Epigenetic alterations and an increased frequency of micronuclei in women with fibromyalgia.

Fibromyalgia (FM), characterized by chronic widespread pain, fatigue, and cognitive/mood disturbances, leads to reduced workplace productivity and increased healthcare expenses. To determine if acquired epigenetic/genetic changes are associated with FM, we compared the frequency of spontaneously occurring micronuclei (MN) and genome-wide methylation patterns in women with FM (n = 10) to those seen in comparably aged healthy controls (n = 42 (MN); n = 8 (methylation)). The mean (sd) MN frequency of women with FM (51.4 (21.9)) was significantly higher than that of controls (15.8 (8.5)) (χ (2) = 45.552; df = 1; P = 1.49 × 10(-11)). Significant differences (n = 69 sites) in methylation patterns were observed between cases and controls considering a 5% false discovery rate. The majority of differentially methylated (DM) sites (91%) were attributable to increased values in the women with FM. The DM sites included significant biological clusters involved in neuron differentiation/nervous system development, skeletal/organ system development, and chromatin compaction. Genes associated with DM sites whose function has particular relevance to FM included BDNF, NAT15, HDAC4, PRKCA, RTN1, and PRKG1. Results support the need for future research to further examine the potential role of epigenetic and acquired chromosomal alterations as a possible biological mechanism underlying FM.

Increased frequency of micronuclei in adults with a history of childhood sexual abuse: a discordant monozygotic twin study.

BACKGROUND: Childhood sexual abuse (CSA) is a traumatic life event associated with an increased lifetime risk for psychopathology/morbidity. The long-term biological consequences of CSA-elicited stress on chromosomal stability in adults are unknown. The primary aim of this study was to determine if the rate of acquired chromosomal changes, measured using the cytokinesis-block micronucleus assay on stimulated peripheral blood lymphocytes, differs in adult female monozygotic twins discordant for CSA. METHODS: Monozygotic twin pairs discordant for CSA were identified from a larger population-based sample of female adult twins for whom the experience of CSA was assessed by self-report (51 individuals including a reference sample). Micronuclei (MN) contain chromatin from structurally normal or abnormal chromosomes that are excluded from the daughter nuclei during cell division and serve as a biomarker to assess acquired chromosomal instability. RESULTS: Female twins exposed to CSA exhibited a 1.63-fold average increase in their frequency of MN compared to their nonexposed genetically identical cotwins (Paired t-test, t16 = 2.65, P = 0.017). No additional effects of familial factors were detected after controlling for the effect of CSA exposure. A significant interaction between CSA history and age was observed, suggesting that the biological effects of CSA on MN formation may be cumulative. CONCLUSIONS: These data support a direct link between CSA exposure and MN formation measured in adults that is not attributable to genetic or environmental factors shared by siblings. Further research is warranted to understand the biological basis for the observed increase in acquired chromosomal findings in people exposed to CSA and to determine if acquired somatic chromosomal abnormalities/somatic clonal mosaicism might mediate the adult pathology associated with CSA.

Mechanisms leading to the formation of micronuclei containing sex chromosomes differ with age.

The frequency of spontaneously occurring micronuclei (MN) increases with age, with many of these MN containing sex chromatin. However, it is not known if this MN frequency increase is attributable to a higher number of the same cellular events that occur in younger people, or if a different sex chromosomal instability mechanism(s) arises with age. To gain insight regarding this question, the total number of signals present in MN and their corresponding binucleates, was scored in older (ages 40-80+ y.o.; n=40) compared to younger (7-39 y.o.; n=19) individuals using probes specific for the X and Y chromosomes. In 19.9% of the cells scored at least one sex chromatin positive micronucleus was present. A significant decrease in cells having a "corrective" loss pattern (i.e. trisomy rescue, leading to euploid binucleates following sex chromatin exclusion into the MN) was observed with increasing age for the Y chromosome in males (p=0.022) and the X chromosome in females (p=0.004). In addition, a significant increase (p<0.001) in cells having multiple signals beyond those expected from a single cellular error was observed in the older compared to younger study participants, with these imbalances resulting from cells having either a single micronucleus with multiple signals, or cells having multiple MN. Collectively, these findings suggest that age-related increases in MN frequencies reflect both gains in the occurrence of similar cellular errors, as well as changes in the types of chromosomal findings that occur. Importantly, these results also illustrate that while MN frequencies reflect acquired abnormalities, they may also reflect cellular responses to "correct" an error, particularly when evaluated in young individuals. Therefore, when analyzing MN frequencies, one may also wish to evaluate the imbalances present in both the binucleates and MN to facilitate the recognition of varying cellular responses to environmental or genotoxic exposures.

