Impact of Surface Hydroxyl Groups on CuO Film Growth by Atomic Layer Deposition.

CuO-based nanostructures have been widely investigated in catalysis, sensing, and energy conversion and storage in recent years. The unique properties of these nanostructures are largely related to the morphology and crystallinity of CuO. The controlled deposition of conformal CuO thin films by atomic layer deposition (ALD) has remained challenging until now owing to the limited understanding of the nucleation behavior and growth process. Here, a novel ALD process for copper oxide was developed using copper(II) trifluoroacetylacetonate [Cu(tfacac)2] as the metal precursor. The nucleation and initial growth of a CuO film are strongly dependent on the surface OH concentration. A continuous particulate-like CuO film was grown on OH-abundant pristine SiO2 particles, whereas the surface of the annealed SiO2 particles (presenting mostly isolated OH groups) remained uncoated under the same growth conditions. Moreover, a uniform and conformal CuO film was grown on covalently functionalized CNTs under identical conditions as pristine SiO2 particles. This study provides a strategy for tailoring the structure and the properties of thin films via ALD, which is promising for designing well-tailored nanostructures for various applications.

Stabilization of Titanium Dioxide Nanoparticles at the Surface of Carbon Nanomaterials Promoted by Microwave Heating.

TiO2 is frequently combined with carbon materials, such as reduced graphene oxide (RGO), to produce composites with improved properties, for example for photocatalytic applications. It is shown that heating conditions significantly affect the interface and photocatalytic properties of TiO2 @C, and that microwave irradiation can be advantageous for the synthesis of carbon-based materials. Composites of TiO2 with RGO or amorphous carbon were prepared from reaction of titanium isopropoxide with benzyl alcohol. During the synthesis of the TiO2 nanoparticles, the carbon is involved in reactions that lead to the covalent attachment of the oxide, the extent of which depends on the carbon characteristics, heating rate, and mechanism. TiO2 is more efficiently stabilized at the surface of RGO than amorphous carbon. Rapid heating of the reaction mixture results in a stronger coupling between the nanoparticles and carbon, more uniform coatings, and smaller particles with narrower size distributions. The more efficient attachment of the oxide leads to better photocatalytic performance.

Adsorption of n-pentane on mesoporous silica and adsorbent deformation.

Development of quantitative theory of adsorption-induced deformation is important, e.g., for enhanced coalbed methane recovery by CO2 injection. It is also promising for the interpretation of experimental measurements of elastic properties of porous solids. We study deformation of mesoporous silica by n-pentane adsorption. The shape of experimental strain isotherms for this system differs from the shape predicted by thermodynamic theory of adsorption-induced deformation. We show that this difference can be attributed to the difference of disjoining pressure isotherm, responsible for the solid-fluid interactions. We suggest the disjoining pressure isotherm suitable for n-pentane adsorption on silica and derive the parameters for this isotherm from experimental data of n-pentane adsorption on nonporous silica. We use this isotherm in the formalism of macroscopic theory of adsorption-induced deformation of mesoporous materials, thus extending this theory for the case of weak solid-fluid interactions. We employ the extended theory to calculate solvation pressure and strain isotherms for SBA-15 and MCM-41 silica and compare it with experimental data obtained from small-angle X-ray scattering. Theoretical predictions for MCM-41 are in good agreement with the experiment, but for SBA-15 they are only qualitative. This deviation suggests that the elastic modulus of SBA-15 may change during pore filling.

Single-Step Formation of Metal Oxide Nanostructures Wrapped in Mesoporous Silica and Silica-Niobia Catalysts for the Condensation of Furfural with Acetone.

