The power and the promise of synthetic lethality for clinical application in cancer treatment.

Synthetic lethality is a phenomenon wherein the simultaneous deficiency of two or more genes results in cell death, while the deficiency of any individual gene does not lead to cell death. In recent years, synthetic lethality has emerged as a significant topic in the field of targeted cancer therapy, with certain drugs based on this concept exhibiting promising outcomes in clinical trials. Nevertheless, the presence of tumor heterogeneity and the intricate DNA repair mechanisms pose challenges to the effective implementation of synthetic lethality. This review aims to explore the concepts, development, and ethical quandaries surrounding synthetic lethality. Additionally, it will provide an in-depth analysis of the clinical application and underlying mechanism of synthetic lethality.

Identification and validation of functional roles for three MYC-associated genes in hepatocellular carcinoma.

BACKGROUND: Aberrations in MYC underlie a large proportion of liver hepatocellular carcinoma (LIHC) cases; however, MYC is difficult to target because of its undruggable structure. We aimed to uncover MYC-associated molecular targets to provide new strategies for LIHC treatment. METHODS: LIHC transcriptome datasets and clinical information were obtained from The Cancer Genome Atlas. A series of bioinformatics analyses were performed for 370 patients who were stratified based on the median MYC expression level (high-MYC group and low-MYC group). Correlation analysis was performed to determine relationships between the expression of key MYC-associated genes and prognosis, DNA promotor methylation, and immune cell infiltration. Gene ontology and Kyoto Encyclopedia of Genes and Genomes Pathway enrichment analyses were performed to elucidate the functions of these genes in LIHC. Their expression and functions in LIHC were further verified using transgenic mice overexpressing c-Myc under control of the hepatocyte-specific promoter (Alb-Cre). RESULTS: AURKB, CCNB2, and CDKN3 were overexpressed in LIHC patients with high MYC expression and were associated with poor prognosis. Upregulation of these 3 genes was significantly correlated with hypomethylated promoter status, advanced T stage, metastasis, and immune cell infiltration in LIHC patients. Functional enrichment analyses indicated that these genes participate in the "p53 signaling pathway" and "cell cycle". Furthermore, RT-PCR and IHC analysis revealed that their mRNA and protein expression levels were upregulated in an Alb-Cre;cMYClsl/- mouse model. Drugs that target these 3 MYC-related genes were identified. CONCLUSION: Taken together, our results identify biomarkers of potential utility for managing liver cancer therapy owing to their significance in tumorigenesis, proliferation, and tumor immunity.

Recent trends in the incidence and survival of stage I liver cancer: a surveillance, epidemiology, and end results analysis.

BACKGROUND: Improvements in screening and imaging technologies and treatment of liver disease have influenced the trend in diagnosis for stage I liver cancer. In this article, recent trends in age, incidence, tumour size, and survival of different stages of liver cancer are analysed. METHODS: Surveillance, Epidemiology, and end results data from the National Cancer Institute were used to analyse trends in age-adjusted incidence rate, mean tumour size at diagnosis, age at diagnosis, and 5-year survival probability for stage I liver cancer. RESULTS: Stage I cases of liver cancer increased most tremendously over the study period, with a greater increase from 2004 to 2012 following a smaller increase from 2012 to 2015. Moreover, the mean age of stage I liver cancer increased by 1.72 years from 2004 to 2015. The 5-year-overall survival for stage I liver cases worsened from 97.9% to 83.7% from 2004 to 2011, whereas the 10-year survival probability for stage I cases worsened from 97.3% in 2004 to 79.6% in 2006. Comparing with higher stage cases, stage I liver cancer were more likely to be females, be married, live in metro areas, receive chemotherapy, and carry medical insurance. CONCLUSIONS: The incidence of stage I liver cancer has increased over the study period, with an increase in age of diagnosis, decrease in tumour size, and generally stable overall survival rate with slight decrease. These trends emphasized the importance of early detection of liver cancer and regular screening and better treatment for high-risk populations.RESEARCH HIGHLIGHTSImprovements in screening and imaging technologies and treatment of liver disease have influenced the trend in diagnosis for liver cancer.Stage I cases of liver cancer increased most tremendously over the study period, with a greater increase from 2004 to 2012 following a smaller increase from 2012 to 2015.These trends emphasized the importance of early detection of liver cancer and regular screening and better treatment for high-risk populations.

Effects of dietary oligosaccharides on serum biochemical index, intestinal morphology, and antioxidant status in broilers.

