Spread Of Breast Cancer Cells Research Articles

Tumour immunology: Neutrophils help tumours spread.

Neutrophils support the spread of breast cancer cells to the lungs through the production of leukotrienes.

Suicide Gene-Engineered Stromal Cells Reveal a Dynamic Regulation of Cancer Metastasis.

Cancer-associated fibroblasts (CAFs) are a major cancer-promoting component in the tumor microenvironment (TME). The dynamic role of human CAFs in cancer progression has been ill-defined because human CAFs lack a unique marker needed for a cell-specific, promoter-driven knockout model. Here, we developed an engineered human CAF cell line with an inducible suicide gene to enable selective in vivo elimination of human CAFs at different stages of xenograft tumor development, effectively circumventing the challenge of targeting a cell-specific marker. Suicide-engineered CAFs were highly sensitive to apoptosis induction in vitro and in vivo by the addition of a simple small molecule inducer. Selection of timepoints for targeted CAF apoptosis in vivo during the progression of a human breast cancer xenograft model was guided by a bi-phasic host cytokine response that peaked at early timepoints after tumor implantation. Remarkably, we observed that the selective apoptosis of CAFs at these early timepoints did not affect primary tumor growth, but instead increased the presence of tumor-associated macrophages and the metastatic spread of breast cancer cells to the lung and bone. The study revealed a dynamic relationship between CAFs and cancer metastasis that has counter-intuitive ramifications for CAF-targeted therapy.

Abstract 4130: Dual targeting of VEGF and endoglin inhibits tumor angiogenesis and metastatic spread

Abstract Endoglin, a co-receptor for TGF-β and BMP-9, is highly expressed on angiogenic endothelial cells and has been shown to be a predictive marker for patient survival in various solid tumors. TRC105 is a neutralizing antibody against endoglin which is currently being explored in clinical trials as anti-angiogenic therapy. Previously we have observed upregulation of the endoglin signaling pathway in endothelial cells upon anti-VEGF therapy in rectal cancer patients. In this project we have further explored the redundancy between VEGF and endoglin signaling in endothelial cells and angiogenesis. In addition, we assessed the effect of simultaneously targeting both pathways on breast cancer progression and metastasis. In vitro, inhibition of endoglin signaling by TRC105 caused upregulation of VEGF signaling in human umbilical vein endothelial cells (HUVECs). Using in vitro angiogenesis assays we showed that combined targeting with TRC105 and the VEGF receptor kinase inhibitor SU5416 inhibited angiogenic capacity even further than targeting both pathways separately. To determine the effect of combined targeting in vivo, zebrafish embryos were treated with either TRC105, SU5416 or a combination. Both single treatments resulted in abnormal subintestinal vessel development, while treatment with TRC105 and SU5416 simultaneously increased this effect. Next, we determined whether combined targeting of the endoglin and VEGF pathway could affect tumor growth and metastasis. In a syngeneic model for invasive lobular carcinomas, KEP1-11 breast cancer cells were orthotopically transplanted in mice and tumor growth and metastasis formation were followed over time. Although TRC105 and SU5416 decreased tumor vascular density, tumor volume was not affected. Strikingly, we observed a strong inhibition of metastases in mice treated with TRC105 or a combination of TRC105 and SU5416. In a follow-up experiment, we observed that after resection of the primary tumor, which was accompanied by increased metastatic spread, TRC105 alone already showed a marked decrease in the number of metastases. To further establish the role of endoglin we assessed the effect of endoglin-Fc expression by the tumor cells on tumor growth and metastasis. The extracellular part of endoglin, coupled to the Fc tail of human IgG functions as a ligand trap for endoglin ligands in the circulation. Similar to treatment with TRC105, stable expression of endoglin-Fc significantly decreased vessel density, but did not result in decreased primary tumor formation. Resection of endoglin-Fc expressing tumors lead to drastically less tumor relapse compared to the Fc control group and a complete abrogation of distant metastases was observed. These results imply that targeting endoglin signaling, either with a neutralizing antibody or ligand trap, reduces tumor vessel density or, importantly, inhibits the metastatic spread of breast cancer cells in vivo. Citation Format: Madelon Paauwe, Renier C. Heijkants, Lotte H. Oudt, Gabi W. van Pelt, Cornelis F.M. Sier, Charles P. Theuer, Lukas J.A.C. Hawinkels. Dual targeting of VEGF and endoglin inhibits tumor angiogenesis and metastatic spread. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4130. doi:10.1158/1538-7445.AM2015-4130

