Signaling through the nicotinic acetylcholine receptor in the liver protects against the development of metabolic dysfunction-associated steatohepatitis.

Metabolic dysfunction-associated steatohepatitis (MASH) is the progressive form of liver steatosis, the most common liver disease, and substantially increases the mortality rate. However, limited therapies are currently available to prevent MASH development. Identifying potential pharmacological treatments for the condition has been hampered by its heterogeneous and complex nature. Here, we identified a hepatic nonneuronal cholinergic signaling pathway required for metabolic adaptation to caloric overload. We found that cholinergic receptor nicotinic alpha 2 subunit (CHRNA2) is highly expressed in hepatocytes of mice and humans. Further, CHRNA2 is activated by a subpopulation of local acetylcholine-producing macrophages during MASH development. The activation of CHRNA2 coordinates defensive programs against a broad spectrum of MASH-related pathogenesis, including steatosis, inflammation, and fibrosis. Hepatocyte-specific loss of CHRNA2 signaling accelerates the disease onset in different MASH mouse models. Activation of this pathway via pharmacological inhibition of acetylcholine degradation protects against MASH development. Our study uncovers a hepatic nicotinic cholinergic receptor pathway that constitutes a cell-autonomous self-defense route against prolonged metabolic stress and holds therapeutic potential for combatting human MASH.

Bone quality assessment in patients with healing mandibular fracture sites: a computed tomography investigation.

The objective of this retrospective study was to assess the bone quality of healing mandibular fracture sites by measuring the Hounsfield units (HU) on computed tomographic (CT) images obtained presurgery and postsurgery in patients treated with rigid internal fixation (RIF). The HU values of healing fracture sites were compared to those of corresponding nonfractured (control) sites on the opposing side and cervical vertebrae sites in the same patients. In total, 31 patients with 45 mandibular fractures treated with RIF underwent presurgical and postsurgical CT examinations. The scans performed after surgery (1, 3, 6, 12, or 18 months) were taken only when there was a need for radiographic evaluation due to a complaint of discomfort from the patient or when the surgeon needed to verify the postsurgical outcome, and each patient underwent only a single postsurgical CT. At the presurgical CT examination, the HU values were lower in the fracture sites than in the control sites. At 3 months postsurgery, the HU values in the fracture sites had increased as the mandibular bone healed. At 6 months postsurgery, the HU values in the fracture sites were higher than those of the control sites. At 12 and 18 months postsurgery, the HU values of both sites were similar. The HU values of the cervical vertebrae remained constant with time. These results suggest that, in patients who have been treated with RIF for mandibular bone fracture, HU values measured by CT vary across time, expressing the physiologic bone healing process.

"We Don't Want to Screen for the Sake of Screening": A Qualitative Evaluation of a Social Needs Screening and Referral Intervention in the NICU.

BACKGROUND: Low uptake of social determinants of health (SDH) screening and referral interventions within neonatal intensive care units (NICUs) is partly due to limited understanding of the best procedures to integrate this practice into routine clinical workflows. PURPOSE: To examine the feasibility and acceptability of an SDH screening and referral intervention in the NICU from the perspective of neonatal nurses; and to identify factors affecting implementation outcomes. METHODS: We conducted 25 semistructured interviews with NICU nurses. We used the Promoting Action on Research Implementation in Health Services (PARiHS) framework to guide interview questions and codebook development for directed content analysis. Themes were mapped onto the 3 PARiHS domains of context, evidence, and facilitation. FINDINGS: Analysis yielded 8 themes. Context: Nurses felt that stressors experienced by NICU families are magnified in a safety net environment. Nurses shared varying viewpoints of the roles and responsibilities for social care in the NICU, and feared that scarcity of community resources would make it difficult to address families' needs. Evidence: The intervention was perceived to increase identification of adverse SDH and provision of resources; and to potentially jump-start better caregiver and infant health trajectories. Facilitation: Procedures that improved acceptability included dynamic training and champion support, regular feedback on intervention outcomes, and strategies to reduce stigma and bias. CONCLUSION: We identified contextual factors, concrete messaging, and training procedures that may inform implementation of SDH screening and referral in NICU settings.

