Salmonella typhimurium VNP-20009 (VNP) is a non-pathogenic attenuated strain, which, as a facultative anaerobe, preferentially accumulates in hypoxic regions of solid tumors. Here, VNP was utilized as a delivery vehicle of the antitumor protein Lipidated azurin, Laz, which is produced by the meningitis-causing bacterium Neisseria meningitides. In brain cancer cells, Laz has been demonstrated to induce apoptosis through an interaction with the tumor suppressor protein p53. In this study, the laz gene, including its signal sequence, was cloned downstream of a hypoxia inducible promoter (HIP-1), before being electroporated into VNP. Successful ectopic expression and export of the Laz protein by VNP under hypoxic conditions were confirmed by Western blot analysis of the cell-free culture medium. Effective expression of Laz by VNP was investigated in two glioblastoma cell lines: LN-229 and U-373, with the latter line carrying a mutated version of p53; as well as in the breast cancer line MCF-7. Cytotoxicity of the VNP-Laz was assessed by determining the fluorescence of the apoptotic marker caspases 3/7. Compared to the purified Laz, VNP-Laz, significantly induced apoptosis in MCF-7, LN-229 and, to a much lower extent in U-373 cells, suggesting a p53-linked mechanism. Our results might represent a new approach of targeted gene delivery and suggest a potential application in brain tumor therapy.

Purpose A new locus, regO, involved in the regulation of photosynthesis gene expression in response to oxygen and light, has been studied in Rhodosprillum rubrum ATCC1117 (Rsp. rubrum) for identification of its function. Methods Inactivation of regO by interposon mutagenesis resulted in the inability of cells to grow photosynthetically, (i.e. become PS–). Protein domain analysis of RegO using the BLAST engine was also performed. Results The mutant strain was able to grow only anaerobically in the dark in the presence of DMSO as an external electron acceptor. Under these conditions, the mutant strain produced substantially lower amounts of photosynthetic membranes, indicating that regO is involved in the regulation of photosynthetic gene expression in response to anaerobiosis. The Rsp. rubrum REGO–disrupted mutant recovered the synthesis of photosynthetic membranes and retained regulation by light and/or oxygen tension when wild-type regO was provided in-trans. Protein domain analysis of RegO revealed that it encodes a multi-domain sensor histidine kinase (HK). The signal-input domains, or PAS domains, bear strong similarities to putative heme-bound sensors involved in sensing light, redox potential, and/or oxygen. The output HK domain exhibits strong homology to sensor domains from bacterial two-component systems involved in signal transduction in response to the same environmental signals. Conclusion regO is coding for a sensor histidine kinase that belongs to bacterial two-component systems responsible for signal transduction in response to light and oxygen, particularly in the absence of oxygen. It is believed to be involved in the regulation of tetrapyrrole biosynthesis, which was shown as a lack of photosynthetic membranes in the mutant strain REGO– .Unlike other sensor kinase homologues from related anoxygenic phototrophic bacterial species, although functionally similar to RegB and PrrB, RegO is predicted to lack transmembrane domains and is thus expected to be a cytosolic member of a two-component signal transduction system. RegO also differs from its functional homologues, Reg B/PrrB sensor protein kinases, of the two component systems in that it lacks the second component of this two-component signal transduction system found in the neighboring genes. That encouraged us to give it the name RegO, indicating the lack of a cognate response regulator similar to Reg A/PrrA on other closely related anoxygenic Rhodobacter species.

