TGF-beta1 induces bone marrow reticulin fibrosis in hairy cell leukemia

Simultaneous blastic plasmacytoid dendritic cell neoplasm and myelofibrosis: A case report

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an extremely rare and aggressive tumor with an unknown pathogenesis. Myelofibrosis (MF) is a type of myeloproliferative neoplasm. MF can be secondary to several hematological malignancies, including chronic myeloid leukemia, myelodysplastic syndrome and hairy cell leukemia. In the present report, a rare case of BPDCN secondary to MF is described. A 70-year-old male patient developed a large purplish-red rash with recurrent symptoms. BPDCN was confirmed by immunohistochemistry of a biopsy specimen and flow cytometry of bone marrow cells. Bone marrow histopathology revealed MF. Next-generation sequencing of peripheral blood revealed mutations in the Tet methylcytosine dioxygenase 2 and NRAS proto-oncogene GTPase genes. The patient underwent one cycle of chemoimmunotherapy, but the condition progressed, an infection developed and the patient eventually died. The present case suggests that BPDCN can occur in conjunction with MF and that the prognosis of such patients is poor. Pathological examination and genetic testing aided in the diagnosis and treatment. This case emphasizes the need to raise awareness of BPDCN among clinicians and to be alert to the potential for fatal infection in patients with BPDCN combined with MF following myelosuppression triggered during chemotherapy.

Hairy cell leukemia 2024: Update on diagnosis, risk-stratification, and treatment-Annual updates in hematological malignancies

DISEASE OVERVIEW

Hairy cell leukemia (HCL) and HCL-like disorders, including HCL variant (HCL-V) and splenic diffuse red pulp lymphoma (SDRPL), are a very heterogenous group of mature lymphoid B-cell disorders characterized by the identification of hairy cells, a specific genetic profile, a different clinical course and the need for appropriate treatment.

DIAGNOSIS

Diagnosis of HCL is based on morphological evidence of hairy cells, an HCL immunologic score of 3 or 4 based on the CD11c, CD103, CD123, and CD25 expression, the trephine biopsy which makes it possible to specify the degree of tumoral bone marrow infiltration and the presence of BRAFV600E somatic mutation.

RISK STRATIFICATION

Progression of patients with HCL is based on a large splenomegaly, leukocytosis, a high number of hairy cells in the peripheral blood, and the immunoglobulin heavy chain variable region gene mutational status. VH4-34 positive HCL cases are associated with a poor prognosis, as well as HCL with TP53 mutations and HCL-V.

TREATMENT

Patients should be treated only if HCL is symptomatic. Chemotherapy with risk-adapted therapy purine analogs (PNAs) are indicated in first-line HCL patients. The use of chemo-immunotherapy combining cladribine (CDA) and rituximab (R) represents an increasingly used therapeutic approach. Management of relapsed/refractory disease is based on the use of BRAF inhibitors (BRAFi) plus R, MEK inhibitors (MEKi), recombinant immunoconjugates targeting CD22, Bruton tyrosine kinase inhibitors (BTKi), and Bcl-2 inhibitors (Bcl-2i). However, the optimal sequence of the different treatments remains to be determined.

The protective role of the microenvironment in hairy cell leukemia treatment: Facts and perspectives

Hairy cell leukemia (HCL) is an incurable, rare lymphoproliferative hematological malignancy of mature B cAlthough first line therapy with purine analogues leads to positive results, almost half of HCL patients relapse after 5-10 years, and standard treatment may not be an option due to intolerance or refractoriness. Proliferation and survival of HCL cells is regulated by surrounding accessory cells and soluble signals present in the tumor microenvironment, which actively contributes to disease progression. In vitro studies show that different therapeutic approaches tested in HCL impact the tumor microenvironment, and that this milieu offers a protection affecting treatment efficacy. Herein we explore the effects of the tumor microenvironment to different approved and experimental therapeutic options for HCL. Dissecting the complex interactions between leukemia cells and their milieu will be essential to develop new targeted therapies for HCL patients.

Can plasma fibrinogen level predict bone marrow fibrosis?

Objective: We aimed to assess the possible relationship between plasma fibrinogen level and bone marrow fibrosis (BMF) grades in patients who had undergone bone marrow (BM) biopsy for any reason. Patients and Method: This retrospective cohort study included 106 participants aged 18 years and over who had undergone simultaneous BM biopsy and circulatory fibrinogen level measurement during 2020 and 2021 at our center. BMF grade was measured by the modified Bauermeister grading system (MBGS). Participants were divided into two groups according to MBGS as those without BMF and those with BMF. Results: Fifty-eight male were included in our study, and the median age of the patients was 63 (range: 19-97) years. Fibrinogen (p=0.004) and lactate dehydrogenase (LDH) (p=0.030) levels were significantly higher in the fibrosis group. Multiple regression revealed that high fibrinogen (≥359) and high LDH (≥238) were independently associated with a higher likelihood of fibrosis presence (adjusted for age and sex); however, diagnostic analyses revealed low accuracy. Conclusion: High plasma fibrinogen and LDH levels were found to be independently associated with the presence of BMF. However, it was also evident that neither of these parameters could be used for diagnostic purposes.

