Partially induced an EMT program [26]. Twists belong to bHLH transcription factor family which form either homo-or-heterodimers with other bHLH Microcystin-LR proteins to bind to a core E-box (CANNTG) sequence on the promoter region of target genes such as E-cadherin [17]. It has been reported that Twist2 could activate EMT programs to facilitate a cancer stem cell phenotype in breast cancer recently [19]. But how Twist2 participates in EMT of breast cancer in vivo remains poorly understood [19]. The present data indicate that Twist2 staining was a reliable predictor in the prognosis of breast cancer patients (Table 1). Twist2 increased significantly with tumor metastasis, especially in cytoplasm of ductal carcinoma of breast cells (Table 2). Additionally, cytoplasm Twist2 expression was mainly in ductal carcinoma of breast relative to lobular carcinoma (39.13 vs. 9.09 ). Twist1 has also been shown to be expressed in cytoplasm but not nucleus of human hepatocellular carcinoma (HCC), whereas E-cadherin was localized on membranes [27]. Twist2 overexpression was significantly linked to cervical cancer progression recently [28]. Therefore, these findings suggest that Twist2 plays a crucial role in the progression of breast carcinoma. Assessment of Twist2 expression status may provide clinically useful prognostic information in patients with breast cancer. Arising from epithelial tissues progressed to higher pathological grades of malignancy, breast cancer cells typically developedFigure 2. The expression patterns of ErbB2, Twist2 and Ecadherin 15900046 in human breast carcinomas. Representative images ErbB2, Twist2 and E-cadherin IHC staining in tumor central areas (TC, first and second row) and invasive front (IF, third and fourthrow) of the primary tumor, and surrounding lymph metastasis (LM, fifth and sixth row) are shown. Boxes indicate magnified regions in stained serial sections. Specific positive staining is shown in brown color, and Vasopressin chemical information nuclei were counterstained in blue. Tumor cells are clearly polarized in the differentiated gland-like or tubular structures areas in both primary tumor center and metastases. A high ErbB2 indicating strong proliferation (star) was detected only in differentiated area of TC and LM. Loss of gland-like growth tumor cells did not express ErbB2 in the corresponding IF. Twist2 is only detectable in the cytoplasm (arrows) in TC and LM. In contrast, tumor cells at the invasive front lose their polar orientation and display fibroblast-like shape. This morphological change is accompanied by nuclear accumulation of Twist2 (arrows). Consistently, tumor cells in differentiated areas of the primary tumor and in metastases express E-cadherin on cell membrane (arrowheads). Disseminating tumor cells at the invasive fronts with nuclear Twist2 completely lost E-cadherin (arrowheads). doi:10.1371/journal.pone.0048178.galterations in morphology as well as in their attachment to the extracellular matrix. This EMT process is 
characterized by the down-regulation of the molecular markers of epithelial cells together with the loss of intercellular adhesion. Loss of E-cadherin expression is a hallmark of EMT. As far as we know, Twist2 and Slug are also EMT inducers [23]. High level of Slug is a determinant in the progression of metastatic breast cancer [22,29]. Our results showed no correlation between Twist2, E-cadherin, and Slug (Table 3). Some of this controversy might be due to EMT being a transient, reversible process occurring during the course o.Partially induced an EMT program [26]. Twists belong to bHLH transcription factor family which form either homo-or-heterodimers with other bHLH proteins to bind to a core E-box (CANNTG) sequence on the promoter region of target genes such as E-cadherin [17]. It has been reported that Twist2 could activate EMT programs to facilitate a cancer stem cell phenotype in breast cancer recently [19]. But how Twist2 participates in EMT of breast cancer in vivo remains poorly understood [19]. The present data indicate that Twist2 staining was a reliable predictor in the prognosis of breast cancer patients (Table 1). Twist2 increased significantly with tumor metastasis, especially in cytoplasm of ductal carcinoma of breast cells (Table 2). Additionally, cytoplasm Twist2 expression was mainly in ductal carcinoma of breast relative to lobular carcinoma (39.13 vs. 9.09 ). Twist1 has also been shown to be expressed in cytoplasm but not nucleus of human hepatocellular carcinoma (HCC), whereas E-cadherin was localized on membranes [27]. Twist2 overexpression was significantly linked to cervical cancer progression recently [28]. Therefore, these findings suggest that Twist2 plays a crucial role in the progression of breast carcinoma. Assessment of Twist2 expression status may provide clinically useful prognostic information in patients with breast cancer. Arising from epithelial tissues progressed to higher pathological grades of malignancy, breast cancer cells typically developedFigure 2. The expression patterns of ErbB2, Twist2 and Ecadherin 15900046 in human breast carcinomas. Representative images ErbB2, Twist2 and E-cadherin IHC staining in tumor central areas (TC, first and second row) and invasive front (IF, third and fourthrow) of the primary tumor, and surrounding lymph metastasis (LM, fifth and sixth row) are shown. Boxes indicate magnified regions in stained serial sections. Specific positive staining is shown in brown color, and nuclei were counterstained in blue. Tumor cells are clearly polarized in the differentiated gland-like or tubular structures areas in both primary tumor center and metastases. A high ErbB2 indicating strong proliferation (star) was detected only in differentiated area of TC and LM. Loss of gland-like growth tumor cells did not express ErbB2 in the corresponding IF. Twist2 is only detectable in the cytoplasm (arrows) in TC and LM. In contrast, tumor cells at the invasive front lose their polar orientation and display fibroblast-like shape. This morphological change is accompanied by nuclear accumulation of Twist2 (arrows). Consistently, tumor cells in differentiated areas of the primary tumor and in metastases express E-cadherin on cell membrane (arrowheads). Disseminating tumor cells at the invasive fronts with nuclear Twist2 completely lost E-cadherin (arrowheads). doi:10.1371/journal.pone.0048178.galterations in morphology as well as in their attachment to the extracellular matrix. This EMT process is characterized by the down-regulation of the molecular markers of epithelial cells together with the loss of intercellular adhesion. Loss of E-cadherin expression is a hallmark of EMT. As far as we know, 
Twist2 and Slug are also EMT inducers [23]. High level of Slug is a determinant in the progression of metastatic breast cancer [22,29]. Our results showed no correlation between Twist2, E-cadherin, and Slug (Table 3). Some of this controversy might be due to EMT being a transient, reversible process occurring during the course o.
