RESUMEN
BACKGROUND: Estrogen receptor (ER) signaling plays an important role in the development and functional differentiation of the breast and participates in the process of breast cancer. Activated ER can affect various aspects of the cell's behavior, including proliferation, via modulating the expression of many downstream target genes. Phosphorylation is one of the activation pathways of ER. However, the relationship between estrogen receptor phosphorylation sites and breast development and carcinogenesis is not clear. METHODS: Using Crisper-Cas9 gene editing technology, we constructed ER S309A mutant mice. Using carmine staining of the mammary gland of mice at different developmental stages, we examined the breast development of ER S309A mice. Using hematoxylin-eosin (HE) staining of vaginal smears of mice at the same time for 5 consecutive days, we measured the vaginal epithelial keratinocytes. RESULTS: We established ER S309A mutant mice and observed breast defects in ER S309A mice. In addition, we observed decreased reproductive ability, and estrous cycle disorder in ER S309A mice. The number of vaginal epithelial keratino-cytes in the estrous cycle of ER S309A mice was decreased. CONCLUSION: These results suggest that the phosphorylation site of ER at Serine 309 is important for ER function and breast development.
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Mama , Receptor alfa de Estrógeno , Serina , Animales , Femenino , Ratones , Mama/crecimiento & desarrollo , Mama/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/crecimiento & desarrollo , Mutación , Fosforilación , Receptores de Estrógenos/metabolismo , Receptores de Estrógenos/genética , Serina/metabolismo , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismoRESUMEN
Whether trace metals modify breast density, the strongest predictor for breast cancer, during critical developmental stages such as puberty remains understudied. Our study prospectively evaluated the association between trace metals at Tanner breast stage B1 (n = 291) and at stages both B1 and B4 (n = 253) and breast density at 2 years post-menarche among Chilean girls from the Growth and Obesity Cohort Study. Dual-energy x-ray absorptiometry assessed the volume of dense breast tissue (absolute fibroglandular volume [FGV]) and percent breast density (%FGV). Urine trace metals included arsenic, barium, cadmium, cobalt, cesium, copper, magnesium, manganese, molybdenum, nickel, lead, antimony, selenium, tin, thallium, vanadium, and zinc. At B1, a doubling of thallium concentration resulted in 13.69 cm3 increase in absolute FGV (ß: 13.69, 95% confidence interval [CI]: 2.81, 24.52), while a doubling of lead concentration resulted in a 7.76 cm3 decrease in absolute FGV (ß: -7.76, 95%CI: -14.71, -0.73). At B4, a doubling of barium concentration was associated with a 10.06 cm3 increase (ß: 10.06, 95% CI: 1.44, 18.60), copper concentration with a 12.29 cm3 increase (ß: 12.29, 95% CI: 2.78, 21.56), lead concentration with a 9.86 cm3 increase (ß: 9.86, 95% CI: 0.73, 18.98), antimony concentration with a 12.97 cm3 increase (ß: 12.97, 95% CI: 1.98, 23.79) and vanadium concentration with a 13.14 cm3 increase in absolute FGV (ß: 13.14, 95% CI: 2.73, 23.58). Trace metals may affect pubertal breast density at varying developmental stages with implications for increased susceptibility for breast cancer.
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Absorciometría de Fotón , Densidad de la Mama , Oligoelementos , Humanos , Femenino , Chile/epidemiología , Adolescente , Densidad de la Mama/efectos de los fármacos , Oligoelementos/análisis , Oligoelementos/orina , Estudios Prospectivos , Niño , Mama/efectos de los fármacos , Mama/crecimiento & desarrollo , Neoplasias de la Mama/epidemiologíaRESUMEN
INTRODUCTION: Over the decades the trends of early onset of puberty have been observed in children, particularly in girls. Research evidence has reported diet to be among the most important risk factors for puberty onset. This study evaluated the association between dietary behavior and puberty in girls. METHODS: We enrolled 201 girls with the main complaints of breast development as the cases at the Endocrine Department of Nanjing Children's Hospital. The cases were divided into breast development with central priming and breast development without central priming groups and were matched with 223 normal health girls with no breast development (control group). We used the modified Child Eating Behavior Questionnaire (CEBQ) to conduct a face-to-face interview about dietary behavior. Sample t-test or Mann Whitney U test or Chi-square test, the analysis of variance or Kruskal Wallis test, and least significant difference (LSD) were used to compare differences between the groups, Bonferroni was used to correct the p-value, and logistic regression was used to analyze risk factors for puberty onset. RESULTS: A total of 424 girls participated in this study, among them, 136 were cases with breast development with central priming, 65 were cases with breast development without central priming, and 223 were normal health girls with no breast development. Age of the participants ranged from 4.5 to 9.3 years. There were significant differences in food response (p < 0.001), dietary restriction (p < 0.001), frequencies of vegetable intake (χ2 = 8.856, p = 0.012), drinking milk (χ2 = 23.099, p = 0.001), and borderline statistical difference in a total score of unhealthy dietary behavior (p = 0.053) among the cases and controls. However, in the post hoc analysis, these dietary behaviors were significant differences between the girls with breast development with central priming and the control groups. Moreover, girls in the breast development with central priming group had significantly higher bone age (BA), uterine body length, ovarian volume, basal luteinizing hormone (LH), basal follicle-stimulating hormone (FSH), peak LH, peak FSH, estradiol (E2), and free triiodothyronine (FT3) compared to those in the breast development without central priming group. In the multivariate logistic regression, only uterine body length was associated with increased risk of breast development with central priming (OR = 1.516, 95%CI: 1.243-1.850). CONCLUSION: There were significant differences in dietary behaviors among girls with breast development with central priming and normal health girls with no breast development, and uterine body length was associated with an increasing risk of breast development with central priming among girls with breast development.
