Expression and Clinical Significance of PTEN and Bcl-2 in Nasopharyngeal Carcinoma Tissue

Objective To investigate the expression and interrelationship of phospharase and tensill homolog deleted on chromosome ten(PTEN) and B-cell lymphoma/leukemia-2(Bcl-2) in NPC. To evaluate their clinical implications in carcinogenesis, development, invasion and metastasis of NPC. Methods The expression of PTEN and Bcl-2 was examined in 50 poorly differentiated NPC samples and 15 normal nasopharyngeal epithelium tissues using immunohistochemical staining (SP method). Results In 15 normal nasopharyngeal epithelium samples PTEN was highly expressed but Bcl-2 protein expression was limited to the basal cell layer. The positive rates of PTEN and Bcl-2 protein expressions were 22%(11/50), 82%(41/50) in NPC tissues, respectively. The differences between the NPC and normal nasopharyngeal epithelium in both PTEN and Bcl-2 expressions were significantly observed according to the statistical analysis results . PTEN but not Bcl-2 expression was associated with T stage, lymph nodes metastases. There was no correlation between PTEN and Bcl-2 expressions in NPC tissues. Conclusion Reduced or absent expression of PTEN and high expression of Bcl-2 were observed in NPC tissues, which implied their mutual cooperative role to participate in tumor occurrence, progression and metastasis of NPC.