The FMR1 CGG repeat mouse displays ubiquitin-positive intranuclear neuronal inclusions; implications for the cerebellar tremor/ataxia syndrome

Recent studies have reported that alleles in the premutation range in the FMR1 gene in males result in increased FMR1 mRNA levels and at the same time mildly reduced FMR1 protein levels. Some elderly males with premutations exhibit an unique neurodegenerative syndrome characterized by progressive intention tremor and ataxia. We describe neurohistological, biochemical and molecular studies of the brains of mice with an expanded CGG repeat and report elevated Fmr1 mRNA levels and intranuclear inclusions with ubiquitin, Hsp40 and the 20S catalytic core complex of the proteasome as constituents. An increase was observed of both the number and the size of the inclusions during the course of life, which correlates with the progressive character of the cerebellar tremor/ataxia syndrome in humans. The observations in expanded-repeat mice support a direct role of the Fmr1 gene, by either CGG expansion per se or by mRNA level, in the formation of the inclusions and suggest a correlation between the presence of intranuclear inclusions in distinct regions of the brain and the clinical features in symptomatic premutation carriers. This mouse model will facilitate the possibilities to perform studies at the molecular level from onset of symptoms until the final stage of the disease

Human ovarian tumors of epithelial origin express PDGF in vitro and in vivo

In human malignant mesothelioma cell lines an elevation of the expression of the genes for the PDGF A-chain, PDGF B-chain, and PDGF β-receptor was found compared to normal mesothelial cells. As ovarian epithelial tumors originate from the ovarian surface epithelium, which is of mesothelial origin, we investigated PDGF chain and PDGF receptor mRNA expression in six human ovarian cell lines of epithelial origin and a granulosa tumor cell line. All six investigated ovarian epithelial tumor cell lines expressed the PDGF A- and B-chain genes, while the granulosa tumor cell line expressed the PDGF A-chain gene only. Expression of PDGF receptors was not f

High Δnp73/TAp73 ratio is associated with poor prognosis in acute promyelocytic leukemia

The TP73 gene transcript is alternatively spliced and translated into the transcriptionally active (TAp73) or inactive (DNp73) isoforms, with opposite effects on the expression of p53 target genes and on apoptosis induction. The imbalance between DNp73 and TAp73 may contribute to tumorigenesis and resistance to chemotherapy in human cancers, including hematologic malignancies. In acute promyelocytic leukemia (APL), both isoforms are expressed, but their relevance in determining response to therapy and contribution to leukemogenesis remains unknown. Here, we provide the first evidence that a higher ΔNp73/TAp73 RNA expression ratio is associated with lower survival, lower disease-free survival, and higher risk of relapse in patients with APL homogeneously treated with all-trans retinoic acid and anthracycline-based chemotherapy, according to the International Consortium on Acute Promyelocytic Leukemia (IC-APL) study. Cox proportional hazards modeling showed that a high ΔNp73/TAp73 ratio was independently associated with shorter overall survival (hazard ratio, 4.47; 95% confidence interval, 1.64-12.2; P 5 .0035). Our data support the hypothesis that the ΔNp73/TAp73 ratio is an important determinant of clinical responsein APL and may offer a therapeutic target for enhancing chemosensitivity in blast cells