Identification of mammaglobin as a novel serum marker for breast cancer

Evaluation of Serum Mammaglobin as an Alternative Biomarker in the Diagnosis of Breast Tumors

Introduction Breast cancer is the most common cancer in women in India and accounts for 14% of all cancers in women. Rise in mortality is due to lack of awareness and proper screening. Mammography and presently available serum biomarkers have low sensitivity and specificity. In our quest to identify a better biomarker, we studied mammaglobin (MAM) in patients with breast cancer and benign breast tumors.

Aim To evaluate serum mammaglobin in breast cancer patients and compare it with benign breast tumor patients and healthy controls. To compare it with existing biomarkers serum carcinoembryonic antigen (CEA) and cancer antigen 15–3 (CA 15–3). Materials and methods: This is a cross-sectional, case–control study of 77 subjects, of which 27 were breast cancer patients, 20 benign breast tumor patients, and 30 healthy controls. Serum CEA and CA15–3 were estimated by electrochemiluminescence immunoassay (ECLIA) and mammaglobin (MAM) by enzyme-linked immunosorbent assay (ELISA).

Results Mammaglobin and CEA levels were elevated in breast cancer patients, followed by benign breast tumors when compared with controls (P < 0.000001). Mammaglobin showed 81.5% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 88.9% negative predictive value (NPV). CEA showed 88.9% sensitivity, 82.5% specificity, 77.4% PPV, and 91.7% NPV. The area under the curve was the highest for MAM (0.892), followed by CEA (0.889) and CA 15–3 (0.555). CA15–3 showed poor diagnostic efficacy. Combined receiver operating characteristic (ROC) curve of the biomarkers MAM and CEA had an AUC of 0.913.

Conclusion Mammaglobin proved to be an efficacious biomarker in diagnosing breast cancer.

Nanoscale flow cytometry for immunophenotyping and quantitating extracellular vesicles in blood plasma

Extracellular vesicles (EVs) are lipid membrane enclosed nano-sized structures released into the extracellular environment by all cell types. EV constituents include proteins, lipids and nucleic acids that reflect the cell from which they originated. The molecular profile of cancer cells is distinct as compared to healthy cells of the same tissue type, and this distinct profile should be reflected by the EVs they release. This makes EVs desirable candidates for blood-based biopsy diagnosis of cancer. EVs can be time consuming to isolate therefore, a technology that can analyze EVs in complex biological samples in a high throughput manner is in demand. Here nanoscale flow cytometry is used to analyze EVs in whole, unpurified, plasma samples from healthy individuals and breast cancer patients. A known breast cancer marker, mammaglobin-a, was evaluated as a potential candidate for expression on EVs and increased levels in breast cancer. Mammaglobin-a particles were abundantly detected in plasma by nanoscale flow cytometry but only a portion of these particles were validated as bona fide EVs. EVs could be distinguish and characterized from small protein clusters and platelets based on size, marker composition, and detergent treatment. Mammaglobin-a positive EVs were characterized and found to be CD42a/CD41-positive platelet EVs, and the number of these EVs present was dependent upon plasma preparation protocol. Different plasma preparation protocols influenced the total number of platelet EVs and mammaglobin-a was found to associate with lipid membranes in plasma. When comparing plasma samples prepared by the same protocol, mammaglobin-a positive EVs were more abundant in estrogen receptor (ER) positive as compared to ER negative breast cancer patient plasma samples. This study demonstrates the capabilities of nanoscale flow cytometry for EV and small particle analysis in whole, unpurified, plasma samples, and highlights important technical challenges that need to be addressed when developing this technology as a liquid biopsy platform.

Mammaglobin B may be a prognostic biomarker of uterine corpus endometrial cancer

Mammaglobin B, also referred to as secretoglobin family 2A member 1 (SCGB2A1), has been reported to be highly expressed in uterine corpus endometrial cancer (UCEC) compared with in the normal endometrium. However, the prognostic value of SCGB2A1 in UCEC remains unclear. The Oncomine, The Cancer Genome Atlas (TCGA) and Clinical Proteomic Tumor Analysis Consortium databases were used to explore the differential expression of SCGB2A1. Furthermore, data of patients with UCEC were downloaded from TCGA, and logistic regression analysis, survival analysis, univariate and multivariate analyses, and nomogram construction were performed to identify its prognostic value in UCEC. Additionally, gene set enrichment analysis (GSEA) was utilized to estimate the mechanisms of SCGB2A1 in UCEC. Finally, immune infiltration of SCGB2A1 in UCEC was analyzed using the Tumor Immune Estimation Resource. Decreased mRNA and protein expression levels of SCGB2A1 were significantly associated with poor prognostic clinicopathological characteristics (all P<0.05). Additionally, low expression levels of SCGB2A1 were associated with decreased survival of patients with UCEC compared with high expression levels of SCGB2A1. Furthermore, the independent prognostic value of SCGB2A1 in UCEC was identified by univariate and multivariate analyses. A nomogram based on 6 variables, including SCGB2A1 expression, was developed for the estimation of the 1-, 3-, and 5-year survival probability in UCEC. Additionally, GSEA suggested that the vascular endothelial growth factor, PTEN, platelet-derived growth factor, DNA repair, KRAS signaling, and PI3K-AKT-mTOR signaling pathways were differentially enriched in the low SCGB2A1 expression phenotype. Finally, high infiltration levels of CD8+ T cells were associated with SCGB2A1 in UCEC and this was associated with prognosis. The present results indicated that SCGB2A1 may be a promising independent prognostic factor in UCEC. These signaling pathways may be crucial for the regulation of UCEC via SCGB2A1.

