Mothering from the Inside Out: Results of a community-based randomized efficacy trial testing a mentalization-based parenting intervention for mothers with addictions.

Mothering from the Inside Out (MIO) is a mentalization-based parenting intervention developed to address challenges common among mothers experiencing substance use disorders (SUDs) and previously deemed effective when delivered by research clinicians. This randomized clinical trial was designed to test the efficacy of MIO when delivered by community-based addiction counselors in Connecticut, USA. Ninety-four mothers [M(SD)age = 31.01(4.01) years; 75.53% White] caring for a child 11-60 months of age were randomly assigned to participate in 12 sessions of either MIO or psychoeducation. Caregiving, psychiatric, and substance use outcomes were assessed repeatedly from baseline through 12-week follow-up. Mothers who participated in MIO showed decreased certainty about their child's mental states, and decreased depression; their children demonstrated increased clarity of cues. Participation in MIO was not associated with the same degree of improvement that was observed in prior trials where MIO was delivered by research clinicians. However, when delivered by community-based clinicians, MIO may be protective against a deterioration in caregiving over time often seen in mothers with addictions. The drop in efficacy of MIO in this trial raises questions about intervention-intervenor fit. Research should examine factors influencing MIO effectiveness to close the science-to-service gap common in the dissemination of empirically validated interventions.

Cuidados Maternales desde Dentro (MIO) es una intervención de crianza con base en la mentalización desarrollada para discutir los retos que son comunes entre las madres que experimentan trastornos de uso de sustancias (SUD) y que previamente eran considerados eficaces cuando los ofrecían los investigadores clínicos. Este ensayo clínico al azar se diseñó para examinar la efectividad de MIO cuando la ofrecen consejeros en asuntos de adicción con base en la comunidad, en Connecticut, Estados Unidos. Noventa y cuatro madres [M(SD) edad = 31.01(4.01) años; 75.53% blancas] con un niño de 11 a 60 meses de edad bajo su cuidado fueron asignadas al azar para participar en 12 sesiones, ya sea de MIO o de psicoeducación. Los resultados del cuidado prestado, los siquiátricos y los de uso de sustancia se evaluaron repetidamente a partir de los datos básicos hasta el seguimiento a las 12 semanas. Las madres que participaron en MIO mostraron una disminución en la certeza acerca de los estados mentales de sus niños, y una disminución en la depresión; sus niños demostraron un aumento en la claridad de las señales. La participación en MIO no se asoció con el mismo grado de mejoramiento que se observó en ensayos previos en los que MIO fue ofrecido por investigadores clínicos. Sin embargo, cuando es ofrecido por clínicos con base comunitaria, MIO pudiera servir de protección contra el deterioro de la prestación de cuidado a lo largo del tiempo, a menudo visto en madres con adicciones. La disminución de la efectividad de MIO en este ensayo genera preguntas acerca de cuán compenetrados está el interventor con la intervención. La investigación debe examinar factores que influyan en la efectividad de MIO para cerrar el vacío entre servicio y ciencia, común en la diseminación de las intervenciones empíricamente validadas.

Le maternage de l'intérieur (abrégé ici MIO pour reprendre l'anglais Mothering from the Inside Out) est une intervention de parentage basée sur la mentalisation, développée afin de répondre aux défis courants chez les mères ayant un trouble lié à l'usage d'une substance (TUS) et préalablement considérée comme efficace lorsque faite par des chercheurs cliniques. Cette étude clinique randomisée a été conçue pour tester l'efficacité du MIO lorsque offert par des intervenants en dépendance communautaires dans l'état du Connecticut aux Etats-Unis. Quatre-vingt-dix-neuf mères [M(SD)âge = 31,01(4,01) ans; 75,53% blanches] prenant soin d'un enfant de 11-60 mois ont été réparties au hasard pour participer soit au MIO soit à une psychoéducation. Les résultats de soins, les résultats psychiatriques et les résultats de toxicomanie ont été évalués de façon répétée de la base jusqu'au suivi à 12 semaines. Les mères ayant participé au MIO ont fait preuve d'une certitude diminuée à propos des états mentaux de leur enfant, et d'une dépression diminuée; leurs enfants ont fait preuve d'une clarté des indices accrue. La participation au MIO n'était pas liée au même degré d'amélioration qui a été observé dans les études préalables quand le MIO a été utilisé par des chercheurs cliniciens. Cependant, lorsqu'administré par des cliniciens communautaires, le MIO pourrait s'avérer protecteur d'une détérioration dans les soins au fil du temps que l'on voit souvent chez les mères toxicomanes. Le déclin d'efficacité du MIO dans cette étude soulève des questions quant à l'ajustement intervention-intervenant. Les recherches devraient se pencher sur les facteurs influençant l'efficacité du MIO pour réduire l'écart de la science au service dans la dissémination d'intervention validées empiriquement.

