Anti-leukemic activity of Newcastle disease virus strains AF2240 and V4-UPM in murine myelomonocytic leukemia in vivo

Oncolytic viruses for triple negative breast cancer and beyond

Biological therapy is considered an alternative treatment capable of eliciting the same effects on tumors as surgery, radiotherapy, and chemotherapy. As a major player in biological therapy, oncolytic viruses (OVs) have attracted great attention and achieved good results. Specifically, the successful application of OVs in head and neck cancer, as well as melanoma, promoted its research in triple negative breast cancer (TNBC). TNBC is a high-risk molecular type of breast cancer, characterized by strong invasion, easy recurrence, and metastasis. Due to the absence of estrogen and progesterone receptors, as well as the absence of overexpression or gene amplification of human epidermal growth factor receptor 2 (HER2), endocrine therapy and anti HER-2 targeted therapy have proven ineffective. Although chemotherapy has shown substantial efficacy in some TNBC patients, the occurrence of drug resistance and poor prognosis have prompted the exploration of new and effective treatment methods. The emerging concept of OVs provides a new platform to treat TNBC. Indeed, several studies have confirmed the therapeutic effects of OVs in TNBC. Numerous studies have also investigated the efficacy of OVs in other malignances, including solid tumor clinical trials, thus further demonstrating the promising application of oncolytic virotherapy for TNBC. The primary focus of the current review is the examination of OV mechanisms underlying their antitumor properties, while also summarizing the ongoing progress in OV research regarding TNBC treatment, as well as the various combinatorial strategies comprising OVs and other therapies. We also briefly introduce specific relevant clinical trials and discuss some of the progress in the research of novel OVs for the treatment of other malignancies, thereby affirming the significant therapeutic potential of OVs for the treatment of TNBC, as well as other cancers.

Application of Emerging Plant-Derived Nanoparticles as a Novel Approach for Nano-Drug Delivery Systems

Nanotechnology has enabled the delivery of small molecular drugs packaged in nanosized vesicles to the target tissues. Plant-Derived Nanoparticles (PDNPs) are vesicles with natural origin and unique properties. These nanoparticles have several advantages over synthetic exosomes and liposomes. They provide bioavailability and biodistribution of therapeutic agents when delivered into different tissues. These nanoparticles can be modified according to the specificity of their functions in target tissues. When PDNPs are internalized, they can induce stem cells proliferation, reduce colitis injury, activate intrinsic and extrinsic apoptosis pathways, and inhibit tumor growth and progression. These properties make them potential drug delivery systems in targeting diseased tissues, such as inflammatory regions and different cancers.

Combinational treatment of 5-fluorouracil and casticin induces apoptosis in mouse leukemia WEHI-3 cells in vitro

Leukemia is one of the major diseases causing cancer-related deaths in the young population, and its cure rate is unsatisfying with side effects on patients. Fluorouracil (5-FU) is currently used as an anticancer drug for leukemia patients. Casticin, a natural polymethoxyflavone, exerts anticancer activity against many human cancer cell lines in vitro, but no other reports show 5-FU combined with casticin increased the mouse leukemia cell apoptosis in vitro. Herein, the antileukemia activity of 5-FU combined with casticin in WEHI-3 mouse leukemia cells was investigated in vitro. Treatment of two-drug combination had a higher decrease in cell viability and a higher increase in apoptotic cell death, the level of DNA condensation, and the length of comet tail than that of 5-FU or casticin treatment alone in WEHI-3 cells. In addition, the two-drug combination has a greater production rate of reactive oxygen species but a lower level of Ca²⁺ release and mitochondrial membrane potential (ΔΨ_m ) than that of 5-FU alone. Combined drugs also induced higher caspase-3 and caspase-8 activities than that of casticin alone and higher caspase-9 activity than that of 5-FU or casticin alone at 48 hours treatment. Furthermore, 5-FU combined with casticin has a higher expression of Cu/Zn superoxide dismutase (SOD [Cu/Zn]) and lower catalase than that of 5-FU or casticin treatment alone. The combined treatment has higher levels of Bax, Endo G, and cytochrome C of proapoptotic proteins than that of casticin alone and induced lower levels of B-cell lymphoma 2 (BCL-2) and BCL-X of antiapoptotic proteins than that of 5-FU or casticin only. Furthermore, the combined treatment had a higher expression of cleaved poly (ADP-ribose) polymerase (PARP) than that of casticin only. Based on these findings, we may suggest that 5-FU combined with casticin treatment increased apoptotic cell death in WEHI-3 mouse leukemia cells that may undergo mitochondria and caspases signaling pathways in vitro.