Electrochemical Nanobiosensors for Detection of Breast Cancer Biomarkers

This comprehensive review paper describes recent advances made in the field of electrochemical nanobiosensors for the detection of breast cancer (BC) biomarkers such as specific genes, microRNA, proteins, circulating tumor cells, BC cell lines, and exosomes or exosome-derived biomarkers. Besides the description of key functional characteristics of electrochemical nanobiosensors, the reader can find basic statistic information about BC incidence and mortality, breast pathology, and current clinically used BC biomarkers. The final part of the review is focused on challenges that need to be addressed in order to apply electrochemical nanobiosensors in a clinical practice.

Over-expression of mammaglobin-B in canine mammary tumors

Background

Mammaglobin, a member of secretoglobin family has been recognized as a breast cancer associated protein. Though the exact function of the protein is not fully known, its expression has been reported to be upregulated in human breast cancer.We focused on studying the expression of mammaglobin-B gene and protein in canine mammary tumor (CMT) tissue. Expression of mammaglobin-B mRNA and protein were assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC), respectively.

Results

High levels of mammaglobin-B mRNA expression (6.663 ± 0.841times) was observed in CMT as compared to age and breed matched healthy controls. Further, expression of mammaglobin-B protein was detected in paraffin-embedded mammary tumor tissues from the same subjects by IHC. Mammaglobin-B protein was overexpressed only in 6.67% of healthy mammary glands while, a high level of its expression was scored in 76.7% of the CMT subjects. Moreover, no significant differences in terms of IHC score and qRT-PCR score with respect to CMT histotypes or tumor grades were observed, indicating that mammaglobin-B over-expression occurred irrespective of CMT types or grades.

Conclusion

Overall, significantly increased expression of mammaglobin-B protein was found in CMTs with respect to healthy mammary glands, which positively correlates to its transcript. These findings suggest that overexpression of mammaglobin-B is associated with tumors of canine mammary glands.

[Mammaglobin in peripheral blood and tumor in breast cancer patients]

Currently, no molecular biological markers do exist for early diagnosis of breast cancer. One of the possible candidates for the marker of early breast cancer is mammaglobin (MGB1) or SCGB2A2 (secretoglobin, family 2A, member 2), characterized by the maximal expression level in early breast cancer. Using the RT-PCR method MGB1 mRNA expression was examined in 57 tumor tissue samples and 57 samples of morphologically non-malignant tissue (MNT) of breast cancer (BC) patients. Specificity and sensitivity of the MGB1 mRNA assay in peripheral blood of BC patients was evaluated by nested PCR. 169 blood samples (from 95 BC patients, 22 from patients with benign breast tumors, 28 from patients with tumors of other localizations, and 24 samples from healthy donors) have been analyzed. MGB1 expression was significantly higher in BC tissue samples compared to MNT (p=0.0019). The maximal expression level was in the samples T1 (p=0.013), stage I BC (p=0.037), GI (p=0.0019). The MGB1 expression positively correlated with expression of estrogen (p = 0,034) and progesterone (p=0.0004) receptors. Sensitivity and specificity of the MGB1 mRNA assay in peripheral blood were 60.6% and 92.3%, respectively. Expression of MGB1 was higher in BC than MNT and it decreased during BC progression. The sensitivity and specificity of the MGB1 mRNA assay may be used as an additional diagnostic method.

Generation of monoclonal antibodies against MGA and comparison of their application in breast cancer detection by immunohistochemistry

Mammaglobin A (MGA) is an organ specific molecular biomarker for metastatic breast cancer diagnosis. However, there are still needs to develop optimal monoclonal antibodies (mAbs) to detect MGA expression in breast carcinoma by immunohistochemistry. In this study, we first generated mAbs against MGA. Then, we used epitope prediction and computer-assisted structural analysis to screen five dominant epitopes and identified mAbs against five epitopes. Further immunohistochemical analysis on 42 breast carcinoma specimens showed that MHG1152 and MGD785 had intensive staining mainly in membrane, while CHH11617, CHH995 and MJF656 had more intensive staining within the cytoplasm. MGA scoring results showed that MJF656 had the highest rate (92.8%) of positive staining among five mAbs, including higher staining intensity when compared with that of MHG1152 (p < 0.01) and CHH995 (p < 0.05) and the highest the mean percentage of cells stained among mAbs. Furthermore, we analyzed the relationship of positive staining rate by mAbs with patient clinical characteristics. The results suggest that MJF656 was able to detect MGA expression, especially in early clinical stage, low grade and lymph node metastasis-negative breast carcinoma. In conclusion, our study generated five mAbs against MGA and identified the best candidate for detection of MGA expression in breast cancer tissues.

