Assessment of c-erbB2 and vascular endothelial growth factor mRNA expression in fine-needle aspirates from early breast carcinomas: pre-operative determination of malignant potential

S100A14, a member of the EF-hand calcium-binding proteins, is overexpressed in breast cancer and acts as a modulator of HER2 signaling

HER2 is overexpressed in 20–25% of breast cancers. Overexpression of HER2 is an adverse prognostic factor and correlates with decreased patient survival. HER2 stimulates breast tumorigenesis via a number of intracellular signaling molecules, including PI3K/AKT and MAPK/ERK.S100A14,one member of the S100 protein family, is significantly associated with outcome of breast cancer patients. Here, for the first time, we show that S100A14 and HER2 are coexpressed in invasive breast cancer specimens,andthere is a significant correlation between the expression levels of the two proteins by immunohistochemistry. S100A14 and HER2 are colocalized in plasma membrane of breast cancer tissue cells and breast cancer cell lines BT474 and SK-BR3. We demonstrate that S100A14 binds directly to HER2 by co-immunoprecipitation and pull-down assays. Further study shows that residues 956–1154 of the HER2 intracellular domain and residue 83 of S100A14 are essential for the two proteins binding.Moreover,we observe a decrease of HER2 phosphorylation, downstream signaling, and HER2-stimulated cell proliferation in S100A14-silenced MCF-7, BT474, and SK-BR3 cells. Our findings suggest that S100A14 functions as a modulator of HER2 signaling and provide mechanistic evidence for its role in breast cancer progression.

Distribution of GPR30, a seven membrane-spanning estrogen receptor, in primary breast cancer and its association with clinicopathologic determinants of tumor progression

PURPOSE

The seven transmembrane receptor, GPR30, is linked to estrogen binding and heparan-bound epidermal growth factor release. Here, the significance of GPR30 in human breast cancer was evaluated by comparing its relationship to steroid hormone receptor expression and tumor progression variables.

EXPERIMENTAL DESIGN

Immunohistochemical analysis of a National Cancer Institute-sponsored tumor collection comprised of 361 breast carcinomas obtained at first diagnosis (321 invasive and 40 intraductal tumors). Biopsies from 12 reduction mammoplasties served as controls. The distribution pattern of GPR30, estrogen receptor (ER), and progesterone receptor (PR) was correlated with clinicopathologic variables obtained at diagnosis.

RESULTS

GPR30, ER, and PR were positive in all 12 normal controls. In contrast, GPR30 expression varied in breast tumors, in which 62% (199 of 321) of invasive tumors and 42% (17 of 40) of intraductal tumors were positive. Codistribution of ER and GPR30 was measured in 43% (139 of 321) of invasive breast tumors, whereas both receptors were lacking (ER-GPR30-) in 19% (61 of 321) of the tumors analyzed, indicating a significant association between ER and GPR30 (P<0.05). The coexpression of PR and ER did not influence GPR30 expression, yet coexpression of GPR30 and ER was linked to PR positivity. Unlike ER, which varied inversely with HER-2/neu and tumor size, GPR30 positively associated with HER-2/neu and tumor size. In addition, GPR30 showed a positive association with metastasis (P=0.014; odds ratio, 1.9).

CONCLUSIONS

GPR30 and ER exhibited distinct patterns of association with breast tumor progression variables, including HER-2/neu, tumor size, and metastatic disease. Thus, these results support the hypothesis that GPR30 and ER have an independent influence on estrogen responsiveness in breast carcinoma.

