Effects of microgravity and oxidative stress on human T lymphocytes: different approaches to study their protein expression and post-translational modifications

The aim of this research project was to study the protein expression and post-translational modifications of human T cells exposed to microgravity and oxidative stress. We analysed components of the IL2/IL-2R signalling system and cytoskeletal components known to be negatively affected by microgravity. Little information is available regarding changes in phosphorylation and their functional consequences in T cells subjected to microgravity. This data could be a valuable indicator of microgravity's impact on cellular metabolism. Clinical problems related to disturbed immune cell functions in astronauts during long-term space flights could be anticipated and prevented. Many pathologies seem to be directly or indirectly linked to oxidative phenomena, which influence protein phosphorylation changes. Such changes have been associated with a molecular switch in the pathways that regulate cell proliferation and carcinogenesis. In this thesis, T cell response in extreme conditions was evaluated to better clarify the chemical complexity of the lymphocytic proteome. Particularly, I focused on the Spleen Tyrosine Kinase family components, Syk and Zap-70, already known in the literature for their behaviour in pathological states and for their possible role in the treatment of some forms of leukemia and lymphoma. Western blot analysis of total proteins of T cells treated in different ways showed a strong phosphorylative response and a consistent expression of Syk kinase

Evaluation of Staging Systems for Cancer of the Nasal Vestibule

Squamous cell carcinoma of the nasal vestibule is reported to account for less than one percent of all head and neck malignancies. It lacks a designated WHO ICD-O topography code, and multiple systems are available for the staging of this disease, which results in unwanted variability and the subsequent poor reliability of data. The aim of this study was to evaluate the currently available staging systems for cancer of the nasal vestibule, including the recently introduced classification by Bussu et al., which built on Wang's original concept but with clearer anatomical cutoffs. Different staging systems for cancer of the nasal vestibule (UICC nasal cavity, UICC skin cancer of the head and neck, Wang and Bussu et al.) were evaluated via a retrospective analysis of 148 patients. The staging system, per Bussu et al., had the most balanced allocation of patients among the stages. When using the Wang classification as a reference, stage migration occurred less frequently with the Bussu classification. The widespread adoption of a single staging system, as well as the introduction of a designated topography code for cancer of the nasal vestibule, could lead to more uniformity in data reporting and improve an understanding of the incidence and disease outcome. The newly proposed carcinoma of the nasal vestibule classification by Bussu et al. has the potential to improve the staging and allocation among stages. Further analysis of survival data is needed to assess which classification system is best suited for nasal vestibule carcinoma

Signal transduction in primary human T lymphocytes in altered gravity - results of the MASER-12 suborbital space flight mission

We investigated the influence of altered gravity on key proteins of T cell activation during the MASER-12 ballistic suborbital rocket mission of the European Space Agency (ESA) and the Swedish Space Cooperation (SSC) at ESRANGE Space Center (Kiruna, Sweden). We quantified components of the T cell receptor, the membrane proximal signaling, MAPK-signaling, IL-2R, histone modifications and the cytoskeleton in non-activated and in ConA/CD28-activated primary human T lymphocytes. The hypergravity phase during the launch resulted in a downregulation of the IL-2 and CD3 receptor and reduction of tyrosine phosphorylation, p44/42-MAPK phosphorylation and histone H3 acetylation, whereas LAT phosphorylation was increased. Compared to the baseline situation at the point of entry into the microgravity phase, CD3 and IL-2 receptor expression at the surface of non-activated T cells were reduced after 6 min microgravity. Importantly, p44/42-MAPK-phosphorylation was also reduced after 6 min microgravity compared to the 1g ground controls, but also in direct comparison between the in-flight μg and the 1g group. In activated T cells, the reduced CD3 and IL-2 receptor expression at the baseline situation recovered significantly during in-flight 1g conditions, but not during microgravity conditions. Beta-tubulin increased significantly after onset of microgravity until the end of the microgravity phase, but not in the in-flight 1g condition. This study suggests that key proteins of T cell signal modules are not severely disturbed in microgravity. Instead, it can be supposed that the strong T cell inhibiting signal occurs downstream from membrane proximal signaling, such as at the transcriptional level as described recently. However, the MASER-12 experiment could identify signal molecules, which are sensitive to altered gravity, and indicates that gravity is obviously not only a requirement for transcriptional processes as described before, but also for specific phosphorylation / dephosphorylation of signal molecules and surface receptor dynamics

