Mast cells-derived exosomes worsen the development of experimental cerebral malaria.

Cerebral malaria (CM) is the most severe neurological complication caused by Plasmodium falciparum infection. The accumulating evidence demonstrated that mast cells (MCs) and its mediators played a critical role in mediating malaria severity. Earlier studies identified that exosomes were emerging as key mediators of intercellular communication and can be released from several kinds of MCs. However, the potential functions and pathological mechanisms of MCs-derived exosomes (MCs-Exo) impacting on CM pathogenesis remain largely unknown. Herein, we utilized an experimental CM (ECM) model (C57BL/6 mice infected with P. berghei ANKA strain), and then intravenously (i.v.) injected MCs-Exo into P. berghei ANKA-infected mice to unfold this mechanism and investigate the effect of MCs-Exo on ECM pathogenies. We also used an in vitro model by investigating the pathogenesis development of brain microvascular endothelial cells line (bEnd.3 cells) co-cultured with P. berghei ANKA blood-stage soluble antigen (PbAg) after MCs-Exo treatment. The higher numbers of MCs and levels of MCs degranulation were observed in skin, cervical lymph node, and brain of ECM mice than those of the uninfected mice. Exosomes were successfully isolated from culture supernatants of mouse MCs line (P815 cells) and characterized by spherical vesicles with the diameter of 30-150 nm, and expression of typical exosomal markers (e.g., CD9, CD63, and CD81). The i.v. injection of MCs-Exo dramatically elevated incidence of ECM in the P. berghei ANKA-infected mice, exacerbated liver and brain histopathological damage, promoted Th1 cytokine response, aggravated brain vascular endothelial activation and blood brain barrier breakdown in ECM mice. In addition, the treatment of MCs-Exo led to the decrease of cells viability and mRNA levels of Ang-1, ZO-1, and Claudin-5, but increase of mRNA levels of Ang-2, CCL2, CXCL1, and CXCL9 in bEnd.3 cells co-cultured with PbAg in vitro. Taken together, our data indicated that MCs-Exo could worsen pathogenesis of ECM in mice.

Co-amplification of genes in chromosome 8q24: a robust prognostic marker in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a leading cause of tumor-associated death worldwide, owing to its high 5-year postoperative recurrence rate and inter-individual heterogeneity. Thus, a prognostic model is urgently needed for patients with HCC. Several researches have reported that copy number amplification of the 8q24 chromosomal region is associated with low survival in many cancers. In the present work, we set out to construct a multi-gene model for prognostic prediction in HCC. METHODS: RNA sequencing and copy number variant data of tumor tissue samples of HCC from The Cancer Genome Atlas (n=328) were used to identify differentially expressed messenger RNAs of genes located on the chromosomal 8q24 region by the Wilcox test. Univariate Cox and Lasso-Cox regression analyses were carried out for the screening and construction of a prognostic multi-gene signature in The Cancer Genome Atlas cohort (n=119). The multi-gene signature was validated in a cohort from the International Cancer Genome Consortium (n=240). A nomogram for prognostic prediction was built, and the underpinning molecular mechanisms were studied by Gene Set Enrichment Analysis. RESULTS: We successfully established a 7-gene prognostic signature model to predict the prognosis of patients with HCC. Using the model, we divided individuals into high-risk and low-risk sets, which showed a significant difference in overall survival in the training dataset (HR =0.17, 95% CI: 0.1-0.28; P<0.001) and in the testing dataset (HR = 0.42, 95% CI: 0.23-0.74; P=0.002). Multivariate Cox regression analysis showed the signature to be an independent prognostic factor of HCC survival. A nomogram including the prognostic signature was constructed and showed a better predictive performance in short-term (1 and 3 years) than in long-term (5 years) survival. Furthermore, Gene Set Enrichment Analysis identified several pathways of significance, which may aid in explaining the underlying molecular mechanism. CONCLUSIONS: Our 7-gene signature is a reliable prognostic marker for HCC, which may provide meaningful information for therapeutic customization and treatment-related decision making.

Development and validation of a nomogram for assessing survival in patients with hepatocellular carcinoma after hepatectomy.

BACKGROUND AND AIM: Assessing the average survival rate of patients with hepatocellular carcinoma (HCC) after hepatectomy is important for making critical decisions in everyday clinical practice. The present study aims to develop and validate a nomogram for assessing the overall survival probability for such patients. METHODS: The putative prognostic indicators for constructing the nomogram were identified using multivariable Cox regression and model selection based on the Akaike information criterion. The nomogram was subjected to internal and external validation. The nomogram endpoints were death within 1, 3, and 5 years. RESULTS: A consecutive sample of 522 HCC patients who underwent potentially curative hepatectomy was retrospectively analyzed. Age, Barcelona clinic liver cancer (BCLC) stage, tumor size, alanine transaminase, alpha fetal protein, and serum prealbumin were included in the final model. The nomogram's discriminative ability was good in the training set (C-index was 0.74 for 1 year, 0.73 for 3 years, 0.70 for 5 years) and was validated using both an internal bootstrap method (C-index was 0.73 for 1 year, 0.72 for 3 years, 0.69 for 5 years) and an external validating set (C-index was 0.72 for 1 year, 0.72 for 3 years, 0.69 for 5 years). The calibration plots for the endpoints showed optimal agreement between the nomogram's assessment and actual observations. CONCLUSIONS: The nomogram (an Excel-based tool) can be useful for assessing the probability of survival at 1, 3, and 5 years in patients with HCC after hepatectomy.