The Relationship between PTEN Tumor Suppressor Gene and Vascular Endothelial Growth Factor-Mediated Angiogenesis in Breast Cancer

Background : PTEN is a novel tumor suppressor gene located at chromosome 10q23.3. Loss of PTEN function has been implicated in the progression of several types of cancer. Angiogenesis is a critical factor in tumor growth and metastasis. We investigated PTEN expression in invasive breast cancers and described its role in the regulation of angiogenesis related to vascular endothelial growth factor (VEGF). Methods : Forty-five, surgically resected, formalin-fixed and paraffin embedded breast cancer tissue samples were analyzed for PTEN and VEGF expressions by immunohistochemistry and for microvessel density (MVD) by CD34 immunostaining. Results : Loss of PTEN expression was found in 35.6% (16/45) of the breast cancer tissues, all of which showed positive VEGF expression. Among 29 cases with normal PTEN expression, 15 (51.7%) were VEGF positive. MVD was significantly higher in tumors with a loss of PTEN expression than in those with normal PTEN expression. Conclusion : A loss of PTEN expression might increase the VEGF-related angiogenesis in breast cancer. There was no correlation between PTEN expression and clinicopathologic parameters. Detection of the loss of PTEN expression may serve as a useful biologic marker for progression in invasive breast cancer.