Potential Breast Cancer Marker Research Articles

Characterization of SUSD3 as a novel prognostic biomarker and therapeutic target for breast cancer.

Breast cancer (BC) remains a significant global health challenge, contributing substantially to cancer-related deaths worldwide. Its prevalence and associated death rates remain alarmingly high, highlighting the persistent public health burden. The objective of this study was to systematically examine the involvement of SUSD3 (Sushi Domain-Containing 3) in BC, highlighting its crucial role in the pathogenesis and progression of this disease. BC-related gene microarray data, along with corresponding clinicopathological information, were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Leveraging TIMER and HPA databases, we conducted comparative analyses to evaluate SUSD3 expression in BC. We then analyzed the association between SUSD3 and clinical traits, as well as the prognostic value of SUSD3. SUSD3-related differential expression genes (DEGs) were sent for analysis utilizing GO, KEGG, and GSEA. We utilized SUSD3 mRNA expression to assess immune cells' scores in BC tissues calculated by single-sample enrichment analyses based on "CIBERSORT" R package. Drug sensitivity analysis was used to screen potential drugs sensitive to SUSD3. R software was used for statistical analyses and graphical representation of the data. Our findings confirmed a significant upregulation of SUSD3 expression in BC, which correlated with a favorable prognosis. Clinical correlation analysis further emphasized the strong association between SUSD3 expression and key clinical parameters like estrogen receptor (ER) status, progesterone receptor (PR) status, stage, and T classification in breast cancer. Univariate and multivariate Cox regression analyses showed that SUSD3 could be used as an independent prognostic factor for BC. Differentially expressed genes (DEGs) co-expressed with SUSD3 were significantly associated with various biological processes, such as the cell cycle, DNA replication, p53 signaling pathway, cancer-related pathways, and Wnt signaling pathway, as indicated by gene set enrichment analysis (GSEA). Furthermore, our analysis demonstrated that SUSD3 generally exhibited negative associations with immune modulators. Drug sensitivity analysis revealed positive correlations between SUSD3 and the efficacy of Fulvestrant, Raloxifene, and Fluphenazine. The research emphasizes the significance of SUSD3 as a potential marker for BC, providing insights into the underlying molecular mechanisms implicated in tumorigenesis. SUSD3 holds promise in helping the classification of breast cancer pathological groups, predicting prognosis, and facilitating targeted therapy.

DNAJB4 identified as a potential breast cancer marker: evidence from bioinformatics analysis and basic experiments

Breast cancer (BC) is the leading cause of tumor-related death in women worldwide, but its pathogenesis is not clear. The efficient screening of new therapeutic targets for BC through bioinformatics and biological experimental techniques has become a hot topic in BC research. The bioinformatics method was used to analyze the gene chips and obtain the hub genes, playing an important role in the development of BC. The biological processes (BP) involved in the hub genes were analyzed by Bingo, and the impact of each hub gene on disease-free survival (DFS) and overall survival (OS) in BC patients was evaluated in the Kaplan-Meier Plotter database. The expression of DNAJB4, the hub gene with the greatest degree and having an effect on the prognosis of BC patients, was detected in BC cell lines and clinicopathological specimens. And DNAJB4 was selected for further biological experiments and clinical prognosis verification. Ten hub genes including DNAJB4, the greatest degree genes, were found by bioinformatics analysis of BC gene chips. DNAJB4 expressions in both BC cell lines and clinicopathological specimens were detected and the results showed that DNAJB4 was significantly down-regulated in BC cell lines and tissues. After interfering with the expression of DNAJB4, it was found that the invasion and migration ability of MDA-MB-231 cell line was significantly enhanced in vitro. The clinical survival data of BC patients showed that patients with high DNAJB4 expression had longer DFS. DNAJB4 may be a tumor suppressor gene in BC as it could regulate invasion and migration of BC cells and its expression level is related to the prognosis of BC patients. Nevertheless, further researches are still necessary to verify its role in BC so as to provide evidences for clinical guidance regarding diagnosis and treatment.

