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Long noncoding RNAs (lncRNAs) are frequently precursor RNAs of microRNAs (miRNAs) or act as competing endogenous RNAs (ceRNAs) to interact with miRNAs. To better understand the shared impact of lncRNAs and miRNAs in the regulatory post‐transcriptional network, we focused here on the relationships between (a) lncRNA H19 and miR‐675, (b) NEAT1 and miR‐204, and (c) HOTAIR and miR‐331 in plasma of early breast cancer (BC) patients. We quantified each RNA in plasma samples of 63 BC patients and 10 healthy women by quantitative real‐time PCR. In cell culture experiments, the influence of these noncoding RNAs (ncRNAs) on proliferation and apoptosis of BC cell line MCF‐7 was examined. Plasma levels of H19 (P = 0.030), NEAT1 (P = 0.030), and miR‐331 (P = 0.012) were deregulated in BC patients compared with healthy women. In both cohorts, the concentrations of H19 correlated with those of miR‐675 (P = 0.0001). Higher H19 (P = 0.001) along with lower miR‐675 (P = 0.007) levels and higher miR‐204 (P = 0.017) along with lower NEAT1 (P = 0.030) levels were detected in plasma of HER2‐positive patients compared with the other BC subgroups. Whereas the expression of HOTAIR was below the detection level, miR‐331 levels correlated with nodal status (P = 0.002) and recurrence (P = 0.012). In cell culture experiments, a competitive impact on cell proliferation and apoptosis by these ncRNAs was also documented. Our findings describe a relationship of the plasma levels of H19/miR‐675 and NEAT1/miR‐204 in the different BC subtypes; in addition, they reveal an interplay between these lncRNAs and miRNAs in the regulatory network in MCF‐7 cells, which should also be considered in the search for new diagnostic and therapeutic markers. [ABSTRACT FROM AUTHOR]

Background: The prognostic relevance of circulating tumor cells (CTCs) at the time of primary diagnosis has been well established. However, little information is available regarding their prognostic relevance to follow-up care.Methods: The multicenter, open-label, phase III SUCCESS A trial compared two adjuvant chemotherapy regimens followed by 2 vs 5 years of zoledronate for early-stage, high-risk breast cancer patients. The presence of CTCs was assessed before and 2 years after chemotherapy using the FDA-approved CellSearch System. Overall survival (OS) and disease-free survival (DFS) were analyzed using univariate log-rank tests and multivariable Cox regressions. OS and DFS were measured starting from an assessment of CTCs 2 years after the completion of chemotherapy. All statistical tests were two-sided.Results: The sample included 1087 patients who participated in the translational research program of the SUCCESS A trial and for whom sufficient translational data were available regarding CTC status at baseline and at the 2-year follow-up visit. Two years after chemotherapy, 198 (18.2%) patients were CTC-positive. The median follow-up after this timepoint was 37 months. Cox regressions that included CTC status at baseline revealed that CTC status 2 years after chemotherapy had statistically significant and independent prognostic relevance for OS (hazard ratio [HR] = 3.91, 95% confidence interval [CI] = 2.04 to 7.52, P < .001) and DFS (HR = 2.31, 95% CI = 1.50 to 3.55, P < .001).Conclusion: The presence of CTCs 2 years after chemotherapy was associated with decreased OS and DFS. Based on these results, active individualized surveillance strategies for breast cancer survivors based on biomarkers should be reconsidered. [ABSTRACT FROM AUTHOR]

Purpose: Several studies have provided evidence on the prognostic relevance of circulating tumor cells (CTCs) detected before and after chemotherapy regarding overall survival (OS) and progression-free survival (PFS) in early breast cancer (EBC). We provide data on the prevalence of CTCs 2 and 5 years after primary diagnosis in a cohort of patients with EBC.Methods: The SUCCESS study is a multicenter, prospective, randomized trial comparing PFS in primary breast cancer patients undergoing one of two adjuvant chemotherapy regimens followed by 2 versus 5 years of treatment with zoledronate. CTCs from patients without signs of breast cancer recurrence were analyzed in peripheral blood using the FDA cleared CellSearch® System (Veridex, USA) 2 and 5 years after primary diagnosis.Results: CTCs were detected at 2 and 5 years after primary diagnosis in 96 (16.7%) and 47 (8.2%) of the 574 patients, respectively. There were no associations between CTC status and patient and tumor characteristics or treatment regimens. In 442 (77.0%) patients, no CTCs were detected at either of the two time points, and in 11 patients (1.9%), CTCs were found at both 2 and 5 years after primary diagnosis. In 85 (14.8%) patients, CTCs were present 2 years after primary diagnosis but not after 5 years, while 36 (6.3%) patients had CTCs in their blood only at the 5-year follow-up.Conclusions: In patients with EBC, CTCs can be detected even 5 years after primary diagnosis without clinical signs of disease recurrence. [ABSTRACT FROM AUTHOR]

