Inhibitory and apoptosis-inducing effects of Newcastle disease virus strain AF2240 on mammary carcinoma cell line. Biomed Res Int. 2015;2015:127828. [PMID: 25821783 PMCID: PMC4363544 DOI: 10.1155/2015/127828]

The NDV-MLS as an Immunotherapeutic Strategy for Breast Cancer: Proof of Concept in Female Companion Dogs with Spontaneous Mammary Cancer

The absence of tumor-infiltrating lymphocytes negatively impacts the response to chemotherapy and prognosis in all subtypes of breast cancer. Therapies that stimulate a proinflammatory environment may help improve the response to standard treatments and also to immunotherapies such as checkpoint inhibitors. Newcastle disease virus (NDV) shows oncolytic activity, as well as immune modulating potential, in the treatment of breast cancer in vitro and in vivo; however, its potential to enhance tumor-infiltrating immune cells in breast cancer has yet to be evaluated. Since spontaneous canine mammary tumors represent a translational model of human breast cancer, we conducted this proof-of-concept study, which could provide a rationale for further investigating NDV-MLS as immunotherapy for mammary cancer. Six female companion dogs with spontaneous mammary cancer received a single intravenous and intratumoral injection of oncolytic NDV-MLS. Immune cell infiltrates were evaluated by histology and immunohistochemistry in the stromal, intratumoral, and peritumoral compartments on day 6 after viral administration. Increasing numbers of immune cells were documented post-viral treatment, mainly in the peritumoral compartment, where plasma cells and CD3+ and CD3-/CD79- lymphocytes predominated. Viral administration was well tolerated, with no significant adverse events. These findings support additional research on the use of NDV-MLS immunotherapy for mammary cancer.

Autophagy inhibition suppresses Newcastle disease virus-induced cell death by inhibiting viral replication in human breast cancer cells

Newcastle disease virus (NDV) is an oncolytic virus which selectively replicates in cancer cells without harming normal cells. Autophagy is a cellular mechanism that breaks down unused cytoplasmic constituents into nutrients. In previous studies, autophagy enhanced NDV-induced oncolysis in lung cancer and glioma cells. However, the effect of autophagy inhibition on NDV-induced oncolysis in breast cancer cells remains unknown. This study aimed to examine the effect of autophagy inhibition on NDV-induced oncolysis in human breast cancer cells, MCF7. To inhibit autophagy, we knocked down the expression of the autophagy protein beclin-1 (BECN1) by short interfering RNA (siRNA). The cells were infected with the recombinant NDV strain AF2240 expressing green fluorescent protein. We found that NDV induced autophagy and knockdown of BECN1 significantly reduced the NDV-induced autophagy in MCF7 cells. Importantly, BECN1 knockdown significantly suppressed cell death by inhibiting viral replication, as observed at 24 h post infection. Overall, our data suggest that autophagy inhibition may not be a suitable strategy to enhance NDV oncolytic efficacy against breast cancer.

Expression Profiles of Immune-Related Genes and Apoptosis Study of Avian Intraepithelial-Natural Killer Cells in Chickens Inoculated with Vaccine Strain of Newcastle Disease Virus (NDV) and Challenged with Virulent NDV

