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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

Chemosensitizing effect of S100A11 on NSCLC cell silencing involves PLA2 activityA. Cleavage of PARP in A549 and U1810 cells treated as indicated (upper panel). GAPDH was used as loading control. Densitometry data (normalized to GAPDH) (lower panel). B. cPLA2 expression in U1810 and A549 cells. GAPDH was used as loading control. C. cPLA2 expression and processing of caspase-3 and -9 in A549 cells treated as indicated. GAPDH was used as loading control. D. Cleavage of PARP and processing of caspase-9 and -3 in A549 cells treated as indicated (20 hours with or without chemotherapeutic agent). GAPDH and a-tubulin were used as loading control (panel showing corresponding GAPDH and a-tubulin bands are presented below the panel demonstrating the protein of interest). Densitometry values (normalized to GAPDH and a-tubulin) are presented above the corresponding western blotting panels. For details see “Materials and Methods” section. The data are representative of three independent experiments.
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Figure 5: Chemosensitizing effect of S100A11 on NSCLC cell silencing involves PLA2 activityA. Cleavage of PARP in A549 and U1810 cells treated as indicated (upper panel). GAPDH was used as loading control. Densitometry data (normalized to GAPDH) (lower panel). B. cPLA2 expression in U1810 and A549 cells. GAPDH was used as loading control. C. cPLA2 expression and processing of caspase-3 and -9 in A549 cells treated as indicated. GAPDH was used as loading control. D. Cleavage of PARP and processing of caspase-9 and -3 in A549 cells treated as indicated (20 hours with or without chemotherapeutic agent). GAPDH and a-tubulin were used as loading control (panel showing corresponding GAPDH and a-tubulin bands are presented below the panel demonstrating the protein of interest). Densitometry values (normalized to GAPDH and a-tubulin) are presented above the corresponding western blotting panels. For details see “Materials and Methods” section. The data are representative of three independent experiments.

Mentions: S100A11 has no intrinsic enzymatic activity, although it can bind to and modulate the activity of numerous cellular proteins [25]. S100A11 interactions were analyzed using Interactive pathway analysis of complex'omics data and S100A11-related pathways involved in apoptosis and cell resistance to cytotoxic treatment were selected for further analysis. In cell cytoplasm S100A11 was reported to interact with Annexin A1 and Annexin A2 [26, 27], known to inhibit phospholipases A2 (PLA2), a superfamily of enzymes involved in arachidonic acid (AA) release [28]. S100A11 was reported to facilitate Annexin A1-mediated inhibition of cytosolic phospholipase A2 (cPLA2) [27], which, among other PLA2 enzymes, in A549 cells was shown to mediate AA release and subsequent formation of its metabolites, which were inhibited by the PLA2 inhibitor, arachidonyl trifluoromethyl ketone (AACOCF3) [29]. Therefore, we investigated the effect of PLA2 inhibition by AACOCF3 on the chemosensitivity of NSCLC cells. In both A549 and U1810 cells, AACOCF3 significantly suppressed apoptosis, triggered by 24 hours cisplatin treatment (AACOCF3 was added to the cells 1 hour before cisplatin addition), as assessed by the decreased level of cleaved PARP (Fig. 5A, upper panel; densitometric analysis of the presented blots is shown in the lower panel of Fig. 5A). Thus, PLA2 activity, most likely, through increased liberation of AA and/or its metabolites contribute considerably to NSCLC chemosensitivity. cPLA2 may be involved in the AA release in both A549 and U1810 cells, since it is expressed in both cell lines, although at much higher level in A549 cells (Fig. 5B). Silencing of S100A11 may decrease the level of S100A11-Annexin complex and lead to less efficient inhibition of PLA2. Moreover, downregulation of cPLA2 by specific siRNA pool led to diminished apoptotic response of A549 cells to treatment with cisplatin and oxaliplatin (assessed by decreased levels of processed caspase-3 and –9), indicating that cPLA2 activity is involved in the regulation of NSCLC cells’ chemosensitivity (Fig. 5C).


