Topic
Protoporphyrin IX
About: Protoporphyrin IX is a research topic. Over the lifetime, 2250 publications have been published within this topic receiving 65544 citations. The topic is also known as: PpIX.
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TL;DR: The procedure was developed as a simple means of detecting increased levels of “free” protoporphyrin in capillary blood samples from young children with iron deficiency or increased lead absorption or both, and gives reproducible results in the hands of persons without prior formal training in laboratory skills.
19 citations
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TL;DR: Results indicated that PPIX-mediated sonodynamic effect could exert its antitumor effect by triggering apoptosis in S180 cells through a Fas-mediated signal transduction pathway.
Abstract: This study was to investigate whether the apoptosis in isolate sarcoma 180 (S180) cells could be enhanced by ultrasound in the presence of protoporphyrin IX (PPIX) and also to evaluate the underlying biologic mechanism. S180 cells were exposed to ultrasound for 30 seconds' duration, at the frequency of 2.2 MHz and an acoustical power of 3 W/cm2 with 120 μM of PPIX. Cell apoptosis was evaluated based on the morphologic changes at different incubation times after sonication. Our results showed that the apoptosis in S180 tumor cells were induced by exposure, and the rate of apoptosis rose gradually with a longer incubation time. Our results also showed that changes in Fas protein expression were correlated with the development of apoptosis. The activities of caspase-8 and -3 were apparently upregulated by apoptosis, and the death substrate (PARP) was cleaved to active segments in a time-dependent manner. These results indicated that PPIX-mediated sonodynamic effect could exert its antitumor effect by trigger...
19 citations
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TL;DR: Investigation of the modulation and pharmacokinetics of PPIX buildup after a 5 h incubation with ALA and one of its derivatives, the hexyl ester of ALA, on the human epidermal equivalent Epidex™ found a modified fluorescence spectrum, with the emergence of a peak at 590 nm, which is attributed to zinc protoporphyrin IX (Zn PPIX).
Abstract: Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) or its derivatives as precursors of protoporphyrin IX (PPIX) is routinely used in dermatology for the treatment of various pathologies. However, this methodology suffers to some extent from a limited efficacy. Therefore, the main goal of this study was to investigate the modulation and pharmacokinetics of PPIX buildup after a 5 h incubation with ALA (1.5 mM) and one of its derivatives, the hexyl ester of ALA (h-ALA) (1.5 mM), on the human epidermal equivalent Epidex. PPIX production was modulated with (L+) ascorbic acid iron (II) salt (LAI) or the iron (II)-specific chelating agent deferoxamine (DFO). PPIX fluorescence from the Epidex layers was measured up to 150 h after the precursor administration using a microspectrofluorometer (lambda(ex): 400 +/- 20 nm; lambda(det): 635 nm). The maximum PPIX fluorescence intensity induced by h-ALA was about 1.7 x larger than that induced by ALA. The addition of DFO resulted in a more than 50% increase in PPIX fluorescence for both precursors. The decay half life measured for PPIX fluorescence is 30 and 42.5 h, respectively, for ALA and h-ALA. These half lives are doubled when the samples contain DFO. In the samples with the highest fluorescence intensity, a modified fluorescence spectrum was observed after 10 h, with the emergence of a peak at 590 nm, which is attributed to zinc protoporphyrin IX (Zn PPIX).
19 citations
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18 citations
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TL;DR: It is demonstrated that transfection of NeuT (a mutated Her2/Neu) oncogene in MCF10A human breast epithelial cells significantly enhanced ALA-induced PpIX fluorescence by elevating some enzymes involved in Ppix biosynthesis, and this results support the use of ALA for imaging and photodynamic targeting Her2 /Neu-positive tumors.
Abstract: // Xue Yang 1 , Pratheeba Palasuberniam 1 , Kenneth A. Myers 2 , Chenguang Wang 3 , Bin Chen 1 1 Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, University of The Sciences, Philadelphia, Pennsylvania, USA 2 Department of Biological Sciences, Misher College of Arts and Sciences, University of The Sciences, Philadelphia, Pennsylvania, USA 3 Key Laboratory of Tianjin Radiation and Molecular Nuclear Medicine, Institute of Radiation Medicine, Peking Union Medical College and Chinese Academy of Medical Sciences, Tianjin, China Correspondence to: Bin Chen, email: b.chen@usciences.edu Keywords: human epidermal growth receptor 2 (Her2), aminolevulinic acid (ALA), protoporphyrin IX (PpIX), photodynamic therapy (PDT), heme biosynthesis Received: April 04, 2016 Accepted: July 19, 2016 Published: August 04, 2016 ABSTRACT Enhanced protoporphyrin IX (PpIX) production in tumors derived from the administration of 5-aminolevulinic acid (ALA) enables the use of ALA as a prodrug for photodynamic therapy (PDT) and fluorescence-guided tumor resection. Although ALA has been successfully used in the clinic, the mechanism underlying enhanced ALA-induced PpIX production in tumors is not well understood. Human epidermal growth receptor 2 (Her2, Neu, ErbB2) is a driver oncogene in human cancers, particularly breast cancers. Here we showed that, in addition to activating Her2/Neu cell signaling, inducing epithelial-mesenchymal transition and upregulating glycolytic enzymes, transfection of NeuT (a mutated Her2/Neu) oncogene in MCF10A human breast epithelial cells significantly enhanced ALA-induced PpIX fluorescence by elevating some enzymes involved in PpIX biosynthesis. Furthermore, NeuT-transformed and vector control cells exhibited drastic differences in the intracellular localization of PpIX, either produced endogenously from ALA or applied exogenously. In vector control cells, PpIX displayed a cell contact-dependent membrane localization at high cell densities and increased mitochondrial localization at low cell densities. In contrast, no predominant membrane localization of PpIX was observed in NeuT cells and ALA-induced PpIX showed a consistent mitochondrial localization regardless of cell density. PDT with ALA caused significantly more decrease in cell viability in NeuT cells than in vector cells. Our data demonstrate that NeuT oncogene transformation enhanced ALA-induced PpIX production and altered PpIX intracellular localization, rendering NeuT-transformed cells increased response to ALA-mediated PDT. These results support the use of ALA for imaging and photodynamic targeting Her2/Neu-positive tumors.
18 citations