Triple-negative breast cancer cells respond to T cells severely at the alternative splicing layer

BACKGROUND: Cross talk of tumor­immune cells at the gene expression level has been an area of intense research. However, it is largely unknown at the alternative splicing level which has been found to play important roles in the tumor­immune microenvironment. RESULTS: Here, we re-exploited one transcriptomic dataset to gain insight into tumor­immune interactions from the point of AS level. Our results showed that the AS profiles of triple-negative breast cancer cells co-cultured with activated T cells were significantly changed but not Estrogen receptor positive cells. We further suggested that the alteration in AS profiles in triple-negative breast cancer cells was largely caused by activated T cells rather than paracrine factors from activated T cells. Biological pathway analyses showed that translation initiation and tRNA aminoacylation pathways were most disturbed with T cell treatment. We also established an approach largely based on the AS factor­AS events associations and identified LSM7, an alternative splicing factor, may be responsible for the major altered events. CONCLUSIONS: Our study reveals the notable differences of response to T cells among breast cancer types which may facilitate the development or improvement of tumor immunotherapy.

Natural transovarial transmission of dengue virus 4 in Aedes aegypti from Cuiabá, State of Mato Grosso, Brazil

INTRODUCTION: Dengue is the most prevalent arboviral disease in tropical areas. In Mato Grosso, outbreaks are reported every year, but studies on dengue in this state are scarce. METHODS: Natural transovarial infection of Aedes aegypti by a flavivirus was investigated in the Jardim Industriário neighborhood of Cuiabá, Mato Grosso. Eggs were collected with ovitraps during the dry, intermediate, and rainy seasons of 2012. After the eggs hatched and the larvae developed to adulthood, mosquitoes (n = 758) were identified and allocated to pools of 1-10 specimens according to the collection location, sex, and climatic period. After RNA extraction, multiplex semi-nested RT-PCR was performed to detect the four dengue virus (DENV) serotypes, yellow fever virus, West Nile virus and Saint Louis encephalitis virus. RESULTS: DENV-4 was the only flavivirus detected, and it was found in 8/50 pools (16.0%). Three of the positive pools contained females, and five contained males. Their nucleotide sequences presented 96-100% similarity with DENV-4 genotype II strains from Manaus, Amazonas. The minimum infection rate was 10.5 per 1000 specimens, and the maximum likelihood estimator of the infection rate was 11.6 (95% confidence interval: 4.8; 23.3). CONCLUSIONS: This study provides the first evidence of natural transovarial infection by DENV-4 in Ae. Aegypti in Mato Grosso, suggesting that this type of infection might serve as a mechanism of virus maintenance during interepidemic periods in Cuiabá, a city where dengue epidemics are reported every year. These results emphasize the need for efficient vector population control measures to prevent arbovirus outbreaks in the state. .

The Role of Intracellular Signaling Pathways in the Neurobiology of the Depressive Disorder

Major depressive disorder is characterized by cellular and molecular alterations resulting in the depressive behavioral phenotypes. Preclinical and clinical studies have demonstrated the deficits, including cell atrophy and loss, in limbic and cortical regions of patients with depression, which is restored with antidepressants by reestablishing proper molecular changes. These findings have implicated the involvement of relevant intracellular signaling pathways in the pathogenetic and therapeutic mechanisms of depressive disorders. This review summarizes the current knowledge of the signal transduction mechanisms related to depressive disorders, including cyclic-AMP, mitogen-activated protein kinase, Akt, and protein translation initiation signaling cascades. Understanding molecular components of signaling pathways regulating neurobiology of depressive disorders may provide the novel targets for the development of more efficacious treatment modalities.

