A genetic variant in the MAST1 gene is associated with mega-corpus-callosum syndrome with hypoplastic cerebellar vermis, in a fetus.

BACKGROUND: Mega-corpus-callosum syndrome with cerebellar hypoplasia and cortical malformations is a rare neurological disorder that is associated with typical clinical and imaging features. The syndrome is caused by pathogenic variants in the MAST1 gene, which encodes a microtubule-associated protein that is predominantly expressed in postmitotic neurons in the developing nervous system. METHODS: Fetal DNA from umbilical cord blood samples and genomic DNA from peripheral blood lymphocytes were subjected to whole-exome sequencing. The potential causative variants were verified by Sanger sequencing. RESULTS: A 26-year-old primigravid woman was referred to our prenatal center at 25 weeks of gestation due to abnormal ultrasound findings in the brain of the fetus. The brain abnormalities included wide cavum septum pellucidum, shallow and incomplete bilateral lateral fissure cistern, bilateral dilated lateral ventricles, hyperplastic corpus callosum, lissencephaly, and cortical dysplasia. No obvious abnormalities were observed in the brainstem or cerebellum hemispheres, but the cerebellum vermis was small. Whole-exome sequencing identified a de novo, heterozygous missense variant, c.695T>C(p.Leu232Pro), in the MAST1 gene and a genetic diagnosis of mega-corpus-callosum syndrome was considered. CONCLUSION: This study is the first prenatal case of MAST1-related disorder reported in the Chinese population and has expanded the mutation spectrum of the MAST1 gene.

Histone deacetylase HDAC2 regulates microRNA-125a expression in neuroblastoma.

BACKGROUND: Neuroblastoma (NB) is an infrequent childhood malignancy of the peripheral sympathetic nervous system and is accountable for about 10% of pediatric tumors. microRNA (miR)-125a has been implicated to serve as a tumor suppressor in various cancers. Herein, we set out to ascertain whether miR-125a exerts antitumor effects in NB. METHODS: Downregulated miRNAs were identified by miRNA microarray analysis of NB tissues and paracancerous tissues. The expression of miR-125a in NB tissues and cells was detected by reverse transcription-quantitative (RT-q) PCR, followed by prognostic analysis. Gene Ontology (GO) enrichment analysis was performed on target genes of differentially expressed miRNAs. Cell proliferation, apoptosis, and differentiation were detected by cell counting kit-8 (CCK-8), Hoechst staining, immunofluorescence, and western blot. NB cells were injected into nude mice to detect tumorigenic, apoptotic, and differentiation activities in vivo. Dual-luciferase assay and chromatin immunoprecipitation (ChIP) were carried out to verify the binding relationship between miR-125a and PHOX2B or histone deacetylases 2 (HDAC2), respectively. Finally, rescue experiments were conducted. RESULTS: miR-125a was downregulated in NB tissues and cells, which was associated with poor prognosis. miR-125a reduced NB cell proliferation and augmented apoptosis and differentiation. NB cells with miR-125a overexpression decreased cell tumorigenesis and increased apoptosis and differentiation in xenograft tumor tissues. miR-125a targeted PHOX2B, which was highly expressed in NB tissues and cells. HDAC2, highly expressed in NB tissues and cells, repressed miR-125a transcription through histone deacetylation. Overexpression of HDAC2 or PHOX2B rescued the effects of miR-125a on NB cell proliferation, apoptosis, and differentiation. CONCLUSION: HDAC2 inhibited miR-125a transcription through deacetylation, and miR-125a suppressed NB development through binding to PHOX2B.

KLF5 promotes KIF1A expression through transcriptional repression of microRNA-338 in the development of pediatric neuroblastoma.

