Aberrant microRNA expression in tumor mycosis fungoides.

Herein, miRNA candidates relevant to mycosis fungoides were investigated to provide data on the molecular mechanisms underlying the pathogenesis of the disease. The miRNA expression profile of skin biopsies from patients with tumor stage MF (tMF) and normal donors was compared using miRNA microarrays. Overall, 154 miRNAs were found differentially expressed between tMF and the control cohort with the majority of them being up-regulated (57 %). Among the upregulated miRNAs, miR-3177, miR-514b-3p, miR-1267, and miR-1282 were exclusively detected in 70 % of tMF. Additional upregulated miRNAs included miR-34a, miR-29a, let-7a*, and miR-210, while miR-200c* was identified among the downregulated ones. Quantitative real-time polymerase chain reaction was used to further investigate the expression profiles of miR-34a and miR-29a and validated the overexpression of miR-34a. Enrichment studies revealed that the target genes of the differentially expressed miRNAs were important in several cancer-related signaling pathways. The overlapping relationship of the target genes among tMF, Sezary syndrome, and atopic dermatitis revealed several common and disease-specific genes. Collectively, our study modulated miR-34a as a candidate oncogenic molecule and miR-29a as a putative tumor suppressor highlighting their promising potential in the molecular pathogenesis of tMF.

miR-15a and miR-24-1 as putative prognostic microRNA signatures for pediatric pilocytic astrocytomas and ependymomas.

In the current setting, we attempted to verify and validate miRNA candidates relevant to pediatric primary brain tumor progression and outcome, in order to provide data regarding the identification of novel prognostic biomarkers. Overall, 26 resected brain tumors were studied from children diagnosed with pilocytic astrocytomas (PAs) (n = 19) and ependymomas (EPs) (n = 7). As controls, deceased children who underwent autopsy and were not present with any brain malignancy were used. The experimental approach included microarrays covering 1211 miRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to validate the expression profiles of miR-15a and miR-24-1. The multiparameter analyses were performed with MATLAB. Matching differentially expressed miRNAs were detected in both PAs and EPs, following distinct comparisons with the control cohort; however, in several cases, they exhibited tissue-specific expression profiles. On correlations between miRNA expression and EP progression or outcome, miR-15a and miR-24-1 were found upregulated in EP relapsed and EP deceased cases when compared to EP clinical remission cases and EP survivors, respectively. Taken together, following several distinct associations between miRNA expression and diverse clinical parameters, the current study repeatedly highlighted miR-15a and miR-24-1 as candidate oncogenic molecules associated with inferior prognosis in children diagnosed with ependymoma.

MicroRNA:Siglec crosstalk in cancer progression.

Aberrant Siglec expression in the tumour microenvironment has been implicated in tumour malignancies and can impact tumour behaviour and patient survival. Further to this, engagement with sialoglycans induces masked antigen recognition and promotes immune evasion, highlighting deregulated immune function. This necessitates the elucidation of their expression profiles in tumour progression. MicroRNAs (miRNAs) mediated targeting represents a novel approach to further elucidate Siglec potential and clinical relevance. Although miRNA activity in Siglec expression remains limited, we highlight current literature detailing miRNA:Siglec interactions within the tumour landscape and provide insights for possible diagnostic and therapeutic strategies in targeting the Siglec/sialic acid axis.

SV2B/miR-34a/miR-128 axis as prognostic biomarker in glioblastoma multiforme.

Glioblastoma (GBM) is a heterogenous primary brain tumour that is characterised with unfavourable patient prognosis. The identification of biomarkers for managing brain malignancies is of utmost importance. MicroRNAs (miRNAs) are small, non-coding RNAs implicated in cancer development. This study aimed to assess the prognostic significance of miRNAs and their gene targets in GBM. An in silico approach was employed to investigate the differentially expressed miRNAs in GBM. The most dysregulated miRNAs were identified and analysed via Sfold in association with their gene target. The candidate gene was studied via multi-omics approaches, followed by in vitro and in vivo experiments. The in silico analyses revealed that miR-128a and miR-34a were significantly downregulated within GBM. Both miRNAs displayed high binding affinity to the synaptic vesicle glycoprotein 2B (SV2B) 3' untranslated region (3'UTR). SV2B exhibited upregulation within brain regions with high synaptic activity. Significantly higher SV2B levels were observed in high grade brain malignancies in comparison to their normal counterparts. SV2B expression was observed across the cytoplasm of GBM cells. Our findings underscored the downregulated expression patterns of miR-128a and miR-34a, alongside the upregulation of SV2B in GBM suggesting the importance of the SV2B/miR-34a/miR-128 axis as a potential prognostic approach in GBM management.

