The cytoskeleton regulatory protein hMena (ENAH) is overexpressed in human benign breast lesions with high risk of transformation and human epidermal growth factor receptor-2-positive/hormonal receptor-negative tumors.

PURPOSE: hMena (ENAH), a cytoskeleton regulatory protein involved in the regulation of cell motility and adhesion, is overexpressed in breast cancer. The aim of this study was to define at what stage of breast carcinogenesis hMena is overexpressed and to correlate hMena overexpression with established prognostic factors in breast cancer, focusing on human epidermal growth factor receptor-2 (HER-2). EXPERIMENTAL DESIGN: hMena expression was assessed immunohistochemically in a prospective cohort of cases (n = 360) encompassing a highly representative spectrum of benign breast diseases associated with different risk of transformation, in situ, invasive, and metastatic tumors. Correlations with conventional pathologic and prognostic variables, such as proliferation index, hormonal receptor status, and HER-2 overexpression, were also evaluated. In vitro experiments were done to study the effect of neuregulin-1 and Herceptin treatments on hMena expression. RESULTS: hMena protein is undetectable in normal breast and is weakly expressed in a small percentage of low-risk benign diseases (9%), but displays a progressive and significant increase of positivity in benign lesions at higher risk of transformation (slightly increased risk 43%; moderate increased risk 67%), in in situ (72%), invasive (93%), and metastatic breast cancer (91%). A significant direct correlation with tumor size (P = 0.04), proliferation index (P < 0.0001), and HER-2 overexpression (P < 0.0001) and an inverse relationship with estrogen (P = 0.036) and progesterone receptors (P = 0.001) are found in invasive carcinomas. In vitro experiments show that neuregulin-1 up-regulates, whereas Herceptin down-regulates, hMena expression. CONCLUSIONS: Our data provide new insights into the relevance of actin-binding proteins in human breast carcinogenesis and indicate hMena overexpression as a surrogate indicator in breast disease management.     

Overexpression of the stathmin gene in a subset of human breast cancer.

Stathmin is a highly conserved cytosolic phosphoprotein that destabilizes microtubules. Stathmin, which has been proposed as a relay protein integrating diverse cell signalling pathways, acts in vitro as a tubulin-sequestering protein, and its activity is dramatically reduced by phosphorylation. Interestingly, stathmin expression and phosphorylation are regulated during the control of cell growth and differentiation, and there is much evidence suggesting that in vivo stathmin plays a role in the control of microtubule dynamics during mitosis. Stathmin may thus be considered as one of the key regulators of cell division. We examined 50 human primary breast tumours for stathmin mRNA and protein expression and screened for abnormalities in the chromosome region harbouring the stathmin gene. Overexpression of stathmin was found in 15 tumours (30%). At the present stage, no clear correlation emerged between stathmin expression and several prognosis markers. Interestingly, perfect matching was observed between stathmin mRNA overexpression, protein overexpression and strong staining for stathmin on paraffin-embedded tumour sections when specimens were available. Furthermore, a tentative link between loss of heterozygosity (LOH) in the 1p32-1pter region and stathmin overexpression was observed. Our results suggest that stathmin might play a role in breast carcinogenesis and that stathmin-overexpressing tumours may represent a new subtype of breast cancer.     

Overexpression of cyclinD1 predicts for poor prognosis in estrogen receptor-negative breast cancer patients

CyclinD1 plays a critical role in regulating cell cycle progression. CyclinD1 mRNA and protein are overexpressed in approximately 50% of primary breast cancer cases. However, its clinical significance as a predictive factor remains unclear. One hundred and seventy-three female patients diagnosed with invasive ductal carcinoma who had undergone a mastectomy (161 patients) or breast-conserving surgery (12 patients) were followed up for 6-119 months (median 86 months) postoperatively. Immunoreactivity for monoclonal anti-cyclinD1 antibody (clone DCS-6) with paraffin-embedded carcinoma tissues was investigated using a labeled streptavidin-biotin method. Overexpression of cyclinD1 was found in 42% (73 of 173), and strongly correlated with estrogen receptor (ER) expression (p < 0.000001). Univariate analysis revealed no association between overexpression of cyclinD1 and overall survival or relapse-free survival in all patient groups. However, in the ER-negative subgroup (n = 75), overexpression of cyclinD1 was significantly correlated with shorter overall survival (p = 0.018) and relapse-free survival (p = 0.014) as well as the lymph node status and tumor size. In contrast, there were no significant associations between overexpression of cyclinD1 and clinical outcome in the ER-positive subgroup. According to Cox's multivariate analysis in the ER-negative subgroup, overexpression of cyclinD1 had the most significant effect on overall survival (p = 0.02) and relapse-free survival (p = 0.0058), followed by nodal status and histologic grade. These findings suggest that overexpression of cyclinD1 is an independent prognostic indicator in ER-negative breast cancer patients.     