Multisite investigation of strategies for the clinical implementation of pre-emptive pharmacogenetic testing.

PURPOSE: The increased availability of clinical pharmacogenetic (PGx) guidelines and decreasing costs for genetic testing have slowly led to increased utilization of PGx testing in clinical practice. Pre-emptive PGx testing, where testing is performed in advance of drug prescribing, is one means to ensure results are available at the time of prescribing decisions. However, the most efficient and effective methods to clinically implement this strategy remain unclear. METHODS: In this report, we compare and contrast implementation strategies for pre-emptive PGx testing by 15 early-adopter institutions. We surveyed these groups, collecting data on testing approaches, team composition, and workflow dynamics, in addition to estimated third-party reimbursement rates. RESULTS: We found that while pre-emptive PGx testing models varied across sites, institutions shared several commonalities, including methods to identify patients eligible for testing, involvement of a precision medicine clinical team in program leadership, and the implementation of pharmacogenes with Clinical Pharmacogenetics Implementation Consortium guidelines available. Finally, while reimbursement rate data were difficult to obtain, the data available suggested that reimbursement rates for pre-emptive PGx testing remain low. CONCLUSION: These findings should inform the establishment of future implementation efforts at institutions considering a pre-emptive PGx testing program.

Transfer learning enables prediction of CYP2D6 haplotype function.

Cytochrome P450 2D6 (CYP2D6) is a highly polymorphic gene whose protein product metabolizes more than 20% of clinically used drugs. Genetic variations in CYP2D6 are responsible for interindividual heterogeneity in drug response that can lead to drug toxicity and ineffective treatment, making CYP2D6 one of the most important pharmacogenes. Prediction of CYP2D6 phenotype relies on curation of literature-derived functional studies to assign a functional status to CYP2D6 haplotypes. As the number of large-scale sequencing efforts grows, new haplotypes continue to be discovered, and assignment of function is challenging to maintain. To address this challenge, we have trained a convolutional neural network to predict functional status of CYP2D6 haplotypes, called Hubble.2D6. Hubble.2D6 predicts haplotype function from sequence data and was trained using two pre-training steps with a combination of real and simulated data. We find that Hubble.2D6 predicts CYP2D6 haplotype functional status with 88% accuracy in a held-out test set and explains 47.5% of the variance in in vitro functional data among star alleles with unknown function. Hubble.2D6 may be a useful tool for assigning function to haplotypes with uncurated function, and used for screening individuals who are at risk of being poor metabolizers.

Stargazer: a software tool for calling star alleles from next-generation sequencing data using CYP2D6 as a model.

PURPOSE: Genotyping CYP2D6 is important for precision drug therapy because the enzyme it encodes metabolizes approximately 25% of drugs, and its activity varies considerably among individuals. Genotype analysis of CYP2D6 is challenging due to its highly polymorphic nature. Over 100 haplotypes (star alleles) have been defined for CYP2D6, some involving a gene conversion with its nearby nonfunctional but highly homologous paralog CYP2D7. We present Stargazer, a new bioinformatics tool that uses next-generation sequencing (NGS) data to call star alleles for CYP2D6 ( https://stargazer.gs.washington.edu/stargazerweb/ ). Stargazer is currently being extended for other pharmacogenes. METHODS: Stargazer identifies star alleles from NGS data by detecting single nucleotide variants, insertion-deletion variants, and structural variants. Stargazer detects structural variation, including gene deletions, duplications, and conversions, by calculating paralog-specific copy numbers from read depths. RESULTS: We applied Stargazer to the NGS data of 32 ethnically diverse HapMap trios that were genotyped by TaqMan assays, long-range polymerase chain reaction, quantitative multiplex polymerase chain reaction, high-resolution melting analysis, and/or Sanger sequencing. CYP2D6 genotyping by Stargazer was 99.0% concordant with the data obtained by these methods, and showed that 28.1% of the samples had structural variation including CYP2D6/CYP2D7 hybrids. CONCLUSION: Accurate genotyping of pharmacogenes with NGS and subsequent allele calling with Stargazer will aid the implementation of precision drug therapy.

