Upregulation of matrix metalloproteinase MMP-14 (MT1-MMP) is associated with poor prognosis in cancer patients, but it is unclear how MMP-14 becomes elevated in tumors. Here we show that miR-181a-5p is downregulated in aggressive human breast and colon cancers where its levels correlate inversely with MMP-14 expression. In clinical specimens, enhanced expression of MMP-14 was observed in cancer cells located at the invasive front of tumors where miR-181a-5p was downregulated relative to adjacent normal cells. Bioinformatics analyses defined a potential miR-181a-5p response element within the 3' untranslated region (UTR) of MMP-14 that was validated in reporter gene experiments. Ectopic miR-181a-5p reduced MMP-14 expression, whereas miR-181a-5p attenuation elevated MMP-14 expression. In support of a critical relationship between these two genes, miR-181a-5p-mediated reduction of MMP-14 levels was sufficient to decrease cancer cell migration, invasion and activation of pro-MMP-2. Further, this reduction in MMP-14 levels was sufficient to reduce in vivo invasion and angiogenesis in chick chorioallantoic membrane assays. Taken together, our results establish the regulation of MMP-14 in cancers by miR-181a-5p through a post-transcriptional mechanism, and they further suggest strategies to elevate miR-181a-5p to prevent cancer metastasis.
BackgroundHigh throughput parallel sequencing, RNA-Seq, has recently emerged as an appealing alternative to microarray in identifying differentially expressed genes (DEG) between biological groups. However, there still exists considerable discrepancy on gene expression measurements and DEG results between the two platforms. The objective of this study was to compare parallel paired-end RNA-Seq and microarray data generated on 5-azadeoxy-cytidine (5-Aza) treated HT-29 colon cancer cells with an additional simulation study.MethodsWe first performed general correlation analysis comparing gene expression profiles on both platforms. An Errors-In-Variables (EIV) regression model was subsequently applied to assess proportional and fixed biases between the two technologies. Then several existing algorithms, designed for DEG identification in RNA-Seq and microarray data, were applied to compare the cross-platform overlaps with respect to DEG lists, which were further validated using qRT-PCR assays on selected genes. Functional analyses were subsequently conducted using Ingenuity Pathway Analysis (IPA).ResultsPearson and Spearman correlation coefficients between the RNA-Seq and microarray data each exceeded 0.80, with 66%~68% overlap of genes on both platforms. The EIV regression model indicated the existence of both fixed and proportional biases between the two platforms. The DESeq and baySeq algorithms (RNA-Seq) and the SAM and eBayes algorithms (microarray) achieved the highest cross-platform overlap rate in DEG results from both experimental and simulated datasets. DESeq method exhibited a better control on the false discovery rate than baySeq on the simulated dataset although it performed slightly inferior to baySeq in the sensitivity test. RNA-Seq and qRT-PCR, but not microarray data, confirmed the expected reversal of SPARC gene suppression after treating HT-29 cells with 5-Aza. Thirty-three IPA canonical pathways were identified by both microarray and RNA-Seq data, 152 pathways by RNA-Seq data only, and none by microarray data only.ConclusionsThese results suggest that RNA-Seq has advantages over microarray in identification of DEGs with the most consistent results generated from DESeq and SAM methods. The EIV regression model reveals both fixed and proportional biases between RNA-Seq and microarray. This may explain in part the lower cross-platform overlap in DEG lists compared to those in detectable genes.
Cecal bascule is a rare clinical entity, which is mostly encountered in patients with peritoneal adhesions, mobile cecum, bowel dysfunction, and cecal displacement. In patients with recurrent or persistent abdominal pain and distension, cecal bascule should be considered. The majority of these patients require surgical management.
Hypoxic stress drives cancer progression by causing a transcriptional reprogramming. Recently, KIAA1199 was discovered to be a cell-migration inducing protein (renamed CEMIP) that is upregulated in human cancers. However, the mechanism of induction of CEMIP in cancer was hitherto unknown. Here we demonstrate that hypoxia induces CEMIP expression leading to enhanced cell migration. Immunohistochemistry of human colon cancer tissues revealed that CEMIP is upregulated in cancer cells located at the invasive front or in the submucosa. CEMIP localization inversely correlated with E-cadherin expression, which is characteristic of the epithelial-to-mesenchymal transition. Mechanistically, hypoxia-inducible-factor-2α (HIF-2α), but not HIF-1α binds directly to the hypoxia response element within the CEMIP promoter region resulting in increased CEMIP expression. Functional characterization reveals that CEMIP is a downstream effector of HIF-2α-mediated cell migration. Expression of CEMIP was demonstrated to negatively correlate with the expression of Jarid1A, a histone demethylase that removes methyl groups from H3K4me3 (an activation marker for transcription), resulting in altered gene repression. Low oxygen tension inhibits the function of Jarid1A, leading to increased presence of H3K4me3 within the CEMIP promoter. These results provide insight into the upregulation of CEMIP within cancer and can lead to novel treatment strategies targeting this cancer cell migration-promoting gene.
Intra-operative administration of iv water and electrolyte during bowel surgery, based on stroke volume measured using oesophageal Doppler, was associated with decreased complication rates.
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