Analysis of 14q+ derivative chromosomes in non-Hodgkin's lymphomas by fluorescence in-situ hybridization

Deciphering the genotype and phenotype of hairy cell leukemia: clues for diagnosis and treatment

Introduction: Hairy cell leukemia (HCL) is a rare, indolent B-cell neoplasm. The classical variant of the disease is characterized by the BRAF V600E mutation, which is present in virtually all cases. How this mutation leads to the signs and symptoms of the disease is currently not known. Areas covered: This review explores the genetic background of HCL, especially the BRAF V600E driver mutation, but passenger mutations and their effects are also included. The clinical significance of BRAF mutations in other cancer types is discussed, as well as BRAF- induced senescence. An overview of the major forms of treatment of HCL (cytostatic drugs, specific BRAF inhibitors, B cell-specific antibodies) is given. Finally, possible mechanisms of the monocytopenia and hairy morphology so typical of this disease are discussed. Expert opinion: Although being a rare disease, HCL and its pathogenesis can yield important information about BRAF-related cancer metabolism. Many aspects of the disease are still unclear, but with the right resources, this could change. This can lead to a more efficient and specific treatment, thus leading to decreased morbidity.

Small ISGs coming forward

Interferons (IFNs) were first characterized as antiviral proteins. Since then, IFNs have proved to be involved in malignant, angiogenic, inflammatory, immune, and fibrous diseases and, thus, possess a broad spectrum of pathophysiologic properties. IFNs activate a cascade of intracellular signaling pathways leading to upregulation of more than 1000 IFN-stimulated genes (ISGs) within the cell. The function of some of the IFN-induced proteins is well described, whereas that of many others remain poorly characterized. This review focuses on three families of small intracellular and intrinsically nonsecreted proteins (10-20 kDa) separated into groups according to their amino acid sequence similarity: the ISG12 group (6-16, ISG12, and ISG12-S), the 1-8 group (9-27/Leu13, 1-8U, and 1-8D), and the ISG15 group (ISG15/UCRP). These IFN-induced genes are abundantly and widely expressed and mainly induced by type I IFN. ISG15 is very well described and is a member of the ubiquitin-like group of proteins. 9-27/Leu-13 associates with CD81/TAPA-1 and plays a role in B cell development. The functions of 1-8U, 1-8D, 6-16, ISG12, and ISG12-S proteins are unknown at present.

Is a duplication of 14q32 a new recurrent chromosomal alteration in B-cell non-Hodgkin lymphoma?

Identification of clonal chromosomal abnormalities involving 14q32 and its association with specific histological subtypes of non-Hodgkin lymphoma (NHL) has provided substantial insight to the genetic events leading to the disease. However, in some cases with inferior morphology of tumor cell chromosomes, the additional segment on chromosome 14 remains unidentified by cytogenetic banding techniques alone. To elucidate the origin of the additional chromosomal segment and to correlate the newly determined alterations with histology, metaphases from 15 NHL patients with add(14)(q32) were examined using fluorescence in situ hybridization (FISH) techniques after cytogenetic analysis had been performed. We found the duplication of 14q involving the q32 region in 6 cases with a dup(14) (q32) in 4 cases and a dup(14)(q24q32) in 2 cases. In 8 cases, FISH unveiled known NHL associated translocations; a t(14;18)(q32;q21) in 4 cases, a t(11;14)(q13;q32) in 2 cases, a t(8;14)(q24;q32) and a t(9;14)(p13;q32) in 1 case each. We also noted a t(14;17)(q32;q21) in 1 case. The use of FISH was a valuable asset in determining the origin of the additional material on chromosome 14q32, and helped resolve a group of B-cell NHLs with involvement of a duplicated 14q32 region.

Cloning, chromosomal localization and promoter analysis of the human transcription factor YY1

Yin Yang 1 (YY1) is a protein that activates and represses transcription of a large number of cellular and viral genes. In addition, studies suggest that YY1 may play an important role in development and differentiation. Here, we report the isolation and analysis of a YY1 genomic clone from a lambda human liver library. Fluorescence in situ hybridization with the YY1 clone has localized the YY1 gene to chromosome 14 band q32. A major YY1 gene transcription initiation site has been mapped to 478 bp upstream of the ATG translation start site. The proximal promoter contains multiple Sp1 transcription factor binding sites but lacks a consensus TATA or CCAAT box. Transient transfections and detailed deletion analyses localized the promoter to no more than 277 bp upstream from the major transcription start site. Finally, we have found that overexpression of the adenovirus E1A protein represses expression of a reporter gene directed by the YY1 promoter.