Isolation by size of epithelial tumor cells in peripheral blood of patients with breast cancer: correlation with real-time reverse transcriptase–polymerase chain reaction results and feasibility of molecular analysis by laser microdissection

The aim of this study is the counting and the immunomorphological and molecular characterization of circulating tumor cells (CTCs) by the isolation by size of epithelial tumor cells (ISET) method in the peripheral blood of patients with breast cancer. An evaluation of the method's ability to reveal the presence of occult carcinoma cells in blood of a patient with breast cancer was performed and the results compared with those obtained by quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay for the evaluation of cytokeratin-19 (CK-19) mRNA expression. The feasibility of molecular analysis of CTCs after laser microdissection of filters used in ISET was illustrated, referring to HER-2 amplification. Blood samples drawn from 44 patients with breast cancer were preoperatively analyzed by ISET. From the same samples, total RNA was extracted and submitted to quantitative real-time RT-PCR for the detection of CK-19 mRNA-positive cells using TaqMan technology. HER-2 amplification was measured by real-time RT-PCR on DNA extracted from cells recovered by laser microdissection from 7 selected ISET-positive filters. Of 44 samples, 12 (27%) showed the presence of epithelial cells on the filter (mean +/- SE: 8.5 +/- 2.4 cells per milliliter of blood). A statistically significant agreement (P = .001) was observed between real-time RT-PCR results and those obtained by ISET. With regard to HER-2 amplification, a good correspondence was found between the results obtained from microdissected CTCs and those obtained using DNA extracted from the primary tumor (R = 0.918; P < .01), as well as the immunohistochemistry results. The ISET method allows for the collection of breast carcinoma cells by filtration despite their smaller dimension relative to other carcinoma cell types. The sensitivity and specificity of the method is comparable with those obtained using the quantitative real-time RT-PCR assay for the evaluation of CK-19 mRNA expression. Moreover, the laser microdissection technique allows for the recovery of nucleic acids for further molecular analysis and CTC characterization.

Evaluation of P53 and BAX gene expression and induction of apoptosis and necrosis by the cis-Pt(II) complex of 3-aminoflavone in comparison with cis-diamminedichloroplatinum(II) (cis-DDP) in human lymphocytes

Currently cis-diamminedichloroplatinum(II) (cis-DDP) is one of the most commonly applied compounds in chemotherapy of many types of cancer. However, a drawback is that its effectiveness presents with many side effects. Therefore, human normal lymphocytes were chosen as a model system to study cis-bis(3-aminoflavone)dichloroplatinum(II) (the cis-Pt(II) complex of 3-aminoflavone) in comparison with cis-DDP. We examined the effect of both tested compounds on cell viability and induction of apoptosis and necrosis. Trypan blue and acridine orange/ethidium bromide staining were carried out, as well as quantitative analysis of the apoptotic signal of P53 and BAX induction caused by the cis-Pt(II) complex of 3-aminoflavone in comparison with cis-DDP. cis-DDP induced a decrease of cell viability and led to a higher increase in necrosis and apoptosis than did the cis-Pt(II) complex of 3-aminoflavone. Moreover, at the molecular level cis-DDP increased P53 and BAX expression in comparison with the other tested compound. The cis-Pt(II) complex of 3-aminoflavone showed a weaker genotoxic effect in normal lymphocytes in comparison with cis-DDP, which was a stronger inducer of apoptosis and necrosis.

CCR7 and CXCR4 as novel biomarkers predicting axillary lymph node metastasis in T1 breast cancer

PURPOSE

The chemokine receptors CCR7 and CXCR4 have been shown to play an important role in cancer metastasis. We therefore studied the differential expression of CCR7 and CXCR4, along with that of the biomarker HER2-neu, to evaluate whether these biomarkers could predict axillary lymph node metastasis in breast cancer.

EXPERIMENTAL DESIGN

Biomarker expression levels were evaluated using paraffin-embedded tissue sections of lymph node-negative (n = 99) and lymph node-positive (n = 98) T1 breast cancer by immunohistochemical staining.