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Conducta Alimentaria , Pubertad , Humanos , Femenino , Niño , Pubertad/fisiología , Estudios de Casos y Controles , Factores de Riesgo , Preescolar , Dieta , Pubertad Precoz/epidemiología , Pubertad Precoz/etiología , Modelos Logísticos , Mama/crecimiento & desarrolloRESUMEN
The liver kinase B1 (LKB1) controls cellular metabolism and cell polarity across species. We previously established a mechanism for negative regulation of transforming growth factor ß (TGFß) signaling by LKB1. The impact of this mechanism in the context of epithelial polarity and morphogenesis remains unknown. After demonstrating that human mammary tissue expresses robust LKB1 protein levels, whereas invasive breast cancer exhibits significantly reduced LKB1 levels, we focused on mammary morphogenesis studies in three dimensional (3D) acinar organoids. CRISPR/Cas9-introduced loss-of-function mutations of STK11 (LKB1) led to profound defects in the formation of 3D organoids, resulting in amorphous outgrowth and loss of rotation of young organoids embedded in matrigel. This defect was associated with an enhanced signaling by TGFß, including TGFß auto-induction and induction of transcription factors that mediate epithelial-mesenchymal transition (EMT). Protein marker analysis confirmed a more efficient EMT response to TGFß signaling in LKB1 knockout cells. Accordingly, chemical inhibition of the TGFß type I receptor kinase largely restored the morphogenetic defect of LKB1 knockout cells. Similarly, chemical inhibition of the bone morphogenetic protein pathway or the TANK-binding kinase 1, or genetic silencing of the EMT factor SNAI1, partially restored the LKB1 knockout defect. Thus, LKB1 sustains mammary epithelial morphogenesis by limiting pathways that promote EMT. The observed downregulation of LKB1 expression in breast cancer is therefore predicted to associate with enhanced EMT induced by SNAI1 and TGFß family members.
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Mama , Transición Epitelial-Mesenquimal , Morfogénesis , Organoides , Femenino , Humanos , Células Epiteliales/metabolismo , Hígado/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Línea Celular , Mama/citología , Mama/crecimiento & desarrolloRESUMEN
Stressful environments have been associated with earlier menarche. We hypothesized that anxiety, and possibly other internalizing symptoms, are also associated with earlier puberty in girls. The Lessons in Epidemiology and Genetics of Adult Cancer From Youth (LEGACY) Girls Study (2011-2016) included 1,040 girls aged 6-13 years at recruitment whose growth and development were assessed every 6 months. Prepubertal maternal reports of daughter's internalizing symptoms were available for breast onset (n = 447), pubic hair onset (n = 456), and menarche (n = 681). Using Cox proportional hazard regression, we estimated prospective hazard ratios and 95% confidence intervals for the relationship between 1 standard deviation of the percentiles of prepubertal anxiety, depression, and somatization symptoms and the timing of each pubertal outcome. Multivariable models included age, race/ethnicity, study center, maternal education, body mass index percentile, and family history of breast cancer. Additional models included maternal self-reported anxiety. A 1-standard deviation increase in maternally reported anxiety in girls at baseline was associated with earlier subsequent onset of breast (hazard ratio (HR) = 1.22, 95% confidence interval (CI): 1.09, 1.36) and pubic hair (HR = 1.15, 95% CI: 1.01, 1.30) development, but not menarche (HR = 0.94, 95% CI: 0.83, 1.07). The association of anxiety with earlier breast development persisted after adjustment for maternal anxiety. Increased anxiety in young girls may indicate risk for earlier pubertal onset.