Mothering From the Inside Out: Results of a second randomized clinical trial testing a mentalization-based intervention for mothers in addiction treatment.

Mothers with histories of alcohol and drug addiction have shown greater difficulty parenting young children than mothers with no history of substance misuse. This study was the second randomized clinical trial testing the efficacy of Mothering From the Inside Out (MIO), a 12-week mentalization-based individual therapy designed to address psychological deficits commonly associated with chronic substance use that also interfere with the capacity to parent young children. Eighty-seven mothers caring for a child between 11 and 60 months of age were randomly assigned to receive 12 sessions of MIO versus 12 sessions of parent education (PE), a psychoeducation active control comparison. Maternal reflective functioning, representations of caregiving, mother-child interaction quality, and child attachment were evaluated at baseline and posttreatment and 3-month follow-up. Mother-child interaction quality was assessed again at 12-month follow-up. In comparison with PE mothers, MIO mothers demonstrated a higher capacity for reflective functioning and representational coherence at posttreatment and 3-month follow-up. At 12-month follow-up, compared to PE cohorts, MIO mothers demonstrated greater sensitivity, their children showed greater involvement, and MIO dyads showed greater reciprocity. As addiction severity increased, MIO also appeared to serve as a protective factor for maternal reflective functioning, quality of mother-child interactions, and child attachment status. Results demonstrate the promise of mentalization-based interventions provided concomitant with addiction treatment for mothers and their young children.

P-Glycoprotein Transport of Neurotoxic Pesticides.

P-glycoprotein (P-gp) has been associated with a number of neurodegenerative diseases, including Parkinson's disease, although the mechanisms remain unclear. Altered transport of neurotoxic pesticides has been proposed in Parkinson's disease, but it is unknown whether these pesticides are P-gp substrates. We used three in vitro transport models, stimulation of ATPase activity, xenobiotic-induced cytotoxicity, and inhibition of rhodamine-123 efflux, to evaluate P-gp transport of diazinon, dieldrin, endosulfan, ivermectin, maneb, 1-methyl-4-phenyl-4-phenylpyridinium ion (MPP(+)), and rotenone. Diazinon and rotenone stimulated ATPase activity in P-gp-expressing membranes, with Vmax values of 22.4 ± 2.1 and 16.8 ± 1.0 nmol inorganic phosphate/min per mg protein, respectively, and Km values of 9.72 ± 3.91 and 1.62 ± 0.51 µM, respectively, compared with the P-gp substrate verapamil, with a Vmax of 20.8 ± 0.7 nmol inorganic phosphate/min per mg protein and Km of 0.871 ± 0.172 µM. None of the other pesticides stimulated ATPase activity. We observed an increased resistance to MPP(+) and rotenone in LLC-MDR1-WT cells compared with LLC-vector cells, with 15.4- and 2.2-fold increases in EC50 values, respectively. The resistance was reversed in the presence of the P-gp inhibitor verapamil. None of the other pesticides displayed differential cytotoxicity. Ivermectin was the only pesticide to inhibit P-gp transport of rhodamine-123, with an IC50 of 0.249 ± 0.048 µM. Our data demonstrate that dieldrin, endosulfan, and maneb are not P-gp substrates or inhibitors. We identified diazinon, MPP(+), and rotenone as P-gp substrates, although further investigation is needed to understand the role of P-gp transport in their disposition in vivo and associations with Parkinson's disease.

Absence of P-glycoprotein transport in the pharmacokinetics and toxicity of the herbicide paraquat.

