The main risk factor for skin cancer is ultraviolet (UV) exposure, which causes DNA damage. Cells respond to UV-induced DNA damage by activating the intra-S-phase checkpoint, which prevents replication fork collapse, late origin firing and stabilizes fragile sites. Recently, the 54-kDa multifunctional protein NONO was found to be involved in the non-homologous end-joining DNA repair process and in poly ADP-ribose polymerase 1 activation. Interestingly, NONO is mutated in several tumour types and emerged as a crucial factor underlying both melanoma development and progression. Therefore, we set out to evaluate whether NONO could be involved in the DNA-damage response to UV radiations. We generated NONO-silenced HeLa cell clones and found that lack of NONO decreased cell growth rate. Then, we challenged NONO-silenced cells with exposure to UV radiations and found that NONO-silenced cells, compared with control cells, continued to synthesize DNA, failed to block new origin firing and impaired CHK1S345 phosphorylation showing a defective checkpoint activation. Consistently, NONO is present at the sites of UV-induced DNA damage where it localizes to RAD9 foci. To position NONO in the DNA-damage response cascade, we analysed the loading onto chromatin of various intra-S-phase checkpoint mediators and found that NONO favours the loading of topoisomerase II-binding protein 1 acting upstream of the ATM and Rad3-related kinase activity. Strikingly, re-expression of NONO, through an sh-resistant mRNA, rescued CHK1S345 phosphorylation in NONO-silenced cells. Interestingly, NONO silencing affected cell response to UV radiations also in a melanoma cell line. Overall, our data uncover a new role for NONO in mediating the cellular response to UV-induced DNA damage.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) belongs to the Beta-coronavirus genus. It is 96.2% homologous to bat CoV RaTG13 and 88% homologous to two bat SARS-like coronaviruses. SARS-CoV-2 is the infectious agent responsible for the coronavirus disease (COVID-19), which was first reported in the Hubei province of Wuhan, China, at the beginning of December 2019. Human transmission from COVID-19 patients or incubation carriers occurs via coughing, sneezing, speaking, discharge from the nose, or fecal contamination. Various strains of the virus have been reported around the world, with different virulence and behavior. In addition, SARS-CoV-2 shares certain epitopes with some taxonomically related viruses, with tropism for the most common synanthropic animals. By elucidating the immunological properties of the circulating SARS-CoV-2, a partial protection due to human–animal interactions could be supposed in some situations. In addition, differential epitopes could be used for the differential diagnosis of SARS-CoV-2 infection. There have been cases of transmission from people with COVID-19 to pets such as cats and dogs. In addition, wild felines were infected. All These animals were either asymptomatic or mildly symptomatic and recovered spontaneously. Experimental studies showed cats and ferrets to be more susceptible to COVID-19. COVID-19 positive dogs and felines do not transmit the infection to humans. In contrast, minks at farms were severely infected from people with COVID-19. A SARS-Cov-2 variant in the Danish farmed mink that had been previously infected by COVID-19 positive workers, spread to mink workers causing the first case of animal-to-human infection transmission that causes a moderate decreased sensitivity to neutralizing antibodies. Thus, more investigations are necessary. It remains important to understand the risk that people with COVID-19 pose to their pets, as well as wild or farm animals so effective recommendations and risk management measures against COVID-19 can be made. A One Health unit that facilitates collaboration between public health and veterinary services is recommended.

