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.