Primary ovarian insufficiency with t(5;13): a case report and literature review on disrupted genes.

OBJECTIVES: To report a woman with primary ovarian insufficiency (POI) with reciprocal translocation between chromosomes 5 and 13. METHODS: Chromosomal analysis (G-banding) of a 39-year-old woman with elevated gonadotropin levels and secondary amenorrhea and review of the literature with a special focus on disrupted genes at the reported breakpoints. RESULTS: A reciprocal translocation between the long arms of chromosomes 5 and 13 was identified in the patient (46,XX,t(5;13)(q13;q14)). Investigation of the breakpoints revealed that the 13q14.1 region encompasses FOXO1 (forkhead box 1) gene, which has an important role in granulosa cell function and follicle maturation. CONCLUSIONS: Autosomal translocations are rare in women with POI. We have reported the first case of a de novo reciprocal translocation involving chromosomes 5 and 13 in a POI patient. As one of the breakpoints encompasses the FOXO1 gene, it seems that disruption of this gene can be the cause of POI in this patient. This provides further evidence on the role of autosomal translocations in disrupting POI-associated genes. Therefore, concentrating on the genes at the breakpoints will be helpful to delineate the new biological pathways or genes involved in POI pathogenesis.

The effects of Nobiletin, Hesperetin, and Letrozole in a combination on the activity and expression of aromatase in breast cancer cells.

Nobiletin (NOB) and hesperetin (HES) are the citrus polymethoxyflavone and flavonone. Aromatase or cytochrome P450 (CYP19) enzyme is a key enzyme in estrogen biosynthesis. The objective of this study was to investigate the combinational effects of HES, NOB and letrozole (LET) as aromatase inhibitors on the activity and expression of aromatase in MCF-7 cells. In this study, aromatase enzyme activity based on the conversion of androgen substrate testosterone to 17ß-Estradiol was determined. Estradiol concentrations were measured using an electrochemiluminescence immunoassay. CYP19 gene expression was determined by quantitative real-time PCR. Our findings demonstrated that none of combinations including LET+NOB, LET+HES, LET+NOB+HES, and NOB+HES had no significant effects on aromatase activity and expression. The present study showed for the first time that the combination of HES, NOB, and LET had no effects on activity and expression of aromatase in MCF-7 breast cancer cells.

The individual or combinational effects of Hesperetin and Letrozole on the activity and expression of aromatase in MCF-7 cells.

Aromatase catalyzes the last and rate-limiting step in estrogen biosynthesis. Inhibition of estrogen production is a common strategy for breast cancer treatment. Citrus flavonoids have been confirmed to exhibit efficacious biological activities, particularly in cancer therapy. This study was carried out to investigate the effect of hesperetin on the activity and expression of aromatase and compare this property with letrozole as an aromatase inhibitor in MCF-7 breast cancer cell line. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assays in this study demonstrated that hesperetin at a concentration of 200 µM decreased cell viability in a time dependent manner (P<0.05). Aromatase activity assay, based on 17ß-Estradiol (E2) production from testosterone, revealed that hesperetin had no effect. Real-time PCR results indicated that treatment with 1µM concentration of hesperetin for 48 h significantly decreased relative aromatase expression (P =0.004). Combination of letrozole and hesperetin also had no effect on aromatase. The changes in activity paralleled the expression of aromatase. Likely, the reduction in aromatase activity was delayed in time along with the reduction in expression ratio; however additional studies are needed to confirm this. In conclusion, the present study showed that hesperetin could decrease expression of aromatase at low concentrations in MCF-7 breast cancer cells.

Genetic analysis of Iranian autosomal dominant polycystic kidney disease: new insight to haplotype analysis.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) caused by mutations in two PKD1 and PKD2 genes. Due to the complexity of the PKD1 gene, its direct mutation screening is an expensive and time-consuming procedure. Pedigree-based haplotype analysis is a useful indirect approach to identify the responsible gene in families with multiple affected individuals, before direct mutation analysis. Here, we applied this approach to investigate 15 appropriate unrelated ADPKD families, selected from 25 families, who referred for genetic counseling. Four polymorphic microsatellite markers were selected around each PKD1 and PKD2 loci. In addition, by investigating the genomic regions, two novel flanking tetranucleotide STR markers were identified. Haplotype analysis and calculating Lod score confirmed linkage to PKD1 in 9 families (60%) and to PKD2 in 2 families (13%). Linkage to both loci was excluded in one family (6.6%). In 2 families (13%) the Lod scores were inconclusive. Causative mutation was identified successfully by direct analysis in two families with confirmed linkage, one to PKD1 and another to PKD2 locus. The study showed that determining the causative locus prior to direct mutation analysis is an efficient strategy to reduce the resources required for genetic analysis of ADPKD families. This is more prominent in PKD2-linked families. Selection of suitable markers, and appropriate PCR multiplexing strategy, using fluorescent labeled primers and 3 primer system, will also add value to this approach.

No association of an insertion/deletion polymorphism in the angiotensin I converting enzyme gene with bipolar or unipolar affective disorders.

A recent Japanese study on the angiotensin I converting enzyme gene (ACE) insertion/deletion polymorphism reported that both the D allele (P < 0.02) and the DD genotype (P < 0.002) were significantly more frequent in affective disorder cases than in controls [Arinami et al., 1996: Biol Psychiatry 40:1122-1127]. A replication study was performed by using 157 bipolar I affective disorder cases, 169 major depressive disorder cases, and 313 controls. No significant association with this polymorphism was found in either disorder or in a combined affective disorder group. These results do not support the ACE gene having a major role in the etiology of either bipolar or unipolar affective disorders. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:733-735, 2000.

The ACE I allele is associated with increased risk for ruptured intracranial aneurysms.

Genetic and environmental factors play roles in the aetiology of ruptured intracranial aneurysms. Hypertension has been reported as a risk factor for intracranial aneurysm haemorrhage. We have tested if genotypes at the angiotensin converting enzyme (ACE) gene locus are associated with ruptured intracranial aneurysms. The insertion/deletion polymorphism in the ACE gene was genotyped in 258 subjects presenting in East Anglia with ruptured intracranial aneurysms (confirmed at surgery or angiographically) and 299 controls from the same region. ACE allele frequencies were significantly different in the cases and the controls (alleles chi(2)(1)=4.67, p=0.03). The I allele was associated with aneurysm risk (odds ratio for I allele v D allele = 1.3 (95% CI=1.02-1-65); odds ratio for II v DD genotype = 1.67 (95% CI=1.04-2.66)). The I allele at the ACE locus is over-represented in subjects with ruptured intracranial aneurysms. These data are supported by non-significant trends in the same direction in two previous smaller studies. Thus, this allele may be associated with risk for ruptured intracranial aneurysms.