Mammaglobin 1 promotes breast cancer malignancy and confers sensitivity to anticancer drugs

Mammaglobin 1 (MGB1), a member of the secretoglobin family, is expressed in mammary epithelial tissues and is overexpressed in most mammary carcinomas. Despite the extensive research correlating MGB1 expression profiles to breast cancer pathogenesis and disease outcome, the biological significance of MGB1 in cancer processes is still unclear. We have thus set out to conduct a functional evaluation of the molecular and cellular roles of MGB1 in breast cancer processes leading to disease progression. Using a series of breast cancer cell models with conditional MGB1 expression, we demonstrate that MGB1 promotes cancer cell malignant features. More specifically, loss of MGB1 expression resulted in a decrease of cell proliferation, soft agar spheroid formation, migration, and invasion capacities of breast cancer cells. Concomitantly, we also observed that MGB1 expression activates signaling pathways mediated by MAPK members (p38, JNK, and ERK), the focal adhesion kinase (FAK), matrix metalloproteinases (MMPs) and NFκB. Moreover, MGB1 regulates epithelial to mesenchymal (EMT) features and modulates Snail, Twist and ZEB1 expression levels. Interestingly, we also observed that expression of MGB1 confers breast cancer cell sensitivity to anticancer drug-induced apoptosis. Together, our results support a role for MGB1 in tumor malignancy in exchange for chemosensitivity. These findings provide one of the first descriptive overview of the molecular and cellular roles of MGB1 in breast cancer processes and may offer new insight to the development of therapeutic and prognostic strategies in breast cancer patients. © 2015 Wiley Periodicals, Inc.

Significance of immunohistochemistry in breast cancer

The biological characteristics of the tumour are used to estimate prognosis and select appropriate systemic therapy for patients with (breast) cancer. The advent of molecular technology has incorporated new biomarkers along with immunohistochemical and serum biomarkers. Immunohistochemical markers are often used to guide treatment decisions, to classify breast cancer into subtypes that are biologically distinct and behave differently, and both as prognostic and predictive factors. Steroid hormone receptors, markers of tumour proliferation, and factors involved in angiogenesis and apoptosis are of scientific interest. In this review we will provide information on the immunohistochemical markers used in the management of breast cancer patients using available data from the literature. We consider the utility of established immunohistochemical markers, and discuss the challenges involved in integrating novel molecular markers into clinical practice.

Significance of immunohistochemistry in breast cancer

The biological characteristics of the tumour are used to estimate prognosis and select appropriate systemic therapy for patients with (breast) cancer. The advent of molecular technology has incorporated new biomarkers along with immunohistochemical and serum biomarkers. Immunohistochemical markers are often used to guide treatment decisions, to classify breast cancer into subtypes that are biologically distinct and behave differently, and both as prognostic and predictive factors. Steroid hormone receptors, markers of tumour proliferation, and factors involved in angiogenesis and apoptosis are of scientific interest. In this review we will provide information on the immunohistochemical markers used in the management of breast cancer patients using available data from the literature. We consider the utility of established immunohistochemical markers, and discuss the challenges involved in integrating novel molecular markers into clinical practice.

Recombinant mammaglobin A adenovirus-infected dendritic cells induce mammaglobin A-specific CD8+ cytotoxic T lymphocytes against breast cancer cells in vitro

Mammaglobin A (MGBA) is a novel breast cancer-associated antigen almost exclusively over-expressed in primary and metastatic human breast cancers, making it a potential therapeutic target for breast cancer. The development of dendritic cell (DC)-induced tumor antigen specific CD8⁺ cytotoxic T lymphocytes (CTLs) may hold promise in cancer immunotherapy. In this study we constructed recombinant replication-defective adenoviral (Ad) vectors encoding MGBA and evaluated their ability to trigger anti-tumor immunity in vitro. DCs were isolated from the human peripheral blood monocyte cells (PBMCs) of two HLA-A33⁺ healthy female volunteers, and infected with adenovirus carrying MGBA cDNA (Ad-MGBA). After that, the Ad-MGBA-infected DCs were used to stimulate CD8⁺ CTLs in vitro and the latter was used for co-culture with breast cancer cell lines. The data revealed that infection with Ad-MGBA improved DC maturation and up-regulated the expression of co-stimulatory molecules and the secretion of interleukin-12 (IL-12), but down-regulated interleukin-10 (IL-10) secretion from DCs. Ad-MGBA-infected DC-stimulated CD8⁺CTLs displayed the highest cytotoxicity towards HLA-A33⁺/MGBA⁺ breast cancer MDA-MB-415 cells compared with other CD8⁺CTL populations, and compared with the cytotoxicity towards HLA-A33⁻/MGBA⁺ breast cancer HBL-100 cells and HLA-A33⁻/MGBA⁻ breast cancer MDA-MB 231 cells. In addition, Ad-MGBA-infected DC-stimulated CD8⁺ CTLs showed a high level of IFNγ secretion when stimulated with HLA-A33⁺/MGBA⁺ breast cancer MDA-MB-415 cells, but not when stimulated with HLA-A33⁻/MGBA⁺ HBL-100 and HLA-A33⁻/MGBA⁻MDA-MB-231 cells. In addition, killing of CD8⁺CTLs against breast cancer was in a major histocompability complex (MHC)-limited pattern. Finally, the data also determined the importance of TNF-α in activating DCs and T cells. These data together suggest that MGBA recombinant adenovirus-infected DCs could induce specific anti-tumor immunity against MGBA⁺ breast cancers, which could provide a novel strategy in the immunotherapy of breast cancer.

Biomarkers in the diagnosis of primary and recurrent breast cancer

Despite the widespread use of mammography for breast cancer screening, breast cancer remains the most common cause of cancer-related mortality among women worldwide. The identification of biomarkers that identify cancers when they are small, localized and most treatable is an important aim of current breast cancer research. Biomarkers need to be sensitive, specific, reproducible and easily collected from patients from readily accessible tissue or body fluids. While conventional biomarker research has focused on soluble proteins, cell markers, proteomics and DNA methylation, much progress has also been made in the field of immunobiomarkers and multiparameter gene arrays. Currently, no one biomarker has demonstrated sufficient sensitivity and reproducibility for independent clinical and commercial use. This review summarizes the current state of breast cancer biomarker research and anticipated future directions.