Overexpression of c-erbB2 is an independent marker of resistance to endocrine therapy in advanced breast cancer

The present study investigated the interaction between c-erbB2 overexpression and the response to first-line endocrine therapy in patients with advanced breast cancer. The primary tumours of 241 patients who were treated at first relapse with endocrine therapy were assessed for overexpression of c-erbB2 by immunohistochemistry. c-erbB2 was overexpressed in 76 (32%) of primary breast cancers and did not correlate with any other prognostic factor. The overall response to treatment and time to progression were significantly lower in patients with c-erbB2-positive tumours compared to those that were c-erbB2-negative (38% vs 56%, P = 0.02; and 4.1 months vs 8.7 months, P < 0.001, respectively). In multivariate analysis, c-erbB2 status was the most significant predictive factor for a short time to progression (P = 0.0009). In patients with ER-positive primary tumours treated at relapse with tamoxifen (n = 170), overexpression of c-erbB2 was associated with a significantly shorter time to progression (5.5 months vs 11.2 months, P < 0.001). In conclusion, overexpression of c-erbB2 in the primary tumour is an independent marker of relative resistance to first-line endocrine therapy in patients with advanced breast cancer. In patients with ER-positive primary tumours, the overexpression of c-erbB2 defines a subgroup less likely to respond to endocrine therapy.     

LRP16基因在乳腺癌组织中的表达及其临床意义

背景与目的:既往研究表明雌激素通过其受体!直接上调LRP16的表达,LRP16基因的高表达促进乳腺癌细胞的增殖。本研究旨在探讨LRP16基因在乳腺癌组织中的表达状况及其与临床病理特征的关系。方法:收集52例乳腺癌组织及其配对癌旁组织,Northernblot与半定量RT-PCR法分别检测22例和30例标本中LRP16mRNA水平。免疫组化法检测肿瘤组织中雌激素受体(ER)、孕激素受体(PR)及Ki-67的表达情况。结果:Northernblot检测结果表明,22例癌组织LRP16mRNA的表达较癌旁组织高2倍的有9例,高表达率为40.9%(9/22)。高表达LRP16的9例中有7例ER阳性,8例PR阳性;而非高表达13例中ER阳性6例,PR阳性5例,两组ER与PR阳性率均有显著性差异(P<0.05)。LRP16高表达的9例中只有1例PR和ER同时阴性,而非高表达的13例中有7例。22例患者中,13例肿瘤直径3.0～4.5cm,其中LRP16基因高表达组占8例;有腋窝淋巴结转移的12例中8例LRP16高表达。8例高表达Ki-67患者中6例LRP16高表达。半定量RT-PCR检测结果表明,30例肿瘤标本中9例(30.0%)LRP16mRNA的表达水平明显高于癌旁组织,9例LRP16高表达者ER、PR均阳性,Ki-67高表达,且瘤体直径均大于3.5cm,均有腋窝淋巴结转移,与非高表达组比较差异有显著性(P<0.05)。结论:LRP16基因表达水平与ER/PR阳性率、细胞增殖活性、肿瘤直径、远处淋巴结转移密切相关,提示LRP16基因可能参与促进乳腺癌的增殖与转移。     

Bcl-B expression in human epithelial and nonepithelial malignancies.

PURPOSE: Apoptosis plays an important role in neoplastic processes. Bcl-B is an antiapoptotic Bcl-2 family member, which is known to change its phenotype upon binding to Nur77/TR3. The expression pattern of this protein in human malignancies has not been reported. EXPERIMENTAL DESIGN: We investigated Bcl-B expression in normal human tissues and several types of human epithelial and nonepithelial malignancy by immunohistochemistry, correlating results with tumor stage, histologic grade, and patient survival. RESULTS: Bcl-B protein was strongly expressed in all normal plasma cells but found in only 18% of multiple myelomas (n = 133). Bcl-B immunostaining was also present in normal germinal center centroblasts and centrocytes and in approximately half of diffuse large B-cell lymphoma (n = 48) specimens, whereas follicular lymphomas (n = 57) did not contain Bcl-B. In breast (n = 119), prostate (n = 66), gastric (n = 180), and colorectal (n = 106) adenocarcinomas, as well as in non-small cell lung cancers (n = 82), tumor-specific overexpression of Bcl-B was observed. Bcl-B expression was associated with variables of poor prognosis, such as high tumor grade in breast cancer (P = 0.009), microsatellite stability (P = 0.0002), and left-sided anatomic location (P = 0.02) of colorectal cancers, as well as with greater incidence of death from prostate cancer (P = 0.005) and shorter survival of patients with small cell lung cancer (P = 0.009). Conversely, although overexpressed in many gastric cancers, Bcl-B tended to correlate with better outcome (P = 0.01) and more differentiated tumor histology (P < 0.0001). CONCLUSIONS: Tumor-specific alterations in Bcl-B expression may define subsets of nonepithelial and epithelial neoplasms with distinct clinical behaviors.     