In spite of the available information on the role of natural killer (NK) cells in several viral infections, the interactions between chicken intraepithelial-NK (IEL-NK) cells and Newcastle disease virus (NDV) are poorly understood. In this study, we investigated these interactions following the inoculation of chickens with NDV vaccine strain LaSota and subsequent challenge with velogenic NDV (vNDV) genotype VII (GVII) and VIII (GVIII), through quantification of IEL-NK cell's apoptosis and expression profiling of its surface receptors. Specific-pathogen-free chickens were randomly divided into six groups, as follows: one group of an uninfected control, one group infected with NDV LaSota, two groups each infected with either GVII or GVIII, and two groups inoculated with NDV LaSota and challenged with either GVII (LaSota-genotype VII [LSGVII]) or GVIII (LaSota-genotype VIII [LSGVIII]). Avian intraepithelial lymphocytes (IEL) were isolated from the duodenal loops, and CD3- cells were characterized. Immunophenotyping and apoptosis analysis of CD3-/CD25+/CD45+IEL NK cells were conducted using a flow cytometer. In addition, a gene expression study was conducted using real-time quantitative PCR. Data were analyzed using two-way analysis of variance. The results showed that vNDV GVII or GVIII caused apoptosis of IEL-NK cells; however, following inoculation of LSGVII or LSGVIII, the effect of vNDV GVII and GVIII to cause a reduction in the population of viable IEL-NK cells was significantly reduced. Furthermore, the expression profiles of activating receptors CD69, NK-lysin, and IFN-γ, were generally upregulated in chickens inoculated with LSGVII or LSGVIII. In contrast, B-NK, an inhibitory receptor, was downregulated in these treatment groups. In NDV GVII- and GVIII-challenged groups, however, B-NK was upregulated, whereas the other receptors were generally downregulated. The findings of this study showed that NDV vaccine strain LaSota may prevent apoptosis and cause upregulation of activating receptors of chicken IEL-NK cells in velogenic virus-challenged settings.

Optimization of oncolytic effect of Newcastle disease virus Clone30 by selecting sensitive tumor host and constructing more oncolytic viruses

The direct oncolytic effect of Newcastle disease virus (NDV) depends on the following two aspects: the susceptibility of cancer cells to virus infection and the ability of virus itself to lyse cancer cells. First, we investigate the susceptibility of cancer cells to NDV infection, HepG2, MDA-MB-231, and SH-SY5Y cells were susceptible, A549, MCF7, and LoVo cells were less susceptible. To investigate the molecular mechanism responsible for cancer cell susceptibility, transcriptome sequencing was carried out. We found that the levels of alpha-sialic acid acyltransferase were upregulated in MDA-MB-231 cells compared with MCF7 cells, and the interferon was downregulated. Second, to optimize the oncolytic capacity of the wild-type rClone30, a series of chimeric viruses rClone30-Anh(HN), rClone30-Anh(F), and rClone30-Anh(HN-F) were constructed by exchanging the HN gene, F gene or both of non-lytic rClone30 strain with lytic strain Anhinga. rClone30-Anh(F) and rClone30-Anh(HN-F) enhanced the oncolytic effect of the rClone30, and this enhancement is more obvious in the susceptible cells. The oncolytic mechanism of rClone30-Anh(F) was analyzed by transcriptome analyses, in comparison with rClone30, rClone30-Anh(F) upregulated the expression of ATG5, Beclin 1, and MAP1LC3B, thus activating autophagy and promoting the production of syncytia. In conclusion, our study provides a strategy to enhance the oncolytic effect of rClone30.

Intrinsic Oncolytic Activity of Hoshino Mumps Virus Vaccine Strain Against Human Fibrosarcoma and Cervical Cancer Cell Lines

Background: The use of oncolytic viruses as therapeutic agents is a promising treatment for various human cancers. Several viruses have been extensively examined to achieve tumor cell death. Objectives: This study aimed at evaluating the natural oncolytic activity of mumps Hoshino vaccine strain against two human cancer cell lines, that is, HT1080 fibrosarcoma and HeLa cervical adenocarcinoma cell lines. Methods: The cytolytic activity of the virus was evaluated using an MTT assay. Apoptosis was detected by Annexin-V/propidium iodide (PI) staining and analyzed via flow cytometry. To indicate viral replication in vivo, nude mice with HeLa heterografts were treated with the Hoshino strain of mumps virus. Results: It was found that human fibrosarcoma and cervical cells were more sensitive to the mumps Hoshino strain, even at a very low multiplicity of infection (MOI) compared to normal human diploid cells. The results also showed that the Hoshino strain induced apoptosis in both cancer cells. A preliminary in vivo study revealed the significant suppression of tumor growth in the group treated with the mumps Hoshino strain compared to the control group. Conclusions: The Hoshino vaccine strain of mumps virus showed promising oncolytic activities against human fibrosarcoma and cervical adenocarcinoma cells.

