Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasília, Brasília DF, Brazil.
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6
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Mari C, Pierroz V, Leonidova A, Ferrari S, Gasser G. Towards Selective Light-Activated RuII-Based Prodrug Candidates. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500602] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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7
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Kessel D, Reiners JJ. Promotion of Proapoptotic Signals by Lysosomal Photodamage. Photochem Photobiol 2015; 91:931-6. [PMID: 25873082 DOI: 10.1111/php.12456] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/26/2015] [Indexed: 01/21/2023]
Abstract
We previously reported that low-level lysosomal photodamage enhanced the efficacy of subsequent mitochondrial photodamage, resulting in a substantial promotion of apoptotic cell death. We now extend our analysis of the sequential PDT protocol to include two additional lysosomal-targeting photosensitizers. These agents, because of enhanced permeability, are more potent than the agent (N-aspartyl chlorin E6, NPe6) used in the initial study. Addition of the cell-permeable cysteine protease inhibitor E-64d and calcium chelator BAPTA-AM almost completely suppressed sequential PDT-induced loss of mitochondrial membrane potential and activation of procaspases-3 and -7. These inhibitors did not, however, suppress the proapoptotic effect of a BH3 mimetic or mitochondrial photodamage. Knockdowns of ATG7 or ATG5, proteins normally associated with autophagy, suppressed photodamage induced by the sequential PDT protocol. These effects appear to be independent of the autophagic process as pharmacological inhibition of autophagy offered no such protection. Effects of ATG7 and ATG5 knockdowns may reflect the role that ATG7 plays in regulating lysosome permeability, and the likelihood that a proteolytic fragment of ATG5 amplifies mitochondrial proapoptotic processes. Our results suggest that low-dose photodamage that sequentially targets lysosomes and mitochondria may offer significant advantages over the use of single photosensitizers.
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Affiliation(s)
- David Kessel
- Department of Pharmacology, Wayne State University, Detroit, MI
| | - John J Reiners
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI
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Wang X, Hu J, Wang P, Zhang S, Liu Y, Xiong W, Liu Q. Analysis of the in vivo and in vitro effects of photodynamic therapy on breast cancer by using a sensitizer, sinoporphyrin sodium. Theranostics 2015; 5:772-86. [PMID: 25897341 PMCID: PMC4402500 DOI: 10.7150/thno.10853] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 03/06/2015] [Indexed: 12/21/2022] Open
Abstract
Photodynamic therapy (PDT) is an emerging theranostic modality for various cancers and diseases. Photosensitizers are critical components for PDT. Sinoporphyrin sodium, referred to as DVDMS, is a newly identified photosensitizer that was isolated from Photofrin. Here, we evaluated the effects of DVDMS-mediated PDT (DVDMS-PDT) on tumor cell proliferation and metastasis in the highly metastatic 4T1 cell line and a mouse xenograft model. DVDMS-PDT elicited a potent phototoxic effect in vitro, which was abolished using the reactive oxygen species (ROS) scavenger N-acetylcysteine. In addition, DVDMS-PDT effectively inhibited the migration of 4T1 cells in scratch wound-healing and transwell assays. Using an in vivo mouse model, DVDMS-PDT greatly prolonged the survival time of tumor-bearing mice and inhibited tumor growth and lung metastasis, consistent with in vitro findings. PDT with DVDMS had a greater anti-tumor efficacy than clinically used Photofrin. Moreover, preliminary toxicological results indicate that DVDMS is relatively safe. These results suggest that DVDMS is a promising sensitizer that warrants further development for use in cancer treatment with PDT or other sensitizing agent-based therapies.
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Affiliation(s)
- Xiaobing Wang
- 1. Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China
| | - Jianmin Hu
- 1. Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China
| | - Pan Wang
- 1. Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China
| | - Shaoliang Zhang
- 2. Qinglong High-Tech Co., Ltd, Yichun, Jiangxi, People's Republic of China
| | - Yichen Liu
- 1. Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China
| | - Wenli Xiong
- 1. Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China
| | - Quanhong Liu
- 1. Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China
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9
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Feng X, Zhang Y, Wang P, Liu Q, Wang X. Energy metabolism targeted drugs synergize with photodynamic therapy to potentiate breast cancer cell death. Photochem Photobiol Sci 2014; 13:1793-803. [PMID: 25363473 DOI: 10.1039/c4pp00288a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Malignant cells are highly dependent on aerobic glycolysis, which differs significantly from normal cells (the Warburg effect). Interference of this metabolic process has been considered as an innovative method for developing selective cancer therapy. A recent study demonstrated that the glycolysis inhibitor 2-deoxyglucose (2-DG) can potentiate PDT efficacy, whereas the possible mechanisms have not been carefully investigated. This study firstly proved the general potentiation of PDT efficacy by 2-DG and 3-bromopyruvate (3-BP) in human breast cancer MDA-MB-231 cells, and carefully elucidated the underlying mechanism in the process. Our results showed that both 2-DG and 3-BP could significantly promote a PDT-induced cell cytotoxic effect when compared with either monotherapy. Synergistic potentiation of mitochondria- and caspase-dependent cell apoptosis was observed, including a mitochondrial membrane potential (MMP) drop, Bax translocation, and caspase-3 activation. Besides, ROS generation and the expression of oxidative stress related proteins such as P38 MAPK phosphorylation and JNK phosphorylation were notably increased after the combined treatments. Moreover, when pretreated with the ROS scavenger N-acetylcysteine (NAC), the ROS generation, the MMP drop, cell apoptosis and cytotoxicity were differently inhibited, suggesting that ROS was vertical in the pro-apoptotic process induced by 2-DG/3-BP combined with PDT treatment. These results indicate that the combination of glycolytic antagonists and PDT may be a promising therapeutic strategy to effectively kill cancer cells.