Mammaglobin peptide as a novel biomarker for breast cancer detection

Among the different types of tests used for cancer diagnosis, molecular tests have been increrasingly incorporated because of their ability to detect either expression or functional changes in the molecules associated with the disease. Mammaglobin is a protein found in mammary tissue and can be detected in serum. This protein has been proposed as a biomarker to diagnose breast cancer, given that patients exhibit an increased amount of the protein in serum and tumor tissue, in comparison to healthy individuals. The ELISA test was used in the present study to detect mammaglobin in blood samples from 51 breast cancer patients and 51 control individuals. Antibodies against mamaglobin were generated in rabbits by using the following synthetic peptides: A (amino acids 13 to 21), B (amino acids 31 to 39), C (amino acids 56 to 64) and a D peptide, corresponding to the protein isoform without three amino acids (59, 60 and 61 amino acids) from peptide C. All peptides were immunogenic and allowed generation of antibodies that were able to discriminate patients from controls. The best results were obtained for antiserum B, achieving the best sensitivity (86.3%) and specificity (96%).

[The diagnostic value of RNA oncomarkers in evaluation of malignant breast tumors]

The levels of the RNA oncomarkers, telomerase (hTERT), cytokeratin-19 (CK-19) and mammaglobin (MAM) have been investigated in capillary blood of female patients with mammary ductal carcinoma. The study revealed overexpression of all three factors in patients with this pathology. This overexpression was not found in healthy donors and female patients with mammary fibroadenoma. Levels of the RNA oncomarkers return to the normal level within 10 days after successful tumor resection. These results have been used for the development of diagnostic kits, which may be applicable for differential diagnostics, screening and postoperation monitoring of patients with malignant breast tumors

ABCB1/MDR1 contributes to the anticancer drug-resistant phenotype of IPH-926 human lobular breast cancer cells

Contribution of the ABCB1/MDR1/P-glycoprotein drug transporter to breast cancer resistance has been controversial. One issue is that ABCB1-dependent drug-resistance has primarily been investigated in mammary epithelial cell models technically manipulated to overexpress ABCB1, either by gene transfer using appropriate expression vectors or by chronic anticancer drug-selection. However, an unmodified human breast cancer cell line with an endogenous overexpression of ABCB1 has not been described thus far. Using Affymetrix microarray analyses, we identified an endogenous overexpression of several tumor-biologically relevant transcripts including ABCB1, BCAR4, CCL28, SCGB2A2 and PIP in IPH-926, an anticancer drug-resistant human lobular breast cancer cell line derived from a chemo-refractory mammary carcinoma patient. In a panel of twenty breast cancer cell lines examined, overexpression of ABCB1 mRNA and protein was exclusively detected in IPH-926. This was further validated using chronically in vitro drug-selected KB-V-1 cells as a widely used reference model to accurately define an ABCB1 overexpression. IPH-926 and KB-V-1 displayed a similar overexpression of ABCB1. Flow cytometric analyses showed that IPH-926 but not ABCB1-negative breast cancer cells extruded the anticancer agent doxorubicin, a classical substrate of the ABCB1 drug transporter. PSC-833 (valspodar), a selective ABCB1 inhibitor, blocked this efflux, restored apoptotic PARP cleavage and increased doxorubicin sensitivity in IPH-926 and KB-V-1. To our knowledge, IPH-926 represents the first human breast cancer cell line with a genuine, endogenous overexpression of ABCB1. IPH-926 provides evidence that ABCB1 can occasionally cause anticancer drug-resistance in breast cancer patients and offers a new tool for the evaluation of compounds to overcome drug-resistance.

Prediction of extracellular matrix proteins based on distinctive sequence and domain characteristics

Extracellular matrix (ECM) proteins are secreted to the exterior of the cell, and function as mediators between resident cells and the external environment. These proteins not only support cellular structure but also participate in diverse processes, including growth, hormonal response, homeostasis, and disease progression. Despite their importance, current knowledge of the number and functions of ECM proteins is limited. Here, we propose a computational method to predict ECM proteins. Specific features, such as ECM domain score and repetitive residues, were utilized for prediction. Based on previously employed and newly generated features, discriminatory characteristics for ECM protein categorization were determined, which significantly improved the performance of Random Forest and support vector machine (SVM) classification. We additionally predicted novel ECM proteins from non-annotated human proteins, validated with gene ontology and earlier literature. Our novel prediction method is available at biosoft.kaist.ac.kr/ecm.

One-hit effects and cancer

This perspective on Bellacosa et al. (beginning on p. 48 in this issue of the journal) discusses the important biology of microscopically normal tissues in carriers of germ-line BRCA1 or BRCA2 mutations. The work of Bellacosa et al. is an important step toward discerning which pathways may be altered when one BRCA allele is inactivated.

Fabrication and Characterization of a Surface-Acoustic-Wave Biosensor in CMOS Technology for Cancer Biomarker Detection

Design, fabrication, and characterization of a novel surface acoustic wave (SAW) biosensor in complementary metal-oxide semiconductor (CMOS) technology are introduced. The biosensor employs a streptavidin/biotin-based five-layer immunoassay for detecting a prominent breast cancer biomarker, mammoglobin (hMAM). There is a growing demand to develop a sensitive and specific assay to detect biomarkers in serum that could be used in the early detection of breast cancer, determining prognosis and monitoring therapy. CMOS-SAW devices present a viable alternative to the existing biosensor technologies by providing higher sensitivity levels and better performance at low costs. Two architectures (circular and rectangular) were developed and respective tests were presented for performance comparison. The sensitivities of the devices were analyzed primarily based on center frequency shifts. A frequency sensitivity of 8.704 pg/Hz and a mass sensitivity of 2810.25 m(2) /kg were obtained. Selectivity tests were carried out against bovine serum albumin. Experimental results indicate that it is possible to attach cancer biomarkers to functionalized CMOS-SAW sensor surfaces and selectively detect hMAM antigens with improved sensitivities, lowered costs, and increased repeatability of fabrication.

