Mithramycin delivery systems to develop effective therapies in sarcomas.

BACKGROUND: Sarcomas comprise a group of aggressive malignancies with very little treatment options beyond standard chemotherapy. Reposition of approved drugs represents an attractive approach to identify effective therapeutic compounds. One example is mithramycin (MTM), a natural antibiotic which has demonstrated a strong antitumour activity in several tumour types, including sarcomas. However, its widespread use in the clinic was limited by its poor toxicity profile. RESULTS: In order to improve the therapeutic index of MTM, we have loaded MTM into newly developed nanocarrier formulations. First, polylactide (PLA) polymeric nanoparticles (NPs) were generated by nanoprecipitation. Also, liposomes (LIP) were prepared by ethanol injection and evaporation solvent method. Finally, MTM-loaded hydrogels (HG) were obtained by passive loading using a urea derivative non-peptidic hydrogelator. MTM-loaded NPs and LIP display optimal hydrodynamic radii between 80 and 105 nm with a very low polydispersity index (PdI) and encapsulation efficiencies (EE) of 92 and 30%, respectively. All formulations show a high stability and different release rates ranging from a fast release in HG (100% after 30 min) to more sustained release from NPs (100% after 24 h) and LIP (40% after 48 h). In vitro assays confirmed that all assayed MTM formulations retain the cytotoxic, anti-invasive and anti-stemness potential of free MTM in models of myxoid liposarcoma, undifferentiated pleomorphic sarcoma and chondrosarcoma. In addition, whole genome transcriptomic analysis evidenced the ability of MTM, both free and encapsulated, to act as a multi-repressor of several tumour-promoting pathways at once. Importantly, the treatment of mice bearing sarcoma xenografts showed that encapsulated MTM exhibited enhanced therapeutic effects and was better tolerated than free MTM. CONCLUSIONS: Overall, these novel formulations may represent an efficient and safer MTM-delivering alternative for sarcoma treatment.

Lectin-Like Transcript 1 (LLT1) Checkpoint: A Novel Independent Prognostic Factor in HPV-Negative Oropharyngeal Squamous Cell Carcinoma.

Lectin-like transcript 1 (LLT1) expression by tumor cells contributes to immune evasion, thereby emerging as a natural killer (NK) cell-mediated immunotherapeutic target. This study is the first to investigate LLT1 expression (encoded by CLEC2D gene) in head and neck cancers to ascertain its impact on patient prognosis. LLT1 expression was analyzed by immunohistochemistry in a homogeneous cohort of human papillomavirus (HPV)-negative oropharyngeal squamous cell carcinomas (OPSCC), and correlated with clinical data. Results were further validated using transcriptomic data from the TCGA database. Tumoral LLT1 expression was detected in 190/221 (86%) OPSCC specimens, whereas normal pharyngeal epithelium was negative. Patients harboring LLT1-positive tumors showed significantly lower disease-specific (DSS) and overall survival (OS) (p = 0.049 and p = 0.036, respectively, log-rank test). High density of LLT1-positive tumor-infiltrating lymphocytes (TIL) was also frequently detected in 160 (73%) OPSCC samples, and significantly associated with better DSS and OS (p < 0.001 and p = 0.007, respectively). Multivariate Cox analysis further revealed that tumoral LLT1 expression and infiltration of LLT1-positive TIL were independent prognostic factors for DSS and OS. CLEC2D mRNA levels are also significantly increased in primary tumors compared to normal tissue. Strikingly, the prognostic impact of CLEC2D mRNA levels varied depending on HPV status in OPSCC, and among distinct cancer types. CLEC2D expression was significantly correlated with NK cell infiltration using the MCP-counter model. These findings uncover LLT1/CLEC2D as an independent prognostic factor in HPV-negative OPSCC, and a potential novel target for immunotherapy.

Correlation of Micro-Computed Tomography Assessment of Valvular Mineralisation with Histopathological and Immunohistochemical Features of Calcific Aortic Valve Disease.

