Crosstalk between SOX Genes and Long Non-Coding RNAs in Glioblastoma.

Glioblastoma (GBM) continues to be the most devastating primary brain malignancy. Despite significant advancements in understanding basic GBM biology and enormous efforts in developing new therapeutic approaches, the prognosis for most GBM patients remains poor with a median survival time of 15 months. Recently, the interplay between the SOX (SRY-related HMG-box) genes and lncRNAs (long non-coding RNAs) has become the focus of GBM research. Both classes of molecules have an aberrant expression in GBM and play essential roles in tumor initiation, progression, therapy resistance, and recurrence. In GBM, SOX and lncRNAs crosstalk through numerous functional axes, some of which are part of the complex transcriptional and epigenetic regulatory mechanisms. This review provides a systematic summary of current literature data on the complex interplay between SOX genes and lncRNAs and represents an effort to underscore the effects of SOX/lncRNA crosstalk on the malignant properties of GBM cells. Furthermore, we highlight the significance of this crosstalk in searching for new biomarkers and therapeutic approaches in GBM treatment.

Current Opportunities for Targeting Dysregulated Neurodevelopmental Signaling Pathways in Glioblastoma.

Glioblastoma (GBM) is the most common and highly lethal type of brain tumor, with poor survival despite advances in understanding its complexity. After current standard therapeutic treatment, including tumor resection, radiotherapy and concomitant chemotherapy with temozolomide, the median overall survival of patients with this type of tumor is less than 15 months. Thus, there is an urgent need for new insights into GBM molecular characteristics and progress in targeted therapy in order to improve clinical outcomes. The literature data revealed that a number of different signaling pathways are dysregulated in GBM. In this review, we intended to summarize and discuss current literature data and therapeutic modalities focused on targeting dysregulated signaling pathways in GBM. A better understanding of opportunities for targeting signaling pathways that influences malignant behavior of GBM cells might open the way for the development of novel GBM-targeted therapies.

SOX transcription factors and glioma stem cells: Choosing between stemness and differentiation.

Glioblastoma (GBM) is the most common, most aggressive and deadliest brain tumor. Recently, remarkable progress has been made towards understanding the cellular and molecular biology of gliomas. GBM tumor initiation, progression and relapse as well as resistance to treatments are associated with glioma stem cells (GSCs). GSCs exhibit a high proliferation rate and self-renewal capacity and the ability to differentiate into diverse cell types, generating a range of distinct cell types within the tumor, leading to cellular heterogeneity. GBM tumors may contain different subsets of GSCs, and some of them may adopt a quiescent state that protects them against chemotherapy and radiotherapy. GSCs enriched in recurrent gliomas acquire more aggressive and therapy-resistant properties, making them more malignant, able to rapidly spread. The impact of SOX transcription factors (TFs) on brain tumors has been extensively studied in the last decade. Almost all SOX genes are expressed in GBM, and their expression levels are associated with patient prognosis and survival. Numerous SOX TFs are involved in the maintenance of the stemness of GSCs or play a role in the initiation of GSC differentiation. The fine-tuning of SOX gene expression levels controls the balance between cell stemness and differentiation. Therefore, innovative therapies targeting SOX TFs are emerging as promising tools for combatting GBM. Combatting GBM has been a demanding and challenging goal for decades. The current therapeutic strategies have not yet provided a cure for GBM and have only resulted in a slight improvement in patient survival. Novel approaches will require the fine adjustment of multimodal therapeutic strategies that simultaneously target numerous hallmarks of cancer cells to win the battle against GBM.

Genetic evaluation of newborns with critical congenital heart defects admitted to the intensive care unit.

Rapid and efficient diagnostics is crucial for newborns with congenital heart defects (CHD) in intensive care unit (ICU) but is often challenging. Given that genetic factors play a role in 20-30% cases of CHD, it is likely that genetic tests could improve both its speed and efficiency. We aimed to analyze the utility of rapid and cost-effective multiplex ligation dependent probe amplification analysis (MLPA) for chromosomal analysis in newborns with critical CHD. One hundred consecutive newborns admitted with critical CHD to the ICU were included in the study. Those with normal MLPA findings were further tested by chromosomal microarray and clinical exome sequencing. Overall, pathogenic/likely pathogenic variants were determined in ten (10%) newborns by MLPA, three (3%) by chromosomal microarray, and three (3%) by clinical exome sequencing. The most common variant detected was deletion of 22q11.2 region.Conclusion: MLPA is fast and cost-effective analysis that could be used as the first-tier test in newborns with critical CHD admitted to the ICU. What is Known: • MLPA is an established method for chromosome analysis in patients with CHD, but detection rate in newborns with critical CHD is unknown. What is New: • Study suggests that detection rate of casual variants using MLPA in newborns with critical CHD is 10%.

Improving the Diagnosis of Children with 22q11.2 Deletion Syndrome: A Single-center Experience from Serbia.