The integration of metal oxide nanomaterials with mesoporous silica is a promising approach to exploiting the advantages of both types of materials. Traditional synthesis methods typically require multiple steps. This work instead presents a fast, one-step, template-free method for the synthesis of metal oxides homogeneously dispersed within mesoporous silica, including oxides of W, Ti, Nb, Ta, Sn, and Mo. These composites have tunable metal oxide contents, large surface areas, and wide mesopores. The combination of Nb2O5 nanoparticles (NPs) with SiO2 results in an increased surface area and a larger number of acid sites compared to pure Nb2O5 NPs. The surface texture and acidity of the silica-niobia composites can be tuned by adjusting the Nb/Si molar ratio. Moreover, the silica provides protection to the niobia NPs, preventing sintering during thermal treatment at 400 °C. The silica-niobia materials exhibit superior performance as catalysts in the aldol condensation of furfural (Fur) with acetone compared to pure niobia, leading to an up to 62% in product yield. Additionally, these catalysts show remarkable stability, retaining their performance over multiple runs. This work demonstrates the potential of the proposed synthesis approach for preparing more sustainable, high-performance, durable, and stable nanoscale metal oxide-based catalysts with a tunable composition, surface area, and active site density.

Pregnancy-induced chromatin remodeling in the breast of postmenopausal women.

Early pregnancy and multiparity are known to reduce the risk of women to develop breast cancer at menopause. Based on the knowledge that the differentiation of the breast induced by the hormones of pregnancy plays a major role in this protection, this work was performed with the purpose of identifying what differentiation-associated molecular changes persist in the breast until menopause. Core needle biopsies (CNB) obtained from the breast of 42 nulliparous (NP) and 71 parous (P) postmenopausal women were analyzed in morphology, immunocytochemistry and gene expression. Whereas in the NP breast, nuclei of epithelial cells were large and euchromatic, in the P breast they were small and hyperchromatic, showing strong methylation of histone 3 at lysine 9 and 27. Transcriptomic analysis performed using Affymetrix HG_U133 oligonucleotide arrays revealed that in CNB of the P breast, there were 267 upregulated probesets that comprised genes controlling chromatin organization, transcription regulation, splicing machinery, mRNA processing and noncoding elements including XIST. We concluded that the differentiation process induced by pregnancy is centered in chromatin remodeling and in the mRNA processing reactome, both of which emerge as important regulatory pathways. These are indicative of a safeguard step that maintains the fidelity of the transcription process, becoming the ultimate mechanism mediating the protection of the breast conferred by full-term pregnancy.

Room-temperature hydrogen sensing with heteronanostructures based on reduced graphene oxide and tin oxide.

There's something in the air … A nanocomposite consisting of well-dispersed SnO(2) and Pt nanoparticles on reduced graphene oxide (see the high-resolution TEM image) exhibited very high responses to hydrogen at concentrations between 0.5 and 3% in air, with response times of 3-7 s and recovery times of 2-6 s. The sensor was prepared by a straightforward microwave-assisted non-aqueous sol-gel approach.

Volatile organic compound adsorption on a nonporous silica surface: how do different probe molecules sense the same surface?

In this work, we compare experimental results to molecular simulation results of volatile organic compound (VOC) adsorption on nonporous silica. We adopted an effective model for the rough solid surface, obtained by a temperature annealing scheme, plus an experimental/simulation nitrogen adsorption tuning process over the silica energetic oxygen parameter. The measurement/prediction of selected VOCs, specifically, n-pentane and methylcyclohexane, is presented in terms of adsorption isotherms, with an emphasis on the angle distribution analysis of the three studied probe molecules with respect to the same modeled surface.

Recent Advances in Multimetal and Doped Transition-Metal Phosphides for the Hydrogen Evolution Reaction at Different pH values.

Hydrogen is a fuel with a potentially zero-carbon footprint viewed as a viable alternative to fossil fuels. It can be produced in a large scale via electrochemical water splitting using electricity derived from renewable sources, but this would require highly active, inexpensive, and stable hydrogen evolution reaction (HER) catalysts to replace the Pt benchmark. Transition-metal phosphides (TMPs) are potential Pt replacements owing to their generally high activity as well as versatility as HER catalysts for different pH media. This review summarizes the recent progress in the development of TMP HER electrocatalysts, focusing on the strategies that have been recently explored to tune the activity in acidic, neutral, and basic media. These strategies are the doping of TMPs with metal and nonmetal elements, fabrication of multimetallic phosphide phases, and construction of multicomponent heterostructures comprising TMPs and another component such as a different TMP or a metal oxide/hydroxide. The synthetic methods utilized to design the catalysts are also presented. Finally, the challenges still remaining and future research directions are discussed.

