Suppression of STAT3 NH2-terminal domain chemosensitizes medulloblastoma cells by activation of protein inhibitor of activated STAT3 via de-repression by microRNA-21

Sutapa Ray; Donald W Coulter; Shawn D. Gray; Jason A. Sughroue; Shrabasti Roychoudhury; Erin M. Mcintyre; Nagendra K. Chaturvedi; Kishor K Bhakat; Shantaram S Joshi; Timothy R McGuire; John G Sharp

doi:10.1002/mc.22778

Suppression of STAT3 NH₂-terminal domain chemosensitizes medulloblastoma cells by activation of protein inhibitor of activated STAT3 via de-repression by microRNA-21

Sutapa Ray, Donald W Coulter, Shawn D. Gray, Jason A. Sughroue, Shrabasti Roychoudhury, Erin M. Mcintyre, Nagendra K. Chaturvedi, Kishor K Bhakat, Shantaram S Joshi, Timothy R McGuire, John G Sharp

Research output: Contribution to journal › Article › peer-review

13 Scopus citations

Abstract

Medulloblastoma (MB) is a malignant pediatric brain tumor with poor prognosis. Signal transducers and activators of transcription-3 (STAT3) is constitutively activated in MB where it functions as an oncoprotein, mediating cancer progression and metastasis. Here, we have delineated the functional role of activated STAT3 in MB, by using a cell permeable STAT3-NH₂ terminal domain inhibitor (S3-NTDi) that specifically perturbs the structure/function of STAT3. We have implemented several biochemical experiments using human MB tumor microarray (TMA) and pediatric MB cell lines, derived from high-risk SHH-TP53-mutated and MYC-amplified Non-WNT/SHH tumors. Treatment of MB cells with S3-NTDi leads to growth inhibition, cell cycle arrest, and apoptosis. S3-NTDi downregulated expression of STAT3 target genes, delayed migration of MB cells, attenuated epithelial-mesenchymal transition (EMT) marker expressions and reduced cancer stem-cell associated protein expressions in MB-spheres. To elucidate mechanisms, we showed that S3-NTDi induce expression of pro-apoptotic gene, C/EBP-homologous protein (CHOP), and decrease association of STAT3 to the proximal promoter of CCND1 and BCL2. Of note, S3-NTDi downregulated microRNA-21, which in turn, de-repressed Protein Inhibitor of Activated STAT3 (PIAS3), a negative regulator of STAT3 signaling pathway. Furthermore, combination therapy with S3-NTDi and cisplatin significantly decreased highly aggressive MYC-amplified MB cell growth and induced apoptosis by downregulating STAT3 regulated proliferation and anti-apoptotic gene expression. Together, our results revealed an important role of STAT3 in regulating MB pathogenesis. Disruption of this pathway with S3-NTDi, therefore, may serves as a promising candidate for targeted MB therapy by enhancing chemosensitivity of MB cells and potentially improving outcomes in high-risk patients.

Original language	English (US)
Pages (from-to)	536-548
Number of pages	13
Journal	Molecular Carcinogenesis
Volume	57
Issue number	4
DOIs	https://doi.org/10.1002/mc.22778
State	Published - Apr 2018

Keywords

MYC
PIAS3
STAT3
medulloblastoma
miR-21

ASJC Scopus subject areas

Molecular Biology
Cancer Research

Access to Document

10.1002/mc.22778

Cite this

Ray, S., Coulter, D. W., Gray, S. D., Sughroue, J. A., Roychoudhury, S., Mcintyre, E. M., Chaturvedi, N. K., Bhakat, K. K., Joshi, S. S., McGuire, T. R., & Sharp, J. G. (2018). Suppression of STAT3 NH₂-terminal domain chemosensitizes medulloblastoma cells by activation of protein inhibitor of activated STAT3 via de-repression by microRNA-21. Molecular Carcinogenesis, 57(4), 536-548. https://doi.org/10.1002/mc.22778

Ray, S , Coulter, DW, Gray, SD, Sughroue, JA, Roychoudhury, S, Mcintyre, EM, Chaturvedi, NK , Bhakat, KK , Joshi, SS, McGuire, TR & Sharp, JG 2018, 'Suppression of STAT3 NH₂-terminal domain chemosensitizes medulloblastoma cells by activation of protein inhibitor of activated STAT3 via de-repression by microRNA-21', Molecular Carcinogenesis, vol. 57, no. 4, pp. 536-548. https://doi.org/10.1002/mc.22778