OBJECTIVE: The incidence of the 22q11.2 microdeletion among children who have at least two out of five major clinical criteria for 22q11.2 deletion syndrome. DESIGN: Prospective study. SETTING: University Childrens Hospital in Belgrade, Serbia between 2005 and 2014. PARTICIPANTS: 57 patients with clinical characteristics of 22q11.2 deletion syndrome. METHODS: Standard G-banding cytogenetic analysis was performed in all children, and the 22q11.2 genomic region was examined using fluorescence in situ hybridization (FISH). For patients with no deletion detected by FISH, multiplex ligation-dependent probe amplification (MLPA) analysis was also done in order to detect cryptic deletions of this region and to analyze other genomic loci associated with phenotypes resembling the syndrome. A selected group of patients diagnosed to have 22q11.2 microdeletion by FISH underwent MLPA testing in order to characterize the size and position of deletion. OUTCOME MEASURES: The frequency of 22q11.2 microdeletion among children with at least two of the five major characteristics of 22q11.2 deletion syndrome (heart malformations, facial dysmorphism, T-cell immunodeficiency, palatal clefts and hypocalcemia/hypoparathyroidism). RESULTS: Typical 22q11.2 microdeletion was detected in 42.1% of patients; heart malformation were identified in all of them, facial dysmorphism in 79.2%, immunological problems in 63.6%, hypocalcemia in 62.5% and cleft palate in 8.3%. CONCLUSION: A higher detection rate compared to one-feature criterion is obtained when at least two major features of 22q11.2 deletion syndrome are taking into consideration. The criteria applied in this study could be considered by centers in low-income countries.

SOX18 Is a Novel Target Gene of Hedgehog Signaling in Cervical Carcinoma Cell Lines.

Although there is much evidence showing functional relationship between Hedgehog pathway, in particular Sonic hedgehog, and SOX transcription factors during embryonic development, scarce data are available regarding their crosstalk in cancer cells. SOX18 protein plays an important role in promoting tumor angiogenesis and therefore emerged as a promising potential target in antiangiogenic tumor therapy. Recently it became evident that expression of SOX18 gene in tumors is not restricted to endothelium of accompanying blood and lymphatic vessels, but in tumor cells as well.In this paper we have identified human SOX18 gene as a novel target gene of Hedgehog signaling in cervical carcinoma cell lines. We have presented data showing that expression of SOX18 gene is regulated by GLI1 and GLI2 transcription factors, final effectors of Hedgehog signaling, and that modulation of Hedgehog signaling activity in considerably influence SOX18 expression. We consider important that Hedgehog pathway inhibitors reduced SOX18 expression, thus showing, for the first time, possibility for manipulationwith SOX18 gene expression. In addition, we analyzed the role of SOX18 in malignant potential of cervical carcinoma cell line, and showed that its overexpression has no influence on cells proliferation and viability, but substantially promotes migration and invasion of cells in vitro. Pro-migratory effect of SOX18 suggests its role in promoting malignant spreading, possibly in response to Hedgehog activation.

Human embryonal carcinoma cells in serum-free conditions as an in vitro model system of neural differentiation.

Serum is generally regarded as an essential component of many eukaryotic cell culture media, despite the fact that serum composition varies greatly and may be the source of a wide range of artefacts. The objective of this study was to assess serum-free growth conditions for the human embryonal carcinoma cell line, NT2/D1. These cells greatly resemble embryonic stem cells. In the presence of retinoic acid (RA), NT2/D1 cells irreversibly differentiate along the neuronal lineage. We have previously shown that the early phases of neural induction of these cells by RA involve the up-regulation of SOX3 gene expression. Our goal was to compare RA-induced differentiation of NT2/D1 cells in serum-containing and serum-free media, by using SOX3 protein levels as a marker of differentiation. We found that NT2/D1 cells can be successfully grown under serum-free conditions, and that the presence or absence of serum does not affect the level of SOX3 protein after a 48-hour RA induction. However, six days of RA treatment resulted in a marked increase in SOX3 protein levels in serum-free media compared to serum-containing media, indicating that serum might have an inhibitory effect on the expression of this neural differentiation marker. This finding is important for both basic and translational studies that hope to exploit cell culture conditions that are free of animal-derived products.

The role of modern imaging techniques in the diagnosis of malposition of the branch pulmonary arteries and possible association with microdeletion 22q11.2.

Malposition of the branch pulmonary arteries is a rare malformation with two forms. In the typical form, pulmonary arteries cross each other as they proceed to their respective lungs. The "lesser form" is characterised by the left pulmonary artery ostium lying directly superior to the ostium of the right pulmonary artery, without crossing of the branch pulmonary arteries. Malposition of the branch pulmonary arteries is often associated with other congenital heart defects and extracardiac anomalies, as well as with 22q11.2 microdeletion. We report three infants with crossed pulmonary arteries and one adolescent with "lesser form" of the malformation. The results suggest that diagnosis of malposition of the branch pulmonary arteries could be challenging if based solely on echocardiography, whereas modern imaging technologies such as contrast computed tomography and magnetic resonance angiography provide reliable establishment of diagnosis. In addition, we performed the first molecular characterisation of the 22q11.2 region among patients with malposition of the branch pulmonary arteries and revealed a 3-megabase deletion in two out of four patients

Comparative analysis of SOX3 protein orthologs: Expansion of homopolymeric amino acid tracts during vertebrate evolution.

To understand more fully the structure and evolution of the SOX3 protein, we comparatively analyzed its orthologs in vertebrates. Since complex disorders are associated with human SOX3 polyalanine expansions, our investigation focused on both compositional and evolutionary analysis of various homopolymeric amino acid tracts observed in SOX3 orthologs. Our analysis revealed that the observed homopolymeric alanine, glycine, and proline tracts are mammal-specific, except for one polyglycine tract present in birds. Since it is likely that the SOX3 protein acquired additional roles in brain development in Eutheria, we might speculate that development of novel brain functions during the course of evolution was affected, at least in part, by such structural-functional changes in the SOX3 protein.