Health care resource utilization and disease modifying treatment use in multiple sclerosis patients by age and insurance type.

OBJECTIVE: The objective of this study was to describe and compare health care resource utilization (HCRU) and disease modifying treatment (DMT) use among US adults <65 years with multiple sclerosis (MS), across commercial and Medicare Advantage plans. METHODS: Medical and pharmacy claims data from commercial and Medicare Advantage with Part D (MAPD) plans were extracted for MS patients age 18 - 64 identified between 1 January 2014 and 31 May 2017. Comparisons were made between commercial and MAPD enrollees for all-cause HCRU and DMT use over 1 year, overall and by 5 year age groups. RESULTS: A total of 28,427 MS patients were identified; two-thirds (67%) had commercial coverage. MAPD patients had statistically significantly higher mean counts of all-cause inpatient, emergency room (ER) and ambulatory visits compared to commercial patients. The significant differences were evident in all age groups ≥30 years, except for ER visits in the 40-44 and 60-64 age groups. MAPD patients had statistically significantly lower prevalence of DMT use compared to commercial patients in all age groups starting at ≥35 years. CONCLUSION: MAPD patients had a higher burden of medical HCRU compared to their commercially insured counterparts, most likely due primarily to their more advanced disease state and higher level of MS-related disability. Reasons for lower prevalence of DMT use among MAPD patients may include their more advanced disease state, older age and higher prevalence of comorbid conditions compared with commercially insured patients, as well as more restrictive formularies for MAPD vs. commercial plans. These findings suggest that there may be an opportunity for recently approved DMTs indicated for active secondary progressive MS to fulfill an unmet need for treatment among MS patients <65 years without contraindicated comorbid conditions who are enrolled in MAPD plans. Novel therapies under development to delay progression may help keep MS patients of working age in the work force.

Patients' Experiences in Transitioning to Secondary Progressive Multiple Sclerosis: Qualitative Interviews.

INTRODUCTION: Critical gaps exist in the understanding of the continuum of multiple sclerosis (MS) progression, particularly with regard to the patient experience prior to and during the transition from relapsing-remitting MS (RRMS) to secondary-progressive MS (SPMS) stages. To date, there are no clear diagnostic criteria in the determination of the clinical transition. We report here the use of patient experience data to support the development of a qualitative conceptual model of MS that describes the patient journey of transition from active-relapsing disease to progressive MS. METHODS: The study used a single-encounter, multicenter, qualitative observational study design that included a targeted literature review and individual, in-depth interviews with adult patients with a clinically confirmed diagnosis of SPMS and their adult care partners. Descriptions of symptoms and impacts of RRMS and SPMS were extracted from the literature review and used to support development of the interview guide and conceptual model. RESULTS: Participants described a slow progression in terms of change in symptoms over time, including both the development of new symptoms and the worsening of existing symptoms. CONCLUSIONS: The conceptual model of the transitionary period from RRMS to SPMS expands the current understanding of the progression of MS from the patient and care partner perspectives.

Sacubitril/Valsartan Initiation Among Veterans Who Are Renin-Angiotensin-Aldosterone System Inhibitor Naïve With Heart Failure and Reduced Ejection Fraction.