Bta-miR-98 Suppresses Replication of Caprine Parainfluenza Virus Type 3 Through Inhibiting Apoptosis by Targeting Caspase-3

Caprine parainfluenza virus type 3 (CPIV3) is an emerging respiratory pathogen that affects the sheep and goat industry in China and possibly other countries around the world. Accumulating evidence suggests that microRNAs play important roles in regulating virus-host interactions and can suppress or facilitate viral replication. In this study, we showed that CPIV3 infection induced apoptosis in Madin-Darby bovine kidney (MDBK) cells, as determined by morphological changes and flow cytometry. Caspase activity and the expression of pro-apoptotic genes further indicated that CPIV3 induced apoptosis by activating both the intrinsic and extrinsic pathways. We also demonstrated the involvement of bta-microRNA-98 (bta-miR-98) in regulating CPIV3-induced apoptosis. Bta-miR-98 was downregulated in MDBK cells infected with CPIV3. Overexpression of bta-miR-98 significantly decreased the activities of caspase-3, -8, and -9. Conversely, inhibition of bta-miR-98 had completely opposite effects. Furthermore, our data showed that bta-miR-98 markedly affected CPIV3 replication by regulating apoptosis. Importantly, we found that bta-miR-98 modulated CPIV3-induced apoptosis by targeting caspase-3, an effector of apoptosis. Collectively, our results may suggest that CPIV3 infection induced apoptosis and downregulated the levels of bta-miR-98, and this miRNA regulated viral replication through effected apoptosis. This study contributes to our understanding of the molecular mechanisms underlying CPIV3 pathogenesis.

Cytotoxicity study of the interleukin-12-expressing recombinant Newcastle disease virus strain, rAF-IL12, towards CT26 colon cancer cells in vitro and in vivo

Background

Oncolytic viruses have emerged as an alternative therapeutic modality for cancer as they can replicate specifically in tumour cells and induce toxic effects leading to apoptosis. Despite the great potentials and promising results shown in multiple studies, it appears that their efficacy is still moderate and deemed as not sufficient in clinical studies. In addressing this issue, genetic/molecular engineering approach has paved its way to improve the therapeutic efficacy as observed in the case of herpes simplex virus (HSV) expressing granulocyte–macrophage colony-stimulating factor (GM-CSF). This study aimed to explore the cytotoxicity effects of recombinant NDV strain AF2240-i expressing interleukin-12 (rAF-IL12) against CT26 colon cancer cells.

Methods

The cytotoxicity effect of rAF-IL12 against CT26 colon cancer cell line was determined by MTT assay. Based on the IC₅₀ value from the anti-proliferative assay, further downward assays such as Annexin V FITC and cell cycle progression were carried out and measured by flow cytometry. Then, the in vivo study was conducted where the rAF-IL12 viral injections were given at the intra-tumoral site of the CT26 tumour-burden mice. At the end of the experiment, serum biochemical, T cell immunophenotyping, serum cytokine, histopathology of tumour and organ section, TUNEL assay, and Nanostring gene expression analysis were performed.

Results

The rAF-IL12 induced apoptosis of CT26 colon cancer cells in vitro as revealed in the Annexin V FITC analysis and also arrested the cancer cells progression at G₁ phase of the cell cycle analysis. On the other hand, the rAF-IL12 significantly (p < 0.05) inhibited the growth of CT26 tumour in Balb/c mice and had regulated the immune system by increasing the level of CD4 + , CD8 + , IL-2, IL-12, and IFN-γ. Furthermore, the expression level of apoptosis-related genes (bax and p53) was up-regulated as a result of the rAF-IL12 treatment. Additionally, the rAF-IL12 had also down-regulated the expression level of KRAS, BRAF, MAPK1, Notch1, CCL2, and VEGF oncogenes. Besides, rAF-IL12 intra-tumoral delivery was considered safe and not hazardous to the host as evidenced in pathophysiology of the normal tissues and organs of the mice as well as from the serum biochemistry profile of liver and kidney.