Updates in hairy cell leukemia (HCL) and variant-type HCL (HCL-V): rationale for targeted treatments with a focus on ibrutinib

Hairy cell leukemia (HCL) and HCL-like disorders such as hairy cell leukemia variant (HCL-V) and splenic diffuse red pulp lymphoma (SDRPL) are rare indolent B-cell malignancies. Purine analogs (PNAs), alone or in association with rituximab (R), are the standard of care for HCL in the first-line setting. However, PNAs are toxic and patients may become resistant to these drugs. Therefore, new therapeutic strategies are needed. Several recent in vitro studies highlighted the importance of the interactions between HCL cells and their microenvironment, in particular with bone marrow stromal cells, endothelial cells, and the extracellular matrix. In these interactions, chemokine receptors and adhesion molecules play a major role. Moreover, the importance of signaling pathways, like BRAF, BCR, and CXCR4 has been underlined. Bruton’s tyrosine kinase (BTK) is a fundamental signal transmitter of BCR and CXCR4 in HCL. Preclinical and recent clinical data showed an efficacy of ibrutinib, a BTK inhibitor (BTKi), in HCL and HCL-V. These promising results joined those of other emerging drugs like BRAF or MEK inhibitors and anti-CD22 immunotoxins.

Plain Language Summary

Bruton’s tyrosine kinase (BTK) inhibitors (BTKi) in hairy cell leukemia (HCL) and variant-type HCL The treatment of hairy cell leukemia (HCL) has changed significantly in recent years. In the first-line settings, treatment with purine analogs (PNAs) with or without anti-CD20 monoclonal antibodies remains the gold standard in 2022. In relapsed/refractory HCL, other drugs are needed: BRAF inhibitors: vemurafenib monotherapy with or without rituximab or dabrafenib in combination with trametinib, an MEK inhibitor (MEKi), as well as the anti-CD22 antibody drug conjugate moxetumomab pasudotox. There are arguments for the use of Bruton’s tyrosine kinase inhibitors (BTKi). Ibrutinib was recently tested in a multisite phase 2 study in 37 patients with either HCL (28 patients: 76%) or HCL-V (nine patients: 24%) including two who were previously untreated. Patients received single-agent ibrutinib at 420 mg daily (24 patients) or 840 mg daily (13 patients) until disease progression or unacceptable toxicity. The overall response rate (ORR) at 32 weeks was 24%, increasing to 36% at 48 weeks and reaching 54% at any time since starting ibrutinib. Seven patients achieved a complete response (CR) as the best response at any time on study, while 13 patients had a partial response (PR) and 10 patients had stable disease (SD). Interestingly, the response rate was not statistically different between HCL and HCL-V patients, suggesting that ibrutinib could be an option in both entities. The estimated 36-month progression-free survival (PFS) was 73% and the estimated 36-month overall survival (OS) was 85%, with no differences between HCL and HCL-V. The frequency of cardiovascular grade 1–2 adverse events (AEs) was 16% for atrial fibrillation; 3% for atrial flutter; 32% for hypertension; and 0%, 3%, and 11%, respectively, for grade ⩾ 3 AEs. Unlike in chronic lymphocytic leukemia (CLL), where the mechanism of action of ibrutinib is well known, the mechanism of action of ibrutinib in HCL appears to be unclear. No mutations were identified in patients with progressive disease, suggesting that the mechanisms of resistance could be different between HCL and CLL. The BTKi that are not yet approved are challenged by the new other targeted treatments.

