Mammaglobin: a candidate diagnostic marker for breast cancer

A reduced proteomic signature in critically ill Covid-19 patients determined with plasma antibody micro-array and machine learning

BACKGROUND

COVID-19 is a complex, multi-system disease with varying severity and symptoms. Identifying changes in critically ill COVID-19 patients' proteomes enables a better understanding of markers associated with susceptibility, symptoms, and treatment. We performed plasma antibody microarray and machine learning analyses to identify novel proteins of COVID-19.

METHODS

A case-control study comparing the concentration of 2000 plasma proteins in age- and sex-matched COVID-19 inpatients, non-COVID-19 sepsis controls, and healthy control subjects. Machine learning was used to identify a unique proteome signature in COVID-19 patients. Protein expression was correlated with clinically relevant variables and analyzed for temporal changes over hospitalization days 1, 3, 7, and 10. Expert-curated protein expression information was analyzed with Natural language processing (NLP) to determine organ- and cell-specific expression.

RESULTS

Machine learning identified a 28-protein model that accurately differentiated COVID-19 patients from ICU non-COVID-19 patients (accuracy = 0.89, AUC = 1.00, F1 = 0.89) and healthy controls (accuracy = 0.89, AUC = 1.00, F1 = 0.88). An optimal nine-protein model (PF4V1, NUCB1, CrkL, SerpinD1, Fen1, GATA-4, ProSAAS, PARK7, and NET1) maintained high classification ability. Specific proteins correlated with hemoglobin, coagulation factors, hypertension, and high-flow nasal cannula intervention (P < 0.01). Time-course analysis of the 28 leading proteins demonstrated no significant temporal changes within the COVID-19 cohort. NLP analysis identified multi-system expression of the key proteins, with the digestive and nervous systems being the leading systems.

CONCLUSIONS

The plasma proteome of critically ill COVID-19 patients was distinguishable from that of non-COVID-19 sepsis controls and healthy control subjects. The leading 28 proteins and their subset of 9 proteins yielded accurate classification models and are expressed in multiple organ systems. The identified COVID-19 proteomic signature helps elucidate COVID-19 pathophysiology and may guide future COVID-19 treatment development.

Single-cell sequencing reveals the immune landscape of breast cancer patients with brain metastasis

BACKGROUND

Breast cancer has the highest incidence rate of cancer worldwide, and brain metastases (BrM) are among the most malignant cases. While some patients have benefited from immune checkpoint inhibitors (ICIs), the complex anatomical structure of the brain and the heterogeneity of metastatic tumors have made it difficult to characterize the tumor immune microenvironment (TME) of metastatic tumors.

METHODS

To address this, we used single-cell RNA sequencing (scRNA-seq) to analyze immune cells in the cerebrospinal fluid (CSF) of BrM patients with breast cancer, thereby providing a comprehensive view of the immune microenvironment landscape of BrM.

RESULTS

Based on canonical marker genes, we identified nine cell types, and further identified their subtypes through differential expression gene (DEG) analysis. We compared the changes in cells and functions in the immune microenvironment of patients with different prognoses. Our analysis revealed a series of genes that promote tumor immune function (CCR5, LYZ, IGKC, MS4A1, etc.) and inhibit tumor immune function (SCGB2A2, CD24, etc.).

CONCLUSIONS

The scRNA-seq in CSF provides a noninvasive method to describe the TME of breast cancer patients and guide immunotherapy.

The Enigma of Mammaglobin: Redefining the Biomarker Paradigm in Breast Carcinoma

The continuous evolution of cancer biology has led to the discovery of mammaglobin, a potential novel biomarker for breast carcinoma. This review aims to unravel the enigmatic aspects of mammaglobin and elucidate its potential role in redefining the paradigm of breast carcinoma biomarkers. We will thoroughly examine its expression in tumoral and peritumoral tissues and its circulating levels in the blood, thereby providing insights into its possible function in cancer progression and metastasis. Furthermore, the potential application of mammaglobin as a non-invasive diagnostic tool and a target for personalized treatment strategies will be discussed. Given the increasing incidence of breast carcinoma worldwide, the exploration of novel biomarkers such as mammaglobin is crucial in advancing our diagnostic capabilities and treatment modalities, ultimately contributing to improved patient outcomes.

Marker assessments in ER-positive breast cancers: old markers, new applications?