Liver Pathology in Rats Treated with Newcastle Disease Virus Strains AF2240 and V4-UPM

BACKGROUND

Treatment of cancer with chemo-radiotherapy causes severe side effects due to cytotoxic effects towards normal tissues which often results in morbidity. Therefore, developing anticancer agents which can selectively target the cancer cells and cause less side effects are the main objectives of the new therapeutic strategies for treatment advanced or metastatic cancers. Newcastle disease virus strains AF2240 and V4-UPM were shown to be cytolytic against various cancer cells in-vitro and very effective as antileukemicagents.

METHODS

45 rats at 6 weeks of age, were randomly assigned to nine groups with 5 rats in each group, both azoxymethane (AOM) and 5-Fluorouracil (5-FU) were given to rats according to the body weight. NDV virus strains (AF2240 and V4-UPM) doses were determined to rats according to CD50 resulted from MTT assay. After 8 doses of NDV strians and 5-FU, tissue sections preparations and histopathological study of rats' organs were done.

RESULTS

In this article morphological changes of rats' organs, especially in livers, after treatment with a colon carcinogen (azoxymethane) and Newcastle disease virus strains have been recorded. We observed liver damage caused by AOM evidenced by morphological changes and enzymatic elevation were protected by the oncolytic viruses sections. Also we found that combination treatment NDV with 5-FU had greater antitumor efficacy than treatment with NDV or 5-FU alone.

CONCLUSION

We noted morphological changes in liver and other rats' organs due to a chemical carcinogen and their protection by NDV AF2240 and NDV V4-UPM seems to be most protective.

Fisetin Inhibits Cell Proliferation through the Induction of G0/G1 Phase Arrest and Caspase-3-Mediated Apoptosis in Mouse Leukemia Cells

Fisetin, a naturally occurring flavonoid, is found in common fruits and vegetables and has been shown to induce cytotoxic effects in many human cancer cell lines. No information has shown that fisetin induced cell cycle arrest and apoptosis in mouse leukemia WEHI-3 cells. We found that fisetin decreased total viable cells through G₀/G₁ phase arrest and induced sub-G₁ phase (apoptosis). We have confirmed fisetin induced cell apoptosis by the formation of DNA fragmentation and induction of apoptotic cell death. Results indicated that fisetin induced intracellular Ca 2+ increase but decreased the ROS production and the levels of ΔΨ m in WEHI-3 cells. Fisetin increased the activities of caspase-3, -8 and -9. Cells were pre-treated with inhibitors of caspase-3, -8 and -9 and then treated with fisetin and results showed increased viable cell number when compared to fisetin treated only. Fisetin reduced expressions of cdc25a but increased p-p53, Chk1, p21 and p27 that may lead to G₀/G₁ phase arrest. Fisetin inhibited anti-apoptotic protein Bcl-2 and Bcl-xL and increased pro-apoptotic protein Bax and Bak. Furthermore, fisetin increased the protein expression of cytochrome c and AIF. Fisetin decreased cell number through G₀/G₁ phase arrest via the inhibition of cdc25c and induction of apoptosis through caspase-dependent and mitochondria-dependent pathways. Therefore, fisetin may be useful as a potential therapeutic agent for leukemia.

Ouabain promotes immune responses in WEHI-3 cells to generate leukemia mice through enhancing phagocytosis and natural killer cell activities in vivo

Ouabain, a cardiotonic steroid, was used for the treatment of heart failure and atrial fibrillation and induces cancer cell apoptosis in many human cancer cells including human leukemia cells. However, there are no reports to show the effects on immune responses in a leukemia mouse model. In this study, WEHI-3 cell generated leukemia mice were developed and treated by oral ouabain at 0, 0.75, 1.5, and 3 mg/kg for 15 days. Results indicated that ouabain did not affect body appearance, but decreased liver and spleen weights, B- and T-cell proliferation at all three doses treatment and increased CD19 cells at 3.0 mg/kg treatment, decreased CD3, CD11b, and Mac-3 cells levels compared with positive control. Furthermore, ouabain increased the macrophage phagocytosis from peripheral blood mononuclear cell and peritoneal cavity at all three doses treatment and increased NK cell activities. Ouabain restored GOT, GPT and LDH levels in WEHI-3 leukemia mice in vivo.

