title: Epigenetic inactivation of EFEMP1 is associated with tumor suppressive function in endometrial carcinoma.
abstract: OBJECTIVE
  EFEMP1, the epidermal growth factor-containing fibulin-like extracellular matrix protein 1, functions as an oncogene or a tumor suppressor depending on the cancer types. In this study, we aim to determine whether EFEMP1 affects the tumorigenesis and progression of endometrial carcinoma.
  
  
  METHODS
  The expression of EFEMP1 was investigated using immunohistochemistry in a panel of normal endometrium (n = 40), atypical hyperplasia (n = 10) and endometrial carcinoma tissues (n = 84). Methylation status of the EFEMP1 promoter was detected by methylation-specific PCR (MSP) and bisulphite genomic sequencing. Up- or down-regulation of EFEMP1 were achieved by stable or transient transfection with pCMV6/GFP/Neo-EFEMP1 or pGPU6/GFP/Neo-shEFEMP1 respectively. Effects of EFEMP1 on tumor proliferation, invasion and migration were evaluated by MTT, plate colony formation, Transwell and wound healing assay. The nude mouse tumor xenograft assay was used to investigate function of EFEMP1 in vivo.
  
  
  RESULTS
  Compared with normal endometrium (32/40) and atypical hyperplasia (7/10), EFEMP1 expression was much lower in endometrial carcinoma tissues (16/84) (P<0.001 and P = 0.02). EFEMP1 promoter was hypermethylated in endometrial carcinoma tissues (67%) as compared to normal tissue (10%) and down-regulation of EFEMP1 was associated with promoter hypermethylation. Treatment with 5-aza-2'-deoxycytidine (5-aza-dC) and/or trichostatin A (TSA) altered EFEMP1 methylation status, and restored EFEMP1 expression. Moreover, EFEMP1 decreased secretion of MMPs and inhibited tumor cell proliferation, metastasis and invasion in vitro and suppressed tumorigenesis in nude mice. Besides, EFEMP1 increased expression of E-cadherin and suppressed expression of vimentin in endometrial carcinoma.
  
  
  CONCLUSIONS
  EFEMP1 is a new candidate tumor suppressor gene in endometrial carcinoma, and is frequently silenced by promoter hypermethylation. It could inhibit tumor growth and invasion both in vitro and in vivo. Our findings propose that targeting EFEMP1 might offer future clinical utility in endometrial carcinoma.
authors.affiliation: Department of Obstetrics and Gynecology, Shanghai First People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Yang
authors.forename: Haifeng
authors.initials: H
authors.lastname: Qiu
authors.forename: Wei
authors.initials: W
authors.lastname: Bao
authors.forename: Bilan
authors.initials: B
authors.lastname: Li
authors.forename: Cong
authors.initials: C
authors.lastname: Lu
authors.forename: Guiqiang
authors.initials: G
authors.lastname: Du
authors.forename: Xin
authors.initials: X
authors.lastname: Luo
authors.forename: Lihua
authors.initials: L
authors.lastname: Wang
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wan
mesh_terms: D000818:Animals; D015820:Cadherins / Q000235:genetics; D063646:Carcinogenesis / Q000235:genetics / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D019175:DNA Methylation / Q000235:genetics; D018450:Disease Progression; D015536:Down-Regulation / Q000235:genetics; D004714:Endometrial Hyperplasia / Q000235:genetics / Q000473:pathology; D016889:Endometrial Neoplasms / Q000235:genetics* / Q000473:pathology*; D004717:Endometrium / Q000473:pathology; D044127:Epigenesis, Genetic / Q000235:genetics*; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D016147:Genes, Tumor Suppressor; D006801:Humans; D020782:Matrix Metalloproteinases / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000235:genetics; D014746:Vimentin / Q000235:genetics
chemical_list: D015820:Cadherins; C119630:EFEMP1 protein, human; D016326:Extracellular Matrix Proteins; D014746:Vimentin; D020782:Matrix Metalloproteinases