[Show abstract][Hide abstract] ABSTRACT: Background
Oncolytic herpes simplex virus (HSV) can replicate in and kill cancer cells while sparing the adjacent normal tissue. Hepatocellular carcinoma (HCC) is amongst the most common and lethal cancers, especially in Third World countries. In this study, the cytotoxicity of a third-generation oncolytic HSV, G47Δ, was investigated in different human HCC cell lines and in an immortalized human hepatic cell line. Additionally, subcutaneous models of HCC were established to evaluate the in vivo anti-tumor efficacy of G47Δ.
The HepG2, HepB, SMMC-7721, BEL-7404, and BEL-7405 human HCC cell lines and the HL-7702 human hepatic immortalized cell lines were infected with G47Δ at different multiplicities of infection (MOIs). The viability of infected cells was determined, and the G47Δ replication was identified by X-gal staining for LacZ expression. Two subcutaneous (s.c.) HCC tumor models of HCC were also established in Balb/c nude mice, which were intratumorally(i.t.) treated with either G47Δ or mock virus. Tumor volume and mouse survival times were documented.
More than 95% of the HepG2, Hep3B,and SMMC-7721 HCC cells were killed on by day 5 after infection with a MOI’s of 0.01. For the HL-7702 human hepatic immortalized cells, 100% of the cells were killed on by day 5 after infection with a MOI’s of 0.01. The BEL-7404 HCC cell line was less susceptible with about 70% cells were killed by day 5 after infection with a MOI’s of 0.01. Whereas the BEL-7405 HCC cells were the least susceptible, with only 30% of the cells were killed. Both the SMMC-7721 and BEL-7404 cells form aggressive sc tumor models. G47Δ replicates in the tumors, such that most of the tumors regressed after the G47Δ-treatment, and treated tumor-bearing mice survived much longer than the control animals.
G47Δ effectively kills human HCC cells and an immortalized hepatic cell line at low MOI. Intra-tumor injection of G47Δ can induce a therapeutic effect and prolong the survival of treated mice bearing SMMC-7721 and BEL-7404 subcutaneously (s.c.) tumors. Thus, G47Δ may be useful as a novel therapeutic agent for HCC.
Full-text · Article · Sep 2014 · Cancer Cell International
[Show abstract][Hide abstract] ABSTRACT: Accumulating evidence suggests that breast cancer originates from cancer stem cells (CSCs), which comprise a small percentage of the overall tumor but are highly tumorigenic and pluripotent with unlimited proliferation potential. Furthermore, CSCs are highly resistant to conventional treatment, which may explain certain difficulties in treating cancer with current therapy options. In this study, the third generation oncolytic herpes simplex virus (oHSV) vector G47∆ effectively killed different subtypes of breast cancer cells, with more than 98% of the tumor cells killed by Day 5. Moreover, G47∆ targeted equally non-cancer stem cells (NCSCs) and CSCs which showed resistance to paclitaxel. We demonstrated that G47∆ effectively replicated and spread among CSCs. G47∆ also impaired the self-renewal ability of CSCs, as the viable cells were unable to form secondary tumor spheres. We also showed that G47∆ was able to induce the regression of tumor xenografts in BALB/c nude mice and demonstrated the ability of G47∆ to synergize with paclitaxel by killing both NCSCs and CSCs, suggesting that oHSV may be an effective treatment modality for patients with breast cancer.
[Show abstract][Hide abstract] ABSTRACT: The high prevalence and poor prognosis of breast cancer provides a strong rationale for developing new treatment strategies and preventive and therapeutic agents. Oncolytic replication-competent herpes simplex virus (HSV) can infect tumor cells, replicating and killing the cells by direct cytopathic effect and then spreading within the tumor. Replication of oncolytic HSV leads to the destruction of the infected tumor cell and release of new virions, which are able to infect adjacent cells until potentially all tumor cells are destroyed. In this study, the cytotoxicity of a third-generation oncolytic HSV vector, designated G47Δ, was examined in human breast cancer cell lines, as well as in immortalized and normal breast cells. A pulmonary metastatic model of breast cancer established in Balb/c nude mice was used to evaluate the efficacy of G47Δ treatment. Systemic treatment by intravenous administration of G47Δ for metastatic lung tumors was initiated 14 days after injection of tumor cells. On Day 56, the mice were sacrificed and tumor nodules on the surface of the lung were counted. G47Δ was highly cytotoxic to breast cancer and immortalized breast cells in vitro at low multiplicities of infection (MOI), while normal breast cells remained viable 5 days after infection. In the pulmonary metastatic model, the average number of surface lung tumor nodules in the G47Δ-treated group was approximately 9‑fold less than in the control-treated group. X-gal staining illustrated viral replication and spread in the tumor cells in vitro and in vivo. In conclusion, G47Δ effectively killed human breast cancer cells and immortalized breast cells but not normal breast cells. Systemic administration of G47Δ by tail vein injection was effective in inhibiting the growth of established breast cancer lung metastases.