"Smart" Nanoparticles Enhance the Cytoplasmic Delivery of Anti-RhoC Silencing RNA and Inhibit the Migration and Invasion of Aggressive Breast Cancer Cells.

Rho-GTPases are small GTP-binding proteins that contribute to the epithelial-to-mesenchymal transition by regulating several cellular processes including organization of the actin cytoskeleton, cell motility, transcription, and cell proliferation. Overexpression of RhoC-GTPases (RhoC) in breast cancer has been implicated in poor disease prognosis due to increased cancer cells invasion, migration, and motility, which warranted its consideration as a therapeutic target for inhibiting breast cancer metastasis. Using silencing RNA (siRNA) molecules to knockdown RhoC expression is a promising approach to inhibit breast cancer metastases. However, transforming anti-RhoC siRNA molecules into a viable therapy remains a challenge due to the lack of a biocompatible carrier that can selectively deliver the RNA cargo into breast cancer cells. We report the use of a degradable, pH-sensitive, β-cyclodextrin (βCD)-based polymeric carrier that condenses anti-RhoC siRNA forming "smart" particles. These smart anti-RhoC particles were efficiently internalized, successfully escaped the endosome, and delivered the RNA cargo into the cytoplasm of SUM149 and MDA-MB-231 breast cancer cells. Our results show that anti-RhoC particles used at a low N/P ratio of 2.5/1 suppressed RhoC protein levels by 100% and 90% in SUM149 and MDA-MB-231 cells, respectively. Further, anti-RhoC particles inhibited the invasion, motility, and migration of SUM149 and MDA-MB-231 cells by 40-47%, 57-60%, and 61.5-73%, respectively. Smart particles encapsulating the scrambled siRNA sequence did not affect RhoC protein expression or the invasion, motility, and migration of SUM149 and MDA-MB-231 cells, which indicate the biocompatibility of the polymeric carrier and selectivity of the observed RhoC knockdown. These results collectively indicate the therapeutic potential of smart anti-RhoC particles in arresting the metastatic spread of breast cancer cells.

Abstract P1-07-02: Mesenchymal stem cell regulated microRNAs converge on the speech gene FOXP2 and regulate breast cancer metastasis