In order to determine the effect of different oligosaccharides on growth performance, intestinal health, and antioxidant status of broilers, 240 1-day-old XiangHuang broilers were randomly distributed to 4 treatments with 6 replicates each. Birds were fed corn-soybean-based diets (CON), and birds in xylo-oligosaccharides (XOS), fructo-oligosaccharides (FOS), and iso-maltooligosaccharide (IMO) groups were given the basal diet supplemented with 200 mg/kg XOS, FOS, and IMO, respectively. Result showed that average daily gain (ADG) during the whole 5 weeks in FOS group was greater than that in control group (p < 0.05). Both breast and thigh muscle percentages were higher for birds fed XOS versus CON (p < 0.05). Oligosaccharides supplementation increased jejunal villus height compared with control group (p < 0.05). Malondialdehyde (MDA) concentration in breast muscle was lower for birds fed diet containing FOS versus CON (p < 0.05). Activities of total superoxide dismutase (T-SOD) in serum and thigh muscle were higher in IMO than in control group (p < 0.05). Serum T-SOD and breast muscle's glutathione peroxidase (GSH-Px) activity was higher in XOS compared with control group (p < 0.05). Conclusion, dietary oligosaccharides such as XOS, FOS, and IMO could improve intestinal health and antioxidant ability of muscle without affect growth performance in broilers.

Deciphering cell-cell interactions and communication in the tumor microenvironment and unraveling intratumoral genetic heterogeneity via single-cell genomic sequencing.

A tumor's heterogeneity has important implications in terms of its clonal origin, progression, stemness, and drug resistance. Therefore, because of its significance in treatment, it is important to understand the gene expression pattern of a single cell, track gene expression or mutation in heterogeneous cells, evaluate the clonal origin of cancer cells, and determine the selective evolution of different subpopulations of cancer cells. Researchers are able to trace a cell's mutation and identify different types of tumor cells by measuring the whole transcriptome with single-cell sequencing (scRNA-seq). This technology provides a better understanding of the molecular mechanisms driving tumor growth than that offered by traditional RNA sequencing methods. In addition, it has revealed changes in the mutations and functions of somatic cells as a tumor evolves; it has also clarified immune cell infiltration and activation. Research on scRNA-seq technology has recently advanced significantly, suggesting new strategies for the treatment of cancer. In short, cancer researchers have become increasingly dependent on scRNA-seq. This paper reviews the development, detection principles, and processes of scRNA-seq technology and their application in tumor research. It also considers potential clinical applications.

Heterogeneity helps us determine the clonal origin, progression, and drug resistance of cancer cells.The gene expression pattern of a single cell has important biological significance.scRNA-seq enables a better understanding of cancer cells' molecular mechanisms.scRNA-seq provides information about the entirety of a tumor from what we can learn about a single cell.

Isolation and Characterization of Encephalomyocarditis Virus from Dogs in China.

Encephalomyocarditis virus (EMCV) is as a potential zoonotic agent with a wide host range. Here, we describe an EMC virus isolate, identified as EMCV C15, which was successfully obtained from the serum of dogs from animal hospitals. Virus production in cell culture was confirmed by EMCV-specific real-time RT-PCR, indirect immunofluorescence assays and electron microscopy. In addition, the open reading frame sequence (ORF) of the EMCV C15 virus was determined. From sequence comparison and phylogenetic analysis among 24 reference EMCV strains, it appears that the EMCV C15 strain is closely genetically related to strain BEL2887A/91 (>99.0% nucleotide identity). In artificially challenged dogs, the heart and brain were important targets of EMCV C15. This study provides genetic and pathogenic characterization of the EMCV C15 strain isolated in Beijing and calls for sustained surveillance of EMCV infection in China to support better prevention and control of the disease.

Genome mining and motif truncation of glycoside hydrolase family 5 endo-ß-1,4-mannanase encoded by Aspergillus oryzae RIB40 for potential konjac flour hydrolysis or feed additive.

Two novel glycosyl hydrolase family 5 (GH5) ß-mannanases (AoMan5A and AoMan5B) were identified from Aspergillus oryzae RIB40 by genome mining. The AoMan5A contains a predicted family 1 carbohydrate binding module (CBM-1), located at its N-terminal. The AoMan5A, AoMan5B and truncated mutant AoMan5AΔCL (truncating the N-terminal CBM and linker of AoMan5A) were expressed retaining the N-terminus of the native protein in Pichia pastoris GS115 by pPIC9KM. The specific enzyme activity of the purified reAoMan5A, reAoMan5B and reAoMan5AΔCL towards locust bean gum at pH 3.6 and 40°C for 10min, was 8.3, 104.2 and 15.8U/mg, respectively. The temperature properties of the reAoMan5AΔCL were improved by truncating CBM. They can degrade the pretreated konjac flour and produce prebiotics. In addition, they had excellent stability under simulative gastric fluid and simulative prilling process. All these properties make these recombinant ß-mannanases potential additives for use in the food and feed industries.