Transforming Growth Factor-Beta Orchestrates Tumour and Bystander Cells in B-Cell Non-Hodgkin Lymphoma

Transforming growth factor-beta (TGFB) is a critical regulator of normal haematopoiesis. Dysregulation of the TGFB pathway is associated with numerous haematological malignancies including myelofibrosis, acute myeloid leukaemia, and lymphoid disorders. TGFB has classically been seen as a negative regulator of proliferation in haematopoiesis whilst stimulating differentiation and apoptosis, as required to maintain homeostasis. Tumours frequently develop intrinsic resistant mechanisms to homeostatic TGFB signalling to antagonise its tumour-suppressive functions. Furthermore, elevated levels of TGFB enhance pathogenesis through modulation of the immune system and tumour microenvironment. Here, we review recent advances in the understanding of TGFB signalling in B-cell malignancies with a focus on the tumour microenvironment. Malignant B-cells harbour subtype-specific alterations in TGFB signalling elements including downregulation of surface receptors, modulation of SMAD signalling proteins, as well as genetic and epigenetic aberrations. Microenvironmental TGFB generates a protumoural niche reprogramming stromal, natural killer (NK), and T-cells. Increasingly, evidence points to complex bi-directional cross-talk between cells of the microenvironment and malignant B-cells. A greater understanding of intercellular communication and the context-specific nature of TGFB signalling may provide further insight into disease pathogenesis and future therapeutic strategies.

SWATH-MS identification of CXCL7, LBP, TGFβ1 and PDGFRβ as novel biomarkers in human systemic mastocytosis

Mastocytosis is a rare myeloproliferative disease, characterised by accumulation of neoplastic mast cells in one or several organs. It presents as cutaneous or systemic. Patients with advanced systemic mastocytosis have a median survival of 3.5 years. The aetiology of mastocytosis is poorly understood, patients present with a broad spectrum of varying clinical symptoms that lack specificity to point clearly to a definitive diagnosis. Discovery of novel blood borne biomarkers would provide a tractable method for rapid identification of mastocytosis and its sub-types. Moving towards this goal, we carried out a clinical biomarker study on blood from twenty individuals (systemic mastocytosis: n = 12, controls: n = 8), which were subjected to global proteome investigation using the novel technology SWATH-MS. This identified several putative biomarkers for systemic mastocytosis. Orthogonal validation of these putative biomarkers was achieved using ELISAs. Utilising this workflow, we identified and validated CXCL7, LBP, TGFβ1 and PDGF receptor-β as novel biomarkers for systemic mastocytosis. We demonstrate that CXCL7 correlates with neutrophil count offering a new insight into the increased prevalence of anaphylaxis in mastocytosis patients. Additionally, demonstrating the utility of SWATH-MS for the discovery of novel biomarkers in the systemic mastocytosis diagnostic sphere.

The enduring legacy of Marie Curie: impacts of radium in 21st century radiological and medical sciences

PURPOSE

This review is focused on radium and radionuclides in its decay chain in honor of Marie Curie, who discovered this element.

MATERIALS AND METHODS

We conglomerated current knowledge regarding radium and its history predating our present understanding of this radionuclide.

RESULTS

An overview of the properties of radium and its dose assessment is shown followed by discussions about both the negative detrimental and positive therapeutic applications of radium with this history and its evolution reflecting current innovations in medical science.

CONCLUSIONS

We hope to remind all those who are interested in the progress of science about the vagaries of the process of scientific discovery. In addition, we raise the interesting question of whether Marie Curie's initial success was in part possible due to her tight alignment with her husband Pierre Curie who pushed the work along.

The Biology of Classic Hairy Cell Leukemia

Classic hairy cell leukemia (HCL) is a rare mature B-cell malignancy associated with pancytopenia and infectious complications due to progressive infiltration of the bone marrow and spleen. Despite tremendous therapeutic advances achieved with the implementation of purine analogues such as cladribine into clinical practice, the culprit biologic alterations driving this fascinating hematologic disease have long stayed concealed. Nearly 10 years ago, BRAF V600E was finally identified as a key activating mutation detectable in almost all HCL patients and throughout the entire course of the disease. However, additional oncogenic biologic features seem mandatory to enable HCL transformation, an open issue still under active investigation. This review summarizes the current understanding of key pathogenic mechanisms implicated in HCL and discusses major hurdles to overcome in the context of other BRAF-mutated malignancies.

The extracellular matrix: A key player in the pathogenesis of hematologic malignancies

Hematopoietic stem and progenitor cells located in the bone marrow lay the foundation for multiple lineages of mature hematologic cells. Bone marrow niches are architecturally complex with specific cellular, physiochemical, and biomechanical factors. Increasing evidence suggests that the bone marrow microenvironment contributes to the pathogenesis of hematological neoplasms. Numerous studies have deciphered the role of genetic mutations and chromosomal translocations in the development hematologic malignancies. Significant progress has also been made in understanding how the cellular components and cytokine interactions within the bone marrow microenvironment promote the evolution of hematologic cancers. Although the extracellular matrix is known to be a key player in the pathogenesis of various diseases, it's role in the progression of hematologic malignancies is less understood. In this review, we discuss the interactions between the extracellular matrix and malignant cells, and provide an overview of the role of extracellular matrix remodeling in sustaining hematologic malignancies.

