Spread Of Breast Cancer Cells Research Articles

Iridium(III) carbene complexes as potent girdin inhibitors against metastatic cancers

Many cancer-driving protein targets remain undruggable due to a lack of binding molecular scaffolds. In this regard, octahedral metal complexes with unique and versatile three-dimensional structures have rarely been explored as inhibitors of undruggable protein targets. Here, we describe antitumor iridium(III) pyridinium-N-heterocyclic carbene complex 1a, which profoundly reduces the viability of lung and breast cancer cells as well as cancer patient-derived organoids at low micromolar concentrations. Compound 1a effectively inhibits the growth of non-small-cell lung cancer and triple-negative breast cancer xenograft tumors, impedes the metastatic spread of breast cancer cells, and can be modified into an antibody-drug conjugate payload to achieve precise tumor delivery in mice. Identified by thermal proteome profiling, an important molecular target of 1a in cellulo is Girdin, a multifunctional adaptor protein that is overexpressed in cancer cells and unequivocally serves as a signaling hub for multiple pivotal oncogenic pathways. However, specific small-molecule inhibitors of Girdin have not yet been developed. Notably, 1a exhibits high binding affinity to Girdin with a Kd of 1.3 μM and targets the Girdin-linked EGFR/AKT/mTOR/STAT3 cancer-driving pathway, inhibiting cancer cell proliferation and metastatic activity. Our study reveals a potent Girdin-targeting anticancer compound and demonstrates that octahedral metal complexes constitute an untapped library of small-molecule inhibitors that can fit into the ligand-binding pockets of key oncoproteins.

Combined effects of naringin and doxorubicin on the JAK/STAT signaling pathway reduce the development and spread of breast cancer cells

Breast cancer therapy options are limited due to its late diagnosis and poor prognosis. Doxorubicin is the fundamental therapy approach for this disease. Because chemotherapy has numerous adverse effects, the scope of the existing research was to appraise the synergetic effect of doxorubicin and naringin and explore the underlying mechanism. The cytotoxicity of doxorubicin and naringin on MCF-7 was monitored. Furthermore, the expression of STAT3 and JAK1 as well as the apoptotic and metastatic related genes (Bax, Bcl-2, Survivin, and VEGF) were conducted by immunoblotting assay and qRT-PCR. In addition, a wound healing test was utilized to appraise the migration and metastasis of MCF-7. Our results revealed that naringin and doxorubicin had a synergetic inhibitory influence on MCF-7 cells growth and migration. The synergetic action of doxorubicin and naringin effectively hindered the expression of STAT3, JAK1, Bcl-2, Survivin, and VEGF, with a boost in the level of Bax compared to cells treated with either doxorubicin or naringin. In conclusion, our findings imply that combining doxorubicin with naringin may be a favorable strategy for inhibiting the growth of breast cancer.

Cytoskeleton remodeling induced by SMYD2 methyltransferase drives breast cancer metastasis

Malignant forms of breast cancer refractory to existing therapies remain a major unmet health issue, primarily due to metastatic spread. A better understanding of the mechanisms at play will provide better insights for alternative treatments to prevent breast cancer cell dispersion. Here, we identify the lysine methyltransferase SMYD2 as a clinically actionable master regulator of breast cancer metastasis. While SMYD2 is overexpressed in aggressive breast cancers, we notice that it is not required for primary tumor growth. However, mammary-epithelium specific SMYD2 ablation increases mouse overall survival by blocking the primary tumor cell ability to metastasize. Mechanistically, we identify BCAR3 as a genuine physiological substrate of SMYD2 in breast cancer cells. BCAR3 monomethylated at lysine K334 (K334me1) is recognized by a novel methyl-binding domain present in FMNLs proteins. These actin cytoskeleton regulators are recruited at the cell edges by the SMYD2 methylation signaling and modulate lamellipodia properties. Breast cancer cells with impaired BCAR3 methylation lose migration and invasiveness capacity in vitro and are ineffective in promoting metastases in vivo. Remarkably, SMYD2 pharmacologic inhibition efficiently impairs the metastatic spread of breast cancer cells, PDX and aggressive mammary tumors from genetically engineered mice. This study provides a rationale for innovative therapeutic prevention of malignant breast cancer metastatic progression by targeting the SMYD2-BCAR3-FMNL axis.