Conclusions

These results indicated that rAF-IL12 had better anti-tumoral and cytotoxicity effects compared to its parental wild-type, AF2240-i in combatting the CT26 colon cancer model.

Evaluation of CERS2 Gene as a Potential Biomarker for Bladder Cancer

The ceramide synthase 2 (CERS2) gene has been linked to tumour recurrence and invasion in many different types of cancers including bladder cancer. In this study, the expression levels of CERS2 in bladder cancer cell lines were analysed using qRT-PCR and the protein expression in clinical bladder cancer histopathological specimens were examined via immunohistochemistry. The potential utility of CERS2 as a predictive biomarker of response to oncolytic virotherapy was assessed by correlating the CERS2 mRNA expression to IC₅₀ values of cells treated with the Newcastle disease virus (NDV), AF2240 strain. This study demonstrates that CERS2 is differentially expressed in different types of bladder cancer cell lines and that the siRNA-mediated downregulation of the expression of CERS2 reduces the migratory potential of UMUC1 bladder cancer cells. However, there were no significant correlations between the expression levels of the CERS2 protein with bladder cancer grade/stage or between the IC50 values of cells treated with NDV and CERS2 expression. Although the utility of CERS2 expression may be limited, its potential as an antimigration cancer therapeutic should be further examined.

Application of Newcastle disease virus in the treatment of colorectal cancer

Colorectal cancer (CRC) is one of the main reasons of tumor-related deaths worldwide. At present, the main treatment is surgery, but the results are unsatisfactory, and the prognosis is poor. The majority of patients die due to liver or lung metastasis or recurrence. In recent years, great progress has been made in the field of tumor gene therapy, providing a new treatment for combating CRC. As oncolytic viruses selectively replicate almost exclusively in the cytoplasm of tumor cells and do not require integration into the host genome, they are safer, more effective and more attractive as oncolytic agents. Newcastle disease virus (NDV) is a natural RNA oncolytic virus. After NDV selectively infects tumor cells, the immune response induced by NDV’s envelope protein and intracellular factors can effectively kill the tumor without affecting normal cells. Reverse genetic techniques make NDV a vector for gene therapy. Arming the virus by inserting various exogenous genes or using NDV in combination with immunotherapy can also improve the anti-CRC capacity of NDV, and good results have been achieved in animal models and clinical treatment trials. This article reviews the molecular biological characteristics and oncolytic mechanism of NDV and discusses in vitro and in vivo experiments on NDV anti-CRC capacity and clinical treatment. In conclusion, NDV is an excellent candidate for cancer treatment, but more preclinical studies and clinical trials are needed to ensure its safety and efficacy.

Newcastle disease virus mediated apoptosis and migration inhibition of human oral cancer cells: A probable role of β-catenin and matrix metalloproteinase-7

Cancer cell metastasis and its dissemination are most enigmatic and challenging aspects in the development of its therapeutics. Newcastle disease virus (NDV) is a well-studied avian paramyxovirus frequently isolated from birds and rarely from mammals. Since the first report of its oncolytic property, many NDV strains were studied for its effect in various cancer cells. In the present study, NDV strain Bareilly was characterized for its apoptotic potential and migration inhibition in human oral cancer cells. The NDV mediated apoptosis was confirmed by flow cytometry, DNA laddering, and immunoblotting. Moreover, NDV decreased the mitochondrial membrane potential suggesting an intrinsic pathway of apoptosis in oral cancer cells. NDV infection in oral cancer cells results in migration inhibition by a reduction in levels of MMP-7. MMP-7 is one of the key target genes of β-catenin. While overexpression of MMP-7 reversed the inhibitory effect of NDV mediated migration suggested its possible involvement. Wnt/β-catenin is an essential pathway for cell growth, differentiation, and metastasis. The involvement of the Wnt/β-catenin pathway in NDV infection has never been reported. Our results showed that NDV dysregulates Wnt/β-catenin by down-regulation of p-Akt and p-GSK3β leading to degradation of β-catenin. Furthermore, NDV infection leads to a reduction in cytoplasmic and nuclear levels of β-catenin. The study will provide us with a better insight into the molecular mechanism of NDV mediated oncolysis and the key cellular partners involved in the process.