Background: Recently, the prognostic significance of circulating tumor cells (CTCs) in primary breast cancer as assessed using the Food-and-Drug-Administration-approved CellSearch® system has been demonstrated. Here, we evaluated the prognostic relevance of CTCs, as determined using manually performed immunocytochemistry (MICC) in peripheral blood at primary diagnosis, in patients from the prospectively randomized multicenter SUCCESS-A trial (EudraCT2005000490-21).Methods: We analyzed 23 ml of blood from 1221 patients with node-positive or high risk node-negative breast cancer before adjuvant taxane-based chemotherapy. Cells were separated using a density gradient followed by epithelial cell labeling with the anti-cytokeratin-antibody A45-B/B3, immunohistochemical staining with new fuchsin, and cytospin preparation. All cytospins were screened for CTCs, and the cutoff for positivity was at least one CTC. The prognostic value of CTCs with regard to disease-free survival (DFS), distant disease-free survival (DDFS), breast-cancer-specific survival (BCSS), and overall survival (OS) was assessed using both univariate analyses applying the Kaplan-Meier method and log-rank tests, and using multivariate Cox regressions adjusted for other predictive factors.Results: In 20.6 % of all patients (n = 251) a median of 1 (range, 1-256) CTC was detected, while 79.4 % of the patients (n = 970) were negative for CTCs before adjuvant chemotherapy. A pT1 tumor was present in 40.0 % of patients, 4.8 % had G1 grading and 34.6 % were node-negative. There was no association between CTC positivity and tumor stage, nodal status, grading, histological type, hormone receptor status, Her2 status, menopausal status or treatment. Univariate survival analyses based on a median follow-up of 64 months revealed no significant differences between CTC-positive and CTC-negative patients with regard to DFS, DDFS, BCSS, or OS. This was confirmed by fully adjusted multivariate Cox regressions, showing that the presence of CTCs (yes/no) as assessed by MICC did not predict DFS, DDFS, BCSS or OS.Conclusions: We could not demonstrate prognostic relevance regarding CTCs that were quantified using the MICC method at the time of primary diagnosis in our cohort of early breast cancer patients. Further studies are necessary to evaluate if the presence of CTCs assessed using MICC has prognostic relevance, or can be used for risk stratification and treatment monitoring in adjuvant breast cancer.Trial Registration: The ClinicalTrial.gov registration ID of this prospectively randomized trial is NCT02181101 ; the (retrospective) registration date was June 2014 (study start date September 2005). [ABSTRACT FROM AUTHOR]

Background: Disseminated tumor cells (DTCs) can be detected using ultrasensitive immunocytochemical assays and their presence in the bone marrow can predict the subsequent occurrence of overt metastasis formation and metastatic relapse. Using expression profiling on early stage primary breast tumors, low IRX2 expression was previously shown to be associated with the presence of DTCs in the bone marrow, suggesting a possible role of IRX2 in the early steps of metastasis formation. The purpose of this study is to gain insights into the significance of IRX2 protein function in the progression of breast cancer.Methods: To assess the physiological relevance of IRX2 in breast cancer, we evaluated IRX2 expression in a large breast cancer cohort (n = 1992). Additionally, constitutive IRX2 over expression was established in BT-549 and Hs578T breast cancer cell lines. Subsequently we analyzed whether IRX2 overexpression effects chemokine secretion and cellular motility of these cells.Results: Low IRX2 mRNA expression was found to correlate with high tumor grade, positive lymph node status, negative hormone receptor status, and basal type of primary breast tumors. Also in cell lines low IRX2 expression was associated with mainly basal breast cancer cell lines. The functional studies show that overexpression of the IRX2 transcription factor in basal cell lines suppressed secretion of the pro-metastatic chemokines and inhibited cellular motility but did not influence cell proliferation.Conclusion: Our results imply that the IRX2 transcription factor might represent a novel metastasis associated protein that acts as a negative regulator of cellular motility and as a repressor of chemokine expression. Loss of IRX2 expression could therefore contribute to early hematogenous dissemination of breast cancer by sustaining chemokine secretion and enabling mobilization of tumor cells. [ABSTRACT FROM AUTHOR]

Immune checkpoint regulators such as PD-L1 have become exciting new therapeutic targets leading to long lasting remissions in patients with advanced malignancies. However, in view of the remarkable costs and the toxicity profiles of these therapies, predictive biomarkers able to discriminate responders from non-responders are urgently needed. In the present paper, we provide evidence that PD-L1 is frequently expressed on metastatic cells circulating in the blood of hormone receptor-positive, HER2-negative breast cancer patients. We performed western blot, flow cytometry and immunocytochemical analyses to demonstrate the specificity of the PDL1 antibody used in our study and established immunoscores for PDL1 expression on single tumor cells. We then selected sixteen patients with circulating tumor cells (CTCs) using the CellSearch ® system and found PD-L1 (+) CTCs in 11 patients (68.8%). The fraction of PD-L1 (+) CTCs varied from 0.2 to 100% in individual patients. This is the first report demonstrating the expression of PD-L1 on CTCs. The established CTC/PD-L1 assay can be used for liquid biopsy in future clinical trials for stratification and monitoring of cancer patients undergoing immune checkpoint blockade. [ABSTRACT FROM AUTHOR]