Evaluation of oestrogen receptor (ER) expression by immunostaining is essential in the pathological assessment of breast cancer. Its expression is intercorrelated with clinicopathological features, molecular typing, and treatment selection. The development of novel therapeutic agents related to ER status, the recent ASCO introduction of an ER-low positive category of breast cancers, and the ever-increasing plethora of diagnostic and theragnostic markers call for a timely update. In this article we aim to review the clinicopathological features of ER-positive breast cancers, with an emphasis on ER-low positive breast cancers, and a focus on updating the (i) assessment, reporting and interpretation of ER immunohistochemical (IHC) staining, (ii) correlations of ER status with other diagnostic and theragnostic markers, and (iii) implications for treatment selection and response. In the face of the developments in IHC and molecular techniques and targeted therapy, ER immunostaining is still expected to remain as the core component of prognostic and theragnostic assessment of breast cancers.

A single-cell analysis of breast cancer cell lines to study tumour heterogeneity and drug response

Cancer cells within a tumour have heterogeneous phenotypes and exhibit dynamic plasticity. How to evaluate such heterogeneity and its impact on outcome and drug response is still unclear. Here, we transcriptionally profile 35,276 individual cells from 32 breast cancer cell lines to yield a single cell atlas. We find high degree of heterogeneity in the expression of biomarkers. We then train a deconvolution algorithm on the atlas to determine cell line composition from bulk gene expression profiles of tumour biopsies, thus enabling cell line-based patient stratification. Finally, we link results from large-scale in vitro drug screening in cell lines to the single cell data to computationally predict drug responses starting from single-cell profiles. We find that transcriptional heterogeneity enables cells with differential drug sensitivity to co-exist in the same population. Our work provides a framework to determine tumour heterogeneity in terms of cell line composition and drug response.

Management of leptomeningeal metastasis in breast cancer

Leptomeningeal metastasis (LM), which occurs when malignant cells spread to the central nervous system, is becoming an increasingly common complication in patients with breast cancer. Diagnosis and treatment of LM is challenging. Moreover, prognosis of patients with LM is poor, with a median survival of 6 months after diagnosis. This review highlights the strengths and limitations of currently available diagnostic tools and therapies for LM. The current treatments for LM, including radiotherapy, systemic therapy, and intrathecal treatment, aim to maintain the quality of life of patients by correcting neurological deficits and arresting neurological degeneration. However, there is no standardized therapy for LM because of a lack of randomized trials on this condition.

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.

Modulation of Molecular Biomarker Expression in Response to Chemotherapy in Invasive Ductal Carcinoma

Breast cancer (BC) has varied morphological and biological features and is classified based on molecular and morphological examinations. Molecular classification of BC is based on biological gene-expression profiling. In this study, biomarker modulation was assessed during BC treatment in 30 previously untreated patients. Heterogeneity among patients was pathologically diagnosed and classified into luminal and basal-like immunohistochemical profiles based on estrogen, progesterone, and human epidermal growth factor receptor (ER/PR/HER2) status. Marker heterogeneity was compared with mRNA biomarker expression in patients with BC before and after therapy. Reverse transcription-polymerase chain reaction was performed for molecular characterization. Expression and modulation of biological markers, CK19, hMAM, CEA, MUC, Myc, Ki-67, HER2/neu, ErbB2, and ER, were assessed after treatment, where the expression of the biomarkers CK19, Ki-67, Myc, and CEA was noted to be significantly decreased. Marker expression modulation was determined according to different stages and pathological characteristics of patients; coexpression of three markers (CK19, Ki-67, and Myc) was specifically modulated after therapy. In the histopathologically classified basal-like group, two markers (CK19 and Ki-67) were downregulated and could be considered as diagnostic biomarkers. In conclusion, pathological characteristics and marker variation levels can be evaluated to decide a personalized treatment for patients.

In vitro selections of mammaglobin A and mammaglobin B aptamers for the recognition of circulating breast tumor cells

Mammaglobin B (MGB2) and mammaglobin A (MGB1) are proteins expressed in metastatic breast cancers. The early detection of circulating tumor cells (CTCs) in breast cancer patients is crucial to decrease mortality rate. Herein, novel aptamers were successfully selected and characterized against MGB2 and MGB1 proteins using a hybrid SELEX approach. The potential use of the selected aptamers in breast CTC detection was studied using spiked breast cancer cells in whole blood lysate. The results obtained from this study showed that the selected aptamers (MAMB1 and MAMA2) bind to their target breast cancer cell lines with high affinity (low nanomolar Kd values) and specificity. They also bind to their free recombinant target proteins and show minimal non-specific binding to normal and other cancer cell lines. Additionally, they were able to distinguish a low number of breast cancer cells spiked in whole blood lysate containing normal blood cells. The results obtained in this study indicate the great potential for the use of aptamers to detect MGB1 and MGB2 protein biomarkers, expressed on the surface of breast CTCs.

