[Construction, screening and immunogenicity of the recombinant poxvirus vaccine rVTTδTK-RBD against SARS-CoV-2].

Objective To construct a recombinant poxvirus vector vaccine, rVTTδTK-RBD, and to evaluate its safety and immunogenicity. Methods The receptor-binding domain (RBD) gene was synthesized with reference to the gene sequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was inserted into the polyclonal site of the self-constructed recombinant plasmid pSTKE, to construct the recombinant poxvirus shuttle vector pSTKE-RBD. This was then transfected into BHK-21 cells pre-infected with the vaccinia virus Tiantan strain (VTT). The recombinant poxvirus rVTTδTK-RBD was successfully obtained after several rounds of fluorescence phage screening. The effect of rVTTδTK-RBD on the body mass of BALB/c mice was detected after immunizing mice by intra-nasal vaccination. The levels of specific and neutralizing antibodies produced by rVTTδTK-RBD on BALB/c mice were analyzed after immunizing mice intramuscularly. The effect of rVTTδTK-RBD on T cell subsets in BALB/c mice was detected by flow cytometry. Results Through homologous recombination, enhanced green fluorescent protein (EGFP) screening marker, and multiple rounds of fluorescent phosphorescence phage screening, a recombinant poxvirus rVTTδTK-RBD, expressing RBD with deletions in the thymidine kinase (TK) gene, was successfully obtained, which was validated by PCR. The in vivo experiments on BALB/c mice showed that rVTTδTK-RBD was highly immunogenic against SARS-CoV-2 and significantly reduced toxicity to the body compared to the parental strain VTT. Conclusion The recombinant poxvirus vaccine rVTTδTK-RBD against SARS-CoV-2 is successfully constructed and obtained, with its safety and immunogenicity confirmed through various experiments.

Peimisine ameliorates DSS-induced colitis by suppressing Jak-Stat activation and alleviating gut microbiota dysbiosis in mice.

OBJECTIVES: Inflammatory cytokine secretion and gut microbiota dysbiosis play crucial roles in ulcerative colitis. In this research, the protective effects of peimisine on colitis mice were investigated. METHODS: The protective effects were evaluated by the disease activity index, colonic length, hematoxylin-eosin, and AB/PAS Staining. The protective mechanisms were analyzed by ELISA, Western-blot, immunohistochemistry staining, immunofluorescence staining, and 16S rRNA gene analysis. KEY FINDINGS: The results showed that peimisine treatment could reduce the disease activity index, prevent colonic shortening, and alleviate colon tissue damage. Peimisine treatment also decreased the levels of MCP-1, IL-1ß, IL-6, IFN-γ, TNF-α and affected macrophage polarization and Th17/Treg cell balance by downregulating the expression of jak1/2, p-jak1/2, stat1/3, and p-stat1/3. Moreover, peimisine treatment significantly increased the abundances of beneficial microbes (e.g. Ruminococcaceae UCG-014 and Lachnospiraceae_NK4A136_group) and decreased the abundances of harmful microbes (e.g. Bacteroides and Escherichia). CONCLUSIONS: Peimisine can ameliorate colitis by inhibiting Jak-Stat signaling pathway, reversing gut microbiota alterations, suppressing macrophage M1 polarization, maintaining the Th17/Treg cell balance, and reducing sustained inflammatory cytokines-related inflammatory injury.

Human adenovirus type 7 subunit vaccine induces dendritic cell maturation through the TLR4/NF-κB pathway is highly immunogenic.

Introduction: Human adenovirus type 7 (HAdv-7) infection is the main cause of upper respiratory tract infection, bronchitis and pneumonia in children. At present, there are no anti- adenovirus drugs or preventive vaccines in the market. Therefore, it is necessary to develop a safe and effective anti-adenovirus type 7 vaccine. Methods: In this study, In this study, we used the baculovirus-insect cell expression system to design a recombinant subunit vaccine expressing adenovirus type 7 hexon protein (rBV-hexon) to induce high-level humoral and cellular immune responses. To evaluate the effectiveness of the vaccine, we first detected the expression of molecular markers on the surface of antigen presenting cells and the secretion of proinflammatory cytokines in vitro. We then measured the levels of neutralizing antibodies and T cell activation in vivo. Results: The results showed that the rBV-hexon recombinant subunit vaccine could promote DC maturation and improve its antigen uptake capability, including the TLR4/NF-κB pathway which upregulated the expression of MHCI, CD80, CD86 and cytokines. The vaccine also triggered a strong neutralizing antibody and cellular immune response, and activated T lymphocytes. Discussion: Therefore, the recombinant subunit vaccine rBV-hexon promoted promotes humoral and cellular immune responses, thereby has the potential to become a vaccine against HAdv-7.

