Tianhao Weng

MicroRNA Expression Profiling of Pancreatic Cancer Cell Line L3.6p1 Following B7-H4 Knockdown

Background/Aims: Co-stimulating molecule B7-H4 regulates T cell-mediated immune responses, participates in tumor immune escape, and promotes the proliferation and metastasis of pancreatic cancer cells. However, the specific mechanisms are unclear. MicroRNAs (miRNAs) participated in the pathogenesis and progression of cancer. Methods: In this study, a microarray technique was used to screen B7-H4-related differentially expressed miRNAs in a pancreatic cancer cell line find those associated with pancreatic cancer. Using a miRCURYTM LNA Array approach, we compared the miRNA expression profiles of L3.6p1 pancreatic cancer cells transfected with B7-H4 siRNA for 72 h with those transfected with non-target siRNAs. Results: B7-H4 siRNA significantly up-regulated 57 miRNAs and down-regulated 14 miRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway analysis of predicted miRNA targets showed that these genes were mainly involved in protein binding, pathways in cancer, mitogen-activated protein kinase (MAPK) signaling pathway, and phosphatidylinositol 3-kinase-Akt (PI3K-Akt) signaling pathway. Conclusions: This is the first description of target genes of B7-H4, showing that miRNAs participate in the B7-H4 mediated regulation of oncogenicity and pathogenesis of pancreatic cancer. These results may help us better understand the role of B7-H4 in the progression of pancreatic cancer and its possible mechanisms. We also provide novel biomarkers for potential treatments of pancreatic cancer.

Prognostic significance of B7-H4 expression in matched primary pancreatic cancer and liver metastases

Liver metastasis development in pancreatic cancer patients is common and confers a poor prognosis. Clinical relevance of biomarker analysis in metastatic tissue is necessary. B7-H4 has an inhibitory effect on T cell mediated response and may be involved in tumor development. Although B7-H4 expression has been detected in pancreatic cancer, its expression in liver metastases from pancreatic cancer is still unknown. In this study, overall 43 pancreatic cancer liver metastases (with matched primaries in 15/43 cases) and 57 pancreatic cancer cases without liver metastases or other distant metastases were analyzed for their expression of B7-H4 by immunohistochemistry. Survival curves and log-rank tests were used to test the association of B7-H4 expression with survival. B7-H4 was highly expressed in 28 (65.1%) of the 43 liver metastases and 9 (60.0%) of the 15 matched primary tumors. The expression of B7-H4 in liver metastases was significantly higher than in the matched primary tumors (p < 0.05). Patients with high B7-H4 expression in their primary pancreatic cancer had higher risk of developing liver metastases (p < 0.05). In univariate analysis, B7-H4 expression was significantly associated with the risk of death (p < 0.05). And the multivariate analysis identified that B7-H4 was an independent prognostic indicator (p < 0.05). Our results revealed B7-H4 to be associated with poor prognosis in patients with pancreatic cancer liver metastasis. B7-H4 may promote pancreatic cancer metastasis and was promising to be a potential prognostic indicator of pancreatic cancer.

B7-H4 is a prognostic biomarker for poor survival in patients with pancreatic cancer ☆ ☆☆

B7-H4 belongs to the immune costimulatory B7 family and is thought to negatively regulate T-cell-mediated immunity, and may contribute an important role in tumor immune evasion. Although the expression of B7-H4 has been observed in human pancreatic cancer, the prognostic significance of this expression is poorly understood. This present study explored the prognostic value of B7-H4 in pancreatic cancer. Patients with pancreatic cancer and healthy controls were recruited at the Second Affiliated Hospital to Zhejiang University from January 2011 to December 2014. Expression of B7-H4 was assessed by immunohistochemistry. Immunohistochemical analysis indicated that B7-H4 was expressed in 100% (188/188) of the pancreatic cancer tumor tissue samples, while only in 68% (17/25) of normal pancreatic tissue samples. Furthermore, the expression levels of B7-H4 in pancreatic cancer patients were significantly higher than in controls (P<.01). A significant difference in B7-H4 expression was observed between patients with late tumor-node-metastasis (TNM) stage (III and IV) and early TNM stage (I and II) (P<.01). The expression of B7-H4 was associated with distant metastasis (P<.01) and differentiation (P<.01). In addition, B7-H4 expression (P<.01), distant metastasis (P<.01), TNM stage (P<.01), differentiation (P<.01) and chemotherapy treatment (P<.05) were indicators of poor overall survival time. Multivariate survival analysis indicated that B7-H4 expression, distant metastasis, and chemotherapy treatment (P<.05) were independent prognostic indicators of poor overall survival. In conclusion, B7-H4 is highly expressed in pancreatic cancer, and is an independent predictor of poor prognosis in patients with pancreatic cancer. B7-H4 may represent an immunotherapeutic target in pancreatic cancer.