P-CREB-1 at Ser 133 is a potential marker for breast cancer.

Dysregulation of numerous oncogenes and their downstream signaling pathways, among others in the signaling transduction molecule p-CREB-1 (p-cAMP responsive element binding protein-1), is an essential feature of different types of cancer. To investigate whether p-CREB-1 is also pivotal in tumorigenesis and metastogenesis of breast cancer, we conducted a prospective study with long-term follow-up on 96 patients with breast cancer. Pathway array and tissue microarray (TMA) were used to detect the differential expression of CREB (cAMP-responsive element binding protein) and p-CREB-1 in breast cancer cells, breast cancer stem cells (BCSCs), human breast cancer tissues (BCTs), and adjacent normal tissues (ANTs). The associations between p-CREB-1 expression, clinicopathological variables, and survival rates of the patients were analyzed and calculated. Our results revealed that p-CREB-1 and CREB expression in cancerous cell lines and tissues were significantly upregulated compared with non-cancerous cell lines and tissues. Most statistically significant overexpression was detected in BCSCs (p<0.01). In TMA and immunohistochemical analyses, BCTs exhibited significantly higher expression of p-CREB-1 and CREB than ANTs (p<0.001). Clinicopathological variable and survival analysis revealed a correlation between high expression (++/+++) of p-CREB-1 and the presence of axillary lymph node metastasis (p<0.05) and poorer disease-free and overall survival. p-CREB-1 is a potential predictive and prognostic biomarker and a promising therapeutic target in breast cancer.

Comparative analysis of intact glycopeptides from mannose receptor among different breast cancer subtypes using mass spectrometry

Breast cancer is a highly heterogeneous disease, encompassing a number of biologically distinct entities with specific pathologic features and biological behaviors. In the preliminary experiments, we identified several glycosylation sites of mannose receptors in different breast cancer subtypes and showed that the mannose receptors could be a potential marker for breast cancer. However, the glycan composition on each site is still unknown because the glycan was removed by PNGase F in previous work. Analysis of intact glycopeptides can provide the information of both the glycan composition and the glycosylation site, which can further help to reveal the difference of glycosylation in the four subtypes of breast cancer. In this work, we analyzed the intact glycopeptides of the mannose receptors in serum from breast cancer patients using isobaric tags for relative and absolute quantitation (iTRAQ) and LC-MS/MS. In total, 7 glycosylation sites and 12 glycan types corresponding to 26 intact glycopeptides were characterized from the four subtypes of breast cancer. Among them, 11 glycopeptides can be used to differentiate the subtypes of breast cancer, which further supported the previous conclusion that mannose receptor can be used as a potential marker for the identification of breast cancer subtypes.

English

The multifunctional transmembrane mannose-6-phosphate/insulin-like growth factor-2 receptor (M6P/IGF2-R) has been proposed as a putative prognostic marker in breast cancer. Loss of heterozygosity (LOH) with mutations in the remaining allele have been described at the gene level. We previously reported significant decrease of M6P/IGF2-R at the protein level in cancer cells than normal peritumoral ducts of breast tumors which may indicate an increased release of the receptor from the cell membrane to the blood. To assess that hypothesis we measured in this study M6P/IGF2-R levels in serum of women with breast cancer by competitive enzyme-linked immunosorbent assay (ELISA) that allows a detectable sensitivity of 300 ng/mL. The results were obtained referring to a standard curve consisting in varying concentrations of human purified M6P/IGF2-R. Women sera consisted of cancer-free sera (n=39) or serum from women with breast cancer (n=39) were preincubated with anti-M6P/IGF2-R immunoglobulin Y (IgY) antibodies. High levels of M6P/IGF2-R (p<0.01) were found in serum from women with breast cancer in comparison with cancer-free serum. Overall the results support the hypothesis of increased release of the receptor from cancer cells to the blood and add one more argument for M6P/IGF2-R studying as a potential breast cancer marker. Key words: Mannose-6-Phosphate/Insulin-like Growth Factor-2 Receptor (M6P/IGF2-R), loss of heterozygosity (LOH), suppressor gene, breast cancer, competitive enzyme-linked immunosorbent assay (ELISA), IgY, biological marker.