TGF-β regulated leukemia cell susceptibility against NK targeting through the down-regulation of the CD48 expression

Transforming growth factor-β (TGF-β) is known to function as a dual role regulatory cytokine for being either a suppresser or promoter during tumor initiation and progression. In solid tumors, TGF-β secreted from tumor microenvironment acts as a suppresser against host immunity, like natural killer (NK) cells, to favor tumor evasion. However, besides solid tumors, the underlying mechanism of how TGF-β regulates leukemogenesis, tumor progression, immunoediting, and NK function is still not clear in detail. In this study, we found that TGF-β induced leukemia MEG-01 and U937 cells to become less sensitive to NK-92MI targeting by down-regulating CD48, a ligand for NK activating receptor 2B4, but not down-regulating other tumor-associated carbohydrate antigens (TACAs). In CD48-knockdown cells, cells responding to NK-92MI targeting displayed a phenotype of less NK susceptibility and cell conjugation. On the other hand, when NK cells were treated with TGF-β, TGF-β suppressed NK recognition, degranulation, and killing activity in time-dependent manner by regulating ICAM-1 binding capacity instead of affecting expressions of activating and inhibitory receptors. Taken together, both leukemia cells and immune NK cells could be regulated by TGF-β through suppressing leukemia cell surface CD48 to escape from host surveillance and down-regulating NK cell surface ICAM-1 binding activity to impair NK functions, respectively. Our results suggested that TGF-β had effect in leukemia similar to that observed in solid tumors but through different regulatory mechanism.

TINP1 homolog is required for planarian regeneration

The planarian flatworm is an ideal system for the study of regeneration in vivo. In this study, we focus on TINP1, which is one of the most conserved proteins in eukaryotic organisms. We found that TINP1 was expressed in parenchymal region through whole body as well as central nervous system (CNS) during the course of regeneration. RNA interference targeting DjTINP1 caused lysis defects in regenerating tissues and a decreased in cell division and expression levels of DjpiwiA and Djpcna. Furthermore, the expression levels of DjTINP1 were decreased when we inhibited the TGF-β signal by knockdown of smad4, which is the sole co-smad and has been proved to control the blastema patterning and central nervous system (CNS) regeneration in planarians. These findings suggest that DjTINP1 participate in the maintenance of neoblasts and be required for proper cell proliferation in planarians as a downstream gene of the TGF-β signal pathway.

The role of extracellular matrix stiffness in megakaryocyte and platelet development and function

The extracellular matrix (ECM) is a key acellular structure in constant remodeling to provide tissue cohesion and rigidity. Deregulation of the balance between matrix deposition, degradation, and crosslinking results in fibrosis. Bone marrow fibrosis (BMF) is associated with several malignant and nonmalignant pathologies severely affecting blood cell production. BMF results from abnormal deposition of collagen fibers and enhanced lysyl oxidase-mediated ECM crosslinking within the marrow, thereby increasing marrow stiffness. Bone marrow stiffness has been recently recognized as an important regulator of blood cell development, notably by modifying the fate and differentiation process of hematopoietic or mesenchymal stem cells. This review surveys the different components of the ECM and their influence on stem cell development, with a focus on the impact of the ECM composition and stiffness on the megakaryocytic lineage in health and disease. Megakaryocyte maturation and the biogenesis of their progeny, the platelets, are thought to respond to environmental mechanical forces through a number of mechanosensors, including integrins and mechanosensitive ion channels, reviewed here.

Platelet-Rich Plasma Derived Growth Factors Contribute to Stem Cell Differentiation in Musculoskeletal Regeneration

Stem cell treatment and platelet-rich plasma (PRP) therapy are two significant issues in regenerative medicine. Stem cells such as bone marrow mesenchymal stem cells, adipose-derived stem cells and periodontal ligament stem cells can be successfully applied in the field of tissue regeneration. PRP, a natural product isolated from whole blood, can secrete multiple growth factors (GFs) for regulating physiological activities. These GFs can stimulate proliferation and differentiation of different stem cells in injury models. Therefore, combination of both agents receives wide expectations in regenerative medicine, especially in bone, cartilage and tendon repair. In this review, we thoroughly discussed the interaction and underlying mechanisms of PRP derived GFs with stem cells, and assessed their functions in cell differentiation for musculoskeletal regeneration.