L-theanine mechanism and application in the treatment of breast cancer

Breast cancer has been recognized as the leading cancer worldwide and is one of the most common diseases among women, with an incidence rate of up to 7.7%. The pathogenesis of breast cancer can be categorized into congenital and acquired factors, including epigenetics and mutations. The occurrence of breast cancer is closely related to acquired factors such as environment, emotions, and diet. Numerous studies have demonstrated that L-theanine in tea can intervene in the growth and spread of breast cancer cells, thus playing a role in the treatment and prevention of breast cancer. This article provides an overview of the current research on the prevention and treatment of breast cancer using L-theanine, and also prospects the future development and application of L-theanine.

Pingxiao capsule inhibits lung metastasis of triple-negative breast cancer and sensitizes breast cancer to radiotherapy.

To investigate the anticancer effect of Pingxiao capsule (, PXC) on the treatment of breast cancer and . The inhibition of PXC on cell viability and proliferation was determined by cell counting kit-8, EdU assay and colony formation assay, respectively. The effect of PXC on cell apoptosis was detected by using flow cytometry. The suppression of PXC on cell migration and invasion was investigated by chamber assay. To investigate the underlying molecular mechanisms, the expression of proteins related to epithelial to mesenchymal transition (EMT) was analyzed by Western blotting in breast cancer cells and by immunohistochemistry in tumor tissues. The anticancer effect of PXC was evaluated by using MDA-MB-231 xenograft model and 4T1 metastatic breast cancer model. Our results indicated that triple-negative breast cancer (TNBC) cell lines MDA-MB-231 and MDA-MB-468 were sensitive to PXC. PXC potently inhibited the proliferation, colony formation, migration, and invasion of MDA-MB-231 and MDA-MB-468 cells . Then, MDA-MB-231 xenograft model depicted that PXC significantly reduced tumor size and weight compared with Control. 4T1 lung metastasis model showed that PXC significantly inhibited breast cancer cell spreading to lungs in mice. Mechanistically, PXC inhibited EMT process by reducing cadherin turnover in TNBC. Furthermore, PXC in combination with 8 Gy X-ray treatment obviously promoted the induction of apoptosis, and suppressed cell proliferation. PXC could inhibit the proliferation and invasion of TNBC both and , and exerted its anti-metastatic effect by regulating cadherin turnover, Furthermore, it sensitized the TNBC cells to radiotherapy. The data supported further development of PXC as an adjuvant-therapy agent for TNBC.

Immunohistochemical expression of Hairy and Enhancer of Split 1 (HES1) protein in breast carcinoma

Background Hairy and Enhancer of Split 1 (HES1) is a transcription factor involved in cell differentiation, proliferation, and in various cancer progression. Recently, HES1 was addressed as a potential biomarker that induces stem cell features in breast cancer and stimulates epithelial-mesenchymal transition in triple-negative breast cancer (TNBC). Aim This study aimed to assess HES1 immunohistochemical (IHC) expression in invasive breast carcinoma and correlate it with the clinicopathological variables and different molecular subtypes of the cases. Patients and methods IHC was conducted on 76 paraffin blocks with an anti-HES1 monoclonal antibody, and a final IHC score was calculated based on staining intensity and percentage of positively stained cells. A final IHC of greater than or equal to 4 was considered an HES1 positive expression. Results HES1 expression was positive in 18 (23.7%) cases and was significantly associated with breast cancer HER2-enriched molecular subtype, followed by triple-negative breast cancer (P<0.05). HES1 expression was also significantly associated with estrogen and progesterone receptor negativity and HER2 overexpression (P<0.05). Positive HES1 expression was associated with high tumor grade, advanced stage, high Ki-67 proliferation index, and presence of tumor vascular emboli, although it did not reach statistical significance (P>0.05). Conclusion Our study demonstrated that the HES1 protein showed a significantly higher expression in nonluminal breast cancer subtypes. In addition, it could have a potential role in the growth and spread of breast cancer cells. These findings suggest that HES1 is a possible promising target for therapeutic interventions.