Neobavaisoflavone induces pyroptosis of liver cancer cells via Tom20 sensing the activated ROS signal.

BACKGROUND: Neobavaisoflavone (NBIF), a natural active ingredient isolated from Psoralea, possesses anti-inflammatory, anti-cancer, and antioxidant properties; however, the anti-tumor mechanism of NBIF has not been thoroughly investigated, and the inhibitory effect and inhibitory pathway of NBIF on liver cancer are still unknown. PURPOSE: Our study aimed to explore the effects of NBIF on hepatocellular carcinoma and its potential mechanisms. METHODS: First, we detected the inhibition of NBIF on HCC cells by the CCK8 assay and then observed the morphological changes of the cells under the microscope. Besides, we analyzed the changes in the pyroptosis level of NBIF when inhibiting the cells through flow cytometry, immunofluorescence, and a western blot assay. Finally, we used a mouse tumor-bearing model to explore the effects of NBIF in vivo on HCCLM3 cells. RESULTS: NBIF-treated HCC cells exhibited specific features of pyroptosis. Analysis of pyroptosis-related protein levels revealed that NBIF primarily induced pyroptosis in HCC cells via the caspase-3-GSDME signaling pathway. Then, we demonstrated that NBIF impacted the protein expression of Tom20 by producing ROS in HCC cells, hence promoting the recruitment of Bax to mitochondria, activating caspase-3, cutting GSDME, and triggering pyroptosis. CONCLUSIONS: By activating ROS, NBIF was able to trigger pyroptosis in HCC cells, providing an experimental basis for the future study of new treatments for liver cancer.

Inhibitory Effects of Esculetin on Liver Cancer Through Triggering NCOA4 Pathway-Mediation Ferritinophagy in vivo and in vitro.

Objective: To explore the effects of Esculetin on liver cancer and explore potential mechanisms of Esculetin-inducing cells death. Methods: Esculetin's effects on the proliferation, migration and apoptosis of HUH7 and HCCLM3 cells were detected by using CCK8, crystal violet staining, wound healing, TranswellTM and Annexin V-FITC/PI. Flow cytometry, fluorescence staining, Western blot, T-AOC, DPPH radical scavenging assay, hydroxyl radical's inhibitory capability and GSH test were used to examine the esculetin's effects on the ROS level, the oxidation-related substances and proteins' expression in hepatoma cells. In vivo experiment was performed by xenograft model. Ferrostatin-1 was used to determine the death way of hepatoma cells induced by esculetin. Live cell probe, Western blot, Fe2+ content, MDA, HE staining, Prussian blue staining and immunohistochemistry were used to examine the ferritinophagy-related phenomenon induced by esculetin in hepatoma cells. The relationship between esculetin and NCOA4-mediated ferritinophagy was confirmed through gene silence and overexpression, immunofluorescence staining and Western blot. Results: Esculetin suppressed the proliferation, migration and apoptosis of HUH7 and HCCLM3 cells significantly, influenced the oxidative stress level, altered the autophagy and iron metabolism levels in cells, and produced a ferritinophagy-related phenomena. Esculetin increased the levels of cellular lipid peroxidation and reactive oxygen species. In vivo, esculetin could decrease tumour volume, promote LC3 and NCOA4 expressions, suppresse hydroxyl radical's inhibiting capacity and GSH, increase Fe2+ and MDA levels, decrease antioxidant proteins expression in tumour tissue. In addition, Esculetin could also increase the iron deposition of tumour tissues, promote ferritinophagy, and induce tumours' ferroptosis. Conclusion: Esculetin has an inhibitory effect on liver cancer in vivo and in vitro through triggering NCOA4 pathway-mediation ferritinophagy.

Human adenovirus type 7 virus-like particle vaccine induces Dendritic cell maturation through the TLR4/NF-κB pathway and is highly immunogenic.