No preview · Article · Nov 2011 · International Journal of Oncology
[Show abstract][Hide abstract] ABSTRACT: Polymyositis (PM) is a very rare paraneoplastic syndrome in association with breast cancer, here we present a breast cancer patient with a sudden onset of respiratory failure caused by PM. A 47-year-old woman, with a history of a lump in her right breast for 3 months, weakness and anorexia for about 1 month, suddenly presented with respiratory failure and elevated muscle enzymes. Muscle biopsy revealed myositis and breast biopsy was consistent with invasive ductal breast cancer. Decreases of muscle enzyme levels were observed after corticosteroid therapy and the lumpectomy, but the patient died from respiratory failure. A case of respiratory failure caused by breast cancer associated polymyositis was presented. This case server to remind that breast cancer patients with muscle weakness or muscle enzyme elevation may be involved with PM.
No preview · Article · Oct 2010 · Breast Cancer Research and Treatment
[Show abstract][Hide abstract] ABSTRACT: Oncolytic viruses are an innovative therapeutic strategy for cancer, wherein viral replication and cytotoxicity are selective for tumor cells. Here we show the efficacy of systemically administered oncolytic viruses for the treatment of spontaneously arising tumors, specifically the use of oncolytic herpes simplex viruses (HSV) administered i.v. to treat spontaneously developing primary and metastatic prostate cancer in the transgenic TRAMP mouse, which recapitulates human prostate cancer progression. Four administrations of systemically delivered NV1023 virus, an HSV-1/HSV-2 oncolytic recombinant, to TRAMP mice at 12 or 18 weeks of age (presence of prostate adenocarcinoma or metastatic disease, respectively) inhibited primary tumor growth and metastases to lymph nodes. Expression of interleukin 12 (IL-12) from NV1042 virus, a derivative of NV1023, was additionally effective, significantly reducing the frequency of development of prostate cancer and lung metastases, even when the mice were treated after the onset of metastasis at 18 weeks of age. NV1042-infected cells, as detected by 5-bromo-4-chloro-3-indolyl-beta-d-galactopyranoside staining for Lac Z expressed by the virus, were present in prostate tumors 1 week after the final virus injection and viral DNA was detected at 2 weeks after final virus injection by real-time PCR in primary and metastatic tumors but not in liver or blood. No toxicity was observed in any of the treated mice. The efficacy of the IL-12-expressing NV1042 virus in this aggressive prostate cancer model using a clinically relevant treatment paradigm merits its consideration for clinical studies.
[Show abstract][Hide abstract] ABSTRACT: Replication competent oncolytic herpes simplex viruses (HSV) are effective agents against a wide spectrum of cancers, including prostate cancer. We have previously evaluated the efficacy of NV1023, a second-generation oncolytic herpes viral mutant of NV1020 for prostate cancer, using the poorly immunogenic TRAMP-C2 tumor model. NV1020, which was recently tested for safety in phase I clinical trial for metastatic liver cancer, contains deletions of one copy of g34.5 and the internal repeat, UL24 and UL56 genes, with addition of gJ, gG, US2 and US3 from HSV-2. NV1023 also has an insertion of LacZ and deletion of the ICP47 and US11 genes. TRAMP-C2 cells are derived from a spontaneously arising prostate adenocarcinoma in TRAMP mouse, in which the SV40 T antigen is under the control of the rat probasin promoter, thus restricting its expression to the epithelial cells of the prostrate. NV1023 was effective when administered intraneoplastically against subcutaneous TRAMP-C2 tumors and when administered intravenously against subcutaneous and metastatic lung TRAMP-C2 tumors.Implanted tumor models, including subcutaneous and lung tumors, are artificial systems with respect to their milieu and lympho-vascular supply and might eventually reflect on the outcome of therapy of being tested. Therefore, we have now used the TRAMP mouse, which develops primary and metastatic prostate cancer spontaneously, to evaluate the efficacy of NV1023. The TRAMP mice mimic the progression of prostate cancer as observed in humans, with the development of prostatic intraepithelial neoplasia by 8-10 weeks, prostate adenocarcinoma by 12 weeks and metastatic cancer to lymph nodes and lung by 18 weeks of age.When administered intravenously into TRAMP mice at 12 weeks of age, NV1023 was significantly more effective as compared to the mock treated mice in inhibiting the growth of primary prostate cancers, based on prostate tumor weight and volume. NV1023 treatment also significantly inhibited metastasis, as determined by the number of mice that displayed metastatic cancers in lymph nodes and lung. Interestingly, when administered at 18-20 weeks, at an age when these mice develop metastasis, the NV1023 virus was significantly effective in primary prostate cancer growth inhibition but not as effective in the frequency of the development of metastatic lymph node and lung tumors. Given the efficacy of NV1023 against spontaneously arising primary and metastatic prostate cancers, NV1023 is appropriate for further testing directed towards a clinical trial for the treatment of prostate cancer in humans.
