The expression of neurotrophins and their receptors, the low-affinity nerve growth factor receptor (p75 LNGFR ) and the Trk receptors (TrkA , TrkB, and TrkC) , was investigated in human bone marrow from 16 weeks fetal age to adulthood. Using reverse transcription-polymerase chain reaction , all transcripts encoding for catalytic and truncated human TrkB or TrkC receptors were detected together with trkAI transcripts , whereas trkAII transcripts were found only in control nerve tissues. Transcripts for the homologue of the rat truncated TrkC(ic113) receptor were identified for the first time in human tissue. Stromal adventitial reticular cells were found immunoreactive for all neutrophin receptors. In contrast, hematopoietic cell types were not immunoreactive for p75 LNGFR Nerve growth factor (NGF) 1 is the prototype of a family of related neurotrophic factors known as neurotrophins (NT), which also includes brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4, also called neurotrophin-5 or NT-5 in humans) (reviewed in Lindsay et al 2 ). NT are trophic factors for the growth, differentiation, and survival of specific subsets of neurons in the developing and mature nervous system. 2 NT can interact with two classes of receptors with distinct ligand affinity and specificity. The low-affinity nerve growth factor receptor, p75 LNGFR , binds all known NT. 3,4 Tyrosine kinase receptors of the Trk family are essential components of NT high-affinity binding sites that trigger neuronal survival, growth, and differentiation. 5 TrkA is the preferred receptor for NGF 6,7 but has a lower efficiency for NT-3 or NT-4/5. TrkB is bound by BDNF and NT-4 and, to a lesser extent, by 9 TrkC is characterized by a unique ligand, NT-3. 10 In some cell lines, TrkA is sufficient to form high-affinity binding sites through homodimerization, 7 whereas p75 LNGFR potentiates TrkA activation by NGF in the PC12 cell line. 11 Variants of tyrosine kinase receptors (TK ϩ ) with insertions in either the extracellular domain (ECD) or the tyrosine kinase domain have been identified for trkA 12,13 and trkC [13][14][15][16] in both human and rat.Truncated receptors lacking the kinase domain (TK Ϫ ) have been described for TrkB and TrkC but not for TrkA. [15][16][17][18] These receptors may function as dominant negative isoforms or immunoadhesins. 13,19,20 Both TK ϩ and TK Ϫ receptors have been detected in neurons while only truncated TrkB and TrkC isoforms have been detected primarily in nonneuronal cells. [15][16][17][18]21 The expression of functional NGF receptors has been detected in several bone marrow-derived cells such as monocytes, 22 mastocytes, 23,24 and B or T cell clones. [25][26][27][28] Among its pleiotropic effects, NGF induces platelet shape changes, 29 triggers monocyte cytotoxic activity, 22 and induces basophilic cell differentiation 30 -32 and mast cell development and degranulation. 24,33 However, NGF receptors have not been consistently detected on bone marrow cells. Although trkA and p75 L...

Key Points• Besides maintaining short telomeres, telomerase is required for cell proliferation and tumor growth in CTCL.Telomere erosion may be counteracted by telomerase. Here we explored telomere length (TL) and telomerase activity (TA) in primary cutaneous T-cell lymphoma (CTCL) by using quantitative polymerase chain reaction and interphase quantitative fluorescence in situ hybridization assays. Samples from patients with Sézary syndrome (SS), transformed mycosis fungoides (T-MF), and cutaneous anaplastic large cell lymphoma were studied in parallel with corresponding cell lines to evaluate the relevance of TL and TA as target candidates for diagnostic and therapeutic purposes. Compared with controls, short telomeres were observed in aggressive CTCL subtypes such as SS and T-MF and were restricted to neoplastic cells in SS. While no genomic alteration of the hTERT (human telomerase catalytic subunit) locus was observed in patients' tumor cells, TA was detected. To understand the role of telomerase in CTCL, we manipulated its expression in CTCL cell lines. Telomerase inhibition rapidly impeded in vitro cell proliferation and led to cell death, while telomerase overexpression stimulated in vitro proliferation and clonogenicity properties and favored tumor development in immunodeficient mice. Our data indicate that, besides maintenance of TL, telomerase exerts additional functions in CTCL. Therefore, targeting these functions might represent an attractive therapeutic