Human adenovirus type 7 (HAdv-7) infection is the main cause of upper respiratory tract infection, bronchitis and pneumonia in children. At present, there are no anti-adenovirus drugs or preventive vaccines in the market. Therefore, it is necessary to develop a safe and effective anti-adenovirus type 7 vaccine. In this study, we designed a virus-like particle vaccine expressing the epitopes of hexon and penton of adenovirus type 7 with hepatitis B core protein (HBc) as the vector to induce high-level humoral and cellular immune responses. To evaluate the effectiveness of the vaccine, we first detected the expression of molecular markers on the surface of antigen presenting cells and the secretion of proinflammatory cytokines in vitro. We then measured the levels of neutralizing antibodies and T cell activation in vivo. The results showed that the HAdv-7 virus-like particles (VLPs) recombinant subunit vaccine could activate the innate immune response, including the TLR4/NF-κB pathway which upregulated the expression of MHC II, CD80, CD86, CD40 and cytokines. The vaccine also triggered a strong neutralizing antibody and cellular immune response and activated T lymphocytes. Therefore, the HAdv-7 VLPs promoted humoral and cellular immune responses, thereby potentially enhancing protection against HAdv-7 infection.

Apoptotic and autophagic cell death induced in cervical cancer cells by a dual specific oncolytic adenovirus.

OBJECTIVE: Oncolytic adenoviruses are capable of exerting anticancer effects via a variety of mechanisms, including apoptosis and autophagy. In the present study, the dual-specific antitumor oncolytic adenovirus, Ad-Apoptin-hTERT-E1a (ATV), was used to infect cervical cancer cell lines to test its antitumor effects. METHODS: To explore the use of apoptin in tumor gene therapy, a recombinant adenovirus ATV expressing the apoptin protein was assessed to determine its lethal and growth-inhibitory effects on human cervical cancer cell line (HeLa) cells in vitro . Nonapoptotic autophagy of HeLa cells infected with ATV was assessed by examining the cell morphology, development of acidic vesicular organelles and the conversion of microtubule-associated protein 1 light chain 3 (LC3) from its cytoplasmic to autophagosomal membrane form. Using gene silencing (knockdown of LC3 and Belin-1), autophagy-associated molecules (e.g. ATG5, ATG12 and ULK1) were monitored by real-time PCR and western blot. RESULTS: A series of experiments demonstrated that ATV could significantly induce apoptosis and autophagy in cervical cancer cells, and provided evidence that ATV not only induced apoptosis but also autophagy and ATG5, ATG12 and ULK1 related pathways were not entirely dependent on LC3 and Beclin-1. CONCLUSION: These results indicate that ATV may have a potential application in tumor gene therapy.

Apoptin causes apoptosis in HepG-2 cells via Ca2+ imbalance and activation of the mitochondrial apoptotic pathway.

BACKGROUND: Apoptin is derived from the chicken anemia virus and exhibits specific cytotoxic effects against tumor cells. Herein, we found that Apoptin induced a strong and lasting endoplasmic reticulum (ER) stress response, Ca2+ imbalance, and triggered the mitochondrial apoptotic pathway. The aim of this study was to explore the mechanisms by which Apoptin exhibited anti-tumor effects in HepG-2 cells. METHODS: The intracellular levels of calcium (Ca2+ ) were induced by ER stress and determined by electron microscopy, flow cytometry, and fluorescence staining. The mitochondrial injury was determined by mitochondrial membrane potential and electron microscopy. Western blotting was used to investigate the levels of key proteins in ER stress and the apoptotic pathway in mitochondria. The relationship between Ca2+ levels and apoptosis in Apoptin-treated cells was analyzed using a Ca2+ chelator (BAPTA-AM), flow cytometry, and fluorescence staining. We also investigated the in vivo effects of Ca2+ imbalance on the mitochondrial apoptotic pathway using tumor tissues xenografted on nude mice. RESULTS: This study showed that Apoptin induced a strong and long- lasting ER stress and injury, which subsequently led to an imbalance of cellular Ca2+ levels, a reduction in the mitochondrial membrane potential, a significant extent image in the mitochondrial structure, and an increase in the expression levels of Smac/Diablo and Cyto-C. CONCLUSIONS: In summary, Apoptin induced apoptosis in HepG-2 cells via Ca2+ imbalance and activation of the mitochondrial apoptotic pathway. This study provided a new direction for antitumor research in Apoptin.

