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Selenocysteine derivative overcomes TRAIL resistance in melanoma cells: evidence for ROS-dependent synergism and signaling crosstalk.

Cao W, Li X, Zheng S, Zheng W, Wong YS, Chen T - Oncotarget (2014)

Bottom Line: Moreover, silencing of p53 down-regulated the expression levels of p53-inducible genes, and effectively blocked the cell apoptosis.Suppression of PI3K significantly increased the apoptotic cell death.In contrast, antioxidants effectively reversed the cell apoptosis through regulation of Akt and p53 signaling pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Jinan University, Guangzhou, China.

ABSTRACT
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), as one of the most promising targeted drug for new cancer therapeutics, is limited in clinical application by the evolution of resistance in many cancer cell lines, especially in malignant melanoma. Thus, it is urgently needed to identify chemosensitizers to enhance the apoptotic inducing efficacy of TRAIL and overcome resistance of malignant melanoma cells. Herein, we reported that 3,3'-diselenodipropionic acid (DSeA), a Selenocysteine derivative, could synergistically enhance the growth inhibitory effect of TRAIL on A375 melanoma cells though induction of ROS-dependent apoptosis with involvement of PTEN-mediated Akt inactivation and DNA damage-mediated p53 phosphorylation, which subsequently activated mitochondrial and death receptor apoptotic pathways. Moreover, silencing of p53 down-regulated the expression levels of p53-inducible genes, and effectively blocked the cell apoptosis. Suppression of PI3K significantly increased the apoptotic cell death. In contrast, antioxidants effectively reversed the cell apoptosis through regulation of Akt and p53 signaling pathways. Taken together, the combination of DSeA and TRAIL could be a novel strategy to overcome TRAIL resistance in malignant melanoma, and DSeA may be candidates for further evaluation as a chemosensitizer in clinical trails.

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Related in: MedlinePlus

DSeA and TRAIL synergistically inhibit growth of A375 cellsCell viability was determined by MTT assay as described in Methods. (A) The chemical structure of DSeA. (B) DSeA enhances the efficacy of TRAIL-induced A375 cells growth inhibition. Cells were pretreated with or without 20 μM DSeA for 0, 6, 12 or 24 h and then incubated in the presence or absence of 40 ng/ml TRAIL for another 24 h. (C) Cells were pretreated with or without indicated concentrations of DSeA for 24 h and then co-treated with 40 ng/ml TRAIL for 24 h. (D) Cytotoxic effects of co-treatment on human normal cell lines HK-2 and L02. Cells were pretreated with 20 μM DSeA for 24 h and then expose to 40 ng/ml TRAIL for another 24 h. (E) Isobologram analysis of the synergistic antiproliferative effect of co-treatment on A375 cell. The data points (A, B) in the isobologram correspond to the actual IC50 value of DSeA and TRAIL with different ratio of concentrations in the combined treatment. DSeA (μM): TRAIL (ng/ml) = 1:4, 1:2. (F) The CI corresponding to different ratio of concentrations in the combined treatment. Each value represents the mean ± SD of three independent experiments. Bars with different characters (a, b, c, d and e) are statistically different at p < 0.05 level.
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Figure 1: DSeA and TRAIL synergistically inhibit growth of A375 cellsCell viability was determined by MTT assay as described in Methods. (A) The chemical structure of DSeA. (B) DSeA enhances the efficacy of TRAIL-induced A375 cells growth inhibition. Cells were pretreated with or without 20 μM DSeA for 0, 6, 12 or 24 h and then incubated in the presence or absence of 40 ng/ml TRAIL for another 24 h. (C) Cells were pretreated with or without indicated concentrations of DSeA for 24 h and then co-treated with 40 ng/ml TRAIL for 24 h. (D) Cytotoxic effects of co-treatment on human normal cell lines HK-2 and L02. Cells were pretreated with 20 μM DSeA for 24 h and then expose to 40 ng/ml TRAIL for another 24 h. (E) Isobologram analysis of the synergistic antiproliferative effect of co-treatment on A375 cell. The data points (A, B) in the isobologram correspond to the actual IC50 value of DSeA and TRAIL with different ratio of concentrations in the combined treatment. DSeA (μM): TRAIL (ng/ml) = 1:4, 1:2. (F) The CI corresponding to different ratio of concentrations in the combined treatment. Each value represents the mean ± SD of three independent experiments. Bars with different characters (a, b, c, d and e) are statistically different at p < 0.05 level.

Mentions: In the present study, human melanoma A375 cells, a TRAIL-resistance cell line was chose to evaluate the antiproliferative effects of combined DSeA (Fig. 1A) and TRAIL treatment by MTT assay. Firstly, the treatment of A375 cells with 10-320 μM DSeA for 6, 12, 24, 36 and 48 h or 10-1280 ng/ml TRAIL for 24 h inhibited cell proliferation in a time- and dose-dependent manner. In order to establish an optimal strategy in the combined treatment, cells were pretreated with different concentrations of DSeA for 0, 6, 12 and 24 h, and then co-treated with different concentrations of TRAIL for additional 24 h. As shown in Fig. 1B and Fig. 1C, pretreatment of cells with 20, 40 μM DSeA for 24 h and then co-treatment with 40 ng/ml TRAIL for 24 h significantly inhibits cell proliferation at 45.3% and 14.0%, respectively, indicating that the DSeA pretreatment notably enhances the growth inhibitory efficacy of TRAIL in a time- and dose-dependent manner. Despite the notable antiproliferative effects, the combined treatment with DSeA and TRAIL exhibited lower cytotoxicity towards human normal cell lines HK-2 and L02 (Fig. 1D).