Maslinic Acid Enhances Immune Responses in Leukemic Mice Through Macrophage Phagocytosis and Natural Killer Cell Activities In Vivo

BACKGROUND/AIM

Maslinic acid (MA), a pentacyclic triterpene extracted from wax-like coatings of olives, has been shown to reduce cancer cell number through induction of autophagy and apoptosis in many human cancer cells including human leukemia HL-60 cells. In the present study, we investigated whether or not MA affects immune responses in a leukemia mouse model.

MATERIALS AND METHODS

WEHI-3 cells were intraperitonealIy (i.p.) injected into normal BALB/c mice to develop leukemia. Mice were then treated by i.p. injection with MA at different doses (0, 8, 16 and 32 mg/kg) for 2 weeks. After treatment, all animals were weighed and blood, liver and spleen tissues were weighed. Blood or spleen both were used for determination of cell markers or phagocytosis, natural killer (NK) cell activities and T- and B-cell proliferation, respectively, by using a flow cytometric assay.

RESULTS

MA did not significantly affect body, liver, and spleen weights. However, MA increased markers of T-cells (at 16 mg/kg treatment) and monocytes (at 32 mg/kg treatment), but reduced B-cell markers (at 8 mg/kg treatment); MA did not significantly affect cell marker of macrophages. Furthermore, MA increased phagocytosis by macrophages from peripheral blood mononuclear cells and peritoneal cavity at 32 mg/kg treatment and increased NK cell activity at target cell:splenocyte ratio of 25:1 but did not affect B- and T-cell proliferation.

CONCLUSION

MA increased immune responses by enhancing macrophage phagocytosis and NK cell activities in leukemic mice.

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.

Cardamonin Induces Cell Cycle Arrest, Apoptosis and Alters Apoptosis Associated Gene Expression in WEHI-3 Mouse Leukemia Cells

Cardamonin, the chalcone class, is one of the natural components from the spicy herbaceous plant (Alpinia conchigera Griff) and has anticancer activities in many human cancer cell lines. There is, however, no information to show that cardamonin induces cell apoptosis and alters apoptosis associated gene expressions in mouse leukemia cells. Thus, we investigated the effects of cardamonin on the apoptotic cell death and associated gene expression in mouse leukemia WEHI-3 cells in vitro. Results indicated that cardamonin decreased total viable cell number via induced cell morphological changes and apoptotic cell death in WEHI-3 cells that were assay by contrast-phase microscopy and flow cytometry examinations, respectively. The flow cytometry assay indicated that cardamonin increased reactive oxygen species (ROS) and Ca[Formula: see text] production, decreased the levels of mitochondrial membrane potential ([Formula: see text] and increased caspase-3, -8 and -9 activities in WEHI-3 cells. Western blotting was performed to analyze expression of relevant pro- and anti-apoptotic proteins and results showed that cardamonin decreased anti-apoptotic protein of Bcl-2 but increased pro-apoptotic protein of Bax in WEHI-3 cells. Furthermore, cardamonin increased cytochrome c, AIF and Endo G release, increased GRP78, caspase-12 that were associated with ER stress and increased Fas, Fas-Ligand and FADD expression. Furthermore, cardamonin increased the gene expressions of DAP (death-associated protein), TMBIM4 transmembrane (BAX inhibitor motif containing 4), ATG5 (autophagy related 5) but decreased the gene expression of DDIT3 (DNA-damage inducible transcript 3), DDIT4 (DNA-damage-inducible transcript 4), BAG6 (BCL2-associated athanogene 6), BCL2L13 [BCL2-like 13 (apoptosis facilitator)] and BRAT1 (BRCA1-associated ATM activator 1) that are associated with apoptosis pathways. Based on those findings, we may suggest cardamonin induced apoptotic cell death through Fas and Fas-Ligand-, caspase- and mitochondria-dependently pathways and also affects the apoptotic gene expression in WEHI-3 cells in vitro.