BACKGROUND: Neuroblastoma (NB) comprises about 8-10% of pediatric cancers, and microRNA (miR)-338 downregulation has been implicated in NB. However, the underlying molecular mechanism remains largely unclear. The main goal of this study is to probe the regulatory role of miR-338 and the upstream and downstream biomolecules involved in NB. METHODS: The differentially expressed miRNAs were screened by analyzing the NB gene expression microarray GSE121513 from the GEO database, and the differences in expression of the screened miRNAs were verified in clinically collected NB tissues versus dorsal root ganglions. Subsequently, the relationship between the miR-338 expression and NB cell growth was validated in vitro and in vivo, and the upstream and downstream regulatory mechanisms of miR-338 were further analyzed by bioinformatics. Functional rescue experiments were used to verify their effects on NB cell growth. RESULTS: miR-338 expressed poorly in NB tissues, and overexpression of miR-338 significantly inhibited NB cell growth in vitro and in vivo. The prediction results showed that miR-338 could target KIF1A, and miR-338 expression was negatively correlated with the expression of KIF1A. We further found that miR-338 was transcriptionally regulated by the transcription factor KLF5. Overexpression of KLF5 or KIF1A significantly attenuated the inhibitory effect of miR-338 mimic on NB cell growth. Finally, miR-338 blocked the Hedgehog signaling pathway by inhibiting the expression of KIF1A. CONCLUSION: Overexpression of KLF5 reduced expression of miR-338, which in turn increased the expression of KIF1A and activated the Hedgehog signaling pathway, leading to the progression of NB.

The combination of dextran sulphate and polyvinyl alcohol prevents excess aggregation and promotes proliferation of pluripotent stem cells in suspension culture.

OBJECTIVES: For clinical applications of cell-based therapies, a large quantity of human pluripotent stem cells (hPSCs) produced in standardized and scalable culture processes is required. Currently, microcarrier-free suspension culture shows potential for large-scale expansion of hPSCs; however, hPSCs tend to aggregate during culturing leading to a negative effect on cell yield. To overcome this problem, we developed a novel protocol to effectively control the sizes of cell aggregates and enhance the cell proliferation during the expansion of hPSCs in suspension. MATERIALS AND METHODS: hPSCs were expanded in suspension culture supplemented with polyvinyl alcohol (PVA) and dextran sulphate (DS), and 3D suspension culture of hPSCs formed cell aggregates under static or dynamic conditions. The sizes of cell aggregates and the cell proliferation as well as the pluripotency of hPSCs after expansion were assessed using cell counting, size analysis, real-time quantitative polymerase chain reaction, flow cytometry analysis, immunofluorescence staining, embryoid body formation, teratoma formation and transcriptome sequencing. RESULTS: Our results demonstrated that the addition of DS alone effectively prevented hPSC aggregation, while the addition of PVA significantly enhanced hPSC proliferation. The combination of PVA and DS not only promoted cell proliferation of hPSCs but also produced uniform and size-controlled cell aggregates. Moreover, hPSCs treated with PVA, or DS or a combination, maintained the pluripotency and were capable of differentiating into all three germ layers. mRNA-seq analysis demonstrated that the combination of PVA and DS significantly promoted hPSC proliferation and prevented cell aggregation through improving energy metabolism-related processes, regulating cell growth, cell proliferation and cell division, as well as reducing the adhesion among hPSC aggregates by affecting expression of genes related to cell adhesion. CONCLUSIONS: Our results represent a significant step towards developing a simple and robust approach for the expansion of hPSCs in large scale.

Establishment of a 3D model of tumor-driven angiogenesis to study the effects of anti-angiogenic drugs on pericyte recruitment.

Hepatocellular carcinoma (HCC), as a well-vascularized tumor, has attracted increasing attention in antiangiogenic therapies. Notably, emerging studies reveal that the long-term administration of antiangiogenic drugs induces hypoxia in tumors. Pericytes, which play a vital role in vascular stabilization and maturation, have been documented to be associated with antiangiogenic drug-induced tumor hypoxia. However, the role of antiangiogenic agents in regulating pericyte behavior still remains elusive. In this study, by using immunostaining analysis, we first demonstrated that tumors obtained from HCC patients were highly angiogenic, in which vessels were irregularly covered by pericytes. Therefore, we established a new 3D model of tumor-driven angiogenesis by culturing endothelial cells, pericytes, cancer stem cells (CSCs) and mesenchymal stem cells (MSCs) with microcarriers in order to investigate the effects and mechanisms exerted by antiangiogenic agents on pericyte recruitment during tumor angiogenesis. Interestingly, microcarriers, as supporting matrices, enhanced the interactions between tumor cells and the extracellular matrix (ECM), promoted malignancy of tumor cells and increased tumor angiogenesis within the 3D model, as determined by qRT-PCR and immunostaining. More importantly, we showed that zoledronic acid (ZA) reversed the inhibited pericyte recruitment, which was induced by sorafenib (Sora) treatment, through fostering the expression and activation of ErbB1/ErbB2 and PDGFR-ß in pericytes, in both an in vitro 3D model and an in vivo xenograft HCC mouse model. Hence, our model provides a more pathophysiologically relevant platform for the assessment of therapeutic effects of antiangiogenic compounds and identification of novel pharmacological targets, which might efficiently improve the benefits of antiangiogenic treatment for HCC patients.