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)

Chemosensitizing effect of S100A11 on NSCLC cell silencing involves PLA2 activityA. Cleavage of PARP in A549 and U1810 cells treated as indicated (upper panel). GAPDH was used as loading control. Densitometry data (normalized to GAPDH) (lower panel). B. cPLA2 expression in U1810 and A549 cells. GAPDH was used as loading control. C. cPLA2 expression and processing of caspase-3 and -9 in A549 cells treated as indicated. GAPDH was used as loading control. D. Cleavage of PARP and processing of caspase-9 and -3 in A549 cells treated as indicated (20 hours with or without chemotherapeutic agent). GAPDH and a-tubulin were used as loading control (panel showing corresponding GAPDH and a-tubulin bands are presented below the panel demonstrating the protein of interest). Densitometry values (normalized to GAPDH and a-tubulin) are presented above the corresponding western blotting panels. For details see “Materials and Methods” section. The data are representative of three independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494929&req=5

Figure 5: Chemosensitizing effect of S100A11 on NSCLC cell silencing involves PLA2 activityA. Cleavage of PARP in A549 and U1810 cells treated as indicated (upper panel). GAPDH was used as loading control. Densitometry data (normalized to GAPDH) (lower panel). B. cPLA2 expression in U1810 and A549 cells. GAPDH was used as loading control. C. cPLA2 expression and processing of caspase-3 and -9 in A549 cells treated as indicated. GAPDH was used as loading control. D. Cleavage of PARP and processing of caspase-9 and -3 in A549 cells treated as indicated (20 hours with or without chemotherapeutic agent). GAPDH and a-tubulin were used as loading control (panel showing corresponding GAPDH and a-tubulin bands are presented below the panel demonstrating the protein of interest). Densitometry values (normalized to GAPDH and a-tubulin) are presented above the corresponding western blotting panels. For details see “Materials and Methods” section. The data are representative of three independent experiments.
Mentions: S100A11 has no intrinsic enzymatic activity, although it can bind to and modulate the activity of numerous cellular proteins [25]. S100A11 interactions were analyzed using Interactive pathway analysis of complex'omics data and S100A11-related pathways involved in apoptosis and cell resistance to cytotoxic treatment were selected for further analysis. In cell cytoplasm S100A11 was reported to interact with Annexin A1 and Annexin A2 [26, 27], known to inhibit phospholipases A2 (PLA2), a superfamily of enzymes involved in arachidonic acid (AA) release [28]. S100A11 was reported to facilitate Annexin A1-mediated inhibition of cytosolic phospholipase A2 (cPLA2) [27], which, among other PLA2 enzymes, in A549 cells was shown to mediate AA release and subsequent formation of its metabolites, which were inhibited by the PLA2 inhibitor, arachidonyl trifluoromethyl ketone (AACOCF3) [29]. Therefore, we investigated the effect of PLA2 inhibition by AACOCF3 on the chemosensitivity of NSCLC cells. In both A549 and U1810 cells, AACOCF3 significantly suppressed apoptosis, triggered by 24 hours cisplatin treatment (AACOCF3 was added to the cells 1 hour before cisplatin addition), as assessed by the decreased level of cleaved PARP (Fig. 5A, upper panel; densitometric analysis of the presented blots is shown in the lower panel of Fig. 5A). Thus, PLA2 activity, most likely, through increased liberation of AA and/or its metabolites contribute considerably to NSCLC chemosensitivity. cPLA2 may be involved in the AA release in both A549 and U1810 cells, since it is expressed in both cell lines, although at much higher level in A549 cells (Fig. 5B). Silencing of S100A11 may decrease the level of S100A11-Annexin complex and lead to less efficient inhibition of PLA2. Moreover, downregulation of cPLA2 by specific siRNA pool led to diminished apoptotic response of A549 cells to treatment with cisplatin and oxaliplatin (assessed by decreased levels of processed caspase-3 and –9), indicating that cPLA2 activity is involved in the regulation of NSCLC cells’ chemosensitivity (Fig. 5C).

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