Blue light generates reactive oxygen species (ROS) differentially in tumor vs. normal epithelial cells

Lockwood, Daniel B.; Wataha, John C.; Lewis, Jill B.; Tseng, Wan-Yu; Messer, Regina L. W.; Hsu, Stephen

doi:10.1016/j.dental.2004.07.022

Cited by 48 publications

(53 citation statements)

References 22 publications

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“…14 Animal and human studies also have demonstrated the potential utility of blue light for cancer therapy. 15,16 The mechanisms by which blue light affects cells remain unclear, but roles for cellular 14,27,28 These data support a hypothesis that blue light induced-ROS mediate, at least in part, the suppression of mitochondrial function. However, the roles of intra-and extracellular sources of the ROS in causing blue light effects, a possible role for riboflavin or flavins in vitro in generating ROS, and the degree to which these two sources interact to cause cellular responses are unclear.…”

Section: Introductionsupporting

confidence: 70%

“…Collectively, the data support our hypothesis that intra-and extracellularly generated ROS synergize to affect cellular mitochondrial suppression of tumor cells in response to blue light. However, the identity of blue light targets that mediate these changes remain unclear.These data support additional investigations into the risks of coincident exposure of tissues to blue light during material polymerization of restorative materials, and possible therapeutic 14,27,28 These data support a hypothesis that blue light induced-ROS mediate, at least in part, the suppression of mitochondrial function. However, the roles of intra-and extracellular sources of the ROS in causing blue light effects, a possible role for riboflavin or flavins in vitro in generating ROS, and the degree to which these two sources interact to cause cellular responses are unclear.…”

supporting

confidence: 71%

“…The distance from the light tip to the cell monolayer was 9 mm, with 6 mm occupied by the Hallam's. Attenuation of light energy at the level of the monolayer was about 10% (measured in pilot studies and previously reported 27 ). Attenuation was neutral to wavelength in the 380-500 nm range.…”

Section: Light Source and Exposure Conditionsmentioning

confidence: 94%

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Intra‐ and extracellular reactive oxygen species generated by blue light

Omata

Lewis

Rotenberg

et al. 2006

J Biomedical Materials Res

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Acknowledgement of Financial AssistanceThe authors thank the Medical College of Georgia and Ministry of Funding in Japan for seed funds to do this work. 2 SYNOPSISBlue light from dental photopolymerization devices has significant biological effects on cells.These effects may alter normal cell function of tissues exposed during placement of oral restorations, but, recent data suggest that some light-induced effects also may be therapeutically useful, for example in the treatment of epithelial cancers. Reactive oxygen species (ROS) appear to mediate blue light effects in cells, but the sources of ROS (intra-vs. extra-cellular) and their respective roles in the cellular response to blue light are not known. In the current study, we tested the hypothesis that intra-and extra-cellular sources of blue lightgenerated ROS synergize to depress mitochondrial function. Methods: Normal human epidermal keratinocytes (NHEK) and oral squamous cell carcinoma (OSC2) cells were exposed to blue light (380-500 nm; 5-60 J/cm 2 ) from a dental photopolymerization source (quartztungsten-halogen, 550 mW/cm 2 ). Light was applied in cell-culture media or balanced salt solutions with or without cells present. Intracellular ROS levels were estimated using the dihydrofluorescein diacetate (DFDA) assay; extracellular ROS levels were estimated using the leucocrystal violet assay. Cell response was estimated using the MTT mitochondrial activity assay. Results: Blue light increased intracellular ROS equally in both NHEK and OSC2. Blue light also increased ROS levels in cell-free MEM or salt solutions, and riboflavin supplements increased ROS formation. Extracellularly applied ROS rapidly (50-400 μM, < 1 min) increased intracellular ROS levels, which were higher and longer-lived in NHEK than OSC2. The type of cell-culture medium significantly affected the ability of blue light to suppress cellular mitochondrial activity; the greatest suppression was observed in DMEM-containing or NHEK media. Collectively, the data support our hypothesis that intra-and extracellularly generated ROS synergize to affect cellular mitochondrial suppression of tumor cells in response to blue light. However, the identity of blue light targets that mediate these changes remain unclear.These data support additional investigations into the risks of coincident exposure of tissues to blue light during material polymerization of restorative materials, and possible therapeutic 14,27,28 These data support a hypothesis that blue light induced-ROS mediate, at least in part, the suppression of mitochondrial function. However, the roles of intra-and extracellular sources of the ROS in causing blue light effects, a possible role for riboflavin or flavins in vitro in generating ROS, and the degree to which these two sources interact to cause cellular responses are unclear. In the current study, we show that both intra-and extra-cellular ROS are generated by blue light in epithelial cultures, and that both mediate blue light induced-mitochondrial responses. Our data support furthe...