ITGB1 Drives Hepatocellular Carcinoma Progression by Modulating Cell Cycle Process Through PXN/YWHAZ/AKT Pathways.

Integrin ß1 (ITGB1), which acts as an extracellular matrix (ECM) receptor, has gained increasing attention as a therapeutic target for the treatment of hepatocellular carcinoma (HCC). However, the underpinning mechanism of how ITGB1 drives HCC progression remains elusive. In this study, we first found that ITGB1 expression was significantly higher in HCC tissues than in normal controls by bioinformatics analysis. Furthermore, bioinformatics analysis revealed that paxillin (PXN) and 14-3-3 protein zeta (YWHAZ) are the molecules participating in ITGB1-regulated HCC tumor cell cycle progression. Indeed, immunohistochemistry (IHC) revealed that ITGB1, paxillin, and YWHAZ were strongly upregulated in paired HCC tissue compared with adjacent normal tissues. Notably, the inhibition of ITGB1 expression by small interfering RNA (siRNA) resulted in the downregulated expression of PXN and YWHAZ in primary HCC cells, as assessed by western blot and immunostaining. In addition, ITGB1 knockdown markedly impaired the aggressive behavior of HCC tumor cells and delayed cell cycle progression as determined by cell migration assay, drug-resistance analysis, colony formation assay, quantitative real-time polymerase chain reaction (qRT-PCR), and cell cycle analysis as well as cell viability measurements. More importantly, we proved that xenograft ITGB1high tumors grew more rapidly than ITGB1low tumors. Altogether, our study showed that the ITGB1/PXN/YWHAZ/protein kinase B (AKT) axis enhances HCC progression by accelerating the cell cycle process, which offers a promising approach to halt HCC tumor growth.

The role of long noncoding RNAs in regulating invasion and metastasis of malignant tumors.

Long noncoding RNAs (lncRNAs) are a group of non-protein-coding transcripts exceeding 200 nucleotides in length, which are emerging as key players in various fundamental biological processes. Furthermore, it is increasingly recognized that mutation and dysregulation of lncRNAs contribute importantly to a variety of human diseases, particularly human cancers. Previous studies have revealed that altered lncRNAs have a close association with tumorigenesis, metastasis, prognosis and diagnosis of cancers. The present review aims to exhibit a brief overview of the associated reports of lncRNAs in cancers, including colorectal cancer, gastric cancer, lung adenocarcinoma, nasopharyngeal carcinoma, cervical cancer and esophageal cancer. Altogether, we argue that lncRNAs have potential as new biomarkers in cancer prognosis and diagnosis, and as promising therapeutic targets for the prevention and treatment of human cancers.

Melanotic neuroectodermal tumor of infancy in ovary: A rare case report.

RATIONALE: Melanotic neuroectodermal tumor of infancy (MNTI) is an extremely rare benign pigmented neoplasm of neural crest origin with rapid expansile growth and a high recurrence rate. It is predominantly found in infants of <1 year of age, involvement of the head-and-neck region is the most common presentation though it is reported at other sites including mediastinum, shoulder, thigh, foot, epididymis, uterus and ovary. The patient reported here is the third case of MNTI presenting in an ovary, and the first reported in the infant ovary. PATIENT CONCERNS: A 33-month-old girl was presented to our unit for a huge abdominal mass. DIAGNOSIS: MNTI was eventually diagnosed by histological manifestations supplemented with immunohistochemical findings. INTERVENTIONS: Exploratory laparotomy and complete resection were conducted successfully. OUTCOMES: Postoperative course was uneventful and no recurrence was displayed in the 6-month follow-up. LESSONS: This case emphasizes that pediatric surgeons and pathologists must always consider the possibility of MNTI while dealing with ovarian neoplasms in infants. Although considered to be a benign tumor, proper treatment and close clinicoradiological follow-up of this tumor are of great importance.