Bayesian paired comparison with the bpcs package.

This article introduces the bpcs R package (Bayesian Paired Comparison in Stan) and the statistical models implemented in the package. This package aims to facilitate the use of Bayesian models for paired comparison data in behavioral research. Bayesian analysis of paired comparison data allows parameter estimation even in conditions where the maximum likelihood does not exist, allows easy extension of paired comparison models, provides straightforward interpretation of the results with credible intervals, has better control of type I error, has more robust evidence towards the null hypothesis, allows propagation of uncertainties, includes prior information, and performs well when handling models with many parameters and latent variables. The bpcs package provides a consistent interface for R users and several functions to evaluate the posterior distribution of all parameters to estimate the posterior distribution of any contest between items and to obtain the posterior distribution of the ranks. Three reanalyses of recent studies that used the frequentist Bradley-Terry model are presented. These reanalyses are conducted with the Bayesian models of the bpcs package, and all the code used to fit the models, generate the figures, and the tables are available in the online appendix.

Exosomes as a Drug Delivery System in Cancer Therapy: Potential and Challenges.

Exosomes play a pivotal role in mediating intercellular communications and package delivery. They have recently been discovered to serve as diagnostic biomarkers as well as a possible drug delivery vehicle based on their nanometer size range and capability to transfer biological materials to recipient cells. Their unique biocompatibility, high stability, preferred tumor homing, and adjustable targeting efficiency can make exosomes an attractive and potentially effective tool of drug delivery in cancer therapy. While exosomes possess properties that make them uniquely suitable for delivery of bioactive molecules, there remains a to-be-filled gap between the current understanding about exosome biology and the ideal application scenarios. In this review, we summarize the characteristics enabling the potential of exosomes for drug delivery as well as the outstanding questions related to exosome composition and function, production and purification, bioengineering and targeting, uptake and biodistribution, efficacy and immune regulation, etc. Advanced technologies are demanded to visualize, characterize, and sort heterogeneous exosome populations. We are positive that the deeper and more comprehensive understanding of exosome biology as well as advanced nanotechnology will certainly accelerate its therapeutic applications.

Bromodomain and Extraterminal Protein Inhibition Blocks Growth of Triple-negative Breast Cancers through the Suppression of Aurora Kinases.

Bromodomain and extraterminal (BET) proteins are epigenetic "readers" that recognize acetylated histones and mark areas of the genome for transcription. BRD4, a BET family member protein, has been implicated in a number of types of cancer, and BET protein inhibitors (BETi) are efficacious in many preclinical cancer models. However, the drivers of response to BETi vary depending on tumor type, and little is known regarding the target genes conveying BETi activity in triple-negative breast cancer (TNBC). Here, we show that BETi repress growth of multiple in vitro and in vivo models of TNBC by inducing two terminal responses: apoptosis and senescence. Unlike in other cancers, response to BETi in TNBC is not dependent upon suppression of MYC Instead, both end points are preceded by the appearance of polyploid cells caused by the suppression of Aurora kinases A and B (AURKA/B), which are critical mediators of mitosis. In addition, AURKA/B inhibitors phenocopy the effects of BETi. These results indicate that Aurora kinases play an important role in the growth suppressive activity of BETi in TNBC. Elucidating the mechanism of response to BETi in TNBC should 1) facilitate the prediction of how distinct TNBC tumors will respond to BETi and 2) inform the rational design of drug combination therapies.

Dependence of carbon nanotubes dispersion kinetics on surfactants.