Abstract 4927: Silencing of the RAD50 gene contributes to enhancing the sensitivity of the triple-negative breast cancer cells to carboplatin

Abstract Triple-negative (TN) breast cancer (BC) is the most aggressive molecular subtype of BC that affected over 250 thousand females worldwide just in 2018. Patients with TNBC have exhibited a higher probability of cancer relapses and poor prognosis of disease outcome which are due to the absence of established and reliable targets for therapy of this subtype of tumors. Only 10% of TN breast tumors have BRCA1/2 mutations associated with high sensitivity of cancer cells to the chemotherapy with platinum salts drugs (e.g., cisplatin, carboplatin (Cb), etc.) and PARP-inhibitors. Recent studies indicated that administration of Cb in neoadjuvant chemotherapy of TNBC increase pCR (pathologic complete response) of patients received Cb in comparison with a control group. Also, Phase II and III of clinical trials have shown that TNBC patients respond differently to adjuvant chemotherapy with Cb. Therefore further studies are required to define subgroups of TNBC patients, which might benefit from carboplatin therapy. In our previous studies, the RAD50 gene involved in radiation-induced DNA double-strand break repair was identified as a tumor-associated antigen and potential BC marker. We have shown that low expression of RAD50 gene is associated with better TNBC prognosis. The current study was aimed to evaluate RAD50 as a predictive marker of TNBC cells sensitivity to Cb. The RAD50 gene was silenced in triple negative breast cancer cell lines with wild-type BRCA genes namely MDA-MB-231, MDA-MB-436, and MDA-MB-453 by RNA interference. Then the changes of the cytotoxic sensitivity of these cells to Cb treatment in comparison to the control cells with original RAD50 expression were investigated by using a cell viability assay. Obtained data were analyzed by the Wilcoxon signed-rank test. The statistical analysis was performed using GraphPad Prism 7 software. Results of this study demonstrated that the knockdown of RAD50 gene expression in human TNBC cells could significantly increase their susceptibility to treatment with Cb (MDA-MB-231: IC50 - 20,65uM (silenced RAD50) and 24,93uM (control), p-value = 0,0098; MDA-MB-436: IC50 - 7,497uM (silenced RAD50) and 10,39uM (control), p-value = 0,0137; MDA-MB-453: IC50 - 7,336uM (silenced RAD50) and 8,711uM (control), p-value = 0,002). These results strongly indicate that silencing of the RAD50 expression contributes to the sensitization of TNBC cells to treatment with platinum-based drug Cb. Therefore RAD50 could be considered as important TNBC predictive biomarker. Further validation of RAD50 by using the tumors of TNBC patients and animal xenograft models could prove to be essential to use this marker for improving the therapy regimens of TNBC tumors without BRCA1/2 mutations. This work is performed according to the Russian Government Program of Competitive Growth of Kazan Federal University. Citation Format: Kristina V. Havrysh, Mikhail V. Bogdanov, Ramziya G. Kiyamova. Silencing of the RAD50 gene contributes to enhancing the sensitivity of the triple-negative breast cancer cells to carboplatin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4927.

Salivary VEGF - A Potential Breast Cancer Marker

Aims: To identify and estimate salivary VEGF of breast cancer patients using non invasive method. Methods: ELISA, Zymography, Immunoblot. Results: We observed that saliva of breast cancer patients express appreciably high VEGF compare to non breast cancer saliva samples. Conclusion: The findings indicate salivary VEGF as a potential breast cancer marker using non invasive method.