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title = "Suppression of STAT3 NH2-terminal domain chemosensitizes medulloblastoma cells by activation of protein inhibitor of activated STAT3 via de-repression by microRNA-21",

abstract = "Medulloblastoma (MB) is a malignant pediatric brain tumor with poor prognosis. Signal transducers and activators of transcription-3 (STAT3) is constitutively activated in MB where it functions as an oncoprotein, mediating cancer progression and metastasis. Here, we have delineated the functional role of activated STAT3 in MB, by using a cell permeable STAT3-NH2 terminal domain inhibitor (S3-NTDi) that specifically perturbs the structure/function of STAT3. We have implemented several biochemical experiments using human MB tumor microarray (TMA) and pediatric MB cell lines, derived from high-risk SHH-TP53-mutated and MYC-amplified Non-WNT/SHH tumors. Treatment of MB cells with S3-NTDi leads to growth inhibition, cell cycle arrest, and apoptosis. S3-NTDi downregulated expression of STAT3 target genes, delayed migration of MB cells, attenuated epithelial-mesenchymal transition (EMT) marker expressions and reduced cancer stem-cell associated protein expressions in MB-spheres. To elucidate mechanisms, we showed that S3-NTDi induce expression of pro-apoptotic gene, C/EBP-homologous protein (CHOP), and decrease association of STAT3 to the proximal promoter of CCND1 and BCL2. Of note, S3-NTDi downregulated microRNA-21, which in turn, de-repressed Protein Inhibitor of Activated STAT3 (PIAS3), a negative regulator of STAT3 signaling pathway. Furthermore, combination therapy with S3-NTDi and cisplatin significantly decreased highly aggressive MYC-amplified MB cell growth and induced apoptosis by downregulating STAT3 regulated proliferation and anti-apoptotic gene expression. Together, our results revealed an important role of STAT3 in regulating MB pathogenesis. Disruption of this pathway with S3-NTDi, therefore, may serves as a promising candidate for targeted MB therapy by enhancing chemosensitivity of MB cells and potentially improving outcomes in high-risk patients.",

keywords = "MYC, PIAS3, STAT3, medulloblastoma, miR-21",

author = "Sutapa Ray and Coulter, {Donald W} and Gray, {Shawn D.} and Sughroue, {Jason A.} and Shrabasti Roychoudhury and Mcintyre, {Erin M.} and Chaturvedi, {Nagendra K.} and Bhakat, {Kishor K} and Joshi, {Shantaram S} and McGuire, {Timothy R} and Sharp, {John G}",

note = "Funding Information: The authors thank the Flow Cytometry, Tissue Science facilities and Advanced Microscopy Core Facilities of University of Nebraska Medical Center for their help in these studies. The authors thank Fred & Pamela Buffett Cancer Center Support Grant (P30CA036727), Pediatric Cancer Research Group Support, State of Nebraska, LB905 (to DC) and NCI/NIH RO1 grant CA148941(to KKB). Publisher Copyright: {\textcopyright} 2017 Wiley Periodicals, Inc.",

year = "2018",

month = apr,

doi = "10.1002/mc.22778",

language = "English (US)",

volume = "57",

pages = "536--548",

journal = "Molecular Carcinogenesis",

issn = "0899-1987",

publisher = "Wiley-Liss Inc.",

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T1 - Suppression of STAT3 NH2-terminal domain chemosensitizes medulloblastoma cells by activation of protein inhibitor of activated STAT3 via de-repression by microRNA-21

AU - Ray, Sutapa

AU - Coulter, Donald W

AU - Gray, Shawn D.

AU - Sughroue, Jason A.

AU - Roychoudhury, Shrabasti

AU - Mcintyre, Erin M.

AU - Chaturvedi, Nagendra K.