Background: In metastatic breast cancer (MBC), antigen profiles of metastatic tissue and primary tumor differ in up to 20 % of patients. Reassessment of predictive markers, including human epidermal growth factor receptor 2 (HER2) expression, might help to optimize MBC treatment. While tissue sampling is invasive and often difficult to repeat, circulating tumor cell (CTC) analysis requires only a blood sample and might provide an easy-to-repeat, real-time "liquid biopsy" approach. The present retrospective study was conducted to compare HER2 expression in primary tumors, metastatic tissue, and circulating tumor cells (CTCs) from MBC patients and to analyze the potential impact of HER2 overexpression by CTCs on progression-free (PFS) and overall survival (OS) in MBC. Methods: CTC-positive (five or more CTCs/7.5 mL blood; CellSearch®, Janssen Diagnostics) MBC patients starting a new line of systemic treatment were eligible for the study. HER2 status of CTCs was determined by immunofluorescence (CellSearch®). HER2 status of primary (PRIM) and metastatic (MET) tumor tissue was determined by immunohistochemistry. Data were analyzed using descriptive statistics and Kaplan-Meier plots. Results: One hundred seven patients (median age (range) 57 (33-81) years) were included. 100/107 (93 %) patients were followed-up for a median [95 % confidence interval (CI)] of 28.5 [25.1-40.1] months. Of 37/107 (35 %) CTC-HER2-positive patients only 10 (27 %) were PRIM-HER2-positive. 6/46 (13 %) patients were MET-HER2-positive; only 2/10 (20 %) CTC-HER2-positive patients were MET-HER2-positive. Overall accuracy between CTC-HER2 expression and PRIM-HER2 and MET-HER2 status was 69 % and 74 %, respectively. Kaplan-Meier plots of PFS and OS by CTC-HER2 status revealed significantly longer median [95 % CI] PFS of CTC-HER2-positive versus CTC-HER2-negative patients (7.4 [4.7-13.7] versus 4.34 [3.5-5.9] months; p = 0.035). CTC-HER2-positive status showed no significant difference for OS (13.7 [7.7-30.0] versus 8.7 [5.9-15.3] months; p = 0.287). Conclusions: HER2 status can change during the course of breast cancer. CTC phenotyping may serve as an easy-to-perform "liquid biopsy" to reevaluate HER2 status and potentially guide treatment decisions. Further, prospective studies are needed. [ABSTRACT FROM AUTHOR]

Background: Experimental analysis of the metastatic cascade requires suitable model systems which allow tracing of disseminated tumor cells and the identification of factors leading to metastatic outgrowth in distant organs. Such models, especially models using immune-competent mice, are rather scarce. We here analyze tumor cell dissemination and metastasis in an immune-competent transplantable mouse mammary tumor model, based on the SV40 transgenic WAP-T mouse mammary carcinoma model. Methods: We orthotopically transplanted into immune-competent WAP-T mice two tumor cell lines (H8N8, moderately metastatic, and G-2, non-metastatic), developed from primary WAP-T tumors. G-2 and H8N8 cells exhibit stem cell characteristics, form homeostatic, heterotypic tumor cell systems in vitro, and closely mimic endogenous primary tumors after orthotopic transplantation into syngeneic, immune-competent WAP-T mice. Tumor cell transgene-specific PCR allows monitoring of tumor cell dissemination into distinct organs, and immunohistochemistry for SV40 T-antigen tracing of single disseminated tumor cells (DTC). Results: While only H8N8 cell-derived tumors developed metastases, tumors induced with both cell lines disseminated into a variety of organs with similar efficiency and similar organ distribution. H8N8 metastases arose only in lungs, indicating that organ-specific metastatic outgrowth depends on the ability of DTC to re-establish a tumor cell system rather than on invasion per se. Resection of small tumors (0.5 cm3) prevented metastasis of H8N8-derived tumors, most likely due to the rather short half-life of DTC, and thus to shorter exposure of the mice to DTC. In experimental metastasis by tail vein injection, G-2 and H8N8 cells both were able to form lung metastases with similar efficiency. However, after injection of sorted "mesenchymal" and "epithelial" G-2 cell subpopulations, only the "epithelial" subpopulation formed lung metastases. Conclusions: We demonstrate the utility of our mouse model to analyze factors influencing tumor cell dissemination and metastasis. We suggest that the different metastatic capacity of G-2 and H8N8 cells is due to their different degrees of epithelial-mesenchymal plasticity (EMP), and thus the ability of the respective disseminated cells to revert from a "mesenchymal" to an "epithelial" differentiation state. [ABSTRACT FROM AUTHOR]

To study the postulated mutant p53 (mutp53) 'gain of function' effects in mammary tumor development, progression and metastasis, we crossed SV40 transgenic WAP-T mice with mutant p53 transgenic WAP-mutp53 mice. Compared to tumors in monotransgenic WAP-T mice, tumors in bitransgenic WAP-T x WAP-mutp53 mice showed higher tumor grading, enhanced vascularization, and significantly increased metastasis. Bitransgenic tumors revealed a gene signature associated with the oncogenic epithelial-mesenchymal transition pathway (EMT gene signature). In cultures of WAP-T tumor-derived G-2 cancer cells, which are comprised of subpopulations displaying 'mesenchymal' and 'epithelial' phenotypes, this EMT gene signature was associated with the 'mesenchymal' compartment. Furthermore, ectopic expression of mutp53 in G-2 cells sufficed to induce a strong EMT phenotype. In contrast to these in vitro effects, monotransgenic and bitransgenic tumors were phenotypically similar suggesting that in vivo the tumor cell phenotype might be under control of the tumor microenvironment. In support, orthotopic transplantation of G-2 cells as well as of G-2 cells expressing ectopic mutp53 into syngeneic mice resulted in tumors with a predominantly epithelial phenotype, closely similar to that of endogenous primary tumors. We conclude that induction of an EMT gene signature by mutp53 in bitransgenic tumors primarily promotes tumor cell plasticity, that is, the probability of tumor cells to undergo EMT processes under appropriate stimuli, thereby possibly increasing their potential to disseminate and metastasize. [ABSTRACT FROM AUTHOR]

