Loss of PTEN Expression in Primary Lung Cancer

Abstract

Background : The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene, a candidate tumor suppressor, is localized to chromosome 10q23 and shares extensive homology with cytoskeletal proteins auxilin and tensin. It appears to have multifunctional roles involved in cell proliferation, migration, and invasion. The role of PTEN alteration in the lung cancer and its relationship with other suppressor genes are not well established. Methods : Formalin-fixed, paraffin-embedded tissues from 105 patients with diagnosed with primary lung cancer were evaluated for PTEN and p53 protein expression using immunohistochemical methods. The results of the expression pattern of PTEN were compared with clinicopathological parameters and the expression pattern of p53. Results : Forty-seven (44.8%) of 105 cases had loss of PTEN expression. Loss of PTEN expression was significantly associated with histologic type (p<0.05), but did not correlate with tumor size, lymph node metastasis, and stage. There was no significant relationship between loss of PTEN expression and p53 expression, and no significant difference in clinicopathologic characteristics between particular groups of patterns with the four possible tumor carrying PTEN/p53 phenotypes. Conclusion : It is suggested that loss of PTEN expression occurs commonly in primary lung cancers and correlates with histologic type. Our results also support the proposed role of PTEN as a candidate tumor suppressor in lung cancer, and we suggest that there is a need for further study of this gene.