A multicentre validation of Metasin: a molecular assay for the intraoperative assessment of sentinel lymph nodes from breast cancer patients

AIMS

Treatment strategies for breast cancer continue to evolve. No uniformity exists in the UK for the management of node-positive breast cancer patients. Most centres continue to use conventional histopathology of sampled sentinel lymph nodes (SLNs), which requires delayed axillary clearance in up to 25% of patients. Some use touch imprint cytology or frozen section for intraoperative testing, although both have inherent sensitivity issues. An intraoperative molecular diagnostic approach helps to overcome some of these limitations. The aim of this study was to assess the clinical effectiveness of Metasin, a molecular method for the intraoperative evaluation of SLNs.

METHODS AND RESULTS

RNA from 3296 lymph nodes from 1836 patients undergoing SLN assessment was analysed with Metasin. Alternate slices of tissue were examined in parallel by histology. Cases deemed to be discordant were analysed by protein gel electrophoresis. There was concordance between Metasin and histology in 94.1% of cases, with a sensitivity of 92% [95% confidence interval (CI) 88-94%] and a specificity of 97% (95% CI 95-97%). Positive and negative predictive values were 88% and 98%, respectively. Over half of the discordant cases (4.4%) were ascribed to tissue allocation bias (TAB).

CONCLUSIONS

Clinical validation of the Metasin assay suggests that it is sufficiently sensitive and specific to make it fit for purpose in the intraoperative setting.

New look inside human breast ducts with Raman imaging. Raman candidates as diagnostic markers for breast cancer prognosis: Mammaglobin, palmitic acid and sphingomyelin

Looking inside the human body fascinated mankind for thousands of years. Current diagnostic and therapy methods are often limited by inadequate sensitivity, specificity and spatial resolution. Raman imaging may bring revolution in monitoring of disease and treatment. The main advantage of Raman imaging is that it gives spatial information about various chemical constituents in defined cellular organelles in contrast to conventional methods (liquid chromatography/mass spectrometry, NMR, HPLC) that rely on bulk or fractionated analyses of extracted components. We demonstrated how Raman imaging can drive the progress on breast cancer just unimaginable a few years ago. We looked inside human breast ducts answering fundamental questions about location and distribution of various biochemical components inside the lumen, epithelial cells of the duct and the stroma around the duct during cancer development. We have identified Raman candidates as diagnostic markers for breast cancer prognosis: carotenoids, mammaglobin, palmitic acid and sphingomyelin as key molecular targets in ductal breast cancer in situ, and propose the molecular mechanisms linking oncogenes with lipid programming.

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.

Trial watch: Naked and vectored DNA-based anticancer vaccines

One type of anticancer vaccine relies on the administration of DNA constructs encoding one or multiple tumor-associated antigens (TAAs). The ultimate objective of these preparations, which can be naked or vectored by non-pathogenic viruses, bacteria or yeast cells, is to drive the synthesis of TAAs in the context of an immunostimulatory milieu, resulting in the (re-)elicitation of a tumor-targeting immune response. In spite of encouraging preclinical results, the clinical efficacy of DNA-based vaccines employed as standalone immunotherapeutic interventions in cancer patients appears to be limited. Thus, efforts are currently being devoted to the development of combinatorial regimens that allow DNA-based anticancer vaccines to elicit clinically relevant immune responses. Here, we discuss recent advances in the preclinical and clinical development of this therapeutic paradigm.

Mammaglobin-A immunohistochemistry in primary central nervous system neoplasms and intracranial metastatic breast carcinoma

Metastases represent the most common type of intracranial neoplasm. In women, 30% of such tumors derive from breast carcinoma. In neurosurgical cases with ambiguous cellular morphology and/or limited biopsy material, immunohistochemistry (IHC) is often performed to distinguish metastases from primary central nervous system (CNS) neoplasms. IHC for mammaglobin-A (MGA), a protein expressed in a majority of breast carcinomas, is commonly applied in this setting, but its utility for distinguishing primary CNS neoplasms from metastatic breast carcinoma is unknown; the reactivity of MGA in primary and metastatic CNS neoplasms has never been described. Here, we describe the frequency and patterns of IHC reactivity for MGA in metastatic and primary CNS neoplasms from patients with well-documented histories of breast carcinoma. Following a published protocol previously applied to non-CNS neoplasms, MGA staining of moderate to strong intensity within 5% or more of a neoplasm was considered positive. On the basis of these criteria, 3 of 12 (25.0%) glioblastomas, 1 of 10 (10.0%) meningiomas, and 47 of 95 (49.5%) metastases were positive. Importantly, the cytoarchitectural staining characteristics among all 4 MGA-positive primary CNS neoplasms (cytoplasmic and nuclear) differed from those of the metastases (cytoplasmic and membranous). These findings suggest that MGA IHC staining intensity and distribution can distinguish metastases from primary CNS neoplasms (P=0.0086) in women with a history of breast carcinoma but also indicate that cytologic staining patterns must be interpreted for more accurate tumor classification.

