title: Phosphatase and tensin homolog (PTEN) pseudogene expression in endometrial cancer: a conserved regulatory mechanism important in tumorigenesis?
abstract: OBJECTIVE
  The PTEN pseudogene, PTENP1, was recently shown to play a role in cell proliferation in a prostate cancer model. In the present study, we sought to determine whether PTENP1 is expressed in endometrial cancer (EMCA) cell lines and primary tumors along with the microRNAs (miRNAs) that are predicted to regulate PTEN and PTENP1 transcript levels.
  
  
  METHODS
  RNA was prepared from six EMCA cell lines, three normal endometrial samples, and 61 primary tumors. TaqMan® RT-PCR was used to quantitate PTEN expression in all specimens and PTENP1 expression in cell lines, and normal endometrial (NE) samples. PTENP1 expression was evaluated using conventional RT-PCR in primary tumors. MicroRNA profiling was undertaken using NanoString(TM) technology in AN3CA and KLE cell lines. The relationship between PTEN transcript levels, PTENP1 expression, and PTEN mutation status was investigated.
  
  
  RESULTS
  All NE samples, cell lines, and primary tumors expressed PTEN. PTENP1 transcript was expressed in NE, cell lines, and 34/61 (56%) primary tumors. The median relative PTEN level was 2.9 arbitrary expression units in PTENP1-positive tumors and 2.3 in PTENP1-negative tumors (p=0.09). PTEN levels in wild-type and haploinsufficient tumors were variable compared to PTEN-null tumors (p=0.015). Four microRNAs predicted to bind PTEN/PTENP1 ranked in the top 20 most abundant microRNA subtypes in the AN3CA and KLE cell lines.
  
  
  CONCLUSIONS
  PTENP1 is expressed in NE and EMCA cell lines, as are PTEN/PTENP1 targeting inhibitory miRNAs (cell lines). Further studies are needed to evaluate the impact of PTEN/PTENP1/miRNA interactions on tumorigenesis regulation in EMCA.
authors: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine and Siteman Cancer Center, St. Louis, MO, USA. ioffey@wudosis.wustl.edu
authors: Yevgeniya J
authors: YJ
authors: Ioffe
authors: Katherine B
authors: KB
authors: Chiappinelli
authors: David G
authors: DG
authors: Mutch
authors: Israel
authors: I
authors: Zighelboim
authors: Paul J
authors: PJ
authors: Goodfellow
mesh_terms: D045744:Cell Line, Tumor; D016889:Endometrial Neoplasms / Q000201:enzymology* / Q000235:genetics; D005260:Female; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis / Q000235:genetics*; D011544:Pseudogenes; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human