Abstract About 90% of breast cancer mortalities are due to the spread of breast cancer cells (BCCs) from a primary tumor to distant organs, a process known as metastasis. However, the molecular mechanisms underlying metastasis remain poorly understood. Substantial evidence now supports a major role for the tumor microenvironment (TME) in catalyzing breast cancer metastasis. Indeed, observations indicate that proximal interactions between BCCs and cells of the TME induce altered gene expression programs in BCCs, allowing for the navigation of the various steps of the metastatic cascade. Our group and others observed that breast tumors recruit mesenchymal stem cells (MSCs): multipotent fibroblasts that normally exert tissue maintenance functions. We and others have observed that physical interactions of MSCs with BCCs are sufficient to drive their metastatic dissemination in murine xenograft models, via the induction of epithelial-mesenchymal transition (EMT) and dedifferentiation into stem cell-like states (cancer stem cells, or CSCs), states tightly associated with the capacity to seed new tumors (for example in foreign tissues) and with chemotherapeutic resistance. However, the TME-induced molecular pathways regulating such mechanisms remain poorly understood. MicroRNAs (miRNAs, miRs) are small noncoding RNAs that regulate gene expression via base-pair interactions with messenger RNAs (mRNAs), resulting in mRNA degradation or translational inhibition. Due to their ability to interact with large numbers of target mRNAs simultaneously, miRNAs are major regulators of cell identity, and thereby serve critical roles in metastasis. We performed miRnome-wide screening of MSC-stimulated BCCs to determine if TME interactions might contribute to BCC metastasis via the deregulation of miRNAs. We observed that proximal MSCs induce aberrant expression of a specific set of miRNAs in BCCs, which had not been previously implicated in breast cancer pathogenesis. These miRNAs, led by the transcriptionally co-regulated miR-199a-3p and miR-214, were sufficient to actuate the metastasis of weakly metastatic human BCCs in xenograft models. We observed that exogenous expression of the miRNAs provided BCCs with phenotypes and gene markers characteristic of CSCs, including enhanced tumor initiation capacities. Interestingly, we found that the MSC-induced miRNAs function as an interrelated network, and converge upon a common novel target: the speech associated gene FOXP2. Knockdown of FOXP2 phenocopied the metastatic phenotypes observed in MSC-induced miRNA expressing BCCs. Importantly, elevated levels of the MSC-induced miRNAs or depressed levels of FOXP2 could predict patient prognosis in the clinic. Altogether, our results incriminate FOXP2 and it’s MSC-induced miRNA regulatory network as novel determinants of breast cancer metastasis. Citation Format: Benjamin G Cuiffo, Antoine Campagne, George W Bell, Antonio Lembo, Francesca Orso, Evan Lien, Manoj K Bhasin, Monica Raimo, Summer E Hanson, Andriy Marusyk, Peiman Hematti, Kornelia Polyak, Odette Mariani, Stefano Volinia, Anne Vincent-Salomon, Daniela Taverna, Antoine E Karnoub. Mesenchymal stem cell regulated microRNAs converge on the speech gene FOXP2 and regulate breast cancer metastasis [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-07-02.

Hypermethylation of TET1 promoter is a new diagnosic marker for breast cancer metastasis.

Breast cancer metastasis is a major cause of cancer-related death in women. However, markers for diagnosis of breast cancer metastasis are rare. Here, we reported that TET1, a tumor suppressor gene, was downregulated and hypermethylated in highly metastatic breast cancer cell lines. Moreover, silencing of TET1 in breast cancer cells increased the migration and spreading of breast cancer cells. In breast cancer clinical samples, TET1 expression was reduced in LN metastases compared with primary tissues. Besides, the methylation level of the TET1 promoter was increased significantly in LN metastases. Taken together, these findings indicate that promoter hypermethylation may contribute to the downregulation of TET1 and could be used as a promising marker for diagnosis in patients with breast cancer metastasis.

Reciprocity in breast cancer progression.

Reciprocity in breast cancer progression.

Chapter Eight - HAS2 and CD44 in Breast Tumorigenesis

Metastatic spread of breast cancer cells, facilitated by the epithelial-mesenchymal transition (EMT) process, is responsible for the majority of breast cancer mortality. Increased levels of hyaluronan due to deregulation of hyaluronan-synthesizing enzymes, like HAS2, and expression of CD44, the key receptor for hyaluronan, are correlated to poor outcome of patients with basal-like breast cancer. TGFβ induces HAS2 and CD44, both of which are required in the course of efficient TGFβ-induced EMT processes by mammary epithelial cells. Elucidation of the molecular mechanisms underlying tumor-stroma interactions in breast cancer including the regulation of HAS2 and CD44 expression may contribute to the development of better strategies to treat breast cancer patients.

