The Significance Of The Expression Of RASSF1A In Breast Cancer And The Association With The Expression Of CerbB-2

Objective: Breast cancer is one of the malignant tumorswith the highest incidence for female and dose serious harm towomen's health for it's incidence is becoming higher and higher.The development and progression of breast cancer, which is acomplex, multistep progress including oncogene activation(egcerbB-2) and mutation or loss of tumour suppressor genes(egp53),correlates deeply with the expression of many genes andproteins. At present, multivariate analysis has been involved toassess the growth, development and prognosis of breast cancer.Besides tumour size, pathological stage and grade, lymph nodestatus, and ER and PR status, quantitative analysis of somegenes on molecular level has been used to evaluate theprogression and prognosis.Recently, RASSF1A(Ras association domain family 1A)was found to be an important suppressor factor for the growthand metastasis of breast cancer cell. In this research, RT-PCRwas used to determine the contants and differences of R-ASSF1A gene in the normal breast tissues and breast cancertissues in order to demonstrate its effect on the growth ,development and prognosis of breast cancer; And cerbB-2 wereexamined by immunohistochemical method in the same cancertissues to investigate its correlation with RASSF1A. Therelationship between RASSF1A and pathological grade, clinicalstage, and lymph node status was also studied .Such studieswould provided theoretical evidence for the early diagnosis andprognosis assessment of breast cancer.Methods: Malignant and nonneoplastic breast tissuessamples from 49 women were obtained from Department ofSurgery Fourth Hospital of HeBei Medical University fromDecember 2003 to March 2003. All patients were female withmedian age 49. RT-PCR was used to detect the contants ofRASSF1A in the malignant and normal tissues of breast. Theirdifferences were compared with cerbB-2 of the malignanttissues were examined by immunohistochemical s-p method.Statistic Methods: Statistic analysis was performed withSPSS software 10.0.Results: The expression of RASSF1A gene detected byRT-PCR: There are significant differences in the expression ofRASSF1A between the malignant and nonneoplastic breasttissues(p<0.01). The expression of former is lower than thelater. RASSF1A can be detected in all normal breast tissues, butonly 39% in tumor tissues. There is statistic relationshipbetween the differences and the following factors: histologicalgrade ,clinical stage, metastasis of lymph node (P<0.01).There is significant correlation between RASSF1A andcerbB-2's expression. In the same carcinoma tissue the higherthe cerbB-2 is expressed, the lower the RASSF1A.Statistic relationship between cerbB-2 and clinical factors:histological grade, clinical stage, and lymph node status is alsoconfirmed by this experiment.Conclusions1 There are higher expression of RASSF1A gene in normalbreast tissues than that in breast cancer tissues whose expressionis lower or absent. There are significant differences betweenthem, which indicated that RASSF1A may be one of tumorsuppressor factors. It can keep normal breast cells fromabnormally proliferating. Lower expression and absent ofRASSF1A gene will cause cancer cells to grow rapidly.2 There are statistic relationships between the expression ofcerbB-2 and clinical stage, histological grade and lymph nodestatus, which show the awful prognosis and short life span of thepatients whose cerbB-2 protein is highly expressed.3 There are also statistic negtive relationships between theexpression of RASSF1A and clinical stage, histological gradeand lymph node status, which show the awful prognosis andshort life span of the patients whose RASSF1A gene is lowlyexpressed or absent.4 Significant correlation is demonstrated between RAS-SF1A and cerbB-2's expression. In the same carcinoma tissuethe higher the cerbB-2 is expressed, the lower the RASSF1A ,which indicate that the expression of cerbB-2 and RASSF1Acan be applied to judge the degree of malignancy and...