Altered gene expression in morphologically normal epithelial cells from heterozygous carriers of BRCA1 or BRCA2 mutations

We hypothesized that cells bearing a single inherited "hit" in a tumor suppressor gene express an altered mRNA repertoire that may identify targets for measures that could delay or even prevent progression to carcinoma. We report here on the transcriptomes of primary breast and ovarian epithelial cells cultured from BRCA1 and BRCA2 mutation carriers and controls. Our comparison analyses identified multiple changes in gene expression, in both tissues for both mutations, which were validated independently by real-time reverse transcription-PCR analysis. Several of the differentially expressed genes had been previously proposed as cancer markers, including mammaglobin in breast cancer and serum amyloid in ovarian cancer. These findings show that heterozygosity for a mutant tumor suppressor gene can alter the expression profiles of phenotypically normal epithelial cells in a gene-specific manner; these detectable effects of "one hit" represent early molecular changes in tumorigenesis that may serve as novel biomarkers of cancer risk and as targets for chemoprevention.

Comparative Proteomic Analysis of Plasma from Clinical Healthy Cows and Mastitic Cows

The current research presents the protein changes in plasma from healthy dairy cows and clinical mastitic cows using two-dimensional gel electrophoresis (2-DE). After staining with silver nitrate and Coomassie Blue, differential expression proteins were detected by PDQuest 7.4 software, and then subjected to ion trap mass spectrometer equipped with a Surveyor HPLC System, differential spots of protein were identified. Three protein spots that originated from preparation gels were identified to be two proteins. Overall, haptoglobin precursor was up-regulated in cows infected with clinical mastitis and could be a mastitis-associated diagnostic marker, whereas SCGB 2A1 (secretoglobin, family 2A, member 1) was down-regulated protein. Plasma protein expression patterns were changed when cows were infected with mammary gland inflammation; it suggests that analysis of differential expression protein might be useful to clarify the mechanisms involved in the pathophysiology, and find new diagnostic markers of mastitis and potential protein targets for treatment.

Mammaglobin as a potential molecular target for breast cancer drug delivery

BACKGROUND

Mammaglobin (MAM) has been used as a specific molecular marker for breast cancer diagnosis. Recently, several groups of researchers proposed a number of therapeutic strategies targeting this molecule. Some of the strategies are based upon an essential but not demonstrated hypothesis - mammaglobin is associated with the surface of breast cancer cells, which strongly disputes the therapeutic strategies.

RESULTS

We conducted a computer-based predictive analysis and identified a small fragment at the N-end of MAM as a potential transmembrane domain. We provided several evidences to demonstrate the presence of the membrane-associated MAM. We isolated the membrane protein components from known MAM positive breast cancer cells (MDA-MB361 and MDA-MB415). We showed that about 22-64% of MAM proteins, depending upon the types of the cancer cells, directly attached on the membrane of breast cancer cells, by Western blotting assays. To directly visualize the presence of the membrane-bound MAM protein, we incubated the MAM positive cancer cells with FITC labeled anti-MAM antibody, and observed clear fluorescent signals on the surface of the cells. In studying the MAM protein distribution in human breast cancer tissues, we first identified two immunostain patterns that are associated with the membrane-bound MAM: the membrane stain pattern and luminary surface stain pattern. To test whether the membrane-associated MAM can serve as a molecular target for drug delivery, we conjugated anti-MAM antibody to human low-density lipoprotein (LDL) and loaded doxorubicin (Dox) in the core of LDL. Specific binding and cytotoxicity of the MAM targeted and Dox loaded LDL was tested in the MAM positive breast cancer cells in vitro.

CONCLUSION

We first showed that some of MAM protein directly associated with the surface of breast cancer cells. The membrane-associated MAM protein may be utilized as a useful molecular marker for breast cancer targeted drug delivery.

Breast cancer screening and biomarkers

Annual screening mammograms have been shown to be cost-effective and are credited for the decline in mortality of breast cancer. New technologies including breast magnetic resonance imaging (MRI) may further improve early breast cancer detection in asymptomatic women. Serum tumor markers such as CA 15-3, carcinoembyonic antigen (CEA), and CA 27-29 are ordered in the clinic mainly for disease surveillance, and not useful for detection of localized cancer. This review will discuss blood-based markers and breast-based markers, such as nipple/ductal fluid, with an emphasis on biomarkers for early detection of breast cancer. In the future, it is likely that a combination approach to simultaneously measure multiple markers would be most successful in detecting early breast cancer. Ideally, such a biomarker panel should be able to detect breast cancer in asymptomatic patients, even in the setting of normal mammogram and physical examination results.

Study on relationship between angiogenesis and micrometastases of peripheral blood in breast cancer

PURPOSE

To investigate the relationship between microvessel density, expression of vascular endothelial growth factor A (VEGF-A) and micrometastases in peripheral blood of patients with breast cancer.