Characterization of Three Full-length Human Nonmuscle Myosin II Paralogs

Nonmuscle myosin IIs (NM IIs) are a group of molecular motors involved in a wide variety of cellular processes including cytokinesis, migration, and control of cell morphology. There are three paralogs of the NM II heavy chain in humans (IIA, IIB, and IIC), each encoded by a separate gene. These paralogs are expressed at different levels according to cell type and have different roles and intracellular distributions in vivo. Most previous studies on NM II used tissue-purified protein or expressed fragments of the molecule, which presents potential drawbacks for characterizing individual paralogs of the intact protein in vitro. To circumvent current limitations and approach their native properties, we have successfully expressed and purified the three full-length human NM II proteins with their light chains, using the baculovirus/Sf9 system. The enzymatic and structural properties of the three paralogs were characterized. Although each NM II is capable of forming bipolar filaments, those formed by IIC tend to contain fewer constituent molecules than those of IIA and IIB. All paralogs adopt the compact conformation in the presence of ATP. Phosphorylation of the regulatory light chain leads to assembly into filaments, which bind to actin in the presence of ATP. The nature of interactions with actin filaments is shown with different paralogs exhibiting different actin binding behaviors under equivalent conditions. The data show that although NM IIA and IIB form filaments with similar properties, NM IIC forms filaments that are less well suited to roles such as tension maintenance within the cell.

Electrochemical genosensor for detection of human mammaglobin in polymerase chain reaction amplification products of breast cancer patients

Human mammaglobin (MG) has been found to be the most specific molecular marker for the hematogenous spread of breast cancer cells. In our study, an electrochemical impedance spectroscopic DNA biosensor was established for the detection of MG in breast cancer patients. The working conditions for the biosensor, such as immobilization time, rinse process, and hybridization process, were optimized. Under the optimal conditions, the charge transfer resistance of the proposed DNA biosensor shows excellent correlation with the amount of the complementary oligonucleotides in the range from 1.0 × 10(-9) to 2.0 × 10(-8) M. The detection limit is 5.0 × 10(-10) M. The proposed biosensor was used to detect the polymerase chain reaction amplification products of actual clinical breast cancer samples. The results were compared with that obtained by conventional gel electrophoresis. The results indicate that the electrochemical impedance spectroscopic assay is significantly sensitive and time-saving. The simple strategy described here is expected to be used in clinical application for early diagnosis of breast cancer.

Abstract 1395: Docetaxel pretreatment is associated with increased incidence of CNS-metastases in a murine model of HER2-positive breast cancer

Abstract Breast cancer is the most frequent neoplasm in females as it affects 1:10 women. In populations of early breast cancer subsequent brain metastases develop in 5%, while in metastatic breast cancer (mBC), the incidence of CNS-metastases reaches 10-16% [Ann Oncol 2006; 17:935]. The incidence is particularly high (30%-50%) in patients (pts) with HER2-positive mBC [Ann Oncol 2008; 19:1837]. Similarly, the incidence of CNS-metastases is high in pts treated with taxanes for mBC [Ann Oncol 2001; 12:353]. Therefore, we aimed to investigate the role of taxanes on CNS metastases in a murine breast cancer model using the MDA-MB-231BR cell line which has a tropism to metastasize into the CNS upon intracardiac injection [J Natl Ca Inst 2008;100:1092]. Groups of Balb/c nude mice were injected intravenously with docetaxel at a dose of 10mg/kg every 2 weeks for 5 injections (long tax, N=17) or with only 2 similar injections (short tax, N=16) or no injection (control, N=14). Two weeks later MDA-MB-231 BR tumor cells (500′000 cells in 0.1mL PBS) were injected into the left ventricle. Four weeks after that, animals were sacrificed for collection of organs and analysis by histology. The main finding was that metastatic foci were significantly increased in long-tax mice (median number of foci 52, range 0-76) compared to control mice (median number of foci 20, range 0-52; p=0.015). In short-tax animals an intermediate incidence of foci was found (median 30, range 0-79), with a trend, but not a significant difference compared to untreated animals (p=0.7) Histologically we observed a mainly perivascular intraparenchymal infiltration pattern while superficial metastases or a spread to the cerebrospinal fluid was only rarely seen. We therefore assessed changes of the blood-brain barrier (BBB) by ultrastructural approaches. However, we have not found obvious differences in the BBB configuration after taxane treatment. In summary, our results provide evidence that taxane treatment might facilitate spread of breast cancer cells into the CNS, however underlying mechanisms remain to be determined. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1395. doi:1538-7445.AM2012-1395