Efficacy of ALK5 inhibition in myelofibrosis

Myelofibrosis (MF) is a bone marrow disorder characterized by clonal myeloproliferation, aberrant cytokine production, extramedullary hematopoiesis, and bone marrow fibrosis. Although somatic mutations in JAK2, MPL, and CALR have been identified in the pathogenesis of these diseases, inhibitors of the Jak2 pathway have not demonstrated efficacy in ameliorating MF in patients. TGF-β family members are profibrotic cytokines and we observed significant TGF-β1 isoform overexpression in a large cohort of primary MF patient samples. Significant overexpression of TGF-β1 was also observed in murine clonal MPL^W515L megakaryocytic cells. TGF-β1 stimulated the deposition of excessive collagen by mesenchymal stromal cells (MSCs) by activating the TGF-β receptor I kinase (ALK5)/Smad3 pathway. MSCs derived from MPL^W515L mice demonstrated sustained overproduction of both collagen I and collagen III, effects that were abrogated by ALK5 inhibition in vitro and in vivo. Importantly, use of galunisertib, a clinically active ALK5 inhibitor, significantly improved MF in both MPL^W515L and JAK2^V617F mouse models. These data demonstrate the role of malignant hematopoietic stem cell (HSC)/TGF-β/MSC axis in the pathogenesis of MF, and provide a preclinical rationale for ALK5 blockade as a therapeutic strategy in MF.

Acute promyelocytic leukemia with increased bone marrow reticulin fibrosis: Description of three cases and review of the literature

Pathologic increase in bone marrow reticulin fibrosis can be present in many malignant hematopoietic diseases. In acute leukemia, one-third of patients have some degree of marrow reticulin fibrosis at presentation, which is thought to be related to cytokine release from blasts. Marrow fibrosis is particularly common in acute megakaryoblastic leukemia, while this change is rarely seen in acute promyelocytic leukemia. Six case reports of acute promyelocytic leukemia with marrow reticulin fibrosis have been described so far in the literature. Herein, we present three cases of classical acute promyelocytic leukemia with increased marrow reticulin fibrosis encountered in our institution, summarizing their clinicopathologic features, treatment, and outcome to date. Awareness of the features of acute promyelocytic leukemia with marrow reticulin fibrosis is important as it may guide treatment options.

The TGF-β/SMAD pathway is an important mechanism for NK cell immune evasion in childhood B-acute lymphoblastic leukemia

Natural killer (NK) cells are key components of the innate immune system, providing potent antitumor immunity. Here, we show that the tumor growth factor-β (TGF-β)/SMAD signaling pathway is an important mechanism for NK cell immune evasion in childhood B-acute lymphoblastic leukemia (ALL). We characterized NK cells in 50 consecutive children with B-ALL at diagnosis, end induction and during maintenance therapy compared with age-matched controls. ALL-NK cells at diagnosis had an inhibitory phenotype associated with impaired function, most notably interferon-γ production and cytotoxicity. By maintenance therapy, these phenotypic and functional abnormalities partially normalized; however, cytotoxicity against autologous blasts remained impaired. We identified ALL-derived TGF-β1 to be an important mediator of leukemia-induced NK cell dysfunction. The TGF-β/SMAD signaling pathway was constitutively activated in ALL-NK cells at diagnosis and end induction when compared with healthy controls and patients during maintenance therapy. Culture of ALL blasts with healthy NK cells induced NK dysfunction and an inhibitory phenotype, mediated by activation of the TGF-β/SMAD signaling pathway, and abrogated by blocking TGF-β. These data indicate that by regulating the TGF-β/SMAD pathway, ALL blasts induce changes in NK cells to evade innate immune surveillance, thus highlighting the importance of developing novel therapies to target this inhibitory pathway and restore antileukemic cytotoxicity.

Acute Myeloid Leukemia with Isolated Trisomy 19 Associated with Diffuse Myelofibrosis and Osteosclerosis