Withaferin A inhibits breast cancer-induced osteoclast differentiation.

Bone is the most prone to metastatic spread of breast cancer cells for each subtype of the disease. Bone metastasis-related complications including severe pain and pathological fractures affect patients' quality of life. Current treatment options including surgery, radiation, and bone-targeted therapies (e.g., bisphosphonates) are costly or have serious adverse effects such as renal toxicity and osteonecrosis of the jaws. Therefore, a safe, inexpensive, and efficacious agent for prevention of breast cancer bone metastasis is urgently needed. Our previously published RNA sequencing analysis revealed that many genes implicated in bone remodeling and breast cancer bone metastasis were significantly downregulated by treatment with withaferin A (WA), which is a promising cancer chemopreventive agent derived from a medicinal plant (Withania somnifera). The present study investigated whether WA inhibits breast cancer induction of osteoclast differentiation. At plasma achievable doses, WA treatment inhibited osteoclast differentiation (osteoclastogenesis) induced by three different subtypes of breast cancer cells (MCF-7, SK-BR-3, and MDA-MB-231). WA and the root extract of W. somnifera were equally effective for inhibition of breast cancer induction of osteoclast differentiation. This inhibition was accompanied by suppression of interleukin (IL)-6, IL-8, and receptor activator of nuclear factor-κB ligand, which are pivotal osteoclastogenic cytokines. The expression of runt-related transcription factor 2, nuclear factor-κB, and SOX9 transcription factors, which positively regulate osteoclastogenesis, was decreased in WA-treated breast cancer cells as revealed by confocal microscopy and/or immunoblotting. Taken together, these data suggest that WA could be a promising agent for prevention of breast cancer-induced bone metastasis.

The Heparan Sulfate Proteoglycan Syndecan-1 Triggers Breast Cancer Cell-Induced Coagulability by Induced Expression of Tissue Factor.

Syndecan-1 (Sdc-1) upregulation is associated with poor prognosis in breast cancer. Sdc-1 knockdown results in reduced angiogenesis and the dysregulation of tissue factor (TF) pathway constituents. Here, we evaluate the regulatory mechanisms and functional consequences of the Sdc-1/TF-axis using Sdc-1 knockdown and overexpression approaches in MCF-7 and MDA-MB-231 breast cancer cells. Gene expression was analyzed by means of qPCR. Thrombin generation and cell migration were detected. Cell-cycle progression and apoptosis were investigated using flow cytometry. In MDA-MB-231 cells, IL6, IL8, VEGF, and IGFR-dependent signaling affected TF pathway expression depending on Sdc-1. Notably, Sdc-1 depletion and TF pathway inhibitor (TFPI) synergistically affected PTEN, MAPK, and STAT3 signaling. At the functional level, the antiproliferative and pro-apoptotic effects of TFPI depended on Sdc-1, whereas Sdc-1's modulation of cell motility was not affected by TFPI. Sdc-1 overexpression in MCF-7 and MDA-MB-231 cells led to increased TF expression, inducing a procoagulative phenotype, as indicated by the activation of human platelets and increased thrombin formation. A novel understanding of the functional interplay between Sdc-1 and the TF pathway may be compatible with the classical co-receptor role of Sdc-1 in cytokine signaling. This opens up the possibility of a new functional understanding, with Sdc-1 fostering coagulation and platelet communication as the key to the hematogenous metastatic spread of breast cancer cells.

