To investigate the expression of Abl-interacting protein 1 (ABI1) in normal gastric mucosal cell line GES-1 and gastric cancer cell line AGS, and the effects of ABI1 gene overexpression upon the proliferation of human gastric cancer cell AGS in vitro.Firstly the ABI1 expression in GES-1 and AGS cells were identified by immunohistochemistry, immunofluorescence, RT-PCR, real-time PCR and Western blot. Secondly human gastric cancer cell line AGS was cultured and transfected with recombinant MSCV-GFP-ABI1 plasmid or blank plasmid MSCV-GPF. Real-time PCR and Western blot were used to detect the mRNA and protein expression of ABI1. And lastly the cell proliferation was detected by CCK-8 assay.ABI1 was expressed both in normal gastric mucosal cell line GES-1 and in gastric cancer cell line AGS. Compared to GES-1 cells, the ABI1 expression in AGS cells was lowered significantly. There were no significant differences in the ABI1 mRNA and protein expression between the AGS and AGS-MSCV-GFP groups. Compared to those of the AGS group, the ABI1 mRNA expression levels of the AGS-MSCV-GFP-ABI1 group increased by 1.87 times (P = 0.002). The protein expression levels of the AGS-MSCV-GFP-ABI1 group were remarkably higher than those of the AGS and AGS-MSCV-GFP groups (P = 0.002). CCK-8 assay showed that there were no significant differences in the proliferation rates at different time points between the AGS and AGS-MSCV-GFP groups. However, the proliferation rates at the time points of 24, 48, 72 and 96 hours of the AGS-MSCV-GFP-ABI1 were 1.46 +/- 0.31, 4.75 +/- 0.12, 6.62 +/- 0.32 and 8.96 +/- 0.27 respectively. And they were significantly lower than the proliferation rates of the AGS and AGS-MSCV-GFP groups (P < 0.01).ABI1 gene is down-regulated in gastric cancer cells. The ABI1 overexpression effectively inhibits the proliferation in human gastric cancer cell lines. It suggests that ABI1 may be involved in gastric cancer pathogenesis by regulating the proliferation of gastric carcinomas cells.
G-protein coupled receptor (GPR 34) has been found to play important roles in some cancers and regulates the proliferation, apoptosis, and migration of these cancer cells. However, the mechanisms underlying how GPR34 functions to regulate growth and proliferation of colorectal cancer cells remains to be clarified.We employed stable GPR34 knockdown LS174T cell models, GPR34 Mab blocking, a CCK-8 kit, and a colony formation assay to characterize the effect of GPR34 on the proliferation of LS174T in vitro and xenograft tumor growth in vivo. The mRNA level of GPR34 was detected by RT-PCR in tumor tissues and adjacent normal tissues from 34 CRC patients.Based on RT-PCR results, GPR34 exhibited high level in tumor samples compared with adjacent normal samples. Increased expression of GPR34 is more associated with poor prognosis of CRC as shown in The Cancer Genome Atlas (TCGA) dataset by Kaplan-Meier survival analysis. Furthermore, we showed that GPR34 knockdown inhibited the proliferation of LS174T colon cancer cells and related xenograft tumor growth. Searching for the distinct molecular mechanism, we identified several contributors to proliferation of LS174T colon cancer cells: PI3K subunits/PTEN, PDK1/AKT, and Src/Raf/Ras/ERK. GPR34 knockdown inhibited the proliferation of LS174T cells by upregulating expression of PTEN, and downregulating expression of PI3K subunits p110-beta.Our findings provide direct evidence that GPR34 regulates the proliferation of LS174T cells and the growth of LS174T tumor xenografts by regulating different pathways. High expression of GPR34 mRNA could then be used to predict poor prognosis of CRC.
Abelson interactor 1 (ABI1) is associated with the metastasis and prognosis of many malignancies. The association between ABI1 transcript spliced variants, their molecular constitutive exons and exon-exon junctions (EEJs) in 14 cancer types and clinical outcomes remains unsolved.
Background/Aims: Patients with active ulcerative colitis (UC) have elevated levels of activated myeloid-derived leukocytes as a source of inflammatory cytokines.The selective depletion of these leukocytes by adsorptive granulocyte/monocyte apheresis (GMA) with an Adacolumn should alleviate inflammation, promote remission and enhance drug efficacy.However, studies have reported contrasting efficacy outcomes based on patients' baseline demographic variables.This study was undertaken to understand the demographic features of GMA responders and nonresponders.Methods: This was a multicenter study in China involving four institutions and 34 patients with active UC.Baseline conventional medications were continued without changing the dosage.The treatment efficacy was evaluated based on the endoscopic activity index and the Mayo score.Results: Thirty of the 34 patients completed all 10 GMA treatment sessions.The overall efficacy rate was 70.59%.The receiver operating characteristic analysis showed that the area under the curve was approximately 0.766 for a Mayo score of ≤5.5 with 0.273 specificity and 0.857 sensitivity (Youden index, 0.584) for GMA responders.No GMA-related serious adverse events were observed.Conclusions: The overall efficacy of GMA in patients with active UC who were taking first-line medications or were corticosteroid refractory was encouraging.Additionally, GMA was well tolerated and had a good safety profile.