Primary myelofibrosis (PMF), per WHO criteria, is a clonal myeloproliferative neoplasm that usually presents with a proliferation of granulocytic and megakaryocytic lineages with an associated fibrous deposition and extramedullary hematopoiesis. The bone marrow histologic findings of this disorder are typically characterized by the presence of myeloid metaplasia with an associated reactive fibrosis, angiogenesis, and osteosclerosis. However, marked myelofibrosis is not solely confined to PMF and may also be associated with other conditions including but not limited to acute megakaryoblastic leukemias (FAB AML-M7). Here, we describe a rare case of a non-megakaryoblastic acute myeloid leukemia with marked myelofibrosis with osteosclerosis and an isolated trisomy 19. A 19-year-old male presented with severe bone pain of one week duration with a complete blood cell count and peripheral smear showing a mild anemia and occasional circulating blasts. A follow up computed tomography (CT) scan showed diffuse osteosclerosis with no evidence of hepatosplenomegaly or lymphadenopathy. Subsequently, the bone marrow biopsy showed markedly sclerotic bony trabeculae and a hypercellular marrow with marked fibrosis and intervening sheets of immature myeloid cells consistent with myeloblasts with monocytic differentiation. Importantly, these myeloblasts were negative for megakaryocytic markers (CD61 and vWF), erythroid markers (hemoglobin and E-cadherin), and lymphoid markers (CD3, CD19, and TdT). Metaphase cytogenetics showed an isolated triosomy 19 with no JAK2 V617F mutation. The patient was treated with induction chemotherapy followed by allogenic hematopoietic stem cell transplantation which subsequently resulted in a rapid resolution of bone marrow fibrosis, suggesting graft-anti-fibrosis effect. This is a rare case of a non-megakaryoblastic acute myeloid leukemia with myelofibrosis and osteosclerosis with trisomy 19 that may provide insights into the prognosis and therapeutic options of future cases.

Cancer associated fibroblasts in hematological malignancies

Tumor microenvironment plays an important role in cancer initiation and progression. In hematological malignancies, the bone marrow represents the paradigmatic anatomical site in which tumor microenvironment expresses its morphofunctional features. Among the cells participating in the composition of this microenvironment, cancer associated fibrobasts (CAFs) have received less attention in hematopoietic tumors compared to solid cancers. In this review article, we discuss the involvement of CAFs in progression of hematological malignancies and the potential targeting of CAFs in a therapeutic perspective.

The association of TGFB1 genetic polymorphisms with high myopia: a systematic review and meta-analysis

OBJECTIVE

The TGFB1 gene is among the most studied genes in high myopia due to its role in scleral remodeling. But reported findings of association on TGFB1 and high myopia are inconsistent. This present study is to evaluate the association of TGFB1 polymorphisms and high myopia.

METHODS

A comprehensive literature search was conducted on studies published up to April 5, 2015. Summary odds ratios (ORs) and 95% confidence intervals were analyzed. Heterogeneity across studies was evaluated by Cochran Q statistic test and the I(2) index. Sensitivity analyses were conducted by the approach of one-study remove to assess the influence of single study on the combined effect.

RESULTS

Eight studies were included in this study for meta-analysis. Rs1982073 was associated with high myopia in dominant model (OR=1.64; 95% CI=1.04~2.58; P<0.05), heterozygous model (OR=1.54; 95% CI=1.02~2.33; P<0.05), homozygous model (OR=1.90; 95% CI=1.01~3.55; P=0.05) and allelic model (OR=1.36; 95% CI=1.01~1.84; P=0.05). However, there was no statistical significance when Bonferroni correction was considered. Rs4803455 was associated with high myopia in recessive model (OR=0.40; 95% CI=0.25~0.64; P<0.01) and homozygous model (OR=0.42; 95% CI=0.26~0.68; P<0.01). Rs1800469 was associated with high myopia in allelic model (OR=0.78; 95% CI=0.64~0.96; P<0.05). And the associations can withstand Bonferroni correction in models mentioned above when referring to rs4803455 (P<0.01) and rs1800469 (P<0.05).

CONCLUSIONS

Meta-analysis of existing data revealed a suggestive association of TGFB1 rs1982073 and rs4803455 with high myopia.

The importance of the tissue microenvironment in hairy cell leukemia

Hairy cell leukemia (HCL) cells engage in complex cellular and molecular interactions with accessory cells, matrix proteins, and various cytokines in the bone marrow and spleen, collectively referred to as the tissue microenvironment. Chemokine receptors and adhesion molecules are critical players for homing and retention within these microenvironments. Engagement of B cell antigen receptors and CD40 on HCL cells promote survival and proliferation. In this chapter, we summarize the current knowledge about the cellular and molecular interactions between HCL cells and their supportive tissue microenvironment, and provide insight into new therapeutic approaches targeting B cell receptor signaling in HCL.

An unusual indication for splenectomy in hairy cell leukaemia: a report of three cases with persistent splenomegaly after chemoimmunotherapy

We describe three cases of relapsed hairy cell leukaemia (HCL) treated with pentostatin plus rituximab. All three achieved bone marrow complete remission but had persistent splenomegaly and hypersplenism. Because of the clinical uncertainty of its significance, they were all splenectomized. The spleen histology showed no evidence of HCL, but a five‐fold thickening of the splenic capsule and areas of fibrosis in the red pulp. This process may have contributed to the lack of elasticity and caused the persistent splenomegaly. We discuss the clinical implications for future patient management. The three patients remain in remission at 1 + , 5 +  and 9 +  years.