Genetic and environmental influences on spontaneous micronuclei frequencies in children and adults: a twin study.

The primary aim of this study was to quantify genetic and environmental influences on the frequency of spontaneously occurring micronuclei in children and adults. To meet this aim, a total of 63 male and female twin pairs and 19 singletons (145 individuals) were evaluated, ranging in age from 7 to 85 years. Micronuclei frequencies significantly increased with age for both genders (r = 0.49, P < 0.001), with the lowest and highest rates being seen in the 7- to 9 (mean = 0.56%, SD = .28) and 60- to 69-year-olds (mean = 2.12%, SD = 1.0), respectively. This age effect was significantly more pronounced in females than males (P = 0.017). In addition to the main effect of age, the completion of puberty in either gender (P = 0.036) and menopause in females (P = 0.024) was associated with a significant increase in micronuclei frequencies. Genetic model fitting indicated that influences from both additive genetic (65.2% of variance) and unique environmental (34.8% of variance) sources best explained the observed micronuclei frequencies in monozygotic and dizygotic twin pairs. Self-reported health conditions associated with an increased frequency of micronuclei included a history of allergies (P < 0.007) and migraines (P = 0.026). Multivitamin use was also associated with increased micronuclei frequencies (P = 0.004). In contrast, significantly lower micronuclei frequencies were associated with arthritis (P = 0.002), as well as consuming fruit (P = 0.014), green, leafy vegetables (P < 0.001) and/or folate-enriched bread (P = 0.035). A sex-specific effect, resulting in a significantly increased frequency of micronuclei with tobacco usage, was observed for females (but not males). Gender differences also moderated the impact of vitamin D and calcium consumption. In conclusion, the frequency of spontaneously arising micronuclei in humans is a complex trait, being influenced by both heritable genetic and environmental components. Recognition of factors contributing to baseline levels of micronuclei should provide guidance to researchers in designing studies to evaluate agents hypothesised to influence chromosomal instability.

Transcription factor Late SV40 Factor (LSF) functions as an oncogene in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a highly aggressive cancer with no currently available effective treatment. Understanding of the molecular mechanism of HCC development and progression is imperative for developing novel, effective, and targeted therapies for this lethal disease. In this article, we document that the cellular transcription factor Late SV40 Factor (LSF) plays an important role in HCC pathogenesis. LSF protein was significantly overexpressed in human HCC cells compared to normal hepatocytes. In 109 HCC patients, LSF protein was overexpressed in >90% cases, compared to normal liver, and LSF expression level showed significant correlation with the stages and grades of the disease. Forced overexpression of LSF in less aggressive HCC cells resulted in highly aggressive, angiogenic, and multiorgan metastatic tumors in nude mice. Conversely, inhibition of LSF significantly abrogated growth and metastasis of highly aggressive HCC cells in nude mice. Microarray studies revealed that as a transcription factor, LSF modulated specific genes regulating invasion, angiogenesis, chemoresistance, and senescence. The expression of osteopontin (OPN), a gene regulating every step in tumor progression and metastasis, was robustly up-regulated by LSF. It was documented that LSF transcriptionally up-regulates OPN, and loss-of-function studies demonstrated that OPN plays an important role in mediating the oncogenic functions of LSF. Together, these data establish a regulatory role of LSF in cancer, particularly HCC pathogenesis, and validate LSF as a viable target for therapeutic intervention.