A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells

The activation of signal transducer and activator of transcription 3 (STAT3) has been identified as a key mediator that drives the fundamental components of melanoma malignancy, including immune suppression in melanoma patients. Increasing evidence also suggests that regulatory T cells (Tregs) are i...

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Main Author: Abou-Ghazal, Mohamed K. (author)
Other Authors: Kong, Ling-Yuan (author), Wei, Jun (author), Sharma, Amit K. (author), Barr, Jason (author), Fokt, Izabela (author), Weinberg, Jeffrey (author), Rao, Ganesh (author), Grimm, Elizabeth (author), Priebe, Waldemar (author), Heimberger, Amy B. (author)
Format: article
Published: 2008
Online Access:http://hdl.handle.net/10725/6475
http://libraries.lau.edu.lb/research/laur/terms-of-use/articles.php
https://link.springer.com/article/10.1007/s00262-008-0618-y
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author Abou-Ghazal, Mohamed K.
author2 Kong, Ling-Yuan
Wei, Jun
Sharma, Amit K.
Barr, Jason
Fokt, Izabela
Weinberg, Jeffrey
Rao, Ganesh
Grimm, Elizabeth
Priebe, Waldemar
Heimberger, Amy B.
author2_role author
author
author
author
author
author
author
author
author
author
author_facet Abou-Ghazal, Mohamed K.
Kong, Ling-Yuan
Wei, Jun
Sharma, Amit K.
Barr, Jason
Fokt, Izabela
Weinberg, Jeffrey
Rao, Ganesh
Grimm, Elizabeth
Priebe, Waldemar
Heimberger, Amy B.
author_role author
dc.creator.none.fl_str_mv Abou-Ghazal, Mohamed K.
Kong, Ling-Yuan
Wei, Jun
Sharma, Amit K.
Barr, Jason
Fokt, Izabela
Weinberg, Jeffrey
Rao, Ganesh
Grimm, Elizabeth
Priebe, Waldemar
Heimberger, Amy B.
dc.date.none.fl_str_mv 2008
2017-11-02T07:55:37Z
2017-11-02T07:55:37Z
2017-11-02
dc.identifier.none.fl_str_mv 1432-0851
http://hdl.handle.net/10725/6475
Kong, L. Y., Wei, J., Sharma, A. K., Barr, J., Abou-Ghazal, M. K., Fokt, I., ... & Heimberger, A. B. (2009). A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells. Cancer immunology, immunotherapy, 58(7), 1023-1032.
http://libraries.lau.edu.lb/research/laur/terms-of-use/articles.php
https://link.springer.com/article/10.1007/s00262-008-0618-y
dc.language.none.fl_str_mv en
dc.relation.none.fl_str_mv Cancer Immunology, Immunotherapy
dc.rights.*.fl_str_mv info:eu-repo/semantics/openAccess
dc.title.none.fl_str_mv A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells
dc.type.none.fl_str_mv Article
info:eu-repo/semantics/publishedVersion
info:eu-repo/semantics/article
description The activation of signal transducer and activator of transcription 3 (STAT3) has been identified as a key mediator that drives the fundamental components of melanoma malignancy, including immune suppression in melanoma patients. Increasing evidence also suggests that regulatory T cells (Tregs) are important in suppressing anti-tumor immunity and play a dominant role in negating efficacious immunotherapy approaches. We hypothesized that WP1066, a novel inhibitor of STAT3 signaling, reverses immune suppression through the inhibition of Tregs and that this contributes to the antitumor activity of this agent against melanoma brain metastases. We found that the mean percentage of peripheral blood mononuclear cells expressing phosphorylated STAT3 (p-STAT3) was significantly elevated in samples from patients with melanoma brain metastases compared to healthy donors, 16.13 ± 2.48% versus 4.17 ± 1.79%. The p-STAT3 inhibitor WP1066 enhanced CD3+ (which contained Tregs) but not CD8+ T cell cytotoxicity against human A375 melanoma cells, indicating that this p-STAT3 blockade agent did not directly activate CD8+ T cells. Furthermore, the p-STAT3 inhibitor did not enhance the cytotoxicity of CD3+CD25− T cells (from which Tregs were excluded), indicating that the enhanced cytotoxicity of WP1066 is secondary to its inhibition of Tregs. This was confirmed by demonstrating that WP1066 inhibited FoxP3+ Treg induction in a dose-dependent manner. Moreover, CD3+ T cells exhibited markedly enhanced levels of phosphorylated ZAP-70, a critical proximal signal in T cell activation, after exposure to WP1066. Similar effects were not observed in Treg-depleted CD3+CD25− T cell populations, confirming that the T cell activation by WP compounds is secondary to their inhibition of the Tregs. These results suggest that WP1066 enhances T cell cytotoxicity against melanoma through inhibition of Tregs.