Carbon nanotubes (CNTs) have been the subject of many studies due to their unique structure and desirable properties. However, the ability to solubilize and separate single CNTs from the bundles they form is still a challenge that needs to be overcome in order to extend their applications in the field of Nanotechnology. Covalent interactions are designed to modify CNTs surface and so prevent agglomeration. Though, this method alters the structures and intrinsic properties of CNTs. In the present work, noncovalent approaches to functionalize and solubilize CNTs are studied in detail. A dispersion kinetic study was performed to characterize the ability of different type of surfactants (non-ionic, anionic, cationic and biopolymer) to unzip CNT bundles. The dispersion kinetic study performed depicts the distinct CNTs bundles unzipping behavior of the different type of surfactants and the results elucidate specific wavelengths in relation with the degree of CNT clustering, which provides new tools for a deeper understanding and characterization of CNTs. Small angle x-ray scattering and transmission electron microscopy results are in agreement with UV-vis-NIR observations, revealing perfectly monodispersed CNTs for the biopolymer and cationic surfactant.

Beyond income: material hardship and the health and healthcare of premature children.

OBJECTIVES: To estimate national prevalence of household hardships (food insufficiency, financial hardship, and difficulty paying medical bills) among children born term and preterm; and examine associations of household hardships with preterm children's outcomes (health status, emergency room visits, and unmet healthcare needs). METHODS: We studied 24,026 children aged 0-3 years born term, preterm with moderately low birth weight (1501-2499 grams) and preterm with very low birth weight (VLBW; ≤1500 grams). Using propensity score matching to control for correlates of poverty, we examined associations of hardships and child outcomes. RESULTS: Compared with term, households with preterm VLBW children had >2-fold higher odds of financial hardship (aOR:2.63; 95% CI: 1.26-5.46) and >5-fold higher odds of difficulty paying bills (aOR:5.60; 95% CI: 2.35-10.35). Matching for sociodemographics, special healthcare needs, income and receipt of public benefits, hardships were independently associated with adverse preterm children's outcomes. CONCLUSIONS: Addressing household hardships is needed to optimize preterm child outcomes.

Association of Primary Language with Provision of Mother's Milk Among Very-Low-Birthweight Infants in Massachusetts.

Background: Racial/ethnic inequities in mother's milk provision for hospitalized preterm infants persist. The extent to which primary language contributes to these racial/ethnic inequities is unknown. Objective: Examine associations of maternal race/ethnicity and primary language with (1) any/exclusive mother's milk at hospital discharge and (2) the time to cessation of mother's milk provision during the hospitalization. Methods: We examined 652 mother/very-low-birthweight (VLBW) infant dyads at 9 level 3 neonatal intensive care units in Massachusetts from January 2017 to December 2018. We abstracted maternal race/ethnicity and language from medical records, and examined English and non-English-speaking non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic mothers of any race. We examined associations of race/ethnicity and language with (1) any/exclusive mother's milk at discharge (yes/no) using mixed-effects logistic regression and (2) cessation of mother's milk during the hospitalization using cox proportional hazard models, adjusting for gestational age, birthweight, and accounting for clustering by plurality and hospital. Results: Fifty-three percent were English-speaking NHW, 22% English-speaking NHB, 4% non-English-speaking NHB, 14% English-speaking Hispanic, and 7% non-English-speaking Hispanic. Compared with English-speaking NHW, NHB mothers (English adjusted odds ratio [aOR] 0.28 [0.17, 0.44]; and non-English-speaking aOR 0.55 [0.19, 0.98]), and non-English-speaking Hispanic mothers (aOR 0.29 [0.21, 0.87]) had lower odds of any mother's milk at discharge. In time-to-event analyses, non-English-speaking Hispanic (adjusted hazard ratio [aHR] 4.37 [2.20, 6.02]) and English-speaking NHB mothers (aHR 3.91 [1.41, 7.61] had the earliest cessation of mother's milk provision. Conclusion: In Massachusetts, maternal primary language was associated with inequities in mother's milk provision for VLBW infants with a differential effect for NHB and Hispanic mothers.

Computational ranking-assisted identification of Plexin-B2 in homotypic and heterotypic clustering of circulating tumor cells in breast cancer metastasis.