Background: Endocrine treatment is the most preferable systemic treatment in metastatic breast cancer patients that have had an estrogen receptor (ER) positive primary tumor or metastatic lesions, however, approximately 20% of these patients do not benefit from the therapy and demonstrate further metastatic progress. One reason for failure of endocrine therapy might be the heterogeneity of ER expression in tumor cells spreading from the primary tumor to distant sites which is reflected in detectable circulating tumor cells (CTCs). Methods: A sensitive and specific staining protocol for ER, keratin 8/18/19, CD45 was established. Peripheral blood from 35 metastatic breast cancer patients with ER-positive primary tumors was tested for the presence of CTCs. Keratin 8/18/19 and DAPI positive but CD45 negative cells were classified as CTCs and evaluated for ER staining. Subsequently, eight individual CTCs from four index patients (2 CTCs per patient) were isolated and underwent whole genome amplification and ESR1 gene mutation analysis. Results: CTCs were detected in blood of 16 from 35 analyzed patients (46%), with a median of 3 CTCs/7.5 ml. In total, ER-negative CTCs were detected in 11/16 (69%) of the CTC positive cases, including blood samples with only ER-negative CTCs (19%) and samples with both ER-positive and ER-negative CTCs (50%). No correlation was found between the intensity and/or percentage of ER staining in the primary tumor with the number and ER status of CTCs of the same patient. ESR1 gene mutations were not found. Conclusion: CTCs frequently lack ER expression in metastatic breast cancer patients with ER-positive primary tumors and show a considerable intra-patient heterogeneity, which may reflect a mechanism to escape endocrine therapy. Provided single cell analysis did not support a role of ESR1 mutations in this process. [ABSTRACT FROM AUTHOR]

The presence of disseminated tumor cells (DTCs) in bone marrow (BM) identifies breast cancer patients with less favorable outcome. Furthermore, molecular characterization is required to investigate the malignant potential of these cells. This study presents a single-cell array comparative genomic hybridization (SCaCGH) method providing molecular analysis of immunomorphologically detected DTCs. The resolution limit of the method was estimated using the cancer cell line SK-BR-3 on 44 and 244k arrays. The technique was further tested on 28 circulating tumor cells and four hematopoietic cells (HCs) from peripheral blood ( n = 8 patients). The SCaCGH method was finally applied to 24 DTCs, three immunopositive cells morphologically classified as probable HCs from breast cancer patients and five HC controls from BM ( n = 7 patients plus n = 1 healthy donor). The frequency of copy number changes of the DTCs revealed similarities with primary breast tumor samples. Three of the patients had available profiles for DTCs and the corresponding tumor tissue from primary surgery. More than two-third of the analyzed DTCs disclosed equivalent changes, both to each other and to the corresponding primary disease, whereas the rest of the cells showed balanced profiles. The probable HCs revealed either balanced profiles ( n = 2) or changes comparable to the tumor tissue and DTCs ( n = 1), indicating morphological overlap between HCs and DTCs. Similar aberration patterns were visible in DTCs collected at diagnosis and at 3 years relapse-free follow-up. SCaCGH may be a powerful tool for the molecular characterization of DTCs. [ABSTRACT FROM AUTHOR]

There is a growing body of evidence that HER2 status can change during disease recurrence or progression in breast cancer patients. In this context, re-evaluation of HER2 status by assessment of HER2 expression on circulating tumor cells (CTCs) is a strategy with potential clinical application. The aim of this trial was to determine the HER2 status of CTCs in metastatic breast cancer patients comparing two CTC assays. A total of 254 patients with metastatic breast cancer from nine German university breast cancer centers were enrolled in this prospective study. HER2 status of CTCs was assessed using both the FDA-approved CellSearch assay and AdnaTest BreastCancer™. Using the CellSearch assay, 122 of 245 (50%) patients had ≥5 CTCs, and HER2-positive CTCs were observed in 50 (41%) of these patients. Ninety of 229 (39%) patients were CTC positive using AdnaTest BreastCancer, and HER2 positivity rate was 47% (42 of 90). The rate of breast cancer patients with HER2-negative primary tumors but HER2-positive CTCs was 32% (25 of 78) and 49% (28 of 57) using the CellSearch assay and AdnaTest BreastCancer, respectively. Considering only those patients who had CTCs on both tests ( n = 62), concordant results regarding HER2 positivity were obtained in 50% of the patients (31/62) ( P = 0.96, κ = −0.006). HER2-positive CTCs can be detected in a relevant number of patients with HER2 negative primary tumors. Therefore, it will be mandatory to correlate the assay-dependent HER2 status of CTCs to the clinical response on HER2-targeted therapies. [ABSTRACT FROM AUTHOR]

Background: As cell-free circulating DNA exists predominantly as mono- and oligonucleosomes, the focus of the current study was to examine the interplay of circulating nucleosomes, DNA, proteases and caspases in blood of patients with benign and malignant breast diseases. Methods: The concentrations of cell-free DNA and nucleosomes as well as the protease and caspase activities were measured in serum of patients with benign breast disease (n = 20), primary breast cancer (M0, n = 31), metastatic breast cancer (M1, n = 32), and healthy individuals (n = 28) by PicoGreen, Cell Death Detection ELISA, Protease Fluorescent Detection Kit and Caspase-Glo®3/7 Assay, respectively. Results: Patients with benign and malignant tumors had significantly higher levels of circulating nucleic acids in their blood than healthy individuals (p = 0.001, p = 0.0001), whereas these levels could not discriminate between benign and malignant lesions. Our analyses of all serum samples revealed significant correlations of circulating nucleosome with DNA concentrations (p = 0.001), nucleosome concentrations with caspase activities (p = 0.008), and caspase with protease activities (p = 0.0001). High serum levels of protease and caspase activities associated with advanced tumor stages (p = 0.009). Patients with lymph node-positive breast cancer had significantly higher nucleosome levels in their blood than node-negative patients (p = 0.004). The presence of distant metastases associated with a significant increase in serum nucleosome (p = 0.01) and DNA levels (p = 0.04), and protease activities (p = 0.008). Conclusion: Our findings demonstrate that high circulating nucleic acid concentrations in blood are no indicators of a malignant breast tumor. However, the observed changes in apoptosis-related deregulation of proteolytic activities along with the elevated serum levels of nucleosomes and DNA in blood are linked to breast cancer progression. [ABSTRACT FROM AUTHOR]

