Increased genomic alteration complexity and telomere shortening in B-CLL cells resistant to radiation-induced apoptosis.

B-cell chronic lymphocytic leukemia (B-CLL) results in an accumulation of mature CD5(+)/CD23(+) B cells due to an uncharacterized defect in apoptotic cell death. B-CLL is not characterized by a unique recurrent genomic alteration but rather by genomic instability giving rise frequently to several chromosomal aberrations. Besides we reported that approximately 15% of B-CLL patients present malignant B-cells resistant to irradiation-induced apoptosis, contrary to approximately 85% of patients and normal human lymphocytes.

Structure and properties of transcriptional networks driving selenite stress response in yeasts.

Background: Stress responses provide valuable models for deciphering the transcriptional networks controlling the adaptation of the cell to its environment. We analyzed the transcriptome response of yeast to toxic concentrations of selenite. We used gene network mapping tools to identify functional pathways and transcription factors involved in this response.

The central role of PDR1 in the foundation of yeast drug resistance.

The widespread pleiotropic drug resistance (PDR) phenomenon is well described as the long term selection of genetic variants expressing constitutively high levels of membrane transporters involved in drug efflux. However, the transcriptional cascades leading to the PDR phenotype in wild-type cells are largely unknown, and the first steps of this phenomenon are poorly understood. We investigated the transcriptional mechanisms underlying the establishment of an efficient PDR response in budding yeast.

B-cell chronic lymphocytic leukaemia: a polymorphic family unified by genomic features.

Human cancer is characterised by complex molecular aberrations which result in a wide variety of clinical manifestations. B-cell chronic lymphocytic leukaemia (B-CLL) is particularly diverse, both in terms of molecular changes and clinical course, and consequently our understanding of the pathology of this disease is generally poor. Furthermore, the heterogeneity of this tumour type coupled with the absence of an obvious genetic "hallmark", such as gain of oncogene function or loss of suppressor-gene function, has led many investigators to question whether B-CLL is a single disease entity.

Spatio-temporal heterogeneity and cell-specificity of long-term potentiation-induced mRNA expression in the dentate gyrus in vivo.

Gene expression in neurones can vary in response to neuronal activation. In this study, to analyse the spatio-temporal dynamics of the transcriptional response of three genes following the induction of long-term potentiation within the entire dentate gyrus in vivo, two new complementary approaches based on in situ hybridisation were developed: three-dimensional reconstruction of the pattern of mRNA expression within the entire dentate gyrus; and radioactive co-detection of two mRNA species allowing quantification of two different mRNAs in the same brain section. Zif268, Homer and syntaxin 1B genes were studied, and their regulated expression was examined three times after the induction of long-term potentiation.