Apoptin mediates mitophagy and endogenous apoptosis by regulating the level of ROS in hepatocellular carcinoma.

BACKGROUND: Apoptin, as a tumor-specific pro-apoptotic protein, plays an important anti-tumoral role, but its mechanism of autophagy activation and the interaction between autophagy and apoptosis have not been accurately elucidated. Here, we studied the mechanism of apoptin-induced apoptosis and autophagy and the interaction between two processes. METHODS: Using crystal violet staining and the CCK-8 assay, we analyzed the effect of apoptin in the inhibition of liver cancer cells in vitro and analyzed the effect of inhibiting liver cancer in vivo by establishing a nude mouse tumor model. Flow cytometry and fluorescence staining were used to analyze the main types of apoptin-induced apoptosis and autophagy. Subsequently, the relationship between the two events was also analyzed. Flow cytometry was used to analyze the effect of ROS on apoptin-mediated apoptosis and autophagy mediated by apoptin. The effect of ROS on two phenomena was analyzed. Finally, the role of key genes involved in autophagy was analyzed using gene silencing. RESULTS: The results showed that apoptin can significantly increase the apoptosis and autophagy of liver cancer cells, and that apoptin can cause mitophagy through the increase in the expression of NIX protein. Apoptin can also significantly increase the level of cellular ROS, involved in apoptin-mediated autophagy and apoptosis of liver cancer cells. The change of ROS may be a key factor causing apoptosis and autophagy. CONCLUSION: The above results indicate that the increase in ROS levels after apoptin treatment of liver cancer cells leads to the loss of mitochondrial transmembrane potential, resulting in endogenous apoptosis and mitophagy through the recruitment of NIX. Therefore, ROS may be a key factor connecting endogenous apoptosis and autophagy induced by apoptin in liver cancer cells. Video abstract.

A comparative study of the ability of recombinant oncolytic adenovirus, doxorubicin and tamoxifen to inhibit the proliferation of breast cancer cells.

In this study, we compared the inhibitory effects of recombinant oncolytic adenovirus (Ad-apoptin-hTERTp-E1a, Ad-VT) with that of doxorubicin (DOX), a first-line chemotherapy drug, and tamoxifen (TAM), an endocrine therapy drug, on the proliferation of breast cancer cells. We found that Ad-VT could effectively inhibit the proliferation of breast cancer cells (p < 0.01); the inhibition rate of Ad-VT on normal mammary epithelial MCF-10A cells was less than 20%. DOX can effectively inhibit the proliferation of breast cancer cells and also has a strong inhibitory effect on MCF-10A cells (p < 0.01). TAM also has a strong inhibitory effect on breast cancer cells, among which the oestrogen-dependent MCF-7 cell inhibition was stronger (p < 0.01), At higher concentrations, TAM also had a high rate of inhibition (>70%) on the proliferation of MCF-10A cells. We also found that both recombinant adenovirus and both drugs could successfully induce tumour cell apoptosis. Further Western blot results showed that the recombinant adenovirus killed breast cancer cells through the endogenous apoptotic pathway. Analysis of the nude mouse subcutaneous breast cancer model showed that Ad-VT significantly inhibited tumour growth (the luminescence rate of cancer cells was reduced by more than 90%) and improved the survival rate of tumour-bearing mice (p < 0.01). Compared with DOX and TAM, Ad-VT has a significant inhibitory effect on breast cancer cells, but almost no inhibitory effect on normal breast epithelial cells, and this inhibitory effect is mainly through the endogenous apoptotic pathway. These results indicate that Ad-VT has significant potential as a drug for the treatment of breast cancer.

Recombinant Oncolytic Adenovirus Combined with Cyclophosphamide Induces Synergy in the Treatment of Breast Cancer in vitro and in vivo.

