mir-605-3p prevents liver premetastatic niche formation by inhibiting angiogenesis via decreasing exosomal nos3 release in gastric cancer.

BACKGROUND: Cancer-induced pre-metastatic niches (PMNs) play a decisive role in promoting metastasis by facilitating angiogenesis in distant sites. Evidence accumulates suggesting that microRNAs (miRNAs) exert significant influence on angiogenesis during PMN formation, yet their specific roles and regulatory mechanisms in gastric cancer (GC) remain underexplored. METHODS: miR-605-3p was identified through miRNA-seq and validated by qRT-PCR. Its correlation with the clinicopathological characteristics and prognosis was analyzed in GC. Functional assays were performed to examine angiogenesis both in vitro and in vivo. The related molecular mechanisms were elucidated using RNA-seq, immunofluorescence, transmission electron microscopy, nanoparticle tracking analysis, enzyme-linked immunosorbent assay, luciferase reporter assays and bioinformatics analysis. RESULTS: miR-605-3p was screened as a candidate miRNA that may regulate angiogenesis in GC. Low expression of miR-605-3p is associated with shorter overall survival and disease-free survival in GC. miR-605-3p-mediated GC-secreted exosomes regulate angiogenesis by regulating exosomal nitric oxide synthase 3 (NOS3) derived from GC cells. Mechanistically, miR-605-3p reduced the secretion of exosomes by inhibiting vesicle-associated membrane protein 3 (VAMP3) expression and affects the transport of multivesicular bodies to the GC cell membrane. At the same time, miR-605-3p reduces NOS3 levels in exosomes by inhibiting the expression of intracellular NOS3. Upon uptake of GC cell-derived exosomal NOS3, human umbilical vein endothelial cells exhibited increased nitric oxide levels, which induced angiogenesis, established liver PMN and ultimately promoted the occurrence of liver metastasis. Furthermore, a high level of plasma exosomal NOS3 was clinically associated with metastasis in GC patients. CONCLUSIONS: miR-605-3p may play a pivotal role in regulating VAMP3-mediated secretion of exosomal NOS3, thereby affecting the formation of GC PMN and thus inhibiting GC metastasis.

Carrier-Free Nanovaccine: An Innovative Strategy for Ultrahigh Melanoma Neoantigen Loading.

In personalized cancer immunotherapy, developing an effective neoantigen nanovaccine with high immunogenicity is a significant challenge. Traditional nanovaccine delivery systems often require nanocarriers, which can hinder the delivery of the neoantigen and cause significant toxicity. In this study, we present an innovative strategy of carrier-free nanovaccine achieved through direct self-assembly of 2'-fluorinated CpG (2'F-CpG) with melanoma neoantigen peptide (Obsl1). Molecular dynamics simulations demonstrated that the introduction of a fluorine atom into CpG increases the noncovalent interaction between 2'F-CpG and Obsl1, which enhanced the loading of Obsl1 on 2'F-CpG, resulting in the spontaneous formation of a hybrid 2'F-CpG/Obsl1 nanovaccine. This nanovaccine without extra nanocarriers showed ultrahigh Obsl1 loading up to 83.19 wt %, increasing the neoantigen peptide uptake by antigen-presenting cells (APCs). In C57BL/6 mice models, we demonstrated the long-term preventive and therapeutic effects of the prepared 2'F-CpG/Obsl1 nanovaccine against B16F10 melanoma. Immunocellular analysis revealed that the nanovaccine activated innate and adaptive immune responses to cancer cells. Hence, this study established a simple, safe, and effective preparation strategy for a carrier-free neoantigen nanovaccine, which could be adapted for the future design of personalized cancer vaccines in clinical settings.

HDAC4 promotes the growth and metastasis of gastric cancer via autophagic degradation of MEKK3.

BACKGROUND: Histone deacetylases (HDACs) have been shown to be involved in tumorigenesis, but their precise role and molecular mechanisms in gastric cancer (GC) have not yet been fully elucidated. METHODS: Bioinformatics screening analysis, qRT-PCR, and immunohistochemistry (IHC) were used to identify the expression of HDAC4 in GC. In vitro and in vivo functional assays illustrated the biological function of HDAC4. RNA-seq, GSEA pathway analysis, and western blot revealed that HDAC4 activated p38 MAPK signalling. Immunofluorescence, western blot, and IHC verified the effect of HDAC4 on autophagy. ChIP and dual-luciferase reporter assays demonstrated that the transcriptional regulation mechanism of HDAC4 and ATG4B. RESULTS: HDAC4 is upregulated in GC and correlates with poor prognosis. In vitro and in vivo assays showed that HDAC4 contributes to the malignant phenotype of GC cells. HDAC4 inhibited the MEF2A-driven transcription of ATG4B and prevented MEKK3 from p62-dependent autophagic degradation, thus activating p38 MAPK signalling. Reciprocally, the downstream transcription factor USF1 enhanced HDAC4 expression by regulating HDAC4 promoter activity, forming a positive feedback loop and continuously stimulating HDAC4 expression and p38 MAPK signalling activation. CONCLUSION: HDAC4 plays an oncogenic role in GC, and HDAC4-based targeted therapy would represent a novel strategy for GC treatment.

Expression of fatty acid-binding protein-4 in gastrointestinal stromal tumors and its significance for prognosis.

BACKGROUND: Fatty acid-binding proteins (FABPs) have been found to be involved in tumorigenesis and development. However, the role of FABP4, a member of the FABPs, in GISTs (Gastrointestinal stromal tumors) remains unclear. This study aimed to investigate the expression of FABP4 and its prognostic value in GISTs. METHODS: FABP4 expression in 125 patients with GISTs was evaluated by immunohistochemical analysis of tissue microarrays. The relationship between FABP4 expression and clinicopathological features and prognosis of GISTs was analyzed. RESULTS: Multiple logistic regression analysis showed that expression of FABP4 correlated with tumor size and mitotic index. Furthermore, FABP4 level, tumor size, mitotic index, and high AFIP-Miettinen risk were independent prognostic factors in GISTs. The Kaplan-Meier survival curve showed that the 5-year survival rate of patients with high-FABP4 expression GISTs was lower. CONCLUSIONS: These results suggested that high-FABP4 expression might be a marker of malignant phenotype of GISTs and poor prognosis.