A mouse model to study inducible oncogene cooperation <i>in vivo</i>

The current model for cancer development envisions cells under going a series of genetic mutations and/or alterations which result in their inability to respond normally to intracellular and extracellular signals that control proliferation, differentiation and death. The number of required genetic alterations varies for different types of cancer and it is likely that further changes occur during its progression to increased malignancy. Thus, cancer is not a static disease but during the development and progression of tumour, multiple changes occur in two kinds of genes: oncogenes and tumour suppressor genes. Oncogene-products can be classified as growth factors, growth factor receptors, Ras oncoproteins, cytoplasmic protein kinases, transcription factors, anti-apoptotic proteins. In particular, the ras oncogene family includes three members: N-ras, K-ras, H-ras. In non-transformed cells, Ras protein, belonging to G-protein family, transduces growth signals from external to the internal environment. In fact, when activated, Ras exchanges GDP with GTP and this allosteric change allows binding of Ras effector molecules and transduction of signalling cascades.R as activity is required for cell cycle progression. In cancer it has been observed that this oncogene is constitutively activated by mutations and induces the cell to enter into cell-cycle also in the absence of growth signals. Among the transcription factors, a gene involved in many tumours is myc. This transcription factor plays a key role in cell proliferation as its target proteins include many positive regulators of the cell-cycle. In tumour cells the protein product of this oncogene is overexpressed. The cooperationb etweenm ultiple oncogenesa nd/orl oss of tumour suppressors from different functional classes is necessary for transformation to proceed. In fact, it was observed that, although overexpression of a single oncogene does not transform wild-type mouse embryonic fibroblasts, combinations of myc and H-rasVAL12, can induce cellular transformation and the cells expressing both oncogenes displayeda markedp roliferative advantage. In thyroid, neoplastic transformation generates several different histotypes of tumours, ranging from poorly aggressive and well-differentiated, to highly malignant and undifferentiated anaplastic cancers. The aim of my thesis was to study the tumorigenesis induced by oncogenes and the oncogene cooperation in vivo during the gradual passage from a poorly aggressive to a much more aggressive tumour. To this end a mouse model expressing the two oncogenes H-rasVAL12 and c-myc (referred as ras and myc) in a tissue-specific as well as in a conditional manner was generated. For this purpose, the coding sequences of the two oncogenes were fused in a bicistronic construct and an IRES (Internal Ribosome Entry Sequence or Site) was inserted between them, to ensure the expression of the second oncogene. The construct was inserted under the control of the promoter of the ubiquitously expressed genes ROSA26 and Eeflal. In order to express these oncogenes in a tissue-specific manner, the transcription of the two oncogenesis preventedb y a STOP sequencef lanked by two LoxP sites. Such a STOP sequence can be removed by Cre recombinase protein. The transgenic mice were crossed with mice expressing Cre in a tissue-specific manner. Two strains of transgenic mice expressing Cre in thyroid cells were used: 1. transgenic mice for TgCre, in which Cre is expressed under the control of Tg promoter after the development of the thyroid; 2. Pax8Cre, in which the Cre sequence is inserted in the Pax8 locus and is expressed during the early stages of the thyroid development. In such a manner the oncogenes were expressed only in thyroid cells, but were still inactive. In particular, ras was fused to the mutated ligand binding domain of the estradiol receptor that is sensitive to tamoxifen and not to endogenous estradiol; while mycwas fused to the mutated ligand binding domain of the progesterone receptor (hPR891) that is sensitive to RU486 and not to endogenous progesterone. With thesef usedo ncogeneist is possible to activate only Ras( with tamoxifen) or only Myc (with RU486) or both (providing both tamoxifen and RU486). Moreover the activity of two oncogenes might be used to immortalize mouse cell lines in culture.</br

Calcium regulates HCC proliferation as well as EGFR recycling/degradation and could be a new therapeutic target in HCC

Calcium is the most abundant element in the human body. Its role is essential in physiological and biochemical processes such as signal transduction from outside to inside the cell between the cells of an organ, as well as the release of neurotransmitters from neurons, muscle contraction, fertilization, bone building, and blood clotting. As a result, intra- and extracellular calcium levels are tightly regulated by the body. The liver is the most specialized organ of the body, as its functions, carried out by hepatocytes, are strongly governed by calcium ions. In this work, we analyze the role of calcium in human hepatoma (HCC) cell lines harboring a wild type form of the Epidermal Growth Factor Receptor (EGFR), particularly its role in proliferation and in EGFR downmodulation. Our results highlight that calcium is involved in the proliferative capability of HCC cells, as its subtraction is responsible for EGFR degradation by proteasome machinery and, as a consequence, for EGFR intracellular signaling downregulation. However, calcium-regulated EGFR signaling is cell line-dependent. In cells responding weakly to the epidermal growth factor (EGF), calcium seems to have an opposite effect on EGFR internalization/degradation mechanisms. These results suggest that besides EGFR, calcium could be a new therapeutic target in HCC

Natural History and Management of Familial Paraganglioma Syndrome Type 1: Long-Term Data from a Large Family