Analysis of somatic hypermutations of immunoglobulin gene rearrangements in childhood acute lymphoblastic leukemia.

The current study investigated the presence, frequency, and status of somatic hypermutations as well as their role in children with B lineage ALL. The obtained sequences were analyzed using IMGT/V-QUEST. Totally, 150 IGH sequences were evaluated; 139 from the 111 patients at the time of diagnosis and 11 from 8/111 patients at the time of relapse. The findings of the current report revealed the presence of somatically mutated V genes in childhood B lineage ALL. A higher frequency of somatic hypermutations was noted in unproductive rearrangements and was generally attributed to nucleotide mutation type, region, and IGHV gene subgroup biases.

Evaluation of antitumor activity of gefitinib in pediatric glioblastoma and neuroblastoma cells.

BACKGROUND: This work was undertaken to investigate the efficacy of gefitinib, an EGFR tyrosine kinase inhibitor, in tumor cell lines of the CNS by studying cell proliferation and phosphorylation of the tyrosine kinase domain of METHODS: The study included neuroblastoma (SHSY5Y) and glioblastoma (A172) cell lines. The MTT cell proliferation assay was performed in order to quantify the cytotoxic effect of gefitinib in A172 and SH-SY5Y cells, whilst ELISA assay was used to assess the effect on the phosphorylation of tyrosine residue 1068 of EGFR. RESULTS: As the concentration of gefitinib increased, MTT conversion into formazan was observed to progressively decrease, confirming the cytotoxic activity of gefitinib. In the ELISA assay for both cell lines investigated, as the dose of gefitinib increased, a gradual decrease in EGFR tyrosine phosphorylation was detected. CONCLUSIONS: The findings of the current study could form the basis of research regarding the use of novel inhibitors in the treatment of solid tumors in pediatric patients and a shift to targeted therapy with higher efficacy and fewer side effects.

Serum microRNA array analysis identifies miR-140-3p, miR-33b-3p and miR-671-3p as potential osteoarthritis biomarkers involved in metabolic processes.

BACKGROUND: MicroRNAs (miRNAs) in circulation have emerged as promising biomarkers. In this study, we aimed to identify a circulating miRNA signature for osteoarthritis (OA) patients and in combination with bioinformatics analysis to evaluate the utility of selected differentially expressed miRNAs in the serum as potential OA biomarkers. METHODS: Serum samples were collected from 12 primary OA patients, and 12 healthy individuals were screened using the Agilent Human miRNA Microarray platform interrogating 2549 miRNAs. Receiver Operating Characteristic (ROC) curves were constructed to evaluate the diagnostic performance of the deregulated miRNAs. Expression levels of selected miRNAs were validated by quantitative real-time PCR (qRT-PCR) in all serum and in articular cartilage samples from OA patients (n = 12) and healthy individuals (n = 7). Bioinformatics analysis was used to investigate the involved pathways and target genes for the above miRNAs. RESULTS: We identified 279 differentially expressed miRNAs in the serum of OA patients compared to controls. Two hundred and five miRNAs (73.5%) were upregulated and 74 (26.5%) downregulated. ROC analysis revealed that 77 miRNAs had area under the curve (AUC) > 0.8 and p < 0.05. Bioinformatics analysis in the 77 miRNAs revealed that their target genes were involved in multiple signaling pathways associated with OA, among which FoxO, mTOR, Wnt, pI3K/akt, TGF-ß signaling pathways, ECM-receptor interaction, and fatty acid biosynthesis. qRT-PCR validation in seven selected out of the 77 miRNAs revealed 3 significantly downregulated miRNAs (hsa-miR-33b-3p, hsa-miR-671-3p, and hsa-miR-140-3p) in the serum of OA patients, which were in silico predicted to be enriched in pathways involved in metabolic processes. Target-gene analysis of hsa-miR-140-3p, hsa-miR-33b-3p, and hsa-miR-671-3p revealed that InsR and IGFR1 were common targets of all three miRNAs, highlighting their involvement in regulation of metabolic processes that contribute to OA pathology. Hsa-miR-140-3p and hsa-miR-671-3p expression levels were consistently downregulated in articular cartilage of OA patients compared to healthy individuals. CONCLUSIONS: A serum miRNA signature was established for the first time using high density resolution miR-arrays in OA patients. We identified a three-miRNA signature, hsa-miR-140-3p, hsa-miR-671-3p, and hsa-miR-33b-3p, in the serum of OA patients, predicted to regulate metabolic processes, which could serve as a potential biomarker for the evaluation of OA risk and progression.