Genetic variation in the multidrug resistance gene ABCB1, which encodes the efflux transporter P-glycoprotein (P-gp), has been associated with Parkinson disease. Our goal was to investigate P-gp transport of paraquat, a Parkinson-associated neurotoxicant. We used in vitro transport models of ATPase activity, xenobiotic-induced cytotoxicity, transepithelial permeability, and rhodamine-123 inhibition. We also measured paraquat pharmacokinetics and brain distribution in Friend leukemia virus B-type (FVB) wild-type and P-gp-deficient (mdr1a(-/-)/mdr1b(-/-)) mice following 10, 25, 50, and 100 mg/kg oral doses. In vitro data showed that: 1) paraquat failed to stimulate ATPase activity; 2) resistance to paraquat-induced cytotoxicity was unchanged in P-gp-expressing cells in the absence or presence of P-gp inhibitors GF120918 [N-(4-[2-(1,2,3,4-tetrahydro-6,7-dimethoxy-2-isoquinolinyl)ethyl]-phenyl)-9,10-dihydro-5-methoxy-9-oxo-4-acridine carboxamide] and verapamil-37.0 [95% confidence interval (CI): 33.2-41.4], 46.2 (42.5-50.2), and 34.1 µM (31.2-37.2)-respectively; 3) transepithelial permeability ratios of paraquat were the same in P-gp-expressing and nonexpressing cells (1.55 ± 0.39 and 1.39 ± 0.43, respectively); and 4) paraquat did not inhibit rhodamine-123 transport. Population pharmacokinetic modeling revealed minor differences between FVB wild-type and mdr1a(-/-)/mdr1b(-/-) mice: clearances of 0.47 [95% confidence interval (CI): 0.42-0.52] and 0.78 l/h (0.58-0.98), respectively, and volume of distributions of 1.77 (95% CI: 1.50-2.04) and 3.36 liters (2.39-4.33), respectively; however, the change in clearance was in the opposite direction of what would be expected. It is noteworthy that paraquat brain-to-plasma partitioning ratios and total brain accumulation were the same across doses between FVB wild-type and mdr1a(-/-)/mdr1b(-/-) mice. These studies indicate that paraquat is not a P-gp substrate. Therefore, the association between ABCB1 pharmacogenomics and Parkinson disease is not attributed to alterations in paraquat transport.

MicroRNA-30c targets cytoskeleton genes involved in breast cancer cell invasion.

Metastasis remains a significant challenge in treating cancer. A better understanding of the molecular mechanisms underlying metastasis is needed to develop more effective treatments. Here, we show that human breast tumor biomarker miR-30c regulates invasion by targeting the cytoskeleton network genes encoding twinfilin 1 (TWF1) and vimentin (VIM). Both VIM and TWF1 have been shown to regulate epithelial-to-mesenchymal transition. Similar to TWF1, VIM also regulates F-actin formation, a key component of cellular transition to a more invasive mesenchymal phenotype. To further characterize the role of the TWF1 pathway in breast cancer, we found that IL-11 is an important target of TWF1 that regulates breast cancer cell invasion and STAT3 phosphorylation. The miR-30c-VIM/TWF1 signaling cascade is also associated with clinical outcome in breast cancer patients.

Lessons from clinical implementation of a preemptive pharmacogenetic panel as part of a testing pilot program with an employer-sponsored medical plan.

Introduction: This manuscript reports on a pilot program focused on implementing pharmacogenetic testing within the framework of an employer-sponsored medical plan at University of Florida (UF) Health. The aim was to understand the challenges associated with program implementation and to gather insights into patient attitudes towards PGx testing. Methods: The pilot program adopted a partially preemptive approach, targeting patients on current prescriptions for medications with relevant gene-drug associations. Patients were contacted via phone or through the MyChart system and offered pharmacogenetic testing with no additional direct costs. Results: Of 244 eligible patients, 110 agreed to participate. However, only 61 returned the mailed DNA collection kits. Among these, 89% had at least one potentially actionable genotype-based phenotype. Post-test follow-up revealed that while the majority viewed the process positively, 71% preferred a consultation with a pharmacogenetic specialist for better understanding of their results. Barriers to implementation ranged from fatigue with the healthcare system to a lack of understanding of the pharmacogenetic testing and concerns about privacy and potential misuse of genetic data. Conclusion: The findings underscore the need for clearer patient education on pharmacogenetic results and suggest the importance of the role of pharmacogenetic-trained pharmacists in delivering this education. They also highlight issues with relying on incomplete or inaccurate medication lists in patients' electronic health record. The implementation revealed less obvious challenges, the understanding of which could be beneficial for the success of future preemptive pharmacogenetic implementation programs. The insights from the pilot program served to bridge the information gap between patients, providers, and pharmacogenetic -specialists, with the ultimate goal of improving patient care.

