MiRNA Signatures Related to Invasiveness and Recurrence in Patients With Non-Functioning Pituitary Neuroendocrine Tumors

PURPOSE

This preliminary study aimed to analyze and identify differentially expressed miRNAs in Bulgarian patients with non-functioning pituitary neuroendocrine tumors (NFPitNET). The relationship between deregulated miRNAs and tumor invasiveness, recurrence, and size was determined.

METHODS

Twenty patients with NFPitNET were selected and fresh pituitary tumor tissues were collected. RNA containing miRNAs were isolated using miRNAeasy mini kit and analyzed by quantitative real-time polymerase chain reaction (PCR) using LNA miRNA Cancer-Focus PCR Panel (Qiagen).

RESULTS

Three miRNAs (miR-210-3p, miR-149-3p, and miR-29b-3p) were deregulated in invasive compared to non-invasive NFPitNETs. Differential expression of four-miRNA signatures - miRNA-17, miR-19, miR-106a, and miR-20, correlated with patient recurrence.

CONCLUSION

This prospective pilot study selected a unique miRNA expression profile, that correlates with invasiveness and recurrence in non-functioning pituitary neuroendocrine tumors. Moreover, some of the selected miRNAs are reported for the first time in patients with this disease, shedding light on the molecular mechanisms involved in pituitary pathogenesis. The identified miRNAs demonstrate potential as biomarkers, deserving further investigation in a larger cohort to validate their clinical applicability.

miRNAs and related genetic biomarkers according to the WHO glioma classification: From diagnosis to future therapeutic targets

In the 2021 WHO classification of Tumors of the Central Nervous System, additional molecular characteristics have been included, defining the following adult-type diffuse glioma entities: Astrocytoma IDH-mutant, Oligodendroglioma IDH-mutant and 1p/19q-codeleted, and Glioblastoma IDH-wildtype. Despite advances in genetic analysis, precision oncology, and targeted therapy, malignant adult-type diffuse gliomas remain "hard-to-treat tumors", indicating an urgent need for better diagnostic and therapeutic strategies. In the last decades, miRNA analysis has been a hotspot for researching and developing diagnostic, prognostic, and predictive biomarkers for various disorders, including brain cancer. Scientific interest has recently been directed towards therapeutic applications of miRNAs, with encouraging results. Databases such as NCBI, PubMed, and Medline were searched for a selection of articles reporting the relationship between deregulated miRNAs and genetic aberrations used in the latest WHO CNS classification. The current review discussed the recommended molecular biomarkers and genetic aberrations based on the 2021 WHO classification in adult-type diffuse gliomas, along with associated deregulated miRNAs. Additionally, the study highlights miRNA-based treatment advancements in adults with gliomas.

Synergistic inhibition of influenza A virus replication by a plant polyphenol-rich extract and epsilon-aminocaproic acid in vitro and in vivo

A combined antiviral effect of a polyphenol-rich extract of the medicinal plant Geranium sanguineum L. (PC) and a protease inhibitor, epsilon-aminocaproic acid (ACA) was examined in Influenza A virus (IAV)-infected MDCK cell cultures and mice. Synergistic, antagonistic, or indifferent antiviral effects were distinguished on the basis of virus yields, namely fractional yields of individual compounds and yields of both compounds in combination. Combinations of PC and ACA in particular concentrations proved synergistic in the inhibition of virus replication in MDCK cells and in protection of mice against virus infection as determined by virus titers, lung weight, mean survival time (MST), mortality rate, and protection rate (PR). Following the application of a combination of PC and ACA to the virus-infected mice, the levels of the lung protease and protease-inhibitory activity, which were increased due to the virus infection, were brought to normal. These results demonstrate the rationale for a combined application of viral inhibitors with different modes of action to the treatment of IAV infection, in particular PC as a natural inhibitor of early viral transcription and translation and ACA as a synthetic inhibitor of cellular proteases.

KEYWORDS

Influenza A virus; antiviral effect; synergism; plant polyphenol extract; epsilon-aminocaproic acid; protease inhibitors.