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Mama/crecimiento & desarrollo , Mecanismos de Defensa , Menarquia/fisiología , Estrés Psicológico/epidemiología , Estrés Psicológico/fisiopatología , Adolescente , Factores de Edad , Índice de Masa Corporal , Niño , Femenino , Humanos , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Pubertad , Grupos Raciales , Factores SocioeconómicosRESUMEN
BACKGROUND: Systemic inflammation may play a role in shaping breast composition, one of the strongest risk factors for breast cancer. Pubertal development presents a critical window of breast tissue susceptibility to exogenous and endogenous factors, including pro-inflammatory markers. However, little is known about the role of systemic inflammation on adolescent breast composition and pubertal development among girls. METHODS: We investigated associations between circulating levels of inflammatory markers (e.g., interleukin-6 (IL-6), tumor necrosis factor receptor 2 (TNFR2), and C-reactive protein (CRP)) at Tanner stages 2 and 4 and breast composition at Tanner stage 4 in a cohort of 397 adolescent girls in Santiago, Chile (Growth and Obesity Cohort Study, 2006-2018). Multivariable linear models were used to examine the association between breast composition and each inflammatory marker, stratifying by Tanner stage at inflammatory marker measurement. Accelerated failure time models were used to evaluate the association between inflammatory markers concentrations at each Tanner stage and time to menarche. RESULTS: In age-adjusted linear regression models, a doubling of TNFR2 at Tanner 2 was associated with a 26% (95% CI 7-48%) increase in total breast volume at Tanner 4 and a 22% (95% CI 10-32%) decrease of fibroglandular volume at Tanner 4. In multivariable models further adjusted for body fatness and other covariates, these associations were attenuated to the null. The time to menarche was 3% (95% CI 1-5%) shorter among those in the highest quartile of IL-6 at Tanner 2 relative to those in the lowest quartile in fully adjusted models. Compared to those in the lowest quartile of CRP at Tanner 4, those in the highest quartile experienced 2% (95% CI 0-3%) longer time to menarche in multivariable models. CONCLUSIONS: Systemic inflammation during puberty was not associated with breast volume or breast density at the conclusion of breast development among pubertal girls after adjusting for body fatness; however, these circulating inflammation biomarkers, specifically CRP and IL-6, may affect the timing of menarche onset.
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Biomarcadores/sangre , Densidad de la Mama , Mama/inmunología , Inflamación/inmunología , Menarquia , Pubertad , Mama/crecimiento & desarrollo , Mama/metabolismo , Proteína C-Reactiva/metabolismo , Niño , Estudios de Cohortes , Femenino , Humanos , Inflamación/metabolismo , Interleucina-6/metabolismo , Receptores Tipo II del Factor de Necrosis Tumoral/metabolismo , Factores de Riesgo , Maduración SexualRESUMEN
BACKGROUND: Earlier age at menarche is an established risk factor for breast cancer. While age at menarche has been fairly stable over the past half-century, age at breast development (thelarche) has continued to decrease. Recently, earlier age at thelarche and a longer time between thelarche and menarche (pubertal tempo) were shown to be associated with increased breast cancer risk. Our objective was to examine how breast cancer risk was associated with pubertal timing and tempo in a prospective US cohort. METHODS: Women ages 35-74 years without a history of breast cancer, but who had a sister previously diagnosed with breast cancer, were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported their ages at thelarche and menarche. Pubertal tempo was age at menarche minus age at thelarche. We estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for each pubertal milestone and risk of breast cancer (invasive or ductal carcinoma in situ) using Cox proportional hazards regression. We examined whether associations between age at thelarche and breast cancer risk were modified by birth cohort, race/ethnicity, weight at age 10, and extent of breast cancer family history, as characterized by a Bayesian score based on first-degree family structure. RESULTS: During follow-up (mean = 9.3 years), 3295 eligible women were diagnosed with breast cancer. Early ages at thelarche (HR = 1.23, 95% CI 1.03-1.46 for < 10 vs. 12-13 years) and menarche (HR = 1.10, 95% CI 1.01-1.20 for < 12 vs. 12-13 years) were positively associated with breast cancer risk. Pubertal tempo was not associated with breast cancer risk (HR = 0.99, 95% CI 0.97-1.02 per 1-year longer tempo). When considering early thelarche (< 10 years) and early menarche (< 12 years) jointly, women with both had a 30% greater risk of breast cancer compared with women with neither risk factor (95% CI 1.07-1.57). The association between age at thelarche and breast cancer risk did not significantly vary by birth cohort, race/ethnicity, childhood weight, or Bayesian family history score. CONCLUSIONS: Earlier ages at thelarche and menarche may enhance susceptibility to breast carcinogenesis. Age at thelarche is an important risk factor to consider given secular trends towards earlier development.
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Peso Corporal , Neoplasias de la Mama/epidemiología , Mama/crecimiento & desarrollo , Menarquia , Pubertad , Hermanos , Factores de Tiempo , Adolescente , Adulto , Anciano , Teorema de Bayes , Índice de Masa Corporal , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Niño , Estudios de Cohortes , Femenino , Humanos , Incidencia , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: Obesity has been associated with earlier thelarche, whereas other predictors for it remain unclear. METHODS: We studied child-related and parental predictors for earlier thelarche in 195 girls aged 6-8 years followed up for 2 years. A physician evaluated breast development by inspection and palpation. Body fat percentage (BF%) was measured by dual-energy X-ray absorptiometry, diet by food records, and physical activity and sedentary time by body movement and heart rate monitors. Parental education, smoking, and alcohol consumption and household income were assessed by questionnaires. Gestational age, birth weight, and maternal prepregnancy BMI were obtained from hospital registers. Predictors for thelarche were examined using logistic regression analysis adjusted for age and follow-up time. RESULTS: The incidence of thelarche during 2 years increased by 11% (OR 1.11, CI 1.06-1.17, p < 0.001) for 1 unit increase in baseline BF%. Girls with a smoking parent had a 2.64 (95% CI 1.21-5.77, p = 0.015) times higher incidence of thelarche than other girls. The associations of lower parental education and higher maternal prepregnancy BMI with the higher incidence of thelarche were largely explained by BF%. Other possible predictors were not associated with thelarche. CONCLUSIONS: Higher BF% and exposure to tobacco smoke are independent predictors for earlier thelarche.