MicroRNA expression profiles in pediatric dysembryoplastic neuroepithelial tumors.

Among noncoding RNAs, microRNAs (miRNAs) have been most extensively studied, and their biology has repeatedly been proven critical for central nervous system pathological conditions. The diagnostic value of several miRNAs was appraised in pediatric dysembryoplastic neuroepithelial tumors (DNETs) using miRNA microarrays and receiving operating characteristic curves analyses. Overall, five pediatric DNETs were studied. As controls, 17 samples were used: the FirstChoice Human Brain Reference RNA and 16 samples from deceased children who underwent autopsy and were not present with any brain malignancy. The miRNA extraction was carried out using the mirVANA miRNA Isolation Kit, while the experimental approach included miRNA microarrays covering 1211 miRNAs. Quantitative real-time polymerase chain reaction was performed to validate the expression profiles of miR-1909* and miR-3138 in all samples initially screened with miRNA microarrays. Our findings indicated that miR-3138 might act as a tumor suppressor gene when down-regulated and miR-1909* as a putative oncogenic molecule when up-regulated in pediatric DNETs compared to the control cohort. Subsequently, both miRNA signatures might serve as putative diagnostic biomarkers for pediatric DNETs.

Frequency of FLT3 mutations in childhood acute lymphoblastic leukemia.

FLT3 mutations are occasionally observed in acute lymphoblastic leukemia (ALL). These most frequently manifest as internal tandem duplications (ITD) and activation loop (AL) mutations. This study investigated the incidence of FLT3 mutations in 86 pediatric patients diagnosed with ALL and the co-presence of common RAS mutations. A 2.3% (2/86) FLT3/AL mutation rate in terms of total ALL cases and a 22% (2/9) incidence in hyperdiploid cases was observed. This is in accordance to previous studies indicating a higher incidence in the patient subgroup associated with hyperdiploidy.

Adaptive resistance to biocides in Salmonella enterica and Escherichia coli O157 and cross-resistance to antimicrobial agents.

The mechanisms by which bacteria resist killing by antibiotics and biocides are still poorly defined, although repeated exposure to sublethal concentrations of antibacterial agents undoubtedly contributes to their development. This study aimed both to investigate the potential of Salmonella enterica and Escherichia coli O157 for adaptive resistance to commonly used biocides and to determine any cross-resistance to antibiotics. Strains were repeatedly passaged in media containing increasing concentrations of a biocide or antibiotic until adaptive resistance was obtained. A wide panel of antimicrobial agents was then screened by using the adapted strain to determine cross-resistance, if any. Adaptive resistance was readily achieved for both S. enterica and E. coli O157. Cross-resistance in adaptively resistant S. enterica varied with the serotype; Salmonella enterica serovar Enteritidis expressed cross-resistance to chloramphenicol, whereas Salmonella enterica serovar Typhimurium expressed cross-resistance to chlorhexidine. Benzalkonium chloride-resistant Salmonella enterica serovar Virchow showed elevated resistance to chlorhexidine; however, chlorhexidine-resistant Salmonella serovar Virchow did not demonstrate reciprocal cross-resistance to benzalkonium chloride, suggesting specific rather than generic resistance mechanisms. E. coli O157 strains acquired high levels of resistance to triclosan after only two sublethal exposures and, when adapted, repeatedly demonstrated decreased susceptibilities to various antimicrobial agents, including chloramphenicol, erythromycin, imipenem, tetracycline, and trimethoprim, as well as to a number of biocides. These observations raise concern over the indiscriminate and often inappropriate use of biocides, especially triclosan, in situations where they are unnecessary, whereby they may contribute to the development of microbial resistance mechanisms.