Accuracy of p16 IHC in Classifying HPV-Driven OPSCC in Different Populations

High-risk human papillomavirus (HPV) infection is a defined etiopathogenetic factor in oropharyngeal carcinogenesis with a clear prognostic value. The P16 IHC (immunohistochemistry) is a widely accepted marker for HPV-driven carcinogenesis in oropharyngeal squamous cell carcinoma (OPSCC); in the present paper, we discuss its reliability as a standalone marker in different populations. The literature suggests that rates of p16 IHC false positive results are inversely correlated with the prevalence of HPV-driven carcinogenesis in a population. We propose a formula that can calculate such a false positive rate while knowing the real prevalence of HPV-driven OPSCCs in a given population. As it has been demonstrated that p16 positive/HPV negative cases (i.e., false positives at p16 IHC) have the same prognosis as p16 negative OPSCC, we conclude that despite the valuable prognostic value of p16 IHC, relying only on a p16 IHC positive result to recommend treatment de-intensification could be risky. For this aim, confirmation with an HPV nucleic acid detection system, especially in areas with a low prevalence of HPV-related OPSCCs, should be pursued. Simple summary p16 IHC is the HPV detection method suggested by the current version of the TNM (AJCC 8th edition) for oropharyngeal squamocellular carcinoma. However, its reliability has been extensively discussed, and its applicability in every context, especially the enrollment of patients in de-intensification protocols, is debatable. Here, we discuss its limits, especially in populations with a low prevalence of HPV-driven oropharyngeal squamocellular carcinoma, and suggest the possible actions to be taken to overcome such limitations

Immunomodulatory properties of carbon nanotubes are able to compensate immune function dysregulation caused by microgravity conditions

Spaceflights lead to dysregulation of the immune cell functionality affecting the expression of activation markers and cytokine production. Short oxidized multi-walled carbon nanotubes functionalized by 1,3-dipolar cycloaddition have been reported to activate immune cells. In this Communication we have performed surface marker assays and multiplex ELISA on primary monocytes and T cells under microgravity. We have discovered that carbon nanotubes, through their immunostimulatory properties, are able to fight spaceflight immune system dysregulations

Low Prevalence of HPV Related Oropharyngeal Carcinogenesis in Northern Sardinia

HPV infection is a clear etiopathogenetic factor in oropharyngeal carcinogenesis and is associated with a markedly better prognosis than in smoking- and alcohol-associated cases, as specified by AJCC classification. The aim of the present work is to evaluate the prevalence of HPV-induced OPSCC in an insular area in the Mediterranean and to assess the reliability of p16 IHC (immunohistochemistry) alone, as accepted by AJCC, in the diagnosis of HPV-driven carcinogenesis in such a setting. All patients with OPSCC consecutively managed by the referral center in North Sardinia of head and neck tumor board of AOU Sassari, were recruited. Diagnosis of HPV-related OPCSS was carried out combining p16 IHC and DNA testing on FFPE samples and compared with the results of p16 IHC alone. Roughly 14% (9/62) of cases were positive for HPV-DNA and p16 IHC. Three more cases showed overexpression of p16, which has a 100% sensitivity, but only 75% specificity as standalone method for diagnosing HPV-driven carcinogenesis. The Cohen’s kappa coefficient of p16 IHC alone is 0.83 (excellent). However, if HPV-driven carcinogenesis diagnosed by p16 IHC alone was considered the criterion for treatment deintensification, 25% of p16 positive cases would have been wrongly submitted to deintensified treatment for tumors as aggressive as a p16 negative OPSCC. The currently accepted standard by AJCC (p16 IHC alone) harbors a high rate of false positive results, which appears risky for recommending treatment deintensification, and for this aim, in areas with a low prevalence of HPV-related OPSCC, it should be confirmed with HPV nucleic acid detection

T cell tyrosine phosphorylation response to transient redox stress

Reactive Oxygen Species (ROS) are crucial to multiple biological processes involved in the pathophysiology of inflammation, and are also involved in redox signaling responses. Although previous reports have described an association between oxidative events and the modulation of innate immunity, a role for redox signaling in T cell mediated adaptive immunity has not been described yet. This work aims at assessing if T cells can sense redox stress through protein sulfhydryl oxidation and respond with tyrosine phosphorylation changes. Our data show that Jurkat T cells respond to –SH group oxidation with specific tyrosine phosphorylation events. The release of T cell cytokines TNF, IFNγ and IL2 as well as the expression of a number of receptors are affected by those changes. Additionally, experiments with spleen tyrosine kinase (Syk) inhibitors showed a major involvement of Syk in these responses. The experiments described herein show a link between cysteine oxidation and tyrosine phosphorylation changes in T cells, as well as a novel mechanism by which Syk inhibitors exert their anti-inflammatory activity through the inhibition of a response initiated by ROS

