Laurence J. Belin

Vaccinia virus GLV-1h153 in combination with 131I shows increased efficiency in treating triple-negative breast cancer

We investigated the therapeutic efficacy of a replication‐competent oncolytic vaccinia virus, GLV‐1h153, carrying human sodium iodide symporter (hNIS), in combination with radioiodine in an orthotopic triple‐negative breast cancer (TNBC) murine model. In vitro viral infection was confirmed by immunoblotting and radioiodine uptake assays. Orthotopic xenografts (MDA‐MB‐231 cells) received intratumoral injection of GLV‐1h153 or PBS. One week after viral injection, xenografts were randomized into 4 treatment groups: GLV‐1h153 alone, GLV‐1h153 and 131I (~5 mCi), 131I alone, or PBS, and followed for tumor growth. Kruskal‐Wallis and Wilcoxon tests were performed for statistical analysis. Radiouptake assay showed a 178‐fold increase of radioiodine uptake in hNIS‐expressing infected cells compared with PBS control. Systemic 131I‐iodide in combination with GLV‐1h153 resulted in a 6‐fold increase in tumor regression (24 compared to 146 mm3 for the virus‐only treatment group; P<0.05; d 40). We demonstrated that a novel vaccinia virus, GLV‐1h153, expresses hNIS, increases the expression of the symporter in TNBC cells, and serves both as a gene marker for noninvasive imaging of virus and as a vehicle for targeted radionuclide therapy with 131I.—Gholami, S., Chen, C‐H., Lou, E., Belin, L. J., Fujisawa, S., Longo, V. A. Chen, N. G., Gönen, M., Zanzonico, P. B., Szalay, A. A., Fong, Y. Vaccinia virus GLV‐1h153 in combination with 131I shows increased efficiency in treating triple‐negative breast cancer. FASEB J. 28, 676–682 (2014). www.fasebj.org

Vaccinia virus GLV-1h153 is a novel agent for detection and effective local control of positive surgical margins for breast cancer

IntroductionSurgery is currently the definitive treatment for early-stage breast cancer. However, the rate of positive surgical margins remains unacceptably high. The human sodium iodide symporter (hNIS) is a naturally occurring protein in human thyroid tissue, which enables cells to concentrate radionuclides. The hNIS has been exploited to image and treat thyroid cancer. We therefore investigated the potential of a novel oncolytic vaccinia virus GLV1h-153 engineered to express the hNIS gene for identifying positive surgical margins after tumor resection via positron emission tomography (PET). Furthermore, we studied its role as an adjuvant therapeutic agent in achieving local control of remaining tumors in an orthotopic breast cancer model.MethodsGLV-1h153, a replication-competent vaccinia virus, was tested against breast cancer cell lines at various multiplicities of infection (MOIs). Cytotoxicity and viral replication were determined. Mammary fat pad tumors were generated in athymic nude mice. To determine the utility of GLV-1h153 in identifying positive surgical margins, 90% of the mammary fat pad tumors were surgically resected and subsequently injected with GLV-1h153 or phosphate buffered saline (PBS) in the surgical wound. Serial Focus 120 microPET images were obtained six hours post-tail vein injection of approximately 600 μCi of 124I-iodide.ResultsViral infectivity, measured by green fluorescent protein (GFP) expression, was time- and concentration-dependent. All cell lines showed less than 10% of cell survival five days after treatment at an MOI of 5. GLV-1h153 replicated efficiently in all cell lines with a peak titer of 27 million viral plaque forming units (PFU) ( <10,000-fold increase from the initial viral dose ) by Day 4. Administration of GLV-1h153 into the surgical wound allowed positive surgical margins to be identified via PET scanning. In vivo, mean volume of infected surgically resected residual tumors four weeks after treatment was 14 mm3 versus 168 mm3 in untreated controls (P < 0.05).ConclusionsThis is the first study to our knowledge to demonstrate a novel vaccinia virus carrying hNIS as an imaging tool in identifying positive surgical margins of breast cancers in an orthotopic murine model. Moreover, our results suggest that GLV-1h153 is a promising therapeutic agent in achieving local control for positive surgical margins in resected breast tumors.

Oncolytic immunotherapy using recombinant vaccinia virus GLV-1h68 kills sorafenib-resistant hepatocellular carcinoma efficiently

BACKGROUND Sorafenib is the standard systemic therapy for unresectable or recurrent hepatocellular carcinoma (HCC) but adds minimal increase in survival. Therefore, there is a great need to develop novel therapies for advanced or recurrent HCC. One emerging field of cancer treatment involves oncolytic viruses that specifically infect, replicate within, and kill cancer cells. In this study, we examined the ability of GLV-1h68, a recombinant vaccinia virus derived from the vaccine strain that was used to eradicate smallpox, to kill sorafenib-resistant (SR) HCC cell lines. METHODS Four SR HCC cell lines were generated by repeated passage in the presence of sorafenib. Median inhibitory concentration was determined for all cell lines. The infectivity, viral replication, and cytotoxicity of GLV-1h68 were assayed for both parental and SR HCC cells. RESULTS Infectivity increased in a time and concentration-dependent manner in all cell lines. All cell lines supported efficient replication of virus. No difference between the rates of cell death between the parental and SR cell lines was observed. CONCLUSION Our results demonstrate that the oncolytic vaccinia virus GLV-1h68 kills both parental and SR HCC cell lines efficiently. This study indicates that patients who have failed treatment with sorafenib remain viable candidates for oncolytic therapy.