The retinoblastoma (RB) protein family includes RB1/p105, RBL1/p107, and RBL2/p130, which are key factors in cell-cycle regulation and stand at the crossroads of multiple pathways dictating cell fate decisions. The role of RB proteins in apoptosis is controversial because they can inhibit or promote apoptosis depending on the context, on the apoptotic stimuli and on their intrinsic status, impacting on the response to antitumoral treatments. Here we identified RBL2/p130 as a direct substrate of the AKT kinase, a key antiapoptotic factor hyperactive in multiple cancer types. We showed that RBL2/p130 and AKT1 physically interact and AKT phosphorylates RBL2/p130 Ser941, located in the pocket domain, but not when this residue is mutated into Ala. We found that pharmacological inhibition of AKT, through the highly selective AKT inhibitor VIII (AKTiVIII), impairs RBL2/p130 Ser941 phosphorylation and increases RBL2/p130 stability, mRNA expression and nuclear levels in both lung cancer and mesothelioma cell lines, mirroring the more extensively studied effects on the p27 cell-cycle inhibitor. Consistently, AKT inhibition reduced cell viability, induced cell accumulation in G0/G1, and triggered apoptosis, which proved to be largely dependent on RBL2/p130 itself, as shown upon RBL2/p130 silencing. AKT inhibition induced RBL2/p130-dependent apoptosis also in HEK-293 cells, in which re-expression of a short hairpin-resistant RBL2/p130 was able to rescue AKTiVIII-induced apoptosis upon RBL2/p130 silencing. Our data also showed that the combination of AKT and cyclin-dependent kinases (CDK) inhibitors, which converge on the re-activation of RBL2/p130 antitumoral potential, could be a promising anticancer strategy.

Malignant pleural mesothelioma (MPM) is an aggressive cancer, related to asbestos exposure, which has a dismal prognosis. MPM diagnosis is late and often challenging, suggesting the need to identify more reliable molecular biomarkers. Here, we set out to identify differentially expressed miRNAs in epithelioid, biphasic, and sarcomatoid MPMs versus normal mesothelium and explored specific miRNA contribution to mesothelial tumorigenesis. We screened an LNA™-based miRNA-microrray with 14 formalin-fixed paraffin-embedded (FFPE) MPMs and 6 normal controls. Through real-time qRT-PCR we extended the analysis of a miRNA subset and further investigated miR-320a role through state-of-the-art techniques. We identified 16 upregulated and 32 downregulated miRNAs in MPMs versus normal tissue, including the previously identified potential biomarkers miR-21, miR-126, miR-143, miR-145. We showed in an extended series that miR-145, miR-10b, and miR-320a levels can discriminate tumor versus controls with high specificity and sensitivity. We focused on miR-320a because other family members were found downregulated in MPMs. However, stable miR-320a ectopic expression induced higher proliferation and migration ability, whereas miR-320a silencing reduced these processes, not supporting a classic tumor-suppressor role in MPM cell lines. Among putative targets, we found that miR-320a binds the 3′-UTR of the immune inhibitory receptor ligand PDL1 and, consistently, miR-320a modulation affects PDL1 levels in MPM cells. Finally, we showed that p53 over-expression induces the upregulation of miR-320a, along with miR-200a and miR-34a, both known to target PDL1, and reduces PDL1 levels in MPM cells. Our data suggest that PDL1 expression might be due to a defective p53-regulated miRNA response, which could contribute to MPM immune evasion or tumorigenesis through tumor-intrinsic roles.

The antigen-specific primary activation of CD4 ؉ T cells was studied in vivo by adoptive transfer of ovalbumin-specific transgenic T cells (KJ1-26 ؉ CD4 ؉ ) following intranasal immunization with recombinant Streptococcus gordonii. A strain of S. gordonii expressing on its surface a model vaccine antigen fused to the ovalbumin (OVA) peptide from position 323 to 339 was constructed and used to study the OVA-specific T-cell activation in nasal mucosa-associated lymphoid tissue (NALT), lymph nodes, and spleens of mice immunized by the intranasal route. The recombinant strain, but not the wild type, activated the OVA-specific CD4 ؉ T-cell population in the NALT (89% of KJ1-26 ؉ CD4 ؉ T cells) just 3 days following immunization. In the cervical lymph nodes and in the spleen, the percentage of proliferating cells was initially low, but it reached the peak of activation at day 5 (90%). This antigen-specific clonal expansion of KJ1-26 ؉ CD4 ؉ T cells after intranasal immunization was obtained with live and inactivated recombinant bacteria, and it indicates that the NALT is the site of antigen-specific T-cell priming.