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Tudor staphylococcal nuclease drives chemoresistance of non-small cell lung carcinoma cells by regulating S100A11.

Zagryazhskaya A, Surova O, Akbar NS, Allavena G, Gyuraszova K, Zborovskaya IB, Tchevkina EM, Zhivotovsky B - Oncotarget (2015)

Bottom Line: Lung cancer is the leading cause of cancer-related deaths worldwide.Silencing of TSN was accompanied by a significant decrease in S100A11 expression at both mRNA and protein level.Moreover, silencing of S100A11 stimulated mitochondrial superoxide production, which was decreased by AACOCF(3), as well as N-acetyl-L-cysteine, which also mimicked the effect of PLA(2) inhibitor on NSCLC chemosensitization upon S100A11 silencing.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environmental Medicine, Division of Toxicology, Stockholm, Sweden.

ABSTRACT
Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC), the major lung cancer subtype, is characterized by high resistance to chemotherapy. Here we demonstrate that Tudor staphylococcal nuclease (SND1 or TSN) is overexpressed in NSCLC cell lines and tissues, and is important for maintaining NSCLC chemoresistance. Downregulation of TSN by RNAi in NSCLC cells led to strong potentiation of cell death in response to cisplatin. Silencing of TSN was accompanied by a significant decrease in S100A11 expression at both mRNA and protein level. Downregulation of S100A11 by RNAi resulted in enhanced sensitivity of NSCLC cells to cisplatin, oxaliplatin and 5-fluouracil. AACOCF(3), a phospholipase A(2) (PLA(2)) inhibitor, strongly abrogated chemosensitization upon silencing of S100A11 suggesting that PLA(2) inhibition by S100A11 governs the chemoresistance of NSCLC. Moreover, silencing of S100A11 stimulated mitochondrial superoxide production, which was decreased by AACOCF(3), as well as N-acetyl-L-cysteine, which also mimicked the effect of PLA(2) inhibitor on NSCLC chemosensitization upon S100A11 silencing. Thus, we present the novel TSN-S100A11-PLA(2) axis regulating superoxide-dependent apoptosis, triggered by platinum-based chemotherapeutic agents in NSCLC that may be targeted by innovative cancer therapies.

No MeSH data available.


Related in: MedlinePlus

Tudor-SN is overexpressed in non-small cell lung cancer cells and patients’ tissues, and its silencing sensitizes NSCLC cells to cisplatinA. The level of TSN protein expression in normal human lung fibroblasts AG06814 and in NSCLC cell lines (A549, H661, U1810 and H23), left panel. Densitometric analysis of the western blotting bands for TSN normalized to β-actin is presented in the right panel. Results shown are the mean ± standard error of the mean of three independent experiments. B. The level of TSN protein expression in 17 pairs of NSCLC tumor (T) tissues and corresponding adjacent normal (N) tissues. Densitometric analysis of the western blotting bands for TSN normalized to β-actin is presented in the lower panel. C. Cleavage of PARP and processing of caspase-9 and -3 in A549 treated as indicated (cispl, 5 μg/ml for 24 hours). GAPDH was used as loading control. D. Caspase-3-like activity (fold change versus control) in A549 cells treated as indicated (cispl, 5 μg/ml for 24 hours). E. Representative DNA histograms displaying genomic DNA fragmentation in A549 cells treated as indicated (cispl, 5 μg/ml for 48 hours). The percentage of cells in sub-G1 fraction is indicated above the marked area in each diagram. F. Colony formation by A549 cells treated as indicated. The results are shown as the mean ± SEM of three independent experiments. P < 0.05. For details see “Materials and Methods” section. All data are representative of three independent experiments.
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Figure 1: Tudor-SN is overexpressed in non-small cell lung cancer cells and patients’ tissues, and its silencing sensitizes NSCLC cells to cisplatinA. The level of TSN protein expression in normal human lung fibroblasts AG06814 and in NSCLC cell lines (A549, H661, U1810 and H23), left panel. Densitometric analysis of the western blotting bands for TSN normalized to β-actin is presented in the right panel. Results shown are the mean ± standard error of the mean of three independent experiments. B. The level of TSN protein expression in 17 pairs of NSCLC tumor (T) tissues and corresponding adjacent normal (N) tissues. Densitometric analysis of the western blotting bands for TSN normalized to β-actin is presented in the lower panel. C. Cleavage of PARP and processing of caspase-9 and -3 in A549 treated as indicated (cispl, 5 μg/ml for 24 hours). GAPDH was used as loading control. D. Caspase-3-like activity (fold change versus control) in A549 cells treated as indicated (cispl, 5 μg/ml for 24 hours). E. Representative DNA histograms displaying genomic DNA fragmentation in A549 cells treated as indicated (cispl, 5 μg/ml for 48 hours). The percentage of cells in sub-G1 fraction is indicated above the marked area in each diagram. F. Colony formation by A549 cells treated as indicated. The results are shown as the mean ± SEM of three independent experiments. P < 0.05. For details see “Materials and Methods” section. All data are representative of three independent experiments.

Mentions: In order to investigate the expression of TSN in lung canCER cells, the level of protein expression was assessed in a panel of NSCLC cell lines (H661, A549, U1810 and H23), in normal lung fibroblasts AG06814 (Fig. 1A) and in clinical samples. Western blot (Fig. 1A, left panel) and densitometric analysis (Fig. 1A, right panel) revealed that the TSN protein was overexpressed (around a two-fold) in all cancerous cells compared to normal lung fibroblasts.