Metastasis is the cause of over 90% of all deaths associated with breast cancer, yet the strategies to predict cancer spreading based on primary tumor profiles and therefore prevent metastasis are egregiously limited. As rare precursor cells to metastasis, circulating tumor cells (CTCs) in multicellular clusters in the blood are 20-50 times more likely to produce viable metastasis than single CTCs. However, the molecular mechanisms underlying various CTC clusters, such as homotypic tumor cell clusters and heterotypic tumor-immune cell clusters, are yet to be fully elucidated. Combining machine learning-assisted computational ranking with experimental demonstration to assess cell adhesion candidates, we identified a transmembrane protein Plexin- B2 (PB2) as a new therapeutic target that drives the formation of both homotypic and heterotypic CTC clusters. High PB2 expression in human primary tumors predicts an unfavorable distant metastasis-free survival and is enriched in CTC clusters compared to single CTCs in advanced breast cancers. Loss of PB2 reduces formation of homotypic tumor cell clusters as well as heterotypic tumor-myeloid cell clusters in triple-negative breast cancer. Interactions between PB2 and its ligand Sema4C on tumor cells promote homotypic cluster formation, and PB2 binding with Sema4A on myeloid cells (monocytes) drives heterotypic CTC cluster formation, suggesting that metastasizing tumor cells hijack the PB2/Sema family axis to promote lung metastasis in breast cancer. Additionally, using a global proteomic analysis, we identified novel downstream effectors of the PB2 pathway associated with cancer stemness, cell cycling, and tumor cell clustering in breast cancer. Thus, PB2 is a novel therapeutic target for preventing new metastasis.

Patient Perspectives of the Hospital Discharge Process: A Qualitative Study.

Care transitions after hospitalization require communication across care teams, patients, and caregivers. As part of a quality improvement initiative, we conducted qualitative interviews with a diverse group of 53 patients who were recently discharged from a hospitalization within a safety net hospital to explore how patient preferences were included in the hospital discharge process and differences in the hospital discharge experience by race/ethnicity. Four themes emerged from participants regarding desired characteristics of interactions with the discharge team: (1) to feel heard, (2) inclusion in decision-making, (3) to be adequately prepared to care for themselves at home through bedside teaching, (4) and to have a clear and updated discharge timeline. Additionally, participants identified patient-level factors the discharge planning team should consider, including the social context, family involvement, health literacy, and linguistic barriers. Lastly, participants identified provider characteristics, such as a caring and empathetic bedside manner, that they found valuable in the discharge process. Our findings highlight the need for shared decision-making in the discharge planning process to improve both patient safety and satisfaction.

Implementing Social Risk Screening and Referral to Resources in the NICU.

OBJECTIVE: Social risk screening is recommended by the American Academy of Pediatrics, but this practice is underutilized in NICUs. To address this gap in social care, we aimed to increase rates of: (1) systematic social risk screening and (2) connection with community resources, each to ≥50% over a 14-month period. METHODS: We conducted a quality improvement initiative from November 2020 to January 2022. We adapted a screening tool and used Plan-Do-Study-Act cycles to integrate screening and referral to resources into clinical workflow. Primary outcome measures included the percentage of (1) families screened and (2) connection with resources. We examined screening by maternal race/ethnicity and primary language. Process measures were (1) time from admission to screening and (2) percentage of referrals provided to families reporting unmet needs and requesting assistance. We used statistical process control to assess change over time and χ2 tests to compare screening by race/ethnicity and language. RESULTS: The rates of systematic screening increased from 0% to 49%. Among 103 families screened, 84% had ≥1, and 64% had ≥2 unmet needs, with a total of 221 needs reported. Education, employment, transportation, and food were the most common needs. Screening rates did not vary by race/ethnicity or language. Among families requesting assistance, 98% received referrals. The iterative improvement of a written resource guide and community partnerships led to increased rates of connection with resources from 21% to 52%. CONCLUSION: Leveraging existing staff, our social risk screening and referral intervention built the capacity to address the high burden of unmet needs among NICU families.