Background Sacubitril/valsartan, a first-in-class angiotensin receptor neprilysin inhibitor, received US Food and Drug Administration approval in 2015 for heart failure with reduced ejection fraction (HFrEF). Our objective was to describe the sacubitril/valsartan initiation rate, associated characteristics, and 6-month follow-up dosing among veterans with HFrEF who are renin-angiotensin-aldosterone system inhibitor (RAASi) naïve. Methods and Results Retrospective cohort study of veterans with HFrEF who are RAASi naïve defined as left ventricular ejection fraction (LVEF) ≤40%; ≥1 in/outpatient heart failure visit, first RAASi (sacubitril/valsartan, angiotensin-converting enzyme inhibitor [ACEI]), or angiotensin-II receptor blocker [ARB]) fill from July 2015 to June 2019. Characteristics associated with sacubitril/valsartan initiation were identified using Poisson regression models. From July 2015 to June 2019, we identified 3458 sacubitril/valsartan and 29 367 ACEI or ARB initiators among veterans with HFrEF who are RAASi naïve. Sacubitril/valsartan initiation increased from 0% to 26.5%. Sacubitril/valsartan (versus ACEI or ARB) initiators were less likely to have histories of stroke, myocardial infarction, or hypertension and more likely to be older and have diabetes mellitus and lower LVEF. At 6-month follow-up, the prevalence of ≥50% target daily dose for sacubitril/valsartan, ACEI, and ARB initiators was 23.5%, 43.2%, and 47.1%, respectively. Conclusions Sacubitril/valsartan initiation for HFrEF in the Veterans Administration increased in the 4 years immediately following Food and Drug Administration approval. Sacubitril/valsartan (versus ACEI or ARB) initiators had fewer baseline cardiovascular comorbidities and the lowest proportion on ≥50% target daily dose at 6-month follow-up. Identifying the reasons for lower follow-up dosing of sacubitril/valsartan could support guideline recommendations and quality improvement strategies for patients with HFrEF.

Correlates of sexually related personal distress in women with low sexual desire.

INTRODUCTION: Sexual distress is an important component of diagnostic criteria for sexual dysfunctions, but little is known about the factors associated with sexual distress in women with low sexual desire. AIM: To investigate the correlates of sexual distress in women with self-reported low sexual desire. METHODS: The Prevalence of Female Sexual Problems Associated with Distress and Determinants of Treatment Seeking study was a cross-sectional, nationally representative, mailed survey of U.S. adult women. There were 31,581 respondents (response rate 63.2%) to the 42-item questionnaire that measured sexual function, sexual distress, demographic, and health-related factors. Multivariable logistic regression was used to explore the correlates of distress. MAIN OUTCOME MEASURES: Low sexual desire was defined as a response of "never" or "rarely" to the question, "How often do you desire to engage in sexual activity?" Sexual distress was measured with the Female Sexual Distress Scale (range 0-48), with a score of 15 or higher indicating presence of distress. RESULTS: Of 10,429 women with low desire, 2,868 (27.5%) had sexual distress (mean age 48.6 years, 81% with a current partner). Women without distress were 10 years older on average, and 44% had a current partner. Having a partner was strongly related to distress (odds ratio 4.6, 95% confidence interval 4.1-5.2). Other correlates were age, race, current depression, anxiety, lower social functioning, hormonal medication use, urinary incontinence, and concurrent sexual problems (arousal or orgasm). Dissatisfaction with sex life was more common in women with low desire and distress (65%) than in those without distress (20%). CONCLUSIONS: Age has a curvilinear relationship with distress, and the strongest correlate of sexual distress was having a current partner. Sexual distress and dissatisfaction with sex life are strongly correlated. Distress is higher in women with low sexual desire in a partner relationship; further research on this factor is needed.

Characteristics and Healthcare Utilization Among Veterans Treated for Heart Failure With Reduced Ejection Fraction Who Switched to Sacubitril/Valsartan.