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Affiliation(s)
- Xiaolan Feng
- Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, Ministry of Education, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, China.
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10
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Hu J, Wang X, Liu Q, Zhang K, Xiong W, Xu C, Wang P, Leung AW. Antitumor Effect of Sinoporphyrin Sodium-Mediated Photodynamic Therapy on Human Esophageal Cancer Eca-109 Cells. Photochem Photobiol 2014; 90:1404-12. [DOI: 10.1111/php.12333] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 08/13/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Jianmin Hu
- Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry; Ministry of Education; National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China; College of Life Sciences; Shaanxi Normal University; Xi'an Shaanxi China
| | - Xiaobing Wang
- Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry; Ministry of Education; National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China; College of Life Sciences; Shaanxi Normal University; Xi'an Shaanxi China
| | - Quanhong Liu
- Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry; Ministry of Education; National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China; College of Life Sciences; Shaanxi Normal University; Xi'an Shaanxi China
| | - Kun Zhang
- Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry; Ministry of Education; National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China; College of Life Sciences; Shaanxi Normal University; Xi'an Shaanxi China
| | - Wenli Xiong
- Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry; Ministry of Education; National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China; College of Life Sciences; Shaanxi Normal University; Xi'an Shaanxi China
| | - Chuanshan Xu
- School of Chinese Medicine; Faculty of Medicine; The Chinese University of Hong Kong; Shatin Hong Kong China
| | - Pan Wang
- Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry; Ministry of Education; National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China; College of Life Sciences; Shaanxi Normal University; Xi'an Shaanxi China
- School of Chinese Medicine; Faculty of Medicine; The Chinese University of Hong Kong; Shatin Hong Kong China
| | - Albert Wingnang Leung
- School of Chinese Medicine; Faculty of Medicine; The Chinese University of Hong Kong; Shatin Hong Kong China
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11
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Kessel D, Reiners JJ. Enhanced efficacy of photodynamic therapy via a sequential targeting protocol. Photochem Photobiol 2014; 90:889-95. [PMID: 24617972 DOI: 10.1111/php.12270] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 03/06/2014] [Indexed: 02/06/2023]
Abstract
This study was designed to examine determinants of the discovery that low-dose lysosomal photodamage (lyso-PDT) could potentiate the efficacy of subsequent low-dose mitochondrial photodamage (mito-PDT). The chlorin NPe6 and the benzoporphyrin derivative (BPD) were used to separately target lysosomes and mitochondria, respectively, in murine hepatoma cells. Lyso-PDT (LD(5) conditions) followed by mito-PDT (LD(15) conditions) enhanced the loss of the mitochondrial membrane potential, activation of procaspases-3/7 and photokilling. Reversing the sequence was less effective. The optimal sequence did not enhance reactive oxygen species formation above that obtained with low-dose mito-PDT. In contrast, alkalinization of lysosomes with bafilomycin also enhanced low-dose mito-PDT photokilling, but via a different pathway. This involves redistribution of iron from lysosomes to mitochondria leading to enhanced hydroxyl radical formation, effects not observed after the sequential procedure. Moreover, Ru360, an inhibitor of mitochondrial calcium and iron uptake, partially suppressed the ability of bafilomycin to enhance mito-PDT photokilling without affecting the enhanced efficacy of the sequential protocol. We conclude that sequential PDT protocol promotes PDT efficacy by a process not involving iron translocation, but via promotion of the pro-apoptotic signal that derives from mitochondrial photodamage.
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Affiliation(s)
- David Kessel
- Department of Pharmacology, Wayne State University, Detroit, MI
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13
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Geer MF, Walla MD, Solntsev KM, Strassert CA, Shimizu LS. Self-assembled benzophenone bis-urea macrocycles facilitate selective oxidations by singlet oxygen. J Org Chem 2013; 78:5568-78. [PMID: 23672574 DOI: 10.1021/jo400685u] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This manuscript investigates how incorporation of benzophenone, a well-known triplet sensitizer, within a bis-urea macrocycle, which self-assembles into a columnar host, influences its photophysical properties and affects the reactivity of bound guest molecules. We further report the generation of a remarkably stable organic radical. As expected, UV irradiation of the host suspended in oxygenated solvents efficiently generates singlet oxygen similar to the parent benzophenone. In addition, this host can bind guests such as 2-methyl-2-butene and cumene to form stable solid host-guest complexes. Subsequent UV irradiation of these complexes facilitated the selective oxidation of 2-methyl-2-butene into the allylic alcohol, 3-methyl-2-buten-1-ol, at 90% selectivity as well as the selective reaction of cumene to the tertiary alcohol, α,α'-dimethyl benzyl alcohol, at 63% selectivity. However, these products usually arise through radical pathways and are not observed in the presence of benzophenone in solution. In contrast, typical reactions with benzophenone result in the formation of the reactive singlet oxygen that reacts with alkenes to form endoperoxides, diooxetanes, or hydroperoxides, which are not observed in our system. Our results suggest that the confinement, the formation of a stable radical species, and the singlet oxygen photoproduction are responsible for the selective oxidation processes. A greater understanding of the mechanism of this selective oxidation could lead to development of greener oxidants.
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Affiliation(s)
- Michael F Geer
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
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