Clinicopathological Significance Of NQO1Protein Overexpression In Uterine Cervical Squamous Cell Carcinoma

Backgrounds:NQO1(NAD (P) H:quinone oxidoreductase-1) is a kind of protecting cells against oxidative damage of yellow pigment enzyme, and also a kind of important chemical carcnogens in the body metabolic enzymes. Recent studies have revealed that NQO1is expressed at a high level in most human solid tumors including those of the colon, breast, pancreas, ovaries and thyroid, and it has also been detected following the induction of cell cycle progression and proliferation of melanoma cells. However, in the cervical cancer the study report is less.Objectives:To study the localization and clinicopathological significance of NQO1protein expression in cervical cells and cancer.Materials and methods:1. The NQO1expression in18cases of normal cervical epithelium,69cases of cervical intraepithelial neoplasia (CIN) and131cases of Squamous Cell Carcinoma (SCC) were investigated by immunohistochemical (IHC).2. Combined with HPV infection status, biological characteristics, and the clinical significance of NQO1protein expression in cervical cancer.3. To confirm with IHC result the localization of NQOl protein in SiHa cells were observed by IF.Results:1. The immunohistochemical analysis revealed that NQO1is widely distributed in the cytoplasm, a small number of cases showed cell membrane staining. The expression of NQO1was negative in normal cervix tissues. But compared with the control, the positive rates of NQO1in CIN-1, CIN-2and CIN-3were higher in order (P<0.01), the positive rates were33.33%(7/21)、50.00%(14/28)、55.00%(11/20), respectively; In cervical squamous cell carcinoma, positive rate of NQO1protein was obviously higher than the normal cervical epithelium (P<0.01), the positive rates were80.92%(106/131).2. The NQO1overexpression was closely related with the FIGO staging, differentiation and lymph node metastasis (P<0.05);3. NQO1protein expression level was not correlated with the patient age. Also, IF staining showed that, in SiHa cervical cancer cells, NQO1protein is mainly located at the cytoplasm and cell membrane, consistent with the results of IHC.Conclusions:NQO1may be a biomarker of cervical squamous cell carcinoma cell proliferation and therefore NQO1protein overexpression may have a clinificance in the diagnosis and prognosis of cervical cancer.