BACKGROUND: US guidelines recommend that patients with heart failure with reduced ejection fraction (HFrEF), who tolerate an ACEI (angiotensin-converting enzyme inhibitor) or ARB (angiotensin II receptor blocker), be switched to sacubitril/valsartan to reduce morbidity and mortality. We compared characteristics and healthcare utilization between Veterans with HFrEF who were switched to sacubitril/valsartan versus maintained on an ACEI or ARB. METHODS: retrospective cohort study of treated HFrEF (July 2015-June 2017) using Veterans Affairs data. The index date was the first fill for sacubitril/valsartan and if none, for an ACEI or ARB. Treated HFrEF was defined by (1) left ventricular ejection fraction ≤40%, (2) ≥1 in/outpatient HF encounter, and (3) ≥1 ACEI or ARB fill, all within 1-year preindex. Poisson regression models were used to compare baseline characteristics and 1:1 propensity score-matched adjusted 4-month follow-up healthcare utilization between sacubitril/valsartan switchers and ACEI or ARB maintainers. RESULTS: Switchers (1612; 4.2%) were less likely than maintainers (37 065; 95.8%) to have a history of myocardial infarction or hypertension, and more likely to be black, have a lower left ventricular ejection fraction, and higher preindex healthcare utilization. Switchers were less likely to experience follow-up all-cause hospitalizations (11.2% versus 14.0%; risk ratio 0.80 [95% CI, 0.65-0.98], P value 0.035). CONCLUSIONS: Few Veterans with treated HFrEF were switched to sacubitril/valsartan within the first 2 years of Food and Drug Administration approval. Sacubitril/valsartan use was associated with a lower risk for all-cause hospitalizations at 4 months follow-up. Reasons for lack of guideline-recommended sacubitril/valsartan initiation warrant investigation and may reveal opportunities for HFrEF care optimization.

ERbeta shifts from mitochondria to nucleus during estrogen-induced neoplastic transformation of human breast epithelial cells and is involved in estrogen-induced synthesis of mitochondrial respiratory chain proteins.

Both estrogen receptors (ER) alpha (ERalpha) and beta (ERbeta) are localized in the nucleus, plasma membrane, and mitochondria, where they mediate the different physiological effects of estrogens. It has been observed that the relative subcellular localization of ERs is altered in several cancer cells. We have demonstrated that MCF-10F cells, the immortal and non-tumorigenic human breast epithelial cells (HBEC) that are ERalpha-negative and ERbeta-positive, are transformed in vitro by 17beta-estradiol (E(2)), generating highly invasive cells that are tumorigenic in severe combined immunodeficient mice. E(2)-transformed MCF-10F (trMCF) cells exhibit progressive loss of ductulogenesis, invasive (bsMCF) and tumorigenic (caMCF) phenotypes. Immunolocalization of ERbeta by confocal fluorescent microscopy and electron microscopy revealed that ERbeta is predominantly localized in mitochondria of MCF-10F and trMCF cells. Silencing ERbeta expression with ERbeta-specific small interference RNA (siRNA-ERbeta) markedly diminishes both nuclear and mitochondrial ERbeta in MCF-10F cells. The ERbeta shifts from its predominant localization in the mitochondria of MCF-10F and trMCF cells to the nucleus of bsMCF cells, becoming predominantly nuclear in caMCF cells. Furthermore, we demonstrated that the mitochondrial ERbeta in MCF-10F cells is involved in E(2)-induced expression of mitochondrial DNA (mtDNA)-encoded respiratory chain (MRC) proteins. This is the first report of an association of changes in the subcellular localization of ERbeta with various stages of E(2)-induced transformation of HBEC and a functional role of mitochondrial ERbeta in mediating E(2)-induced MRC protein synthesis. Our findings provide a new insight into one of the potential roles of ERbeta in human breast cancer.

Sexual problems and distress in United States women: prevalence and correlates.

OBJECTIVE: To estimate the prevalence of self-reported sexual problems (any, desire, arousal, and orgasm), the prevalence of problems accompanied by personal distress, and to describe related correlates. METHODS: The 31,581 female respondents aged 18 years and older were from 50,002 households sampled from a national research panel representative of U.S. women. Correlates of each distressing sexual problem were evaluated using multiple logistic regression techniques. RESULTS: The age-adjusted point prevalence of any sexual problem was 43.1% and 22.2% for sexually related personal distress (defined as a score of at least 15 on Female Sexual Distress Scale). Any distressing sexual problem (defined as reporting both a sexual problem and sexually related personal distress, Female Sexual Distress Scale score of at least 15) occurred in 12.0% of respondents and was more common in women aged 45-64 years (14.8%) than in younger (10.8%) or older (8.9%) women. Correlates of distressing sexual problems included poor self-assessed health, low education level, depression, anxiety, thyroid conditions, and urinary incontinence. CONCLUSION: The prevalence of distressing sexual problems peaked in middle-aged women and was considerably lower than the prevalence of sexual problems. This underlines the importance of assessing the prevalence of sexually related personal distress in accurately estimating the prevalence of sexual problems that may require clinical intervention. LEVEL OF EVIDENCE: III.

