The term "metronomic" was recently introduced to describe continuous low-dose administration of chemotherapeutics following the discovery that this causes minimal side effects (Hanahan et al. 2000, J Clin Invest, 105(8), 1045-1047; Bisland et al. 2004, Photochem Photobiol, 80, 22-30). Metronomic dosing in PDT is proposed by analogy and the rationale is as a means to improve the tumor-specific response through cell death by apoptosis. We investigated the molecular mechanisms associated with apoptosis following ALA-PDT treatment in two brain glioma cell lines, namely U87 (human) and CNS-1 (rat) cells. We used the high energy of light at a short time (acute PDT) and the low energy of light at a long time of exposure (metronomic PDT) to treat both cell lines. To identify potential cell death pathways associated with metronomic PDT, microarray analysis of gene expression was conducted on RNA from glioblastoma cells with metronomic ALA-PDT. The apoptosis mechanism for metronomic ALA-PDT occurred via the inhibition of LTbetaR and the transcription factor NF-kappaB. This inhibition was ALA concentration dependent.
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http://dx.doi.org/10.1007/978-1-60761-697-9_5 | DOI Listing |
Angew Chem Int Ed Engl
November 2024
Department of Environmental and Chemical Engineering, Shanghai University, Nanchen Rd. 333, Shanghai, China.
Photodynamic therapy (PDT) has been used clinically to treat superficial tumors for decades. However, its effectiveness against deep-seated tumors has been limited by the inefficient delivery of the key components -light, photosensitizer, and oxygen- required for the photochemical reactions in PDT. Here, we present a novel platform that enables the photochemical reaction to occur in a self-driven manner, eliminating the need for external delivery of these components and instead orchestrating their endogenous generation within tumors.
View Article and Find Full Text PDFCells
June 2023
Departamento de Biología Molecular, Facultad de Ciencias Exactas, Fisicoquímicas y Naturales, UNRC, Río Cuarto X5800BIA, Argentina.
Alternative therapies such as photodynamic therapy (PDT) that combine light, oxygen and photosensitizers (PSs) have been proposed for glioblastoma (GBM) management to overcome conventional treatment issues. An important disadvantage of PDT using a high light irradiance (fluence rate) (cPDT) is the abrupt oxygen consumption that leads to resistance to the treatment. PDT metronomic regimens (mPDT) involving administering light at a low irradiation intensity over a relatively long period of time could be an alternative to circumvent the limitations of conventional PDT protocols.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2023
Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430034, China.
Metronomic photodynamic therapy (mPDT), which induces cancer cell death by prolonged intermittent continuous irradiation at lower light power, has profoundly promising applications. However, the photobleaching sensitivity of the photosensitizer (PS) and the difficulty of delivery pose barriers to the clinical application of mPDT. Here, we constructed a microneedle-based device (Microneedles@AIE PSs) that combined with aggregation-induced emission (AIE) PSs to achieve enhanced mPDT for cancer.
View Article and Find Full Text PDFACS Omega
December 2022
School of Public Health, Jilin University, Changchun, 130021 Jilin, China.
Photodynamic therapy (PDT) is an effective treatment modality for various cancer types. However, tumor recurrence and metastasis stemming from residual cancer cells after PDT pose serious problems. In this study, a simple multifunctional PTX@Ce6 nanomedicine is prepared using a two-step reprecipitation method.
View Article and Find Full Text PDFSci Rep
December 2020
Department of Physiology, National Defense Medical College, Namiki 3-2, Tokorozawa, Saitama, 359-8513, Japan.
Metronomic photodynamic therapy (mPDT) is a form of PDT that induces cancer cell death by intermittent continuous irradiation with a relatively weak power of light for a long duration (several days). We previously developed a wirelessly powered, fully implantable LED device and reported a significant anti-tumor effect of mPDT. Considering application in clinical practice, the method used for repeated administrations of photosensitizers required for mPDT should not have a high patient burden such as the burden of transvenous administration.
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