"Metalloestrogenic" effects of cadmium downstream of G protein-coupled estrogen receptor and mitogen-activated protein kinase pathways in human uterine fibroid cells

A Prospective Ultrasound Study of Whole Blood Metals and Incidence of Uterine Leiomyomata

BACKGROUND

Uterine leiomyomata (UL), hormone-dependent neoplasms, are a major source of gynecologic morbidity. Metals are hypothesized to influence UL risk through endocrine disruption, and their effects may vary by vitamin D status.

OBJECTIVE

We estimated associations of a metal mixture with incident UL, overall and by vitamin D status.

METHODS

We analyzed data from the Study of Environment, Lifestyle and Fibroids, a Detroit-area prospective cohort study of 1,693 black women 23-35 years of age. We measured concentrations of 17 metals/metalloids in whole blood and 25-hydroxyvitamin D [25(OH)D] in serum collected at baseline (2010-2012). Participants underwent ultrasonography at baseline and after 20 months to detect UL. We used Bayesian kernel machine regression to estimate adjusted associations (β ) of the metal mixture with probit of incident UL. We also ran Cox regression models with interaction terms to estimate incidence rate ratios (IRR) by vitamin D status.

RESULTS

Among 1,132 UL-free participants at baseline, 832 (73%) had vitamin D deficiency [25(OH)D < 20  ng / mL ] and 117 (10%) developed UL within 20 months. Increasing all metals from their 50th to 75th percentiles was weakly positively associated with UL overall [β = 0.06 ; 95% credible interval (CrI): - 0.03 , 0.16] and among vitamin D-deficient participants (β = 0.13 ; 95% CrI: 0.01, 0.24), driven by cadmium (overall and vitamin D-deficient) and mercury (vitamin D-deficient only). Increasing cadmium from its 25th to 75th percentile was positively associated with UL overall (β = 0.03 ; 95% CrI: - 0.05 , 0.11) and among vitamin D-deficient participants (β = 0.13 , 95% CrI: 0.02, 0.24). In Cox models, cadmium [IRR = 1.55 ; 95% confidence interval (CI): 1.07, 2.24, per 1-unit increase in standardized concentration] and mercury (IRR = 1.38 ; 95% CI: 0.99, 1.92) were positively associated with UL among vitamin D-deficient participants.

DISCUSSION

The metal mixture was positively associated with incident UL, but the association was weak and imprecise. We observed a stronger association among vitamin D-deficient participants that was driven by cadmium and mercury. https://doi.org/10.1289/EHP15218.

Association between blood heavy metals exposure with uterine fibroids among American women: a cross-sectional analysis from NHANES data

BACKGROUND

Excessive exposure to heavy metals has been linked to various health problems, including organ damage, neurological disorders, and reproductive and developmental abnormalities. However, the relationship between heavy metals exposure and uterine fibroids remains uncertain. To explore this association, we conducted a cross-sectional study among American women.

METHODS

We utilized data from three cycles of the National Health and Nutrition Examination Survey (NHANES, 1999-2006) to evaluate the association between uterine fibroids and blood heavy metal levels, including lead (Pb), cadmium (Cd), and mercury (Hg). Weighted logistic regression, restricted cubic spline (RCS), Bayesian kernel machine regression (BKMR), and subgroup analyse were used to examine the potential relationships between blood heavy metals and uterine fibroids.

RESULTS

Of the 4502 American women studied, 542 (12.04%) had uterine fibroids. Elevated levels of all heavy metals were significantly more common in women with uterine fibroids (P < 0.001). Blood Hg levels were notably associated with uterine fibroid prevalence in the adjusted model (OR = 1.41, 95% CI: 1.06-1.89, p = 0.03). Similar patterns were partly observed for blood Pb and Cd. Age and marital status were significant interaction factors concerning Hg exposure (P for interaction < 0.05). A dose-response relationship with an inflection point at 7µmol/L was identified for Hg, and BKMR models indicated a positive association between mixed heavy metal exposure and uterine fibroid risk.

CONCLUSIONS

Exposure to blood heavy metals, particularly Hg, is significantly associated with an elevated risk of uterine fibroids. Further prospective studies are necessary to confirm these findings.

Mechanism and application of feedback loops formed by mechanotransduction and histone modifications

Mechanical stimulation is the key physical factor in cell environment. Mechanotransduction acts as a fundamental regulator of cell behavior, regulating cell proliferation, differentiation, apoptosis, and exhibiting specific signature alterations during the pathological process. As research continues, the role of epigenetic science in mechanotransduction is attracting attention. However, the molecular mechanism of the synergistic effect between mechanotransduction and epigenetics in physiological and pathological processes has not been clarified. We focus on how histone modifications, as important components of epigenetics, are coordinated with multiple signaling pathways to control cell fate and disease progression. Specifically, we propose that histone modifications can form regulatory feedback loops with signaling pathways, that is, histone modifications can not only serve as downstream regulators of signaling pathways for target gene transcription but also provide feedback to regulate signaling pathways. Mechanotransduction and epigenetic changes could be potential markers and therapeutic targets in clinical practice.