Background : The aim of the current study was to analyze the involvement of methyl-CpG binding proteins (MBDs) and histone modifications on the regulation of CD44, Cyclin D2, GLIPR1 and PTEN in different cellular contexts such as the prostate cancer cells DU145 and LNCaP, and the breast cancer cells MCF-7. Since global chromatin changes have been shown to occur in tumours and regions of tumour-associated genes are affected by epigenetic modifications, these may constitute important regulatory mechanisms for the pathogenesis of malignant transformation. Methods : In DU145, LNCaP and MCF-7 cells mRNA expression levels of CD44, Cyclin D2, GLIPR1 and PTEN were determined by quantitative RT-PCR at the basal status as well as after treatment with demethylating agent 5-aza-2'- deoxycytidine and/or histone deacetylase inhibitor Trichostatin A. Furthermore, genomic DNA was bisulfite-converted and sequenced. Chromatin immunoprecipitation was performed with the stimulated and unstimulated cells using antibodies for MBD1, MBD2 and MeCP2 as well as 17 different histone antibodies. Results : Comparison of the different promoters showed that MeCP2 and MBD2a repressed promoter-specifically Cyclin D2 in all cell lines, whereas in MCF-7 cells MeCP2 repressed cell-specifically all methylated promoters. Chromatin immunoprecipitation showed that all methylated promoters associated with at least one MBD. Treatment of the cells by the demethylating agent 5-aza-2'-deoxycytidine (5-aza-CdR) caused dissociation of the MBDs from the promoters. Only MBD1v1 bound and repressed methylation-independently all promoters. Real-time amplification of DNA immunoprecipitated by 17 different antibodies showed a preferential enrichment for methylated lysine of histone H3 (H3K4me1, H3K4me2 and H3K4me3) at the particular promoters. Notably, the silent promoters were associated with unmodified histones which were acetylated following treatment by 5-aza-CdR. Conclusions : This study is one of the first to reveal the histone code and MBD profile at the promoters of CD44, Cyclin D2, GLIPR1 and PTEN in different tumour cells and associated changes after stimulation with methylation inhibitor 5- aza-CdR. [ABSTRACT FROM AUTHOR]

Subclinical tumor cell spread, as the putative precursor stage of subsequent solid metastases, can be assessed in breast patients via the detection of disseminated tumor cells (DTC) in bone marrow aspirates or circulating tumor cells (CTC) in the peripheral blood with immunocytochemical and molecular techniques. In the context of a growing number of treatment strategies for cancer patients in the adjuvant setting as well as in the metastatic situation, markers predicting therapy efficacy are urgently needed. The detection of DTC or CTC may become one of the most interesting parameters not just for the prediction of survival or therapy monitoring but also for the characterization and specific targeting of residual tumor cells. Progress in this field now permits clinical studies that should lead to improvements in the treatment of breast cancer patients. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Objective: Tissue inhibitor of metalloproteinases-1 (TIMP-1) has been investigated as a potential tumour marker in breast cancer. Here we investigated the correlation between TIMP-1 in tumour tissue and plasma to evaluate whether TIMP-1 in plasma is actually a surrogate marker for TIMP-1 in primary tumours. Furthermore, we assessed whether increased TIMP-1 levels in plasma could be indicative of tumour progression in patients with advanced breast cancer. Methods: Tumour tissue and preoperatively collected plasma samples from 96 primary breast cancer patients were included together with plasma samples from 46 patients with advanced disease. TIMP-1 levels were measured by ELISA. Results: TIMP-1 levels in plasma (median 81.5 ng/ml, range 41.9–174.9) and tumour tissue (median 25.4 ng/mg of total protein, range 0–110.2) from primary breast cancer patients were not correlated (r = 0.05, p = 0.6). Plasma levels of TIMP-1 in primary breast cancer patients were significantly lower than levels in patients with advanced disease (median 108.7 ng/ml, range 59.7–560.7; p < 0.0001). Conclusions: Our findings suggest that TIMP-1 release into the blood might be controlled by an active mechanism. They also point to plasma TIMP-1 as a potential marker for predicting tumour progression and for monitoring tumour burden in metastatic breast cancer patients. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Breast cancer recurrence is a result of undetected metastasis present at the time of primary patient treatment. More sensitive methods are needed to identify subclinical disease progression to better accompany those increasing advances in early breast cancer screening. Aberrant hypermethylation of tumor-suppressor genes is found frequently in primary breast tumors and has been implicated in disease initiation and progression. Epigenetic characterization of tumor cells may provide highly specific and sensitive molecular surrogates for surveillance. We evaluated whether tumor-associated methylated DNA markers could be identified circulating in bone marrow (BM) aspirates and paired serum samples from 33 early-stage patients undergoing surgery for breast cancer. Quantitative methylation-specific PCR (qMSP) was performed using a selected tumor-related gene panel for RAR-ß2, MGMT, RASSF1A, and APC. Tumor-associated hypermethylated DNA was identified in 7 (21%) of 33 BM aspirates and 9 (27%) serum samples. In three patients both BM and serum were positive for hypermethylation. The most frequently detected hypermethylation marker was RASSF1A occurring in 7 (21%) patients. Concordance was present between gene hypermethylation detected in BM or serum samples, and matched-pair primary tumors. Advanced AJCC stage was associated with an increased incidence of circulating gene hypermethylation. In addition, methylation patterns in the sentinel lymph node (SLN) metastasis corresponded with that of the primary tumor, confirming epigenetic clonality is associated with early tumor dissemination. This study demonstrates the novel finding of tumor-associated epigenetic markers in BM aspirates/blood and their potential role as targets for molecular detection. [ABSTRACT FROM AUTHOR]