Trial Watch: DNA vaccines for cancer therapy

During the past 2 decades, the possibility that preparations capable of eliciting tumor-specific immune responses would mediate robust therapeutic effects in cancer patients has received renovated interest. In this context, several approaches to vaccinate cancer patients against their own malignancies have been conceived, including the administration of DNA constructs coding for one or more tumor-associated antigens (TAAs). Such DNA-based vaccines conceptually differ from other types of gene therapy in that they are not devised to directly kill cancer cells or sensitize them to the cytotoxic activity of a drug, but rather to elicit a tumor-specific immune response. In spite of an intense wave of preclinical development, the introduction of this immunotherapeutic paradigm into the clinical practice is facing difficulties. Indeed, while most DNA-based anticancer vaccines are well tolerated by cancer patients, they often fail to generate therapeutically relevant clinical responses. In this Trial Watch, we discuss the latest advances on the use of DNA-based vaccines in cancer therapy, discussing the literature that has been produced around this topic during the last 13 months as well as clinical studies that have been launched in the same time frame to assess the actual therapeutic potential of this intervention.

Microarray analysis of port wine stains before and after pulsed dye laser treatment

BACKGROUND AND OBJECTIVES

Neither the pathogenesis of port wine stain (PWS) birthmarks nor tissue effects of pulsed dye laser (PDL) treatment of these lesions is fully understood. There are few published reports utilizing gene expression analysis in human PWS skin. We aim to compare gene expression in PWS before and after PDL, using DNA microarrays that represent most, if not all, human genes to obtain comprehensive molecular profiles of PWS lesions and PDL-associated tissue effects.

MATERIALS AND METHODS

Five human subjects had PDL treatment of their PWS. One week later, three biopsies were taken from each subject: normal skin (N); untreated PWS (PWS); PWS post-PDL (PWS + PDL). Samples included two lower extremity lesions, two facial lesions, and one facial nodule. High-quality total RNA isolated from skin biopsies was processed and applied to Affymetrix Human gene 1.0ST microarrays for gene expression analysis. We performed a 16 pair-wise comparison identifying either up- or down-regulated genes between N versus PWS and PWS versus PWS + PDL for four of the donor samples. The PWS nodule (nPWS) was analyzed separately.

RESULTS

There was significant variation in gene expression profiles between individuals. By doing pair-wise comparisons between samples taken from the same donor, we were able to identify genes that may participate in the formation of PWS lesions and PDL tissue effects. Genes associated with immune, epidermal, and lipid metabolism were up-regulated in PWS skin. The nPWS exhibited more profound differences in gene expression than the rest of the samples, with significant differential expression of genes associated with angiogenesis, tumorigenesis, and inflammation.

CONCLUSION

In summary, gene expression profiles from N, PWS, and PWS + PDL demonstrated significant variation within samples from the same donor and between donors. By doing pair-wise comparisons between samples taken from the same donor and comparing these results between donors, we were able to identify genes that may participate in formation of PWS and PDL effects. Our preliminary results indicate changes in gene expression of angiogenesis-related genes, suggesting that dysregulation of angiogenic signals and/or components may contribute to PWS pathology.

HLA Class II tetramers reveal tissue-specific regulatory T cells that suppress T-cell responses in breast carcinoma patients

Regulatory T cells (Tregs) play an important role in controlling antitumor T-cell responses and hence represent a considerable obstacle for cancer immunotherapy. The abundance of specific Treg populations in cancer patients has been poorly analyzed so far. Here, we demonstrate that in breast cancer patients, Tregs often control spontaneous effector memory T-cell responses against mammaglobin, a common breast tissue-associated antigen that is overexpressed by breast carcinoma. Using functional assays, we identified a HLA-DRB1*04:01- and HLA-DRB1*07:01-restricted epitope of mammaglobin (mam_34–48) that was frequently recognized by Tregs isolated from breast cancer patients. Using mam_34–48-labeled HLA Class II tetramers, we quantified mammaglobin-specific Tregs and CD4⁺ conventional T (Tcon) cells in breast carcinoma patients as well as in healthy individuals. Both mammaglobin-specific Tregs and Tcon cells were expanded in breast cancer patients, each constituting approximately 0.2% of their respective cell subpopulations. Conversely, mammaglobin-specific Tregs and CD4⁺ Tcon cells were rare in healthy individuals (0.07%). Thus, we provide here for the first time evidence supporting the expansion of breast tissue-specific Tregs and CD4⁺ Tcon cells in breast cancer patients. In addition, we substantiate the potential implications of breast tissue-specific Tregs in the suppression of antitumor immune responses in breast cancer patients. The HLA Class II tetramers used in this study may constitute a valuable tool to elucidate the role of antigen-specific Tregs in breast cancer immunity and to monitor breast cancer-specific CD4⁺ T cells.

