Tumor response to mTHPC-mediated photodynamic therapy exhibits strong correlation with extracellular release of HSP70.

Background And Objective: We investigated the relationship among heat shock protein 70 (hsp70) promoter activation, extracellular HSP70 protein levels, and tumor cure in an animal model of meso-tetrahydroxyphenyl chlorin (mTHPC; Foscan®)-mediated photodynamic therapy (PDT).

Materials And Methods: Using Western blot analysis, we compared HSP70 protein levels in control and PDT-treated EMT6 cells with the amplitude of hsp70-promoter driven green fluorescent protein (GFP) expression in identically treated, stably transfected hsp70-GFP/EMT6 cells. A clonogenic survival assay was performed to assess the relationship among promoter activation, HSP70 levels, and cell survival in vitro.

Effective photosensitization and selectivity in vivo of Candida Albicans by meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate.

Background And Objective: The fungus Candida albicans commonly causes mucosal and cutaneous infections in patients with impaired immunity. We investigated the effectiveness of the photosensitizer meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP-1363) in the photodynamic treatment (PDT) of C. albicans infection in vitro and its selectivity in an animal model.

Factors influencing tumor response to photodynamic therapy sensitized by intratumor administration of methylene blue.

Background And Objectives: We examined tumor response to methylene blue (MB)-mediated photodynamic therapy (PDT) in a murine tumor model. The goal was to investigate the effects of drug-light interval (DLI), injection vehicle, and fluence on tumor destruction. Fluorescence and reflectance spectroscopy informed our understanding.

Inhibition of electron transport chain assembly and function promotes photodynamic killing of Candida.

Respiratory deficiency increases the sensitivity of the pathogenic fungi Candida albicans and Candida glabrata to oxidative stress induced by photodynamic therapy (PDT) sensitized by the cationic porphyrin meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP-1363). Since disruption of electron transport chain (ETC) function increases intracellular levels of reactive oxygen species in yeast, we determined whether interference with ETC assembly or function increased sensitivity to TMP-1363-PDT in C. albicans, C.

Intratumor administration of the photosensitizer pc 4 affords photodynamic therapy efficacy and selectivity at short drug-light intervals.

We evaluated intratumor (IT) versus intravenous (IV) administration of the photosensitizer Pc 4 with respect to tumor photosensitizer concentration, specificity, and responses to irradiation. BALB/c mice bearing intradermal EMT6 tumors were given 0.3 mg/kg Pc 4 injected IT or IV through the tail vein.

Lysosome-damage-induced scattering changes coincide with release of cytochrome c.

Light scattering measurements made at visible wavelengths have the ability to quantify subcellular morphology. Apoptosis, or programmed cell death, is associated with distinct morphological signatures such as mitochondrial swelling and nuclear condensation as well as characteristic biochemical signaling pathways, many of which are initiated by the release of cytochrome c from the mitochondria into the cytosol. In this Letter, we examine the time course of mitochondrial morphology changes as reported by light scattering and the subcellular location of cytochrome c measured by immunofluorescence microscopy in response to intracellular cell death signaling induced by photodynamic damage to lysosomes.