title: Differential Akt signalling in non-seminomatous testicular germ cell tumors.
abstract: OBJECTIVE
  To investigate the protein kinase B (Akt) signalling proteins phosphatase and tensin homolog (PTEN), phosphorylated-Akt (p-Akt) and cyclin-dependent kinase inhibitor 1B (p27(Kip1)) in non-seminomatous germ cell tumors (NST) with a view to future investigative approaches.
  
  
  METHODS
  The expressions of PTEN, p-Akt and p27(Kip1) were immunohistochemically assessed in 17 teratomas, 27 embryonal cell carcinomas, 6 yolk sac tumors and 24 benign testicular parenchymas. The cytoplasmic and corresponding nuclear expressions were compared and correlated to tumor entity.
  
  
  RESULTS
  PTEN was dramatically reduced in all the NST subgroups. Concentrated nuclear p27(Kip1) and loss of the cytoplasmic form was found in teratomas and embryonal cell carcinomas. Neither altered expression nor negative Akt regulation was found. The yolk sac tumors showed late cytoplasmic shift of PTEN and p27(Kip1).
  
  
  CONCLUSIONS
  Both, the absence of overexpression of p-Akt and of negative correlations to PTEN and p27(Kip1) suggest that signalling of these parameters in NST might include additional mechanisms such as crosstalk to other pathways rather than classical Akt activation.
authors: Department of Urology, Eberhard Karls University, Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tuebingen, Germany.
authors: Joerg
authors: J
authors: Hennenlotter
authors: Bastian
authors: B
authors: Amend
authors: Ulrich
authors: U
authors: Vogel
authors: Markus
authors: M
authors: Renninger
authors: Christine
authors: C
authors: Springer
authors: Ursula
authors: U
authors: Kuehs
authors: Arnulf
authors: A
authors: Stenzl
authors: Jens
authors: J
authors: Bedke
mesh_terms: D000328:Adult; D018236:Carcinoma, Embryonal / Q000378:metabolism / Q000473:pathology; D002467:Cell Nucleus / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D018240:Endodermal Sinus Tumor / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000378:metabolism* / Q000473:pathology; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction; D013724:Teratoma / Q000378:metabolism / Q000473:pathology; D013736:Testicular Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: C436291:CDKN1B protein, human; D050760:Cyclin-Dependent Kinase Inhibitor p27; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human