RESULTS

Lymph node-positive tumors showed higher rates of high cytoplasmic CCR7 staining (21.5% versus 8.5%, P = 0.013) and HER2-neu overexpression (21.5% versus 9.3%, P = 0.019) than did lymph node-negative tumors. Similarly, high cytoplasmic CXCR4 expression occurred more commonly in lymph node-positive tumors (11.2% versus 5.1%, P = 0.113). In contrast, predominantly nuclear CXCR4 staining was more likely to be found in lymph node-negative tumors (54.5% versus 37.8%, P = 0.018). Furthermore, cytoplasmic CXCR4 coexpressed with HER2-neu was the only factor associated with involvement of four or more lymph nodes (16.7% versus 1.2%, P = 0.04) among lymph node-positive tumors. When all three biomarkers (CCR7, CXCR4, HER2-neu) were utilized together, 50.0% of lymph node-positive tumors highly expressed one of these biomarkers compared with 18.8% of the lymph node-negative tumors (P < 0.0001).

CONCLUSIONS

Our results suggest that the chemokine receptor CCR7 is a novel biomarker that can predict lymph node metastases in breast cancer. Utilization of additional markers, such as CXCR4 and HER2-neu, further improves the prediction of the presence and extent of lymph node involvement.

Enhanced P53 and BAX gene expression and apoptosis in A549 cells by cis-Pt(II) complex of 3-aminoflavone in comparison with cis-DDP

Lung cancer remains one of the most common causes of cancer-related death worldwide. Approximately 80% is histologically non-small cell lung carcinoma (NSCLC) and in about 70% of patients it is an unresectable type. Clinical studies indicated that application of platinum derivatives caused good results and combinations of platinum with other agents could improve median survivals. In view of the central problem of sufficient efficiency of drugs in chemotherapy, efforts have focused on the development of alternative platinum-based analogues that can be more effective in cancer treatment. cis-bis(3-aminoflavone)dichloroplatinum(II) (cis-Pt(II) complex of 3-aminoflavone) represents a novel class of platinum-based potential antitumour agents. In order to evaluate the degree of apoptosis, acridine orange/ethidium bromide and Hoechst 33258/propidum iodide double staining as well as RT-PCR (P53 and BAX expression evaluation) were used in lung cancer cell line A549 after treatment with this compound in comparison with cis-diamminedichloroplatinum(II) (cis-DDP). Apoptotic cells at early and late stages and also necrotic ones were observed after usage of cis-Pt(II) complex of 3-aminoflavone and the percentage of these cells outnumbered the values obtained after cis-DDP application. The former compound induced a higher percentage of P53 and BAX expression in A549 cells in comparison with the latter one. Results indicate the beneficial properties of cis-Pt(II) complex of 3-aminoflavone as a potential antitumor drug.

Constitutive and inducible expression and regulation of vascular endothelial growth factor

Vascular endothelial growth factor (VEGF), which was originally discovered as vascular permeability factor, is critical to human cancer angiogenesis through its potent functions as a stimulator of endothelial cell survival, mitogenesis, migration, differentiation and self-assembly, as well as vascular permeability, immunosuppression and mobilization of endothelial progenitor cells from the bone marrow into the peripheral circulation. Genetic alterations and a chaotic tumor microenvironment, such as hypoxia, acidosis, free radicals, and cytokines, are clearly attributed to numerous abnormalities in the expression and signaling of VEGF and its receptors. These perturbations confer a tremendous survival and growth advantage to vascular endothelial cells as manifested by exuberant tumor angiogenesis and a consequent malignant phenotype. Understanding the regulatory mechanisms of both inducible and constitutive VEGF expression will be crucial in designing effective therapeutic strategies targeting VEGF to control tumor growth and metastasis. In this review, molecular regulation of VEGF expression in tumor cells is discussed.

Molecular detection of micrometastatic breast cancer in histopathology-negative axillary lymph nodes correlates with traditional predictors of prognosis: an interim analysis of a prospective multi-institutional cohort study

OBJECTIVE

We sought to establish the clinical relevance of micrometastatic disease detected by reverse transcription polymerase chain reaction (RT-PCR) in axillary lymph nodes (ALN) of breast cancer patients.

BACKGROUND

The presence of ALN metastases remains one of the most valuable prognostic indicators in women with breast cancer. However, the clinical relevance of molecular detection of micrometastatic breast cancer in sentinel lymph nodes (SLN) and nonsentinel ALN has not been established.

