TY - JOUR
T1 - Radiation-induced TNFα cross signaling-dependent nuclear import of NFκB favors metastasis in neuroblastoma
AU - Aravindan, Sheeja
AU - Natarajan, Mohan
AU - Herman, Terence S.
AU - Aravindan, Natarajan
N1 - Funding Information:
Acknowledgments The authors were supported by National Institutes of Health (COBRE-1P20GM103639-01), American Cancer Society (Grant ACS-IRG-05-066-01), research development funds from the Department of Radiation Oncology at University of Oklahoma Health Sciences Center to N. Aravindan and the National Aeronautics and Space Administration (NASA) Ground-Based Studies in Space Radiobiology, Grant NNX12-AC32G to M. Natarajan.
PY - 2013/8
Y1 - 2013/8
N2 - Ascertaining function-specific orchestration of NFκB in response to radiation may reveal a molecular blue-print that dictates induced relapse and metastasis of the neuroblastoma. We recently demonstrated that sustained activation of NFκB caused by ionizing radiation (IR)-initiated TNFα-NFκB feedback signaling leads to radioresistance and recurrence of neuroblastoma. We investigated whether muting IR-triggered or TNFα-dependent second-signaling feedback-dependent NFκB nuclear import results in limiting IR-altered invasion and metastasis. Neuroblastoma cells were exposed to 2 Gy and incubated for 1 h or 24 h. The cells were then treated with an NFκB-targeting peptide blocker, SN50. Upon confirming the blockade in DNA-binding activity, transcription driven transactivation of NFκB and secretion of soluble TNFα, transcriptional alterations of 93 tumor invasion/metastasis genes were assessed by using QPCR profiling and then were selectively validated at the protein level. Exposure to 2 Gy induced 63, 42 and 71 genes in surviving SH-SY5Y, IMR-32 and SK-N-MC cells, respectively. Blocking post-translational nuclear import of NFκB comprehensively inhibited both initial activation of genes (62/63, 34/42 and 65/71) triggered by IR and also TNFα-mediated second signaling-dependent sustained (59/63, 32/42 and 71/71) activation of tumor invasion and metastasis signaling molecules. Furthermore, alterations in the proteins MMP9, MMP2, PYK-2, SPA-1, Dnmt3b, Ask-1, CTGF, MMP10, MTA-2, NF-2, E-Cadherin, TIMP-2 and ADAMTS1 and the results of our scratch-wound assay validate the role of post-translational NFκB in IR-regulated invasion/metastasis. These data demonstrate that IR-induced second-phase (post-translational) NFκB activation mediates TNFα-dependent second signaling and further implies that IR induced NFκB in cells that survive after treatment regulates tumor invasion/metastasis signaling.
AB - Ascertaining function-specific orchestration of NFκB in response to radiation may reveal a molecular blue-print that dictates induced relapse and metastasis of the neuroblastoma. We recently demonstrated that sustained activation of NFκB caused by ionizing radiation (IR)-initiated TNFα-NFκB feedback signaling leads to radioresistance and recurrence of neuroblastoma. We investigated whether muting IR-triggered or TNFα-dependent second-signaling feedback-dependent NFκB nuclear import results in limiting IR-altered invasion and metastasis. Neuroblastoma cells were exposed to 2 Gy and incubated for 1 h or 24 h. The cells were then treated with an NFκB-targeting peptide blocker, SN50. Upon confirming the blockade in DNA-binding activity, transcription driven transactivation of NFκB and secretion of soluble TNFα, transcriptional alterations of 93 tumor invasion/metastasis genes were assessed by using QPCR profiling and then were selectively validated at the protein level. Exposure to 2 Gy induced 63, 42 and 71 genes in surviving SH-SY5Y, IMR-32 and SK-N-MC cells, respectively. Blocking post-translational nuclear import of NFκB comprehensively inhibited both initial activation of genes (62/63, 34/42 and 65/71) triggered by IR and also TNFα-mediated second signaling-dependent sustained (59/63, 32/42 and 71/71) activation of tumor invasion and metastasis signaling molecules. Furthermore, alterations in the proteins MMP9, MMP2, PYK-2, SPA-1, Dnmt3b, Ask-1, CTGF, MMP10, MTA-2, NF-2, E-Cadherin, TIMP-2 and ADAMTS1 and the results of our scratch-wound assay validate the role of post-translational NFκB in IR-regulated invasion/metastasis. These data demonstrate that IR-induced second-phase (post-translational) NFκB activation mediates TNFα-dependent second signaling and further implies that IR induced NFκB in cells that survive after treatment regulates tumor invasion/metastasis signaling.
KW - NFκB-TNFα feedback
KW - Neuroblastoma
KW - QPCR profiling
KW - Second signaling
KW - Tumor invasion/metastasis
UR - http://www.scopus.com/inward/record.url?scp=84887096321&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84887096321&partnerID=8YFLogxK
U2 - 10.1007/s10585-013-9580-y
DO - 10.1007/s10585-013-9580-y
M3 - Article
C2 - 23584794
AN - SCOPUS:84887096321
SN - 0262-0898
VL - 30
SP - 807
EP - 817
JO - Clinical and Experimental Metastasis
JF - Clinical and Experimental Metastasis
IS - 6
ER -