Oncolytic gene therapy with recombinant vaccinia strain GLV-2b372 efficiently kills hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma (HCC) commonly presents at a late stage when surgery is no longer a curative option. As such, novel therapies for advanced HCC are needed. Oncolytic viruses are a viable option for cancer therapy owing to their ability to specifically infect, replicate within, and kill cancer cells. In this study, we have investigated the ability of GLV-2b372, a novel light-emitting recombinant vaccinia virus derived from a wild-type Lister strain, to kill HCC. METHODS Four human HCC cell lines were assayed in vitro for infectivity and cytotoxicity. Viral replication was quantified via standard viral plaque assays. Flank HCC xenografts generated in athymic nude mice were treated with intratumoral GLV-2b372 to assess for tumor growth inhibition and viral biodistribution. RESULTS Infectivity occurred in a time- and concentration-dependent manner with 70% cell death in all cell lines by day 5. All cell lines supported efficient viral replication. At 25 days after infection, flank tumor volumes decreased by 50% whereas controls increased by 400%. Tumor tissue demonstrated substantial GLV-2b372 infection at 24 hours, 48 hours, and 2 weeks. CONCLUSION We demonstrate that GLV-2b372 efficiently kills human HCC in vitro and in vivo and is a viable treatment option for patients with HCC.

Gene therapy using therapeutic and diagnostic recombinant oncolytic vaccinia virus GLV-1h153 for management of colorectal peritoneal carcinomatosis.

BACKGROUND Peritoneal carcinomatosis (PC) is a terminal progression of colorectal cancer (CRC). Poor response to cytoreductive operation and chemotherapy coupled with the inability to reliably track disease progression by the use of established diagnostic methods, make this a deadly disease. We examined the effectiveness of the oncolytic vaccinia virus GLV-1h153 as a therapeutic and diagnostic vehicle. We believe that viral expression of the human sodium iodide transporter (hNIS) provides both real-time monitoring of viral therapy and effective treatment of colorectal peritoneal carcinomatosis (CRPC). METHODS Infectivity and cytotoxic effect of GLV-1h153 on CRC cell lines was assayed in vitro. Viral replication was examined by standard viral plaque assays. Orthotopic CRPC xenografts were generated in athymic nude mice and subsequently administered GLV-1h153 intraperitoneally. A decrease in tumor burden was assessed by mass. Orthotopic tumors were visualized by single-photon emission computed tomography/computed tomography after Iodine ((131)I) administration and by fluorescence optical imaging. RESULTS GLV-1h153 infected and killed CRC cells in a time- and concentration-dependent manner. Viral replication demonstrated greater than a 2.35 log increase in titer over 4 days. Intraperitoneal treatment of orthotopic CRPC xenografts resulted in a substantial decrease in tumor burden. Infection of orthotopic xenografts was therapeutic and facilitated monitoring by (131)I-single-photon emission computed tomography/computed tomography via expression of hNIS in infected tissue. CONCLUSION GLV-1h153 kills CRC in vitro effectively and decreases tumor burden in vivo. We demonstrate that GLV-1h153 can be used as an agent to provide accurate delineation of tumor burden in vivo. These findings indicate that GLV-1h153 has potential for use as a therapeutic and diagnostic agent in the treatment of CRPC.

Abstract 5660: Vaccinia virus GLV-1h153 in combination with 131I-iodine shows increased efficiency in treating triple-negative breast cancer in vivo

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL BACKGROUND: Triple-negative breast cancers (TNBC) are aggressive tumors due to their inherent biology and the lack of receptors for hormonal/targeted therapy, namely estrogen, progesterone, and Her2/neu. The human sodium iodide symporter (hNIS) is a naturally occurring protein in some human breast and thyroid tissue which enables cells to concentrate iodine, including radioiodide. In this study, we investigated the therapeutic efficacy of a new oncolytic vaccinia virus, GLV-1h153 carrying the hNIS, in combination with radioiodine in a TNBC murine model. METHODS: GLV-1h153, a replication-competent vaccinia virus, was tested against the TNBC cell lines MDA-MB-231, MDA-MB-468, HCC-1937, and HCC-1143 at multiplicities of infections (MOI) of 0.1, 1.0, and 5. Cytotoxicity and viral replication were determined. Mammary fat pad tumors were generated in athymic nude mice with MDA-MB-231 cells. A subset of xenografts were infected with GLV-1h153 and ∼150 μCi of 124I-iodine was administered. Serial Focus 120 microPET were obtained for 131I dosimetry calculations. For the combination therapy study, 14 days after cell implantation, xenografts were treated with intratumoral injection of GLV-1h153 or PBS. One week after viral injection (day 21), xenografts were further randomized into 4 treatments groups: GLV-1h153 alone, GLV-1h153 and iodine (∼5 mCi of 131I), iodine alone, or PBS and followed for tumor growth. RESULTS: Greater than 90% cell kill was achieved in all cell lines within 5 days at an MOI of 5.0. GLV-1h153 replicated efficiently in all cell lines with a peak titer of 2.6 x107 viral plaque forming units per ml (>1300-fold increase from the initial viral dose) by day 4 in cell line MDA-MB-468. Only infected tumors were identified via PET scanning compared to controls. In vivo, administration of systemic radioiodine in combination with GLV-1h153 resulted in greater tumor regression, 24 mm3 compared to 146 mm3 for the viral-treated group only (p<0.05; days 21-40), a six-fold difference. CONCLUSION: GLV-1h153 infected, replicated in, and killed all TNBC cell lines effectively. This study is the first to our knowledege to demonstrate killing of TNBC by a novel vaccinia virus in combination with radioactive 131I-iodine in an in vivo xenograft model. Our results suggest that GLV-1h153 is a promising therapeutic agent in combination with 131I and merits further testing in the clinical setting. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5660. doi:1538-7445.AM2012-5660