FYB1-targeted modulation of CAPG promotes AML progression.

Acute myeloid leukemia (AML) is a rare and heterogeneous disease. Over the past few decades, patient prognosis has improved with continuous improvements in treatment, but outcomes for some patients with primary drug resistance or relapse after treatment remain poor. Additional therapies to improve outcomes for these patients are urgently needed. FYB1 expression differs substantially between AML tissues and normal tissues. High FYB1 expression is correlated with poorer overall survival (OS), indicating that FYB1 may regulate AML progression. Therefore, understanding the effect of FYB1 on AML could improve the success rate of therapeutic approaches and prognosis for patients with AML. In this study, through analysis of large databases and both in vivo and in vitro experiments, we assessed the expression and role of FYB1 in AML and the relationship of FYB with patient prognosis. Downstream targets of the FYB1 gene were analyzed by RNA-seq. Database mining and in vitro experiments were used to further clarify the effect of the downstream target gelsolin-like actin-capping protein (CAPG) on AML cells and its relationship with patient prognosis. FYB1 expression was significantly higher in AML tissue and corresponded with a poor prognosis. FYB1 knockdown inhibited AML cell proliferation, promoted cell apoptosis, reduced cell adhesion capability and significantly reduced the tumor formation rate in mice. In addition, FYB1 knockdown induced a notable decrease in CAPG expression. The suppression of CAPG significantly inhibited cell proliferation and increased cell apoptosis. The conclusions of this study underscore the pivotal role of the FYB1/CAPG axis in promoting AML. We propose that the FYB1/CAPG axis could serve as a new thread in the development of therapeutic strategies for AML.

Mycobacterium abscessus pulmonary disease presenting with spontaneous pneumomediastinum and subcutaneous emphysema in childhood acute lymphoblastic leukemia: a case report and literature review.

INTRODUCTION: Mycobacterium abscessus is a rapidly growing mycobacterium commonly identified in adults with underlying pulmonary diseases but is rarely observed in children. A better understanding of this pathogen in children is essential. CASE PRESENTATION: We report the case of a 49-month-old female child without previous underlying pulmonary diseases but with acute lymphoblastic leukemia (ALL). The patient was complicated with pneumonia during chemotherapy, which was primarily characterized by spontaneous pneumomediastinum and subcutaneous emphysema on chest computed tomography (CT). M. abscessus sequences were detected by metagenomic next-generation sequencing in bronchoalveolar lavage fluid. With mechanical ventilation, closed thoracic drainage, and anti-infective therapy for 6 months, the patient's infection was controlled. The patient completed 2.5 years of treatment for ALL, and the drugs were discontinued. The patient currently remains in complete hematologic remission. DISCUSSION: We reviewed the literature on 33 children with M. abscessus pulmonary disease. These children mostly had underlying immunodeficiency. Chest CT most often showed nodular shadows, consolidation, and bronchiectasis. Spontaneous pneumomediastinum and subcutaneous emphysema were not reported as major manifestations. CONCLUSION: Spontaneous pneumomediastinum and subcutaneous emphysema were our patient's main characteristics on chest CT, and this study enriches the knowledge regarding possible imaging changes in M. abscessus pulmonary disease in children. This case report reflects good clinical experience in maintaining the balance between chemotherapy and anti-infective therapy in childhood ALL.

Knockdown of Golgi phosphoprotein 73 blocks the trafficking of matrix metalloproteinase-2 in hepatocellular carcinoma cells and inhibits cell invasion.

Golgi phosphoprotein 73 (GP73) has been regarded as a novel serum biomarker for the diagnosis of hepatocellular carcinoma (HCC) in recent years. It has been reported that the upregulation of GP73 may promote the carcinogenesis and metastasis of HCC; however, the mechanisms remain poorly understood. In this study, GP73 correlates positively with matrix metalloproteinase-2 (MMP-2) in HCC-related cells and tissues. Further studies indicate that the knockdown of GP73 blocks MMP-2 trafficking and secretion, resulting in cell invasion inhibition. Additionally, the knockdown of GP73 induces the accumulation of intracellular MMP-2, which inhibits the phosphorylation of Src at Y416 and triggers the inhibition of SAPK/JNK and p53-p21 signalling pathways through a negative feedback loop. Finally, the transactivation of MMP2 was inhibited by the reduction in E2F1. This study reveals that GP73 plays functional roles in the trafficking and equilibrium of epithelial-mesenchymal transition (EMT)-related secretory proteins and that GP73 serves as a new potential target for combating the metastasis of HCC.

Adult-repopulating lymphoid potential of yolk sac blood vessels is not confined to arterial endothelial cells.

During embryogenesis, hematopoietic stem progenitor cells (HSPCs) are believed to be derived from hemogenic endothelial cells (HECs). Moreover, arterial feature is proposed to be a prerequisite for HECs to generate HSPCs with lymphoid potential. Although the molecular basis of hematopoietic stem cell-competent HECs has been delicately elucidated within the embryo proper, the functional and molecular characteristics of HECs in the extraembryonic yolk sac (YS) remain largely unresolved. In this study, we initially identified six molecularly different endothelial populations in the midgestational YS through integrated analysis of several single-cell RNA sequencing (scRNA-seq) datasets and validated the arterial vasculature distribution of Gja5+ ECs using a Gja5-EGFP reporter mouse model. Further, we explored the hemogenic potential of different EC populations based on their Gja5-EGFP and CD44 expression levels. The hemogenic potential was ubiquitously detected in spatiotemporally different vascular beds on embryonic days (E)8.5-E9.5 and gradually concentrated in CD44-positive ECs from E10.0. Unexpectedly, B-lymphoid potential was detected in the YS ECs as early as E8.5 regardless of their arterial features. Furthermore, the capacity for generating hematopoietic progenitors with in vivo lymphoid potential was found in nonarterial as well as arterial YS ECs on E10.0-E10.5. Importantly, the distinct identities of E10.0-E10.5 HECs between YS and intraembryonic caudal region were revealed by further scRNA-seq analysis. Cumulatively, these findings extend our knowledge regarding the hemogenic potential of ECs from anatomically and molecularly different vascular beds, providing a theoretical basis for better understanding the sources of HSPCs during mammalian development.

Comparison of Teratoma Formation between Embryonic Stem Cells and Parthenogenetic Embryonic Stem Cells by Molecular Imaging.

With their properties of self-renewal and differentiation, embryonic stem (ES) cells hold great promises for regenerative therapy. However, teratoma formation and ethical concerns of ES cells may restrict their potential clinical applications. Currently, parthenogenetic embryonic stem (pES) cells have attracted the interest of researchers for its self-renewing and pluripotent differentiation while eliciting less ethic concerns. In this study, we established a model with ES and pES cells both stably transfected with a double-fusion reporter gene containing renilla luciferase (Rluc) and red fluorescent protein (RFP) to analyze the mechanisms of teratoma formation. Transgenic Vegfr2-luc mouse, which expresses firefly luciferase (Fluc) under the promoter of vascular endothelial growth factor receptor 2 (Vegfr2-luc), was used to trace the growth of new blood vessel recruited by transplanted cells. Bioluminescence imaging (BLI) of Rluc/Fluc provides an effective tool in estimating the growth and angiogenesis of teratoma in vivo. We found that the tumorigenesis and angiogenesis capacity of ES cells were higher than those of pES cells, in which VEGF/VEGFR2 signal pathway plays an important role. In conclusion, pES cells have the decreased potential of teratoma formation but meanwhile have similar differentiating capacity compared with ES cells. These data demonstrate that pES cells provide an alternative source for ES cells with the risk reduction of teratoma formation and without ethical controversy.