METHOD

Microvessel density (MVD) and expression of VEGF-A were detected by immunohistochemistry S-P. Nested RT-PCR was introduced to detect the expression of hMAM mRNA in peripheral blood of all cases.

RESULT

Average MVD was 28.95 +/- 6.95 microvessels/100x and positive rate of VEGF-A was 64.0% (32/50) in 50 cases with breast cancer. MVD count and expression of VEGF-A were related to tumor size, metastasis of axillary lymph nodes and clinical stages (P < 0.05), independent of age and histological classification (P > 0.05). The positive rate of hMAM mRNA in peripheral blood was 34.0% (17/50), which correlated with lymphatic metastasis and clinical stages (P < 0.05), independent of pathological category, menopause and hormone receptor (P > 0.05). MVD count and positive rate of VEGF-A in breast cancer with positive expression of hMAM mRNA was obviously higher than those without hMAM mRNA expression (chi (2) = 5.766, P = 0.032; t = 5.37, P = 0.002).

CONCLUSIONS

MVD count and positive expression of VEGF-A closely correlated to hMAM mRNA released from tumor cells in the circulation. hMAM mRNA is expected to become a valuable marker for further study on micrometastases of breast cancer.

Mammaglobin B expression in human endometrial cancer

Mammaglobin B (MGB-2) is an uteroglobin gene family member recently found highly differentially expressed in ovarian cancer by gene expression profiling. To evaluate its potential as a novel endometrial cancer biomarker, in this study we quantified and compared MGB-2 expression at messenger RNA and protein levels in endometrial tumors (endometrioid endometrial cancer [EEC]) with different grades of differentiation. MGB-2 expression was evaluated by real-time polymerase chain reaction (PCR) and immunohistochemistry (IHC) in fresh frozen biopsies and paraffin-embedded tissues derived from a total of 70 patients including 50 primary EEC and 20 normal endometria (NECs). High levels of MGB-2 gene expression were detected in 10 of 11 EEC G1 cases (91%), 16 of 17 EEC G2 cases (94%), and 6 of 22 EEC G3 cases (27%) by real-time PCR. In contrast, normal endometrial cells expressed low to negligible levels of MGB-2 by real-time PCR (P= 0.002 EEC vs NEC). Well- and moderately differentiated EECs overexpressed MGB-2 gene at significant higher levels when compared to NECs (P< 0.01). Pairwise differences between both G2 and G1 vs G3 cases for MGB-2 relative gene expression values were also statistically significant (G2 vs G3 P< 0.001, G1 vs G3 P= 0.016). MGB-2 protein expression was detected in 31 (86%) of 36 EEC and 0 of 5 atrophic NEC controls, while seven of eight (88%) of the proliferative/secretory/hyperplastic NECs focally expressed MGB-2 by IHC. MGB-2 is highly expressed in EEC, particularly in well- and moderately differentiated tumors, and may represent a novel molecular marker for EEC.

Comparative evaluation of an extensive histopathologic examination and a real-time reverse-transcription-polymerase chain reaction assay for mammaglobin and cytokeratin 19 on axillary sentinel lymph nodes of breast carcinoma patients

OBJECTIVE

To assess the accuracy of a commercially available real-time reverse-transcription-polymerase chain reaction assay for mammaglobin and cytokeratin 19 mRNAs [GeneSearch Breast Lymph Node (BLN) Assay, Veridex LLC, Warren, NJ] in the detection of axillary sentinel lymph nodes (SLNs) metastases in patients with breast carcinoma.

SUMMARY BACKGROUND DATA

Because of the lack of standardized and widely accepted protocols for a truly accurate histopathologic examination of SLN, the relative merits of alternative assays based on the identification of tumor specific mRNA markers deserve further assessment.

METHODS

: A prospective series of 293 consecutive SLNs from 293 patients was evaluated. The BLN assay results were compared with those of an extensive histopathologic examination of the entire SLNs performed on serial frozen sections cut at 40 to 50 microm intervals.

RESULTS

The BLN assay correctly identified 51 of 52 macrometastatic and 5 of 20 micrometastatic SLNs, with a sensitivity of 98.1% to detect metastases larger than 2 mm, 94.7% for metastases larger than 1 mm, and 77.8% for metastases larger than 0.2 mm. The overall concordance with histopathology was 90.8%, with specificity of 95.0%, positive predictive value of 83.6%, and negative predictive value of 92.9%. When the results were evaluated according to the occurrence of additional metastases to non-SLN in patients with histologically positive SLNs, the assay was positive in 33 (91.7%) of the 36 patients with additional metastases and in 22 (66.6%) of the 33 patients without further echelon involvement.

CONCLUSIONS

The sensitivity of the reverse-transcription -polymerase chain reaction assay is comparable to that of the histopathologic examination of the entire SLN by serial sectioning at 1.5 to 2 mm.

Use of a panel of novel genes for differentiating breast cancer from non-breast tissues

Existing serum markers for breast cancer such as CA 15-3, BR 27.29 and CEA lack sensitivity and specificity. The aim of this study was to evaluate the value of new putative breast-specific markers for differentiating breast cancer from non-breast tissues. Expression of mammaglobin A (MGA), B726P, small breast epithelial mucin (SBEM) and MUC1 was measured by RT-PCR. MGA mRNA was detected in 86/162 (60%) breast cancers but in only 1/32 (3%) non-breast tissues; B726P was detected in 44/108 (41%) breast cancers but in none of 20 non-breast tissues, while SBEM was present in 52/103 (51%) breast cancers but in only 1/26 non-breast cancer tissues. In contrast to these novel markers, the established breast cancer marker MUC1 was detected in 72/99 (73%) breast cancers and in 22/32 (59%) of non-breast tissues. Combining MGA with B726P separated breast cancer from non-breast tissue with a sensitivity of 71% and a specificity of 95% while combining MGA with SBEM differentiated breast cancer from non-breast tissues with a sensitivity of 76% and a specificity of 89%. Genes such as MGA, B726P and SBEM that are expressed relatively exclusively in breast tissue are potential new markers for breast cancer.

