Alteration of Mammary Gland Development and Gene Expression by In Utero Exposure to Cadmium.

Environmental exposure to estrogens and estrogen like contaminants during early development is thought to contribute to the risk of developing breast cancer primarily due to an early onset of puberty; however, exposure during key developing windows may also influence the risk of developing the disease. The goal of this study was to ask whether in utero exposure to the metalloestrogen cadmium alters mammary gland development due to acceleration of puberty onset or to an effect on early development of the mammary gland. The results show that, in addition to advancing the onset of puberty, in utero exposure to the metalloestrogen cadmium altered mammary gland development prior to its effect on puberty onset. In utero exposure resulted in an expansion of the number of mammosphere-forming cells in the neonatal mammary gland and an increase in branching, epithelial cells, and density in the prepubertal mammary gland. In the postpubertal mammary gland, there was a further expansion of the mammary stem/progenitor cell population and overexpression of estrogen receptor-alpha (ERα) that was due to the overexpression and altered regulation of the ERα transcripts derived from exons O and OT in response to estradiol. These results suggest that in utero exposure to cadmium increases stem/progenitor cells, cell density, and expression of estrogen receptor-alpha that may contribute to the risk of developing breast cancer.

Episodic angioedema with eosinophilia (Gleich syndrome) is a multilineage cell cycling disorder.

Episodic angioedema with eosinophilia (Gleich syndrome) is a rare disorder characterized by episodes of angioedema and eosinophilia that occur at monthly intervals and resolve spontaneously without therapy. Despite the striking periodicity of this disorder, its similarity to other cyclic hematopoietic disorders with multilineage involvement has not been assessed. To characterize the involvement of cell lineages in the etiology and pathogenesis of episodic angioedema with eosinophilia, four subjects were evaluated by blood counts and other analyses over the course of 1-2 months. Surface marker expression was assessed on T cells by flow cytometry and clonality by polymerase chain reaction. Intracellular cytokine evaluation, bone marrow and skin biopsies were performed during different parts of the cycle. Cycling of multiple cell lineages, including neutrophils, lymphocytes and eosinophils, was observed in the four subjects with the disorder with a periodicity of 25-35 days. An aberrant CD3(-)CD4(+) T-cell population was detected in all four subjects, and T-cell receptor rearrangement studies showed a clonal pattern in three subjects. A peak of type II cytokines was detected in the serum of subjects prior to the onset of symptoms and eosinophil cycling and corresponded to ex-vivo type II cytokines detected intracellularly in CD3(+)CD4(+)CD154(+) T cells. Although the etiology of episodic angioedema with eosinophilia is not yet known, multiple lineages, including lymphocytes, neutrophils and mast cells, are involved and may be related to disease pathogenesis. Whether these cells act directly or promote eosinophilia and eosinophil activation remains to be elucidated. All subjects gave informed consent and were evaluated under an Institutional Review Board-approved protocol (NCT00001406).

Alteration of mammary gland development and gene expression by in utero exposure to arsenic.

Early life exposure to estrogens and estrogen like contaminants in the environment is thought to contribute to the early onset of puberty and consequently increases the risk of developing breast cancer in the exposed female. The results of this study show that in utero exposure to the metalloestrogen arsenite altered mammary gland development prior to its effect on puberty onset. In the prepubertal gland, in utero exposure resulted in an increase in the number of mammosphere-forming cells and an increase in branching, epithelial cells, and density. In the postpubertal gland, in utero exposure resulted in the overexpression of estrogen receptor-alpha (ERα) that was due to the increased and altered response of the ERα transcripts derived from exons O and OT to estradiol. These results suggest that, in addition to advancing puberty onset, in utero exposure to arsenite alters the pre- and postpubertal development of the mammary gland and possibly, the risk of developing breast cancer.