Cobalt-Assisted Morphology and Assembly Control of Co-Doped ZnO Nanoparticles.

The morphology of metal oxide nanostructures influences the response of the materials in a given application. In addition to changing the composition, doping can also modify the morphology of a host nanomaterial. Herein, we determine the effect of dopant concentration, reaction temperature, and reaction time on the morphology and assembly of CoxZn1−xO nanoparticles synthesized through non-aqueous sol-gel in benzyl alcohol. With the increase of the atom % of cobalt incorporated from 0 to 15, the shape of the nanoparticles changes from near spherical, to irregular, and finally to triangular. The tendency of the particles to assemble increases in the same direction, with Co0.05Zn0.95O consisting of non-assembled particles, whereas Co0.15Zn0.85O consists of triangular nanoparticles forming spherical structures. The morphology and assembly process are also sensitive to the reaction temperature. The assembly process is found to occur during the nucleation or the early stages of particle growth. The cobalt ions promote the change in the shape during the growth stage of the nanoparticles.

An Early View of Real-World Patient Response to Sacubitril/Valsartan: A Retrospective Study of Patients with Heart Failure with Reduced Ejection Fraction.

INTRODUCTION: Sacubitril/valsartan has been established as an effective treatment for heart failure (HF) with reduced ejection fraction based on clinical trial data; however, little is known about its use or impact in real-world practice. METHODS: This study included data from medical and pharmacy claims and medical records review for patients (n = 200) who initiated sacubitril/valsartan between August 2015 and March 2016 preceding issuance of American College of Cardiology (ACC)/American Heart Association (AHA)/Heart Failure Society of America (HFSA) focused update on new pharmacological therapy for HF (May 2016), which included recommendations for sacubitril/valsartan. A within-subject analysis compared symptoms and healthcare resource utilization before and after treatment initiation. RESULTS: Patients treated with sacubitril/valsartan had multiple comorbidities, and nearly all had previous treatment for HF. Most patients initiated sacubitril/valsartan at the lowest dose of 24/26 mg twice a day (BID), which remained unchanged during the observation period for half of the patients. During the first 6 weeks of treatment, few patients discontinued sacubitril/valsartan treatment (5.5%), and only 17% achieved the target dose of 97/103 mg BID after 4 months of treatment. The proportion of patients with ≥ 1 all-cause inpatient stay decreased significantly between the pre-initiation period (27.5%) and the post-initiation period (17.0%), P = 0.009. Fatigue was noted in 51.8% of patients pre-initiation and 39.5% post-initiation, P = 0.027. Shortness of breath was documented for 66.7% of patients pre-initiation and 51.8% post-initiation, P = 0.008. CONCLUSION: The findings of this real-world investigation suggest sacubitril/valsartan is associated with symptom improvements and a reduction in hospitalizations within 4 months of treatment for patients with HF and reduced ejection fraction. FUNDING: Novartis Pharmaceuticals Corporation.

The breast of parous women without cancer has a different genomic profile compared to those with cancer.