Clinical decision modeling system

Background

Decision analysis techniques can be applied in complex situations involving uncertainty and the consideration of multiple objectives. Classical decision modeling techniques require elicitation of too many parameter estimates and their conditional (joint) probabilities, and have not therefore been applied to the problem of identifying high-performance, cost-effective combinations of clinical options for diagnosis or treatments where many of the objectives are unknown or even unspecified.

Methods

We designed a Java-based software resource, the Clinical Decision Modeling System (CDMS), to implement Naïve Decision Modeling, and provide a use case based on published performance evaluation measures of various strategies for breast and lung cancer detection. Because cost estimates for many of the newer methods are not yet available, we assume equal cost. Our use case reveals numerous potentially high-performance combinations of clinical options for the detection of breast and lung cancer.

Results

Naïve Decision Modeling is a highly practical applied strategy which guides investigators through the process of establishing evidence-based integrative translational clinical research priorities. CDMS is not designed for clinical decision support. Inputs include performance evaluation measures and costs of various clinical options. The software finds trees with expected emergent performance characteristics and average cost per patient that meet stated filtering criteria. Key to the utility of the software is sophisticated graphical elements, including a tree browser, a receiver-operator characteristic surface plot, and a histogram of expected average cost per patient. The analysis pinpoints the potentially most relevant pairs of clinical options ('critical pairs') for which empirical estimates of conditional dependence may be critical. The assumption of independence can be tested with retrospective studies prior to the initiation of clinical trials designed to estimate clinical impact. High-performance combinations of clinical options may exist for breast and lung cancer detection.

Conclusion

The software could be found useful in simplifying the objective-driven planning of complex integrative clinical studies without requiring a multi-attribute utility function, and it could lead to efficient integrative translational clinical study designs that move beyond simple pair wise competitive studies. Collaborators, who traditionally might compete to prioritize their own individual clinical options, can use the software as a common framework and guide to work together to produce increased understanding on the benefits of using alternative clinical combinations to affect strategic and cost-effective clinical workflows.

Generation of mammaglobin-A-specific CD4 T cells and identification of candidate CD4 epitopes for breast cancer vaccine strategies

BACKGROUND

Mammaglobin-A (MGB) is a breast cancer-associated antigen that is an attractive target for immune intervention. MGB has been shown to induce a specific CD8 T cell response in breast cancer patients, but little is known about a possible MGB-specific CD4 T cell response.

METHODS

Peripheral blood-derived CD4(+)CD25(-) T cells were stimulated in vitro with MGB-pulsed antigen-presenting cells (APC). The MGB and human leukocyte antigen (HLA) class II specificity of the CD4 T cell lines was confirmed by cytokine release following restimulation with autologous and allogenic APC pulsed with MGB from different sources. Candidate HLA class II-restricted epitopes were identified by computer algorithm and validated in cytokine release assays.

RESULTS

MGB-specific CD4 T cells were successfully generated in cultures from six of seven donors. Restimulation of MGB-specific CD4 T cells with MGB-pulsed APC induced significantly higher levels of interferon (IFN)-gamma release than APC pulsed with an irrelevant protein (P = 0.0004). Cultures from five of seven donors showed a pure Th1 type response as evidenced by the absence of interleukin (IL)-4. MGB-specific CD4 T cells recognized both recombinant and naturally processed MGB presented by APC. This recognition was HLA class II-restricted, as HLA-DR mismatched APC were not recognized. MGB-specific CD4 T cells from three of four donors recognized MGB-derived, HLA class II-restricted peptides pulsed onto APC.

CONCLUSIONS

We have successfully generated MGB-specific CD4 T cell cultures and identified candidate MGB HLA class II epitopes. These studies should facilitate study of the CD4 T cell response to MGB, and the development and monitoring of vaccine strategies targeting this unique antigen.

Nectin-4 is a new histological and serological tumor associated marker for breast cancer

Introduction

Breast cancer is a complex and heterogeneous disease at the molecular level. Evolution is difficult to predict according to classical histoclinical prognostic factors. Different studies highlight the importance of large-scale molecular expression analyses to improve taxonomy of breast cancer and prognostic classification. Identification of new molecular markers that refine this taxonomy and improve patient management is a priority in the field of breast cancer research.

Nectins are cell adhesion molecules involved in the regulation of epithelial physiology. We present here Nectin-4/PVRL4 as a new histological and serological tumor associated marker for breast carcinoma.

Methods

Expression of Nectin-4 protein was measured on a panel of 78 primary cells and cell lines from different origins and 57 breast tumors by FACS analysis and immunohistochemistry (IHC), respectively. mRNA expression was measured by quantitative PCR.

Serum Nectin-4 was detected by ELISA and compared with CEA and CA15.3 markers, on panels of 45 sera from healthy donors, 53 sera from patients with non-metastatic breast carcinoma (MBC) at diagnosis, and 182 sera from patients with MBC. Distribution of histological/serological molecular markers and histoclinical parameters were compared using the standard Chi-2 test.