Galectin 1 overexpression in breast cancer tissues: Relation to serum matrix metalloproteinase 2 and 9 activity

ContextElevated expression of galectins correlates with neoplastic progression in certain malignancies. Matrix Metalloproteinases (MMPs) have been implicated in metastatic and angiogenic processes. Gal-1 promoted tumor invasion in oral cancer cell lines in part by augmenting MMP-2 and MMP-9 expression and enzymatic activities. ObjectiveOur aim was to assess the expression of Galectin-1 mRNA and correlate its expression with the clinico-pathological parameters and with potent serum (MMP 2, 9) activity in breast cancer. Materials and methodsSemi quantitative RT PCR analysis was done on all breast tissue samples (malignant and benign). Gelatin zymography was performed in order to detect both latent and activated forms of serum MMP-2 and 9 in the same patients. ResultsThere was a significant relation between Galectin-1 expression and the histological grade, stage of the tumor, presence of lymph node metastasis and potent MMP-2 and MMP-9 activity. ConclusionGalectin-1 could be a promising potential marker for breast cancer.

Identification of potential breast cancer markers in nipple discharge by protein profile analysis using two-dimensional nano-liquid chromatography/nanoelectrospray ionization-mass spectrometry.

This research aimed to establish a diagnostic technique for breast cancer using nipple discharge (ND), with the objective of preventive diagnosis. ND has been proposed as a source of secreted proteomes that reflect early pathological changes in the ductal-lobular epithelial microenvironment, and could thus provide breast-specific cancer biomarkers that could be accessed noninvasively as a new clinical diagnostic technique. Minute amounts of ND from patients with and without breast cancer (n = 19 and 12, respectively) were collected at the hospital and kept frozen until just before use. They were analyzed using high-pH RP peptide fractionations/low-pH RP 2D nano-LC/ESI-MS/MS. Biomarker candidates were also investigated using Western blot analysis and sandwich ELISA on ND and/or sera. We found distinct tendencies in protein expression and three candidate breast cancer biomarkers (carbonic anhydrase 2, catalase, and peroxiredoxin-2) whose levels differed significantly between ND specimens from patients with and without breast cancer. These tendencies in protein expression and markers provide new ways to identify breast cancer patients. Therefore, RP/RP 2D LC/MS/MS analyses of ND and the above three markers are supported as a new breast cancer diagnostic technique.

The label free picomolar detection of insulin in blood serum

Insulin, a polypeptide hormone secreted by pancreatic cells, is a key regulator in glucose homeostasis. Its deficiency leads to insulin-dependent (type I) diabetes whereas resistance to insulin is common in type II diabetes, obesity and a range of endocrine disorders. Its determination is of considerable value, particularly in the clinical diagnosis of diabetes mellitus and the doping control of athletes. It has, additionally, been noted as a potential breast cancer marker (serum insulin levels being found to be raised in comparison to control patients). Electrochemical assays are potentially very cheap, highly sensitive, and very readily transposed to a point of care. Though there exist numerous examples of label free impedimetric or capacitative assaying of biomolecules, these are rarely demonstrated to be effective in complex biological mixtures or to be applicable to low molecular weight targets (since they operate through the interfacial displacement of water/ions and/or the steric blocking of a redox probe). We report herein an ultrasensitive electrochemical and label-free biosensor for insulin in blood serum with a clinically relevant linear range and detection limit of 1.2pM. The transducing surfaces, based on readily prepared, antibody modified, polyethylene glycol monolayer modified polycrystalline gold surfaces, respond in a highly specific and re-useable manner to the target in up to 50% blood serum.

Surface plasmon resonance imaging in arrays coupled with mass spectrometry (SUPRA–MS): proof of concept of on-chip characterization of a potential breast cancer marker in human plasma