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%).

GeneSearch™ BLN Assay could replace frozen section and touch imprint cytology for intra-operative assessment of breast sentinel lymph nodes

BACKGROUND

Breast cancer sentinel lymph node (SLN) biopsy has become a common procedure. The GeneSearch™ Breast Lymph Node Assay is a real-time reverse-transcriptase polymerase chain reaction assay for detecting nodal metastases larger than 0.2 mm. The trial is a prospective multi-center clinical trial conducted to validate the assay in China.

METHODS

Four hundred and seventy-nine consecutive prospective patients were enrolled from six centers. SLNs were sectioned along the short axis into multiple blocks. Odd blocks were tested by the assay intra-operatively, and even blocks were assessed by post-operative histology. Six 4- to 6-μm-thick sections were taken every 150 μm per block. In addition, intra-operative histological assessments were performed on the even blocks of 214 patients by frozen section (FS) and all blocks of 156 patients by touch imprint cytology (TIC).

RESULTS

A total of 1046 SLNs were excised. Overall performance of the assay compared to post-operative histology was accuracy of 91.4 %, sensitivity of 87.5 %, and specificity of 92.9 %. There were no significant differences in assay performance of each center. After a learning curve of about 10 cases, the assay could be performed in a median time of about 35 min. The sensitivity of the assay was similar to the FS (84.9 %, P = 0.885) and was significantly higher than the TIC (70.0 %, P = 0.007) while the specificity of all were comparable.

CONCLUSION

The GeneSearch™ Breast Lymph Node Assay is an accurate and rapid intra-operative assay for breast SLNs and it can replace FS and TIC for application.

Gross cystic disease fluid protein-15 and mammaglobin A expression determined by immunohistochemistry is of limited utility in triple-negative breast cancer

AIMS

  In addition to oestrogen and progesterone receptors, gross cystic disease fluid protein-15 (GCDFP-15) and mammaglobin A (MAM) are the most common markers used to identify breast origin by immunohistochemistry. GCDFP-15 expression has been reported in approximately 60% of breast carcinomas and MAM expression in approximately 80%. Data on their expression in triple-negative breast cancer (TNBC) are very limited. The aim of this study was to examine the expression of these markers in TNBC to determine their utility in pathological diagnosis.

METHODS AND RESULTS

  We studied the immunohistochemical (IHC) expression of GCDFP-15 and MAM in 63 primary and 118 metastatic TNBCs. GCDFP-15 staining was present in 14% of primary and 21% of metastatic TNBCs. MAM staining was present in 25% of primary and 41% of metastatic TNBCs. The frequency of expression of GCDFP-15 and/or MAM was 30% in primary and 43% in metastatic TNBCs, and many positive tumours had only focal staining.

CONCLUSIONS

  Staining for GCDFP-15 and/or MAM in triple-negative carcinomas helps to confirm breast origin, but most tumours in this subgroup of breast carcinomas lack expression of either marker.

Molecular markers in peripheral blood of Iranian women with breast cancer

A biomarker is a quantifiable laboratory measure of a disease specific biologically relevant molecule that can act as an indicator of a current or future disease state. The purpose of this study is to detect the expression of RNA biomarkers using Cytokeratin 19 (CK-19), Mammaglobin (MAM), Carcinoembryonic antigen (CEA), Mucin (MUC), C-Myc, erb-B2, a proliferation marker (Ki-67), Epidermal growth factor receptor (Her2/neu) and Estrogen receptor (ER) in Iranian women who were diagnosed with breast cancer. In this study, 90 samples; 60 cancer patients and 30 healthy controls were considered. 73.4 % patients were in stage I/II and 26.6 % were in stage III/IV. Patients were selected prior to the administration of any adjuvant systemic therapy. Total RNA extraction was obtained from peripheral blood of each patient and healthy control. Reverse transcription polymerase chain reaction (RT-PCR) method was used for detection of mRNA of the selected biomarkers of circulating breast cancer cells in blood. Molecular characterization is assessed as a method for early detection of breast cancer. For this purpose, eleven specific primers were selected and RT-PCR was used. The data of RT-PCR revealed that expression of MUC1, CK19, CEA, MAM, erbB-2, Ki67 and C-Myc biomarkers were significantly different between breast cancer patients and healthy controls. On the other hand, ERα, ERβ and Her2 markers were not significantly different between the two mentioned groups. Biomarkers detection of breast cancer patients could be assessed as a diagnostic factor and its potential for conveying as a prognostic factor require further studies, with a larger number of patients.

