Decreased expression of PinX1 protein is correlated with tumor development and is a new independent poor prognostic factor in ovarian carcinoma

Cancer Sci. 2010 Jun;101(6):1543-9. doi: 10.1111/j.1349-7006.2010.01560.x. Epub 2010 Mar 10.


Human interacting protein X1 (PinX1) has been identified as a critical telomerase inhibitor and proposed to be a putative tumor suppressor gene. Loss of PinX1 has been found in a large variety of malignancies, but the expression status in epithelial ovarian tumors has not been investigated. In this study, immunohistochemistry for PinX1 protein was performed on a tissue microarray (TMA) of epithelial ovarian tumors (informatively containing 25 cystadenomas, 29 borderline tumors, and 157 invasive carcinomas) and 12 normal ovaries. Receiver-operator curve (ROC) analysis was used to determine cut-off scores for tumor positivity and to evaluate patients' survival status. The threshold for PinX1 positivity was determined to be above 60% (area under the curve = 0.856, P < 0.001) based on the area under the ROC. Positive expression of PinX1 was observed in 100% of normal ovarian tissues, in 84% of cystadenomas, in 75.9% borderline tumors, and 66.2% of ovarian carcinomas. Decreased expression of PinX1 was strongly related to patients with poor prognostic factors regarding presence of lymph node metastasis (P = 0.024), distant metastasis (P < 0.001), and late International Federation of Gynecology and Obstetrics (FIGO) stage (P < 0.001). In univariate survival analysis, a highly significant correlation between loss of PinX1 and shortened patient survival (mean, 48.2 months vs 99.2 months, P < 0.001) was displayed. Multivariate analysis demonstrated PinX1 expression (P = 0.027) was evaluated as an independent parameter. Our findings suggest that loss of PinX1 is an adverse independent molecular marker for epithelial ovarian carcinoma patients. PinX1 may be a novel target for telomerase-based anticancer therapy due to inhibiting telomerase activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cell Cycle Proteins
  • Female
  • Humans
  • Immunohistochemistry
  • Middle Aged
  • Neoplasms, Glandular and Epithelial / etiology*
  • Neoplasms, Glandular and Epithelial / mortality
  • Neoplasms, Glandular and Epithelial / pathology
  • Ovarian Neoplasms / etiology*
  • Ovarian Neoplasms / mortality
  • Ovarian Neoplasms / pathology
  • Prognosis
  • Proportional Hazards Models
  • ROC Curve
  • Telomerase / analysis
  • Tumor Suppressor Proteins / analysis
  • Tumor Suppressor Proteins / physiology*


  • Cell Cycle Proteins
  • PINX1 protein, human
  • Tumor Suppressor Proteins
  • TERT protein, human
  • Telomerase