Protein biomarker discovery and validation are crucial for diagnosis, prognosis, and theranostics of human pathologies; "omics" approaches bring new insights in this field. In particular, the combination of immuno-sensors in array format with mass spectrometry efficiently extends the classical immunoassay format and includes molecular characterization. Here, we coupled surface plasmon resonance imaging (SPRi) with MALDI-TOF mass spectrometry in a hyphenated technique which enables multiplexed quantification of binding by SPRi and molecular characterization of interacting partners by subsequent MS analysis. This adds specificity, because MS enables differentiation of molecules that are difficult to distinguish by use of antibodies, for example truncation variants or protein isoforms. Proof of concept was established for detection, identification, and characterization of a potential breast cancer marker, the LAG3 protein, at ~1μgmL(-1), added to human plasma. The analytical performance of this new method, dubbed "SUPRA-MS", was established, particularly its specificity (S/N > 10) and reliability (100% LAG3 identification with high significant mascot score >87.9). The adjusted format for rapid, collective, and automated on-chip MALDI-MS analysis is robust at the femtomole level and has numerous potential applications in proteomics.

Canaux cationiques TRP dans le cancer du sein : expression, rôle et corrélation avec des paramètres cliniques

Breast cancer (BC) has the highest incidence rate in women in industrialized countries. Statistically, it is estimated that one out of 10 women will develop BC during her life. Evidence is accumulating for the role of ion channels in the development of cancer. Most studied ion channels in BC are K+ channels, which are involved in cell proliferation, cell cycle progression and cell migration, and Na+ channels, which correlate with invasiveness. Emerging studies demonstrated the role of Ca2+ signaling in cancer cell proliferation, survival and migration. Recent findings demonstrated that the expression and/or activity of the transient receptor potential (TRP) channels are altered in several cancers. Among the TRP families, TRPC (canonical or classical), TRPM (melastatin) and TRPV (vanilloid) are related to malignant growth and cancer progression. Although these channels are frequently and abundantly expressed in many tumors, their specific expression, activity and roles in BC are still poorly understood. The expression of TRP channels has also been proposed as a tool for diagnosis, prognosis and/or therapeutic issues of several diseases. In cancer, TRPV6 and TRPM8 have been proposed as tumor progression markers of prostate cancer outcome and TRPC6 as a novel therapeutic target for esophageal carcinoma. Interestingly high levels of TRPC3 expression correlate with a favorable prognosis in patients with lung adenocarcinoma. Our team has recently reported the expression and role of TRPC1, TRPC6, TRPM7, TRPM8 and TRPV6 in BC cell lines and primary cultures. We have also investigated TRP expression and their clinical significance in human breast adenocarcinoma and we suggest that TRP channels are new potential BC markers. Indeed TRPC1 and TRPM8 may be considered as good prognosis markers of well-differentiated tumors, TRPM7 as a proliferative marker of poorly differentiated tumors and TRPV6 as a prognosis marker of aggressive cancers. In this review, we summarize the data reported to date regarding the changes in TRP expression associated with BC. We also discuss the importance of TRP channels in BC cells proliferation and migration and their interest as new BC markers.

Automated Cancer Marker Characterization in Human Plasma Using SUrface PLASMON Resonance in Array combined with Mass Spectrometry (SUPRA-MS)

The combination of Surface Plasmon Resonance technology with Mass Spectrometry becomes a key method for the characterization of targeted proteins in the fields of diagnosis and functional proteomics. We demonstrated in this work the ability of our SPRi-chip to capture targeted protein in biological fluids and in situ analyze by MS and MS/MS modes through automated procedure to go beyond classical immunoassays. Here, we established a proof of concept of SUPRA-MS for the detection, the identification and the characterization of a potential breast cancer marker.

SNORD-host RNA Zfas1 is a regulator of mammary development and a potential marker for breast cancer