Purpose: Oncolytic virus therapy has gradually become an integral approach in cancer treatment. We explored the therapeutic effects of the combination of a dual cancer-selective anti-tumor recombinant adenovirus (Ad-Apoptin-hTERTp-E1a) and cyclophosphamide on breast cancer cells. Methods: The inhibition of MCF-7 and MDA-MB-231 breast cancer cells by Ad-Apoptin-hTERTp-E1a (Ad-VT), cyclophosphamide, and Ad-VT + Cyclophosphamide was investigated using the CCK-8 assay. The combination index (CI) was calculated using CalcuSyn software to determine the best combination based on the inhibition rates of the different treatment combinations. The CCK-8 assay and crystal violet staining were used to detect the cytotoxicity of the combined Ad-VT and cyclophosphamide in breast cancer cells and breast epithelial cells. Subsequently, Hoechst staining, annexin V flow cytometry, and JC-1 staining were used to analyze the inhibitory pathway of Ad-VT plus cyclophosphamide on breast cancer cells. Cell migration and invasion of breast cancer cells were assessed using the cell-scratch and Transwell assays. The anti-tumor effects of different treatment groups in a tumor-bearing nude mouse model also were analyzed. Results: The treatment combination of Ad-VT (40 MOI) and cyclophosphamide (400 µM) significantly inhibited MCF-7 and MDA-MB-231 cells and reduced the toxicity of cyclophosphamide in normal cells. Ad-VT primarily induced breast cancer cell apoptosis through the endogenous apoptotic pathway. Apoptosis was significantly increased after treatment with Ad-VT plus cyclophosphamide. The combination significantly inhibited the migration and invasion of MCF-7 and MDA-MB-231 cells. The in vivo experiments demonstrated that exposure to Ad-VT plus cyclophosphamide significantly inhibited tumor growth and extended the survival time of the nude mice. Conclusion: Ad-VT plus cyclophosphamide reduced toxicity and exhibited increased efficacy in treating breast cancer cells.

Caryophyllene Oxide Induces Ferritinophagy by Regulating the NCOA4/FTH1/LC3 Pathway in Hepatocellular Carcinoma.

Ferritinophagy is associated with tumor occurrence, development, and therapy effects. Ferritinophagy and ferroptosis are regulated by iron metabolism and are closely connected. LC3 protein is a key protein in autophagy. Following the binding of NCOA4 to FTH1, it links to LC3Ⅱ in lysosomes, a symbol of ferritinophagy. A ferritinophagy's inducer is likely to open new avenues for anticancer medication research and development. In this study, we discovered that caryophyllene oxide has a substantial inhibitory effect on HCCLM3 and HUH7 cells, by regulating the level of cellular oxidative stress, and the levels of autophagy and iron metabolism in HCCLM3 and HUH7 cells, leading to a ferritinophagy-related phenomenon. Furthermore, the results of T-AOC, DPPH free radical scavenging rate, and hydroxyl radical inhibition indicated that caryophyllene oxide can inhibit cell anti-oxidation. The examination of the ferritinophagy-related process revealed that caryophyllene oxide promotes the production and accumulation of intracellular reactive oxygen species and lipid peroxidation. NCOA4, FTH1, and LC3Ⅱ were found to be targeted regulators of caryophyllene oxide. Caryophyllene oxide regulated NCOA4, LC3 Ⅱ, and FTH1 to promote ferritinophagy. In vivo, we discovered that caryophyllene oxide can lower tumor volume, significantly improve NCOA4 and LC3 protein levels in tumor tissue, and raise Fe2+ and malondialdehyde levels in serum. The compound can also reduce NRF2, GPX4, HO-1, and FTH1 expression levels. The reduction in the expression levels of NRF2, GPX4, HO-1, and FTH1 by caryophyllene oxide also inhibited GSH and hydroxyl radical's inhibitory capacities in serum, and promoted iron deposition in tumor tissue resulting in the inhibition of tumor growth. In summary, our study revealed that caryophyllene oxide mostly kills liver cancer cells through ferritinophagy-mediated ferroptosis mechanisms. In conclusion, caryophyllene oxide may be used as a ferritinophagy activator in the field of antitumor drug research and development.

Apoptin induces pyroptosis of colorectal cancer cells via the GSDME-dependent pathway.