Background Inflammatory Bowel Disease (IBD) is a chronic autoimmune gastrointestinal disease, sub-classified into Crohn’s disease (CD) and ulcerative colitis (UC). The two subclasses are characterized by a relapsing-remitting course with an increasingly high incidence and prevalence worldwide. Molecular mechanisms guarding the pathogenesis of these diseases remain, to the present day, ambiguous to researchers. MicroRNAs are 22 nucleotides long small noncoding RNAs that have been recently described as essential participants in immune cell development and the immune response to pathogens. During the past decade, genetic and epigenetic studies in IBD have been labeled as essential; since endoscopic assessment and biopsies provide limited data concerning early disease activity, factors for relapse, and response to treatment. To the best of our knowledge, IBD research has never addressed miRNA profiles in Egyptian CD and UC patients as compared to unaffected controls. Methods Therefore, this study aims to profile miRNAs in Egyptian patients suffering from UC and CD, using RNA-seq of total RNA extracted from colonoscopically obtained tissue pinch biopsies. Results The sequencing results showed that 30 miRNAs were uniquely expressed in tissue biopsies obtained from the CD patients, as compared to only 14 uniquely expressed in UC patients. Further web-based functional enrichment analysis showed that the miRNAs- in both disease groups- are mainly involved in six interlinked molecular pathways; including the JAK/STAT, WNT, PI3K/AKT, FOXO, MAPK, and NF-κB signaling pathways. One of the most interesting findings of the current study is the fact that the downregulation of the miR-204-5p in UC patients (log2 FC= 5.05)-as compared to CD patients- may be caused by the sponging effect of the MALAT1 long non-coding RNA (lncRNA); affecting related signaling pathways such as the Wnt/β-catenin signaling. This suggests an essential interplay between miRNAs and lncRNAs in shaping the molecular pathogenesis of UC vs. CD. Conclusion The results of the current study revealed explicit-previously undetermined- differences in the miRNA profiles of patients suffering from UC and CD. Such results are expected to impact the understanding of the difference in the molecular pathogenesis of IBD subtypes affecting patients’ response to treatment.

Background: Malignant Mesothelioma is a rare and fatal cancer caused by uncontrolled growth and proliferation of pleural mesothelial cells and it is frequently diagnosed late. Furthermore, diagnosis can be difficult, which provides incentive for the investigation of new methods of diagnosis. Biomarkers are biological indicators of a biological state or disease. lncRNA have been found to be linked to the progression of mesothelioma. LncRNAs were discovered to be expressed differently across tissues and conditions, which suggests potential as biomarkers. Aim: we discuss the potential in using lncRNA as biomarkers in Mesothelioma, emphasizing on specific lncRNA that have already been explored and to clarify their diagnostic value. In order to narrow down all lncRNA markers investigated for mesothelioma, we conducted a systematic review of the literature on the subject. Methods: Searches were conducted through four databases (Pubmed, JStor, Mdpi and Sciencedirect) for articles in time frame between 2010 and 2022. The search criteria based on the keywords: “Mesothelioma”, “lncRNA” or “Long non coding RNA”. The study was evaluated by 2 researches independently. Screening of 1141 articles, only 3 articles were included for fulfilling the criteria. Quality Assessment was carried using Diagnostic Accuracy Studies (QUADAS)-2 Results: Three studies analyzed and confirmed the expression and diagnostic value of 4 lncRNAs (GAS5, lncRNA‐RP1‐86D1.3, SNHG8, POT1-AS1) by RT-qPCR in 96 patients of various ethnic backgrounds and gender groups. Conclusion: The present studies hold promise for LncRNAs as novel diagnostic markers for pleural mesothelioma. However, larger sample size and more standardized protocols are required for validation.

Purpose: A new locus, regO, involved in the regulation of photosynthesis gene expression in response to oxygen and light, has been studied in Rhodosprillum rubrum ATCC1117 (Rsp. rubrum) for identification of its function. Methods: Inactivation of regO by interposon mutagenesis resulted in the inability of cells to grow photosynthetically, (i.e. become PS–). Also Protein domain analysis of RegO was done using BLAST engine was also performed. Results: The mutant strain was able to grow only anaerobically in the dark in presence of DMSO as an external electron acceptor. Under these conditions, the mutant produced substantially lower amounts of photosynthetic membranes, indicating that regO is involved in photosynthetic gene expression in response to anaerobiosis. The Rsp. rubrum REGO– disrupted mutant recovered the synthesis of photosynthetic membranes, and retained regulation by light and/or oxygen tension, when wild type the regO gene was provided in-trans.Protein domain analysis of RegO revealed that it encodes a multi-domain sensor histidine kinase (HK). The signal-input, PAS domains, bear strong similarities to putative heme-bound sensors involved in sensing light, redox potential and/or oxygen. The output HK domain exhibits strong homology to sensor domains from bacterial two-component systems involved in signal transduction in response to the same environmental signalsConclusion: regO is sensor histidine kinase that belong to bacterial two-component systems responsible for signal transduction in response to light and oxygen in particularly absence of oxygen. It is belived to be involved in the regulation of terapyroll biosynthesis, which was shown as a lack of photosynthetic membranes in the mutant strain regO. Unlike other sensor kinase homologues from related anoxygenic phototrophic bacterial species, RegO is predicted to lack transmembrane domains and is thus expected to be a cytosolic member of a two-component signal transduction system.