Long noncoding RNAs (lncRNAs) are increasingly recognized to play major regulatory roles in development and disease. To identify novel regulators in breast biology, we identified differentially regulated lncRNAs during mouse mammary development. Among the highest and most differentially expressed was a transcript (Zfas1) antisense to the 5' end of the protein-coding gene Znfx1. In vivo, Zfas1 RNA is localized within the ducts and alveoli of the mammary gland. Zfas1 intronically hosts three previously undescribed C/D box snoRNAs (SNORDs): Snord12, Snord12b, and Snord12c. In contrast to the general assumption that noncoding SNORD-host transcripts function only as vehicles to generate snoRNAs, knockdown of Zfas1 in a mammary epithelial cell line resulted in increased cellular proliferation and differentiation, while not substantially altering the levels of the SNORDs. In support of an independent function, we also found that Zfas1 is extremely stable, with a half-life >16 h. Expression analysis of the SNORDs revealed these were expressed at different levels, likely a result of distinct structures conferring differential stability. While there is relatively low primary sequence conservation between Zfas1 and its syntenic human ortholog ZFAS1, their predicted secondary structures have similar features. Like Zfas1, ZFAS1 is highly expressed in the mammary gland and is down-regulated in breast tumors compared to normal tissue. We propose a functional role for Zfas1/ ZFAS1 in the regulation of alveolar development and epithelial cell differentiation in the mammary gland, which, together with its dysregulation in human breast cancer, suggests ZFAS1 as a putative tumor suppressor gene.

Mitochondrial proteomics analysis of tumorigenic and metastatic breast cancer markers

Mitochondria are key organelles in mammary cells responsible for several cellular functions including growth, division, and energy metabolism. In this study, mitochondrial proteins were enriched for proteomics analysis with the state-of-the-art two-dimensional differential gel electrophoresis and matrix-assistant laser desorption ionization-time-of-flight mass spectrometry strategy to compare and identify the mitochondrial protein profiling changes between three breast cell lines with different tumorigenicity and metastasis. The proteomics results demonstrate more than 1,500 protein features were resolved from the equal amount pooled from three purified mitochondrial proteins, and 125 differentially expressed spots were identified by their peptide finger print, in which, 33 identified proteins belonged to mitochondrial proteins. Eighteen out of these 33 identified mitochondrial proteins such as SCaMC-1 have not been reported in breast cancer research to our knowledge. Additionally, mitochondrial protein prohibitin has shown to be differentially distributed in mitochondria and in nucleus for normal breast cells and breast cancer cell lines, respectively. To sum up, our approach to identify the mitochondrial proteins in various stages of breast cancer progression and the identified proteins may be further evaluated as potential breast cancer markers in prognosis and therapy.

Breast cancer genomics: normal tissue and cancer markers

Mammography is a powerful screening tool for early detection of breast cancer, but it has limitations in terms of both specificity and sensitivity. Imaging tools such as MRI that complement mammography are too costly to serve as first-line screens. Recently, progress has been made on blood markers, particularly microRNAs and proteins. There are new methods for protein marker discovery directly in blood, but they are limited in the number of patients that can be examined. An alternative is to discover markers as transcripts in tissues, followed by development of blood protein tests for those that perform best. To identify genes that are overexpressed in malignancy it is paramount to include normal control tissues from healthy individuals. Here we report the identification of potential breast cancer markers, including some that are overexpressed in aggressive disease.

Secretomic and Proteomic Analysis of Potential Breast Cancer Markers by Two-Dimensional Differential Gel Electrophoresis

The transformation of a normal cell into a cancer cell has been correlated with alterations in gene regulation and protein expression. To identify altered proteins and link them to the tumorigenesis of breast cancer, we have distinguished normal breast cells (MCF-10A) from noninvasive breast cancer cells (MCF-7) and invasive breast cancer cells (MB-MDA-231) to identify potential breast cancer markers in transformed breast cells. Using the 2D-DIGE and MALDI-TOF MS techniques, we quantified and identified differentially expressed extracellular secreted proteins and total cellular proteins across MCF-7, MB-MDA-231 and MCF-10A. The proteomic analysis of the secreted proteins identified 50 unique differentially expressed proteins from three different media. In addition, 133 unique differentially expressed proteins from total cellular proteins were also identified. Note that 14 of the secreted proteins and 51 of the total cellular proteins have not been previously reported in breast cancer research. Some of these unreported proteins have been examined in other breast cancer cell lines and have shown positive correlations with 2D-DIGE data. In summary, this study identifies numerous putative breast cancer markers from various stages of breast cancer. The results of this study may aid in developing proteins identified as useful diagnostic and therapeutic candidates in research on cancer and proteomics.