Head and neck paragangliomas are the most common clinical features of familial paraganglioma syndrome type 1 caused by succinate dehydrogenase complex subunit D (SDHD) mutation. The clinical management of this syndrome is still unclear. In this study we propose a diagnostic algorithm for SDHD mutation carriers based on our family case series and literature review. After genetic diagnosis, first evaluation should include biochemical examination and whole-body imaging. In case of lesion detection, nuclear medicine examination is required for staging and tumor characterization. The study summarizes the diagnostic accuracy of different functional imaging techniques in SDHD mutation carriers. 18F-3,4-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET)-computed tomography (CT) is considered the gold standard. If it is not available, 123I-Metaiodobenzylguanidine (MIBG) could be used also for predicting response to radiometabolic therapy. 18F-fluoro-2-deoxy-D-glucose (18F-FDG) PET-CT has a prognostic role since high uptake identifies more aggressive cases. Finally, 68Ga-peptides PET-CT is a promising diagnostic technique, demonstrating the best diagnostic accuracy in our and in other published case series, even if this finding still needs to be confirmed in larger studies. Periodic follow-up should consist of annual biochemical and ultrasonographic screening and biannual magnetic resonance examination to identify biochemical silent tumors early

Spicy food for the egg-cowries: the evolution of corallivory in the Ovulidae (Gastropoda: Cypraeoidea)

IntroductionHost-parasite associations provide very useful models to study adaptive processes. We investigated the interaction between carnivorous marine gastropods, the Ovulidae or egg-cowries, and their cnidarian food targets. Ovulidae (Fleming, 1828), is a family of specialized carnivorous caenogastropods that feed by browsing on octocorals (Anthozoa: Octocorallia: Malacalcyonacea and Scleralcyonacea) or, to a much lesser degree, on antipatharians (Anthozoa: Hexacorallia: Antipatharia) and Stylasteridae (Hydrozoa: Hydroidolina: Anthoathecata). Very scanty information is available on the phylogenetic relationships and the degree of specificity of the relationship with the cnidarians of this corallivorous lineage, especially for deep-water taxa.MethodsTo assess taxonomic identifications and investigate cnidarian/ovulid relationships in the context of their evolution, we generated an extensive molecular dataset comprising two mitochondrial (cox1 and 16S rDNA) and one nuclear gene (28S rDNA) from 524 specimens collected worldwide. The coral hosts of the ovulid species have been identified by integrating literature data with new records, employing morphological and/or molecular (the mitochondrial 16S rDNA and mtMSH, and the nuclear ITS2) markers.ResultsWe obtained a molecular phylogenetic framework for the Ovulidae, time-calibrated with nine reliable fossil records. An ancestral state reconstruction allowed to identify Hexacorallia or Hydroidolina as the most likely ancestral cnidarian host for the Ovulidae.DiscussionOur phylogenetic hypothesis revealed the existence of groups that do not completely correspond to the currently employed subfamilial arrangement. Concerning trophic ecology, while only pediculariines (Pedicularia and allied) are associated with hydrozoans (Stylasteridae), our results suggest that some ovulid lineages shifted independently between octocorals and hexacorals

Efficacy of CAR-T immunotherapy in MET overexpressing tumors not eligible for anti-MET targeted therapy

Aberrant activation of the MET receptor in cancer is sustained by genetic alterations or, more frequently, by transcriptional upregulations. A fraction of MET-amplified or mutated tumors are sensible to MET targeting agents, but their responsiveness is typically short-lasting, as secondary resistance eventually occurs. Since in the absence of genetic alterations MET is usually not a tumor driver, MET overexpressing tumors are not/poorly responsive to MET targeted therapies. Consequently, the vast majority of tumors exhibiting MET activation still represent an unmet medical need

Quality of Life in Patients with Neuroendocrine Neoplasms: The Role of Severity, Clinical Heterogeneity and Resilience

Context Although health-related quality of life (HRQoL) is a fundamental outcome in oncological clinical trials, its evaluation in the neuroendocrine neoplasm (NEN) research field is still limited. Objectives This study assessed the role of clinical severity (i.e., presence or absence of metastasis and lines of therapies) and heterogeneity (i.e., primary site, types of therapy, biology and surgery) of NEN in relation to HRQoL, as well as resilience as a moderator between clinical severity and HRQoL. Design Cross-sectional multicentric study. Setting Italian university hospitals. Patients 99 Italian patients (53 men and 46 women) with a NEN ranged in age from 22 to 79 years old. Main Outcome Measure Severity and heterogeneity of NENs, HRQoL and resilience. Results The presence of metastasis and a greater number of therapies affected the global health and some physical symptoms. Resilience was associated with global health, functional status and some physical symptoms, and moderated the impact of metastases on constipation and of the multiple therapies on diarrhea and financial problems. Patients with NEN in districts other than the gastro-entero-pancreatic system and those in follow-up perceived fewer physical symptoms than their counterparts. Patients with a sporadic NEN perceived their functional status, global health and disease-related worries as better than those with a hereditary NEN. Patients who underwent surgery were lower in constipation than their counterparts. Conclusion These findings highlight the need to assess the relationships between the clinical severity and heterogeneity of NEN with HRQoL and the role of resilience in improving patients’ HRQoL