Longevity of protective immune responses induced by a split influenza A (H7N9) vaccine mixed with MF59 adjuvant in BALB/c mice

The influenza virus is a serious threat to public health worldwide. A novel avian influenza A (H7N9) virus with a mortality rate of approximately 30% has been identified as an unusually dangerous virus for humans by the World Health Organization. Pathogenic H7N9 continue to represent a public health concern, and several candidate vaccines are currently in development. We generated candidate H7N9 vaccine strains using reverse genetics, consisting of hemagglutinin and neuraminidase genes derived from a human H7N9 virus and the remaining genes from the PR8 (A/PuertoRico/8/34 (H1N1)) virus. This H7N9 vaccine exhibited superior efficacy when combined with MF59 compared to other adjuvants. Immunized BALB/c mice were followed to determine the duration of the protective immune response. Antibody levels decreased to between one-half and one-eighth of the peak values four months after the final dose of the vaccine. Previously vaccinated mice received an A/Zhejiang/DTID-ZJU01/2013 H7N9 challenge six months post-vaccination, and all remained protected. We also verified that MF59 enhanced the HI, MN, and IgG antibody titers to influenza antigens. The humoral immune response and Th2 cytokine production following influenza challenge was potently induced in the animals that received the split vaccine. Therefore, the split H7N9 influenza vaccine with the MF59 adjuvant could effectively induce antibody production and protect mice from H7N9 virus challenge even after six months.

Preclinical Efficacy of Anti-RON Antibody–Drug Conjugate Zt/g4-MMAE for Targeted Therapy of Pancreatic Cancer Overexpressing RON Receptor Tyrosine Kinase

Aberrant expression of the RON receptor tyrosine kinase, a cell surface protein, is a pathogenic feature in pancreatic cancer, which renders it a drug target for targeted therapy. Nevertheless, development of therapeutics targeting RON for pancreatic cancer therapy is hampered due to the lack of full addiction by pancreatic cancer cells to RON signaling for growth and survival. Here we describe a novel strategy using anti-RON antibody-directed drug delivery in the form of an antibody-drug conjugate for inhibition and/or eradication of pancreatic cancers. Monoclonal antibody Zt/g4 specific to the RON Sema domain was selected as the drug carrier based on its ability to induce robust RON internalization. Conjugation of Zt/g4 with monomethyl auristatin E, designated as Zt/g4-MMAE, was achieved through a protease-sensitive dipeptide linker to reach a drug to antibody ratio of 3.29:1. Zt/g4-MMAE was stable in human plasma with a dissociation rate less than 4% within a 10 day period. In vitro, Zt/g4-MMAE rapidly induced RON internalization, resulting in cell cycle arrest followed by massive cell death. The maximal effect was seen in pancreatic cancer cells with more than 10 000 receptor molecules per cell. Zt/g4-MMAE also synergized in vitro with chemotherapeutics including gemcitabine, 5-fluorouracil, and oxaliplatin to further reduce PDAC cell viability. In vivo, Zt/g4-MMAE exerts a long-lasting activity, which not only inhibited but also eradicated pancreatic xenograft tumors. These finding indicate that Zt/g4-directed drug delivery is highly effective for eradicating pancreatic tumors. Thus, Zt/g4-MMAE is a novel biotherapeutic with potential for therapy of RON-expressing pancreatic malignancies.

The Protective Effects of the A/ZJU01/ PR8/2013 Split H7N9 Avian Influenza Vaccine Against Highly Pathogenic H7N9 in BALB/c Mice

Background/Aims: Since the first case of novel H7N9 infection was reported, China has experienced five epidemics of H7N9. During the fifth wave, a highly pathogenic H7N9 strain emerged. In order to assess whether the H7N9 vaccine based on A/Zhejiang/DTID-ZJU01/2013(H7N9) was effective in protecting against highly pathogenic H7N9, we conducted this study. Methods: Groups of mice were immunized twice by intraperitoneal injection with 500 µl of either split vaccine alone or MF59-adjuvanted vaccine. Serum was collected 2 weeks after the second vaccine booster. The hemagglutinin inhibition test was conducted on vaccine seed and highly pathogenic H7N9 to evaluate the neutralization of highly pathogenic H7N9. We also immunized mice and challenged them with highly pathogenic H7N9. Mice were observed for illness, weight loss, and death at 1 week and 2 weeks post-infection. Then, the mice were sacrificed and lungs were removed. Antibody responses were assessed and pathological changes in the lung tissue were evaluated. Results: The ability of serum to neutralize highly pathogenic H7N9 was reduced. In mice, highly pathogenic H7N9 was more virulent than A/Zhejiang/DTID-ZJU01/2013(H7N9). After challenge with highly pathogenic H7N9, all mice died while mice challenged with A/Zhejiang/DTID-ZJU01/2013(H7N9) all recovered. The A/ZJU01/PR8/2013 split H7N9 avian influenza vaccine was able to protect against infection with highly pathogenic H7N9 in mice, with or without MF59. Moreover, H7N9 vaccine adjuvanted with MF59 produced high antibody levels, which lead to better protection. Conclusions: The A/ZJU01/PR8/2013 split H7N9 avian influenza vaccine based on A/Zhejiang/DTID-ZJU01/2013(H7N9) is effective in protecting against highly pathogenic H7N9. H7N9 vaccine adjuvanted with MF59 offers better protection against infection with highly pathogenic H7N9. In order to make the H7N9 vaccine applicable to humans, further clinical trials are required to evaluate MF59 adjuvanted vaccine. Meanwhile, the vaccine strain should be updated based on the highly pathogenic H7N9 gene sequence.