Abstract P6-14-03: Oestrogen represses Noggin expression by interfering BMP/Smad signalling in ER positive breast cancer cells

Abstract Background Bone morphogenetic proteins (BMPs) are members of Transforming Growth Factor β (TGF-β) superfamily. BMPs are actively involved in the disease progression and bone metastasis of breast cancer. As a natural antagonist of BMP, Noggin plays important roles in the regulation of BMP signalling. It can facilitate spread of breast cancer cells to bone and subsequent colonisation and formation of osteolytic bone lesions. The present study aimed to investigate the regulatory mechanism for Noggin expression in oestrogen receptor (ER) positive breast cancer cells. Method Noggin expression was analysed in The Cancer Genome Atlas (TCGA ER (+) n=763, ER (-) n=216) and E-MTAB-6703 (ER (+) n=733, ER (-) n=421) cohorts. Correlation between Noggin and ER was evaluated using Spearman test. The expression of Noggin in an ER positive breast cancer cell line MCF-7 was determined by depriving the cells from oestrogen using phenol red-free DMEM supplemented with 10% charcoal stripped foetal calf serum or adding 10-10M 17-β-oestradiol. Activation of Smad-1/5/8 and involvement of BMP receptors in the oestrogen repressed Noggin expression were further examined using recombinant human BMP7 and a BMP receptor inhibitor (LDN-193189). Influence of Noggin on cellular functions was evaluated in MCF-7 cells with Noggin overexpression using a lentiviral Noggin expression vector. Results Noggin expression was negatively correlated with ERα in both TCGA BRCA (r=-0.162, p<0.01, n=1093) and E-MTAB-6703 (r=-0.078, p<0.01, n=2302) cohorts. The expression of Noggin was increased in the MCF-7 cells upon a deprivation from oestrogen which was further validated by adding 17-β-oestradiol. This is in line with the increased expression of Noggin observed in the MCF-7 cells with ER silencing (GSE27473). Furthermore, an increased level of phosphorylated Smad1/5/8 was seen in the MCF-7 being hungered from oestrogen which was prevented by adding 17-β-oestradiol and LDN-193189, respectively. As a result, the oestrogen hunger induced Noggin expression was also decreased by adding with 17-β-oestradiol and LDN-193189. To further investigate the influence of oestrogen on BMP-Smad signalling regulated Noggin expression, Noggin expression and phosphorylation of Smad1/5/8 and Smad3 were determined in MCF-7 cells which were treated with rhBMP7 and in combination with 17-β-oestradiol and LDN-193189, respectively. BMP7 induced Noggin expression and activation of Smad1/5/8 can be diminished by 17-β-oestradiol and LDN-193189. Noggin overexpression in MCF-7 cells resulted in an increase of proliferation. Conclusion Noggin expression can be repressed by oestrogen through an inference of the BMP- Smad signalling. Overexpression of Noggin promoted proliferation of MCF-7 cells. Further investigation is required to clarify the exact role of Noggin in ER positive breast cancer and its implication in the disease progression and current therapies. Citation Format: Ming Liu, Lin Ye, Wen G. Jiang. Oestrogen represses Noggin expression by interfering BMP/Smad signalling in ER positive breast cancer cells [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-14-03.

Abstract 3458: Novel anti-NME7antibody inhibits metastasis of solid tumor cancers