SmgGDS splice variants: Potential novel targets for breast cancer therapeutics.

225 Background: Breast cancer malignancy is promoted by the small GTPases K-Ras, Rap1, RhoA, and Rac1. We recently reported that the activity of these GTPases is regulated by two splice variants of SmgGDS, named SmgGDS-558 and SmgGDS-607. SmgGDS is overexpressed in lung and prostate cancer, but its role in breast cancer is unknown. Here we examine whether SmgGDS splice variants are expressed in breast cancer and promote breast cancer malignancy. Methods: Immunohistochemical staining for SmgGDS was performed on archival human breast tumors (N=183) and normal breast tissue (N=22). Immunoblotting was used to detect SmgGDS splice variants in human breast cancer cell lines. siRNAs that silence different SmgGDS splice variants were used to examine the effects of SmgGDS knockdown on breast cancer cell spreading, cell proliferation via [3H]thymidine uptake, anchorage-independent cell growth using soft agar colony assays, and NF-kB activation using luciferase reporter assays. Results: SmgGDS expression was detected in >65% of DCIS and invasive lobular and ductal carcinoma, and in 100% of metastatic tumors, but was detected in only 18% of normal breast tissue specimens (p<0.01). All tested cell lines expressed both SmgGDS splice variants. Silencing SmgGDS-558 or SmgGDS-607 with siRNA significantly diminished cell proliferation (100±2.0 vs. 11.3±1.0 vs. 50.5±2.2, p<0.05) in MCF-7 cells, with similar results in MDA-MB-231 and T47D cells. MCF-7 soft agar colony formation was significantly decreased 71% and 49% when SmgGDS-558 or SmgGDS-607 was silenced. MCF-7 cell spreading was promoted by silencing SmgGDS-558, but not SmgGDS-607. NF-kB activation was also decreased by 30% in resting and TNF-α-treated MCF-7 and MDA-MB-231 cells by silencing either splice variant. Conclusions: SmgGDS is disproportionally expressed in human breast cancers. Reduction of SmgGDS-558 and SmgGDS-607 levels dramatically reduced breast cancer cell proliferation, soft agar colony formation, and NF-kB activation. Our results indicate that SmgGDS splice variants regulate breast cancer malignancy, most likely through their regulation of small GTPases. This study identifies SmgGDS splice variants as novel therapeutic targets in breast cancer.

SmgGDS splice variants: Potential novel targets for breast cancer therapeutics.

