Previous studies have suggested that breast cancer stem cells (BCSCs) mediate metastasis, are resistant to radiation and chemotherapy, and contribute to relapse. Although several BCSC markers have ...been described, it is unclear whether these markers identify the same or independent BCSCs. Here, we show that BCSCs exist in distinct mesenchymal-like (epithelial-mesenchymal transition EMT) and epithelial-like (mesenchymal-epithelial transition MET) states. Mesenchymal-like BCSCs characterized as CD24−CD44+ are primarily quiescent and localized at the tumor invasive front, whereas epithelial-like BCSCs express aldehyde dehydrogenase (ALDH), are proliferative, and are located more centrally. The gene-expression profiles of mesenchymal-like and epithelial-like BCSCs are remarkably similar across different molecular subtypes of breast cancer, and resemble those of distinct basal and luminal stem cells found in the normal breast. We propose that the plasticity of BCSCs that allows them to transition between EMT- and MET-like states endows these cells with the capacity for tissue invasion, dissemination, and growth at metastatic sites.
•BCSCs exist in EMT and MET states with distinct marker and gene-expression profiles•CSCs from different subtypes of breast cancer express common EMT/MET genes•EMT and MET BCSC profiles resemble normal mammary basal and luminal stem cells•BCSCs display plasticity that enables them to transition between EMT and MET states
Breast cancer stem cells (BCSCs) are thought to mediate metastasis and resistance to radiation and chemotherapy. Here, Liu et al. show that BCSCs exist in distinct mesenchymal-like (CD24−CD44+) and epithelial-like (ALDH+) states with different proliferative and invasive capacities, suggesting it may be clinically important to target alternative CSC states.
Abstract Triple negative breast cancer (TNBC) typically exhibits rapid progression, high mortality and faster relapse rates relative to other breast cancer subtypes. In this report we examine the ...combination of taxanes (paclitaxel or docetaxel) with a breast cancer stem cell (CSC)-targeting agent sulforaphane for use against TNBC. We demonstrate that paclitaxel or docetaxel treatment induces IL-6 secretion and results in expansion of CSCs in TNBC cell lines. Conversely, sulforaphane is capable of preferentially eliminating CSCs, by inhibiting NF-κB p65 subunit translocation, downregulating p52 and consequent downstream transcriptional activity. Sulforaphane also reverses taxane-induced aldehyde dehydrogenase-positive (ALDH+) cell enrichment, and dramatically reduces the size and number of primary and secondary mammospheres formed. In vivo in an advanced treatment orthotopic mouse xenograft model together with extreme limiting dilution analysis (ELDA), the combination of docetaxel and sulforaphane exhibits a greater reduction in primary tumor volume and significantly reduces secondary tumor formation relative to either treatment alone. These results suggest that treatment of TNBCs with cytotoxic chemotherapy would be greatly benefited by the addition of sulforaphane to prevent expansion of and eliminate breast CSCs.
The nonobese diabetic/severe combined immune deficiency (NOD-scid) xenotransplantation model is the “gold standard” for assaying human hematopoietic stem cell activity. Systematic advancements, such ...as depletion of natural killer cell activity with anti-CD122 antibody, direct intrafemoral injection, and deletion or truncation of IL2Rγ, have improved human cell engraftment; however, questions remain whether these mouse models are equivalent or, if not, which model is superior for assaying hematopoietic stem cell activity. To address this, we compared overall engraftment and multilineage differentiation of near-limiting doses of lineage-depleted human umbilical cord blood cells by direct intrafemoral injection into NOD/Lt-scid, NOD/Shi-scid, NOD/Lt-scid/IL2Rγnull (NSG), and NOD/Shi-scid/IL2Rγnull mice. Transplantation into NSG mice generated moderately higher human engraftment levels in bone marrow compared with other strains. At limiting doses, NSG mice of both sexes were 3.6-fold more sensitive in detecting SCID-repopulating cells compared with NOD/Lt-scid mice. However, NSG females exhibited higher engraftment at limiting cell doses, resulting in an overall increase in SCID-repopulating cell detection of 9-fold. Both NSG and NOD/Shi-scid/IL2Rγnull support significantly improved engraftment in peripheral tissues compared with NOD/Lt-scid and NOD/Shi-scid mice, whereas NSG mice provide greater human engraftment in bone marrow than all other strains, especially at limiting doses.
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•The usage of polyphenols inverts the phase of graphene-stabilized emulsions.•Subsequent polymerization of the oil phase yields graphene-coated polymer microspheres or ...capsules.•Contact angle measurements confirmed hydrophilic interaction between tannic acid and graphene.•Variations in graphite amount and flake size tailor the resulting material's properties.•Electrical conductivity dependent on sphere-to-sphere contact and graphite amount.
