PO-300 Unveiling and exploiting cancer stem cell editing and immunogenicity for precision medicine

Introduction Immunogenic chemotherapy (IC) induces immunogenic cell death (ICD), which, similar to viral infection, leads to a cancer-cell autonomous Type-I-Interferon (IFN-I) signalling. This immunological signature is crucial for effective antitumor responses but may paradoxically promote the emergence of a rare population of cancer stem cells (CSCs) acting as a chemoresistant niche within the tumour and roots for metastasis and relapse. In this study, we have investigated the role of IFN-I during IC in inducing a cancer editing program resulting in the appearance of poor immunogenic CSCs. Material and methods Human and murine tumour cell lines were treated in vitro with ICD-inducers or IFN-I as control and the induction of CSC were analysed by cytofluorometry, quantitative real time (qRT)-PCR, 3D culture and functional assays. Free and vesicle-mediated nucleic acid transfer during ICD has been characterised by co-culture experiments. IC-induced CSC immunogenicity has been studied through cytofluorometry, microfluidic devices and in vivo experiments. All experiments have been done in triplicate and statistical significance evaluated by two-tailed Student's t test and two-way ANOVA. Results and discussions The transient/acute induction of IFN-I during ICD is followed by the appearance of a rare population of CSCs. Both free nucleic acids and extracellular vesicles are released during tumour ICD constituting the upstream inducers of IFN-I-mediated reprogramming of neighbouring cells. IC-induced CSCs display epithelial-to-mesenchymal transition traits, multidrug resistance and regenerative properties, and a significant tumorigenic potential when inoculated in immunodeficient and immunocompetent mice. As expected, tumour growth and size are reduced in the presence of an intact immune system. Experiments on microfluidic devices reveal a poor immunogenic potential of CSCs, further confirmed by the expression of immune checkpoint blockers. Conclusion Our results pinpoint a surprising link between ICD, IFN-I and CSCs. Elucidating the mechanisms of CSC editing together with a deep characterisation of CSC (immune) properties could be crucial to prevent tumour relapse. This could undoubtedly have dramatic implications for the clinical management of cancer in an era of terrific development of precision combined chemo-immune therapy

Proteomic and ionomic profiling reveals significant alterations of protein expression and calcium homeostasis in cystic fibrosis cells

Cystic fibrosis (CF) is an autosomal recessive disorder associated with mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and defective chloride transport across the epithelial cell membranes. Abnormal epithelial ion transport is the primary cause of persistent airway infections and chronic inflammation in CF patients. In order to gain further insight into the mechanisms of epithelial dysfunctions linked to CFTR mutations, we performed and integrated proteomic and ionomic analysis of human bronchial epithelial IB3-1 cells and compared them with a CFTR-complemented isogenic cell line (C38). Aside from changes that were consistent with known effects related to CFTR mutations, such as differences in glycolytic and gluconeogenic pathways and unfolded protein responses, differential proteomics highlighted significant alteration of protein expression and, in particular, of the 14-3-3 signalling pathway that is known to be involved in cellular calcium (Ca) homeostasis. Of note, restoring chloride efflux by acting on Ca cellular homeostasis has been shown to be a promising therapeutic intervention for CF. Ionomic analysis showed significant changes in the IB3-1 element profile compared with C38 cells and in particular we observed an increase of intracellular Ca that significantly correlates with intracellular zinc (Zn) levels, suggesting a synergistic role of Ca and Zn influx. This finding is particularly intriguing because Zn has been reported to be effective in CF treatment increasing Ca influx. Taken together, our proteomic and ionomic data reveal that CFTR mutation sets in motion endogenous mechanisms counteracting impaired chloride transport mainly acting on epithelial ion transport and increasing intracellular Ca, suggesting potential links between protein expression and this response

Hyperthermic intraperitoneal chemotherapy in interval debulking surgery for advanced epithelial ovarian cancer: A single-center, real-life experience.