10567 Background: Breast cancer malignancy is promoted by the small GTPases K-Ras, Rap1, RhoA, and Rac1. We recently reported that the activity of these GTPases is regulated by two splice variants of SmgGDS, named SmgGDS-558 and SmgGDS-607. SmgGDS is overexpressed in lung and prostate cancer, but its role in breast cancer is unknown. Here we examine whether SmgGDS splice variants are expressed in breast cancer and promote breast cancer malignancy. Methods: Immunohistochemical staining for SmgGDS was performed on archival human breast tumors (N=183) and normal breast tissue (N=22). Immunoblotting was used to detect SmgGDS splice variants in human breast cancer cell lines. siRNAs that silence different SmgGDS splice variants were used to examine the effects of SmgGDS knockdown on breast cancer cell spreading, cell proliferation via [3H]thymidine uptake, anchorage-independent cell growth using soft agar colony assays, and NF-kB activation using luciferase reporter assays. Results: SmgGDS expression was detected in >65% of DCIS and invasive lobular and ductal carcinoma, and in 100% of metastatic tumors, but was detected in only 18% of normal breast tissue specimens (p<0.01). All tested cell lines expressed both SmgGDS splice variants. Silencing SmgGDS-558 or SmgGDS-607 with siRNA significantly diminished cell proliferation (100±2.0 vs. 11.3±1.0 vs. 50.5±2.2, p<0.05) in MCF-7 cells, with similar results in MDA-MB-231 and T47D cells. MCF-7 soft agar colony formation was significantly decreased 71% and 49% when SmgGDS-558 or SmgGDS-607 was silenced. MCF-7 cell spreading was promoted by silencing SmgGDS-558, but not SmgGDS-607. NF-kB activation was also decreased by 30% in resting and TNF-α-treated MCF-7 and MDA-MB-231 cells by silencing either splice variant. Conclusions: SmgGDS is disproportionally expressed in human breast cancers. Reduction of SmgGDS-558 and SmgGDS-607 levels dramatically reduced breast cancer cell proliferation, soft agar colony formation, and NF-kB activation. Our results indicate that SmgGDS splice variants regulate breast cancer malignancy, most likely through their regulation of small GTPases. This study identifies SmgGDS splice variants as novel therapeutic targets in breast cancer.

Angiogenesis Markers Quantification in Breast Cancer and Their Correlation with Clinicopathological Prognostic Variables

Tumoural angiogenesis is essential for the growth and spread of breast cancer cells. Therefore the aim of this study was to assess the diagnostic performance of angiogenesis markers in tumours and there reflecting levels in serum of breast cancer patients. Angiogenin, Ang2, fibroblast growth factor basic, intercellular adhesion molecule (ICAM)-1, keratinocyte growth factor (KGF), platelet-derived growth factor-BB, and VEGF-A were measured using a FASTQuant angiogenic growth factor multiplex protein assay. We observed that breast cancer tumours exhibited high levels of PDGF-BB, bFGF and VEGF, and extremely high levels of TIMP-1 and Ang-2, whereas in serum we found significantly higher levels of Ang-2, PDGF-BB, bFGF, ICAM-1 and VEGF in patients with breast cancer compared to the benign breast diseases patients. Moreover, some of these angiogenesis markers evaluated in tumour and serum of breast cancer patients exhibited association with standard clinical parameters, ER status as well as MVD of tumours. Angiogenesis markers play important roles in tumour growth, invasion and metastasis. Our results suggest that analysis of angiogenesis markers in tumour and serum of breast cancer patients using multiplex protein assay can improve diagnosis and prognosis in this diseases.

Abstract 1438: Breast cancer metastasis suppressor 1 (BRMS1) suppresses attachment and spreading of breast cancer cells on 2D and 3D extracellular matrix components by altering focal adhesion-associated signaling