Triple-negative breast cancer types exhibit a distinct poor clinical characteristic in lymph node-negative Chinese patients

Comparative studies on the clinical features and outcomes of triple-negative subgroups to human epidermal growth factor receptor-2 (HER-2) overexpression, and luminal A and B subgroups in lymph node-negative breast cancer patients, are important to correctly evaluate clinical prognosis. A total of 1132 Chinese breast cancer patients were enrolled in a retrospective analysis. We characterized and identified prognostic information in the triple-negative subgroup [estrogen receptor (ER)-, progesterone receptor (PR)- and HER-2-negative] and compared that to HER-2 overexpression, and the luminal A and B subgroups. By using immunohistochemical staining, the triple-negative subgroup showed 17% (193/1132) in the whole group. However, HER-2 overexpression, and the luminal A and B subgroups were 11.2, 47.9 and 23.9%, respectively. Tumors in the triple-negative subgroup showed a higher histological grade (P=0.025) and lower invasive ductal carcinoma (P=0.007), compared to the three subgroups. More patients in the luminal A subgroup had received adjuvant chemotherapy (P=0.007). The difference of disease-free survival rates among the four subgroups was significant (P=0.0001). The P-value for overall survival was 0.0598. No significant difference among the four subgroups in lymph node-positive and non-chemotherapy breast cancers was found. From our data the poor clinical outcomes were independent of age, histological grade, tumor size, lymph nodal status, chemotherapy and clinical stages. Our data suggest that the triple-negative subgroup exhibits a distinct poor clinical outcome, especially in lymph node-negative Chinese breast cancer patients.     

长链非编码RNA STMN1P2在乳腺癌中的作用及机制研究

背景与目的:长链非编码RNA(long non-coding RNA,lncRNA)在肿瘤进展中发挥重要调控作用,我们的前期研究通过lncRNA表达谱芯片筛选发现,微管不稳定蛋白1假基因2(stathmin 1 pseudogene 2,STMN1P2)在乳腺癌中高表达,但其生物学功能以及在乳腺癌中的作用尚未见报道.探...     

Effect of stathmin on the sensitivity to antimicrotubule drugs in human breast cancer

Stathmin is a p53-regulated protein known to influence microtubule dynamics. Because several chemotherapeutic agents used to treat breast cancer alter the dynamic equilibrium of tubulin polymerization, stathmin may play an important role in determining the sensitivity to these drugs. Therefore, we evaluated the effect of stathmin expression on the action of taxanes and Vinca alkaloids using a panel of human breast cancer cell lines. Cell lines harboring mutant p53 expressed high levels of stathmin. Two cell lines with different levels of endogenous stathmin expression and isogenic-paired cell lines transfected to overexpress stathmin were used to determine whether or not stathmin modulated the sensitivity to drugs. Overexpression of stathmin decreased polymerization of microtubules, markedly decreased binding of paclitaxel, and increased binding of vinblastine. Stathmin overexpression decreased sensitivity to paclitaxel and, to a lesser extent, to vinblastine. In contrast, stathmin content had no significant effect on the sensitivity to chemotherapeutic drugs that do not target microtubules. Cell lines overexpressing stathmin were more likely to enter G(2) but less likely to enter mitosis as determined by fluorescence-activated cell sorting and mitotic index. This effect was magnified when stathmin-overexpressing cells were treated with vinblastine as measured by the detection of proteins phosphorylated in early mitosis. These data suggest that the action of antimicrotubule drugs can be affected by stathmin in at least two ways: (a) altered drug binding; and (b) growth arrest at the G(2) to M boundary. Mutant p53 breast cancers exhibiting high levels of stathmin may be resistant to antimicrotubule agents.     

Overexpression of Cripto and its prognostic significance in breast cancer: a study with long-term survival.

INTRODUCTION: Cripto is a founding member of the EGF-CFC family, and plays an important role in tumourigenesis, tumour cell proliferation and migration. We aimed to determine the significance of Cripto expression on the survival of patients with breast cancer. METHODS: Immunohistochemical detection of Cripto was performed by using mAb C13 on 120 formalin-fixed paraffin-embedded breast tumour specimens in tissue microarrays. This cohort comprises a series of 120 patients with primary operable breast cancer diagnosed between 1989 and 1995, retrieved from the Concord Repatriation General Hospital breast carcinoma database. RESULTS: Using a cutoff value of 80%, Cripto overexpressed in 57 of the 120 (47.5%) patients. We found significant associations between overexpression of Cripto and the Nottingham Prognostic Index (NPI, p<0.01), histological grade (p<0.01), pathological tumour type (p=0.04), PR (p=0.02) as well as Ki-67 (p=0.02). Univariate analysis reveals that there is a significant correlation between overexpression of Cripto and survival (p=0.0003). Cox regression analysis indicates that the overexpression of Cripto is an independent prognostic factor in breast cancer (HR 2.79, 95%CI 1.20-6.50). CONCLUSION: The unique epitope recognized by mAb C13 is overexpressed on breast tumour tissues. In this series of invasive breast cancers, overexpression of Cripto was more often found in high grade and poor prognosis tumours compared to low grade and good prognosis breast cancers. Moreover, overexpression of Cripto was significantly associated with decreased patient survival.     

