Expression of 14-3-3 sigma, cyclin-dependent kinases 2 and 4, p16, and Epstein-Barr nuclear antigen 1 in nasopharyngeal carcinoma.
OBJECTIVE
The protein 14-3-3 sigma plays a role in cell cycle arrest by sequestering cyclin-dependent kinase 1 cyclin B1 complexes, as well as cyclin-dependent kinases 2 and 4, hence its definition as a cyclin-dependent kinase inhibitor. However, the nature of the interaction between these biological markers in nasopharyngeal carcinoma is unknown. This study aimed to investigate whether altered expression of these markers contributes to nasopharyngeal carcinogenesis.


METHODS
The study population consisted of 30 nasopharyngeal carcinoma patients and 10 patients without nasopharyngeal carcinoma. The nasopharyngeal carcinoma cell lines TW02, TW04 and Hone-1 were also assessed. We analysed levels of messenger RNA and protein for the p16 gene and the 14-3-3 sigma, Epstein-Barr nuclear antigen 1, and cyclin-dependent kinase 2 and 4 proteins, in nasopharyngeal carcinoma tissue specimens and cell lines and in normal nasopharyngeal tissue.


RESULTS
Protein and messenger RNA levels for cyclin-dependent kinase 2 and Epstein-Barr nuclear antigen 1 were significantly higher in nasopharyngeal carcinoma compared with normal tissue, while levels of cyclin-dependent kinase 4 generally were not; results for 14-3-3 sigma varied. Nasopharyngeal carcinoma patients had diminished p16 gene expression, compared with normal tissue.


CONCLUSIONS
Levels of cyclin-dependent kinase 2 and Epstein-Barr nuclear antigen 1 were significantly higher in nasopharyngeal carcinoma than in normal tissue, while p16 gene expression was diminished. These three proteins may contribute to nasopharyngeal carcinogenesis.
Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
H-H
HH
Huang
Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
C-H
CH
Chen
Department of Pathology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
S-C
SC
Huang
Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
C-H
CH
Yang
Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
C-F
CF
Hwang
D048948:14-3-3 Proteins / Q000032:analysis*; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D002277:Carcinoma; D016022:Case-Control Studies; D045744:Cell Line, Tumor / Q000737:chemistry; D051357:Cyclin-Dependent Kinase 2 / Q000032:analysis*; D051358:Cyclin-Dependent Kinase 4 / Q000032:analysis*; D019941:Cyclin-Dependent Kinase Inhibitor p16; D019309:Epstein-Barr Virus Nuclear Antigens / Q000032:analysis*; D005095:Exoribonucleases / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000737:chemistry*; D009305:Nasopharynx / Q000737:chemistry; D009363:Neoplasm Proteins / Q000032:analysis*; D055815:Young Adult
D048948:14-3-3 Proteins; D014408:Biomarkers, Tumor; C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D019309:Epstein-Barr Virus Nuclear Antigens; D009363:Neoplasm Proteins; C495894:CDK2 protein, human; C495900:CDK4 protein, human; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D005095:Exoribonucleases; C413442:SFN protein, human