The Initial Research Of The Proteins Associated With Metastasis Of Breast Cancer By Proteomics

【Objective】To investigate the difference of protein profiles between two groups of breast carcinoma which with or without lymph node metastasis using 2D-PAGE and MELDI-TOF-MS.Then to comform some of those different proteins by immunohistochemistric stain in tissue microarray of breast carcinoma.In the hope of searching out some protein markers associated with lymph node metastasis of breast carcinoma and creating a foundation for further researches.【Methods】20 specimens of fresh breast cancer tissues were collected and classified into two groups by with and without lymph node metastasis,with 10 cases in each group respectively.Both the two groups were not significant difference between patient age,tumor size,histocal grade and the expression of ER,PR,HER-2,KI67.The proteins were extracted from these specimens and separated by 2D-PAGE.Then compare analysis of the difference protein spots through Image Master 2D Platinum 5.0 to get the spots intensity value.If the potency ratio＞2.0 that demonstration the spots have express discrepancy.Distinct protein spots were selected for mass spectrometry with MELDI-TOF-MS.To identified the proteins by search for NCBInr database which through Profound inquire software.Assessment the quality of frisking resultant by the probability that was foundation of Mowse value.The match score＞56 which indicated have significance sense,The protein was identified accurately.Stathmin and Ezrin protein expression was assayed by immunohistochemical method in 72 breast cancer cases.at the same time take 10 mammary benign lesion as comparison.【Results】(1) 214 protein spots were identified using mass spectrometry.There was a pair of 28 proteins completely matched,account33.7%;There were 86 matcheed proteins spots which was identified only one spot,account51.8%;There were 12 matched spots that were not the identical protein after identified.Among these 80 distinct proteins,45 have been reported to relate with invasion and metastasis of breast cancer,21 have been reported to relate with other tumors,and 14 have not been reported in cancer. (2) The expression of Stathmin was negative in the 10 benign lesion of mammary tissue. The positive expression of Stathmin localized at cytoplasm in breast cancer.The positive expression rate of Stathmin was 73.5%,47.4%in breast cancer that with and without lymph node metastasis.The difference of two sets have statistical significance(P<0.05), The expression of Stathmin was not associated with patient age,tumor size,histocal grade and the expression of ER,PR,,KI67,But strongly associated with the expression of HER-2.(3) The expression of Ezrin localized at inner cytomembrane of the glandular tube in benign lesions;The expression of Ezrin localized at cytomembrane and cytoplasm in breast cancer。The positive expression rate of Ezrin was 73.5%,47.4%in breast cancer that with and without lymph node metastasis.The difference of two sets have statistical significance(P<0.05),The expression of Ezrin was not associated with patient age,histocal grade and the expression of ER,PR,HER-2,KI67,But strongly associated with tumor size.【Conclusion】(1) Preliminary analysis shows that in breast cancer,there are many distinct proteins between lymph node metastasis group and non-metastasis group,Which indicated that breast cancer metastasis is related to many kinds of proteins.These distinct proteins selected in this research may play important roles in the genesis and development of breast cancer,which may lay a foundation for further study(2) The expressions of Stathmin and Ezrin were significant correlated with the metastasis of IDC.It is possible to estimate the metastatic potential of breast carcinomas by testing adequate metastasis-associated proteins.