2DE中IPG胶条转移到SDS-PAGE中的技术改进

2-维凝胶电泳(Two-dimensionalgelelectrophoresis,2DE)因其高通量、高分辨率等特点,被广泛用于蛋白质组的分离.然而,在蛋白质从第一向-固相(ImmobilizedpHgradients,IPG)胶条转移到第二向-十二烷基磺酸钠聚丙烯酰胺凝胶(Sodiumdodecylsulfate,SDS;Polyacrylamidegelelectrophoresis,PAGE)时,常会引起蛋白质的损失.尤其是当将IPG胶条放入浓缩胶上时,在胶面不平、技术不熟练等情况下,常会在IPG胶条下引入气泡,导致蛋白质更多的损失.现将IPG胶条转移过程进行改进:先在第二向的十二烷基磺酸钠聚丙烯酰胺凝胶上加上薄薄的一层(约1～2mm厚)琼脂糖溶液,然后将IPG胶条转移上去,最后再封住胶条的上面.这样的转移不会引起气泡,可以大大提高实验的成功率及重复性,有利于蛋白质的转移(尤其是相对分子质量大于40kDa的蛋白质),提高质谱鉴定的准确性.此法操作简便,可以减少因操作不熟练而带来的麻烦.

Expression and clinical significance of E-cadherin, β-catenin and E-cadherin-catenins complex in breast cancer and precancerous lesions

Objective： The aim of our study was to observe the expressions and clinical Significance of E-cadherin, β-catenin and E-cadherin-catenins complex in breast cancer and precancerous lesions, and analyze the relationship between the expressions and clinicopathological features in breast cancer. Methods： Immunhistochemical UltraSensitiveTM S-P method was employed to detect the expression of E-cadherin, β-catenin and E-cadherin-catenins complex in 128 cases of invasive ductal carcinomas, 89 cases of ductal carcinoma in situ and 57 cases of atypical ductal hyperplasia, 53 cases of usual ductal hyperplasia breast tissues were selected as a control group. The express of E-cadherin, β-catenin and their relationship with mult biological parameters including histological grade, region lymph node metastasis, distant metastasis and recurrence on files were also assessed. Results： （1） The staining patterns character of E-cadherin, β-catenin and E-cadherin-catenins complex： In UDH breast tissues, E-cadherin and a-catenin were expressed on cell membrane of ductal and acinic cells, showing cellular contour and border among cells. The abnormal expression of the three proteins occurred in breast invasive ductal carcinomas, ductal carcinoma in situ and atypical ductal hyperplasia tissues, showing cytoplasmic or nuclear staining, decrease and loss of cytomembrane staining. （2） The abnormal expression rates of E-cadherin, β-catenin and E-cadherin-catenins complex in invasive ductal carcinomas were 53.91%, 65.63% and 81.25%, which were significantly higher than that in ductal carcinoma in situ, atypical ductal hyperplasia, usual ductal hyperplasia tissues （P 〈 0.01）. Compared with usual ductal hyperplasia breast tissues group, the abnormal expression rates of E-cadherin, β-catenin and E-cadherin-catenins complex were significantly decreased （P 〈 0.01） in the breast cancer group. However, there was no significance of the abnormal expression rate between ductal carcinoma in situ and atypical ductal hyperplasia tissues groups （X2 = 0.76, P = 0.38; x2 = 0.14, P = 0.70; x2 = 0.81, P = 0.37; X2 = 2.19, P = 0.14） （P 〉 0.05）. （3） There was a significantly difference in the mean E-cadherin, β-catenin and E- cadherin-catenins complex frequency between estrogen receptor ＆ progesterone receptor positive IDC group and negative group, epidermal growth factor receptor type 2 （HER2/neu） positive and negative groups, Ki-67 proliferation index 〈 14% and 〉 14% groups, histological grade （I ＋ II） and grade III invasive ductal carcinomas groups, with lymph node metastasis, distant metastasis and recurrence groups （P 〈 0.05） and without groups （P 〈 0.05）. However, there was no difference in the mean E-cadherin, β-catenin and E-cadherin-catenins complex frequency between age （_〈 50 years vs 〉 50 years）, tumor diameter （〈 2 cm vs 〉 2 cm） （P 〉 0.05）. Conclusion： In breast cancer, the expressions of E-cadherin, β-catenin and E-cadherin-catenins complex are abnormally decreased and are correlated with pathology grade, differentiation disturbance and metastasis. E- cadherin and β-catenin may be as the predictors for prognosis. Combined detection may improve accuracy and sensitivity of predicting metastasis and prognosis of breast Cancer.