Dynamic Glycoprotein Hyposialylation Promotes Chemotherapy Evasion and Metastatic Seeding of Quiescent Circulating Tumor Cell Clusters in Breast Cancer.

Most circulating tumor cells (CTC) are detected as single cells, whereas a small proportion of CTCs in multicellular clusters with stemness properties possess 20- to 100-times higher metastatic propensity than the single cells. Here we report that CTC dynamics in both singles and clusters in response to therapies predict overall survival for breast cancer. Chemotherapy-evasive CTC clusters are relatively quiescent with a specific loss of ST6GAL1-catalyzed α2,6-sialylation in glycoproteins. Dynamic hyposialylation in CTCs or deficiency of ST6GAL1 promotes cluster formation for metastatic seeding and enables cellular quiescence to evade paclitaxel treatment in breast cancer. Glycoproteomic analysis reveals newly identified protein substrates of ST6GAL1, such as adhesion or stemness markers PODXL, ICAM1, ECE1, ALCAM1, CD97, and CD44, contributing to CTC clustering (aggregation) and metastatic seeding. As a proof of concept, neutralizing antibodies against one newly identified contributor, PODXL, inhibit CTC cluster formation and lung metastasis associated with paclitaxel treatment for triple-negative breast cancer. SIGNIFICANCE: This study discovers that dynamic loss of terminal sialylation in glycoproteins of CTC clusters contributes to the fate of cellular dormancy, advantageous evasion to chemotherapy, and enhanced metastatic seeding. It identifies PODXL as a glycoprotein substrate of ST6GAL1 and a candidate target to counter chemoevasion-associated metastasis of quiescent tumor cells. This article is featured in Selected Articles from This Issue, p. 1949.

Structure of the Solid-State Electrolyte Li3+2xP1-xAlxS4: Lithium-Ion Transport Properties in Crystalline vs Glassy Phases.

The search for new solid electrolyte materials and an understanding of fast-ion conductivity are crucial for the development of safe and high-power all-solid-state battery technology. Herein, we present the synthesis, structure, and properties of a crystalline lithium-ion conductor, Li3.3Al0.15P0.85S4 (i.e., Li9.9Al0.45P2.55S12), found in the compositional range Li3+2xP1-xAlxS4 (x = 0.15, 0.20, and 0.33). 31P magic-angle spinning nuclear magnetic resonance (MAS-NMR) aided in identifying the successful introduction of Al into the lattice. At high values of x (>0.15), crystalline Li5AlS4 and a glassy amorphous component exsolve to yield a multiphase mixture. The crystal structure of Li3.3Al0.15P0.85S4 was elucidated by single-crystal X-ray diffraction and powder neutron diffraction, demonstrating that it belongs to the thio-LISICON family with the Pnma space group, a = 12.9572(13) Å, b = 8.0861(8) Å, c = 6.1466(6) Å, and V = 644.00(11) Å3. The Li+-ion conductivity and diffusivity in this bulk material (which contains about 10 wt % of an amorphous phase, as prepared) were studied by electrochemical impedance spectroscopy and 7Li pulsed-field gradient nuclear magnetic resonance spectroscopy (PFG-NMR). The total ionic conductivity of Li3.3Al0.15P0.85S4 is 0.22(2) mS·cm-1 at room temperature with an activation energy of 0.30(1) eV. A two-component analysis method based on the Kärger equations was developed to analyze the diffusive exchange between the bulk and amorphous phases of Li3.3Al0.15P0.85S4 detected via the PFG-NMR signal attenuation curves. This approach was employed to quantitatively compare different sample morphologies (glass powder, crystalline powder, and crystalline pellets of Li3.3Al0.15P0.85S4) and assess the influence of the macroscopic state on microscopic ion transport, as supported by NMR relaxation measurements.