Results

Nectin-4 was not detected in normal breast epithelium. By contrast, Nectin-4 was expressed in 61% of ductal breast carcinoma vs 6% in lobular type. Expression of Nectin-4 strongly correlated with the basal-like markers EGFR, P53, and P-cadherin, and negatively correlated with the luminal-like markers ER, PR and GATA3. All but one ER/PR-negative tumors expressed Nectin-4. The detection of Nectin-4 in serum improves the follow-up of patients with MBC: the association CEA/CA15.3/Nectin-4 allowed to monitor 74% of these patients compared to 67% with the association CEA/CA15.3. Serum Nectin-4 is a marker of disease progression, and levels correlate with the number of metastases (P = 0.038). Serum Nectin-4 is also a marker of therapeutic efficiency and correlates, in 90% of cases, with clinical evolution.

Conclusion

Nectin-4 is a new tumor-associated antigen for breast carcinoma. Nectin-4 is a new bio-marker whose use could help refine breast cancer taxonomy and improve patients' follow-up. Nectin-4 emerges as a potential target for breast cancer immunotherapy.

Mass spectrometry-based "omics" technologies in cancer diagnostics

Many "omics" techniques have been developed for one goal: biomarker discovery and early diagnosis of human cancers. A comprehensive review of mass spectrometry-based "omics" approaches performed on various biological samples for molecular diagnosis of human cancers is presented in this article. Furthermore, the existing and potential problems/solutions (both de facto experimental and bioinformatic challenges), and future prospects have been extensively discussed. Although the use of present omic methods as diagnostic tools are still in their infant stage and consequently not ready for immediate clinical use, it can be envisaged that the "omics"-based cancer diagnostics will gradually enter into the clinic in next 10 years as an important supplement to current clinical diagnostics.

Lipophilin B: A gene preferentially expressed in breast tissue and upregulated in breast cancer

Lipophilin B (LPB), which is also known as BU101, is a secretoglobin which exists in vivo as a complex with the mammary-specific protein, mammaglobin A (MGA). The aim of our study was to investigate the expression of LPB in a panel of breast and nonbreast tissues and compare its expression with that of MGA. Using RT-PCR, LPB mRNA was detected in 16/25 (64%) of normal breast specimens, 23/30 (77%) of fibroadenomas, 102/156 (65%) of primary breast cancers and in 8/36 (22%) nonbreast tissues. Levels of expression of LPB mRNA were significantly higher in breast cancers compared to both normal breast tissues (p = 0.02) and nonbreast tissue (p < 0.001). In the primary breast cancers, expression of LPB mRNA was positively correlated with the estrogen receptor (p = 0.045) but inversely related to both tumor grade (p < 0.001) and proliferation rates (p = 0.0345). Compared to MGA, expression of LPB was more sensitive but less specific for breast cancer. Using Western blotting, LPB migrated with an approximate molecular mass of 7-8 kDa, the expected molecular mass of free LPB. Immunohistochemical analysis of breast cancers showed that LPB expression was predominantly confined to the cytoplasm of tumor cells. We conclude that expression of LPB is preferentially but not exclusively restricted to breast tissue. Since LPB was expressed relatively specifically in breast tissue and was significantly upregulated in breast carcinomas, it is a promising candidate biomarker for breast cancer.

Molecular biomarkers for cancer detection in blood and bodily fluids

Cancer is a major and increasing public health problem worldwide. Traditionally, the diagnosis and staging of cancer, as well as the evaluation of response to therapy have been primarily based on morphology, with relatively few cancer biomarkers currently in use. Conventional biomarker studies have been focused on single genes or discrete pathways, but this approach has had limited success because of the complex and heterogeneous nature of many cancers. The completion of the human genome project and the development of new technologies have greatly facilitated the identification of biomarkers for assessment of cancer risk, early detection of primary cancers, monitoring cancer treatment, and detection of recurrence. This article reviews the various approaches used for development of such markers and describes markers of potential clinical interest in major types of cancer. Finally, we discuss the reasons why so few cancer biomarkers are currently available for clinical use.

A serum glycomics approach to breast cancer biomarkers

Because the glycosylation of proteins is known to change in tumor cells during the development of breast cancer, a glycomics approach is used here to find relevant biomarkers of breast cancer. These glycosylation changes are known to correlate with increasing tumor burden and poor prognosis. Current antibody-based immunochemical tests for cancer biomarkers of ovarian (CA125), breast (CA27.29 or CA15-3), pancreatic, gastric, colonic, and carcinoma (CA19-9) target highly glycosylated mucin proteins. However, these tests lack the specificity and sensitivity for use in early detection. This glycomics approach to find glycan biomarkers of breast cancer involves chemically cleaving oligosaccharides (glycans) from glycosylated proteins that are shed or secreted by breast cancer tumor cell lines. The resulting free glycan species are analyzed by MALDI-FT-ICR MS. Further structural analysis of the glycans can be performed in FTMS through the use of tandem mass spectrometry with infrared multiphoton dissociation. Glycan profiles were generated for each cell line and compared. These methods were then used to analyze sera obtained from a mouse model of breast cancer and a small number of serum samples obtained from human patients diagnosed with breast cancer or patients with no known history of breast cancer. In addition to the glycosylation changes detected in mice as mouse mammary tumors developed, glycosylation profiles were found to be sufficiently different to distinguish patients with cancer from those without. Although the small number of patient samples analyzed so far is inadequate to make any legitimate claims at this time, these promising but very preliminary results suggest that glycan profiles may contain distinct glycan biomarkers that may correspond to glycan "signatures of cancer."