The HLA-G gene is primarily expressed in placental cells that invade the maternal decidua during pregnancy. This gene encodes multiple isoforms that fulfill a variety of functions at the maternal-fetal interface throughout gestation. Recently, a null allele for the most abundant HLA-G isoform was associated with recurrent miscarriage in two independent studies, suggesting that reduced levels of the HLA-G1 protein may compromise successful pregnancy. We initiated the present study to determine whether other polymorphisms that could affect expression levels of HLA-G were associated with fetal loss in women participating in a 15-year prospective study of pregnancy outcome. We genotyped these subjects for 18 single-nucleotide polymorphisms in the 1,300 bp upstream of exon 1, 13 of which were identified as part of this study, as well as for an insertion/deletion (in/del) polymorphism in the 3' untranslated region. The 18 SNPs defined eight unique haplotypes. One polymorphism, -725C/G, was associated with fetal loss, with an increased risk for miscarriage in couples in which both partners carried the -725G allele, compared with couples not carrying this allele (odds ratio 2.76, 95% confidence interval 1.08-7.09; P=.035). Further, the G at nucleotide -725 creates a CpG dinucleotide, and we demonstrate that this CpG site is methylated on -725G alleles. Overall, this study identified extraordinary levels of variation in the 5'-upstream regulatory region of HLA-G and provides evidence for an association between a promoter-region SNP and fetal loss rates, further attesting to the novel features and critical role of this gene in pregnancy.
Apoptosis has long been considered to be the prevailing mechanism of cell death in response to chemotherapy. Currently, a more heterogeneous model of tumor response to therapy is acknowledged wherein multiple modes of death combine to generate the overall tumor response. The resulting mechanisms of cell death are likely determined by the mechanism of action of the drug, the dosing regimen used, and the genetic background of the cells within the tumor. This study describes a nonapoptotic response to docetaxel therapy in human breast cancer cells of increasing cancer progression (MCF-10A, MCF-7, and MDA-mb-231). Docetaxel is a microtubule-stabilizing taxane that is being used in the clinic for the treatment of breast and prostate cancers and small cell carcinoma of the lung. The genetic backgrounds of these cells were characterized for the status of key pathways and gene products involved in drug response and cell death. Cellular responses to docetaxel were assessed by characterizing cell viability, cell cycle checkpoint arrest, and mechanisms of cell death. Mechanisms of cell death were determined by Annexin V binding and scoring of cytology-stained cells by morphology and transmission electron microscopy. The primary mechanism of death was determined to be mitotic catastrophe by scoring of micronucleated cells and cells undergoing aberrant mitosis. Other, nonapoptotic modes of death were also determined. No significant changes in levels of apoptosis were observed in response to docetaxel. [Mol Cancer Ther 2005;4(10):1495 -504]
Nuclear lamins comprise the nuclear lamina, a scaffoldlike structure that lines the inner nuclear membrane. B-type lamins are present in almost all cell types, but A-type lamins are expressed predominantly in differentiated cells, suggesting a role in maintenance of the differentiated state. Previous studies have shown that lamin A/C is not expressed during mouse development before day 9, nor in undifferentiated mouse embryonic carcinoma cells. To further investigate the role of lamins in cell phenotype maintenance and differentiation, we examined lamin expression in undifferentiated mouse and human embryonic stem (ES) cells. Wide-field and confocal immunofluorescence microscopy and semiquantitative reverse transcription-polymerase chain reaction analysis revealed that undifferentiated mouse and human ES cells express lamins B1 and B2 but not lamin A/C. Mouse ES cells display high levels of lamins B1 and B2 localized both at the nuclear periphery and throughout the nucleoplasm, but in human ES cells, B1 and B2 expression is dimmer and localized primarily at the nuclear periphery. Lamin A/C expression is activated during human ES cell differentiation before downregulation of the pluripotency marker Oct-3/4 but not before the downregulation of the pluripotency markers Tra-1-60, Tra-1-81, and SSEA-4. Our results identify the absence of A-type lamin expression as a novel marker for undifferentiated ES cells and further support a role for nuclear lamins in cell maintenance and differentiation.
Background: Poor postnatal weight gain in very low birth weight (VLBW) preterm infants has been shown to have a negative effect on neurodevelopment. However, the dose-dependent neurodevelopmental consequences of linear stunting in this population have not previously been assessed. Understanding this relationship is important because organ growth and differentiation are more tightly linked to lean body mass and thus linear growth. Objective: To assess the duration and clinical determinants of poor linear growth and its relationship to neurodevelopment in preterm infants. Methods: Weight, recumbent length and head circumference were recorded at birth, hospital discharge, and at 4, 12 and 24 months corrected age (CA) in 62 VLBW infants. Standardized Z-scores for weight (WZ), length (LZ) and head circumference (HCZ) were calculated and assessed as a function of inpatient clinical factors using linear regression models. Twenty-four-month neurodevelopmental function was analyzed as a function of growth status. Results: Mean LZ was lower than WZ (p = 0.004) at hospital discharge, was related in part to illness severity and remained lower than baseline LZ until 24 months CA. Controlling for WZ and HCZ at each age, lower LZ at 4 and 12 months CA was associated with lower cognitive function scores at 24 months CA (p ≤ 0.03). Conclusions: Nutritional and nonnutritional factors influenced the degree of pre- and postdischarge linear growth suppression in VLBW infants, which in turn was negatively associated with developmental outcomes at 24 months CA. Since linear growth correlates with brain growth and indexes a number of clinical factors, it is an important biomarker that can be used in VLBW infants to predict long-term developmental outcomes.
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