Linguistic Disparities in Child Health and Presence of a Medical Home Among United States Latino Children.

OBJECTIVE: The impact of household language on Latino-White and Latino intragroup disparities in child health and having a medical home in the United States is poorly understood. This study aimed to examine these disparities 1) between Whites and Latinos (overall and stratified by English-primary-language [EPL] and non-English-primary-language [NEPL] households); 2) within Latinos, stratified by household language; and 3) potential moderation of disparities by social determinants. METHODS: Cross-sectional analysis of nationally representative sample of children 0 to 17 years old from the 2016-2018 National Survey of Children's Health. We evaluated associations of child race/ethnicity and household language with child health and presence of a medical home. Multivariable logistic regression was used to compare groups of interest, adjusting for sociodemographic factors and health needs. Moderation was assessed using interaction terms for household income, parental educational attainment, and child insurance coverage. RESULTS: Among 81,514 children, 13.5% were NEPL Latino, and 19.4% were EPL Latino. Compared with EPL Whites, both EPL and NEPL Latinos had reduced odds of excellent/very good health (adjusted odds ratio [aOR]: 0.70; 95% confidence interval [CI]: 0.58-0.84; and aOR: 0.42; 95% CI: 0.33-0.53) and presence of a medical home (aOR: 0.62; 95% CI: 0.56-0.69; and aOR: 0.45; 95% CI: 0.37-0.54), respectively. Among Latinos, NEPL (vs EPL) was also associated with reduced odds of excellent/very good health (aOR: 0.61; 95% CI: 0.46-0.83), and presence of a medical home (aOR: 0.66; 95% CI: 0.48-0.78); these associations were magnified by adverse social determinants. CONCLUSIONS: Striking Latino-White and within-Latino medical-home disparities persist in the United States, particularly for NEPL Latino children. Interventions should target social determinants and the rich sociocultural and linguistic diversity of the Latino population.

National Prevalence of Social Determinants of Health Screening Among US Neonatal Care Units.

OBJECTIVES: The extent that universal social determinants of health (SDH) screening in clinical encounters, as recommended by the American Academy of Pediatrics, has been implemented in inpatient pediatric settings is unknown. We aimed to determine the national prevalence and predictors of standardized SDH screening in US level 2 to 4 neonatal care units (NICUs), describe characteristics of SDH screening programs, and ascertain beliefs of clinical leaders about this practice in the NICU setting. METHODS: We randomly selected 100 hospitals with level 2 to 4 NICUs among each of 5 US regions (n = 500) and surveyed clinical leaders from January to November 2021 regarding standardized SDH screening. Responses were weighted for number of level 2 to 4 NICUs in each region and nonresponse. RESULTS: Overall response rate was 34% (28%-40% by region). Twenty-three percent of US level 2 to 4 NICUs reported standardized SDH screening. We found no associations of hospital characteristics, such as region, size, or safety-net status, with implementation of this practice. Existing programs conducted systematic screening early in the hospitalization (84%), primarily led by social workers (92%). We identified practice variation regarding the type of screening tool, but there was substantial overlap among domains incorporated in the screening. Reported barriers to implementation included perceived lack of resources, inadequate referrals, and lack of an inpatient screening tool. CONCLUSIONS: The prolonged neonatal hospitalization provides opportunities to systematically address SDH. Yet, only 23% of US level 2 to 4 NICUs have implemented this practice. To scale-up implementation, quality improvement may support adaptation of screening and referral processes to the NICU context.

Maternal language disparities in neonatal intensive care unit outcomes.