Breast cancer sentinel lymph node and axillary lymphadenectomy: new tools for new challenges

Axillary lymph node status at the time of diagnosis is the most important prognostic indicator for women with breast cancer, and may influence management decisions. However, at present its role is controversial, as some groups recommend avoiding axillary lymph node dissection (ALND) in cases with metastasis of any size in the sentinel lymph nodes. Molecular analysis allows full examination of the sentinel lymph nodes in a short time period, discriminatation between macrometastasis, micrometastasis and isolated tumor cells, and helps to predict the performance of ALND. ALND may be the treatment of choice in some patients, even in cases of low-volume metastasis, as chemotherapy does not control regional disease well. In addition, the collection of metastatic cells, as well as the local immune surveillance, is susceptible to further molecular studies that will offer prognostic and predictive information, which may have an impact on therapeutic decisions, so that individualized treatments can be adequately designed.

Update of the human secretoglobin (SCGB) gene superfamily and an example of 'evolutionary bloom' of androgen-binding protein genes within the mouse Scgb gene superfamily

The secretoglobins (SCGBs) comprise a family of small, secreted proteins found in animals exclusively of mammalian lineage. There are 11 human SCGB genes and five pseudogenes. Interestingly, mice have 68 Scgb genes, four of which are highly orthologous to human SCGB genes; the remainder represent an 'evolutionary bloom' and make up a large gene family represented by only six counterparts in humans. SCGBs are found in high concentrations in many mammalian secretions, including fluids of the lung, lacrimal gland, salivary gland, prostate and uterus. Whereas the biological activities of most individual SCGBs have not been fully characterised, what already has been discovered suggests that this family has an important role in the modulation of inflammation, tissue repair and tumorigenesis. In mice, the large Scgb1b and Scgb2b gene families encode the androgen-binding proteins, which have been shown to play a role in mate selection. Although much has been learned about SCGBs in recent years, clearly more research remains to be done to allow a better understanding of the roles of these proteins in human health and disease. Such information is predicted to reveal valuable novel drug targets for the treatment of inflammation, as well as designing biomarkers that might identify tissue damage or cancer.

Metaplastic and medullary mammary carcinomas do not express mammaglobin

Mammaglobin A (MG-A) is purportedly useful for detecting metastatic carcinomas suspected to be of breast origin and has been advocated as a useful marker of micrometastasis in sentinel lymph nodes and minimal residual tumor in bone marrow. Little is known about its expression frequency in histologic subtypes of breast cancer. Excisional biopsy specimens from 1,079 untreated invasive mammary carcinomas were evaluated for immunohistochemical expression of MG-A. In addition to estrogen (ER) and progesterone receptors (PR) and HER2, staining for p63 and HLA-DR was used to further characterize histologic subtypes. Of the carcinomas, 36 were classified as metaplastic (based on morphologic features, ER-/PR-/HER2-, p63+), 38 as medullary (ER-/PR-/HER2-, HLA-DR+), and 1,005 as ductal, no special type (NST). All metaplastic and medullary carcinomas were negative for MG-A. Of 1,005 ductal carcinomas, NST, 492 (49.0%) were MG-A+, 62.0% with a reaction in fewer than 25% of the cells. MG-A immunohistochemical studies failed to detect all medullary and metaplastic cancers and more than 50% of ductal carcinomas, NST. In two thirds of MG-A+ ductal carcinomas, the reaction was only focal and usually in a minority of cells. These findings suggest that MG-A has limited value in identifying the mammary origin of carcinomas, particularly in small biopsy specimens used to detect metastasis or minimal residual disease.

Analysis of EpCAM positive cells isolated from sentinel lymph nodes of breast cancer patients identifies subpopulations of cells with distinct transcription profiles

Introduction

The presence of tumor cells in the axillary lymph nodes is the most important prognostic factor in early stage breast cancer. However, the optimal method for sentinel lymph node (SLN) examination is still sought and currently many different protocols are employed. To examine two approaches for tumor cell detection we performed, in sequence, immunomagnetic enrichment and RT-PCR analysis on SLN samples from early stage breast cancer patients. This allowed us to compare findings based on the expression of cell surface proteins with those based on detection of intracellular transcripts.

Methods

Enrichment of EpCAM and Mucin 1 expressing cells from fresh SLN samples was achieved using magnetic beads coated with the appropriate antibodies. All resulting cell fractions were analyzed by RT-PCR using four chosen breast epithelial markers (hMAM, AGR2, SBEM, TFF1). Gene expression was further analyzed using RT-PCR arrays and markers for epithelial to mesenchymal transition (EMT).