Bufalin Enhances Immune Responses in Leukemic Mice Through Enhancing Phagocytosis of Macrophage In Vivo

BACKGROUND/AIM

Bufalin, bufadienolide present in Chan Su, has been shown to induce cancer cell apoptosis in many human cancer cells, including human leukemia cells, but its effects on immune responses are unknown.

MATERIALS AND METHODS

This study investigated whether bufalin affected immune responses of mice with WEHI-3 cell-generated leukemia in vivo. BALB/c mice were intraperitoneally injected with WEHI-3 cells to develop leukemia and then were treated with oral treatment with bufalin at different doses (0, 0.1, 0.2 and 0.4 mg/kg) for 2 weeks. At the end of treatment, all mice were weighted and blood was collected; liver and spleen tissues were collected for cell marker, phagocytosis, natural killer (NK) cell activity and T- and B-cell proliferation measurements by using flow cytometric assays.

RESULTS

When compared with the leukemia control group, bufalin increased the body weight, but reduced liver and spleen weights, and reduced CD3, CD16 and Mac-3 cell markers at 0.4 mg/kg treatment and increased CD11b marker at 0.1 and 0.2 mg/kg treatment. Furthermore, bufalin at 0.4 mg/kg increased phagocytosis by macrophages isolated from peripheral blood mononuclear cells and at 0.1 mg/kg by those from the peritoneal cavity. Bufalin (0.2 and 0.4 mg/kg) increased NK cell cytotoxic activity at effector:target ratio of 50:1. Bufalin increased B-cell proliferation at 0.1 and 0.2 mg/kg treatment but only increased T-cell proliferation at 0.1 mg/kg. Bufalin increased glutamate oxaloacetate transaminase level at all dose treatments, increased glutamic pyruvic transaminase level only at 0.1 mg/kg treatment, but reduced the level of lactate dehydrogenase at all dose levels in mice with WEHI-3 cell-induced leukemia in vivo.

CONCLUSION

Bufalin increased immune responses by enhancing phagocytosis in mice with leukemia mice.

Newcastle disease virus strain AF2240 as an oncolytic virus: A review

The discovery of tumour selective virus-mediated apoptosis marked the birth of an alternative cancer treatment in the form of oncolytic viruses. Even though, its oncolytic efficiency was demonstrated more than 50 years ago, safety concerns which resulted from mild to lethal side effects hampered the progress of oncolytic virus research. Since the classical oncolytic virus studies rely heavily on its natural oncolytic ability, virus manipulation was limited, thereby, restricted efforts to improve its safety. In order to circumvent such restriction, experiments involving non-human viruses such as the avian Newcastle disease virus (NDV) was conducted using cultured cells, animal models and human subjects. The corresponding reports on its significant tumour cytotoxicity along with impressive safety profile initiated immense research interest in the field of oncolytic NDV. The varying degree of oncolytic efficiency and virulency among NDV strains encouraged researchers from all around the world to experiment with their respective local NDV isolates in order to develop an oncolytic virus with desirable characteristics. Such desirable features include high tumour-killing ability, selectivity and low systemic cytotoxicity. The Malaysian field outbreak isolate, NDV strain AF2240, also currently, receives significant research attention. Apart from its high cytotoxicity against tumour cells, this strain also provided fundamental insight into NDV-mediated apoptosis mechanism which involves Bax protein recruitment as well as death receptor engagement. Studies on its ability to selectively induce apoptosis in tumour cells also resulted in a proposed p38 MAPK/NF-κB/IκBα pathway. The immunogenicity of AF2240 was also investigated through PBMC stimulation and macrophage infection. In addition, the enhanced oncolytic ability of this strain under hypoxic condition signifies its dynamic tumour tropism. This review is aimed to introduce and discuss the aforementioned details of the oncolytic AF2240 strain along with its current challenges which outlines the future research direction of this virus.

Plasmodium yoelii infection inhibits murine leukaemia WEHI-3 cell proliferation in vivo by promoting immune responses

Background

Leukaemia is a malignant leukocyte disorder with a high fatality rate, and current treatments for this disease are unsatisfactory. Therefore, new therapeutic strategies for leukaemia must be developed. Malaria parasite infection has been shown to be effective at combating certain neoplasms in animal experiments. This study is to demonstrate the anti-leukaemia activity of malaria parasite Plasmodium yoelii (P. yoelii) infection,.