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Tejido Adiposo , Índice de Masa Corporal , Mama/crecimiento & desarrollo , Obesidad Infantil/complicaciones , Pubertad Precoz/complicaciones , Contaminación por Humo de Tabaco/efectos adversos , Absorciometría de Fotón , Adiposidad , Consumo de Bebidas Alcohólicas , Peso al Nacer , Niño , Dieta , Escolaridad , Familia , Conducta Alimentaria , Femenino , Finlandia , Frecuencia Cardíaca , Humanos , Incidencia , Movimiento , Padres , Fumar , Clase SocialRESUMEN
OBJECTIVE: To examine adherence to a Mediterranean-like diet at age 9-10 years in relation to onset of breast development (thelarche) and first menstruation (menarche). DESIGN: We evaluated the associations of adherence to a Mediterranean-like diet (measured by an adapted Mediterranean-like Diet Score, range 0-9) with thelarche at baseline, age at thelarche and time to menarche. Data were collected at baseline during a clinic visit, complemented with a mailed questionnaire and three 24 hour telephone dietary recalls, followed by annual follow-up questionnaires. Multivariable Poisson regression, linear regression and Cox proportional hazards regression were used to evaluate timing of pubertal development in relation to diet adherence. SETTING: New Jersey, USA. PARTICIPANTS: Girls aged 9 or 10 years at baseline (2006-2014, n 202). RESULTS: High Mediterranean-like diet adherence (score 6-9) was associated with a lower prevalence of thelarche at baseline compared with low adherence (score 0-3; prevalence ratio = 0·65, 95 % CI 0·48, 0·90). This may have been driven by consumption of fish and non-fat/low-fat dairy. Our models also suggested a later age at thelarche with higher Mediterranean-like diet adherence. Girls with higher Mediterranean-like diet adherence had significantly longer time to menarche (hazard ratio = 0·45, 95 % CI 0·28, 0·71 for high v. low adherence). Further analysis suggested this may have been driven by vegetable and non-fat/low-fat dairy consumption. CONCLUSIONS: Consuming a Mediterranean-like diet may be associated with older age at thelarche and menarche. Further research is necessary to confirm our findings in other US paediatric populations and elucidate the mechanism through which Mediterranean-like diet may influence puberty timing.
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Factores de Edad , Mama/crecimiento & desarrollo , Dieta Mediterránea/estadística & datos numéricos , Menarquia , Niño , Dieta Mediterránea/efectos adversos , Femenino , Humanos , Modelos Lineales , Distribución de Poisson , Modelos de Riesgos Proporcionales , Pubertad Tardía/etiologíaRESUMEN
Organoid cultures in 3D matrices are relevant models to mimic the complex in vivo environment that supports cell physiological and pathological behaviors. For instance, 3D epithelial organoids recapitulate numerous features of glandular tissues including the development of fully differentiated acini that maintain apico-basal polarity with hollow lumen. Effective genetic engineering in organoids would bring new insights in organogenesis and carcinogenesis. However, direct 3D transfection on already formed organoids remains challenging. One limitation is that organoids are embedded in extracellular matrix and grow into compact structures that hinder transfection using traditional techniques. To address this issue, we developed an innovative approach for transgene expression in 3D organoids by combining single-cell encapsulation in Matrigel microbeads using a microfluidic device and electroporation. We demonstrate that direct electroporation of encapsulated organoids reaches up to 80% of transfection efficiency. Using this technique and a morphological read-out that recapitulate the different stages of tumor development, we further validate the role of p63 and PTEN as key genes in acinar development in breast and prostate tissues. We believe that the combination of controlled organoid generation and efficient 3D transfection developed here opens new perspectives for flow-based high-throughput genetic screening and functional genomic applications.
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Colágeno , Laminina , Organoides/citología , Proteoglicanos , Transfección/métodos , Mama/crecimiento & desarrollo , Línea Celular , Línea Celular Tumoral , Combinación de Medicamentos , Electroporación , Femenino , Humanos , Dispositivos Laboratorio en un Chip , Masculino , Microesferas , Fosfohidrolasa PTEN/genética , Próstata/crecimiento & desarrollo , Interferencia de ARN , ARN Interferente Pequeño , Esferoides Celulares/citología , Factores de Transcripción/genética , Proteínas Supresoras de Tumor/genéticaRESUMEN
Onset of puberty, as defined by breast stage 2, appears to be starting at younger ages since the 1940s. There is an ongoing controversy regarding what is normative, as well as what is normal, and the evaluation that is deemed necessary for girls maturing before 8 years of age. There are potential implications of earlier pubertal timing, including psychosocial consequences during adolescence, as well as longer term risks, such as breast cancer and cardiometabolic risks. There are additional consequences derived from slower pubertal tempo, for age of menarche has not decreased as much as age of breast development; these include longer interval between sexual initiation and intentional childbearing, as well as a broadened window of susceptibility to endocrine-related cancers.