Results

Both EpCAM and Mucin 1 enriched for the epithelial-marker expressing cells. However, EpCAM-IMS identified epithelial cells in 71 SLNs, whereas only 35 samples were positive with RT-PCR targeting breast epithelial transcripts. Further analysis of EpCAM positive but RT-PCR negative cell fractions showed that they had increased expression of MMPs, repressors of E-cadherin, SPARC and vimentin, all transcripts associated with the process of epithelial to mesenchymal transition.

Conclusions

The EpCAM IMS-assay detected tumor cells with epithelial and mesenchymal-like characteristics, thus proving to be a more robust marker than pure epithelial derived biomarkers. This finding has clinical implications, as most methods for SLN analysis today rely on the detection of epithelial transcripts or proteins.

A mammaglobin-A targeting agent for noninvasive detection of breast cancer metastasis in lymph nodes

Pathologic axillary lymph node (ALN) status is an important prognostic factor for staging breast cancer. Currently, status is determined by histopathology following surgical excision of sentinel lymph node(s), which is an invasive, time consuming, and costly procedure with potential morbidity to the patient. Here, we describe an imaging platform for noninvasive assessment of ALN status, eliminating the need for surgical examination of patients to rule out nodal involvement. A targeted imaging probe (MamAb-680) was developed by conjugation of a mammaglobin-A-specific monoclonal antibody to a near-infrared fluorescent dye. Using DNA and tissue microarray, mammaglobin-A was validated as a cell-surface target that is expressed in ALN-positive patient samples but is not expressed in normal lymph nodes. In vivo selectivity was determined by i.v. injection of MamAb-680 into mice with mammaglobin-A-positive and -negative mammary fat pad (MFP) tumors; and by peritumoral MFP injection of the targeted imaging probe in mice with spontaneous ALN metastases. Fluorescence imaging showed that probe was only retained in positive tumors and metastases. As few as 1,000 cells that endogenously express mammaglobin-A were detected in ALN, indicating high sensitivity of this method. Translation of this approach offers considerable potential as a noninvasive clinical strategy to stage breast cancer.

Hexapeptide libraries for enhanced protein PTM identification and relative abundance profiling in whole human saliva

Dynamic range compression (DRC) by hexapeptide libraries increases MS/MS-based identification of lower-abundance proteins in complex mixtures. However, two unanswered questions impede fully realizing DRC's potential in shotgun proteomics. First, does DRC enhance identification of post-translationally modified proteins? Second, can DRC be incorporated into a workflow enabling relative protein abundance profiling? We sought to answer both questions analyzing human whole saliva. Addressing question one, we coupled DRC with covalent glycopeptide enrichment and MS/MS. With DRC we identified ∼2 times more N-linked glycoproteins and their glycosylation sites than without DRC, dramatically increasing the known salivary glycoprotein catalog. Addressing question two, we compared differentially stable isotope-labeled saliva samples pooled from healthy and metastatic breast cancer women using a multidimensional peptide fractionation-based workflow, analyzing in parallel one sample portion with DRC and one portion without. Our workflow categorizes proteins with higher absolute abundance, whose relative abundance ratios are altered by DRC, from proteins of lower absolute abundance detected only after DRC. Within each of these salivary protein categories, we identified novel abundance changes putatively associated with breast cancer, demonstrating feasibility and benefits of DRC for relative abundance profiling. Collectively, our results bring us closer to realizing the full potential of DRC for proteomic studies.

Gene expression profiling guiding diagnosis and therapy of rare mammary-like anogenital gland carcinomas

Cancers derived from anogenital mammary-like glands are rare, and their identification and selection of treatment for dissemination may be difficult. We encountered two such tumors, which both presented as occult primaries with nodal and hematogenous metastases. They were studied by immunohistochemistry, HER2 receptor assay, and gene expression profiling. Both tumors had some microscopical and immunohistochemical features in common with breast cancer, but lacked estrogen and progesterone receptors. Taxane-platinum-based systemic chemotherapy did not stop progression in a male patient, in whom a developing inguinal skin lesion was the likely primary tumor. The same regimen gave partial remission in a later, female, patient. After the mammary-like, HER2 positive nature of her tumor was confirmed by gene expression profiling using CupPrint and TargetPrint assays, treatment with vinorelbine-trastuzumab induced complete remission that is maintained by trastuzumab alone for almost 4 years after initial diagnosis. Molecular and immunohistochemical characterization of these rare tumors may identify them and sometimes guide systemic chemotherapy away from a non-specific and "broad spectrum" regimen toward a targeted therapy, resulting in greater effectiveness with less side effects.