Regression of solid breast tumours in mice by Newcastle disease virus is associated with production of apoptosis related-cytokines

BACKGROUND

Different strains of Newcastle disease virus (NDV) worldwide proved to have tumouricidal activity in several types of cancer cells. However, the possible anti-cancer activity of Malaysian NDV AF2240 strain and its mechanism of action remains unknown. The ability of cytokine-related apoptosis-inducing NDV AF2240 to treat breast cancer was investigated in the current study.

METHODS

A total of 90 mice were used and divided into 15 groups, each group comprising of 6 mice. Tumour, body weight and mortality of the mice were determined throughout the experiment, to observe the effect of NDV and NDV + tamoxifen treatments on the mice. In addition, the toxic effect of the treatments was determined through liver function test. In order to elucidate the involvement of cytokine production induced by NDV, a total of six cytokines, i.e. IL-6, IFN-γ, MCP-1, IL-10, IL12p70 and TNF-α were measured using cytometric bead array assay (plasma) and enzyme-linked immunosorbent spot (isolated splenocytes).

RESULTS

The results demonstrated that 4 T1 breast cancer cells in allotransplanted mice treated with AF2240 showed a noticeable inhibition of tumour growth and induce apoptotic-related cytokines.

CONCLUSIONS

NDV AF2240 suppression of breast tumour growth is associated with induction of apoptotic-related cytokines. It would be important to further investigate the molecular mechanism underlaying cytokines production by Newcastle disease virus.

Amphotericin B potentiates the anticancer activity of doxorubicin on the MCF-7 breast cancer cells

Despite the improvements in cancer treatment, breast cancer still remains the second most common cause of death from cancer in women. Doxorubicin (DOXO) is widely used for cancer treatment. However, drug resistance limits the treatment outcome. Here, we investigated the toxicity of DOXO in combination with an antifungal agent amphotericin B (AmB) against the MCF-7 breast cancer cell line. The cell viability was measured using MTT assay. The apoptosis was studied by caspase-8 and caspase-9 activity measurements and DNA fragmentation was investigated by TUNEL assay. The combination of two drugs significantly increased the apoptotic index and the caspase-8 and caspase-9 activities in comparison to DOXO-treated cells. Our finding showed that pre-treatment of MCF-7 cells with AmB synergistically exerted the anticancer effect of DOXO through the caspase-dependent apoptosis manner.

The therapeutic effect of death: Newcastle disease virus and its antitumor potential

Programmed cell death is essential to survival of multicellular organisms. Previously restricted to apoptosis, the concept of programmed cell death is now extended to other mechanisms, as programmed necrosis or necroptosis, autophagic cell death, pyroptosis and parthanatos, among others. Viruses have evolved to manipulate and take control over the programmed cell death response, and the infected cell attempts to neutralize viral infections displaying different stress signals and defensive pathways before taking the critical decision of self-destruction. Learning from viruses and their interplay with the host may help us to better understand the complexity of the self-defense death response that when altered might cause disorders as important as cancer. In addition, as the fields of immunotherapy and oncolytic viruses advance as promising novel cancer therapies, the programmed cell death response reemerges as a key point for the success of both therapeutic approaches. In this review we summarize the research of the multimodal cell death response induced by Newcastle disease viruses (NDV), considered nowadays a promising viral oncolytic therapeutic, and how the manipulation of the host programmed cell death response can enhance the NDV antitumor capacity.