[Show abstract][Hide abstract] ABSTRACT: Oncolytic herpes simplex virus vectors are a promising strategy for cancer therapy, as direct cytotoxic agents, inducers of antitumor immune responses, and as expressers of anticancer genes. Progress is dependent upon representative preclinical models to evaluate therapy. In this study, two families of oncolytic herpes simplex virus vectors (G207 and NV1020 series) that have been in clinical trials were examined for the treatment of breast cancer, using the C3(1)/T-Ag transgenic mouse model. Female mice spontaneously develop mammary carcinomas, and the C3(1)/T-Ag-derived tumor cell line M6c forms implantable tumors. Both in vitro and in vivo, G47Delta, derived from G207 by deletion of ICP47 and the US11 promoter, was more efficacious than G207. Whereas NV1023, derived from NV1020 by deletion of ICP47 and insertion of LacZ, was as cytotoxic to M6c cells in vitro as G47Delta, it did not inhibit the growth of s.c. M6c tumors but did extend the survival of intracerebral tumor bearing mice. In contrast, NV1042, NV1023 expressing interleukin 12, inhibited s.c. M6c tumor growth to a similar extent as G47Delta, but was less effective than NV1023 in intracerebral tumors. In the spontaneously arising mammary tumor model, when only the first arising tumor per mouse was treated, G47Delta inhibited the growth of a subset of tumors, and when all tumors were treated, G47Delta significantly delayed tumor progression. When the first mammary tumor was treated and the remaining mammary glands removed, NV1042 was more efficacious than G47Delta at inhibiting the growth and progression of injected tumors.
[Show abstract][Hide abstract] ABSTRACT: Breast cancer is the most frequently occurring malignant disease in women with a lifetime risk of 1:8 to 1:10 in the United States. Approximately 20% of breast cancer patients have brain metastases, which are the most important cause of the morbidity and mortality. The blood brain barrier (BBB) separates the brain's interstitial space from the blood and prevents the penetrance of circulating molecules and cells into the brain. This is a significant impediment to systemic delivery in the brain.Oncolytic replication-competent herpes simplex virus (HSV) can infect, replicate and kill tumor cells by a direct cytopathic effect and then spread within the tumor sparing normal cells. G47D is a third generation vector, which has deletions of the g34.5 and a47 genes, and an insertion of E. coli lacZ inactivating the ICP6 gene (ribonucleotide reductase large subunit). As a model for breast cancer metastatic to the brain, we implanted human MDA-MB-435 breast adenocarcinoma cells in the brains of nude mice. These cells are very susceptible to HSV infection and tumors can be treated by oncolytic HSV after intratumoral injection. To obtain systemic delivery of virus, mice bearing brain tumors were injected in the intracarotid artery. BBB disruption (BBBD) was assessed using Evans blue-albumin (68.5 kD, which does not cross the intact BBB) after intracarotid injection of PBS, 25% mannitol or 1.8M arabinose at 0.5ml/s/kg for 20s followed immediately by 2% Evans Blue. As expected, blue staining is restricted to the ipsilateral side of the brain after BBBD with mannitol and arabinosie, but not PBS. Because of toxicity in the arabinose injected mice, we performed the treatment experiments with mannitol BBBD.G47Δ infection and replication was detected by X-gal staining. MDA-MB-435 tumors in the right frontal lobe had extensive X-gal staining if treated with G47D after BBBD, but very few or no staining cells without BBBD. Minimal staining was seen in normal brain tissue and infrequent staining in lung or liver that did not vary with or without BBBD. The mice treated with G47D after BBBD survived significantly longer than Mock (p < 0.0001, Logrank test) or G47D without BBBD (p < 0.02, Logrank test). There was no significant difference in survival between G47D after PBS and Mock after BBBD. In mice with tumor contralateral to the injection side, G47Δ with BBBD did not increase survival. The ability to successfully perform BBBD in mice allows to examine intracarotid artery injection in syngeneic tumor models and transgenic or knockout mice.