Abstract Metastatic dissemination of cancer cells from primary tumor to secondary sites is a multi-step process that depends heavily on the ability of cancer cells to respond to the microenvironmental cues, such as changes in composition of surrounding extracellular matrix (ECM), by adapting their adhesion abilities and undergoing cytoskeletal rearrangement. Many of these interactions between cancer cells and ECM are mediated by signaling cascades initiated at the cell surface through activation of integrins and growth factor receptors. BRMS1, or Breast cancer Metastasis Suppressor 1, belongs to a family of metastasis suppressor genes and has been shown to affect several steps of the metastatic cascade. BRMS1-expressing cells shed by the primary tumor can enter the circulation and reach secondary sites, where they remain largely as single cells. Moreover, ectopic expression of BRMS1 results in a significant decrease in survival of tumor cells within blood stream, increased susceptibility to anoikis and inability to form colonies at secondary organ sites, all events that could be attributed to failure of BRMS1 expressing cells to activate integrins and strongly adhere to ECM components. Here, we show that BRMS1 expression in MDA-MB-231 and MDA-MB-435 cells did not significantly alter expression levels of the integrin monomers tested. However, after short-term (15-30 minutes) plating of cells onto mixed ECM or individual ECM components (collagen I, collagen IV, or fibronectin) under 2D conditions, BRMS1-expressing cells exhibited reduced activation of β1 integrin, focal adhesion kinase (FAK), and scaffolding protein Talin1, as well as a decrease in their localization to focal adhesions. Furthermore, short-term plating of BRMS1-expressing cells on collagens I or IV or fibronectin resulted in marked inhibition of cytoskeletal rearrangement and failure to form cellular adhesion projections, as compared to cells vector-transfected cells. In addition, under 3D conditions, BRMS1-expressing cells remained rounded and failed to reorganize their cytoskeleton even after 24-hour stimulation with serum. Taken together, we believe that these findings demonstrate that BRMS1-expressing breast cancer cells are inherently unable to respond to microenvironment changes, which may explain why they exhibit reduced survival in circulation, increased susceptibility to anoikis, and decreased colonization of secondary sites. YBK was supported in part by NIH T32 (AR047512-09) and DOD CDMRP BCRP Postdoctoral Fellowship (BC096855) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1438. doi:10.1158/1538-7445.AM2011-1438

Human Mammaglobin: A Superior Marker for Reverse-Transcriptase PCR in Detecting Circulating Tumor cells In Breast Cancer Patients

Breast cancer is the most frequent cancer in women in the USA and the second most common cause of death in females who develop cancer. Recently, the detection of circulating tumor cells has emerged as a promising tool for monitoring the progression of clinically occult micrometastases in breast cancer patients. Sensitive molecular techniques, primarily based upon the reverse-transcriptase PCR, using various molecules as markers, have been developed to detect circulating tumor cells. Among those molecules, human mammaglobin mRNA has been found to be the most specific marker for the hematogenous spread of breast cancer cells. In this article, we review the current knowledge regarding the use of reverse-transcriptase PCR for detecting human mammaglobin mRNA as a biomarker for circulating tumor cells in breast cancer patients, and evaluate the clinical implications of human mammaglobin since it was first isolated in 1996.

Reversing Breast Cancer Stem Cell into Breast Somatic Stem Cell

Stem cells have an important role in cell biology, allowing tissues to be renewed by freshly created cells throughout their lifetime. The specific micro-environment of stem cells is called stem cell niche; this environment influences the development of stem cells from quiescence through stages of differentiation. Recent advance researches have improved the understanding of the cellular and molecular components of the micro-environment--or niche--that regulates stem cells. We point out an important trend to the study of niche activity in breast cancers. Breast cancer has long been known to conserve a heterogeneous population of cells. While the majority of cells that make up tumors are destined to differentiate and eventually stop dividing, only minority populations of cells, termed cancer stem cell, possess extensive self renewal capability. These cancer stem cells possess characteristics of both stem cells and cancer cells. Breast cancer stem cells reversal to breast somatic stem cells offer a new therapy, that not only can stop the spread of breast cancer cells, but also can differentiate breast cancer stem cells into normal breast somatic stem cells. These can replace damaged breast tissue. Nevertheless, the complexity of realizing this therapy approach needs further research.

A novel role for BRCA1 in regulating breast cancer cell spreading and motility.