eu_rights_str_mv openAccess
format article
id LAURepo_ea737c20480b1a8d66a47022418e0e47
identifier_str_mv 1432-0851
Kong, L. Y., Wei, J., Sharma, A. K., Barr, J., Abou-Ghazal, M. K., Fokt, I., ... & Heimberger, A. B. (2009). A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells. Cancer immunology, immunotherapy, 58(7), 1023-1032.
language_invalid_str_mv en
network_acronym_str LAURepo
network_name_str Lebanese American University repository
oai_identifier_str oai:laur.lau.edu.lb:10725/6475
publishDate 2008
repository.mail.fl_str_mv
repository.name.fl_str_mv
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spelling A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cellsAbou-Ghazal, Mohamed K.Kong, Ling-YuanWei, JunSharma, Amit K.Barr, JasonFokt, IzabelaWeinberg, JeffreyRao, GaneshGrimm, ElizabethPriebe, WaldemarHeimberger, Amy B.The activation of signal transducer and activator of transcription 3 (STAT3) has been identified as a key mediator that drives the fundamental components of melanoma malignancy, including immune suppression in melanoma patients. Increasing evidence also suggests that regulatory T cells (Tregs) are important in suppressing anti-tumor immunity and play a dominant role in negating efficacious immunotherapy approaches. We hypothesized that WP1066, a novel inhibitor of STAT3 signaling, reverses immune suppression through the inhibition of Tregs and that this contributes to the antitumor activity of this agent against melanoma brain metastases. We found that the mean percentage of peripheral blood mononuclear cells expressing phosphorylated STAT3 (p-STAT3) was significantly elevated in samples from patients with melanoma brain metastases compared to healthy donors, 16.13 ± 2.48% versus 4.17 ± 1.79%. The p-STAT3 inhibitor WP1066 enhanced CD3+ (which contained Tregs) but not CD8+ T cell cytotoxicity against human A375 melanoma cells, indicating that this p-STAT3 blockade agent did not directly activate CD8+ T cells. Furthermore, the p-STAT3 inhibitor did not enhance the cytotoxicity of CD3+CD25− T cells (from which Tregs were excluded), indicating that the enhanced cytotoxicity of WP1066 is secondary to its inhibition of Tregs. This was confirmed by demonstrating that WP1066 inhibited FoxP3+ Treg induction in a dose-dependent manner. Moreover, CD3+ T cells exhibited markedly enhanced levels of phosphorylated ZAP-70, a critical proximal signal in T cell activation, after exposure to WP1066. Similar effects were not observed in Treg-depleted CD3+CD25− T cell populations, confirming that the T cell activation by WP compounds is secondary to their inhibition of the Tregs. These results suggest that WP1066 enhances T cell cytotoxicity against melanoma through inhibition of Tregs.PublishedN/A2017-11-02T07:55:37Z2017-11-02T07:55:37Z20082017-11-02Articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article1432-0851http://hdl.handle.net/10725/6475Kong, L. Y., Wei, J., Sharma, A. K., Barr, J., Abou-Ghazal, M. K., Fokt, I., ... & Heimberger, A. B. (2009). A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells. Cancer immunology, immunotherapy, 58(7), 1023-1032.http://libraries.lau.edu.lb/research/laur/terms-of-use/articles.phphttps://link.springer.com/article/10.1007/s00262-008-0618-yenCancer Immunology, Immunotherapyinfo:eu-repo/semantics/openAccessoai:laur.lau.edu.lb:10725/64752021-03-19T10:03:26Z
spellingShingle A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells
Abou-Ghazal, Mohamed K.
status_str publishedVersion
title A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells
title_full A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells
title_fullStr A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells
title_full_unstemmed A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells
title_short A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells
title_sort A novel phosphorylated STAT3 inhibitor enhances T cell cytotoxicity against melanoma through inhibition of regulatory T cells
url http://hdl.handle.net/10725/6475
http://libraries.lau.edu.lb/research/laur/terms-of-use/articles.php
https://link.springer.com/article/10.1007/s00262-008-0618-y