Our studies are aimed at determining whether pregnancy induces a specific genomic signature in the postmenopausal breast that is responsible for the protective effect elicited by this physiological process. For this purpose we designed a study to compare the gene expression profiles in normal breast tissue from parous postmenopausal women with (case) and without (control) breast cancer. We have used breast samples from 18 parous controls and 41 parous cases. The epithelium and the interlobular stroma were dissected using laser capture microdissection and the RNA of each compartment and each sample was isolated, amplified using PCR methodology, and hybridized to cDNA glass-microarrays containing 40,000 genes, placing the human reference RNA in the green channel (Cy3) and the breast tissue samples in the red channel (Cy5). The normalization and statistical analysis of the expression data were carried out by using the LIMMA software package for the R programming environment which provides functions to summarize the results using the linear model perform hypothesis tests and adjust the p-values for multiple testing. We were able to identify 126 genes that were upregulated and 103 that were downregulated in the parous control group. There were only 56 genes differentially expressed in the interlobular stroma in the parous control group in relation to the other group of women under study. The gene categories that were overrepresented in the breast epithelium of the parous control breast are related to apoptosis, DNA repair, response to exogenous agents and transcription regulation. In the present study we demonstrate that full-term pregnancy imprints a specific genomic signature in the breast epithelium of postmenopausal parous control women that is significantly different from women who have developed cancer. This genomic signature induced by pregnancy could help to predict in which women parity is protective.

17-Beta-estradiol induces transformation and tumorigenesis in human breast epithelial cells.

Breast cancer is a malignancy whose dependence on estrogen exposure has long been recognized even though the mechanisms whereby estrogens cause cancer are not clearly understood. This work was performed to determine whether 17beta-estradiol (E2), the predominant circulating ovarian steroid, is carcinogenic in human breast epithelial cells and whether nonreceptor mechanisms are involved in the initiation of breast cancer. For this purpose, the effect of four 24 h alternate periods of 70 nM E2 treatment of the estrogen receptor alpha (ER-alpha) negative MCF-10F cell line on the in vitro expression of neoplastic transformation was evaluated. E2 treatment induced the expression of anchorage-independent growth, loss of ductulogenesis in collagen, invasiveness in Matrigel, and loss of 9p11-13. Only invasive cells that exhibited a 4p15.3-16 deletion were tumorigenic. Tumors were poorly differentiated ER-alpha and progesterone receptor-negative adenocarcinomas that expressed keratins, EMA, and E-cadherin. Tumors and tumor-derived cell lines exhibited loss of chromosome 4, deletions in chromosomes 3p12.3-13, 8p11.1-21, 9p21-qter, and 18q, and gains in 1p, and 5q15-qter. The induction of complete transformation of MCF-10F cells in vitro confirms the carcinogenicity of E2, supporting the concept that this hormone could act as an initiator of breast cancer in women. This model provides a unique system for understanding the genomic changes that intervene for leading normal cells to tumorigenesis and for testing the functional role of specific genomic events taking place during neoplastic transformation.

The genomic signature of breast cancer prevention.

Early pregnancy imprints in the breast permanent genomic changes or a signature that reduces the susceptibility of this organ to cancer. The breast attains its maximum development during pregnancy and lactation. After menopause, the breast regresses in both nulliparous and parous women containing lobular structures designated Lob.1. The Lob 1 found in the breast of nulliparous women and of parous women with breast cancer never went through the process of differentiation, retaining a high concentration of epithelial cells that are targets for carcinogens and therefore susceptible to undergoing neoplastic transformation, these cell are called Stem cells 1, whereas Lob 1 structures found in the breast of early parous postmenopausal women free of mammary pathology, on the other hand, are composed of an epithelial cell population that is refractory to transformation called Stem cells 2. The degree of differentiation acquired through early pregnancy has changed the genomic signature that differentiates the Lob 1 from the early parous women from that of the nulliparous women by shifting the Stem cell 1 to a Stem cell 2, making this the postulated mechanism of protection conferred by early full-term pregnancy. The identification of a putative breast stem cell (Stem cell 1) has reached in the last decade a significant impulse and several markers also reported for other tissues have been found in the mammary epithelial cells of both rodents and humans. The data obtained thus far is supporting the concept that the lifetime protective effect of an early pregnancy against breast cancer is due to the complete differentiation of the mammary gland, which results in the replacement of the Stem cell 1 that is a component of the nulliparous breast epithelium with a new stem cell, called Stem cell 2, which is characterized by a specific genomic signature. The pattern of gene expression of the stem cell 2 could potentially be used as useful intermediate end points for evaluating the degree of mammary gland differentiation and for evaluating preventive agents such as human chorionic gonadotropin.