Methods

In this study, the proportion of CD3, CD19, CD11b and Mac-3 cells was analysed by flow cytometry; the levels of IFN-γ and TNF-α in individual serum samples were measured by enzyme-linked immunosorbent assay, and the phagocytic activity of macrophages and natural killer (NK) cell activity were measured by flow cytometry.

Results

We found that P. yoelii infection significantly attenuated the growth of WEHI-3 cells in mice. In addition, tumor cell infiltration into the murine liver and spleen was markedly reduced. We also demonstrated that malaria parasite infection elicited anti-leukaemia activity by promoting immune responses, including increasing the surface markers of T cells (CD3) and B cells (CD19); decreasing the surface markers of monocytes (CD11b) and macrophages (Mac-3); inducing the secretion of IFN-γ and TNF-α; and increasing NK cell and macrophage activity.

Conclusions

Malaria parasite infection significantly decreases the number of myeloblasts and inhibits neoplasm proliferation in mice. In addition, malaria parasite infection inhibits murine leukaemia by promoting immune responses.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0433-4) contains supplementary material, which is available to authorized users.

Newcastle disease virus degrades HIF-1α through proteasomal pathways independent of VHL and p53

Newcastle disease virus (NDV) is a candidate agent for oncolytic virotherapy. Despite its potential, the exact mechanism of its oncolysis is still not known. Recently, we reported that NDV exhibited an increased oncolytic activity in hypoxic cancer cells. These types of cells negatively affect therapeutic outcome by overexpressing pro-survival genes under the control of the hypoxia-inducible factor (HIF). HIF-1 is a heterodimeric transcriptional factor consisting of a regulated α (HIF-1α) and a constitutive β subunit (HIF-1β). To investigate the effects of NDV infection on HIF-1α in cancer cells, the osteosarcoma (Saos-2), breast carcinoma (MCF-7), colon carcinoma (HCT116) and fibrosarcoma (HT1080) cell lines were used in the present study. Data obtained showed that a velogenic NDV infection diminished hypoxia-induced HIF-1α accumulation, leading to a decreased activation of its downstream target gene, carbonic anhydrase 9. This NDV-induced downregulation of HIF-1α occurred post-translationally and was partially abrogated by proteasomal inhibition. The process appeared to be independent of the tumour suppressor protein p53. These data revealed a correlation between NDV infection and HIF-1α downregulation, which highlights NDV as a promising agent to eliminate hypoxic cancer cells.

Antineoplastic activity of Newcastle disease virus strain D90 in oral squamous cell carcinoma

Newcastle disease virus (NDV), an avian paramyxovirus, possesses the ability to kill tumor cells. Here, we report the effects of NDV strain D90, which was isolated in China, against oral squamous cell carcinoma (OSCC) cells. In this study, we showed that the cell death induced by D90 was apoptotic. Furthermore, the apoptosis induced by D90 was dependent on the mitochondrial pathway, and the death receptor pathway may be not involved. Bax and Bcl-2 also played a role in the apoptosis induced by D90. Lymph node metastasis is a serious problem for oral cancer; we therefore evaluated the impact of D90 on the migration and invasion of OSCC cells. NDV D90 affected microtubules and microfilaments to inhibit the motility of OSCC prior to apoptosis. The effects of D90 on the migration and invasion rates of OSCC cells were evaluated by migration and invasion assays. Subsequently, the changes in sp1, RECK, MMP-2, and MMP-9 induced by a low concentration of D90 were detected by western blot and gelatin zymography. D90 significantly inhibited the invasion and metastasis of OSCC cells by decreasing the expression of sp1 and increasing the expression of RECK to suppress the expression and activity of MMP-2 and MMP-9.

