title: Hypoxia suppresses E-cadherin and enhances matrix metalloproteinase-2 expression favoring esophageal carcinoma migration and invasion via hypoxia inducible factor-1 alpha activation.
abstract: The goal of this study was to explore the molecular mechanism of hypoxia inducible factor-1 alpha (HIF-1 alpha) action on migration and invasion of esophageal carcinoma cells. We used cobalt chloride (CoCl(2) ) to mimic tumor hypoxic microenvironment and analyzed the expressions of E-cadherin, matrix metalloproteinase-2 (MMP-2), and HIF-1 alpha in esophageal carcinoma cells under hypoxia by reverse transcription polymerase chain reaction and Western blotting. To analyze the function of HIF-1 alpha in Eca109 and TE1 cells, we established stable HIF-1 alpha knockdown cells using small interfering RNA. Blocking effect was detected by Western blotting. The concentrations of MMP-2 protein in the conditioned medium were also determined by enzyme-linked immunosorbent assay. Wound-healing and cell invasion assay were used to evaluate the migration and invasion of esophageal carcinoma cells. After exposure to hypoxia, expressions of HIF-1 alpha protein in Eca109 and TE1 cells were upregulated, both mRNA and protein levels of E-cadherin were downregulated, and MMP-2 were upregulated (P < 0.05), whereas HIF-1 alpha mRNA had no significant change (P > 0.05). Small interfering RNA could block HIF-1 alpha effectively under hypoxia, then enhanced E-cadherin expression and inhibited MMP-2 expression, respectively. Furthermore, expression of HIF-1 alpha protein was stable even though MMP-2 repressed by BB2516. Compared with that in normoxia, Snail expression was enhanced when Eca109 or TE1 cells exposed to hypoxia. Once HIF-1 alpha blocked, Snail expressions were inhibited accordingly. Wound recovery and the number of invading cells decreased (P < 0.05) after HIF-1 alpha blocked. The hypoxia suppresses E-cadherin expression and enhances MMP-2 expression favoring esophageal carcinoma migration and invasion via HIF-1 alpha activation. Our observations suggest that HIF-1 alpha inhibition might be an effective strategy to weaken the migration and invasion of esophageal carcinoma cells.
authors.affiliation: Department of Radiotherapy, the Fourth Hospital of Hebei Medical University, Shijiazhuang, China.
authors.forename: S-w
authors.initials: SW
authors.lastname: Jing
authors.forename: Y-d
authors.initials: YD
authors.lastname: Wang
authors.forename: L-Q
authors.initials: LQ
authors.lastname: Chen
authors.forename: M-x
authors.initials: MX
authors.lastname: Sang
authors.forename: M-m
authors.initials: MM
authors.lastname: Zheng
authors.forename: G-g
authors.initials: GG
authors.lastname: Sun
authors.forename: Q
authors.initials: Q
authors.lastname: Liu
authors.forename: Y-j
authors.initials: YJ
authors.lastname: Cheng
authors.forename: C-r
authors.initials: CR
authors.lastname: Yang
mesh_terms: D015153:Blotting, Western; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor / Q000378:metabolism / Q000473:pathology; D002465:Cell Movement / Q000235:genetics / Q000502:physiology*; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics* / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000473:pathology; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D015854:Up-Regulation
chemical_list: D015820:Cadherins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D034741:RNA, Small Interfering; D020778:Matrix Metalloproteinase 2