Limbal explants from cryopreserved cadaver human corneas. Immunofluorescence and light microscopy of epithelial cells growing in culture

The aim of the present study was to determine whether human cadaver corneas, that were subject to cryopreservation, would be a source of migrating epithelial cells in vitro and what kind of morphological features these cells possess. Limbal explant culture was used for expanding the epithelial cells. Non-quantitative light microscopical examinations of the cultures within a period of 28 days were carried out. The phenotype of cultured cells, particularly of the presumed adult stem cell population, was examined by indirect fluorescent immunostaining using antibodies against corneal stem cell associated markers p63 and vimentin. The effectiveness of the freezing-thawing protocol was confirmed by cultivation of limbal explants taken from non-cryopreserved cadaver corneoscleral rims. The result clearly showed that limbal tissue, subjected to cryopreservation and long lasting (up to 12 months) storage in liquid nitrogen, retains the capacity to be source of migrating and proliferating epithelial cells in vitro including the presumed adult stem cells and transient amplifying cells.

Saponins from Tribulus terrestris L are less toxic for normal human fibroblasts than for many cancer lines: influence on apoptosis and proliferation

The objective of the study was to explore the influence of saponins derived from Tribulus terrestris L. (TT) on normal human skin fibroblasts and to compare it with their anticancer properties. In this study, [3H]thymidine incorporation and MTT to assess cell proliferation and viability, respectively, and immunoblotting and HPLC analysis to explore intracellular signal transduction pathways have been used. We found that TT caused a dose-dependent decrease in [3H]thymidine incorporation into the DNA of treated fibroblast compared to the untreated controls. Viability of treated cells remained within the control levels with treatment of up to 5 micro g TT/ml medium. It was significantly depressed with incubation in > or =6 micro g TT/ml medium with an IC50 of 12.6 micro g TT/ml of cultivating media. ERK1/2 was significantly dephosphorylated at 5 mins of incubation with TT until the 48th hour, when phosphorylation slightly recovered, but was still below the control levels. In contrast, p38 and JNK phosphorylation was positively influenced, with peaks at 1 hr and 24 hrs of incubation respectively. Phosphorylation/dephosphorylation events of SAPK/MAPK clearly correlated with Mkp-1 induction. Procaspase 3 was activated after 5 mins of incubation and coincided with a rapid actin cleavage. There was a significant decrease of putrescine concentration and a concomitant increase of spermidine and spermine at 2 mins of treatment. According to our results, TT is less toxic for normal human skin fibroblasts in comparison to many cancer lines investigated in previous studies. The molecular mechanism of this cytotoxicity involves up- and downregulation of polyamines' homeostasis, suppression of proliferation, and induction of apoptosis. Further research in this field using animal models would help to explore and interpret the potential properties of TT as an anticancer supplement.

Reduction of nonlinear dynamic systems with an application to signal transduction pathways

Mathematical modelling of kinetic processes with different time scales allows a reduction of the governing equations using quasi-steady-state approximations (QSSA). A QSSA theorem is applied to a mathematical model of the influence that Raf kinase inhibitor protein (RKIP) has on the ERK signalling pathway. On the basis of previously published parameter values, the system of 11 ordinary differential equations is rewritten in a form suitable for model reduction. In accordance with the terminology of the QSSA theorem, it is established that four of the protein and protein-complex concentrations are 'fast varying', such that the corresponding kinetic equations form an attached system. Another concentration is 'medium varying' such that the corresponding equation is reduced with respect to the four fast ones. The other six concentrations are 'slow varying', which means the corresponding kinetic equations also present a reduced system with respect to the others. Analytical solutions, relating the steady-state values of the fast varying protein concentrations and the slow varying ones, are derived and interpreted as restrictions on the regulatory role of RKIP on ERK-pathway.

The penguin feathers as bioindicator of Antarctica environmental state

Concentrations of biogenic and toxic elements (Na, K, Mg, Ca, P, S, Fe, Cu, Zn, Co, Mn, Se, Ni, Sr, Al, Cd, Pb, As) were determined for the first time in feathers of gentoo penguin (Pygoscelis papua) and chinstrap penguin (Pygoscelis antarctica) from Antarctica. A comparison of element levels was performed among these species in years 2002-2003. Penguins molt annually and this fact allows defining precisely the concentrations of accumulated toxic elements and heavy metals in plumage every year. A continual environmental biomonitoring could establish a possible trend to contamination of the Antarctica sea zones. The penguin feather is an excellent subject for monitoring because penguins have long life span, permanent ecological niche and dominate the aviafauna in Antarctica. Because of its remoteness, Antarctica is believed to be unpolluted. The relatively elevated levels of Cd established are due to the Cd-enrichment of the Antarctic marine food chain. Because of great bioaccumulation of lead in feathers, the concentration of Pb in penguin feather was higher (4-8 times) compared to that of Cd. In both penguin species the levels of Zn were 1.9 times higher than respective Fe levels. The concentrations of most of the investigated elements were significantly higher in P. papua than in P. antarctica and this probably could be explained by the different diet and feeding habit of these species.