Apoptin is a small molecular weight protein encoded by the VP3 gene of chicken anemia virus (CAV). It can induce apoptosis of tumor cells and play anti-tumorigenic functions. In this study, we identified a time-dependent inhibitory role of apoptin on the viability of HCT116 cells. We also demonstrated that apoptin induces pyroptosis through cleaved caspase 3, and with a concomitant cleavage of gasdermin E (GSDME) rather than GSDMD. GSDME knockdown switched the apoptin-induced cell death from pyroptosis to apoptosis in vitro. Furthermore, we demonstrated that the effect of apoptin on GSDME-dependent pyroptosis could be mitigated by caspase-3 and caspase-9 siRNA knockdown. Additionally, apoptin enhanced the intracellular reactive oxygen species (ROS), causing aggregation of the mitochondrial membrane protein Tom20. Moreover, bax and cytochrome c were released to the activating caspase-9, eventually triggering pyroptosis. Therefore, GSDME mediates the apoptin-induced pyroptosis through the mitochondrial apoptotic pathway. Finally, using nude mice xenografted with HCT116 cells, we found that apoptin induces pyroptosis and significantly inhibits tumor growth. Based on this mechanism, apoptin may provide a new strategy for colorectal cancer therapy.

In vivo and in vitro inhibition of SCLC by combining dual cancer-specific recombinant adenovirus with Etoposide.

PURPOSE: Oncolytic virotherapy is emerging as an important modality in cancer treatment. In a previous study, we designed and constructed Ad-Apoptin-hTERTp-E1a (Ad-VT), a dual cancer-selective anti-tumor recombinant adenovirus. METHODS: To explore the therapeutic effect of recombinant adenovirus Ad-VT together with Etoposide on small cell lung cancer, the ability of Ad-VT alone, Etoposide alone, and a combination of Ad-VT + Etoposide to inhibit proliferation of NCI-H446 and BEAS-2B cells was investigated using the WST-1 method. According to the inhibitory action of different combinations, a combination index (CI) was estimated by CalcuSyn software to select the best combination. The inhibitory effect of Ad-VT combined with Etoposide on NCI-H446 and BEAS-2B cells was detected by crystal violet staining and the CFST method. Hoechst, Annexin V and JC-1 staining were used to explore the inhibitory pathway of Ad-VT combined with Etoposide on NCI-H446 cells. The migratory and invasive abilities of treated NCI-H446 cells were assessed by Transwell and BioCat methods. Tumor volume, body weight and survival rate were measured to analyze the anti-tumor and toxic effects of different treatments in tumor-bearing mice. RESULTS: Ad-VT (20 MOI) combined with Etoposide (400 nM) significantly inhibited NCI-H446 cell proliferation with reduced toxicity of Etoposide to normal cells. Ad-VT induced apoptosis of NCI-H446 cells mainly through the mitochondrial apoptosis pathway, an effect significantly increased by the combined treatment. Ad-VT together with Etoposide significantly inhibited migration and invasion of NCI-H446 cells, inhibited tumor growth in vivo and prolonged the survival of tumor-bearing mice. CONCLUSIONS: The above results indicate that when combined with Etoposide, Ad-VT may have an important role in synergistically inhibiting tumors.

Ad-Apoptin-hTERTp-E1a Regulates Autophagy Through the AMPK-mTOR-eIF4F Signaling Axis to Reduce Drug Resistance of MCF-7/ADR Cells.

Ad-VT (Ad-Apoptin-hTERTp-E1a) is a type of oncolytic adenovirus with dual specific tumor cell death ability. It can effectively induce cell death of breast cancer cells and has better effect when used in combination with chemotherapy drugs. However, it has not been reported whether Ad-VT reduces the resistance of breast cancer cells to chemotherapy drugs. The purpose of this study is to investigate the effect of Ad-VT on drug resistance of Adriamycin-resistant breast cancer cells. For this, the effects of different doses of Ad-VT on the resistance of breast cancer cells to Adriamycin were analyzed using qualitative and quantitative experiments in vitro and in vivo. The Ad-VT can reduce the resistance of MCF-7/ADR to adriamycin, which is caused by the reduction of MRP1 protein level in MCF-7/ADR cells after treatment with Ad-VT, and MRP1 can be interfered with by autophagy inhibitors. Subsequently, the upstream signal of autophagy was analyzed and it was found that Ad-VT reduced the resistance of cells to doxorubicin by reducing the level of mTOR, and then the analysis of the upstream and downstream proteins of mTOR found that Ad-VT increased the sensitivity of MCF-7/ADR cells to adriamycin by activating AMPK-mTOR-eIF4F signaling axis. Ad-VT can not only significantly induce cell death in MCF-7/ADR cells, but also improved their sensitivity to Adriamycin. Therefore, the combination of Ad-VT and chemotherapy drugs may become a new strategy for the treatment of breast cancer in overcoming Adriamycin resistance.