Oncogenic Role of Skp2 and p27^(Kip1) in Intraductal Proliferative Lesions of the Breast

Objective To investigate whether the connection of p27 Kip1 to S-phase kinase-associated protein 2 (Skp2) plays an oncogenic role in intraductal proliferative lesions of the breast. Methods Here we investigated the mechanism involved in association of Skp2's degradation of p27 Kip1 with the breast carcinogenesis by immunohistochemical method through detection of Skp2 and p27 Kip1 protein levels in 120 paraffin-embedded tissues of intraductal proliferative lesions including usual ductal hyperplasia (UDH, n=30), atypical ductal hyperplasia (n=30), flat epithelial atypia (FEA, n=30), and ductal carcinoma in situ (DCIS, n=30). Moreover, the expression status of Skp2 and p27 Kip1 in 30 cases of the normal breast paraffin-embedded tissues were explored. Results The DCIS group was with the highest Skp2 level and the lowest p27 Kip1 level, and the UDH group was with the lowest Skp2 level and the highest p27 Kip1 level. Both Skp2 and p27 Kip1 levels in the DCIS group were significantly different from those in the UDH group (all P<0.01). The levels of Skp2 and p27 Kip1 in the FEA group were significantly different from both the DCIS and UDH groups (all P<0.05). p27 Kip1 was negatively correlated with Skp2 in both the UDH group (r=-0.629, P=0.026) and DCIS group (r=-0.893, P=0.000). Conclusion Overexpression of Skp2 might be the mechanism underlying p27 Kip1 over degradation.

Correlation of VEGF expression,angiogenesis and carcinomatous change in breast tumors

Objective: The aim of the study was to detect the expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) in breast benign tissues and malignant tumors to clarify the relationship between VEGF expression, angiogenesis and breast carcinoma occurrence. Methods: The expression of VEGF and MVD in 79 cases of invasive ductal breast carcinoma, 79 corresponding para-cancer normal tissues from primary invasive breast carcinomas, 35 breast carcinoma in situ, 23 breast atypical hyperplasia and 56 breast fibroid tumor were examined by immunohistochemistry staining (SP-method). Results: The positive rate of VEGF and MVD value increased significantly with the increase of the malignant degree of breast tissues (P = 0.000). In breast carcinoma group, the positive rate of VEGF and MVD value with lymph node metastasis were higher than those without lymph node metastasis (P = 0.011 and P = 0.023). A significant higher expression of VEGF and MVD value were observed as the clinical stage increased (P = 0.035 and P = 0.012). The MVD value was higher in VEGF positive group than negative group (P = 0.000). Conclusion: The combining detection of VEGF expression and MVD is helpful for evaluating malignant degree of breast carcinoma. Angiogenesis in breast tumors and occurrence of breast carcinoma might be correlated with the expression of VEGF.

Quantitative profiles of the mRNAs of ER-α and its novel variant ER-α36 in breast cancers and matched normal tissues

Objective: The novel estrogen receptor-α (ER-α) variant ER-α36 is reported to be functional in the es-trogen signaling pathway and is related to tamoxifen resistance in breast cancer. However, ER-α36 tends to be a favorable factor for survival in patients without tamoxifen therapy. To investigate the mechanisms behind this paradox, we determined the differences between the transcriptional profiles of ER-α36 and full-length ER-α (ER-α66) in breast cancers and matched normal tissues. Methods: We analyzed ER-α36 and ER-α66 messenger RNA ( mRNA) levels in 74 pairs of breast cancers and matched normal tissues using a real-time quantitative polymerase chain reaction (PCR) assay, and correlated the results with their clinicopathological characteristics. Results: Breast cancers expressed lower ER-α36 mRNA levels than matched normal tissues regardless of their ER-α66 expression status. Down-regulation of ER-α36 mRNA was correlated with local progression, lymph node metastasis, and advanced cancer stage. The level of ER-α66 mRNA was lower in ER-α negative breast cancers compared with matched normal tissues. No differences in ER-α66 mRNA levels were observed during cancer progression. Conclusion: Down-regulation of ER-α36 is associated with carcinogenesis and progression of breast cancer.