Integrity of endothelium in cryopreserved human cornea

The aim of the present study was to elaborate an optimal method for cryopreservation of human donor cornea for transplantation and to follow the morphological changes in the structure of the endothelial cell layer using scanning electron microscopy (SEM). Sixteen groups, with four donor cornea each, were cryopreserved at cooling rates of 1 degree C per min and 5 degree C per min. Four cryoprotectants (glycerol, dimethyl sulfoxide, 1,2-propanediol, polyethylene glycol-400) in two concentrations (5% and 10% v/v) were prepared on the bases of medium Optisol GS supplied with 20% v/v human serum albumin. Four additional human cornea were used as controls. Endothelial cell recovery of the cornea after thawing and 24 hours culture, was calculated as a percent of the preserved recovered cells. Sufficient recovery of the endothelial cell layer, making the cornea suitable for transplantation was obtained using the cryoprotectants dimethyl sulfoxide and especially polyethylene glycol-400.

Inhibition of Streptococcus mutans adherence to saliva-coated hydroxyapatite by human secretory immunoglobulin A (S-IgA) antibodies to cell surface protein antigen I/II: reversal by IgA1 protease cleavage

The effect of human secretory immunoglobulin A (S-IgA) and serum antibodies to surface protein antigen (Ag) I/II on the adherence of Ag I/II-bearing Streptococcus mutans and of free Ag I/II to saliva-coated hydroxyapatite (SHA) was investigated. The inhibition by S-IgA of binding of both S. mutans and free Ag I/II to SHA was dependent on antibody to Ag I/II. Essentially no difference was found between S-IgA1 and S-IgA2 with respect to antibody-dependent inhibition of Ag I/II binding to SHA, but S-IgA1 inhibited S. mutans adherence more effectively than did either serum immunoglobulin A1 (IgA1) or IgG antibodies. The antiadherence effect of S-IgA was abrogated after cleavage by IgA1 protease. Purified Fab alpha fragments containing Ag I/II-binding activity enhanced the binding of free Ag I/II to SHA and showed greater binding to SHA than did intact S-IgA1. Despite its relative inability to interact with precoated SHA, S-IgA1 containing antibody to Ag I/II was readily incorporated into the salivary pellicle during coating, but this did not promote Ag I/II binding. These data suggest that S-IgA antibodies can inhibit the initial adherence of S. mutans to salivary pellicle-coated tooth surfaces in an adhesin-specific fashion, but the presence in the oral cavity of bacterial IgA1 proteases would potentially interfere with this antiadherence mechanism.

Kinetics of MHC class II and transferrin receptor expression by colostral cells stimulated in vitro with concanavalin A and myelin basic protein

The colostral cells, regarded generally as being protective, have been shown to differ in a number of membrane properties (rosetting, adherence, mobility) from the corresponding peripheral blood mononuclear cells. After in vitro stimulation with Con A or MBP 50% to 70% of the human colostral cells appeared HLA-DR positive at the first 24 h of culturing. The CD71 expression reached a maximum on culture days 2-3 coinciding with the maximal proliferative response. With regard to the phenotypic characteristics and their kinetics, the human colostral cells did not show significant differences from the peripheral blood mononuclear cells.

Analysis of suppressor activity in experimental allergic encephalomyelitis inhibited by graft-versus-host reaction

The induction of local graft-versus-host reaction (GvH) prior to the encephalitogenic challenge resulted in the conversion of acute experimental allergic encephalomyelitis (EAE) to the chronic-like EAE. This inhibitory effect of GvH on EAE development was cyclophosphamide (CY) sensitive. Cell-free supernatants of peripheral blood lymphocytes (PBL) isolated from guinea pigs with chronic-like EAE and during recovery from EAE showed suppressor activity on the in vitro proliferative response of myelin basic protein (MBP) sensitized PBL. The appearance of anaphylactic anti-MBP antibodies and a change in the ratio complement fixing: haemagglutinating (CF/HA) antibodies was also registered.

Interleukin production by human colostral cells after in vitro mitogen stimulation

Human colostral cells were pulsed with PHA, Con A, or LPS and cultivated in serum-free medium. The culture supernatants were tested for IL-1 activity in C3H/HeJ thymocyte assay and for IL-2 activity on human lymphoblasts. The IL-1 activity was the highest at the 24th h of cultivation and IL-2 activity at the 48th h of cultivation.