Aortic valve stenosis is a serious disease with increasing prevalence in developed countries. Research aimed at uncovering the molecular mechanisms behind its main cause, aortic valve calcification, is thus crucial for the development of future therapies. It is frequently difficult to measure the extent of mineralisation in soft tissues and some methods require the destruction of the sample. Micro-computed tomography (µCT), a non-destructive technique, was used to quantify the density and volume of calcium deposits on cusps from 57 explanted aortic valves. Conventional and immunostaining techniques were used to characterise valve tissue degeneration and the inflammatory and osteogenic stage with several markers. Although most of the analysed cusps came from severe stenosis patients, the µCT parameter bone volume/tissue volume ratio distinguished several degrees of mineralisation that correlated with the degree of structural change in the tissue and the amount of macrophage infiltration as determined by CD68 immunohistochemistry. Interestingly, exosomal markers CD63 and Alix co-localised with macrophage infiltration surrounding calcium deposits, suggesting that those vesicles could be produced at least in part by these immune cells. In conclusion, we have shown that the ex vivo assessment of aortic valve mineralisation with µCT reflects the molecular and cellular changes in pathological valves during progression towards stenosis. Thus, our results give additional validity to quantitative µCT as a convenient laboratory tool for basic research on this type of cardiovascular calcification.

Tumor programmed cell death ligand 1 expression correlates with nodal metastasis in patients with cutaneous squamous cell carcinoma of the head and neck.

BACKGROUND: Binding of tumor-expressed programmed cell death ligand 1 (PD-L1) to the programmed cell death 1 (PD-1) surface receptor blocks T-cell activation thereby leading to immune evasion. Tumor PD-L1 expression has been associated with poor outcome in a wide variety of cancers; however, data in cutaneous squamous cell carcinoma (cSCC) are scarce and conflicting. OBJECTIVE: To investigate the relationship of tumor PD-L1 expression with the clinicopathologic features and prognosis of cSCC. METHODS: PD-L1 expression was analyzed by immunohistochemistry on paraffin-embedded tissue samples from 100 patients with cSCC. Cumulative/dynamic receiver operating characteristic curve was used to determine the optimal PD-L1 threshold. Kaplan-Meier estimators and Cox proportional hazards regression models were also used. RESULTS: On the basis of cumulative/dynamic receiver operating characteristic curves, we defined the cut-off score for PD-L1 expression as ≥25% of tumor cells positively stained. PD-L1 expression was a significant risk factor for nodal metastasis with crude and adjusted hazard ratios of 3.39 (1.71-6.65) and 6.54 (2.28-18.78), respectively. LIMITATIONS: This is a retrospective study limited to cSCC of the head and neck. CONCLUSION: These findings indicate that tumor PD-L1 expression predicts increased risk for nodal metastasis in patients with cSCC.

Prognostic factors and survival study in high-grade glioma in the elderly.

Background Glioblastoma multiforme (GBM) is the most common and malignant primary brain tumour in adults. Due to the ageing of the population, diagnosis in the elderly is becoming more common. The aim of this study was to analyse different combinations of treatments and to identify preoperative factors, including O6-methylguanine-DNA methyltransferase status, that may be associated with decreased survival among patients older than 70 years. Methods and materials We retrospectively included all patients over 70 years of age, who underwent surgery at the Department of Neurosurgery (HUCA and HUMV) and were diagnosed of GBM by pathological criteria from January 2007 to September 2014. Results Eighty-one patients were analysed, whose mean age was 75 (SD 4) and 48 were male. Karnofsky performance status (KPS) was over 70 in 61 patients and 38.3% presented with motor deficit. Sixty-three patients underwent resection, and 18 had only a diagnostic biopsy. The complication rate was 17.28% and mortality rate was 7.4%. Survival was increased in patients who received radiotherapy (n = 41) or additional chemotherapy (n = 26) (p < 0.001). KPS < 70 was an independent factor associated with low-rate survival. Patients with optimal treatment had a median survival of 8 months compared to patients with suboptimal treatment who had a median survival of 4 months (p < 0.001). Conclusions This study suggests that KPS is the most important preoperative prognostic factor. Maximal safe resection followed by radical radiotherapy and temozolomide might be the optimal treatment of choice since glioblastoma-diagnosed patients over 70 years of age showed a statistically significant survival benefit.