Abstract Purpose: To develop an antibody therapeutic that disrupts interaction between onco-embryonic growth factor NME7AB and its cognate growth factor receptor, MUC1*, for the treatment of solid tumors and inhibition of their metastases. Normally, NME7 is only expressed and secreted by cells of a Day 3 to Day 5 human blastocyst. NME7 expression is then turned off and expression of self-regulating, adult forms of NME proteins is turned on. However, we found that NME7 expression is mistakenly turned on again in cancer cells. Cleavage of NME7 to NME7AB enables secretion from the cell, where it then binds to and dimerizes the MUC1* extracellular domain, which activates the MAP kinase signaling cascade. Methods: Because NME7AB shares homology to other adult forms of NME proteins, which are required for normal cellular function, we needed to develop a monoclonal antibody that binds to NME7AB, but not to other NME proteins, and disrupts its interaction with the MUC1* growth factor receptor as well. To investigate the effects of NME7AB on cancer growth and metastasis, we generated populations of cancer cells that had been cultured in a serum-free media to which was added a recombinant NME7AB. The parent cells, the NME7AB grown progeny, or mixed populations were implanted into NSG mice to test the effect of novel anti-NME7AB antibodies on tumor growth and metastasis. Parent tumor cells and the NME7AB-grown cells were engineered to emit light at different wavelengths so that growth of each population could be separately tracked in live animals. Results: Cancer cells that were cultured in a serum-free media containing recombinant NME7AB for 10 days acquired characteristics of more metastatic cells, often called cancer stem cells (referred to here as NME7AB-CSCs). They upregulated metastatic markers by up to 100-fold, became non-adherent, entered dormancy and formed tumors from injection of as few as 10,000 cells. The addition of an anti-NME7AB antibody during the 10-day culture period blocked this transition. NME7AB-CSCs that were injected into the tail vein of NSG mice induced widespread metastasis in 6-10 days, after which an anti-NME7AB antibody was i.v. administered. The anti-NME7AB antibody greatly reduced or cleared the metastasis. Animals implanted sub-cutaneously with NME7AB-CSCs, then administered anti-NME7AB antibody, showed a significant reduction in the spread of breast cancer cells to the liver. Mixed populations of parent cells plus NME7AB-CSCs, which emitted light at different wavelengths, were implanted sub-cutaneously and allowed to become established. The percent of the implanted tumor that was NME7AB-CSCs determined the growth rate of the entire tumor. An anti-NME7AB antibody inhibited growth of the parent cells as well as the NME7AB-CSCs. Conclusion: These data support further pre-clinical development to allow for a clinical candidate to be tested in a metastatic as well as an adjuvant setting. Citation Format: Cynthia Carol Bamdad, Benoit J. Smagghe, Mark G. Carter, Trevor J. Grant, Danica M. Page, Laura M. Reale, Michael J. Nash, Jac-Leen S. Nash, Andrew K. Stewart. Novel anti-NME7antibody inhibits metastasis of solid tumor cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3458.

Cooperative interaction between ER\u03b1 and the EMT-inducer ZEB1 reprograms breast cancer cells for bone metastasis

The epithelial to mesenchymal transition (EMT) has been proposed to contribute to the metastatic spread of breast cancer cells. EMT-promoting transcription factors determine a continuum of different EMT states. In contrast, estrogen receptor α (ERα) helps to maintain the epithelial phenotype of breast cancer cells and its expression is crucial for effective endocrine therapies. Determining whether and how EMT-associated transcription factors such as ZEB1 modulate ERα signaling during early stages of EMT could promote the discovery of therapeutic approaches to suppress metastasis. Here we show that, shortly after induction of EMT and while cells are still epithelial, ZEB1 modulates ERα-mediated transcription induced by estrogen or cAMP signaling in breast cancer cells. Based on these findings and our ex vivo and xenograft results, we suggest that the functional interaction between ZEB1 and ERα may alter the tissue tropism of metastatic breast cancer cells towards bone.

The Influence of VE-Cadherin on Adhesion and Incorporation of Breast Cancer Cells into Vascular Endothelium.

During metastasis, cancer cells that originate from the primary tumor circulate in the bloodstream, extravasate, and form micrometastases at distant locations. Several lines of evidence suggest that specific interactions between cancer cells and endothelial cells, in particular tumor cell adhesion to the endothelium and transendothelial migration, play a crucial role in extravasation. Here we have studied the role of vascular endothelial (VE)-cadherin which is expressed aberrantly by breast cancer cells and might promote such interactions. By comparing different human breast cancer cell lines, we observed that the number of cancer cells that adhered to endothelium correlated with VE-cadherin expression levels. VE-cadherin silencing experiments confirmed that VE-cadherin enhances cancer cell adhesion to endothelial cells. However, in contrast, the number of cancer cells that incorporated into the endothelium was not dependent on VE-cadherin. Thus, it appears that cancer cell adhesion and incorporation are distinct processes that are governed by different molecular mechanisms. When cancer cells incorporated into the endothelial monolayer, they formed VE-cadherin positive contacts with endothelial cells. On the other hand, we also observed tumor cells that had displaced endothelial cells, reflecting either different modes of incorporation, or a temporal sequence where cancer cells first form contact with endothelial cells and then displace them to facilitate transmigration. Taken together, these results show that VE-cadherin promotes the adhesion of breast cancer cells to the endothelium and is involved in the initial phase of incorporation, but not their transmigration. Thus, VE-cadherin might be of relevance for therapeutic strategies aiming at preventing the metastatic spread of breast cancer cells.

