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WeiHong Ren,1,2 XuRan Zhang,2 WenBo Li,2 Qian Feng,2 HuiJie Feng,2 Yan Tong,2 Hao Rong,2 Wei Wang,2 Dai Zhang,2 ZhenQiang Zhang,3 ShiChun Tu,4 XiaoYan Zhu,1 QinXian Zhang11Department of Histology and Embryology, College of Basic Medicine, Zhengzhou University, Zhengzhou, Henan Province, People’s Republic of China; 2Department of Laboratory Medicine, The First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, Henan Province, People’s Republic of China; 3Immunology Laboratory of Chinese Medicine, Henan University of Chinese Medicine, Zhengzhou, Henan Province, People’s Republic of China; 4Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, USABackground: Myeloid-derived suppressor cells (MDSCs) promote immunosuppression in the tumor microenvironment, support tumor growth and survival, and may contribute to immunotherapy resistance. Recent studies showed that tumor-derived exosomes (TDEs) can induce MDSCs accumulation and expansion, the mechanisms of which are largely unknown.Methods: The morphologies and sizes of the exosomes was observed by using a JEM-1400 transmission electron microscope. MicroRNA(miR)-107 and ARG1, DICER1, PTEN, PI3K, AKT, mTOR, and NF-kB mRNAs were quantified by quantitative reverse tanscription PCR. Dual-Luciferase Reports Assay were used to examine the expression of genes which was targeted by miR-107. The expression of proteins were analyzed by using western blot.Results: MiR-107 was not only overexpressed in gastric cancer cells but also enriched in their secreted TDEs. Also, these miR-107 enriched TDEs could be taken up by HLA-DR-,CD33+,MDSCs, where miR-107 was able to target and suppress expression of DICER1 and PTEN genes. Dampened DICER1 expression supported expansion of MDSCs , while decreased PTEN led to activation of the PI3K pathway, resulting in increased ARG1 expression. Furthemore, gastric cancer-derived miR-107 TDEs, when dosed intravenously into mice, were also capable of inducing expansion of CD11b+,Gr1+/high ,MDSCs in mouse peripheral blood and altering expression of DICER1, PTEN, ARG1, and NOS2 in the MDSCs.Conclusions: Our findings demonstrate for the first time that gastric cancer-secreted exosomes are able to deliver miR-107 to the host MDSCs where they induce their expansion and activition by targeting DICER1 and PTEN genes, thereby may provide novel cancer therapeutics target for gastric cancer.Keywords: exosome, miRNA-107, myeloid-derived suppressor cell, arginase 1, gastric cancer

Diabetes-related infections have become challenging and important public health problems in China and around the world. P. aeruginosa plays an important role in diabetic foot infections. As a gram-negative opportunistic pathogen, P. aeruginosa causes recurrent and refractory infections that are characterized by biofilm formation. Previous studies have demonstrated that biofilm-challenged wounds typically take longer to heal than non-biofilm-challenged normal wounds in diabetic mouse models. In the present study, we sought to explore the mechanism via which insulin treatment affects cyclic di-GMP signaling in P. aeruginosa-infected chronic wounds in db/db diabetic mice. We found that the wounds of diabetic mice healed more slowly than those of nondiabetic mice. Moreover, wound healing in diabetic mice treated with insulin exhibited a considerable delay. Peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) was used to detect biofilms on P. aeruginosa-infected wound tissues. Increased intracellular c-di-GMP levels promoted biofilm formation in wound tissues from nondiabetic mice. Greater biofilm formation was observed in the wounds of insulin-treated diabetic mice than in the wounds of untreated diabetic mice or nondiabetic mice, in both the PAO1/p(lac)-yhjH- and PAO1-infected groups. Quantitative RT-PCR indicated that upon infection with PAO1/P(lac)-yhjH (the low c-di-GMP expression strain), the expression of IL-4 RNA was significantly higher in diabetic mice treated with insulin than in untreated diabetic mice or nondiabetic mice at each observation time point. Peak expression of IFN-γ occurred earlier in diabetic mice treated with insulin than in untreated diabetic mice with each of the experimental strains. Finally, P. aeruginosa harboring the plasmid pCdrA: gfp (s) was used as a reporter strain to monitor c-di-GMP levels. We found that insulin could promote biofilm formation by increasing intracellular c-di-GMP levels in vitro. Taken together, these data demonstrate that insulin treatment increases intracellular c-di-GMP levels, promotes biofilm formation and prolongs the inflammation period during the healing of infected wounds, resulting in delayed wound healing.

Yudi Ding, 1,* Nana Qi, 2,* Ke Wang, 1,* Yiming Huang, 2 Jinling Liao, 1 Hongxue Wang, 3 Aihua Tan, 3 Lihua Liu, 1 Zhenqiang Zhang, 1 Jinlong Li, 1 Jinliang Kong, 1 Shouming Qin, 1 Yonghua Jiang 2, 4, 5 1Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, People’s Republic of China; 2Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi 530021, People’s Republic of China; 3Department of Chemotherapy, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi 530021, People’s Republic of China; 4Guangxi Key Laboratory of Genomic and Personalized Medicine, Nanning, Guangxi 530021, People’s Republic of China; 5Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Nanning, Guangxi 530021, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yonghua Jiang; Shouming Qin Tel +86 13978695898; +86 18275710900Email qinshouming2008@126.com; jiangyonghua@126.comBackground: The fat mass and obesity-associated protein (FTO) was identified as a critical demethylase involved in regulating cellular mRNA stability by removing N6-methyladenosine (m6A) residues from mRNA. Emerging evidence has revealed that FTO is deeply implicated in lung cancer. However, knowledge of the function of FTO in lung adenocarcinoma (LUAC) is limited.Methods: FTO and FTO R96Q (R96Q), an FTO missense mutant lacking demethylase activity, were ectopically overexpressed, and FTO was knocked down via siRNA in A549 and H1299 cells. The relationships between FTO with cell characteristics and mRNA m6A levels were explored. Furthermore, RNA sequencing was performed on A549 cells.Results: FTO overexpression enhanced the proliferation, migration, and invasion ability of A549 and H1299 cells, decreased mRNA m6A levels. Interestingly, overexpression of R96Q, blunted the effects of FTO overexpression on cell proliferation and invasion. Through RNA sequencing analysis of A549 cells overexpressing FTO or R96Q and control A594 cells, 45 genes were identified as affected by m6A mRNA demethylation. Most of these genes were related to lung cancer, such as laminin γ 2, thrombospondin 1, nerve growth factor inducible, integrin alpha11, and proprotein convertase subtilisin/kexin type 9. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses suggested that these genes are fundamental to cancer development processes, such as cell migration and extracellular matrix organization.Conclusion: Our research shows that FTO facilitates LUAC cell progression by activating cell migration through m6A demethylation; however, further research on the mechanism underlying FTO activity in LUAC is necessary.Keywords: FTO, lung adenocarcinoma, m6A demethylase