BRCA1 C-terminal (BRCT) domains in BRCA1 are essential for tumor suppressor function, though the underlying mechanisms remain unclear. We identified ezrin, radixin, and moesin as BRCA1 BRCT domain-interacting proteins. Ezrin-radixin-moesin (ERM) and F-actin colocalized with BRCA1 at the plasma membrane (PM) of cancer cells, especially at leading edges and focal adhesion sites. In stably expressing cancer cells, high levels of enhanced green fluorescent protein (EGFP)-BRCA1(1634-1863) acted as a dominant-negative factor, displacing endogenous BRCA1 from the PM. This led to delayed cell spreading, increased spontaneous motility, and irregular monolayer wound healing. MCF-7 cells (intact BRCA1) showed lower motility than HCC1937 cells (truncated BRCA1), but expression of EGFP-BRCA1(1634-1863) in MCF-7 increased motility. Conversely, full-length BRCA1 expression in HCC1937 decreased motility but only if the protein retained ubiquitin ligase activity. We conclude that full-length BRCA1 is important for complete tumor suppressor activity via interaction of its BRCT domains with ERM at the PM, controlling spreading and motility of cancer cells via ubiquitin ligase activity.

5121 The relation between sentinel lymph node micro-metastasis, isolated tumour cells and the final axillary lymph node status after complete dissection

Blood and lymphatic circulation are the major routes during metastatic spread of breast cancer cells. Despite the predictive and prognostic value of bone marrow (BM) micro-metastasis, repeated and frequent BM aspirations may not be easily accepted by patients. We try to establish the role of circulating tumor cells as a predictor for micro-metastasis in BM and sentinel lymph node (SLN) as well as to identify the association between micro-metastasis in blood and lymphatic circulation. We prospectively studied 47 breast cancer patients without overt metastasis. Bilateral BM samples and blood samples were obtained before surgery and subsequently handled using magnetic-activated cell separation (MACS) followed by immunocytochemistry (ICC). SLN was examined by hematoxylin and eosin (H and E) staining and ICC.Blood and BM micro-metastasis were detected in 16 (35%) and 25 (54%) of 47 patients. SLN micro-metastasis were detected in 13 (27.7%) and 22 (46.8%) patients using H and E and ICC, respectively. All the patients with circulating tumor cells had micro-metastasis in BM, whereas 9 of 25 (36%) patients with micro-metastasis in BM had no circulating tumor cells (P < 0.001). On the other hand, there is no correlation between circulating tumor cells and micro-metastasis in SLNs detected by either H and E (P = 0.52) or ICC (P = 0.36). We found that the presence of circulating tumor cells might predict BM micro-metastasis but not SLN micro-metastasis. It is also interesting to find that the presence of SLN micro-metastasis does not necessarily correlate with the presence of micro-metastasis in BM and blood.

5122 Ductal lavage-a tecnhique for the early diagnosis of breast cancer: our experience during the last three years

Blood and lymphatic circulation are the major routes during metastatic spread of breast cancer cells. Despite the predictive and prognostic value of bone marrow (BM) micro-metastasis, repeated and frequent BM aspirations may not be easily accepted by patients. We try to establish the role of circulating tumor cells as a predictor for micro-metastasis in BM and sentinel lymph node (SLN) as well as to identify the association between micro-metastasis in blood and lymphatic circulation. We prospectively studied 47 breast cancer patients without overt metastasis. Bilateral BM samples and blood samples were obtained before surgery and subsequently handled using magnetic-activated cell separation (MACS) followed by immunocytochemistry (ICC). SLN was examined by hematoxylin and eosin (H and E) staining and ICC.Blood and BM micro-metastasis were detected in 16 (35%) and 25 (54%) of 47 patients. SLN micro-metastasis were detected in 13 (27.7%) and 22 (46.8%) patients using H and E and ICC, respectively. All the patients with circulating tumor cells had micro-metastasis in BM, whereas 9 of 25 (36%) patients with micro-metastasis in BM had no circulating tumor cells (P < 0.001). On the other hand, there is no correlation between circulating tumor cells and micro-metastasis in SLNs detected by either H and E (P = 0.52) or ICC (P = 0.36). We found that the presence of circulating tumor cells might predict BM micro-metastasis but not SLN micro-metastasis. It is also interesting to find that the presence of SLN micro-metastasis does not necessarily correlate with the presence of micro-metastasis in BM and blood.