Fibrogenesis in Primary Myelofibrosis: Diagnostic, Clinical, and Therapeutic Implications

Primary myelofibrosis is a stem cell-derived clonal malignancy characterized by unchecked proliferation of myeloid cells, resulting in bone marrow fibrosis, osteosclerosis, and pathologic angiogenesis. Bone marrow fibrosis (BMF) plays a central role in the pathophysiology of the disease. This review describes current issues regarding BMF in primary myelofibrosis, including the pathophysiology and impact of abnormal deposition of excess collagen and reticulin fibers in bone marrow spaces, the modified Bauermeister and the European Consensus grading systems of BMF, and the prognostic impact of BMF on the overall outcome of patients with primary myelofibrosis. The impact of novel therapeutic strategies, including JAK-STAT inhibitors and allogeneic stem cell transplant, on BMF is discussed.

TGF-β signaling in the control of hematopoietic stem cells

Blood is a tissue with high cellular turnover, and its production is a tightly orchestrated process that requires constant replenishment. All mature blood cells are generated from hematopoietic stem cells (HSCs), which are the self-renewing units that sustain lifelong hematopoiesis. HSC behavior, such as self-renewal and quiescence, is regulated by a wide array of factors, including external signaling cues present in the bone marrow. The transforming growth factor-β (TGF-β) family of cytokines constitutes a multifunctional signaling circuitry, which regulates pivotal functions related to cell fate and behavior in virtually all tissues of the body. In the hematopoietic system, TGF-β signaling controls a wide spectrum of biological processes, from homeostasis of the immune system to quiescence and self-renewal of HSCs. Here, we review key features and emerging concepts pertaining to TGF-β and downstream signaling pathways in normal HSC biology, featuring aspects of aging, hematologic disease, and how this circuitry may be exploited for clinical purposes in the future.

Depletion of STAT5 blocks TEL-SYK-induced APMF-type leukemia with myelofibrosis and myelodysplasia in mice

The spleen tyrosine kinase (SYK) was identified as an oncogenic driver in a broad spectrum of hematologic malignancies. The in vivo comparison of three SYK containing oncogenes, SYK(wt), TEL-SYK and IL-2-inducible T-cell kinase (ITK)-SYK revealed a general myeloexpansion and the establishment of three different hematologic (pre)diseases. SYK(wt) enhanced the myeloid and T-cell compartment, without leukemia/lymphoma development. ITK-SYK caused lethal T-cell lymphomas and the cytoplasmic TEL-SYK fusion induced an acute panmyelosis with myelofibrosis-type acute myeloid leukemia (AML) with up to 50% immature megakaryoblasts infiltrating bone marrow, spleen and liver, additional MPN features (myelofibrosis and granulocyte expansion) and MDS stigmata with megakaryocytic and erythroid dysplasia. LKS cells were reduced and all subsets (LT/ST/MPP) showed reduced proliferation rates. SYK inhibitor treatment (R788) of diseased TEL-SYK mice reduced leukocytosis, spleen and liver infiltration, enhanced the hematocrit and prolonged survival time, but could not significantly reduce myelofibrosis. Stat5 was identified as a major downstream mediator of TEL-SYK in vitro as well as in vivo. Consequently, targeted deletion of Stat5 in vivo completely abrogated TEL-SYK-induced AML and myelofibrosis development, proving Stat5 as a major driver of SYK-induced transformation. Our experiments highlight the important role of SYK in AML and myelofibrosis and prove SYK and STAT5 inhibitors as potent treatment options for those diseases.

Update on the biology and treatment options for hairy cell leukemia

Hairy cell leukemia (HCL) is an uncommon chronic leukemia of mature B cells. Leukemic B cells of HCL exhibit a characteristic morphology and immunophenotype and coexpress multiple clonally related immunoglobulin isotypes. Precise diagnosis and detailed workup is essential, because the clinical profile of HCL can closely mimic that of other chronic B-cell lymphoproliferative disorders that are treated differently. Variants of HCL, such as HCLv and VH4-34 molecular variant, vary in the immunophenotype and specific VH gene usage, and have been more resistant to available treatments. On the contrary, classic HCL is a highly curable disease. Most patients show an excellent long-term response to treatment with single-agent cladribine or pentostatin, with or without the addition of an anti-CD20 monoclonal antibody such as rituximab. However, approximately 30-40 % of patients with HCL relapse after therapy; this can be treated with the same purine analogue that was used for the initial treatment. Advanced molecular techniques have identified distinct molecular aberrations in the Raf/MEK-ERK pathway and BRAF (V600E) mutations that drive the proliferation and survival of HCL B cells. Currently, research in the field of HCL is focused on identifying novel therapeutic targets and potential agents that are safe and can universally cure the disease. Ongoing and planned clinical trials are assessing various treatment strategies, such as the combination of purine analogues and various anti-CD20 monoclonal antibodies, recombinant immunotoxins targeting CD22 (e.g., moxetumomab pasudotox), BRAF inhibitors, such as vemurafenib, and B-cell receptor signaling inhibitors, such as ibrutinib, which is a Bruton's tyrosine kinase inhibitor. This article provides an update of our current understanding of the pathophysiology of HCL and the treatment options available for patients with classic HCL. Discussion of variant forms of HCL is beyond the scope of this manuscript.