Reliability of a Multidisciplinary Multiparametric Approach in the Surgical Planning of Laryngeal Squamous Cell Carcinomas: A Retrospective Observational Study

(1) Background: Endoscopy and morphological imaging are the mainstay of the diagnostic work up of laryngeal squamous cell carcinomas (LSCCs), which can be integrated in a multidisciplinary discussion to obtain a shared pretreatment staging. (2) Methods: A retrospective evaluation of patients, managed at a tertiary university hospital in Italy and submitted to major laryngeal surgery, has been performed. Four different stagings have been defined and compared: epTN (based on endoscopy and physical ENT examination); radTN (based on CT scan); cTN (based on multidisciplinary integration of the two above); pTN based on pathology on surgical samples. Oncological outcomes have been assessed. (3) Results: Three-year relapse free and disease specific survival were 88% and 92.5%, respectively, without significant differences between partial surgeries (n = 13) and total laryngectomies (n = 32). As for the pretreatment staging, and in particular the T classification, the cTN has been revealed as more reliable than epTN and radTN alone in predicting the final pT (Cohen kappa coefficient: 0.7 for cT, 0.44 for radT, 0.32 for epT). In the partial surgery group, we did not record any positive margin nor local recurrence, with a 100% overall and disease-specific survival. (4) Conclusions: The multidisciplinary approach is fundamental in the definition of the primary lesion in LSCC, in particular in order to safely perform surgical preservation of laryngeal function, which is associated with a higher laryngectomy-free survival than irradiation but to a lower salvageability in case of recurrence

New standards for the management of nose vestibule malignancies

Background: Nasal vestibule squamous cell carcinoma (NVSCC) is an ill-defined underestimated condition. Aim/objective: To define the current standard of care. Material and methods: We review recent acquisitions concerning clinical features and therapeutic approaches. Results: The current AJCC staging system, which attributes to nasal vestibule the same topographic code as nasal cavity proper and the same T-classification criteria as ethmoid, appears inadequate.As for treatment of primary lesions without bone invasion, current evidence suggests that brachytherapy is at least equivalent to surgery and superior to external beams in terms of oncological outcomes, and superior to both modalities in terms of cosmesis and function. Conclusions: As for classification and staging, the nasal vestibule should be defined as a subsite of the nose and paranasal sinuses, distinct from the 'nasal cavity proper and ethmoid', with specific topographic code and T-classification criteria. This will improve the assessment of prognosis and prevalence, underestimated also because of misdiagnosis with skin cancers.Secondly, brachytherapy should become the new standard for the treatment of primary lesions without bone invasion. To optimize the advantages of brachytherapy, we propose novel anatomic criteria for the implantation. Significance: Increasing evidence supports a paradigm shift in staging and treatment of NVSCC

Audiological Risk Factors, Referral Rates and Dropouts: 9 Years of Universal Newborn Hearing Screening in North Sardinia

Background: Objectives of the present work were to analyze the prevalence of hearing loss in our population of screened newborns during the first 9 years of the universal newborn hearing screening (UNHS) program at University Hospital Sassari (Italy) (AOU Sassari), to analyze the risk factors involved, and to analyze our effectiveness in terms of referral rates and dropout rates. Methods: Monocentric retrospective study whose target population included all the newborns born or referred to our hospital between 2011 and 2019. Results: From 2011 to 2019, a total of 11,688 babies were enrolled in our screening program. In total, 3.9‰ of wellborn babies and 3.58% of neonatal intensive care unit (NICU) babies had some degree of hearing loss. The most frequently observed risk factors among non-NICU babies were family history of hearing loss (3.34%) and craniofacial anomalies (0.16%), among NICU babies were low birth weight (54.91%) and prematurity (24.33%). In the multivariate analysis, family history of hearing loss (p < 0.001), NICU (p < 0.001), craniofacial anomalies (p < 0.001), low birth weight (<1500 g) (p = 0.04) and HIV (p = 0.03) were confirmed as risk factors. Conclusions: Our data are largely consistent with the literature and most results were expected, one relevant exception being the possible role of NICU as a confounding factor and the limited number of risk factors confirmed in the multivariate analysis