Development and Characterization of Neutralizing Antibodies Against Zaire Ebolavirus Glycoprotein and Protein 40

Background/Aims: Monoclonal antibodies (mAbs) are presently the most promising treatment against Ebola virus disease (EVD), and cocktail of two or more antibodies likely confers protection through complementary mechanisms. Zaire Ebolavirus (EBOV) glycoprotein (GP) and viral protein 40 (VP40) are targets for designing neutralizing antibodies. Currently, the antiviral therapeutics of mAb-cocktails are still limited solely to anti-GP antibodies，there is no Abs cocktail against Zaire EBOV GP and VP40, which both have important interactions with host cellular membrane. Methods: We used hybridoma technology to produce anti-Zaire EBOV GP mAb against GP receptor binding domain, and anti-Zaire EBOV VP40 mAbs against the N-terminal domain, the C-terminal domain, respectively; synthesized Zaire EBOV transcription and replication competent virus like particles (trVLPs), which model even all aspects of the EBOV life cycles in order to evaluate the anti-viral effect of mAbs. Then, we characterized the anti- Zaire EBOV trVLPs effect of anti-GP and VP40 mAbs in vitro by real time-PCR, immunofluorescence assay and western blot analysis. Results: Our results demonstrate that anti-GP or anti-VP40 mAbs effectively inhibit trVLPs replication. The cocktails of anti-GP and anti-VP40 mAbs, or between anti-VP40 mAbs, had synergistic anti-trVLPs effect. Meanwhile, the detailed DNA and amino acid sequences of the mAbs were checked. Conclusion: The study verifies neutralizing efficacy of anti-GP or anti-VP40 mAb, report promising cocktail of anti-GP and anti-VP40 mAb, or cocktail of two anti-VP40 mAbs. To our knowledge, this is the first account to report the important anti-viral effect of cocktails of anti-GP and anti-VP40 mAbs in vitro.

The lifecycle of the Ebola virus in host cells

Ebola haemorrhagic fever causes deadly disease in humans and non-human primates resulting from infection with the Ebola virus (EBOV) genus of the family Filoviridae. However, the mechanisms of EBOV lifecycle in host cells, including viral entry, membrane fusion, RNP formation, GP-tetherin interaction, and VP40-inner leaflet association remain poorly understood. This review describes the biological functions of EBOV proteins and their roles in the lifecycle, summarizes the factors related to EBOV proteins or RNA expression throughout the different phases, and reviews advances with regards to the molecular events and mechanisms of the EBOV lifecycle. Furthermore, the review outlines the aspects remain unclear that urgently need to be solved in future research.Ebola haemorrhagic fever causes deadly disease in humans and non-human primates resulting from infection with the Ebola virus (EBOV) genus of the family Filoviridae. However, the mechanisms of EBOV lifecycle in host cells, including viral entry, membrane fusion, RNP formation, GP-tetherin interaction, and VP40-inner leaflet association remain poorly understood. This review describes the biological functions of EBOV proteins and their roles in the lifecycle, summarizes the factors related to EBOV proteins or RNA expression throughout the different phases, and reviews advances with regards to the molecular events and mechanisms of the EBOV lifecycle. Furthermore, the review outlines the aspects remain unclear that urgently need to be solved in future research.

Preclinical evaluation of the safety and pathogenicity of a live attenuated recombinant influenza A/H7N9 seed strain and corresponding MF59-adjuvanted split vaccine

Developing a safe and effective H7N9 influenza vaccine was initiated in early spring 2013, following human infections with a novel avian influenza A (H7N9) virus. In this study, a candidate H7N9 vaccine seed strain is produced using reverse genetics, with HA and NA derived from a human H7N9 virus and the remaining genes from the PR8 backbone virus which grows well in eggs. We verified that the virulence and transmissibility of the recombinant H7N9 vaccine seed strain were decreased as compared to wild-type H7N9 virus, to levels comparable with PR8. Using the seed virus, we produced a monovalent split influenza A (H7N9) MF59-adjuvanted vaccine that was immunogenic in mice. Our H7N9 vaccine is selected for clinical investigation and potential human use. To assess the safety of our H7N9 vaccine, we performed acute toxicity, repeated dose toxicity and active systemic anaphylaxis tests. Our results showed that, under the conditions used in this study, the NOEAL (no obvious adverse effect level) was 30 μg/0.5 mL.