Neuronal calcium sensor 1 (NCS1) promotes motility and metastatic spread of breast cancer cells in vitro and in vivo.

Increased levels of the calcium-binding protein neuronal calcium sensor 1 (NCS1) predict an unfavorable patient outcome in several aggressive cancers, including breast and liver tumors. Previous studies suggest that NCS1 overexpression facilitates metastatic spread of these cancers. To investigate this hypothesis, we explored the effects of NCS1 overexpression on cell proliferation, survival, and migration patterns in vitro in 2- and 3-dimensional (2/3-D). Furthermore, we translated our results into an in vivo mouse xenograft model. Cell-based proliferation assays were used to demonstrate the effects of overexpression of NCS1 on growth rates. In vitro colony formation and wound healing experiments were performed and 3-D migration dynamics were studied using collagen gels. Nude mice were injected with breast cancer cells to monitor NCS1-dependent metastasis formation over time. We observed that increased NCS1 levels do not change cellular growth rates, but do significantly increase 2- and 3-D migration dynamics in vitro. Likewise, NCS1-overexpressing cells have an increased capacity to form distant metastases and demonstrate better survival and less necrosis in vivo. We found that NCS1 preferentially localizes to the leading edge of cells and overexpression increases the motility of cancer cells. Furthermore, this phenotype is correlated with an increased number of metastases in a xenograft model. These results lay the foundation for exploring the relevance of an NCS1-mediated pathway as a metastatic biomarker and as a target for pharmacologic interventions.-Apasu, J. E., Schuette, D., LaRanger, R., Steinle, J. A., Nguyen, L. D., Grosshans, H. K., Zhang, M., Cai, W. L., Yan, Q., Robert, M. E., Mak, M., Ehrlich, B. E. Neuronal calcium sensor 1 (NCS1) promotes motility and metastatic spread of breast cancer cells in vitro and in vivo.

Newly characterized motile sperm domain-containing protein 2 promotes human breast cancer metastasis.

Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death among women worldwide. Breast cancer metastasis results in poor prognosis and increased mortality, but the mechanisms of breast cancer metastasis are yet to be fully resolved. Identifying distinctive proteins that regulate metastasis might be targeted to improve therapy in breast cancer. We previously described MOSPD2 as a surface membrane protein that regulates monocyte migration in vitro. In this study, we demonstrate for the first time that MOSPD2 has a major role in breast cancer cell migration and metastasis. MOSPD2 expression was highly elevated in invasive and metastatic breast cancer while it was absent or residual in normal tissue and in primary in situ tumors. In vitro experiments showed that silencing MOSPD2 in different breast cancer cell lines significantly inhibited cancer cell chemotaxis migration. Mechanistically, we found that silencing MOSPD2 profoundly abated phosphorylation events that are involved in breast tumor cell chemotaxis. In vivo, MOSPD2‐silenced breast cancer cells exhibited marked impaired metastasis to the lungs. These results indicate that MOSPD2 plays a key role in the migration and metastasis of breast cancer cells and may be used to prevent the spreading of breast cancer cells and to mediate their death.