OBJECTIVE: To examine associations of maternal primary language with neonatal intensive care unit (NICU) outcomes (mother's milk at discharge, necrotizing enterocolitis [NEC], late-onset sepsis, weight gain) DESIGN: We performed a retrospective cohort study of mother-infant dyads (<34 weeks' gestation) in 9 NICUs (1/2016-12/2019), examining associations of maternal language (English [ref], Spanish, Other) with NICU outcomes, adjusting for birth weight for gestational age z-score, race/ethnicity, maternal age, and clustering by hospital. RESULTS: Among 1402 mothers, 85% spoke English, 7% spoke Spanish, and 7% spoke another language. Compared to English, infants with Spanish-speaking mothers had slower growth (-0.34 z-score units [-0.58, -0.10]). Infants with other non-English-speaking mothers had increased mother's milk at discharge (aOR 1.48 [1.18, 1.85]), NEC (aOR 1.43 [1.05, 1.95]), late-onset sepsis (aOR 2.84) [1.67, 4.83] and slower growth (-0.17 z-score units [-0.29, -0.05]). CONCLUSIONS: After adjustments, preterm infants with non-English-speaking mothers had worse outcomes than infants with English-speaking mothers.

Machine learning-assisted elucidation of CD81-CD44 interactions in promoting cancer stemness and extracellular vesicle integrity.

Tumor-initiating cells with reprogramming plasticity or stem-progenitor cell properties (stemness) are thought to be essential for cancer development and metastatic regeneration in many cancers; however, elucidation of the underlying molecular network and pathways remains demanding. Combining machine learning and experimental investigation, here we report CD81, a tetraspanin transmembrane protein known to be enriched in extracellular vesicles (EVs), as a newly identified driver of breast cancer stemness and metastasis. Using protein structure modeling and interface prediction-guided mutagenesis, we demonstrate that membrane CD81 interacts with CD44 through their extracellular regions in promoting tumor cell cluster formation and lung metastasis of triple negative breast cancer (TNBC) in human and mouse models. In-depth global and phosphoproteomic analyses of tumor cells deficient with CD81 or CD44 unveils endocytosis-related pathway alterations, leading to further identification of a quality-keeping role of CD44 and CD81 in EV secretion as well as in EV-associated stemness-promoting function. CD81 is coexpressed along with CD44 in human circulating tumor cells (CTCs) and enriched in clustered CTCs that promote cancer stemness and metastasis, supporting the clinical significance of CD81 in association with patient outcomes. Our study highlights machine learning as a powerful tool in facilitating the molecular understanding of new molecular targets in regulating stemness and metastasis of TNBC.

EGFR inhibition blocks cancer stem cell clustering and lung metastasis of triple negative breast cancer.

Triple-negative breast cancer (TNBC) is one of the most aggressive and metastatic breast cancer subtypes lacking targeted therapy. Our recent work demonstrated that circulating tumor cell (CTC) clusters and polyclonal metastasis of TNBC are driven by aggregation of CD44+ cancer stem cells (CSC) and associated with an unfavorable prognosis, such as low overall survival. However, there is no existing therapeutic that can specifically block CTC or CSC cluster formation. Methods: Using patient-derived xenograft (PDX) models, we established an ex vivo tumor cell clustering assay for a pilot screening of blockade antibodies. After identifying EGFR as a target candidate, we modulated the gene expression and inhibited its kinase activity to determine its functional importance in tumor cell clustering and therapeutic inhibition of lung metastasis. We also examined the molecular regulation network of EGFR and a potential connection to CSC marker CD44 and microRNAs, which regulate CTC clustering. Results: We report here that EGFR inhibition successfully blocks circulating CSC (cCSC) clustering and lung metastasis of TNBC. EGFR enhances CD44-mediated tumor cell aggregation and CD44 stabilizes EGFR. Importantly, blocking EGFR by a novel anti-EGFR monoclonal antibody (clone LA1) effectively blocked cell aggregation in vitro and reduced lung metastasis in vivo. Furthermore, our data demonstrated that the tumor suppressor microRNA-30c serves as another negative regulator of cCSC clustering and lung metastasis by targeting CD44 as well as its downstream effector EGFR. Conclusion: Our studies identify a novel anti-EGFR therapeutic strategy to inhibit cCSC aggregation and therefore abolish cCSC cluster-mediated metastasis of TNBC.