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Desarrollo del Adolescente/fisiología , Mama/crecimiento & desarrollo , Menarquia , Pubertad Precoz , Pubertad , Adolescente , Índice de Masa Corporal , Mama/patología , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/epidemiología , Factores de Riesgo Cardiometabólico , Niño , Femenino , Humanos , Menarquia/fisiología , Menarquia/psicología , Psicología , Pubertad/fisiología , Pubertad/psicología , Pubertad Precoz/diagnóstico , Pubertad Precoz/epidemiología , Pubertad Precoz/fisiopatología , Maduración Sexual/fisiologíaRESUMEN
Adipose tissue is a complex endocrine organ, with a role in obesity and cancer. Adipose tissue is generally linked to excessive body fat, and it is well known that the female breast is rich in adipose tissue. Hence, one can wonder: what is the role of adipose tissue in the breast and why is it required? Adipose tissue as an organ consists of adipocytes, an extracellular matrix (ECM) and immune cells, with a significant role in the dynamics of breast changes throughout the life span of a female breast from puberty, pregnancy, lactation and involution. In this review, we will discuss the importance of breast adipose tissue in breast development and its involvement in breast changes happening during pregnancy, lactation and involution. We will focus on understanding the biology of breast adipose tissue, with an overview on its involvement in the various steps of breast cancer development and progression. The interaction between the breast adipose tissue surrounding cancer cells and vice-versa modifies the tumor microenvironment in favor of cancer. Understanding this mutual interaction and the role of breast adipose tissue in the tumor microenvironment could potentially raise the possibility of overcoming breast adipose tissue mediated resistance to therapies and finding novel candidates to target breast cancer.
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Tejido Adiposo/patología , Neoplasias de la Mama/patología , Mama/patología , Mama/crecimiento & desarrollo , Neoplasias de la Mama/genética , Neoplasias de la Mama/terapia , Comunicación Celular , Femenino , Humanos , Lactancia , Embarazo , Factores de RiesgoRESUMEN
Puberty is the process of physical changes between childhood and adulthood during which adolescents reach sexual maturity and become capable of reproduction. It is considered one of the main temporal windows of susceptibility for the influence of the endocrine-disrupting chemicals (EDCs). EDCs may act as single chemical agents or as chemical mixtures; they can be pubertal influencers, accelerating and anticipating the processing of maturation of secondary sexual characteristics. Moreover, recent studies have started to point out how exposure to EDCs during puberty may predispose to breast cancer later in life. In fact, the estrogen-mimicking endocrine disruptors (EEDs) may influence breast tissue development during puberty in two main ways: the first is the action on the proliferation of the breast stromal cells, the second concerns epigenetic mechanisms. The aim of this mini-review was to better highlight what is new and what is not completely known regarding the role of EDCs during puberty.
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Neoplasias de la Mama , Mama , Disruptores Endocrinos/toxicidad , Epigénesis Genética/efectos de los fármacos , Pubertad/metabolismo , Adolescente , Adulto , Animales , Mama/crecimiento & desarrollo , Mama/metabolismo , Mama/patología , Neoplasias de la Mama/inducido químicamente , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Niño , Femenino , HumanosRESUMEN
BACKGROUND: Earlier age at onset of pubertal events and longer intervals between them (tempo) have been associated with increased breast cancer risk. It is unknown whether the timing and tempo of puberty are associated with adult breast density, which could mediate the increased risk. METHODS: From 1988 to 1997, girls participating in the Dietary Intervention Study in Children (DISC) were clinically assessed annually between ages 8 and 17 years for Tanner stages of breast development (thelarche) and pubic hair (pubarche), and onset of menses (menarche) was self-reported. In 2006-2008, 182 participants then aged 25-29 years had their percent dense breast volume (%DBV) measured by magnetic resonance imaging. Multivariable, linear mixed-effects regression models adjusted for reproductive factors, demographics, and body size were used to evaluate associations of age and tempo of puberty events with %DBV. RESULTS: The mean (standard deviation) and range of %DBV were 27.6 (20.5) and 0.2-86.1. Age at thelarche was negatively associated with %DBV (p trend = 0.04), while pubertal tempo between thelarche and menarche was positively associated with %DBV (p trend = 0.007). %DBV was 40% higher in women whose thelarche-to-menarche tempo was 2.9 years or longer (geometric mean (95%CI) = 21.8% (18.2-26.2%)) compared to women whose thelarche-to-menarche tempo was less than 1.6 years (geometric mean (95%CI) = 15.6% (13.9-17.5%)). CONCLUSIONS: Our results suggest that a slower pubertal tempo, i.e., greater number of months between thelarche and menarche, is associated with higher percent breast density in young women. Future research should examine whether breast density mediates the association between slower tempo and increased breast cancer risk.
