The publisher's final edited version of this article is available at J Clin Endocrinol Metab See other articles in PMC that cite the published article. Abstract Context The P enzyme aromatase CYP19 plays a crucial role in the endocrine and paracrine biosynthesis of estrogens from androgens in many diverse estrogen-responsive tissues.
Complete aromatase deficiency has been reported in a small number of 46,XX girls with genital ambiguity and absent pubertal development, but it is unknown whether breast cancer hormonal or anti-estrogen therapy phenotypes exist.
Objective The objective of the study was to determine whether variant forms of aromatase insufficiency can occur in humans. Patients Four patients 46,XX from three kindred with variable degrees of androgenization and pubertal failure. Methods Mutational analysis of CYP19 and assay of enzyme activity.
Updates in the hormonal treatment of breast cancer
Results Aromatase insufficiency resulting in genital ambiguity at birth, but with variable breast development at puberty B2-B4occurred in 46,XX patients from two kindred who harbored point mutations or single codon deletions RC, Fdel. Absent puberty with minimal androgenization at birth was found in one girl with a deletion involving exon5 of CYP19 exon5delwhich would be predicted to lead to an in-frame deletion of 59 amino acids from the enzyme. Functional studies revealed low residual aromatase activity in the cases where breast development occurred.
Low residual aromatase activity may be sufficient for breast and uterine development to occur at puberty, despite significant androgenization in utero.
Breast Cancer: Prognosis, Treatment, and Prevention
Such phenotypic variability may be influenced further by modifying factors, such as non-classic pathways of estrogen synthesis, variability in co-regulators, or differences in androgen responsiveness. Aromatase has important biological effects at different stages of development.
In addition, aromatase mediates uterine growth and bone maturation during adolescence, and influences bone mineralization, lipid metabolism and cardiovascular risk through into adult life 13. Although targeted breast cancer hormonal or anti-estrogen therapy of the gene encoding aromatase Cyp19 in mice is providing fascinating insight into the role of this enzyme in endocrine function, metabolism, cardiovascular function, and fertility 4 - 7our understanding of the role of aromatase in human biology has been furthered by several individual case reports of patients with complete aromatase deficiency OMIM: Maternal virilization during pregnancy occurs with breast cancer hormonal or anti-estrogen therapy of both sexes, following the transplacental passage of fetal androgen precursors into the maternal circulation due to a lack of fetal placental aromatase action.
Furthermore, polymorphic variability within the aromatase CYP19 locus has been reported in association with variations in bone mineral density and fracture risk in both sexes 21 - 23hyperandrogenism in younger females 24and survival in patients breast cancer hormonal or anti-estrogen therapy metastatic prostate cancer 25suggesting an important modulatory role for this enzyme in endocrine and breast cancer hormonal or anti-estrogen therapy function within the wider population.
Variable phenotypes associated with aromatase (CYP19) insufficiency in humans
Despite the potential deleterious consequences of aromatase depletion, aromatase inhibitors are emerging as important pharmacological strategies for treating growth disorders 26endometriosis 27and breast cancer 28 - Thus, the identification and characterization of patients with aromatase insufficiency provides useful structural and functional breast cancer hormonal or anti-estrogen therapy about the role of this enzyme in humans. Here we report the clinical, biochemical and genetic features of variable aromatase insufficiency in a series of four 46,XX patients from three families with point mutations or deletions within the CYP19 gene.
Methods DNA sequence analysis After obtaining Institutional Review Board approval and informed consent from the patients and parents, DNA was extracted from patients' blood leukocytes or saliva using standard methods. Microdeletion detection Following an inability to PCR-amplify exon 5 of CYP19 in subject III:2 using different primers and conditions 12a long-range PCR strategy was adopted to determine whether a small genomic deletion encompassing exon 5 had occurred.
Primer pairs were designed at increasing intervals around exon 5. A corresponding 5. Endocrine assessment and bone densitometry Follicle stimulating hormone FSH and luteinizing hormone LH concentrations were measured using standard radioimmunoassay kits.
Bone breast cancer hormonal or anti-estrogen therapy density was assessed at the lumbar spine L1—L4 using dual-electron x-ray absorptiometry Hologic QDR and expressed as a z-score. Structural modeling The positions of the point mutations within the tertiary structure of aromatase were predicted using a three-dimensional homology model of human aromatase based on CYP2C9 PDB code 1TQA The entire cDNA sequences of all mutant constructs were verified prior to further studies.
Actualizări în tratamentul hormonal al cancerului de sân
A β-galactosidase expression plasmid pSV-β-galactosidase control vector, Promega was co-transfected in a molar ratio of Aromatase activity was determined 24 hr later by the production of 3H2O from the substrate [1β-3H]androstenendione Perkin Elmerusing methods described previously In one set of studies, a saturated point assay was performed by incubating cells in 80 nM final concentration of [1β-3H]androstenendione in serum free medium for 6 hr.
In another set of vaccino papilloma virus testimonianze, a breast cancer hormonal or anti-estrogen therapy curve assay was performed by incubating transfected cells with 0, 5, 10, 20, 50,nM final concentration of [1β-3H]androstenendione in serum free medium for 3 hr.
Aromatase activity was calculated by measuring radioactivity with a scintillation counter and adjusting for transfection efficiency using β-galactosidase activity, and total protein expression as determined by standard Bradford assay Bio-Rad.
Aromatase expression and protein size was confirmed by immunoblot Western analyses with a mouse anti-human aromatase antibody directed to codons Serotec.
All experiments were performed in triplicate, on at least three separate occasions.
Empty vector, WT and mutant aromatase constructs 0. Cells were visualized using a Zeiss Axioskop microscope and camera. A history of maternal voice changes was noted during pregnancy. At Karyotype was 46,XX, basal gonadotropin FSH, LH and androgen androstenedione, testosterone concentrations were elevated, and estradiol was low but detectable Table 1.
Adrenal steroidogenic defects were excluded. Pelvic ultrasound revealed a 6.
Bone age was delayed by 2. Her breast development did not progress further than Tanner stage 2 and she complained of facial hair at Thus, ethinylestradiol was used to fully induce breast development and cyproterone acetate was given to prevent further hair growth.