Breast cancer is the most common cancer of women in the United States. Despite recent improvements in conventional treatments, advanced breast cancer still has an extremely poor prognosis, resulting in more than 45,000 deaths each year in the US alone. The development of new therapeutic modalities is therefore of great importance. The long-term goal of the research outlined in this proposal is to develop an effective and safe virotherapy for metastatic breast cancer. The central hypothesis is that the antitumor activity of an oncolytic herpes simplex virus (HSV) can be significantly enhanced by incorporating a cell-membrane fusion function into the virus, which will produce syncytia formation in the tumor, thereby directly enhancing the destructive power of the virus and promoting its intratumor spread even in the presence of host's antiviral immunity. The second hypothesize is that the unique mechanism of tumor destruction in vivo by the fusogenic oncolytic HSV can induce strong antitumor immune responses, which can further facilitate tumor eradication.
Specific Aim 1 seeks to determine if a doubly fusogenic oncolytic HSV, which was constructed by incorporating two independent cell-membrane fusion mechanisms into the virus, can provide effective and long-term therapy to distant organ metastases of breast cancer. The safety of this virus will also be fully assessed in this aim.
Specific Aim 2 sets to explore the ability of tumor destruction by the fusogenic oncolytic HSV to induce antitumor immunity. First, the antitumor effect and the accompanying antitumor immunity induced by fusogenic and nonfusogenic oncolytic HSVs will be directly compared in a murine mammary tumor model. Then antibody depletion of immune cells (e.g., CD4+ and CD8+ T cells) will be used to determine if the tumor-specific immune response directly contributes to tumor eradication and which immune cells are responsible for the antitumor immunity. Experiments will also be conducted to dissect the mechanism of enhancement of antitumor immunity by fusogenic oncolytic HSVs.
In Aim 3, the influences of pre-existing antiviral immunity on spread and antitumor effect of fusogenic and non-fusogenic HSVs in metastastic breast will be examined. Then experiments will be conducted to determine if systemic delivery of oncolytic HSV through liposome-formulation of viral DNA or through cell-carriers can evade host's antiviral immunity. The proposed studies will establish a strong preclinical rationale for using the fusogenic oncolytic HSV to treat metastatic breast cancer and will serve as the necessary foundation for a human clinical trial. Finally, if successful in breast cancer, this therapeutic strategy may be applicable to other solid tumors.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA106671-01
Application #
6762241
Study Section
Cancer Immunopathology and Immunotherapy Study Section (CII)
Program Officer
Welch, Anthony R
Project Start
2004-03-01
Project End
2008-02-29
Budget Start
2004-03-01
Budget End
2005-02-28
Support Year
1
Fiscal Year
2004
Total Cost
$246,820
Indirect Cost
Name
Baylor College of Medicine
Department
Pediatrics
Type
Schools of Medicine
DUNS #
051113330
City
Houston
State
TX
Country
United States
Zip Code
77030
Loya, S M W; Zhang, X (2015) Enhancing the bystander killing effect of an oncolytic HSV by arming it with a secretable apoptosis activator. Gene Ther 22:237-46
Fu, Xinping; Rivera, Armando; Tao, Lihua et al. (2013) Genetically modified T cells targeting neovasculature efficiently destroy tumor blood vessels, shrink established solid tumors and increase nanoparticle delivery. Int J Cancer 133:2483-92
Fu, Xinping; Rivera, Armando; Tao, Lihua et al. (2012) Incorporation of the B18R gene of vaccinia virus into an oncolytic herpes simplex virus improves antitumor activity. Mol Ther 20:1871-81
Fu, Xinping; Rivera, Armando; Tao, Lihua et al. (2012) Construction of an oncolytic herpes simplex virus that precisely targets hepatocellular carcinoma cells. Mol Ther 20:339-46
Fu, Xinping; Tao, Lihua; Rivera, Armando et al. (2011) Rapamycin enhances the activity of oncolytic herpes simplex virus against tumor cells that are resistant to virus replication. Int J Cancer 129:1503-10
Fu, X; Tao, L; Rivera, A et al. (2011) Virotherapy induces massive infiltration of neutrophils in a subset of tumors defined by a strong endogenous interferon response activity. Cancer Gene Ther 18:785-94
Fu, Xinping; Tao, Lihua; Rivera, Armando et al. (2010) A simple and sensitive method for measuring tumor-specific T cell cytotoxicity. PLoS One 5:e11867
Fu, Xinping; Tao, Lihua; Zhang, Xiaoliu (2010) A short polypeptide from the herpes simplex virus type 2 ICP10 gene can induce antigen aggregation and autophagosomal degradation for enhanced immune presentation. Hum Gene Ther 21:1687-96
Li, Hongtao; Zeng, Zihua; Fu, Xinping et al. (2007) Coadministration of a herpes simplex virus-2 based oncolytic virus and cyclophosphamide produces a synergistic antitumor effect and enhances tumor-specific immune responses. Cancer Res 67:7850-5
Li, Hongtao; Dutuor, Aurelie; Fu, Xinping et al. (2007) Induction of strong antitumor immunity by an HSV-2-based oncolytic virus in a murine mammary tumor model. J Gene Med 9:161-9

Showing the most recent 10 out of 11 publications