Tudor staphylococcal nuclease drives chemoresistance of non-small cell lung carcinoma cells by regulating S100A11.

Zagryazhskaya A, Surova O, Akbar NS, Allavena G, Gyuraszova K, Zborovskaya IB, Tchevkina EM, Zhivotovsky B - Oncotarget (2015)

Tudor-SN is overexpressed in non-small cell lung cancer cells and patients’ tissues, and its silencing sensitizes NSCLC cells to cisplatinA. The level of TSN protein expression in normal human lung fibroblasts AG06814 and in NSCLC cell lines (A549, H661, U1810 and H23), left panel. Densitometric analysis of the western blotting bands for TSN normalized to β-actin is presented in the right panel. Results shown are the mean ± standard error of the mean of three independent experiments. B. The level of TSN protein expression in 17 pairs of NSCLC tumor (T) tissues and corresponding adjacent normal (N) tissues. Densitometric analysis of the western blotting bands for TSN normalized to β-actin is presented in the lower panel. C. Cleavage of PARP and processing of caspase-9 and -3 in A549 treated as indicated (cispl, 5 μg/ml for 24 hours). GAPDH was used as loading control. D. Caspase-3-like activity (fold change versus control) in A549 cells treated as indicated (cispl, 5 μg/ml for 24 hours). E. Representative DNA histograms displaying genomic DNA fragmentation in A549 cells treated as indicated (cispl, 5 μg/ml for 48 hours). The percentage of cells in sub-G1 fraction is indicated above the marked area in each diagram. F. Colony formation by A549 cells treated as indicated. The results are shown as the mean ± SEM of three independent experiments. P < 0.05. For details see “Materials and Methods” section. All data are representative of three independent experiments.
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Figure 1: Tudor-SN is overexpressed in non-small cell lung cancer cells and patients’ tissues, and its silencing sensitizes NSCLC cells to cisplatinA. The level of TSN protein expression in normal human lung fibroblasts AG06814 and in NSCLC cell lines (A549, H661, U1810 and H23), left panel. Densitometric analysis of the western blotting bands for TSN normalized to β-actin is presented in the right panel. Results shown are the mean ± standard error of the mean of three independent experiments. B. The level of TSN protein expression in 17 pairs of NSCLC tumor (T) tissues and corresponding adjacent normal (N) tissues. Densitometric analysis of the western blotting bands for TSN normalized to β-actin is presented in the lower panel. C. Cleavage of PARP and processing of caspase-9 and -3 in A549 treated as indicated (cispl, 5 μg/ml for 24 hours). GAPDH was used as loading control. D. Caspase-3-like activity (fold change versus control) in A549 cells treated as indicated (cispl, 5 μg/ml for 24 hours). E. Representative DNA histograms displaying genomic DNA fragmentation in A549 cells treated as indicated (cispl, 5 μg/ml for 48 hours). The percentage of cells in sub-G1 fraction is indicated above the marked area in each diagram. F. Colony formation by A549 cells treated as indicated. The results are shown as the mean ± SEM of three independent experiments. P < 0.05. For details see “Materials and Methods” section. All data are representative of three independent experiments.
Mentions: In order to investigate the expression of TSN in lung canCER cells, the level of protein expression was assessed in a panel of NSCLC cell lines (H661, A549, U1810 and H23), in normal lung fibroblasts AG06814 (Fig. 1A) and in clinical samples. Western blot (Fig. 1A, left panel) and densitometric analysis (Fig. 1A, right panel) revealed that the TSN protein was overexpressed (around a two-fold) in all cancerous cells compared to normal lung fibroblasts.

Bottom Line: Lung cancer is the leading cause of cancer-related deaths worldwide.Silencing of TSN was accompanied by a significant decrease in S100A11 expression at both mRNA and protein level.Moreover, silencing of S100A11 stimulated mitochondrial superoxide production, which was decreased by AACOCF(3), as well as N-acetyl-L-cysteine, which also mimicked the effect of PLA(2) inhibitor on NSCLC chemosensitization upon S100A11 silencing.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environmental Medicine, Division of Toxicology, Stockholm, Sweden.

ABSTRACT
Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC), the major lung cancer subtype, is characterized by high resistance to chemotherapy. Here we demonstrate that Tudor staphylococcal nuclease (SND1 or TSN) is overexpressed in NSCLC cell lines and tissues, and is important for maintaining NSCLC chemoresistance. Downregulation of TSN by RNAi in NSCLC cells led to strong potentiation of cell death in response to cisplatin. Silencing of TSN was accompanied by a significant decrease in S100A11 expression at both mRNA and protein level. Downregulation of S100A11 by RNAi resulted in enhanced sensitivity of NSCLC cells to cisplatin, oxaliplatin and 5-fluouracil. AACOCF(3), a phospholipase A(2) (PLA(2)) inhibitor, strongly abrogated chemosensitization upon silencing of S100A11 suggesting that PLA(2) inhibition by S100A11 governs the chemoresistance of NSCLC. Moreover, silencing of S100A11 stimulated mitochondrial superoxide production, which was decreased by AACOCF(3), as well as N-acetyl-L-cysteine, which also mimicked the effect of PLA(2) inhibitor on NSCLC chemosensitization upon S100A11 silencing. Thus, we present the novel TSN-S100A11-PLA(2) axis regulating superoxide-dependent apoptosis, triggered by platinum-based chemotherapeutic agents in NSCLC that may be targeted by innovative cancer therapies.

No MeSH data available.


Related in: MedlinePlus