MicroRNAs (miRNA) represent a novel class of genes that function as negative regulators of gene expression. Recently, miRNAs have been implicated in several cancers. However, aberrant miRNA expression and its clinicopathologic significance in human ovarian cancer have not been well documented. Here, we show that several miRNAs are altered in human ovarian cancer, with the most significantly deregulated miRNAs being miR-214, miR-199a*, miR-200a, miR-100, miR125b, and let-7 cluster. Further, we show the frequent deregulation of miR-
We have established a method for the detection of DNA damage and its repair in human telomeres, the natural ends of chromosomes which are necessary for replication and critical for chromosomal stability. We find that ultraviolet light-induced pyrimidine dimers in telomeric DNA are repaired less efficiently than endogenous genes but more efficiently than inactive, noncoding regions. We have also measured telomeric length, telomeric DNA damage, and its repair in relation to the progression of aging. Telomeres are shorter in fibroblasts from an old donor compared to fibroblasts from a young donor, shortest in cells from a patient with the progeroid disorder Werner syndrome, and relatively long in fibroblasts from a patient with Alzheimer disease. Telomeric DNA repair efficiency is lower in cells from an old donor than in cells from a young donor, normal in Alzheimer cells, and slightly lower in Werner cells. It is possible that this decline in telomeric repair with aging is of functional significance to an age-related decline in genomic stability.
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