DETECTION OF DISSEMINATED TUMOR CELLS IN PERIPHERAL BLOOD

Metastases are the major cause of cancer-related deaths in patients with solid epithelial malignancies, such as breast, colorectal and prostate carcinomas. Hematogenous spreading of tumor cells from a primary tumor can be considered as a crucial step in the metastasis cascade leading eventually to the formation of clinically manifest metastases. Consequently, as shown in recent studies, the detection of disseminated tumor cells in peripheral blood might be of clinical relevance with respect to individual patient prognosis and staging or monitoring of therapy. However, the rarity of disseminated tumor cells in peripheral blood renders the application of sensitive techniques mandatory for their detection. The emergence of highly sophisticated reverse transciptase-polymerase chain reaction (RT-PCR) assays, combining a preanalytical enrichment step with the assessment of multiple molecular tumor markers expressed in disseminated tumor cells, provides a powerful tool in detecting disseminated tumor cells with high sensitivity and specificity. This review will discuss currently used tumor markers as well as experimental means to enhance the sensitivity and specificity of RT-PCR assays to detect disseminated tumor cells in the peripheral blood of patients with breast, colorectal, and prostate cancers, and their clinical relevance assessed in recent studies.

Application of immunohistochemistry to breast lesions

CONTEXT

Immunohistochemistry has an expanding role in mammary pathology that has been facilitated by a growing list of available antibodies and a better understanding of biology.

OBJECTIVE

To explore the key role of immunohistochemistry in guiding adjuvant therapy decisions and sentinel node staging in breast cancer, as well as the role of immunohistochemistry as an aid to distinguishing usual ductal hyperplasia from atypical ductal hyperplasia/low-grade carcinoma in situ; subtyping a carcinoma as ductal or lobular, basal or luminal; ruling out microinvasion in extensive intraductal carcinoma; distinguishing invasive carcinoma from mimics; and establishing that a metastatic carcinoma of unknown primary site has originated in the breast.

DATA SOURCES

Current literature is reviewed, including clinical and pathologic journals.

CONCLUSIONS

As new, targeted treatments for breast cancer are developed, pathologists can expect additional immunohistochemistry applications in the future.

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.

Sentinel node staging for breast cancer: intraoperative molecular pathology overcomes conventional histologic sampling errors

BACKGROUND

When sentinel node dissection reveals breast cancer metastasis, completion axillary lymph node dissection is ideally performed during the same operation. Intraoperative histologic techniques have low and variable sensitivity. A new intraoperative molecular assay (GeneSearch BLN Assay; Veridex, LLC, Warren, NJ) was evaluated to determine its efficiency in identifying significant sentinel lymph node metastases (>.2 mm).

METHODS

Positive or negative BLN Assay results generated from fresh 2-mm node slabs were compared with results from conventional histologic evaluation of adjacent fixed tissue slabs.

RESULTS

In a prospective study of 416 patients at 11 clinical sites, the assay detected 98% of metastases >2 mm and 88% of metastasis greater >.2 mm, results superior to frozen section. Micrometastases were less frequently detected (57%) and assay positive results in nodes found negative by histology were rare (4%).

CONCLUSIONS

The BLN Assay is properly calibrated for use as a stand alone intraoperative molecular test.

Specific isolation of disseminated cancer cells: a new method permitting sensitive detection of target molecules of diagnostic and therapeutic value

Molecular studies of rare cells, such as circulating cancer cells, require efficient pre-enrichment steps to obtain a pure population of target cells for further characterization. We have developed a two-step approach, starting with immunomagnetic enrichment, followed by specific isolation of individual, easily identifiable bead-rosetted target cells using a new semi-automated CellPick system. With this procedure, 1-50 live target cells can now be isolated. As a model system, we spiked a small number of tumor cells into millions of normal mononuclear cells (MNCs). Efficient isolation of pure target cells was obtained by use of the CellPick system, and the nature of isolated, bead-rosetted cells was verified by use of FISH. Single breast cancer cells were picked directly into an RNA preserving lysis buffer, reverse transcribed, and PCR amplified with two cDNA specific primer sets. With the isolated cells we consistently obtained both ubiquitously expressed and tumor cell specific PCR products. We also performed a successful mutation analysis of single cells using PCR and cycling temperature capillary electrophoresis (CTCE). This may have significant clinical implications in cancer and in other diseases, e.g. in characterizing micrometastatic cancer cells in blood and lymph nodes to help identifying patients who most likely will respond to therapies like tyrosine kinase inhibitors and compounds targeting specific mutations. By use of the CellPick system it is possible to specifically isolate bead-rosetted or otherwise labelled target cells from a heterogeneous cell population for further molecular characterization.

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.