Polyphenols, specifically tannic acid, should increase the hydrophilicity of graphene when added during the interfacial exfoliation through π-π stacking. Following Bancroft’s rule, increasing the hydrophilicity of graphene will result in a phase inversion of water-in-oil emulsions stabilized by graphene. Polymerization of the oil phase will then lead to graphene-coated spheres rather than graphene-stabilized polyHIPEs.
Optical particle sizing, microscopy, contact angle, and electrical conductivity measurements were performed to determine the mechanism of sphere formation in graphene-stabilized emulsions modified with tannic acid. Studies focused on the effect of graphite flake size, graphite concentration, tannic acid concentration, and oil phase composition. Particle sizing and scanning electron microscopy examined the spheres' size, shape, and surface morphology. Contact angle measurements gave insight into the change in graphene surface energy. Conductivity studies examined the graphene shell surrounding the spheres.
Adding tannic acid to graphene-stabilized emulsions induced a phase change from water-in-oil to oil-in-water. Contact angle measurements confirmed greater hydrophilicity of graphene in the presence of tannic acid. However, very high tannic acid concentrations led to a decrease in the stability of the emulsion. Varying the graphite flake size and concentration resulted in morphology and conductivity changes. Dilution of the monomer phase produced hollow microcapsules.
Although breast cancer stem cells (BCSCs) display plasticity transitioning between quiescent mesenchymal-like (M) and proliferative epithelial-like (E) states, how this plasticity is regulated by ...metabolic or oxidative stress remains poorly understood. Here, we show that M- and E-BCSCs rely on distinct metabolic pathways and display markedly different sensitivities to inhibitors of glycolysis and redox metabolism. Metabolic or oxidative stress generated by 2DG, H2O2, or hypoxia promotes the transition of ROSlo M-BCSCs to a ROShi E-state. This transition is reversed by N-acetylcysteine and mediated by activation of the AMPK-HIF1α axis. Moreover, E-BCSCs exhibit robust NRF2-mediated antioxidant responses, rendering them vulnerable to ROS-induced differentiation and cytotoxicity following suppression of NRF2 or downstream thioredoxin (TXN) and glutathione (GSH) antioxidant pathways. Co-inhibition of glycolysis and TXN and GSH pathways suppresses tumor growth, tumor-initiating potential, and metastasis by eliminating both M- and E-BCSCs. Exploiting metabolic vulnerabilities of distinct BCSC states provides a novel therapeutic approach targeting this critical tumor cell population.
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•E- and M-BCSCs have divergent sensitivities to glycolysis or redox metabolism inhibition•Hypoxic or oxidant stress promotes M to E state transition by activating AMPK-HIF1α•E-BCSCs are more oxidative (OXPHOS) and reliant on NRF2 antioxidant responses•Co-inhibition of glycolysis and TXN and GSH pathways targets both M- and E-BCSCs
Luo et al. report that metabolic stressors modulate breast cancer stem cell (BCSC) state dynamics through ROS-mediated activation of the AMPK-HIF1α axis. They further describe the metabolic pathways and vulnerabilities of epithelial- and mesenchymal-like BCSCs and build a conceptual framework to effectively target both BCSC states in PDX and systemic metastasis models of TNBC.
Targeting breast cancer stem cells McDermott, Sean P.; Wicha, Max S.
Molecular oncology,
October 2010, Volume:
4, Issue:
5
Journal Article
Peer reviewed
Open access
The cancer stem cell (CSC) hypothesis postulates that tumors are maintained by a self-renewing CSC population that is also capable of differentiating into non-self-renewing cell populations that ...constitute the bulk of the tumor. Although, the CSC hypothesis does not directly address the cell of origin of cancer, it is postulated that tissue-resident stem or progenitor cells are the most common targets of transformation. Clinically, CSCs are predicted to mediate tumor recurrence after chemo- and radiation-therapy due to the relative inability of these modalities to effectively target CSCs. If this is the case, then CSC must be efficiently targeted to achieve a true cure. Similarities between normal and malignant stem cells, at the levels of cell-surface proteins, molecular pathways, cell cycle quiescence, and microRNA signaling present challenges in developing CSC-specific therapeutics. Approaches to targeting CSCs include the development of agents targeting known stem cell regulatory pathways as well as unbiased high-throughput siRNA or small molecule screening. Based on studies of pathways present in normal stem cells, recent work has identified potential “Achilles heals” of CSC, whereas unbiased screening provides opportunities to identify new pathways utilized by CSC as well as develop potential therapeutic agents. Here, we review both approaches and their potential to effectively target breast CSC.
