Expression And Significance Of P185 And P16 In Cervical Neoplasia

IntroductionCervical squamous cell carcinoma is the most common gynecologic malignant neoplasm . The occurrence of cervical carcinoma is the result of many steps and polygene . The activation of oncogenes and the absence of cancer suppressor genes is the molecular foundation . The molecular genetics of cervical carcinoma remains to be defined to a significant exent.The oncogene C-erbB-2 which belongs to EGFR families encodes P185 protein . When it is activated , the oncogene C-erbB-2 can make cells have malignant trends . When it is high expressed , P185 protein will change nomal membrane receptor into carcinoma protein . The message out of cell can activate many information ways , then lead to the malignant changes .Cancer suppressor gene P16 encodes P16 protein which is a cell-cycle inhibitor . P16 protein woks from stage G1 to stage S of cell-cycle by inhibiting the phosphoric procedure of Rb protein . When gene P16 inactivates , cell-cycle is out of control and progresses towards malignancy.In order to provide the theoretical basis of preventing , early diagnosing and curing cervical carcinoma , immunohistochemical streptavidi peroxidase(SP) method was used to examine the expression of P185 and P16 in normal cervical tissues, cervical intraepithelial neoplasias(CIN) and cervical squamous cell carcinoma(SCC) and study the expression and significance of P185 and P16 in Cervical Neoplasia .Materials and Methods Materials : 7 cases of normal cervical tissues , 27 cases of CIN (7 cases of CINI, 8 cases of CINII, 12 cases of CINIII and 31 cases of cervical squamous cell carcinoma were collected . We collected the clinical material including age , clinical stages , pathological grades.Instruments : Olympus light microscope(Japan), Ao microtome(U.S.A.), pressure cooker(China), incubator(China).Main reagents : Both rat anti-human P185 monoclonal antibody and rat anti-human P16 monoclonal antibody were applied without dilution from Maixin Biotech Ltd in Fujian .Method: Immunohistochemistry was employed with SP method . All procedures were Implemented according to the product illustration .Result judgement: The immunostaining of P185 is localized on the membrane and cytoplasm . Whereas the immunostaining of P16 is localized on the nucleus and cytoplasm . All the cases were divided into four groups based on the number of positive cells : (—) : there is no positive cells , (+): the number of positive cells is less than 50% ,(++) : the number of positive cells range from 50% to 75% , (+++) : the number of positive cells is more than 75%(including 75%) . It is judged positive from (+) to(+++)。Statistical method : Statistical evaluation was performed using chi-square , Fisher's exact probabilities or Spearman rank correlation . SPSS version 11.5 software was employed to analyze all datas . A p value less than 0.05 was considered statistically significant.Results1. The expression of P185 and P16 among different groups of cervicaltissuesThe oncogene C-erbB-2 encodes P185 protein . In normal cervical tissues , there was no positive expression . The positive rate of P185 protein in CIN and cervical squamous cell carcinoma was 33.3% and 71.0% respectively . There were highly significant differences between normal cervical tissues and cervical squamous cell carcinoma, CIN and cervical squamous cell carcinoma (P< 0.01).The positive rate of P16 protein in normal cervical tissues , CIN and cervical squamous cell carcinoma was 14.3% , 70.4% and 93.5% respectively . There were significant differences between these groups followed : normal cervical tissues and CIN , CIN and cervical squamous cell carcinoma(P< 0.05). There is highly significant differences between normal cervical tissues and cervical squamous cell carcinoma (P< 0.01).2. The relation of P185 and P16 with age, clinical stages, pathologicalgradesThe expression of P185 protein and P16 protein in cervical squamous cell carcinoma did not show significiant relation with age , clinical stages , pathological grades (P> 0.05).3. The relationship between P185 and P16 in cervical squamous cellcarcinomaThe expression of P185 was positively associated with that of P16(r =0.411 , P< 0.05).Conclusions1. P185 protein was no positive expression in normal cervical tissues . There were higher espressed in CIN tissues and cervical squamous cell carcinomal, and there were highly significant differences between them .2. The expression of P16 protein was negtive mainly , while the positive rate of P16 protein is higher in CIN and cervical squamous cell carcinoma , and there were significant differentces among them .3. The expression of P185 was positively associated with that of P16 .4. The expression of P185 and P16 are not significantly related to histological grade , clinical stage and age.