Significance of serum colony-stimulating factor-1 as a breast cancer marker

11071 Background: A specific and sensitive biomarker that indicates the presence of breast cancer is highly desirable, yet available markers are of limited value. Colony-stimulating factor-1 (CSF-1) is involved in mammary gland development and mediates breast cancer progression. Earlier work indicated correlation of serum CSF-1 with breast cancer staging, and a recent report suggests that CSF-1 is a potential breast cancer marker, however the data reported so far await validation. Methods: In a prospective study in 799 women with no history of malignant disease undergoing surgery, serum CSF-1 levels were measured by a commercially available ELISA. In this cohort, 312 patients had breast cancer and 487 age-matched women had benign tumors. The tumor size, nodal and metastasis status, histological tumor type, hormone and human epidermal growth factor receptor 2 (HER2) and menopausal status were evaluated. Mean CSF-1 serum concentrations were compared between the patient groups by non-parametric Wilcoxon two-sample and Kruskal-Wallis test. The area under the receiver operating characteristic curve was calculated by logistic regression. Results: Mean serum CSF-1 concentrations were significantly higher in all patients with malignant tumors (502±429 pg/mL) as compared to those with benign tumors (382±344 pg/mL) (p&lt;0.0001, Wilcoxon). Increased CSF-1 concentrations were significantly related to malignant versus non-malignant disease in logistic regression and receiver operating characteristic analysis (p&lt;0.0001, AUC=0.6). Increased CSF-1 levels in patients with malignant tumors were associated with postmenopausal (p=0.0038) but not premenopausal (p=0.94) status (Wilcoxon). Serum CSF-1 concentrations did not correlate significantly with tumor size, nodal and metastasis status, hormone receptor and HER2 status of patients (Kruskal-Wallis). Conclusions: Our data suggest that serum CSF-1 could serve as a breast cancer marker in postmenopausal women. While its serum levels are not related to breast cancer stage at diagnosis, they might be useful for breast cancer screening in postmenopausal women. No significant financial relationships to disclose.

Selective small molecule inhibitors of the potential breast cancer marker, human arylamine N-acetyltransferase 1, and its murine homologue, mouse arylamine N-acetyltransferase 2

The identification, synthesis and evaluation of a series of rhodanine and thiazolidin-2,4-dione derivatives as selective inhibitors of human arylamine N-acetyltransferase 1 and mouse arylamine N-acetyltransferase 2 is described. The most potent inhibitors identified have submicromolar activity and inhibit both the recombinant proteins and human NAT1 in ZR-75 cell lysates in a competitive manner. 1H NMR studies on purified mouse Nat2 demonstrate that the inhibitors bind within the putative active site of the enzyme.

Use of Glycan Targeting Antibodies To Identify Cancer-Associated Glycoproteins in Plasma of Breast Cancer Patients

Immunoaffinity chromatography (IAC) was used to isolate and identify potential cancer biomarker glycoproteins by targeting disease-associated glycans. Glycoproteins were selected from plasma of disease-free and breast cancer patients with an anti-Lewis x (Le(x)) IAC column. After extensive washing of the IAC column to remove abundant proteins, the selected proteins were eluted with an acidic mobile phase and identified in two ways. The protocol used in route A involved the steps of tryptic digestion, reversed-phase chromatographic fractionation of the digest, and identification of peptides in collected RPC fractions by MALDI-MS/MS. Route B differed in that IAC-selected proteins were further fractionated by reversed-phase chromatography before proteolysis of individual chromatographic fractions and identification by MALDI-MS/MS. Route A was the more efficacious of the two protocols in total number of proteins identified. Of the 26 proteins identified, 9 were found to be potential breast cancer marker candidates based on their elevation in breast cancer patients. The potential of these candidates as cancer markers remains to be validated in much larger, more diverse populations of breast cancer patients.