Inhibitory and apoptosis-inducing effects of Newcastle disease virus strain AF2240 on mammary carcinoma cell line

Breast cancer is the malignant tumour that developed from cells of the breast and is the first leading cause of cancer death among women worldwide. Surgery, radiotherapy, and chemotherapy are the available treatments for breast cancer, but these were reported to have side effects. Newcastle disease virus (NDV) known as Avian paramyxovirus type-1 (APMV1) belongs to the genus Avulavirus in a family Paramyxoviridae. NDV is shown to be a promising anticancer agent, killing tumour cells while sparing normal cells unharmed. In this study, the oncolytic and cytotoxic activities of NDV AF2240 strain were evaluated on MDA-MB-231, human mammary carcinoma cell line, using MTT assay, and its inhibitory effects were further studied using proliferation and migration assays. Morphological and apoptotic-inducing effects of NDV on MD-MB-231 cells were observed using phase contrast and fluorescence microscopes. Detection of DNA fragmentation was done following terminal deoxyribonucleotide transferase-mediated Br-dUTP nick end labeling staining (TUNEL) assay, which confirmed that the mode of death was through apoptosis and was quantified by flow cytometry. Furthermore, analysis of cellular DNA content demonstrated that the virus caused an increase in the sub-G1 phase (apoptotic peak) of the cell cycle. It appears that NDV AF2240 strain is a potent anticancer agent that induced apoptosis in time-dependent manner.

Thymoquinone inhibits murine leukemia WEHI-3 cells in vivo and in vitro

BACKGROUND

Thymoquinone is an active ingredient isolated from Nigella sativa (Black Seed). This study aimed to evaluate the in vitro and in vivo anti-leukemic effects of thymoquinone on WEHI-3 cells.

METHODOLOGY/PRINCIPAL FINDINGS

The cytotoxic effect of thymoquinone was assessed using an MTT assay, while the inhibitory effect of thymoquinone on murine WEHI-3 cell growth was due to the induction of apoptosis, as evidenced by chromatin condensation dye, Hoechst 33342 and acridine orange/propidium iodide fluorescent staining. In addition, Annexin V staining for early apoptosis was performed using flowcytometric analysis. Apoptosis was found to be associated with the cell cycle arrest at the S phase. Expression of Bax, Bcl2 and HSP 70 proteins were observed by western blotting. The effects of thymoquinone on BALB/c mice injected with WEHI-3 cells were indicated by the decrease in the body, spleen and liver weights of the animal, as compared to the control.

CONCLUSION

Thymoquinone promoted natural killer cell activities. This compound showed high toxicity against WEHI-3 cell line which was confirmed by an increase of the early apoptosis, followed by up-regulation of the anti-apoptotic protein, Bcl2, and down-regulation of the apoptotic protein, Bax. On the other hand, high reduction of the spleen and liver weight, and significant histopathology study of spleen and liver confirmed that thymoquinone inhibited WEHI-3 growth in the BALB/c mice. Results from this study highlight the potential of thymoquinone to be developed as an anti-leukemic agent.

Acute toxicity study of zerumbone-loaded nanostructured lipid carrier on BALB/c mice model

Zerumbone- (ZER-) loaded nanostructure lipid carrier (NLC) (ZER-NLC) prepared for its antileukemia effect in vitro was evaluated for its toxicological effects by observing changes in the liver, kidney, spleen, lung, heart, and brain tissues, serum biochemical parameters, total haemogram, and bone marrow stem cells. The acute toxicity study for ZER-NLC was conducted by orally treating BALB/c mice with a single dose with either water, olive oil, ZER, NLC, or ZER-NLC for 14 days. The animals were observed for clinical and behavioral abnormalities, toxicological symptoms, feed consumption, and gross appearance. The liver, kidney, heart, lung, spleen, and brain tissues were assessed histologically. Total haemogram was counted by hemocytometry and microhematocrit reader. Bone marrow examination in terms of cellular morphology was done by Wright staining with bone marrow smear. Furthermore, serum biochemical parameters were determined spectrophotometrically. Grossly all treated mice, their investigated tissues, serum biochemical parameters, total haemogram, and bone marrow were normal. At oral doses of 100 and 200 mg/kg ZER-NLC there was no sign of toxicity or mortality in BALB/c mice. This study suggests that the 50% lethal dose (LD₅₀) of ZER-NLC is higher than 200 mg/kg, thus, safe by oral administration.

