Bacterial dysbiosis has emerged as an accomplice to carcinogenesis in malignancies such as colon and liver cancer, and we have recently implicated the microbiome in the pathogenesis of pancreatic ductal adenocarcinoma (PDA) 1. However, the mycobiome has not been clearly implicated in tumorigenesis. We found that fungi migrate from the gut lumen to the pancreas. PDA tumors harbored a ~3000-fold increase in fungi compared to normal pancreas in both mice and humans. The composition of the PDA mycobiome was distinct from that of gut or normal pancreas based on alpha and beta diversity indices. Specifically, the fungal community infiltrating PDA tumors was markedly enriched for Malassezia in both mice and humans. Fungal ablation was tumor-protective in slowly progressive and invasive models of PDA whereas repopulation with Malassezia-but not Candida, Saccharomyces, or Aspergillus-accelerated oncogenesis. In parallel, we discovered that ligation of mannose-binding lectin (MBL), which binds fungal wall glycans to activate the complement cascade, was required for oncogenic progression whereas MBL or C3 deletion in the extra-tumoral compartment or C3aR knockdown in tumor cells were protective. Further, reprogramming of the mycobiome did not alter PDA progression in Mbl or C3 deficient mice. Collectively, our work shows that pathogenic fungi promote PDA by driving the complement cascade via MBL activation.

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Background and Aims The recruitment and activation of inflammatory cells in the liver delineates the transition from hepatic steatosis to steatohepatitis (SH). Approach and Results We found that in SH, γδT cells are recruited to the liver by C‐C chemokine receptor (CCR) 2, CCR5, and nucleotide‐binding oligomerization domain‐containing protein 2 signaling and are skewed toward an interleukin (IL)‐17A+ phenotype in an inducible costimulator (ICOS)/ICOS ligand–dependent manner. γδT cells exhibit a distinct Vγ4+, PD1+, Ly6C+CD44+ phenotype in SH. Moreover, γδT cells up‐regulate both CD1d, which is necessary for lipid‐based antigens presentation, and the free fatty acid receptor, CD36. γδT cells are stimulated to express IL‐17A by palmitic acid and CD1d ligation. Deletion, depletion, and targeted interruption of γδT cell recruitment protects against diet‐induced SH and accelerates disease resolution. Conclusions We demonstrate that hepatic γδT cells exacerbate SH, independent of IL‐17 expression, by mitigating conventional CD4+ T‐cell expansion and modulating their inflammatory program by CD1d‐dependent vascular endothelial growth factor expression.

Long noncoding RNAs (lncRNAs) have been reported to play diverse roles in biologic and pathologic processes, including myogenesis. We found that lncRNA is highly expressed in skeletal muscle cells. Functional analyses showed that overexpression of promoted proliferation and restrained differentiation of myoblasts; whereas inhibition of had completely opposite effects In mice, knockdown of promoted muscle hypertrophy RNA molecules of acted mechanistically as competing endogenous RNAs to target micro-RNA (miR)-30c, which was supported by the results of bioinformatics analyses and dual-luciferase reporter assays. It has been shown that lncRNA competes with trinucleotide repeat containing-6A () for miR-30c. was previously reported to promote proliferation and inhibit differentiation of myoblast cells, whereas miR-30c targets the 3'-UTR of mRNA to weaken its function. Taken together, lncRNA promotes proliferation and inhibits differentiation of myoblast cells by attenuating function of miR-30c.-Liang, T., Zhou, B., Shi, L., Wang, H., Chu, Q., Xu, F., Li, Y., Chen, R., Shen, C., Schinckel, A. P. lncRNA promotes proliferation and suppresses differentiation of myoblasts in skeletal muscle development by attenuating the function of miR-30c.