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Densidad de la Mama , Mama/crecimiento & desarrollo , Menarquia/fisiología , Pubertad/fisiología , Maduración Sexual/fisiología , Adolescente , Adulto , Índice de Masa Corporal , Tamaño Corporal/fisiología , Mama/diagnóstico por imagen , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/fisiopatología , Niño , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Estudios Prospectivos , Factores de Riesgo , Factores de TiempoRESUMEN
BACKGROUND: Girls who are overweight/obese (OB) develop breast tissue but do not undergo menarche (the first menstrual period) significantly earlier than girls of normal weight (NW). It has been proposed that estrogen synthesized by adipose tissue may be contributory, yet OB do not have higher serum estrogen levels than NW matched on breast stage. We hypothesized that estrogen synthesized locally, in mammary fat, may contribute to breast development. This hypothesis would predict that breast development would be more advanced than other estrogen-sensitive tissues as a function of obesity and body fat. METHODS: Eighty premenarchal girls (26 OB, 54 NW), aged 8.2-14.7 years, underwent dual-energy x-ray absorptiometry to calculate percent body fat (%BF), Tanner staging of the breast, breast ultrasound for morphological staging, trans-abdominal pelvic ultrasound, hand x-ray (bone age, BA), a blood test for reproductive hormones, and urine collection to determine the vaginal maturation index (VMI), an index of estrogen exposure in urogenital epithelial cells. RESULTS: When controlling for breast morphological stage determined by ultrasound, %BF was not associated with serum estrogen or gonadotropin (LH and FSH) levels or with indices of systemic estrogen action (uterine volume, endometrial thickness, BA advancement, and VMI). Tanner breast stage did not correlate with breast morphological stage and led to misclassification of chest fatty tissue as breast tissue in some OB. CONCLUSIONS: These studies do not support the hypothesis that estrogen derived from total body fat or local (mammary) fat contributes to breast development in OB girls.
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Tejido Adiposo/metabolismo , Mama/metabolismo , Desarrollo Infantil/fisiología , Estrógenos/metabolismo , Sobrepeso/metabolismo , Maduración Sexual/fisiología , Absorciometría de Fotón , Tejido Adiposo/crecimiento & desarrollo , Adolescente , Mama/crecimiento & desarrollo , Niño , Femenino , Encuestas Epidemiológicas , Humanos , Menarquia , North Carolina/epidemiología , Sobrepeso/epidemiología , Vagina/citologíaRESUMEN
STUDY QUESTION: What are the levels of breast development and satisfaction in women with a Disorder/Difference of Sex Development (DSD)? SUMMARY ANSWER: Compared with normative data, women with DSD reached lower Tanner stages and reported less breast satisfaction. WHAT IS KNOWN ALREADY: Women with DSD may have chromosomal and hormonal variations that can impact typical breast development. While much emphasis is placed on genital development in this group, little is known about breast development, satisfaction and their association. STUDY DESIGN, SIZE, DURATION: Data collection was part of the cross-sectional European multicenter dsd-LIFE study. Fourteen recruiting sites included 1040 participants between February 2014 and September 2015. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 695 female-identifying participants were included (Turner n = 332, 46,XY DSD n = 141 and congenital adrenal hyperplasia n = 222), with a median age of 28 years. Clinical (i.e. history of hormone and surgical treatments, Tanner breast examination) and patient-reported (i.e. breast satisfaction, relationship status, sexual satisfaction and experienced femininity) data was collected by independent trained research staff. The relationship between breast development, satisfaction and femininity was assessed. Control data on breast development and satisfaction in women without DSD was retrieved from the literature. MAIN RESULTS AND THE ROLE OF CHANCE: Of the 695 participants, 61% had received estrogen replacement and 51% puberty induction therapy, whereas 2% had received breast augmentation surgery. Approximately 65% of participants had reached Tanner breast stage 5, which is substantially less than the general population (90%). Breast satisfaction was lower than normative data as well (P < 0.001, Cohen's d = 0.45). Breast size and breast satisfaction were associated with feelings of femininity. LIMITATIONS, REASONS FOR CAUTION: Limitations include the sample representativeness (e.g. regarding the clinical heterogeneity) and the limited in-depth knowledge on (prior) hormonal regimens. Furthermore, no (matched) control data was collected as part of this study. WIDER IMPLICATIONS OF THE FINDINGS: In order to support the psychosexual well-being of women with DSD, enhancing breast development by sufficient hormone replacement and possible augmentation surgery is advocated. The scope of DSD management should be beyond genital development only and consider breasts as well. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by the European Union Seventh Framework Program (FP7/2007-2013) under grant agreement no. 305 373. There are no competing interests. TRIAL REGISTRATION NUMBER: German Clinical Trials Register: Registration identification number: DRKS00006072.