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Section: Introductionsupporting

confidence: 70%

supporting

confidence: 71%

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Intra‐ and extracellular reactive oxygen species generated by blue light

Omata

Lewis

Rotenberg

et al. 2006

J Biomedical Materials Res

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“…The energy densities (EDs) selected for this study were 0.5, 2, 4, 10, and 15 J/cm 2 , according to previous researches conducted in different types of cells [6,11,12,[18][19][20][21][22][23][24]. Since the time of irradiation varied according to the ED, due to the fact that the irradiance was fixed, a corresponding control group was delineated for each ED (Table 1), in which the cells were kept out of the incubator for the same period of time than the corresponding irradiated group.…”

Section: Methodsmentioning

confidence: 99%

“…However, little is known about the effects of the blue light on pulp cells [11,12]. Blue light is routinely used in restorative procedures for the photoactivation of resin-based materials, such as restorative resins, resin cements, adhesive systems, and resinmodified glass ionomer cements.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of dental matrix proteins and viability of odontoblast-like cells irradiated with blue LED

et al. 2016

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To evaluate the effect of irradiation with light-emitting diode (LED; 455 nm) on the viability and synthesis of dentin matrix proteins by odontoblast-like cells, MDPC-23 cells were cultivated (10(4) cells/cm(2)) in 24-well culture plates. After 12 h incubation in Dulbecco's modified Eagle's medium (DMEM), the cells were submitted to nutritional restriction by means of reducing the concentration of fetal bovine serum (FBS) for an additional 12 h. Cells were irradiated one single time with one of the following energy densities (EDs): 0.5, 2, 4, 10, or 15 J/cm(2) and irradiance fixed at 20 mW/cm(2). Non-irradiated cells served as control. After 72 h, cells were evaluated with regard to viability (methylthiazol tetrazolium technique (MTT)), mineralization nodule (MN) formation, total protein (TP) production, alkaline phosphatase activity (ALP), and collagen synthesis (Sircol), n = 8. The data were submitted to Kruskal-Wallis and Mann-Whitney tests (p > 0.05). There was no statistical difference between the viability of cells irradiated or not (control), for all the EDs. However, an increase in TP was observed for all the EDs when compared with the control group. A reduced ALP activity was seen in all irradiated groups, except for the ED of 0.5 J/cm(2), which did not differ from the control. There was no difference between the irradiated groups and control regarding collagen synthesis, with the exception of the ED of 10 J/cm(2), which inhibited this cell function. Significant reduction in MN occurred only for the EDs of 0.5 and 2 J/cm(2). The single irradiation with blue LED (455 nm), irradiance of 20 mW/cm(2), and energy densities ranging from 0.5 to 15 J/cm(2) exerted no effective biostimulatory capacity on odontoblast-like cells.

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Effect of blue light‐emitting diode light and antioxidant potential in a somatic cell

Bapary

Takano

Soma

et al. 2019

Cell Biology International

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Light is an indispensable part of routine laboratory work in which conventional light is generally used. Light-emitting diodes (LEDs) have come to replace conventional light, and thus could be a potent target in biomedical studies. Since blue light is a major component of visible light wavelength, in this study, using a somatic cell from the African green monkey kidney, we assessed the possible consequences of the blue spectra of LED light in future animal experiments and proposed a potent mitigation against light-induced damage. COS-7 cells were exposed to blue LED light (450 nm) and the growth and deoxyribonucleic acid (DNA) damage were assessed at different exposure times. A higher suppression in cell growth and viability was observed under a longer period of blue LED light exposure. The number of apoptotic cells increased as the light exposure time was prolonged. Reactive oxygen species (ROS) generation was also elevated in accordance to the extension of light exposure time. A comparison with dark-maintained cells revealed that the upregulation of ROS by blue LED light plays a significant role in causing cellular dysfunction in DNA in a time-dependent manner. In turn, antioxidant treatment has been shown to improve cell growth and viability under blue LED light conditions. This indicates that antioxidants have potential against blue LED light-induced somatic cell damage. It is expected that this study will contribute to the understanding of the basic mechanism of somatic cell death under visible light and maximize the beneficial use of LED light in future animal experiments.

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Blue light generates reactive oxygen species (ROS) differentially in tumor vs. normal epithelial cells

Cited by 48 publications

References 22 publications

Intra‐ and extracellular reactive oxygen species generated by blue light

Intra‐ and extracellular reactive oxygen species generated by blue light

Synthesis of dental matrix proteins and viability of odontoblast-like cells irradiated with blue LED

Effect of blue light‐emitting diode light and antioxidant potential in a somatic cell

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