AU - Bhakat, Kishor K

AU - Joshi, Shantaram S

AU - McGuire, Timothy R

AU - Sharp, John G

N1 - Funding Information: The authors thank the Flow Cytometry, Tissue Science facilities and Advanced Microscopy Core Facilities of University of Nebraska Medical Center for their help in these studies. The authors thank Fred & Pamela Buffett Cancer Center Support Grant (P30CA036727), Pediatric Cancer Research Group Support, State of Nebraska, LB905 (to DC) and NCI/NIH RO1 grant CA148941(to KKB). Publisher Copyright: © 2017 Wiley Periodicals, Inc.

PY - 2018/4

Y1 - 2018/4

N2 - Medulloblastoma (MB) is a malignant pediatric brain tumor with poor prognosis. Signal transducers and activators of transcription-3 (STAT3) is constitutively activated in MB where it functions as an oncoprotein, mediating cancer progression and metastasis. Here, we have delineated the functional role of activated STAT3 in MB, by using a cell permeable STAT3-NH2 terminal domain inhibitor (S3-NTDi) that specifically perturbs the structure/function of STAT3. We have implemented several biochemical experiments using human MB tumor microarray (TMA) and pediatric MB cell lines, derived from high-risk SHH-TP53-mutated and MYC-amplified Non-WNT/SHH tumors. Treatment of MB cells with S3-NTDi leads to growth inhibition, cell cycle arrest, and apoptosis. S3-NTDi downregulated expression of STAT3 target genes, delayed migration of MB cells, attenuated epithelial-mesenchymal transition (EMT) marker expressions and reduced cancer stem-cell associated protein expressions in MB-spheres. To elucidate mechanisms, we showed that S3-NTDi induce expression of pro-apoptotic gene, C/EBP-homologous protein (CHOP), and decrease association of STAT3 to the proximal promoter of CCND1 and BCL2. Of note, S3-NTDi downregulated microRNA-21, which in turn, de-repressed Protein Inhibitor of Activated STAT3 (PIAS3), a negative regulator of STAT3 signaling pathway. Furthermore, combination therapy with S3-NTDi and cisplatin significantly decreased highly aggressive MYC-amplified MB cell growth and induced apoptosis by downregulating STAT3 regulated proliferation and anti-apoptotic gene expression. Together, our results revealed an important role of STAT3 in regulating MB pathogenesis. Disruption of this pathway with S3-NTDi, therefore, may serves as a promising candidate for targeted MB therapy by enhancing chemosensitivity of MB cells and potentially improving outcomes in high-risk patients.

AB - Medulloblastoma (MB) is a malignant pediatric brain tumor with poor prognosis. Signal transducers and activators of transcription-3 (STAT3) is constitutively activated in MB where it functions as an oncoprotein, mediating cancer progression and metastasis. Here, we have delineated the functional role of activated STAT3 in MB, by using a cell permeable STAT3-NH2 terminal domain inhibitor (S3-NTDi) that specifically perturbs the structure/function of STAT3. We have implemented several biochemical experiments using human MB tumor microarray (TMA) and pediatric MB cell lines, derived from high-risk SHH-TP53-mutated and MYC-amplified Non-WNT/SHH tumors. Treatment of MB cells with S3-NTDi leads to growth inhibition, cell cycle arrest, and apoptosis. S3-NTDi downregulated expression of STAT3 target genes, delayed migration of MB cells, attenuated epithelial-mesenchymal transition (EMT) marker expressions and reduced cancer stem-cell associated protein expressions in MB-spheres. To elucidate mechanisms, we showed that S3-NTDi induce expression of pro-apoptotic gene, C/EBP-homologous protein (CHOP), and decrease association of STAT3 to the proximal promoter of CCND1 and BCL2. Of note, S3-NTDi downregulated microRNA-21, which in turn, de-repressed Protein Inhibitor of Activated STAT3 (PIAS3), a negative regulator of STAT3 signaling pathway. Furthermore, combination therapy with S3-NTDi and cisplatin significantly decreased highly aggressive MYC-amplified MB cell growth and induced apoptosis by downregulating STAT3 regulated proliferation and anti-apoptotic gene expression. Together, our results revealed an important role of STAT3 in regulating MB pathogenesis. Disruption of this pathway with S3-NTDi, therefore, may serves as a promising candidate for targeted MB therapy by enhancing chemosensitivity of MB cells and potentially improving outcomes in high-risk patients.

KW - MYC

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KW - miR-21

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