Suppression effect of a dual cancer-specific oncolytic adenovirus on luciferase-labeled human melanoma cells in vitro and in vivo.

BACKGROUND: To explore the suppressive effect of Apoptin-loaded oncolytic adenovirus (Ad-VT) on luciferase-labeled human melanoma cells in vitro and in vivo. METHODS: The stable luciferase-expressing human melanoma cells A375-luc or M14-luc were obtained by transfecting the plasmid pGL4.51 and selection with G418, followed by luciferase activity, genetic stability and bioluminescence intensity assays. In vitro, the inhibitory effects of Ad-VT on A375-luc or M14-luc were evaluated using the MTS cell proliferation, FITC-Annexin V apoptosis detection, transwell migration, Matrigel invasion and scratch assays. The inhibition pathway in Ad-VT-infected A375-luc and M14-luc cells were analyzed by JC-1 staining and Western-blot detection of mitochondrial apoptosis-related proteins. In vivo, the suppressive effects of Ad-VT on A375-luc or M14-luc were assessed by living imaging technology, tumor volume, bioluminescence intensity, survival curves and immunohistochemical analysis of the tumors from the xenograft tumor model BALB/c nude mice. RESULTS: The growth and migration of A375-luc and M14-luc were significantly inhibited by Ad-VT in vitro. The evaluations of A375-luc and M14-luc tumor models in BALB/c nude mice were successfully performed using living imaging technology. Ad-VT had an anti-tumor effect by reducing tumor growth and increasing survival in vivo. Ad-VT significantly changed the mitochondrial membrane potential by triggering the the mitochondrial release of apoptosis-related proteins, AIF (apoptosis inducing factor), ARTS (Apoptosis-Related Proteins), and Cyto-c (cytochrome c) from the mitochondria. CONCLUSION: Ad-VT reduced the mitochondrial membrane potential in A375-luc or M14-luc cells and induced the mitochondrial release of AIF, ARTS and Cyto-C. Ad-VT induced apoptosis in A375-luc or M14-luc cells via the mitochondrial apoptotic pathway.

Effects of Apoptin-Induced Endoplasmic Reticulum Stress on Lipid Metabolism, Migration, and Invasion of HepG-2 Cells.

In this study, we investigated the effects of Apoptin-induced endoplasmic reticulum (ER) stress on lipid metabolism, migration and invasion of HepG-2 cells, and preliminarily explored the relationship between endoplasmic reticulum stress, lipid metabolism, migration, and invasion. The effects of Apoptin on ER function and structure in HepG-2 cells were determined by flow cytometry, fluorescence staining and western blotting by assessing the expression levels of ER stress related proteins. The effects of Apoptin on HepG-2 cells' lipid metabolism were determined by western blot analysis of the expression levels of triglyceride, cholesterol, and lipid metabolism related enzymes. The effects of Apoptin on HepG-2 cells' migration and invasion were studied using migration and invasion assays and by Western-blot analysis of the expression of proteins involved in migration and invasion. The in vivo effects of endoplasmic reticulum stress on lipid metabolism, migration and invasion of HepG-2 cells were also investigated by immunohistochemistry analysis of tumor tissues from HepG2 cells xenografted nude mice models. Both in vitro and in vivo experiments showed that Apoptin can cause a strong and lasting ER stress response, damage ER functional structure, significantly change the expression levels of lipid metabolism related enzymes and reduce the migration and invasion abilities of HepG-2 cells. Apoptin can also affect HepG-2 cells' lipid metabolism through endoplasmic reticulum stress and the abnormal expression of enzymes closely related to tumor migration and invasion. These results also showed that lipid metabolism may be one of the main inducements that reduce HepG-2 cells' migration and invasion abilities.

Autophagy promotes oncolysis of an adenovirus expressing apoptin in human bladder cancer models.