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Mama/crecimiento & desarrollo , Trastornos del Desarrollo Sexual/psicología , Adulto , Estudios Transversales , Femenino , Humanos , Mamoplastia , Adulto JovenRESUMEN
STUDY QUESTION: Does the phenotype of women with normosmic congenital hypogonadotrophic hypogonadism (nCHH) and pituitary resistance to GnRH caused by biallelic mutations in the GnRH receptor (GNRHR) (nCHH/bi-GNRHR) differ from that of women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Women with nCHH/bi-GNRHR have variable pubertal development but nearly all have primary amenorrhea and an exaggerated LH response to GnRH stimulation, similar to that seen in women with PCOS. WHAT IS KNOWN ALREADY: Women with nCHH/bi-GNRHR are very rare and their phenotype at diagnosis is not always adequately documented. The results of gonadotrophin stimulation by acute GnRH challenge test and ovarian features have not been directly compared between these patients and women with PCOS. STUDY DESIGN, SIZE, DURATION: We describe the phenotypic spectrum at nCHH/bi-GNRHR diagnosis in a series of 12 women. Their reproductive characteristics and acute responses to GnRH were compared to those of 70 women with PCOS. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients and controls (healthy female volunteers aged over 18 years) were enrolled in a single French referral centre. Evaluation included clinical and hormonal studies, pelvic ultrasonography and GnRH challenge test. We also functionally characterized two missense GNRHR mutations found in two new consanguineous families. MAIN RESULTS AND THE ROLE OF CHANCE: Breast development was highly variable at nCHH/bi-GNRHR diagnosis, but only one patient had undeveloped breasts. Primary amenorrhea was present in all but two cases. In untreated nCHH/bi-GNRHR patients, uterine height (UH) correlated (P = 0.01) with the circulating estradiol level and was shorter than in 23 nulliparous post-pubertal age-matched controls (P < 0.0001) and than in 15 teenagers with PCOS under 20-years-old (P < 0.0001) in which PCOS was revealed by primary amenorrhea or primary-secondary amenorrhea. Unexpectedly, the stimulated LH peak response in nCHH/bi-GNRHR patients was variable, and often normal or exaggerated. Interestingly, the LH peak response was similar to that seen in the PCOS patients, but the latter women had significantly larger mean ovarian volume (P < 0.001) and uterine length (P < 0.001) and higher mean estradiol (P < 0.001), anti-Müllerian hormone (AMH) (P = 0.02) and inhibin-B (P < 0.001) levels. In the two new consaguineous families, the affected nCHH/bi-GNRHR women carried the T269M or Y290F GNRHR missense mutation in the homozygous state. In vitro analysis of GnRHR showed complete or partial loss-of-function of the T269M and Y290F mutants compared to their wildtype counterpart. LIMITATIONS, REASONS FOR CAUTION: The number of nCHH/bi-GNRHR patients reported here is small. As this disorder is very rare, an international study would be necessary to recruit a larger cohort and consolidate the phenotypic spectrum observed here. WIDER IMPLICATIONS OF THE FINDINGS: In teenagers and young women with primary amenorrhea, significant breast and uterine development does not rule out CHH caused by biallelic GNRHR mutations. In rare patients with PCOS presenting with primary amenorrhea and a mild phenotype, the similar exaggerated pituitary LH responses to GnRH in PCOS and nCHH/bi-GNRHR patients could lead to diagnostic errors. This challenge test should therefore not be recommended. As indicated by consensus and guidelines, careful analysis of clinical presentation and measurements of testosterone circulating levels remain the basis of PCOS diagnosis. Also, analysis of ovarian volume, UH and of inhibin-B, AMH, estradiol and androgen circulating levels could help to distinguish between mild PCOS and nCHH/bi-GNRHR. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the French National Research Agency (ANR) grant ANR-09-GENO-017 KALGENOPATH, France; and by the Italian Ministry of Education, University and Research (MIUR) grant PRIN 2012227FLF_004, Italy. The authors declare no conflict of interest.