Molecular and Transcriptional Signatures for ErbB2-Induced Invasion

Invasion and metastasis are the most fatal activities connected to ErbB2. Current ErbB2-targeting therapies are highly efficient against early stage breast cancer, but often fail to cure the advanced cases. It is estimated that the majority of ErbB2-positive, invasive breast cancers are either intrinsically resistant to the current antibody-based therapy or can develop into resistant disease with high risk of metastasis. Local invasion is a prerequisite for metastatic dissemination. Here, we introduce and summarize the latest mechanistic knowledge of how ErbB2 activation can lead to invasion and spreading of breast cancer cells. In this review, we focus on the recent research in the molecular and cellular changes that initiate and maintain ErbB2-induced invasion. These comprise mechanisms that can promote cell migration and those that activate the extracellular degradome, as well as the involvement of lysosomes. We also discuss epithelial-to-mesenchymal transition and circulating tumor cells and what is currently known about their role in invasive, ErbB2-positive breast cancer. The activation of invasion in ErbB2-positive breast cancer cells is accomplished by initiation of invasion-promoting transcriptional programs, including activation of transcription factors such as myeloid zinc finger 1 (MZF1) and Ets1 that leads to changes in the expression of genes that can drive and maintain the invasive and metastatic cellular phenotype. Increasing our understanding of the downstream components of the ErbB2 signaling, especially those that regulate its invasive function, can contribute to the development of novel treatments that benefit patients with advanced and therapy-resistant ErbB2-positive breast cancer.

Opportunities for Studying the Hydrodynamic Context for Breast Cancer Cell Spread Through Lymph Flow.

The lymphatic system serves as the primary route for the metastatic spread of breast cancer cells (BCCs). A scarcity of information exists with regard to the advection of BCCs in lymph flow and a fundamental understanding of the response of BCCs to the forces in the lymphatics needs to be established. This review summarizes the flow environment metastatic BCCs are exposed to in the lymphatics. Special attention is paid to the behavior of cells/particles in microflows in an attempt to elucidate the behavior of BCCs under lymph flow conditions (Reynolds number <1).

MicroRNA-7 suppresses the homing and migration potential of human endothelial cells to highly metastatic human breast cancer cells

Background:MicroRNA-7 (miR-7) has been observed as a potent tumour suppressor in multiple cancer types including breast cancer. The aim of this study was to investigate the response sensitivities of metastatic breast cancer cells to miR-7 and the roles of miR-7 in the interaction of endothelial cells and metastatic cancer cells.Methods:Expression profile of miRNAs in a breast cancer specimen cohort and breast cancer cells were determined using real-time quantitative miRNA assays. Effect of the altering expression of miR-7 on migration, invasion, proliferation, interaction and underlying molecular mechanism of breast cancer cells and endothelial cells was investigated after treatment with the synthesised mimic of miR-7. Luciferase activity analysis was performed to validate Wave-3 as a novel target of miR-7.Results:miR-7 expression was negatively correlated with the stage, grade and survival of the breast cancer patients. There was also differential expression of miRNAs including miR-7 in the breast cancer cells. The synthesised mimic of miR-7 inhibits the motility and wound healing potential of breast cancer cells. The highly metastatic MDA-MB-231 cells are more sensitive to the miR-7 treatment than the poorly invasive MCF-7 cells. Treatment with miR-7 downregulated the expression of EGFR, IGF1R and Wave3 in MDA-MB-231 cells but not in MCF-7 cells. In addition, we further demonstrated that miR-7 inhibited the proliferation, migration and invasion of endothelial cells. And more importantly, miR-7 suppressed the homing and migration of endothelial cells to more aggressive tumour cell conditions.Conclusions:Given the dual inhibitory effect of miR-7 on metastatic breast cancer cells alone and the interaction of endothelial cells with the tumour-conditioned microenvironment, we suggest miR-7 may be a new therapeutic candidate for its capacity not only to prevent breast cancer cell spreading but also to inhibit tumour-associated angiogenesis in the metastatic breast cancer.

The advection of microparticles, MCF-7 and MDA-MB-231 breast cancer cells in response to very low Reynolds numbers.