The integrity of the intestinal mucosal barrier protects hosts against pathological conditions. Early mucosal restitution after wounding refers to epithelial cell migration into a defect. The RNA-binding protein HuR plays an important role in the posttranscriptional regulation of gene expression and is involved in many aspects of cellular physiology. In the present study, we investigated the role of HuR in the regulation of cell migration through the posttranscriptional regulation of Caveolin-1 (Cav-1). Online software was used to identify Cav-1 mRNA as a potential target of HuR. The interaction of HuR with Cav-1 mRNA was investigated via ribonucleoprotein immunoprecipitation (RNP IP) assays and biotin pulldown analysis. HuR was found to bind specifically to the Cav-1 3′-UTR rather than the coding region or 5′-UTR. Transfection of cells with siHuR decreased both HuR protein levels and Cav-1 protein levels; conversely, ectopic overexpression of HuR via infection of cells with an adenoviral vector containing HuR cDNA (AdHuR) increased Cav-1 protein levels without disturbing Cav-1 mRNA levels. Thus, HuR enhanced Cav-1 expression in vitro by stimulating Cav-1 translation. Intestinal epithelium-specific HuR knockout in mice decreased Cav-1 protein levels without changing Cav-1 mRNA levels, consistent with the in vitro results. Decreasing the levels of HuR via siHuR transfection inhibited early epithelial repair, but this effect was reversed by ectopic overexpression of GFP-tagged Cav-1. These results indicate that posttranscriptional regulation of Cav-1 gene expression by HuR plays a critical role in the regulation of rapid epithelial repair after wounding.
Horizontally acquired antibiotic resistance genes (ARGs) in bacteria are highly mobile and have been ranked as principal risk resistance determinants. However, the transfer network of the mobile resistome and the forces driving mobile ARG transfer are largely unknown. Here, we present the whole profile of the mobile resistome in 23,425 bacterial genomes and explore the effects of phylogeny and ecology on the recent transfer (≥99% nucleotide identity) of mobile ARGs. We found that mobile ARGs are mainly present in four bacterial phyla and are significantly enriched in Proteobacteria The recent mobile ARG transfer network, which comprises 703 bacterial species and 16,859 species pairs, is shaped by the bacterial phylogeny, while an ecological barrier also exists, especially when interrogating bacteria colonizing different human body sites. Phylogeny is still a driving force for the transfer of mobile ARGs between farm animals and the human gut, and, interestingly, the mobile ARGs that are shared between the human and animal gut microbiomes are also harbored by diverse human pathogens. Taking these results together, we suggest that phylogeny and ecology are complementary in shaping the bacterial mobile resistome and exert synergistic effects on the development of antibiotic resistance in human pathogens.The development of antibiotic resistance threatens our modern medical achievements. The dissemination of antibiotic resistance can be largely attributed to the transfer of bacterial mobile antibiotic resistance genes (ARGs). Revealing the transfer network of these genes in bacteria and the forces driving the gene flow is of great importance for controlling and predicting the emergence of antibiotic resistance in the clinic. Here, by analyzing tens of thousands of bacterial genomes and millions of human and animal gut bacterial genes, we reveal that the transfer of mobile ARGs is mainly controlled by bacterial phylogeny but under ecological constraints. We also found that dozens of ARGs are transferred between the human and animal gut and human pathogens. This work demonstrates the whole profile of mobile ARGs and their transfer network in bacteria and provides further insight into the evolution and spread of antibiotic resistance in nature.
Although post-cholecystectomy (PC) patients usually have gastrointestinal complications and a higher risk of colorectal cancer, previous studies undetected a heightened risk of inflammatory bowel disease. Thus, we tried to investigate cholecystectomy's impact and pathophysiological mechanism on murine colitis models and clarify the association among fecal bile acids (BAs), mucosal bacterial microbiota, and immune cells in the PC patients. One month or three months after cholecystectomy, mice have induced colitis and tested BAs and fecal microbiota analysis. Next, mice were treated with various cholecystectomy-accumulated bile acids in drinking water for three months before inducing colitis. All 14 paired PC patients and healthy subjects were enrolled for BAs and mucosal microbiota analysis. Cholecystectomy ameliorated DSS-induced murine colitis, accelerated mucosal repair, and induced a significant shifting of fecal microbiota and BAs profiles under colitis status, which featured a higher relative abundance of species involved in BAs metabolism and increased secondary BAs concentrations. Cholecystectomy-associated secondary BAs (LCA, DCA, and HDCA) also ameliorated DSS-induced colitis and accelerated mucosal repair in mice. Cholecystectomy and specific secondary BAs treatments inhibited monocytes/macrophages recruitment in colitis mice. In vitro, cholecystectomy-associated secondary BAs also downregulated monocytes chemokines in the THP-1 derived macrophages through activation of the LXRα-linked signaling pathway. The alterations of mucosal microbiota and fecal BAs profiles were found in the PC patients, characterized as increased species with potential immuno-modulating effects and secondary BAs, which were negatively associated with peripheral monocytes levels. Cholecystectomy-induced secondary bile acids accumulation ameliorated colitis through inhibiting monocyte/macrophage recruitment, which might be mediated by the LXRα-related signaling pathway. Cholecystectomy, after 3 months follow-up, has an immune-regulatory role in murine colitis, preliminarily explaining that no increased risk of IBD had been reported in the PC patients, which still warrants further studies.