METHODS

Four hundred eighty-nine patients with T1-T3 primary breast cancers were analyzed in a prospective, multi-institutional cohort study. ALN were analyzed by standard histopathology (H&E staining) and by multimarker, real-time RT-PCR analysis (mam, mamB, muc1, CEA, PSE, CK19, and PIP) designed to detect breast cancer micrometastases.

RESULTS

A positive marker signal was observed in 126 (87%) of 145 subjects with pathology-positive ALN, and in 112 (33%) of 344 subjects with pathology-negative ALN. In subjects with pathology-negative ALN, a positive marker signal was significantly associated with traditional indicators of prognosis, such as histologic grade (P = 0.0255) and St. Gallen risk category (P = 0.022). Mammaglobin was the most informative marker in the panel.

CONCLUSION

This is the first report to show that overexpression of breast cancer-associated genes in breast cancer subjects with pathology-negative ALN correlates with traditional indicators of disease prognosis. These interim results provide strong evidence that molecular markers could serve as valid surrogates for the detection of occult micrometastases in ALN. Correlation of real-time RT-PCR analyses with disease-free survival in this patient cohort will help to define the clinical relevance of micrometastatic disease in this patient population.

The molecular detection of micrometastatic breast cancer

BACKGROUND

The rapid evolution of molecular technology and novel markers provides the opportunity to establish a more effective means to detect micrometastatic breast cancer. Given the controversies concerning application and clinical relevance, this review critically evaluates the current status of these molecular staging technologies.

DATA SOURCES

Breast cancer literature addressing (1). molecular detection methodologies (immunohistochemistry, reverse transcriptase polymerase chain reaction, and microarray analysis); (2). specific tissue applications such as lymph nodes, bone marrow aspirate, and peripheral blood; (3). expert commentary concerning the clinical applications and pitfalls of these technologies; and (4). recent data from our molecular diagnostics laboratory.

CONCLUSIONS

Molecular detection technologies such as reverse transcriptase polymerase chain reaction and microarray analyses are being developed that will likely have future application as cancer diagnostics. Further work is needed to establish assays that are validated by prospective clinical studies. Early identification of clinically relevant disease could lead to new treatment or staging approaches for breast cancer.

Quantitative real-time RT-PCR detection of breast cancer micrometastasis using a multigene marker panel

Real-time RT-PCR is a relatively new technology that uses an online fluorescence detection system to determine gene expression levels. It has the potential to significantly improve detection of breast cancer metastasis by virtue of its exquisite sensitivity, high throughput capacity and quantitative readout system. To assess the utility of this technology in breast cancer staging, we determined the relative expression levels of 12 cancer-associated genes (mam, PIP, mamB, CEA, CK19, VEGF, erbB2, muc1, c-myc, p97, vim and Ki67) in 51 negative-control normal lymph nodes and in 17 histopathology-positive ALNs. We then performed a receiver operating characteristic (ROC) curve analysis to determine the sensitivity and specificity levels of each gene. Areas under the ROC curve indicated that the most accurate diagnostic markers were mam (99.6%), PIP (93.3%), CK19 (91.0%), mamB (87.9%), muc1 (81.5%) and CEA (79.4.0%). mam was overexpressed in 16 of 17 lymph nodes known to contain metastatic breast cancer at levels ranging from 22- to 2.8 x 10(5)-fold above normal mean expression, whereas PIP was overexpressed from 30- to 2.2 x 10(6)-fold above normal in 13 lymph nodes. Real-time RT-PCR analysis of pathology-negative LN from breast cancer patients revealed evidence of overexpression of PIP (6 nodes), mam (3 nodes) and CEA (1 node) in 8 of 21 nodes (38%). Our results provide evidence that mam, PIP, CK19, mamB, muc1 and CEA can be applied as a panel for detection of metastatic and occult micrometastatic disease.