Selenocysteine derivative overcomes TRAIL resistance in melanoma cells: evidence for ROS-dependent synergism and signaling crosstalk.

Cao W, Li X, Zheng S, Zheng W, Wong YS, Chen T - Oncotarget (2014)

DSeA and TRAIL synergistically inhibit growth of A375 cellsCell viability was determined by MTT assay as described in Methods. (A) The chemical structure of DSeA. (B) DSeA enhances the efficacy of TRAIL-induced A375 cells growth inhibition. Cells were pretreated with or without 20 μM DSeA for 0, 6, 12 or 24 h and then incubated in the presence or absence of 40 ng/ml TRAIL for another 24 h. (C) Cells were pretreated with or without indicated concentrations of DSeA for 24 h and then co-treated with 40 ng/ml TRAIL for 24 h. (D) Cytotoxic effects of co-treatment on human normal cell lines HK-2 and L02. Cells were pretreated with 20 μM DSeA for 24 h and then expose to 40 ng/ml TRAIL for another 24 h. (E) Isobologram analysis of the synergistic antiproliferative effect of co-treatment on A375 cell. The data points (A, B) in the isobologram correspond to the actual IC50 value of DSeA and TRAIL with different ratio of concentrations in the combined treatment. DSeA (μM): TRAIL (ng/ml) = 1:4, 1:2. (F) The CI corresponding to different ratio of concentrations in the combined treatment. Each value represents the mean ± SD of three independent experiments. Bars with different characters (a, b, c, d and e) are statistically different at p < 0.05 level.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4202134&req=5

Figure 1: DSeA and TRAIL synergistically inhibit growth of A375 cellsCell viability was determined by MTT assay as described in Methods. (A) The chemical structure of DSeA. (B) DSeA enhances the efficacy of TRAIL-induced A375 cells growth inhibition. Cells were pretreated with or without 20 μM DSeA for 0, 6, 12 or 24 h and then incubated in the presence or absence of 40 ng/ml TRAIL for another 24 h. (C) Cells were pretreated with or without indicated concentrations of DSeA for 24 h and then co-treated with 40 ng/ml TRAIL for 24 h. (D) Cytotoxic effects of co-treatment on human normal cell lines HK-2 and L02. Cells were pretreated with 20 μM DSeA for 24 h and then expose to 40 ng/ml TRAIL for another 24 h. (E) Isobologram analysis of the synergistic antiproliferative effect of co-treatment on A375 cell. The data points (A, B) in the isobologram correspond to the actual IC50 value of DSeA and TRAIL with different ratio of concentrations in the combined treatment. DSeA (μM): TRAIL (ng/ml) = 1:4, 1:2. (F) The CI corresponding to different ratio of concentrations in the combined treatment. Each value represents the mean ± SD of three independent experiments. Bars with different characters (a, b, c, d and e) are statistically different at p < 0.05 level.
Mentions: In the present study, human melanoma A375 cells, a TRAIL-resistance cell line was chose to evaluate the antiproliferative effects of combined DSeA (Fig. 1A) and TRAIL treatment by MTT assay. Firstly, the treatment of A375 cells with 10-320 μM DSeA for 6, 12, 24, 36 and 48 h or 10-1280 ng/ml TRAIL for 24 h inhibited cell proliferation in a time- and dose-dependent manner. In order to establish an optimal strategy in the combined treatment, cells were pretreated with different concentrations of DSeA for 0, 6, 12 and 24 h, and then co-treated with different concentrations of TRAIL for additional 24 h. As shown in Fig. 1B and Fig. 1C, pretreatment of cells with 20, 40 μM DSeA for 24 h and then co-treatment with 40 ng/ml TRAIL for 24 h significantly inhibits cell proliferation at 45.3% and 14.0%, respectively, indicating that the DSeA pretreatment notably enhances the growth inhibitory efficacy of TRAIL in a time- and dose-dependent manner. Despite the notable antiproliferative effects, the combined treatment with DSeA and TRAIL exhibited lower cytotoxicity towards human normal cell lines HK-2 and L02 (Fig. 1D).

Bottom Line: Moreover, silencing of p53 down-regulated the expression levels of p53-inducible genes, and effectively blocked the cell apoptosis.Suppression of PI3K significantly increased the apoptotic cell death.In contrast, antioxidants effectively reversed the cell apoptosis through regulation of Akt and p53 signaling pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Jinan University, Guangzhou, China.

ABSTRACT
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), as one of the most promising targeted drug for new cancer therapeutics, is limited in clinical application by the evolution of resistance in many cancer cell lines, especially in malignant melanoma. Thus, it is urgently needed to identify chemosensitizers to enhance the apoptotic inducing efficacy of TRAIL and overcome resistance of malignant melanoma cells. Herein, we reported that 3,3'-diselenodipropionic acid (DSeA), a Selenocysteine derivative, could synergistically enhance the growth inhibitory effect of TRAIL on A375 melanoma cells though induction of ROS-dependent apoptosis with involvement of PTEN-mediated Akt inactivation and DNA damage-mediated p53 phosphorylation, which subsequently activated mitochondrial and death receptor apoptotic pathways. Moreover, silencing of p53 down-regulated the expression levels of p53-inducible genes, and effectively blocked the cell apoptosis. Suppression of PI3K significantly increased the apoptotic cell death. In contrast, antioxidants effectively reversed the cell apoptosis through regulation of Akt and p53 signaling pathways. Taken together, the combination of DSeA and TRAIL could be a novel strategy to overcome TRAIL resistance in malignant melanoma, and DSeA may be candidates for further evaluation as a chemosensitizer in clinical trails.

Show MeSH
Related in: MedlinePlus