The adverse role of endocrine disrupting chemicals in the reproductive system

Reproductive system diseases pose prominent threats to human physical and mental well-being. Besides being influenced by genetic material regulation and changes in lifestyle, the occurrence of these diseases is closely connected to exposure to harmful substances in the environment. Endocrine disrupting chemicals (EDCs), characterized by hormone-like effects, have a wide range of influences on the reproductive system. EDCs are ubiquitous in the natural environment and are present in a wide range of industrial and everyday products. Currently, thousands of chemicals have been reported to exhibit endocrine effects, and this number is likely to increase as the testing for potential EDCs has not been consistently required, and obtaining data has been limited, partly due to the long latency of many diseases. The ability to avoid exposure to EDCs, especially those of artificially synthesized origin, is increasingly challenging. While EDCs can be divided into persistent and non-persistent depending on their degree of degradation, due to the recent uptick in research studies in this area, we have chosen to focus on the research pertaining to the detrimental effects on reproductive health of exposure to several EDCs that are widely encountered in daily life over the past six years, specifically bisphenol A (BPA), phthalates (PAEs), polychlorinated biphenyls (PCBs), parabens, pesticides, heavy metals, and so on. By focusing on the impact of EDCs on the hypothalamic-pituitary-gonadal (HPG) axis, which leads to the occurrence and development of reproductive system diseases, this review aims to provide new insights into the molecular mechanisms of EDCs' damage to human health and to encourage further in-depth research to clarify the potentially harmful effects of EDC exposure through various other mechanisms. Ultimately, it offers a scientific basis to enhance EDCs risk management, an endeavor of significant scientific and societal importance for safeguarding reproductive health.

FOXM1 promotes neurofibromatosis type 1-associated malignant peripheral nerve sheath tumor progression in a NUF2-dependent manner

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft-tissue sarcomas characterized by poor prognosis and low drug response rates. Traditional chemo/radiotherapies show only mild benefits for patients with MPNSTs, and no targeted therapy is available in the clinic. A better understanding of the molecular background of MPNSTs is critical for the development of effective targeted therapies. Forkhead box M1 (FOXM1) has been implicated in the progression of many human malignancies, though its role in MPNSTs is unclear. In this study, using four Gene Expression Omnibus (GEO) datasets and a tissue microarray, we demonstrated that FOXM1 upregulation was associated with poor prognosis in patients with MPNSTs. FOXM1 overexpression and knockdown regulated the proliferation and colony formation of MPNST cells. Using bioinformatics analysis and luciferase reporter assays, we identified NUF2 as a direct downstream target of FOXM1. Both in vitro and in vivo experiments demonstrated that the induction of MPNST cell proliferation by FOXM1 was dependent on elevated NUF2 expression, as NUF2 knockdown abolished the FOXM1-induced proliferation of MPNST cells. Our study showed that the FOXM1-NUF2 axis mediates human MPNST progression and could be a potential therapeutic target.

A View on Uterine Leiomyoma Genesis through the Prism of Genetic, Epigenetic and Cellular Heterogeneity

Uterine leiomyomas (ULs), frequent benign tumours of the female reproductive tract, are associated with a range of symptoms and significant morbidity. Despite extensive research, there is no consensus on essential points of UL initiation and development. The main reason for this is a pronounced inter- and intratumoral heterogeneity resulting from diverse and complicated mechanisms underlying UL pathobiology. In this review, we comprehensively analyse risk and protective factors for UL development, UL cellular composition, hormonal and paracrine signalling, epigenetic regulation and genetic abnormalities. We conclude the need to carefully update the concept of UL genesis in light of the current data. Staying within the framework of the existing hypotheses, we introduce a possible timeline for UL development and the associated key events—from potential prerequisites to the beginning of UL formation and the onset of driver and passenger changes.

Prolonged Cadmium Exposure Alters Migration Dynamics and Increases Heterogeneity of Human Uterine Fibroid Cells—Insights from Time Lapse Analysis

Cadmium (Cd) is one of the most prevalent environmental heavy metal contaminants and is considered an endocrine disruptor and carcinogen. In women with uterine fibroids, there is a correlation between blood Cd levels and fibroid tumor size. In this study, fibroid cells were exposed to 10 µM CdCl2 for 6 months and a fast-growing Cd-Resistant Leiomyoma culture, termed CR-LM6, was recovered. To characterize the morphological and mechanodynamic features of uterine fibroid cells associated with prolonged Cd exposure, we conducted time lapse imaging using a Zeiss confocal microscope and analyzed data by Imaris and RStudio. Our experiments recorded more than 64,000 trackable nuclear surface objects, with each having multiple parameters such as nuclear size and shape, speed, location, orientation, track length, and track straightness. Quantitative analysis revealed that prolonged Cd exposure significantly altered cell migration behavior, such as increased track length and reduced track straightness. Cd exposure also significantly increased the heterogeneity in nuclear size. Additionally, Cd significantly increased the median and variance of instantaneous speed, indicating that Cd exposure results in higher speed and greater variation in motility. Profiling of mRNA by NanoString analysis and Ingenuity Pathway Analysis (IPA) strongly suggested that the direction of gene expression changes due to Cd exposure enhanced cell movement and invasion. The altered expression of extracellular matrix (ECM) genes such as collagens, matrix metallopeptidases (MMPs), secreted phosphoprotein 1 (SPP1), which are important for migration contact guidance, may be responsible for the greater heterogeneity. The significantly increased heterogeneity of nuclear size, speed, and altered migration patterns may be a prerequisite for fibroid cells to attain characteristics favorable for cancer progression, invasion, and metastasis.