PTEN Mutation Spectra Study Of The Breast Cancer

[Background and Objective]Breast carcinoma is one of the most frequently diagnosed severe female diseases. The incidence of breast cancer has been increasing since the industrilization of last century.It is crucial to diagnose and treat breast cancers in early stages. Breast hyperplasia, especially atypical hyperplasia is closely associated with breast cancer. There are morphologic similarities and epidemic correlations between breast hyperplasia and cancer, which suggests that they might have similar genetic or epigenetic alterations. According to modern molecular biological theory, a series of genetic or epigenetic alterations, especially the activation of oncogenes and the inhibition of tumor-suppressor genes have major contributions to the development of cancers. PTEN is the first tumor suppressor gene with dual specificity phosphatase activity. PTEN induces apoptosis, inhibites cell growth, regulates cell migration and adhesiveness. In addition, PTEN plays a pivotal role in embryonic development and the maintaince of immune system. PTEN affects the cell period and cell apoptosis through dephosphorylation modulation of multi-strip intracellular signal transduction pathway. In breast cancer, PTEN mutation and deletion ratio is very high。The defunction of PTEN is highly relation to the breast cancer malignization.So study the expression and function of PTEN is very important to comprehend the deduce mechanism of the breast cancer. At the same time, It offer the new index for the early diagnosis and prognosis estimation.[Methods]To collect 50 Greenness breast cancer samples and 50 cases near their cancer tissue as well as 50 breast benign hyperplasia tissue.All the cancer tissue are all diagnosed definitely as malignant and all the hyperplasia tissue are diagnosed as atypical hyperplasia.The control group conclude five cases of normal breast tissue.Extractioned the DNA of all the sample,then designed the primers of every exon。,Consequently got the augmentation production by PCR. By the method of the agarose gelatin DNA recycle we get the exon production which will be detected by the company then we can obtain the sequence result, At last we analyzed the outcome and depict the spectrum of the mutation of the PTEN gene.[Results]There are 31 cases mutated in the breast cancer(62%), 10 cases mutated in the tissue closely adjacent to the cancer(20%) and 3 cases mutated in the benign tumor (6%),Through the mutation spectra analysis,we get the mutation mainly located in the basic group 91042-91222 in the exon 5, The mutation rate is the 16% in the number 91215, 90217 and 14% in the number 91190．furthermore,The exon 7 also have the higher mutation rate,The mutation rate is the 14% in the number 115921．These all manifest PTEN exon5 and exon7 is the mutation hot spots. The chi squar test indicate the breast cancer with the tissue adjacent to the cancer and independent benign tumor have the significance difference.[Conclusion] 1．There are mutation and deletion of suppresser gene PTEN in breast cancer,It suggest that the detection of PTEN gene mutation can be the effect biology index of the breast malignant degree and prognosis determination. 2．Study suggested that tumor suppressor gene PTEN was abnormally expressed in primary breast carcinoma, PTEN probably plays an important role in the tumorigenesis and development of primary breast carcinoma.