Expression of HER2 and its association with AP-2 in breast cancer

The aim of the study was to investigate the relationship between the expression of human epidermal growth factor receptor 2 (HER2) and activator protein 2 (AP-2), as well as the prognostic significance of HER2 in breast cancer. HER2 and AP-2 expressions were immunohistochemically (IHC) analysed in a large prospective, consecutive series of 425 breast cancer patients diagnosed and treated between 1990 and 1995 at the Kuopio University Hospital, Kuopio, Finland. In a subset of patients (n = 71), the gene amplification status was examined by using a chromogenic in situ hybridisation (CISH) analysis. Expression of HER2 was studied in relation to AP-2, clinicopathological parameters and patients' survival. Pathological membranous overexpression of the HER2 receptor was seen in 13% of the carcinomas, which was related both to gene amplification (78% of the cases) and high nuclear expression of AP-2 (67%, P = 0.007). HER2-positivity was most often seen in carcinomas having both high nuclear and high cytoplasmic AP-2 expression (P < 0.001). In the univariate survival analyses HER2-positivity predicted a shorter recurrence-free survival (RFS) (P < 0.0001) and a shorter breast cancer-related survival (BCRS) (P = 0.0063) in the whole patient group, as well as in the subgroup of node-negative patients. In the node-positive patients, HER2-positivity predicted only a shorter RFS. Combined expression of HER2 and nuclear AP-2 resulted in the separation of four groups with different prognoses, the best prognosis being for patients in the HER2-/AP-2+ group and the worse prognosis for those in the HER2+/AP-2- group. In the multivariate survival analyses, HER2-positivity independently predicted a shorter RFS in the whole patient group (P = 0.0067), as well as in the subgroup of node-positive patients (P = 0.0209). In conclusion, pathological membranous overexpression of the HER2 receptor in breast cancer is related both to gene amplification and a high AP-2 expression. Combining HER2 and AP-2 expressions may provide valuable information on the prognosis of breast cancer patients.     

Clinical significance of CD151 overexpression in subtypes of invasive breast cancer

Background:

CD151 is a member of the tetraspanin family, which interacts with laminin-binding integrins and other tetraspanins. This protein is implicated in motility, invasion, and metastasis of cancer cells, but the prevalence of CD151 expression in subtypes of breast cancers and its influence on clinical outcome remains to be evaluated.

Methods and results:

The immunohistochemistry-based tissue microarray analysis showed that 127 (14.3%) cases overexpressed CD151 among 886 breast cancer patients. CD151 overexpression was found to be significantly associated with larger tumour size, higher nodal stage, advanced stage, absence of oestrogen receptor and progesterone receptor, and human epidermal growth factor receptor 2 overexpression. CD151 overexpression resulted in poorer overall survival (OS) (P<0.001) and disease-free survival (P=0.02), and stage II and III patients with CD151 overexpression demonstrated substantially poorer OS (P=0.0474 and 0.0169). In the five subtypes analyses, CD151 overexpression retained its adverse impact on OS in the Luminal A (P=0.0105) and quintuple-negative breast cancer (QNBC) subtypes, one subgroup of triple-negative breast cancer (P=0.0170). Multivariate analysis that included stage, subtype, and adjuvant chemotherapy showed that CD151 overexpression was independently associated with poor OS in invasive breast cancer.

Conclusion:

CD151 overexpression may be a potential molecular therapeutic target for breast cancer, especially in QNBC subtype and more advanced stages of breast cancer.     

Overexpression of the anti-adhesin podocalyxin is an independent predictor of breast cancer progression

Podocalyxin is a CD34-related cell surface molecule with anti-adhesive qualities. We probed a tissue microarray (n = 272) linked to long-term outcome data and found that podocalyxin was highly overexpressed in a distinct subset of invasive breast carcinomas (n = 15; 6%). Univariate disease-specific (P < 0.01) and multivariate regression (P < 0.0005) analyses indicated that this overexpression is an independent indicator of poor outcome. Forced podocalyxin expression perturbed cell junctions between MCF-7 breast carcinoma cells, and it caused cell shedding from confluent monolayers. Therefore, podocalyxin overexpression is a novel predictor of breast cancer progression that may contribute to the process by perturbing tumor cell adhesion.