Expression And Significance Of Jab1 And P27kip1 Proteins In Laryngeal Squamous Cell Carcinoma

Background and ObjectiveLaryngeal squamous cell carcinoma (LSCC) is a common malignant neoplasm in Otolaryngology. In recent years, the morbidity of laryngocarcinoma appears an increasing tendency. It does great harm to people's health. It has become a highlight to investigate the oncogensis, developing, metastasis and management of the tumor at the molecule level. The cyclin-dependent kinase inhibitor(CDKI) p27^kip1, is a new class of tumor suppressor, which can influence cell proliferation by regulating the G1/S transition. Jun activation domain-binding protein 1( Jab1) is known as a coactivator of activator protein-1(AP-1), which can control the cell cycle by facilitating relocation of p27^kip1 from the nucleus to the cytoplasm, thereby accelerating the degradation of p27^kip1 by the ubiquitin/proteasome pathway. Jab1 overpression is closely associated with tumorigenesis, development and prognosis. The objective of this study is to investigate the expression of Jab1 and p27^kip1 and their association with clinicopathologic factors, and the correlation between expression of Jab1 and p27^kip1 in LSCC.MethodsThe expression of Jab1 and p27^kip1 was investigated in 23 cases of normal laryngeal tissues(NLT) and 57 cases of LSCC by SP immunohistochemistry staining.Results1. The positive rates of Jab1 in NTL and LSCC were 13.04%(3/23) and 54.39% (31/57) respectively, with a significant difference(P<0.01)between the two groups. Jab1 protein expression did not show significant correlation to degree of tumor differentiation(P>0.05), however it's expression was significantly associated with tumor size, lymph node metastasis and clinical stage(P<0.05).2 . The p27^kip1 protein was expressed in 82.61%(19/23) of NTL and 40.35%(23/57) of LSCC respectively, showing a significant difference (P<0.01). The p27^kip1 protein expression was significantly associated with lymph node metastasis(P<0.05), but not with degree of tumor differentiation, tumor size and clinical stage(P>0.05).3. Jab1 expression was negatively associated with p27^kip1 expression in LSCC(P<0.05).Conclusions1. Jab1 and p27^kip1 are closely correlated with tumorigenesis and metastasis in LSCC.2. Jab1 protein plays an important role in the development and progression of LSCC by facilitating the degradation of cell cycle inhibitor p27^kip1.3. Combination detection of the expression of Jab1 and p27^kip1 may be a useful indicator to evaluate the biological behavior of LSCC and to provide references for clinical therapy.