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Proc Natl Acad Sci USA. Targeting CXCL12/CXCR4 signaling with oncolytic virotherapy disrupts tumor vasculature and inhibits breast cancer metastases
[Source: Proceedings of the National Academy of Sciences of the United States of America, full text: (LINK). Abstract, edited.]
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Targeting CXCL12/CXCR4 signaling with oncolytic virotherapy disrupts tumor vasculature and inhibits breast cancer metastases
Margaret Gil<SUP>a</SUP>, Mukund Seshadri<SUP>b</SUP>, Marcin P. Komorowski<SUP>a</SUP>, Scott I. Abrams<SUP>a</SUP>, and Danuta Kozbor<SUP>a</SUP>,<SUP>1</SUP>
<SUP></SUP>
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Author Affiliations: <SUP>a</SUP>Department of Immunology and <SUP>b</SUP>Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263
Edited by Kenneth I. Berns, University of Florida College of Medicine, Gainesville, FL, and approved February 20, 2013 (received for review November 27, 2012)
Significance
Novel advances in viral oncotherapy require effective direct oncolysis and manipulation of the tumor microenvironment, which has proven to be an important target in cancer treatment. The CXCR4 receptor for the CXCL12 chemokine is one of the key stimuli involved in signaling interactions between tumor cells and their microenvironment, suggesting that inhibition of this pathway by oncolytic viruses expressing the CXCR4 antagonist should increase efficacy over that mediated by oncolysis alone. We are unique in demonstrating that targeting CXCR4 signaling through an oncolytic vaccinia virus yields a significant therapeutic impact against primary and metastatic breast cancer.
Abstract
Oncolytic viruses hold promise for the treatment of cancer, but their interaction with the tumor microenvironment needs to be elucidated for optimal tumor cell killing. Because the CXCR4 receptor for the stromal cell-derived factor-1 (SDF-1/CXCL12) chemokine is one of the key stimuli involved in signaling interactions between tumor cells and their stromal microenvironment, we used oncolytic virotherapy with a CXCR4 antagonist to target the CXCL12/CXCR4 signaling axis in a triple-negative 4T1 breast carcinoma in syngeneic mice. We show here that CXCR4 antagonist expression from an oncolytic vaccinia virus delivered intravenously to mice with orthotopic tumors attains higher intratumoral concentration than its soluble counterpart and exhibits increased efficacy over that mediated by oncolysis alone. A systemic delivery of the armed virus after resection of the primary tumor was efficacious in inhibiting the development of spontaneous metastasis and increased overall tumor-free survival. Inhibition of tumor growth with the armed virus was associated with destruction of tumor vasculature, reductions in expression of CXCL12 and VEGF, and decrease in intratumoral numbers of bone marrow-derived endothelial and myeloid cells. These changes led to induction of antitumor antibody responses and resistance to tumor rechallenge. Engineering an oncolytic virus armed with a CXCR4 antagonist represents an innovative strategy that targets multiple elements within the tumor microenvironment. As such, this approach could have a significant therapeutic impact against primary and metastatic breast cancer.
viral oncotherapy - vascular targeting
Footnotes
<SUP>1</SUP>To whom correspondence should be addressed. E-mail: Danuta.Kozbor@roswellpark.org.
Author contributions: M.G., M.S., S.I.A., and D.K. designed research; M.G. and M.P.K. performed research; M.G., M.S., M.P.K., S.I.A., and D.K. analyzed data; and M.G., M.S., S.I.A., and D.K. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1220580110/-/DCSupplemental.
-Margaret Gil<SUP>a</SUP>, Mukund Seshadri<SUP>b</SUP>, Marcin P. Komorowski<SUP>a</SUP>, Scott I. Abrams<SUP>a</SUP>, and Danuta Kozbor<SUP>a</SUP>,<SUP>1</SUP>
<SUP></SUP>
<SUP></SUP>
Author Affiliations: <SUP>a</SUP>Department of Immunology and <SUP>b</SUP>Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263
Edited by Kenneth I. Berns, University of Florida College of Medicine, Gainesville, FL, and approved February 20, 2013 (received for review November 27, 2012)
Significance
Novel advances in viral oncotherapy require effective direct oncolysis and manipulation of the tumor microenvironment, which has proven to be an important target in cancer treatment. The CXCR4 receptor for the CXCL12 chemokine is one of the key stimuli involved in signaling interactions between tumor cells and their microenvironment, suggesting that inhibition of this pathway by oncolytic viruses expressing the CXCR4 antagonist should increase efficacy over that mediated by oncolysis alone. We are unique in demonstrating that targeting CXCR4 signaling through an oncolytic vaccinia virus yields a significant therapeutic impact against primary and metastatic breast cancer.
Abstract
Oncolytic viruses hold promise for the treatment of cancer, but their interaction with the tumor microenvironment needs to be elucidated for optimal tumor cell killing. Because the CXCR4 receptor for the stromal cell-derived factor-1 (SDF-1/CXCL12) chemokine is one of the key stimuli involved in signaling interactions between tumor cells and their stromal microenvironment, we used oncolytic virotherapy with a CXCR4 antagonist to target the CXCL12/CXCR4 signaling axis in a triple-negative 4T1 breast carcinoma in syngeneic mice. We show here that CXCR4 antagonist expression from an oncolytic vaccinia virus delivered intravenously to mice with orthotopic tumors attains higher intratumoral concentration than its soluble counterpart and exhibits increased efficacy over that mediated by oncolysis alone. A systemic delivery of the armed virus after resection of the primary tumor was efficacious in inhibiting the development of spontaneous metastasis and increased overall tumor-free survival. Inhibition of tumor growth with the armed virus was associated with destruction of tumor vasculature, reductions in expression of CXCL12 and VEGF, and decrease in intratumoral numbers of bone marrow-derived endothelial and myeloid cells. These changes led to induction of antitumor antibody responses and resistance to tumor rechallenge. Engineering an oncolytic virus armed with a CXCR4 antagonist represents an innovative strategy that targets multiple elements within the tumor microenvironment. As such, this approach could have a significant therapeutic impact against primary and metastatic breast cancer.
viral oncotherapy - vascular targeting
Footnotes
<SUP>1</SUP>To whom correspondence should be addressed. E-mail: Danuta.Kozbor@roswellpark.org.
Author contributions: M.G., M.S., S.I.A., and D.K. designed research; M.G. and M.P.K. performed research; M.G., M.S., M.P.K., S.I.A., and D.K. analyzed data; and M.G., M.S., S.I.A., and D.K. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1220580110/-/DCSupplemental.
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