Enhanced protective immune response to PCV2 subunit vaccine by co-administration of recombinant porcine IFN-γ in mice.

The capsid (Cap) protein of PCV2 is the major immunogenic protein that is crucial to induce PCV2-specific neutralizing antibodies and protective immunity; thus, it is a suitable target antigen for the research and development of genetically engineered vaccines against PCV2 infection. IFN-γ has exhibited potential efficacy as an immune adjuvant that enhances the immunogenicity of certain vaccines in experimental animal models. In this study, three recombinant proteins: PCV2-Cap protein, porcine IFN-γ (PoIFN-γ), and the fusion protein (Cap-PoIFN-γ) of PCV2-Cap protein and PoIFN-γ were respectively expressed in the baculovirus system, and analyzed by Western blot and indirect ELISA. Additionally, we evaluated the enhancement of the protective immune response to the Cap protein-based PCV2 subunit vaccine elicited by co-administration of PoIFN-γ in mice. Vaccination of mice with the PCV2-Cap+PoIFN-γ vaccine elicited significantly higher levels of PCV2-specific IPMA antibodies, neutralizing antibodies, and lymphocyte proliferative responses compared to the Cap-PoIFN-γ vaccine, the PCV2-Cap vaccine, and LG-strain. Following virulent PCV2 challenge, no viraemia was detected in all immunized groups, and the viral loads in lungs of the PCV2-Cap+PoIFN-γ group were significantly lower compared to the Cap-PoIFN-γ group, the LG-strain group, and the mock group, but slightly lower compared to the PCV2-Cap group. These findings suggested that PoIFN-γ substantially enhanced the protective immune response to the Cap protein-based PCV2 subunit vaccine, and that the PCV2-Cap+PoIFN-γ subunit vaccine potentially serves as an attractive candidate vaccine for the prevention and control of PCV2-associated diseases.

In vitro inhibition of transmissible gastroenteritis coronavirus replication in swine testicular cells by short hairpin RNAs targeting the ORF 7 gene.

BACKGROUND: Transmissible gastroenteritis (TGE) is a highly contagious viral disease of swine, characterized by severe vomiting, diarrhea, and high mortality. Currently, the vaccines for it are only partially effective and no specific drug is available for treatment of TGE virus (TGEV) infection. RNA interference has been confirmed as a new approach for controlling viral infections. In this study, the inhibitory effect of short hairpin RNAs (shRNAs) targeting the ORF 7 gene of TGEV on virus replication was examined. RESULTS: Four theoretically effective sequences of TGEV ORF 7 gene were designed and selected for construction of shRNA expression plasmids. In the reporter assays, three of four shRNA expression plasmids were able to inhibit significantly the expression of ORF 7 gene and replication of TGEV, as shown by real-time quantitative RT-PCR analysis of viral ORF 7 and N genes and detection of virus titers (TCID50/ml). Stable swine testicular (ST) cells expressing the shRNAs were established. Observation of the cytopathic effect and apoptosis, as well as a cell proliferation assay demonstrated that the three shRNAs were capable of protecting ST cells against TGEV destruction, with high specificity and efficiency. CONCLUSIONS: Our results indicated that plasmid-transcribed shRNAs targeting the ORF 7 gene in the TGEV genome effectively inhibited expression of the viral target gene and viral replication in vitro. These findings provide evidence that the shRNAs have potential therapeutic application for treatment of TGE.

Identification of two internal signal peptide sequences: critical for classical swine fever virus non-structural protein 2 to trans-localize to the endoplasmic reticulum.

BACKGROUND: The membrane topology and molecular mechanisms for endoplasmic reticulum (ER) localization of classical swine fever virus (CSFV) non-structural 2 (NS2) protien is unclear. We attempted to elucidate the subcellular localization, and the molecular mechanisms responsible for the localization of this protein in our study. The NS2 gene was amplified by reverse transcription polymerase chain reaction, with the transmembrane region and hydrophilicity of the NS2 protein was predicted by bioinformatics analysis. Twelve cDNAs of the NS2 gene were amplified by the PCR deletion method and cloned into a eukaryotic expression vector, which was transfected into a swine umbilical vein endothelial cell line (SUVEC). Subcellular localization of the NS2 protein was characterized by confocal microscopy, and western blots were carried out to analyze protein expression. RESULTS: Our results showed that the -NH2 terminal of the CSFV NS2 protein was highly hydrophobic and the protein localized in the ER. At least four transmembrane regions and two internal signal peptide sequences (amino acids103-138 and 220-262) were identified and thought to be critical for its trans-localization to the ER. CONCLUSIONS: This is the first study to identify the internal signal peptide sequences of the CSFV NS2 protein and its subcellular localization, providing the foundation for further exploration of this protein's function of this protein and its role in CSFV pathogenesis.