As a potential cancer therapy, we developed a recombinant adenovirus named Ad-VT, which was designed to express the apoptosis-inducing gene (apoptin) and selectively replicate in cancer cells via E1a manipulation. However, how it performs in bladder cancer remains unclear. We examined the antitumor efficacy of Ad-VT in bladder cancers using CCK-8 assays and xenograft models. Autophagy levels were evaluated by western blotting, MDC staining, and RFP-GFP-LC3 aggregates' analyses. Here, we report the selective replication and antitumor efficacy (viability inhibition and apoptosis induction) of Ad-VT in bladder cancer cells. Using xenograft tumor models, we demonstrate that its effects are tumor specific resulting in the inhibition of tumor growth and improvement of the survival of mice models. Most Importantly, Ad-VT induced a complete autophagy flux leading to autophagic cancer cell death through a signaling pathway involving AMPK, raptor and mTOR. Finally, we suggest that treatment combination of Ad-VT and rapamycin results in a synergistic improvement of tumor control and survival compared to monotherapy. This study suggests that Ad-VT can induce selective autophagic antitumor activities in bladder cancer through the AMPK-Raptor-mTOR pathway, which can be further improved by rapamycin.

Anti-tumour effects of a dual cancer-specific oncolytic adenovirus on Breast Cancer Stem cells.

Apoptin can specifically kill cancer cells but has no toxicity to normal cells. Human telomerase reverse transcriptase (hTERT) can act as a tumour-specific promoter by triggering the expression of certain genes in tumour cells. This study aims to investigate the inhibitory effects and to explore the inhibitory pathway of a dual cancer-specific recombinant adenovirus (Ad-apoptin-hTERTp-E1a, Ad-VT) on breast cancer stem cells. Breast cancer cell spheres were obtained from MCF-7 cells through serum-free suspension culture. The cell spheres were detected by flow cytometry for CD44+ CD24- cell subsets. The stemness of MCF-7-CSC cells was confirmed by in vivo tumorigenesis experiments. The inhibitory effect of the recombinant adenoviruses on MCF-7-CSC cells was evaluated by CCK-8 assay. In addition, the stemness of adenovirus-infected MCF-7-CSC cells was analysed by testing the presence of CD44+ CD24- cell subsets. The ability of the recombinant adenovirus to induce MCF-7-CSC cell apoptosis was detected by staining JC-1, TMRM and Annexin V. Our results showed that a significantly higher proportion of the CD44+ CD24- cell subsets was present in MCF-7-CSC cells with a significantly increased expression of stem cell marker proteins. The MCF-7-CSC cells, whlist exhibited a strong tumorigenic ability with a certain degree of stemness in mice, were shown to be strongly inhibited by recombinant adenovirus Ad-VT through cell apoptosis. In addition, Ad-VT was shown to exert a killing effect on BCSCs. These results provide a new theoretical basis for the future treatment of breast cancer.

Anti-tumor effect of a dual cancer-specific recombinant adenovirus on ovarian cancer cells.

BACKGROUND: Apoptin can specifically kill cancer cells but has no toxicity to normal cells. Human telomerase reverse transcriptase (hTERT) acts as a tumor-specific promoter, triggering certain genes to replicate or express only in tumor cells, conferring specific replication and killing abilities. This study aimed at investigating the anticancer potential of the recombinant adenovirus Ad-apoptin-hTERTp-E1a (Ad-VT) in ovarian cancer treatment. METHODS: Crystal Violet staining and WST-1 assays were used to analyze the inhibitory effect of Ad-VT on ovarian cancer SKOV3 and OVCAR-3 cells. Ad-VT-induced apoptosis of ovarian cancer cells, was detected using Hoechst, Annexin V-FITC/PI, JC-1 staining. Cell migration and invasion of ovarian cancer cells were detected using cell-scratch and Transwell assays. The pGL4.51 plasmid was used to transfect and to generate SKOV3-LUC cells, that stably express luciferase. The in vivo tumor inhibition effect of Ad-VT was subsequently confirmed using a tumor-bearing nude mouse model. RESULTS: Ad-VT had a strong apoptosis-inducing effect on SKOV3 and OVCAR-3 cells, that was mainly mediated through the mitochondrial apoptotic pathway. The Ad-VT could significantly increase the inhibition of ovarian cancer cell migration and invasion. The Ad-VT also can inhibit tumor growth and reduce toxicity in vivo. CONCLUSIONS: The recombinant adenovirus, comprising the apoptin protein and the hTERTp promoter, was able to inhibit the growth of ovarian cancer cells and promote their apoptosis.