H2A.Z overexpression suppresses senescence and chemosensitivity in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most intractable and devastating malignant tumors. Epigenetic modifications such as DNA methylation and histone modification regulate tumor initiation and progression. However, the contribution of histone variants in PDAC is unknown. Here, we demonstrated that the histone variant H2A.Z is highly expressed in PDAC cell lines and PDAC patients and that its overexpression correlates with poor prognosis. Moreover, all three H2A.Z isoforms (H2A.Z.1, H2A.Z.2.1, and H2A.Z.2.2) are highly expressed in PDAC cell lines and PDAC patients. Knockdown of these H2A.Z isoforms in PDAC cell lines induces a senescent phenotype, cell cycle arrest in phase G2/M, increased expression of cyclin-dependent kinase inhibitor CDKN2A/p16, SA-β-galactosidase activity and interleukin 8 production. Transcriptome analysis of H2A.Z-depleted PDAC cells showed altered gene expression in fatty acid biosynthesis pathways and those that regulate cell cycle and DNA damage repair. Importantly, depletion of H2A.Z isoforms reduces the tumor size in a mouse xenograft model in vivo and sensitizes PDAC cells to gemcitabine. Overexpression of H2A.Z.1 and H2A.Z.2.1 more than H2A.Z.2.2 partially restores the oncogenic phenotype. Therefore, our data suggest that overexpression of H2A.Z isoforms enables cells to overcome the oncoprotective barrier associated with senescence, favoring PDAC tumor grow and chemoresistance. These results make H2A.Z a potential candidate as a diagnostic biomarker and therapeutic target for PDAC

Recombinant Protein Expression and Purification of N, S1, and RBD of SARS-CoV-2 from Mammalian Cells and Their Potential Applications

The coronavirus disease 2019 (COVID-19) pandemic has reached an unprecedented level. There is a strong demand for diagnostic and serological supplies worldwide, making it necessary for countries to establish their own technologies to produce high-quality biomolecules. The two main viral antigens used for the diagnostics for severe acute respiratory syndrome coronavirus (SARS-CoV-2) are the structural proteins spike (S) protein and nucleocapsid (N) protein. The spike protein of SARS-CoV-2 is cleaved into S1 and S2, in which the S1 subunit has the receptor-binding domain (RBD), which induces the production of neutralizing antibodies, whereas nucleocapsid is an ideal target for viral antigen-based detection. In this study, we designed plasmids, pcDNA3.1/S1 and pcDNA3.1/N, and optimized their expression of the recombinant S1 and N proteins from SARS-CoV-2 in a mammalian system. The RBD was used as a control. The antigens were successfully purified from Expi293 cells, with high yields of the S1, N, and RBD proteins. The immunogenic abilities of these proteins were demonstrated in a mouse model. Further, enzyme-linked immunosorbent assays with human serum samples showed that the SARS-CoV-2 antigens are a suitable alternative for serological assays to identify patients infected with COVID-19

Granulocyte-macrophage colony-stimulating factor does not increase the potency or efficacy of a foot-and-mouth disease virus subunit vaccine Fator estimulante de colônias de granu-lócitos e macrófagos (GM-CSF) não aumenta a eficácia ou potência da vacina de subunidades da febre aftosa em suínos

Foot-and-mouth disease (FMD) is one of the most feared diseases of livestock worldwide. Vaccination has been a very effective weapon in controlling the disease, however a number of concerns with the current vaccine including the inability of approved diagnostic tests to reliably distinguish vaccinated from infected animals and the need for high containment facilities for vaccine production, have limited its use during outbreaks in countries previously free of the disease. A number of FMD vaccine candidates have been tested and a replication-defective human adenovirus type 5 (Ad5) vector containing the FMDV capsid (P1-2A) and 3C protease coding regions has been shown to completely protect pigs against challenge with the homologous virus (FMDV A12 and A24). An Ad5-P1-2A+3C vaccine for FMDV O1 Campos (Ad5-O1C), however, only induced a low FMDV-specific neutralizing antibody response in swine potency tests. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been successfully used to stimulate the immune response in vaccine formulations against a number of diseases, including HIV, hepatitis C and B. To attempt to improve the FMDV-specific immune response induced by Ad5-O1C, we inoculated swine with Ad5-O1C and an Ad5 vector containing the gene for porcine GM-CSF (pGM-CSF). However, in the conditions used in this trial, pGM-CSF did not improve the immune response to Ad5-O1C and adversely affected the level of protection of swine challenged with homologous FMDV.<br>A febre aftosa é uma das doenças mais temidas nos rebanhos em todo o mundo. A vacinação tem sido uma arma eficiente no controle da doença, no entanto há preocupações com as vacinas atualmente utilizadas incluindo a necessidade de instalações de alta segurança para a produção dessas vacinas e a falta de um teste de diagnóstico aprovado que faça distinção precisa entre animais vacinados dos infectados. Várias vacinas têm sido testadas contra a febre aftosa e uma dessas utiliza como vetor um vírus defectivo para replicação, derivado do adenovírus humano tipo 5 (Ad5), o qual contém as proteínas que compõe capsídeo do vírus da febre aftosa (P1-2A) e a protease 3C, protegeu completamente suínos contra o desafio de uma cepa homóloga (A12 e A24). Uma vacina com o Ad5-P1-2A+3C proveniente da cepa O1 Campos (Ad5-O1C), no entanto, somente induziu um baixo título de anticorpos neutralizantes específicos em testes de potência vacinal em suínos. O fator estimulante de colônias de granulócitos e macrófagos (GM-CSF) tem sido utilizado com sucesso na formulação de vacinas para estimular a resposta imune contra inúmeras doenças, incluindo HIV, Hepatite C e B. Na tentativa de melhorar a resposta imune específica contra a febre aftosa induzida pelo Ad5-O1C, suínos foram vacinados com Ad5-O1C juntamente com Ad5-GM-CSFporcino. Entretanto nas, condições utilizadas nesse teste, o GM-CSF suíno não melhorou a resposta imune do Ad5-O1C e adversamente afetou o nível de proteção de suínos desafiados com o vírus homólogo da febre aftosa