Implementation of CYP2C19 genotyping to guide proton pump inhibitor use at an academic health center.

PURPOSE: To describe the implementation of CYP2C19 testing into clinical practice at University of Florida (UF) Health Gainesville hospital to guide proton pump inhibitor (PPI) dosing and the lessons learned from this experience. SUMMARY: Different CYP2C19 genotypes are associated with variability in PPI plasma concentrations and intragastric pH, which may contribute to the risk of treatment failure due to subtherapeutic concentrations and adverse effects (eg, infection, bone fracture, renal dysfunction) with sustained supratherapeutic concentrations. Based on evidence available prior to the availability of pertinent Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines, the UF Health Precision Medicine Program (PMP) developed clinical recommendations, provided through automated alerts at the time of a PPI order, to (1) increase the PPI dose for individuals with genotypes linked to increased CYP2C19 enzyme activity (ie, rapid and ultrarapid metabolizers) to improve the likelihood of drug effectiveness and (2) decrease the dose for individuals with decreased CYP2C19 activity (ie, intermediate and poor metabolizers) to reduce the risk of harm. The CYP2C19-PPI implementation was an iterative process that taught us key implementation lessons. Most notably, physician engagement is essential, problem lists in the medical record are unreliable, and special populations (eg, pediatric patients) need to be considered. CONCLUSION: Guiding PPI prescribing based on CYP2C19 genotype is a practical approach to potentially improve the benefit-risk ratio with PPI therapy. Physician engagement is key for successful implementation. A CPIC guideline on CYP2C19 genotype-guided PPI dosing is now available, and automated alerts may be instituted to facilitate implementation.

Assessment of a Manual Method versus an Automated, Probability-Based Algorithm to Identify Patients at High Risk for Pharmacogenomic Adverse Drug Outcomes in a University-Based Health Insurance Program.

We compared patient cohorts selected for pharmacogenomic testing using a manual method or automated algorithm in a university-based health insurance network. The medication list was compiled from claims data during 4th quarter 2018. The manual method selected patients by number of medications by the health system's list of medications for pharmacogenomic testing. The automated method used YouScript's pharmacogenetic interaction probability (PIP) algorithm to select patients based on the probability that testing would result in detection of one or more clinically significant pharmacogenetic interactions. A total of 6916 patients were included. Patient cohorts selected by each method differed substantially, including size (manual n = 218, automated n = 286) and overlap (n = 41). The automated method was over twice as likely to identify patients where testing may reveal a clinically significant pharmacogenetic interaction than the manual method (62% vs. 29%, p < 0.0001). The manual method captured more patients with significant drug-drug or multi-drug interactions (80.3% vs. 40.2%, respectively, p < 0.0001), higher average number of significant drug interactions per patient (3.3 vs. 1.1, p < 0.0001), and higher average number of unique medications per patient (9.8 vs. 7.4, p < 0.0001). It is possible to identify a cohort of patients who would likely benefit from pharmacogenomic testing using manual or automated methods.

Patients with geographic barriers to health care access are prescribed a higher proportion of drugs with pharmacogenetic testing guidelines.

