Edited by George M. Carman Long non-coding RNAs (lncRNAs) have emerged as potential key regulators of the inflammatory response, particularly by modulating the transcriptional control of inflammatory genes. lncRNAs may act as an enhancer or suppressor to inflammatory transcription, function as scaffold molecules through interactions with RNA-binding proteins in chromatin remodeling complexes, and modulate dynamic and epigenetic control of inflammatory transcription in a gene-specific and time-dependent fashion. Here, we will review recent literature regarding the role of lncRNAs in transcriptional control of inflammatory responses. Better understanding of lncRNA regulation of inflammation will provide novel targets for the development of new therapeutic strategies.Because of the potentially destructive nature of the inflammatory response, the expression of inflammation-related genes is finely regulated at multiple levels, including transcription, mRNA processing, translation, phosphorylation, and degradation. Transcription represents an essential, and often the most important, regulatory determinant of the inflammation process. Many signaling pathways and transcription factors are involved in the inflammatory response, including the transcription factor nuclear factor-B (NF-B), 2 MAPK, and JAK/ STAT pathways, together controlling a multitude of inflammatory response genes (1, 2). Upon activation, these pathways directly activate and induce the expression of a limited set of transcription factors that promote the transcription of inflammatory genes. Whereas the mechanisms of initial activation and subsequent nuclear translocation of associated transcription factors for these signaling pathways are well-characterized, how the transcription of inflammatory genes is finely controlled in the nucleus to ensure that each individual gene is transcribed at the "right" place at the "right" time remains elusive. Perhaps this can be best represented by the inflammatory transcription induced by NF-B. The NF-B signaling cascade can be activated by inflammatory signals, including LPS, TNF-␣, IL-1␤, and reactive oxygen species, among others; many Toll-like receptors (TLRs) also activate NF-B (3-8).Prior to an activating signal, NF-B dimers are sequestered in the cytoplasm and held inactive by association with I B proteins (9). Activating stimuli cause I B degradation (10, 11), and consequently, free NF-B dimers translocate to the nucleus, bind to B sites, and promote gene transcription (12). Common targets of NF-B include inflammatory cytokines, chemokines, adhesion molecules, cytoprotective proteins, and proteins regulating cell differentiation, proliferation, and survival (13,14). In addition to its initial cytoplasmic activation, both the recruitment of NF-B to target genes in the nuclei and NF-B-induced transcriptional events after recruitment are finely controlled events to ensure proper transactivation of NF-B target genes (15). Indeed, several waves of gene transcription have been demonstrated in macrophages following LP...

Malignant pleural effusion (MPE) is a severe medical condition, which can result in breathlessness, pain, cachexia and reduced physical activity. It can occur in almost all types of malignant tumors; however, lung cancer is the most common cause of MPE, accounting for ~1/3 of clinical cases. Although there are numerous therapeutic approaches currently available for the treatment of MPE, none are fully effective and the majority can only alleviate the symptoms of the patients. Vascular endothelial growth factor (VEGF) has now been recognized as one of the most important regulatory factors in tumor angiogenesis, which participates in the entire process of tumor growth through its function to stimulate tumor angiogenesis, activate host vascular endothelial cells and promote malignant proliferation. Novel drugs targeting VEGF, including endostar and bevacizumab, have been developed and approved for the treatment of various tumors. Data from recent clinical studies have demonstrated that drugs targeting VEGF are effective and safe for the clinical management of MPE. Therefore, VEGF-targeting represents a promising novel strategy for the diagnosis and treatment of MPE. The present review summarized recent advances in the role of VEGF in the pathogenesis, diagnosis and clinical management of MPE in patients with non-small cell lung cancer.

Cryptosporidium is an important opportunistic intestinal pathogen for immunocompromised individuals and a common cause of diarrhea in young children in developing countries. Gastrointestinal epithelial cells play a central role in activating and orchestrating host immune responses against Cryptosporidium infection but underlying molecular mechanisms are not fully understood. We report here that C. parvum infection causes significant alterations in long non-coding RNA (lncRNA) expression profiles in murine intestinal epithelial cells. Transcription of a panel of lncRNA genes, including NR_045064, in infected cells is controlled by the nuclear factor-kappa B signaling. Functionally, inhibition of NR_045064 induction increases parasite burden in intestinal epithelial cells. Induction of NR_045064 enhances the transcription of selected defense genes in host cells following C. parvum infection. Epigenetic histone modifications are involved in NR_045064-mediated transcription of associated defense genes in infected host cells. Moreover, the p300/MLL-associated chromatin remodeling is involved in NR_045064-mediated transcription of associated defense genes in intestinal epithelial cells following C. parvum infection. Expression of NR_045064 and associated genes is also identified in intestinal epithelium in C57BL/6J mice following phosphorothioate oligodeoxynucleotide or lipopolysaccharide stimulation. Our data demonstrate that lncRNAs, such as NR_045064, play a role in regulating epithelial defense against microbial infection.

N 6-methyladenosine (m 6 A) RNA modification maintained by N6-methyltransferases and demethylases is involved in multiple biological functions. Methyltransferase like 3 (METTL3) is a major N 6-methyltransferase. However, the role of METTL3 and its installed m 6 A modification in colorectal tumorigenesis remains to be fully elucidated. METTL3 is highly expressed as indicated in colorectal cancer samples in the TCGA and Oncomine databases, implying its potential role in colon tumorigenesis. SW480 cell line with stable METTL3 knockout (METTL3-KO) was generated using CRISPR/Cas9 and were confirmed by the loss of METTL3 expression and suppression of m 6 A modification. The proliferation of METTL3-KO cells was significantly inhibited compared with that of control cells. METTL3-KO decreased the decay rate of suppressor of cytokine signaling 2 (SOCS2) RNA, resulting in elevated SOCS2 protein expression. m 6 A-RNA immunoprecipitation-qPCR (MeRIP-qPCR) revealed that SOCS2 mRNA was targeted by METTL3 for m 6 A modification. Similar to METTL3-KO SW480 cells, SW480 cells treated with 3-deazaadenosine, an RNA methylation inhibitor, exhibited elevated SOCS2 protein expression. Increased levels of SOCS2 in METTL3-KO SW480 cells were associated with decreased expression of leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), contributing to the inhibition of cell proliferation. The underlying associations among METTL3, SOCS2, and LGR5 were further confirmed in SW480 cells transfected with si-METTL3 and in tumor samples from patients with colorectal cancer. Taken together, our data demonstrate that an increased level of METTL3 may maintain the tumorigenicity of colon cancer cells by suppressing SOCS2.

Intestinal infection by Cryptosporidium parvum causes inhibition of epithelial turnover, but underlying mechanisms are unclear. Previous studies demonstrate that a panel of parasite RNA transcripts of low protein-coding potential are delivered into infected epithelial cells. Using in vitro and in vivo models of intestinal cryptosporidiosis, we report here that host delivery of parasite Cdg7_FLc_1000 RNA results in inhibition of epithelial cell migration through suppression of the gene encoding sphingomyelinase 3 (SMPD3). Delivery of Cdg7_FLc_1000 into infected cells promotes the histone methyltransferase G9a-mediated H3K9 methylation in the SMPD3 locus. The DNA-binding transcriptional repressor, PR domain zinc finger protein 1, is required for the assembly of Cdg7_FLc_1000 into the G9a complex and associated with the enrichment of H3K9 methylation at the gene locus. Pathologically, nuclear transfer of Cryptosporidium parvum Cdg7_FLc_1000 RNA is involved in the attenuation of intestinal epithelial cell migration via trans-suppression of host cell SMPD3.