Background: An improvement in survival without increasing perioperative morbidity in patients with advanced epithelial ovarian cancer treated with hyperthermic intraperitoneal chemotherapy (HIPEC) after interval debulking surgery (IDS) has been recently demonstrated in a randomized controlled trial. This study was aimed at assessing the feasibility and perioperative outcomes of the use of HIPEC after IDS at a referral cancer center. Methods: Over the study period, 149 IDSs were performed. Patients who had at least International Federation of Gynecology and Obstetrics stage III disease, with <2.5 mm of residual disease (RD) at the end of surgery and were not participating in clinical trials received HIPEC. Moreover, specific exclusion criteria were considered. These patients were compared with 51 patients with similar clinical characteristics at the same institution and within the same timeframe who did not receive HIPEC. Results: No differences in patient or disease characteristics with the exception of the type of neoadjuvant chemotherapy (P =.002) were found between the 2 groups. As for surgical characteristics, significant differences were found in RD after IDS (P =.007) and in the duration of surgery (P <.001), whereas the bowel resection and diversion rates (P =.583 and P =.213, respectively) and the postoperative intensive care unit and hospital stays (P =.567 and P =.727, respectively) were comparable. The times to start adjuvant chemotherapy were also similar (P =.998). Equally, the rates of any grade of both intraoperative complications (P =.189) and early postoperative complications (P =.238) were superimposable. Conclusions: In the authors' experience, the addition of HIPEC to IDS is feasible in 35% for the population. This value might increase with changes in the inclusion/exclusion criteria. HIPEC does not increase perioperative complications and does not affect a patient's recovery or time to start adjuvant chemotherapy. HIPEC should be offered to select patients listed for IDS

Tuning the conductivity along atomic chains by selective chemisorption

Adsorption of Au on vicinal Si(111) surfaces results in growth of long-range ordered metallic quantum wires. In this paper, we utilized site-specific and selective adsorption of oxygen to modify chemically the transport via different channels in the systems Si(553)-Au and Si(557)-Au. They were analyzed by electron diffraction and four-tip STM-based transport experiments. Modeling of the adsorption process by density functional theory shows that the adatoms and rest atoms on Si(557)-Au provide energetically favored adsorption sites, which predominantly alter the transport along the wire direction. Since this structural motif is missing on Si(553)-Au, the transport channels remain almost unaffected by oxidation. © 2017 American Physical Society.DFG/FOR/170

Structural characterization of the Xi class glutathione transferase from the haloalkaliphilic archaeon Natrialba magadii

Xi class glutathione transferases (GSTs) are a recently identified group, within this large superfamily of enzymes, specifically endowed with glutathione-dependent reductase activity on glutathionyl-hydroquinone. Enzymes belonging to this group are widely distributed in bacteria, fungi, and plants but not in higher eukaryotes. Xi class GSTs are also frequently found in archaea and here we focus on the enzyme produced by the extreme haloalkaliphilic archaeon Natrialba magadii (NmGHR). We investigated its function and stability and determined its 3D structure in the apo form by X-ray crystallography. NmGHR displays the same fold of its mesophilic counterparts, is enriched in negatively charged residues, which are evenly distributed along the surface of the protein, and is characterized by a peculiar distribution of hydrophobic residues. A distinctive feature of haloalkaliphilic archaea is their preference for γ-glutamyl-cysteine over glutathione as a reducing thiol. Indeed we found that the N. magadii genome lacks a gene coding for glutathione synthase. Analysis of NmGHR structure suggests that the thiol binding site (G-site) of the enzyme is well suited for hosting γ-glutamyl-cysteine

p63 isoforms regulate metabolism of cancer stem cells

p63 is an important regulator of epithelial development expressed in different variants containing (TA) or lacking (\u394N) the N-terminal transactivation domain. The different isoforms regulate stem-cell renewal and differentiation as well as cell senescence. Several studies indicate that p63 isoforms also play a role in cancer development; however, very little is known about the role played by p63 in regulating the cancer stem phenotype. Here we investigate the cellular signals regulated by TAp63 and \u394Np63 in a model of epithelial cancer stem cells. To this end, we used colon cancer stem cells, overexpressing either TAp63 or \u394Np63 isoforms, to carry out a proteomic study by chemical-labeling approach coupled to network analysis. Our results indicate that p63 is implicated in a wide range of biological processes, including metabolism. This was further investigated by a targeted strategy at both protein and metabolite levels. The overall data show that TAp63 overexpressing cells are more glycolytic-active than \u394Np63 cells, indicating that the two isoforms may regulate the key steps of glycolysis in an opposite manner. The mass-spectrometry proteomics data of the study have been deposited to the ProteomeXchange Consortium (http://proteomecentral. proteomexchange.org) via the PRIDE partner repository with data set identifiers PXD000769 and PXD000768