Improved expression and catalytic efficiency of (R)-carbonyl reductase in Escherichia coli by secondary structure optimization of mRNA translation initiation region / 生物工程学报

To improve the expression level and catalytic efficiency of (R)-carbonyl reductase from Candida parapsilosis in Escherichia coli, we optimized the mRNA secondary structure of (R)-carbonyl reductase gene in translation initiation region (from +1 to +78), and constructed the corresponding variant. The formation of hairpin structure was significantly reduced and the Gibbs free energy was dramatically decreased from -9.5 kcal/mol to -5.0 kcal/mol after optimization. As a result, the expression level of (R)-carbonyl reductase in the variant was increased by 4-5 times and its specific activity in cell-free extract was enhanced by 61.9% compared to the wild-type strain. When using the whole cells as catalyst and 2-hydroxyacetophenone as substrate with a high concentration of 5.0 g/L, the variant showed excellent performance to give (R)-1-phenyl-1, 2-ethanediol with optical purity of 93.1% enantiomeric excess and a yield of 81.8%, which were increased by 27.5% and 40.5% respectively than those of the wild-type. In conclusion, the optimization of mRNA secondary structure in translation initiation region can overcome the steric hindrance of translation startup, promote translation smoothly to acquire high expression of target protein, and favor protein folding correctly to efficiently improve the enzyme specific activity and biotransformation function.

Effect of structural domain II of HCV 5' noncoding region on its translation initiation activity / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To examine the role of domain II of hepatitis C virus (HCV) 5' noncoding region (5' NCR) in its translation initiation activity.</p><p><b>METHODS</b>The fragment of HCV 5' NCR with deletions of 5'-proximal 118 nucleotides were amplified with PCR, then was used to substitute for the full length HCV 5' NCR of plasmid pCMVNCRluc, a firefly luciferase (Fluc) eukaryotic expression plasmid regulated by HCV 5' NCR, to generate recombinant plasmid pCNl-d3. pCMVNCRluc, pCNl-d2 (modified pCMVNCRluc with deletions of HCV 5' NCR ntl-43) and pCNl-d3 were transfected into HepG2 cells with liposome transfection protocol, respectively, and the relative luciferase activity was measured to analyze the regulatory effect of the truncated 5'NCR on Flue gene expression. Meanwhile the Flue mRNA levels were detected by RT-PCR.</p><p><b>RESULTS</b>The recombinant plasmid was successfully constructed. The Flue mRNA levels of the 3 plasmids were not significantly different (P > 0.05), and there were also no significant difference between the relative luciferase activity of plasmids pCNl-d2 and pCMVNCRluc (P > 0.05). However, that of pCNl-d3 was decreased significantly (P < 0.01, compared with pCNl-d2 or pCMVNCRluc).</p><p><b>CONCLUSION</b>Structural domain II of HCV 5' NCR plays an important role in its translation initiation activity.</p>

Translational control of human interferon alpha 1 gene expression in E.coli / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To increase prokaryotic expression level of IFN-alpha 1C gene through the quantitative theory of translational control and the translational enhancer sequence.</p><p><b>METHODS</b>Stepwise polymerase chain reaction (PCR) was used to alter the 5 terminal cDNA sequence of IFN-alpha 1C in three different grades of base mutation. In this way, the free energy (Delta G) of the secondary structure in translational initiation region (TIR) was decreased gradually. An expression plasmid (pBVE) was constructed to contain the translational enhancer cDNA sequence by modifying pBV220 upstream of the SD region.</p><p><b>RESULTS</b>The expression levels of three kinds of IFN-alpha 1C modified gene were all increased. Furthermore, it presented an increasing trend with decreasing in delta G varying from -50,241.6 to -22,190.0 J/mol. The highest expression was 2.43 x 10(8) U/L, covering twelve times more than its original cDNA. IFN-alpha 1C gene and its modified cDNA was inserted into pBVE as reporting genes. E.Coli cells harbouring pBVE/IFN-alpha 1Cs cDNA produced two to five times more IFN than cells harbouring pBV220/IFN-alpha 1Cs.</p><p><b>CONCLUSIONS</b>pBVE containing translational enhancer is a high level prokaryotic expression vector. The theory of quantitative translational control can effectively be used to enhance the IFN-alpha 1C gene expression level in E.coli.</p>