Pulmonary preconditioning, injury, and inflammation modulate expression of the candidate tumor suppressor geneECRG4in lung

Abstract

Purpose The human c2orf40 gene encodes a candidate tumor suppressor called Esophageal Cancer-Related Gene-4 (ECRG4) that is a cytokine-like epigenetically-regulated protein that is characteristically downregulated in cancer, injury, inflammation, and infection. Here, we asked whether ECRG4 gene expression is detectable in lung epithelial cells and if its expression changes with inflammation, infection, and/or protective preconditioning. Materials and Methods We used immunoblotting, PCR, and quantitative PCR to measure ECRG4 and either inhalation anesthesia preconditioning, lipopolysaccharide injection, or laparotomy to modulate lung inflammation. Results Immunoblotting establishes the presence of the full-length 14 kDa ECRG4 peptide in mouse lung. Immunohistochemistry localizes ECRG4 to type l alveolar epithelial cells. Basal ECRG4 mRNA is greater than TNF-α, IL-1β, and IL-6 but following inflammatory lung injury, TNF-α, IL-1β, IL-6, and IL-10 are upregulated while ECRG4 gene expression is decreased. Similar findings are observed after an intravenous administration of lipopolysaccharide. In contrast, lung preconditioning with isoflurane anesthesia increases lung ECRG4 gene expression. Over-expression of ECRG4 in human lung epithelial cells in vitro decreases cell proliferation implying that a loss of ECRG4 in vivo would be permissive to cell growth. Conclusions This study supports the hypothesis that ECRG4 acts as a sentinel growth inhibitor in lung alveolar epithelial cells. Its downregulation by injury, infection, and inflammation and upregulation by preconditioning supports a role for ECRG4 in regulating the alveolar epithelium response to injury and inflammation. By extension, the findings support a functional consequence to its inhibition by promoter hypermethylation (i.e. lung cancer) and suggest potential benefits to its upregulation.

Exosomes in postshock mesenteric lymph are key mediators of acute lung injury triggering the macrophage activation via Toll‐like receptor 4

“…The NR8383 cells were stimulated with ML exosomes or PBS for 6 or 12 h, and total RNA was extracted using Trizol regent (Thermo Fisher Scientific). RNA concentrations and quality were determined by Nanodrop 2000 (Thermo Fisher Scientific), and 1 mg was reverse-transcribed using the iScript cDNA synthesis kit (Bio-Rad) as previously described (22). cDNA was used to quantify gene expression by real-time quantitiative PCR (iQ5 cycler; Bio-Rad) in a 25-ml reaction containing 100 nM of primers and iQ SYBR Green Supermix (Bio-Rad).…”

ECRG4 expression in normal rat tissues: expression study and literature review

“… 41 Decreased cell proliferation has been reported in human lung epithelial cells in response to ECRG4 over-expression. 16 …”

“… 6 Other authors have also recently reported ECRG4 full-length 14 kDa protein in mouse lung by immunoblotting and in type I alveolar cells by immunohistochemistry. 16 The aim of the present study was to analyse ECRG4 expression in a wide series of normal rat tissues by qPCR and immunohistochemistry, in order to establish its expression profiles in the rat. A detailed review of the available literature about ECRG4 functions has also been performed.…”

Soluble purified recombinant C2ORF40 protein inhibits tumor cell growth in vivo by decreasing telomerase activity in esophageal squamous cell carcinoma

“…The C2ORF40 gene is important in processes associated with physiological functional regulation, including inflammation, injury, senescence, the neuroendocrines environment, differentiation and apoptosis (5)(6)(7)(8)(9)(10)(11)(12)(13). Notably, previous studies have indicated that C2ORF40 is a candidate tumor suppressor gene associated with prognosis in a variety of tumors (4,(14)(15)(16)(17)(18)(19)(20)(21)(22).…”