Prevalence and severity of airway obstruction in an Italian adult population

Background. This study sets out to estimate the prevalence and the degree of severity of bronchial obstruction in an adult population with three different diagnostic criteria: the European Respiratory Society (ERS), the American Thoracic Society (ATS), and the World Health Organization (WHO) defined as Global Obstructive Lung Disease (GOLD). Methods. 1514 subjects underwent complete medical evaluation and spirometry. Results. The prevalence of bronchial obstruction was respectively 27.5% (ERS), 33% (GOLD), and 47.3% (ATS). The prevalence of bronchial obstruction in the smoker group was 33.4% (ERS), 38.1% (GOLD), and 52.3% (ATS). The prevalence of obstruction in the ex-smoker group was 33% (ERS), 41.4% (GOLD), and 57.1% (ATS). The prevalence of obstruction in the non-smoker group was 21.1% (ERS), 24.9% (GOLD), and 38.6% (ATS). Conclusions. The results show that the prevalence of airway obstruction increases proportionally with age; the cigarette smoking represents an important conditioning factor. These observations warrant the necessity of a more complete and multi-parametric analysis in the evaluation of patients with airway obstruction using methodologies that explore the functional state and the risk factors that cause the airway obstruction

Prevalence and severity of airway obstruction in an Italian adult population

Background. This study sets out to estimate the prevalence and the degree of severity of bronchial obstruction in an adult population with three different diagnostic criteria: the European Respiratory Society (ERS), the American Thoracic Society (ATS), and the World Health Organization (WHO) defined as Global Obstructive Lung Disease (GOLD). Methods. 1514 subjects underwent complete medical evaluation and spirometry. Results. The prevalence of bronchial obstruction was respectively 27.5% (ERS), 33% (GOLD), and 47.3% (ATS). The prevalence of bronchial obstruction in the smoker group was 33.4% (ERS), 38.1% (GOLD), and 52.3% (ATS). The prevalence of obstruction in the ex-smoker group was 33% (ERS), 41.4% (GOLD), and 57.1% (ATS). The prevalence of obstruction in the non-smoker group was 21.1% (ERS), 24.9% (GOLD), and 38.6% (ATS). Conclusions. The results show that the prevalence of airway obstruction increases proportionally with age; the cigarette smoking represents an important conditioning factor. These observations warrant the necessity of a more complete and multi-parametric analysis in the evaluation of patients with airway obstruction using methodologies that explore the functional state and the risk factors that cause the airway obstruction

miR-205-5p-mediated downregulation of ErbB/HER receptors in breast cancer stem cells results in targeted therapy resistance

The ErbB tyrosine kinase receptor family has been shown to have an important role in tumorigenesis, and the expression of its receptor members is frequently deregulated in many types of solid tumors. Various drugs targeting these receptors have been approved for cancer treatment. Particularly, in breast cancer, anti-Her2/EGFR molecules represent the standard therapy for Her2-positive malignancies. However, in a number of cases, the tumor relapses or progresses thus suggesting that not all cancer cells have been targeted. One possibility is that a subset of cells capable of regenerating the tumor, such as cancer stem cells (CSCs), may not respond to these therapeutic agents. Accumulating evidences indicate that miR-205-5p is significantly downregulated in breast tumors compared with normal breast tissue and acts as a tumor suppressor directly targeting oncogenes such as Zeb1 and ErbB3. In this study, we report that miR-205-5p is highly expressed in BCSCs and represses directly ERBB2 and indirectly EGFR leading to resistance to targeted therapy. Furthermore, we show that miR-205-5p directly regulates the expression of p63 which is in turn involved in the EGFR expression suggesting a miR-205/p63/EGFR regulation