Increased levels of circulating DNA have been reported in the blood of cancer patients but not healthy individuals. Tumor-specific genomic aberrations, such as loss of heterozygosity (LOH) and microsatellite instability (MSI), can be detected in this free extracellular DNA. Identification of these genetic aberrations may play an important role in cancer diagnosis and prediction of disease progression, Moreover, the genomic regions involved might harbor potential targets for therapies. To evaluate the incidence of microsatellite alterations in circulating DNA, we assessed the blood serum of 34 patients with primary (n = 8) and metastatic (n = 24) breast cancer. Samples were also analyzed for the presence of circulating tumor cells using an immunocytological cytokeratin assay, and the concentration of the tumor marker CA 15-3 was determined. Cenomic DNA extracted from serum and normal blood leukocytes, as a control, was amplified by the polymerase chain reaction using markers at 4 microsatellite loci of chromosomes 10q22-23, 16q22-23, 17q11-12, and 17q21. In 17 of 34 cancer patients, tumor-specific alterations were detected in serum samples. In 16 patients, LOH at various loci was observed, whereas MSI was only detected in the serum of one patient. The pattern of LOH was very heterogeneous, and LOH was detected at chromosomal loci 10q22-23, 16q22- 23, and 17q11-12 but not 17q21. No correlation was found between the detection of circulating tumor DNA and the presence of circulating tumor cells in the blood or serum concentration of CA 15-3. In conclusion, genomic aberrations on chromosomes 10, 16, and 17 are frequent in the circulating DNA of breast cancer patients. However, circulating tumor DNA does not reflect the presence of tumor cells in blood or the level of tumor-associated protein markers such as CA 15-3. Thus, screening for circulating tumor DNA may provide additional diagnostic information. [ABSTRACT FROM AUTHOR]

Background: Cytokeratins are specific markers of epithelial cancer cells in bone marrow. We assessed the influence of cytokeratin-positive micrometastases in the bone marrow on the prognosis of women with breast cancer.Methods: We obtained bone marrow aspirates from both upper iliac crests of 552 patients with stage I, II, or III breast cancer who underwent complete resection of the tumor and 191 patients with nonmalignant disease. The specimens were stained with the monoclonal antibody A45-B/B3, which binds to an antigen on cytokeratins. The median follow-up was 38 months (range, 10 to 70). The primary end point was survival.Results: Cytokeratin-positive cells were detected in the bone marrow specimens of 2 of the 191 control patients with nonmalignant conditions (1 percent) and 199 of the 552 patients with breast cancer (36 percent). The presence of occult metastatic cells in bone marrow was unrelated to the presence or absence of lymph-node metastasis (P=0.13). After four years of follow-up, the presence of micrometastases in bone marrow was associated with the occurrence of clinically overt distant metastasis and death from cancer-related causes (P<0.001), but not with locoregional relapse (P=0.77). Of 199 patients with occult metastatic cells, 49 died of cancer, whereas of 353 patients without such cells, 22 died of cancer-related causes (P<0.001). Among the 301 women without lymph-node metastases, 14 of the 100 with bone marrow micrometastases died of cancer-related causes, as did 2 of the 201 without bone marrow micrometastases (P<0.001). The presence of occult metastatic cells in bone marrow, as compared with their absence, was an independent prognostic indicator of the risk of death from cancer (relative risk, 4.17; 95 percent confidence interval, 2.51 to 6.94; P<0.001), after adjustment for the use of systemic adjuvant chemotherapy.Conclusions: The presence of occult cytokeratin-positive metastatic cells in bone marrow increases the risk of relapse in patients with stage I, II, or III breast cancer. [ABSTRACT FROM AUTHOR]

Pharmaceutical adjuvants, biological markers, cancer care facilities, follow-up, germany, gynecology, happiness, hospitals, university, mammography, models, statistical, neoplasm, residual, obstetrics and gynecology department, survivors, neoplasms, obstetrics, patient prognosis, survival, breast cancer, tumor marker, exhaled breath condensate, community, circulating tumor cells, early diagnosis, datasets, liquid biopsy, chemotherapy regimen, physical examination, academic medical centers, immunologic adjuvants. [Extracted from the article]