The World Health Organization-European Organization for Research and Treatment of Cancer has individualized three main categories among the primary cutaneous B cell lymphoma (PCBCL): leg-type primary cutaneous large B cell lymphoma (PCLBCL leg type), primary cutaneous follicle center lymphoma (PCFCL), and primary cutaneous marginal zone lymphoma (PCMZL). The genetic features of 21 PCBCL cases (six PCLBCL leg type four PCFCL large cells, seven PCFCL small cells, and four PCMZL) were investigated by comparative genomic hybridization (CGH array). Fluorescent in situ hybridization (FISH) analysis was performed to confirm CGH array data and to detect lymphoma-associated gene rearrangements. p14(ARF)/p16(INK4a) CDKN2A gene quantification, methylation analysis, and immunohistochemical detection were also performed. CGH array showed a higher number of recurrent genetic imbalances in PCLBCL leg type (mean 62) than in PCFCL large cells (mean 34). PCFCL small cells and PCMZL exhibited fewer chromosomal alterations (mean 24 and 9). FISH analysis provided concordant results with CGH array data in 97% (98 of 101) assays and demonstrated a t(8;14)(q24;q32) in two of six PCLBCL leg type. Recurrent deletions in 9p21 (p14(ARF)/p16(INK4a)CDKN2A) were a constant finding in PCLBCL leg type (six of six). Conversely, PCFCL large cells exhibited recurrent 1p36 deletions (four of four) without deletion in 9p21 (zero of four). The diagnostic and prognostic impact of the p16(INK4a)CDKN2A gene status in PCBCL should therefore be confirmed on a larger series.

ObjectivesRecent studies have shown that telomere length was significantly reduced in placentas collected at delivery from pregnancies complicated by intrauterine growth restriction secondary to placental insufficiency. Placental telomere length measurement during ongoing pregnancies complicated by intrauterine growth restriction has never been reported. This was the main objective of our study.MethodsIn our center, late chorionic villus samplings were performed between 18 and 37 weeks of amenorrhea in 24 subjects with severe intrauterine growth restriction (cases) and in 28 subjects with other indications for prenatal diagnosis (controls). Placental insufficiency was assessed by histo-pathological examination. Relative measurement of telomere length was carried out prospectively by quantitative Fluorescent In Situ Hybridization using fluorescent Peptide Nucleic Acid probes on interphase nuclei obtained from long-term cultured villi and with an automated epifluorescent microscope. A quantitative Polymerase Chain Reaction technique was performed to confirm the quantitative Fluorescent In Situ Hybridization results. The number of copies of gene loci encoding the RNA template (hTERC) and the catalytic subunit (hTERT) of the enzyme complex telomerase were also estimated in these placentas by Fluorescent In Situ Hybridization.ResultsMean fluorescence intensity of telomere probes estimated by quantitative Fluorescent In Situ Hybridization was significantly less for cases compared to controls (p<0.001). This result indicated that mean telomere length was significantly reduced in placentas during pregnancies complicated by intrauterine growth restriction. Reduced telomere length was confirmed by the quantitative Polymerase Chain Reaction technique. No copy number variation of the hTERC and hTERT loci was noticed for cases, or for controls.ConclusionThis study clearly demonstrates a reduction of placental telomere length in ongoing pregnancies (from 18 to 37 weeks of amenorrhea) complicated by severe intrauterine growth restriction secondary to placental insufficiency.

By prospectively studying immunoglobulin heavy chain gene (IgH) and T cell receptor gamma (TCRgamma) gene rearrangements in 398 lymphoma cases, a dual genotype was observed in 13% of B cell and 11% of T cell lymphomas. According to histological subtype, the highest incidence was observed for mantle cell lymphomas (32%) and lymphoplasmacytic lymphoma (21%) among B cell lymphomas, and for angioimmunoblastic lymphoma (AILT) (46%) and Sézary syndrome (SS) (50%) among T cell lymphomas. To determine whether the dual genotype corresponds to the presence of two distinct monoclonal populations or to the presence of both rearrangements within the same lymphoma cells, single-cell microdissection was used after immunohistochemistry and a single-cell combined IgH and TCRgamma gene analysis was designed after a whole-genome amplification step. This protocol was applied to the study of two nodal B cell lymphomas (one diffuse large B cell lymphoma and one mantle cell lymphoma) and two cutaneous T cell lymphomas (one AILT and one SS). Two cases (SS and mantle cell lymphoma) were true bigenotypic lymphomas, as both IgH and TCRgamma monoclonal rearrangements were detected in the same cells. Conversely, in the diffuse large B cell lymphoma and AILT cases, large CD22+ single cells exhibited only the monoclonal IgH rearrangement but not the TCRgamma gene that was detected in CD3+ single cells. Such an approach allows the identification of true bigenotypic lymphoma among dual genotypic lymphoma. Specific genetic alterations may be further amplified from microdissected cryopreserved material, such as the t(11;14) breakpoint detected in bigenotypic B cells of the mantle cell lymphoma case.