Gene expression profiling in PC12 cells infected with an oncolytic Newcastle disease virus strain

Although the oncolytic potential of natural, non-engineered Newcastle disease virus (NDV) isolates are well-known, cellular mechanisms determining NDV sensitivity of tumor cells are poorly understood. The aim of the present study was to look for gene expression changes in PC12 pheochromocytoma cells infected with an attenuated NDV strain that may be related to NDV susceptibility. PC12 cells were infected with the NDV strain MTH-68/H for 12h at a titer corresponding to the IC₅₀ value. Total cytoplasmic RNA samples isolated from control and MTH-68/H-infected cells were analyzed using a rat specific Affymetrix exon chip. Genes with at least 2-fold increase or decrease in their expression were identified. MTH-68/H-induced gene expression changes of 9 genes were validated using quantitative reverse transcriptase PCR. A total of 729 genes were up- and 612 genes were down-regulated in PC12 cells infected with MTH-68/H. Using the DAVID functional annotation clustering tool, the up- and down-regulated genes can be categorized into 176 and 146 overlapping functional gene clusters, respectively. Gene expression changes affecting the most important signaling mechanisms (Toll-like receptor signaling, RIG-I-like receptor signaling, interferon signaling, interferon effector pathways, apoptosis pathways, endoplasmic reticulum stress pathways, cell cycle regulation) are analyzed and discussed in detail in this paper. NDV-induced gene expression changes described in this paper affect several regulatory mechanisms and dozens of putative key proteins that may determine the NDV susceptibility of various tumors. Further characterization of these proteins may identify susceptibility markers to predict the chances of virotherapeutic treatment of human tumors.

Newcastle disease virus Malaysian strain AF2240 induces apoptosis in MCF-7 human breast carcinoma cells at an early stage of the virus life cycle

Newcastle disease virus (NDV) AF2240 Malaysian strain is a very virulent avian virus. NDV strain AF2240 was previously demonstrated to induce apoptosis in human breast carcinoma MCF-7 cells. However, at which stage of the NDV life cycle apoptosis is induced and whether NDV replication and protein synthesis are involved in apoptosis induction have yet to be determined. In the present study, we investigated the time course of NDV strain AF2240 nucleoprotein (NP) gene expression and the early apoptotic signs in the form of activation of caspase-8 and mitochondrial transition pore opening. In addition, the induction of apoptosis by both ultraviolet-inactivated and cycloheximide-treated NDV-infected MCF-7 cells were examined. Our findings showed that NDV strain AF2240 induced apoptosis at 1 h post-infection (pi) through activation of mitochondrial transition pore opening and at 2 h through activation of caspase-8, while the NP gene was expressed at 6 h pi. The induced apoptosis was independent of both virus replication and protein synthesis. In conclusion, NDV strain AF2240 induces apoptosis at an early stage of its life cycle, possibly during virus binding or fusion with the cell membrane. The mitochondrial-related pathway may be the central activator in NDV strain AF2240-induced apoptosis.

Cytotoxicity, Antiproliferative Effects, and Apoptosis Induction of Methanolic Extract of Cynometra cauliflora Linn. Whole Fruit on Human Promyelocytic Leukemia HL-60 Cells

Methanolic extract of Cynometra cauliflora whole fruit was assayed for cytotoxicity against the human promyelocytic leukemia HL-60 and the normal mouse fibroblast NIH/3T3 cell lines by using the MTT assay. The CD(50) of the extract for 72 hours was 0.9 μg/mL whereas the value for the cytotoxic drug vincristine was 0.2 μg/mL. The viability of the NIH/3T3 cells was at 80.0% when treated at 15.0 μg/mL. The extract inhibited HL-60 cell proliferation with dose dependence. AO/PI staining of HL-60 cells treated with the extract revealed that majority of cells were in the apoptotic cell death mode. Flow cytometry analysis of HL-60 cells treated at CD(50) of the extract showed that the early apoptotic cells were 31.0, 26.3 and 19.9% at 24, 48, and 72 hours treatment, respectively. The percentage of late apoptotic cells was increased from 62.0 at 24 hours to 64.1 and 70.2 at 48 and 72 hours, respectively. Meanwhile, percent of necrotic cells were 4.9, 6.6, and 8.5 at 24, 48, and 72 hours, respectively. This study has shown that the methanolic extract of C. cauliflora whole fruit was cytotoxic towards HL-60 cells and induced the cells into apoptotic cell death mode, but less cytotoxic towards NIH/3T3 cells.