Simple Summary: Metastasis is the leading cause of death in breast cancer, and it can be predicted by the detection of circulating tumor cells in the blood and disseminated tumor cells in the bone marrow, which are usually detected by epithelial marker proteins. However, tumor cells with mesenchymal attributes down-regulate the expression of epithelial marker proteins, and are therefore difficult to detect. Here, we found that the protein-cysteine–rich angiogenetic inducer 61 (Cyr61) is strongly expressed in tumor cells with mesenchymal attributes. Cyr61 expression was undetectable in normal blood cells, suggesting that Cyr61 might represent a tumor-associated protein. Functional experiments showed that the loss of Cyr61 reduces the viability of breast tumor cells. Thus, Cyr61 might represent an interesting anti-metastatic target that needs to be explored in future studies. (1) Background: the early detection of cancer cells in the blood or bone marrow of breast cancer patients improves the understanding of metastasis. Disseminating tumor cells in the bone marrow with a pronounced manifestation of mesenchymal markers (mDTC) are difficult to detect by epithelial markers, but they are relevant in the initiation of metastasis. (2) Methods: the breast cancer mDTC cell line BC-M1 was analyzed by mass spectrometry, which revealed high levels of the protein-cysteine–rich angiogenic inducer 61 (Cyr61). The function of Cyr61 was investigated using shRNA and hypoxia. Peripheral blood samples from 35 breast cancer patients were investigated for CTCs defined as cytokeratin-positive/CD45-negative cells. (3) Results: the Cyr61 levels are elevated in mDTC lines from breast, lung, and prostate cancer patients. The loss of Cyr61 resulted in the diminished expression of hypoxia-inducible factor 1-alpha, and increased apoptosis. Cyr61 was present in 47 (43%) of the 109 detected circulating tumor cells (CTCs), while the blood and bone marrow cells from healthy controls were Cyr61-negative. (4) Conclusions: Cyr61 is expressed in mDTC lines, supports the viability of cancer cells, and classifies a new subset of cytokeratin-positive CTCs, which deserves further investigation. [ABSTRACT FROM AUTHOR]

Detection of circulating tumor cells (CTC) can distinguish between aggressive and indolent metastatic disease in breast cancer patients and is thus considered an independent, negative prognostic factor. A clear decline in CTCs is observed in patients who respond to systemic therapy. Nevertheless, CTCs can decrease in patients experiencing disease progression during systemic therapy, too. This study aims to determine the differences between CTC decline in patients responding to therapy and those in whom disease is progressing. Therefore, CTC values were compared at the start and after one cycle of a new line of systemic therapy. In all, 108 initially CTC-positive patients (with ≥5 intact CTCs in 7.5 mL blood) were enrolled in this study and intact and apoptotic CTCs were measured via the CellSearch® system. A cut-off analysis was performed using Youden's J statistics to differentiate between CTC change in the two groups. Here, 64 (59.3%) patients showed stable disease or partial response vs. 44 (40.7%) presenting disease progression. Median overall survival was 23 (range: 4–92) vs. 7 (2–43) months (p < 0.001). Median intact CTC count at enrollment was 15.0 (5–2760) vs. 30.5 (5–200000) cells (p = 0.39) and 2.5 (0–420) vs. 8.5 (0–15000) cells after one cycle of systemic therapy (p = 0.001). Median apoptotic CTC count at enrollment was 10.5 (0–1500) vs. 9 (0–800) cells (p = 0.475) and 1 (0–200) vs. 3 (0–250) cells after one cycle of systemic therapy (p = 0.01). A 50% reduction in baseline apoptotic CTC count represents the optimal cut-off to differentiate between therapy response and disease progression. An apoptotic CTC reduction of ≤10% is 74% specific for early disease progression. [ABSTRACT FROM AUTHOR]

The capture of circulating tumor cells (CTCs) is still a challenging application for microfluidic chips, as these cells are rare and hidden in a huge background of blood cells. Here, different microfluidic ceiling designs in regard to their capture efficiency for CTCs in model experiments and more realistic conditions of blood samples spiked with a clinically relevant amount of tumor cells are evaluated. An optimized design for the capture platform that allows highly efficient recovery of CTCs from size‐based pre‐enriched samples under realistic conditions is obtained. Furthermore, the viability of captured tumor cells as well as single cell recovery for downstream genomic analysis is demonstrated. Additionally, the authors' findings underline the importance of evaluating rational design rules for microfluidic devices based on theoretical models by application‐specific experiments. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

Clinical tumor dormancy is specified as an extended latency period between removal of the primary tumor and subsequent relapse in a cancer patient who has been clinically disease-free. In particular, patients with estrogen receptor-positive breast cancer can undergo extended periods of more than five years before they relapse with overt metastatic disease. Recent studies have shown that minimal residual disease in breast cancer patients can be monitored by different liquid biopsy approaches like analysis of circulating tumor cells or cell-free tumor DNA. Even though the biological principles underlying tumor dormancy in breast cancer patients remain largely unknown, clinical observations and experimental studies have identified emerging mechanisms that control the state of tumor dormancy. In this review, we illustrate the latest discoveries on different molecular aspects that contribute to the control of tumor dormancy and distant metastatic relapse, then discuss current treatments affecting minimal residual disease and dormant cancer cells, and finally highlight how novel liquid biopsy based diagnostic methodologies can be integrated into the detection and molecular characterization of minimal residual disease. [ABSTRACT FROM AUTHOR]

Introduction: There is a multitude of assays for the detection of circulating tumor cells (CTCs) but a very limited number of studies comparing the clinical relevance of results obtained with different test methods. The DETECT trial for metastatic breast cancer patients was designed to directly compare the prognostic impact of two commercially available CTC assays that are prominent representatives of immunocytochemical and RT-PCR based technologies.Methods: In total, 254 metastatic breast cancer patients were enrolled in this prospective multicenter trial. CTCs were assessed using both the AdnaTest Breast Cancer and the CellSearch system according to the manufacturers' instructions.Results: With the CellSearch system, 116 of 221 (50%) evaluable patients were CTC-positive based on a cut-off level at 5 or more CTCs. The median overall survival (OS) was 18.1 months in CTC-positive patients. (95%-CI: 15.1-22.1 months) compared to 27 months in CTC-negative patients (23.5-30.7 months; p<0.001). This prognostic impact for OS was also significant in the subgroups of patients with triple negative, HER2-positive and hormone receptor-positive/HER2-negative primary tumors. The progression free survival (PFS) was not correlated with CTC status in our cohort receiving different types and lines of systemic treatment (p = 0.197). In multivariate analysis, the presence of CTCs was an independent predictor for OS (HR: 2.7, 95%-CI: 1.6-4.2). When the AdnaTest Breast was performed, 88 of 221 (40%) patients were CTC-positive. CTC-positivity assessed by the AdnaTest Breast had no association with PFS or OS.Conclusions: The prognostic relevance of CTC detection in metastatic breast cancer patients depends on the test method. The present results indicate that the CellSearch system is superior to the AdnaTest Breast Cancer in predicting clinical outcome in advanced breast cancer.Trial Registration: Current Controlled Trials Registry number ISRCTN59722891. [ABSTRACT FROM AUTHOR]