Pharmacogenetic (PGx) testing may be particularly beneficial in medically underserved populations by reducing the number of appointments required to optimize drug therapy and increasing the effectiveness of less expensive off-patent drugs. The objective of this study was to identify patient populations with poor health care access and assess prescribing trends for drugs with published PGx testing guidelines. We used electronic health record data from 67,753 University of Florida Health patients, geographic access scores calculated via the 2-step floating catchment area method, and a composite measure of socioeconomic status. Comparing the poorest (Q4) and greatest (Q1) access score quartiles, poor geographic access was significantly associated with fewer prescriber encounters (incidence rate ratio [IRR] 0.88, 95% confidence interval [CI] 0.86-0.91), fewer total unique drugs (IRR 0.92, 95% CI 0.9-0.95), and fewer PGx guideline drugs (IRR 0.94, 95% CI 0.9-0.99). After correcting for number of unique drugs, patients in low-access areas were prescribed a greater proportion of PGx guideline drugs (IRR 1.08, 95% CI 1.04-1.13). We detected significant interactions between Black race and access score. Compared to Q1, Black patients with Q4 access scores were disproportionately affected and had fewer encounters (IRR 0.76, 95% CI 0.7-0.82) and a higher proportion of PGx drugs (IRR 1.26, 95% CI 1.13-1.41), creating further disparity. Overall, these results suggest that improved geographic access to PGx testing may allow prescribers to make more efficient use of limited opportunities to optimize therapy for drugs with PGx testing guidelines.

Characterization of CYP3A pharmacogenetic variation in American Indian and Alaska Native communities, targeting CYP3A4*1G allele function.

The frequencies of genetic variants in the CYP3A4 and CYP3A5 genes differ greatly across global populations, leading to profound differences in the metabolic activity of these enzymes and resulting drug metabolism rates, with important consequences for therapeutic safety and efficacy. Yet, the impact of genetic variants on enzyme activity are incompletely described, particularly in American Indian and Alaska Native (AIAN) populations. To characterize genetic variation in CYP3A4 and CYP3A5 and its effect on enzyme activity, we partnered with AIAN people living in two regions of Alaska: Yup'ik Alaska Native people living in the Yukon-Kuskokwim Delta region of rural southwest Alaska and AIAN people receiving care at the Southcentral Foundation in Anchorage, Alaska. We identified low frequencies of novel and known variation in CYP3A4 and CYP3A5, including low frequencies of the CYP3A4*1G and CYP3A5*1 variants, and linkage disequilibrium patterns that differed from those we previously identified in an American Indian population in western Montana. We also identified increased activity of the CYP3A4*1G allele in vitro and in vivo. We demonstrated that the CYP3A4*1G allele confers increased protein content in human lymphoblastoid cells and both increased protein content and increased activity in human liver microsomes. We confirmed enhanced CYP3A4-mediated 4ß-vitamin D hydroxylation activity in Yup'ik people with the CYP3A4*1G allele. AIAN people in Alaska and Montana who carry the CYP3A4*1G allele-coupled with low frequency of the functional CYP3A5*1 variant-may metabolize CYP3A substrates more rapidly than people with the reference CYP3A4 allele.

Interrogation of CYP2D6 Structural Variant Alleles Improves the Correlation Between CYP2D6 Genotype and CYP2D6-Mediated Metabolic Activity.

The cytochrome P450 2D6 (CYP2D6) gene locus is challenging to accurately genotype due to numerous single nucleotide variants and complex structural variation. Our goal was to determine whether the CYP2D6 genotype-phenotype correlation is improved when diplotype assignments incorporate structural variation, identified by the bioinformatics tool Stargazer, with next-generation sequencing data. Using CYP2D6 activity measured with substrates dextromethorphan and metoprolol, activity score explained 40% and 34% of variability in metabolite formation rates, respectively, when diplotype calls incorporated structural variation, increasing from 36% and 31%, respectively, when diplotypes did not incorporate structural variation. We also investigated whether the revised Clinical Pharmacogenetics Implementation Consortium (CPIC) recommendations for translating genotype to phenotype improve CYP2D6 activity predictions over the current system. Although the revised recommendations do not improve the correlation between activity score and CYP2D6 activity, perhaps because of low frequency of the CYP2D6*10 allele, the correlation with metabolizer phenotype group was significantly improved for both substrates. We also measured the function of seven rare coding variants: one (A449D) exhibited decreased (44%) and another (R474Q) increased (127%) activity compared with reference CYP2D6.1 protein. Allele-specific analysis found that A449D is part of a novel CYP2D6*4 suballele, CYP2D6*4.028. The novel haplotype containing R474Q was designated CYP2D6*138 by PharmVar; another novel haplotype containing R365H was designated CYP2D6*139. Accuracy of CYP2D6 phenotype prediction is improved when the CYP2D6 gene locus is interrogated using next-generation sequencing coupled with structural variation analysis. Additionally, revised CPIC genotype to phenotype translation recommendations provides an improvement in assigning CYP2D6 activity.

miR-206 Inhibits Stemness and Metastasis of Breast Cancer by Targeting MKL1/IL11 Pathway.