[Construction and immunogenicity of a recombinant adenovirus co-expressing the E2 protein of classical swine fever virus and the porcine interleukin 2 in rabbits].

To construct a recombinant adenovirus co-expressing the E2 protein of classical swine fever virus (CSFV) and the porcine interleukin 2 (pIL-2), the CSFV E2 gene and pIL-2 gene were amplified respectively from the plasmids pMD19-T-E2 and pMD19-T-pIL-2 by PCR. E2-pIL-2 fusion gene was obtained by using 5 consecutive glycine codons as a linker and cloned into the adenoviral shuttle plasmid AdTrack. The AdTrack-E2-pIL-2 was linearized and transformed into E. coli BJ5183 with the backbone plasmid AdEasy1. The resultant recombinant plasmid AdEasy-E2-pIL-2 was transfected into the 293 cells where the recombinant adenovirus rAd-E2-pIL-2 was produced. The immunogenicity of rAd-E2-pIL-2 was evaluated in rabbits. The results of RT-PCR and Western-blotting showed that rAd-E2-pIL-2 could carry and express E2 and pIL-2 proteins. The titer of the rAd-E2-pIL-2 was 10(8.12) PFU/mL. After immunized with rAd-E2pIL-2, The injected rabbits developed a high level of CSFV specific antibodies. Regular fever was not detected in the rAd-E2-pIL-2-immunized rabbits upon challenge with CSFV C stain, and specific lymphoproliferative responses to the CSFV was detected in the lymphocytes from the immunized rabbits. In conclusion, rAd-E2-pIL-2 was constructed successfully and it could be an attractive vaccine candidate against CSFV.

Classic swine fever virus NS2 protein leads to the induction of cell cycle arrest at S-phase and endoplasmic reticulum stress.

BACKGROUND: Classical swine fever (CSF) caused by virulent strains of Classical swine fever virus (CSFV) is a haemorrhagic disease of pigs, characterized by disseminated intravascular coagulation, thrombocytopoenia and immunosuppression, and the swine endothelial vascular cell is one of the CSFV target cells. In this report, we investigated the previously unknown subcellular localization and function of CSFV NS2 protein by examining its effects on cell growth and cell cycle progression. RESULTS: Stable swine umbilical vein endothelial cell line (SUVEC) expressing CSFV NS2 were established and showed that the protein localized to the endoplasmic reticulum (ER). Cellular analysis revealed that replication of NS2-expressing cell lines was inhibited by 20-30% due to cell cycle arrest at S-phase. The NS2 protein also induced ER stress and activated the nuclear transcription factor kappa B (NF-kappaB). A significant increase in cyclin A transcriptional levels was observed in NS2-expressing cells but was accompanied by a concomitant increase in the proteasomal degradation of cyclin A protein. Therefore, the induction of cell cycle arrest at S-phase by CSFV NS2 protein is associated with increased turnover of cyclin A protein rather than the down-regulation of cyclin A transcription. CONCLUSIONS: All the data suggest that CSFV NS2 protein modulate the cellular growth and cell cycle progression through inducing the S-phase arrest and provide a cellular environment that is advantageous for viral replication. These findings provide novel information on the function of the poorly characterized CSFV NS2 protein.

Up-regulation of integrin beta3 expression in porcine vascular endothelial cells cultured in vitro by classical swine fever virus.

Classical swine fever (CSF) caused by virulent strains of classical swine fever virus (CSFV) is a haemorrhagic disease of pigs, characterized by disseminated intravascular coagulation, thrombocytopenia and immunosuppression. The cell adhesion molecule, integrin beta3, plays a central role in maintaining and regulating vascular permeability. In view of the haemorrhagic pathology of the disease, the effect of CSFV infection on integrin beta3 expression was investigated using the swine umbilical vein endothelial cell (SUVEC) line, in conjunction with quantitative PCR and Western blotting techniques. Following infection, the expression levels of integrin beta3 were significantly up-regulated along with corresponding transcription levels. The infected endothelial cells adhered onto immobilized extracellular matrix (ECM) with more extensive spreading than that of the control, and such interaction was strongly inhibited by an anti-integrin beta3 monoclonal antibody (mAb). This study revealed the up-regulation of integrin beta3 in vascular endothelial cells by CSFV infection, and cell adhesion molecules of this kind possibly play an important role in the changes of haemostatic balance in haemorrhagic pathology of CSF.