title: Clinical Analysis of PTEN, p53 and Her-2/neu Expressions in Thyroid Cancers.
abstract: OBJECTIVE
  The dual-specificity phosphatase PTEN/ MMAC1/TEP1 has recently been identified as the tumor suppressor gene most frequently mutated and/or deleted in human tumors. However, PTEN mutations have rarely been detected in sporadic thyroid cancers. Therefore, this study investigated the PTEN expression of thyroid cancer and the relationship between PTEN, clinical status and other biologic factors such as HER-2/neu and p53.
  
  
  METHODS
  The study samples consisted of 62 thyroid cancer specimens and 24 benign thyroid tumor specimens from patients who were operated on the Department of Surgery, Uijongbu St. Mary's hospital during the 5 years from January 1995 until January 2000. All tumors were studied by immunohistochemical staining using monoclonal antibodies against PTEN, HER-2/neu and p53. The results were analyzed statistically.
  
  
  RESULTS
  PTEN protein was found to be under-expressed more frequently in thyroid cancers (29%) than in benign thyroid tumors (4.2%). The reduction in PTEN expression in thyroid cancers was not significantly related with the recorded clinical factors such as size, age, lymph node metastasis and p53, except for HER-2 which was found to be significantly related (p=0.001). HER-2 over- expression was noted in thyroid cancer (83.8%) more frequently than in benign tumors (16.7%).
  
  
  CONCLUSIONS
  This study has demonstrated that the under-expression of PTEN protein and the over-expression of HER-2 protein may play a role in the carcinogenesis and development of thyroid cancer.
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: J S
authors.initials: JS
authors.lastname: Bae
authors.forename: K H
authors.initials: KH
authors.lastname: Kim
authors.forename: C H
authors.initials: CH
authors.lastname: Ahn
authors.forename: S J
authors.initials: SJ
authors.lastname: Oh
authors.forename: H M
authors.initials: HM
authors.lastname: Jeon
authors.forename: K W
authors.initials: KW
authors.lastname: Lim
authors.forename: C S
authors.initials: CS
authors.lastname: Chun
keywords: Her-2/neu gene; Immunohistochemical staining; PTEN gene; Thyroid neoplasm; p53 gene