Purpose: Effective targeting of cancer stem cells is necessary and important for eradicating cancer and reducing metastasis-related mortality. Understanding of cancer stemness-related signaling pathways at the molecular level will help control cancer and stop metastasis in the clinic.Experimental Design: By analyzing miRNA profiles and functions in cancer development, we aimed to identify regulators of breast tumor stemness and metastasis in human xenograft models in vivo and examined their effects on self-renewal and invasion of breast cancer cells in vitro To discover the direct targets and essential signaling pathways responsible for miRNA functions in breast cancer progression, we performed microarray analysis and target gene prediction in combination with functional studies on candidate genes (overexpression rescues and pheno-copying knockdowns).Results: In this study, we report that hsa-miR-206 suppresses breast tumor stemness and metastasis by inhibiting both self-renewal and invasion. We identified that among the candidate targets, twinfilin (TWF1) rescues the miR-206 phenotype in invasion by enhancing the actin cytoskeleton dynamics and the activity of the mesenchymal lineage transcription factors, megakaryoblastic leukemia (translocation) 1 (MKL1), and serum response factor (SRF). MKL1 and SRF were further demonstrated to promote the expression of IL11, which is essential for miR-206's function in inhibiting both invasion and stemness of breast cancer.Conclusions: The identification of the miR-206/TWF1/MKL1-SRF/IL11 signaling pathway sheds lights on the understanding of breast cancer initiation and progression, unveils new therapeutic targets, and facilitates innovative drug development to control cancer and block metastasis. Clin Cancer Res; 23(4); 1091-103. ©2016 AACR.

MicroRNA-30c inhibits human breast tumour chemotherapy resistance by regulating TWF1 and IL-11.

Chemotherapy resistance frequently drives tumour progression. However, the underlying molecular mechanisms are poorly characterized. Epithelial-to-mesenchymal transition has been shown to correlate with therapy resistance, but the functional link and signalling pathways remain to be elucidated. Here we report that microRNA-30c, a human breast tumour prognostic marker, has a pivotal role in chemoresistance by a direct targeting of the actin-binding protein twinfilin 1, which promotes epithelial-to-mesenchymal transition. An interleukin-6 family member, interleukin-11 is identified as a secondary target of twinfilin 1 in the microRNA-30c signalling pathway. Expression of microRNA-30c inversely correlates with interleukin-11 expression in primary breast tumours and low interleukin-11 correlates with relapse-free survival in breast cancer patients. Our study demonstrates that microRNA-30c is transcriptionally regulated by GATA3 in breast tumours. Identification of a novel microRNA-mediated pathway that regulates chemoresistance in breast cancer will facilitate the development of novel therapeutic strategies.

Removal of lactate dehydrogenase-elevating virus from human-in-mouse breast tumor xenografts by cell-sorting.

Lactate dehydrogenase-elevating virus (LDV) can infect transplantable mouse tumors or xenograft tumors in mice through LDV-contaminated mouse biological materials, such as Matrigel, or through mice infected with LDV. LDV infects specifically mouse macrophages and alters immune system and tumor phenotype. The traditional approaches to remove LDV from tumor cells, by transplanting tumors into rats or culturing tumor cells in vitro, are inefficient, labor-intensive and time-consuming. Furthermore, these approaches are not feasible for primary tumor cells that cannot survive tissue culture conditions or that may change phenotype in rats. This study reports that fluorescence-activated cell sorting (FACS) is a simple and efficient approach for purifying living primary human breast tumor cells from LDV(+) mouse stromal cells, which can be completed in a few hours. When purified from Matrigel contaminated LDV(+) tumors, sorted human breast tumor cells, as well as tumors grown from sorted cells, were shown to be LDV-free, as tested by PCR. The results demonstrate that cell sorting is effective, much faster and less likely to alter tumor cell phenotype than traditional methods for removing LDV from xenograft models. This approach may also be used to remove other rodent-specific viruses from models derived from distinct tissues or species with sortable markers, where virus does not replicate in the cells to be purified.