MicroRNAs (miRNAs) play important roles in normal cellular differentiation and oncogenesis. microRNA93 (mir-93), a member of the mir106b-25 cluster, located in intron 13 of the MCM7 gene, although ...frequently overexpressed in human malignancies may also function as a tumor suppressor gene. Using a series of breast cancer cell lines representing different stages of differentiation and mouse xenograft models, we demonstrate that mir-93 modulates the fate of breast cancer stem cells (BCSCs) by regulating their proliferation and differentiation states. In "claudin(low)" SUM159 cells, expression of mir-93 induces Mesenchymal-Epithelial Transition (MET) associated with downregulation of TGFβ signaling and downregulates multiple stem cell regulatory genes, including JAK1, STAT3, AKT3, SOX4, EZH1, and HMGA2, resulting in cancer stem cell (CSC) depletion. Enforced expression of mir-93 completely blocks tumor development in mammary fat pads and development of metastases following intracardiac injection in mouse xenografts. The effect of mir-93 on the CSC population is dependent on the cellular differentiation state, with mir-93 expression increasing the CSC population in MCF7 cells that display a more differentiated "luminal" phenotype. mir-93 also regulates the proliferation and differentiation of normal breast stem cells isolated from reduction mammoplasties. These studies demonstrate that miRNAs can regulate the states and fates of normal and malignant mammary stem cells, findings which have important biological and clinical implications.
Abstract The transfer of DNA from hands to objects by holding or touching has been examined in the past. The main purpose of this study was to examine the variation in the amount of DNA transferred ...from hands to glass, fabric and wood. The study involved 300 volunteers (100 for glass, 100 for fabric and 100 for wood) 50% of which were male and 50% female. The volunteers held the material for 60 s. The DNA was recovered from the objects using a minitape lift, quantified using the Quantifiler kit assay, extracted using a ‘Qiagen® QIAamp DNA mini kit’ and amplified using the AmpF l STR® SGM Plus™ Amplification Kit at 28 cycles. The results show that using ANOVA there was a significant difference ( F = 8.2, p < 0.05) between the three object types in the amount of DNA recovered. In terms of DNA transfer and recovery, wood gave the best yield, followed by fabric and then glass. The likelihood of success of obtaining a profile indicative of the holder was approximately 9% for glass samples, 23% for fabric and 36% for wood. There was no significant difference between the amount of DNA transferred by male or female volunteers. In this study good shedder status, as defined by obtaining useful profiles of 6 or more alleles, is estimated at approximately 22% of the population. The phenomenon of secondary transfer was observed when mixed DNA profiles were obtained but the incidence was low at approximately 10% of the total number of samples. DNA profiles corresponding to more than one person were found on objects which had been touched by only one volunteer. Although secondary transfer is possible the profiles obtained from touched objects are more likely to be as a result of primary transfer rather than a secondary source.
Sinusitis is a common pediatric illness that can be complicated by periorbital or intracranial extension. Patients can be managed with antimicrobials alone or in conjunction with surgical ...intervention. This article examines management patterns and outcomes in pediatric patients presenting with complicated sinusitis.
Case series with chart review.
Tertiary care pediatric hospital.
An evaluation of 168 pediatric patients with complicated sinusitis with periorbital complications presenting at a single institution from 2008 to 2018 was performed. Demographics, disease characteristics, in-hospital management, and outcomes were recorded and analyzed.
The most common complication was orbital cellulitis, seen in 49% of children. Surgical intervention occurred in 49% of patients, with 36% receiving medical therapy followed by surgery (MTS). Chandler I patients underwent surgical intervention 30% of the time, Chandler II patients 29%, and Chandler III patients 83%. Nineteen percent of initially nonoperative patients started on ampicillin-sulbactam required MTS vs 57% of those started on other antibiotic regimens (
= .01). Twelve percent of initially nonoperative Chandler I to II patients started on ampicillin-sulbactam needed MTS vs 40% started on other antibiotic regimens. Hospital charges for operative patients were $45,056 vs $14,311 for nonoperative patients (
< .01). Hospital charges for patients with surgery followed by medical therapy (SMT) were $45,563 vs $44,393 for MTS (
= .92).
Nonoperative early stage patients started on ampicillin-sulbactam had a lower risk of MTS. MTS did not cost significantly more than SMT, and there were no significant outcome differences seen.
Considerable evidence suggests that many malignancies are driven by a cellular compartment that displays stem cell properties. Cancer stem-like cells (CSCs) can be identified by expression of cell ...surface markers or enzymatic activity, but these methods are limited by phenotypic heterogeneity and plasticity of CSCs. An alternative phenotypic methodology based on in-vitro sphere formation has been developed, but it is typically labor-intensive and low-throughput. In this work, we present a 1,024-microchamber microfluidic platform for single-cell derived sphere formation. Utilizing a hydrodynamic capturing scheme, more than 70% of the microchambers capture only one cell, allowing for monitoring of sphere formation from heterogeneous cancer cell populations for identification of CSCs. Single-cell derived spheres can be retrieved and dissociated for single-cell analysis using a custom 96-gene panel to probe heterogeneity within the clonal CSC spheres. This microfluidic platform provides reliable and high-throughput sphere formation for CSC identification and downstream clonal analysis.
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