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Amenorrea/fisiopatología , Hipogonadismo/fisiopatología , Fenotipo , Síndrome del Ovario Poliquístico/fisiopatología , Receptores LHRH/genética , Adolescente , Adulto , Amenorrea/etiología , Mama/crecimiento & desarrollo , Diagnóstico Diferencial , Femenino , Humanos , Hipogonadismo/complicaciones , Hipogonadismo/diagnóstico , Hipogonadismo/genética , Mutación , Síndrome del Ovario Poliquístico/complicaciones , Síndrome del Ovario Poliquístico/diagnóstico , Reproducción/fisiología , Útero/crecimiento & desarrollo , Adulto JovenRESUMEN
BACKGROUND: Further knowledge about the pubertal development mode of girls with Turner syndrome (TS) who have undergone hormone replacement therapy (HRT) is beneficial to the proposal of an optimal HRT regimen. This study examined the pubertal development mode of girls with TS who underwent HRT and evaluated the characteristics of optimal sex induction therapy in girls with TS. METHOD: We conducted a retrospective, longitudinal study over the past two decades at The First Affiliated Hospital, Sun Yat-sen University. PATIENTS: Seventy-one patients with TS and two groups of normal Chinese girls. RESULTS: The total investigation time was 3.00 (2.00, 4.66) years. The interval of each stage was significantly longer (P < 0.001) in the girls with TS than that in the normal Chinese girls, except for B2-3 (P = 0.011). The uterine volumes of the girls with TS in stages B2 and 3 were greater than those of the control group (P = 0.046), whereas the uterine volume of the control group was inversely greater than that of the TS group among those who reached stages B4 and 5 (P = 0.034). During HRT, the uterine volume grew significantly from all previous stages except for breast stage 5 (B3 vs.2: Z = - 2.031; P = 0.042; B4 vs. 3: Z = - 2.273; P = 0.023; B5 vs. 4: Z = - 1.368; P = 0.171). The paired data of 27 girls with TS showed that the uterine volume (17.93 ± 9.31 ml vs. 13.75 ± 6.67 ml) and width (2.54 ± 0.66 cm vs. 2.22 ± 0.36 cm) increased significantly during artificial cycles compared with before artificial cycles (t = - 2.79 and - 2.51, P = 0.01 and 0.018). CONCLUSION: HRT led to normal breast development in girls with TS; half of the girls with TS in our study reached Tanner stage B5, although the uterus ultimately developed suboptimally. The girls' breasts and uteruses grew quickly at the beginning of HRT (stages B2-4). An optimal HRT regimen for girls with TS may specifically focus on Tanner stages B2-4 and artificial cycles.
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Mama/crecimiento & desarrollo , Terapia de Reemplazo de Hormonas , Maduración Sexual/efectos de los fármacos , Síndrome de Turner/tratamiento farmacológico , Mama/efectos de los fármacos , China , Femenino , Humanos , Estudios Longitudinales , Análisis Multivariante , Estudios RetrospectivosRESUMEN
PURPOSE OF REVIEW: This article will provide an overview on female breast development and focus on common abnormalities of growth, the emerging role of breast self-awareness, and discuss trends in the evaluation and treatment of the breast masses and disorders most often encountered in the female adolescent population. RECENT FINDINGS: Although the embryology of breast development is unchanged, data are emerging on the role of environmental factors on the timing of puberty and thelarche. As breast development occurs, the role of breast self-awareness is also a new trend that allows teens to be cognizant of changes in their own breast and to become more comfortable with their own anatomy. Finally, when breast treatments are needed or desired, the timing of breast treatments is a subject that must be individualized. SUMMARY: There are numerous conditions that can result from disruption of normal breast development. These resultant breast disorders are generally benign but can still cause emotional distress to both the patient and family. It is thus imperative that healthcare providers be educated on breast development, the common breast masses that occur in the adolescent population and be prepared to discuss breast self-awareness and shared decision-making in this population.
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Enfermedades de la Mama/fisiopatología , Mama/crecimiento & desarrollo , Adolescente , Mama/embriología , Enfermedades de la Mama/diagnóstico , Enfermedades de la Mama/terapia , Femenino , Humanos , Menarquia/fisiologíaRESUMEN
BACKGROUND: Genetically selected modern broiler chickens have acquired outstanding production efficiency through rapid growth and improved feed efficiency compared to unselected chicken breeds. Recently, we analyzed the transcriptome of breast muscle tissues obtained from modern pedigree male (PeM) broilers (rapid growth and higher efficiency) and foundational Barred Plymouth Rock (BPR) chickens (slow growth and poorer efficiency). This study was designed to investigate microRNAs that play role in rapid growth of the breast muscles in modern broiler chickens. RESULTS: In this study, differential abundance of microRNA (miRNA) was analyzed in breast muscle of PeM and BPR chickens and the results were integrated with differentially expressed (DE) mRNA in the same tissues. A total of 994 miRNA were identified in PeM and BPR chicken lines from the initial analysis of small RNA sequencing data. After filtering and statistical analyses, the results showed miR-2131-5p, miR-221-5p, miR-126-3p, miR-146b-5p, miR-10a-5p, let-7b, miR-125b-5p, and miR-146c-5p up-regulated whereas miR-206 down-regulated in PeM compared to BPR breast muscle. Based on inhibitory regulations of miRNAs on the mRNA abundance, our computational analysis using miRDB, an online software, predicated that 118 down-regulated mRNAs may be targeted by the up-regulated miRNAs, while 35 up-regulated mRNAs appear to be due to a down-regulated miRNA (i.e., miR-206). Functional network analyses of target genes of DE miRNAs showed their involvement in calcium signaling, axonal guidance signaling, and NRF2-mediated oxidative stress response pathways suggesting their involvement in breast muscle growth in chickens. CONCLUSION: From the integrated analyses of differentially expressed miRNA-mRNA data, we were able to identify breast muscle specific miRNAs and their target genes whose concerted actions can contribute to rapid growth and higher feed efficiency in modern broiler chickens. This study provides foundation data for elucidating molecular mechanisms that govern muscle growth in chickens.