Cell biology of lymphatic metastasis. The potential role of c-erbB oncogene signalling

Lymphatic metastases are an important indicator of the malignancy of epithelial cancers. Empirical clinical observations associating specific genetic abnormalities with tumour progression, allied with basic laboratory investigations, are providing not only improved prognostic and diagnostic opportunities, but also a detailed understanding of the molecular machinery of metastasis. One such association--between the c-erbB oncogene family and metastasis--has proved particularly instructive. Functional links between over-expression (and occasionally mutational activation) of c-erbB-1 (EGFR) and c-erbB-2 and specific phenotypes of metastatic cells have been elucidated. Activated c-erbB oncogenes potentiate tumour cell adhesion to endothelial cells and upregulate VEGF, potentially facilitating angiogenesis and vascular invasion. In addition, cells over-expressing these oncogenes frequently show aberrant cell-cell and cell-matrix interactions, mediated by changes in integrin and cadherin function. Thirdly, both EGFR and c-erbB-2 signalling can significantly upregulate specific matrix metalloproteinases, key enzymes involved in angiogenesis and invasion. Finally, c-erbB receptors linked to the actin cytoskeleton and highly expressed on invadopodia, are thought to assist cell migration. Taken together, these observations suggest that such receptors can act as "master switches" in metastasis, whose activation co-ordinately controls events normally utilised in development, now subverted by the metastatic cell. As such, they represent ideal targets for therapeutic intervention.

Breast masses with peripheral rim enhancement on dynamic contrast-enhanced MR images: correlation of MR findings with histologic features and expression of growth factors

PURPOSE

To investigate the histologic bases of rim enhancement of breast masses demonstrated on dynamic contrast material-enhanced magnetic resonance (MR) images.

MATERIALS AND METHODS

Dynamic MR images of breast lesions (invasive carcinoma, n = 29; other, n = 6) in 35 women were reviewed. In each patient, subtraction images of the dynamic contrast-enhanced study were obtained, and early and delayed rim enhancement and delayed internal enhancement were evaluated. The MR findings were correlated with the ratio of microvessel density of the peripheral to the central portion of the lesion, fibrosis, and other histologic features, including expression of vascular endothelial growth factor (VEGF) and transforming growth factor ss1.

RESULTS

Early rim enhancement was observed in 29% and delayed rim enhancement was noted in 60% of all patients. Small cancer nests, a high ratio of peripheral-to-central microvessel density, peripheral VEGF expression, and a low ratio of peripheral-to-central fibrosis were correlated with early rim enhancement. Delayed rim enhancement was correlated with a high degree of fibrosis and inflammatory changes. Delayed internal enhancement was correlated with a high degree of fibrosis.

CONCLUSION

Rim enhancement of breast lesions at MR imaging is due to a combination of angiogenesis, distribution and degree of fibrosis, expression pattern of VEGF, and various histologic features.

New paradigms for the treatment of cancer: the role of anti-angiogenesis agents

Angiogenesis, the sprouting of new blood vessels, plays a role in diverse disease states including cancer, diabetic retinopathy, age-related macular degeneration, rheumatoid arthritis, psoriasis, atherosclerosis, and restenosis. With regard to cancer, the clinical association of tumor vascularity with tumor aggressiveness has been clearly demonstrated in numerous tumor types. The observation of increased microvessel density in tumors not only serves as an independent prognostic indicator, but also suggests that anti-angiogenic therapy may be an important component of treatment regimens for cancer patients. The complexity of the angiogenic process, which involves both positive and negative regulators, provides a number of targets for therapy. Many positive regulators, including growth factor receptors, matrix metalloproteinases, and integrins, have been correlated with increased vascularity of tumors and poor prognosis for patient survival. Thus, these serve as ideal targets for anti-angiogenesis therapy. Many inhibitors of these targets are currently undergoing clinical evaluation as potential anti-cancer agents. In this article, we discuss the role of positive regulators in angiogenesis and tumor growth and describe the anti-angiogenic agents under development.