Transfection of nonmelanocytic cells with tyrosinase gene constructs for survival studies

Kaur, Jaskiran; Hill, Helene Z.

doi:10.1002/em.1074

Cited by 3 publications

(2 citation statements)

References 47 publications

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“…Reactive oxygen species (ROS), such as O2·-, ·OH, and H 2 O 2 , are the principal species of intracellular oxidants (Leonard et al, 2010). They are generated as by-products of electron transport through the mitochondrial respiratory chain as well as by γ-ray and ultraviolet light irradiations (Kaur et al, 2001). ROS are highly reactive toward intracellular macromolecules (DNA, proteins and lipids), causing severe lesions that can lead to the cell death by either necrosis or apoptosis, depending on the intensity of the oxidative stimuli (He et al, 2012;Ni et al, 2012;Plante et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Bcl-2 Overexpression Inhibits Generation of Intracellular Reactive Oxygen Species and Blocks Adriamycin-induced Apoptosis in Bladder Cancer Cells

Kong¹,

Zhang²

2013

Asian Pacific Journal of Cancer Prevention

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Section: Introductionmentioning

confidence: 99%

Bcl-2 Overexpression Inhibits Generation of Intracellular Reactive Oxygen Species and Blocks Adriamycin-induced Apoptosis in Bladder Cancer Cells

Kong¹,

Zhang²

2013

Asian Pacific Journal of Cancer Prevention

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“…Next, we increased PT contrast of nonmelanoma cells by stimulating melanin synthesis (46). Melanogenesis was induced in MDA-MB-231 breast cancer cells after introduction of a plasmid expressing an eGFP-tagged tyrosinase gene (47). Melanin formation in breast cancer cells was detected just 1 day following plasmid transfection ( Fig.…”

Section: Imaging and Identification Of Intracellular Melaninmentioning

confidence: 99%

Photothermal Confocal Spectromicroscopy of Multiple Cellular Chromophores and Fluorophores

Nedosekin

Galanzha

Ayyadevara

et al. 2012

Biophysical Journal

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Confocal fluorescence microscopy is a powerful biological tool providing high-resolution, three-dimensional (3D) imaging of fluorescent molecules. Many cellular components are weakly fluorescent, however, and thus their imaging requires additional labeling. As an alternative, label-free imaging can be performed by photothermal (PT) microscopy (PTM), based on nonradiative relaxation of absorbed energy into heat. Previously, little progress has been made in PT spectral identification of cellular chromophores at the 3D microscopic scale. Here, we introduce PTM integrating confocal thermal-lens scanning schematic, time-resolved detection, PT spectral identification, and nonlinear nanobubble-induced signal amplification with a tunable pulsed nanosecond laser. The capabilities of this confocal PTM were demonstrated for high-resolution 3D imaging and spectral identification of up to four chromophores and fluorophores in live cells and Caenorhabditis elegans. Examples include cytochrome c, green fluorescent protein, Mito-Tracker Red, Alexa-488, and natural drug-enhanced or genetically engineered melanin as a PT contrast agent. PTM was able to guide spectral burning of strong absorption background, which masked weakly absorbing chromophores (e.g., cytochromes in the melanin background). PTM provided label-free monitoring of stress-related changes to cytochrome c distribution, in C. elegans at the single-cell level. In nonlinear mode ultrasharp PT spectra from cyt c and the lateral resolution of 120 nm during calibration with 10-nm gold film were observed, suggesting a potential of PTM to break through the spectral and diffraction limits, respectively. Confocal PT spectromicroscopy could provide a valuable alternative or supplement to fluorescence microscopy for imaging of nonfluorescent chromophores and certain fluorophores.

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Inhibition of melanogenesis as a radiation sensitizer for melanoma therapy

Brożyna¹,

VanMiddlesworth²,

Slominski³

2008

Intl Journal of Cancer

126

113

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Melanin pigment displays strong photo-and radioprotective properties, suggesting that inhibition melanogenesis could increase sensitivity of melanoma to ionizing radiation. We tested this concept in human melanoma cells cultured in either Ham's F10 medium to maintain amelanotic phenotype or DMEM to induce/stimulate melanin production, respectively; N-phenylthiourea (PTU) and Dpenicillamine were used as an inhibitor of melanogenesis. Melanogenic activity was evaluated by visual inspection (color of cell pellets) or by measurement of tyrosinase (dopa oxidase) activity assay. Amelanotic cells or cells with various melanin content were exposed to gamma radiation and tested for viability and colony forming capability. Gamma radiation at doses of 2-15 Gy inhibited cell viability and colony forming efficiency in dose-and timedependent manner, but pigmented melanoma cells were significantly more resistant to gamma radiation than nonpigmented cells (p < 0.05-0.001). Both PTU and D-penicillamine inhibited strongly tyrosinase activity and melanin production in melanoma cells (p < 0.05-0.001). Furthermore, inhibition of melanogenesis by PTU or D-penicillamine resulted in enhancement of melanoma cells sensitivity to killing by gamma rays. In conclusion, the results of these cell culture experiments give support to a clinical trial of pharmacologically induced decrease in melanin synthesis to enhance the efficacy of radiotherapy in advanced melanomas. ' 2008 Wiley-Liss, Inc.Key words: melanogenesis; melanin; melanoma; tyrosinase; gamma radiation Melanoma is the tumor with the most rapidly increasing incidences worldwide and it is predicted that by 2010, 1 person out of 50 white persons will be affected by this disease.1 Surgical excision is an effective treatment for early-stage melanomas (localized to the skin), and it is widely accepted that melanoma is resistant to all therapeutic modalities once the metastatic process started. 1-4The use of radiotherapy for advanced melanoma is controversial, and it serves mainly as palliative treatment. [5][6][7][8][9] Most likely the radioresistance of melanoma is due to the presence of melanin pigment, which acts as endogenous radioprotector. 10,11The major role of cutaneous melanin is protection against the harmful actions of solar radiation, by acting as a filter against ultraviolet radiation (UVR), preventing its penetration and genotoxicity (formation of UV-induced DNA dimmers).11-16 Melanin also neutralizes reactive oxygen species (ROS) generated mostly by UVA, through its antioxidative and free-radical scavenging actions. 13,16,17 Overall, melanin protects against epidermal carcinogenesis or melanomagenesis. 11,12,14,16 Nevertheless, the same positive capacity of melanin to scavenge free radical and ROS becomes undesirable in the response of melanoma to radio-, photo-or chemotherapy 11,16,[18][19][20] ; furthermore, the pro-oxidant properties of melanin can, in certain conditions, stimulate melanoma progression. 21Melanotic and amelanotic melanomas differ in their sensitivity to...

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Transfection of nonmelanocytic cells with tyrosinase gene constructs for survival studies

Cited by 3 publications

References 47 publications

Bcl-2 Overexpression Inhibits Generation of Intracellular Reactive Oxygen Species and Blocks Adriamycin-induced Apoptosis in Bladder Cancer Cells

Bcl-2 Overexpression Inhibits Generation of Intracellular Reactive Oxygen Species and Blocks Adriamycin-induced Apoptosis in Bladder Cancer Cells

Photothermal Confocal Spectromicroscopy of Multiple Cellular Chromophores and Fluorophores

Inhibition of melanogenesis as a radiation sensitizer for melanoma therapy

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