A response by Carina Roth and colleagues is presented to a letter to the editor by H.M. Heneghan about their article "Circulating microRNAs as blood-based markers for patients with primary and metastatic breast cancer" in a previous issue.

In breast cancer, over one third of all patients harbor a somatic mutation in the PIK3CA gene, encoding the p110α catalytic subunit of the phosphatidylinositol 3-kinase (PI3K) in their tumor cells. Circulating tumor cells (CTCs) are cells shed from the primary tumor into the blood stream. Recently, the long-term stable breast cancer CTC-ITB-01 cell line with tumorigenic and metastatic capacity was established from liquid biopsy derived cells. The oncogenic hotspot PIK3CA mutation H1047R (kinase domain) was detected in the primary tumor, CTCs and metastasis of the same patient. Other PIK3CA mutations located within the C2 domain (E418K and E453K) were detected in the CTCs and the vaginal metastasis but not in the primary tumor. The goal of our study was to functionally characterize the impact of the rare E418K and E453K mutations within the C2 domain that were not detected in the primary tumor. PIK3CA mutations E418K, E453K, H1047R were generated by site-directed mutagenesis and stably overexpressed in breast cancer cells by lentiviral transduction. Subsequent signaling pathway activation was examined by western blot analysis. The impact of PIK3CA mutations on biological processes was studied by live cell imaging using the Incucyte Zoom system. Structural modeling was conducted in Pymol. The membrane localization of the mutants was evaluated by separating the cytosolic and membrane fraction using ultracentrifugation. Drug susceptibility of CTC-ITB-01 cells was analyzed by live cell imaging. Western blot analysis of human MDA-MB-231, MCF-7 and T47D breast cancer cells stably overexpressing either the PIK3CA wildtype (WT) or one of the E418K, E453K or H1047R mutants revealed a significant increase in AKT phosphorylation in both C2 mutants (E418K and E453K) and the kinase domain mutant H1047R. Functional analysis showed a significantly increased proliferation of MDA-MB-231 cells overexpressing the E453K and H1047R mutants. Migration was increased in all cells overexpressing WT and each of the mutants. Interestingly, invasion and chemotaxis were only enhanced in the MDA-MB-231 cells overexpressing the C2 domain mutants, i.e. E418K and E453K. In addition, membrane localization of the two C2 domain mutants was increased. Structural modeling of the E453K mutation suggests a disruption of the interaction between the negative regulatory domain of the p85α subunit and the p110α catalytic subunit as a potential mechanism leading to the observed activation of PI3K/AKT/mTOR signaling. Dual targeting of AKT/mTOR pathway by MK2206 and RAD001 leads to very strong synergistic effects (IC 50 MK2206: 148 nM, IC 50 RAD001: 15 nM) with respect to proliferation in the CTC-ITB-01 line through apoptosis induction. Our results demonstrate that PIK3CA C2 domain mutations activate PI3K downstream AKT signaling and can increase proliferation, migration and invasion after stable lentiviral transduction. Although both investigated mutations - E418K and E453K - are located within the C2 domain, a different molecular mechanism can be proposed. The PIK3CA mutated CTC-ITB-01 shows a high susceptibility against dual inhibition of AKT/mTOR. Further studies are required to fully elucidate the oncogenic potential of rare PIK3CA mutations. • PIK3CA C2 domain mutations are rare mutations with unknown impact in breast cancer. • The PIK3CA E418K and E453K mutation have been detected in CTCs and metastatic cells. • Both C2 domain mutations activate PI3K/AKT/mTOR pathway signaling through AKT. • For the E453K mutation, a disruption of p85α/p110α interaction can be proposed. • CTC-ITB-01 cells show a high susceptibility for dual targeting of AKT and mTOR. [ABSTRACT FROM AUTHOR]

Tumor cell dissemination appears even in patients with small solid tumors, and bone marrow (BM) is a common homing organ for disseminated tumor cells (DTC) derived from various types of primary epithelial tumors. Tumor cells are frequently detected in the BM of cancer patients without any clinical or even histopathological signs of overt metastases. It is crucial, however, to improve and standardize methods for the detection of DTC. The characterization of DTC has shed new light on the process underlying early tumor cell dissemination and metastatic progression in cancer patients. Characterization of DTC should help to identify novel targets for biological therapies aimed at preventing metastatic relapse and to monitor the efficacy of these therapies. Evidence has emerged that the detection of DTC and circulating tumor cells (CTC) in blood may provide important prognostic information and, in addition, might help to monitor the efficacy of therapy. In this article, we summarize the clinical background and the technical aspects of current methods used for the detection and characterization of DTC in BM and CTC in blood, with a special focus on breast cancer. [Copyright &y& Elsevier]