The lymphatic system is an extensive vascular network that serves as the primary route for the metastatic spread of breast cancer cells (BCCs). The dynamics by which BCCs travel in the lymphatics to distant sites, and eventually establish metastatic tumors, remain poorly understood. Particle tracking techniques were employed to analyze the behavior of MCF-7 and MDA-MB-231 BCCs which were exposed to lymphatic flow conditions in a 100 μm square microchannel. The behavior of the BCCs was compared to rigid particles of various diameters (η = dp/H= 0.05-0.32) that have been used to simulate cell flow in lymph. Parabolic velocity profiles were recorded for all particle sizes. All particles were found to lag the fluid velocity, the larger the particle the slower its velocity relative to the local flow (5%-15% velocity lag recorded). A distinct difference between the behavior of BCCs and particles was recorded. The BCCs travelled approximately 40% slower than the undisturbed flow, indicating that morphology and size affects their response to lymphatic flow conditions (Re < 1). BCCs adhered together, forming aggregates whose behavior was irregular. At lymphatic flow rates, MCF-7s were distributed uniformly across the channel in comparison to the MDA-MB-231 cells which travelled in the central region (88% of cells found within 0.35 ≤ W ≤ 0.64), indicating that metastatic MDA-MB-231 cells are subjected to a lower range of shear stresses in vivo. This suggests that both size and deformability need to be considered when modelling BCC behavior in the lymphatics. This finding will inform the development of in vitro lymphatic flow and metastasis models.

Human cytomegalovirus interleukin-10 enhances matrigel invasion of MDA-MB-231 breast cancer cells

BackgroundWhile some risk factors for breast cancer are well-known, the influence of other factors, particularly virus infection, remains unclear. Human cytomegalovirus (HCMV) is widespread in the general population, and both molecular and epidemiological evidence has indicated links between HCMV and breast cancer. The HCMV protein cmvIL-10 is a potent suppressor of immune function that has also been shown to promote proliferation and migration of breast cancer cells. In this study, the impact of cmvIL-10 on tumor cell invasion through a simulated basement membrane was investigated.ResultsMDA-MB-231 breast cancer cells exhibited invasion through a matrigel layer that was significantly enhanced in the presence of either purified cmvIL-10 or supernatants from HCMV-infected cells containing secreted cmvIL-10. Transcriptional profiling revealed that cmvIL-10 altered expression of several genes implicated in metastasis. Exposure to cmvIL-10 resulted in higher MMP-3 mRNA levels, greater protein expression, and increased enzymatic activity. Treatment with cmvIL-10 also increased expression of both urokinase plasminogen receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1), which can stimulate MMP-3 activity and have previously been identified as poor prognostic markers in breast cancer patients. Finally, MDA-MB-231 cells treated with cmvIL-10 showed significant downregulation of metastasis suppressor 1 (MTSS1), a scaffolding protein that regulates cytoskeletal rearrangements and is frequently lost in metastatic tumors.ConclusionsHCMV, and in particular the secreted viral cytokine, cmvIL-10, can induce cellular changes that facilitate cell migration and invasion. These findings indicate that HCMV may be associated with promoting the malignant spread of breast cancer cells and suggest that antiviral treatment may be a useful complement to chemotherapy in some patients.

Reproductive hormones in breast cancer bone metastasis: The role of inhibins

The spread of breast cancer cells to bone and survival in this new metastatic environment is influenced not only by the genetic signature of the cells, but also multiple host cells and soluble factors produced locally (paracrine) or from distant sites (endocrine). Disrupting this metastatic process has been evaluated in clinical trials of the bone targeted agents bisphosphonates and denosumab and have shown that these agents reduce the recurrence of breast cancer in postmenopausal women only, suggesting the efficacy of the drugs are influenced by levels of reproductive endocrine hormones. The molecular mechanism driving this differential effect has not been definitively identified, however, there is evidence that both reproductive hormones and bisphosphonates can affect similar paracrine factors and cellular components of the bone metastatic niche. This review focuses on how the ovarian endocrine hormone, inhibin, interacts with the paracrine factors activin and follistatin, abundant in the primary tumour and bone microenvironment, with subsequent effects on tumour cell survival. Inhibin also affects the cellular components of the bone microenvironment primarily the osteoblastic niche. Recent evidence has shown that bisphosphonates also alter this niche, which may represent a common mechanism by which inhibin and bisphosphonates interact to influence disease outcomes in early breast cancer. Further research is needed to fully elucidate these molecular mechanisms to enable understanding and future development of alternative bone targeted treatments with anti-tumour efficacy in premenopausal women.