Involvement of TGFβ1 in autocrine regulation of proplatelet formation in healthy subjects and patients with primary myelofibrosis

Megakaryocytes release platelets into the bloodstream by elongating proplatelets. In this study, we showed that human megakaryocytes constitutively release Transforming Growth Factor β1 and express its receptors. Importantly, Transforming Growth Factor β1 downstream signaling, through SMAD2/3 phosphorylation, was shown to be active in megakaryocytes extending proplatelets, indicating a type of autocrine stimulation on megakaryocyte development. Furthermore, inactivation of Transforming Growth Factor β1 signaling, by the receptor inhibitors SB431542 and Stemolecule ALK5 inhibitor, determined a significant decrease in proplatelet formation. Recent studies indicated a crucial role of Transforming Growth Factor β1 in the pathogenesis of primary myelofibrosis. We demonstrated that primary myelofibrosis-derived megakaryocytes expressed increased levels of bioactive Transforming Growth Factor β1; however, higher levels of released Transforming Growth Factor β1 did not lead to enhanced activation of downstream pathways. Overall, these data propose Transforming Growth Factor β1 as a new element in the autocrine regulation of proplatelet formation in vitro. Despite the increase in Transforming Growth Factor β1 this mechanism seems to be preserved in primary myelofibrosis.

Synergism between fibronectin and transforming growth factor-β1 in the production of substance P in monocytes of patients with myelofibrosis

Substance P (SP), also considered a proinflammatory cytokine, as well as others such as transforming growth factor-β1 (TGF-β1) and interleukin-1 (IL-1), and the extracellular matrix protein fibronectin (FN) have been associated with the pathophysiology of myelofibrosis. SP is encoded by the TAC1 gene. The relationships among SP, TGF-β1, IL-1 and FN are poorly understood. This study determined the mechanisms for concomitant production of IL-1, TGF-β1 and SP and also determined the synergistic role of FN in SP release. Enzyme-linked immunosorbent assay (ELISA) indicated increased levels of SP and TGF-β1 in the blood of patients with myelofibrosis. Monocytes, shown to be activated in patients with bone marrow (BM) fibrosis, expressed the TAC1 gene for SP release, in a nuclear factor-κB (NFκB)-dependent manner. Reporter gene assay with the 5' regulatory region of TAC1 indicated its expression by high levels of FN and TGF-β1. Immunohistochemical studies of paraffin-embedded BM biopsies from patients with myelofibrosis, and age-matched controls without fibrosis, indicated co-localization of SP and its receptor neurokinin-1 (NK1). In summary, myelofibrotic monocytes have autocrine loops that stimulate the release of SP and TGF-β1, and that are potentiated by fibronectin. The FN-mediated induction of SP in turn stimulates monocytes through autostimulation by NK1 receptors. These findings, combined with those of previous studies, demonstrate an adhesion-mediated NFκB/IL-1/TGF-β1 axis that can be initiated by increased FN in patients with myelofibrosis for the production of SP. These findings show how TGF-β1 and SP production are coupled, and suggest new therapeutic targets to reverse immune-mediated fibrosis.

TGF-β - an excellent servant but a bad master

The transforming growth factor (TGF-β) family of growth factors controls an immense number of cellular responses and figures prominently in development and homeostasis of most human tissues. Work over the past decades has revealed significant insight into the TGF-β signal transduction network, such as activation of serine/threonine receptors through ligand binding, activation of SMAD proteins through phosphorylation, regulation of target genes expression in association with DNA-binding partners and regulation of SMAD activity and degradation. Disruption of the TGF-β pathway has been implicated in many human diseases, including solid and hematopoietic tumors. As a potent inhibitor of cell proliferation, TGF-β acts as a tumor suppressor; however in tumor cells, TGF-β looses anti-proliferative response and become an oncogenic factor. This article reviews current understanding of TGF-β signaling and different mechanisms that lead to its impairment in various solid tumors and hematological malignancies.

Detection of BRAF mutations in patients with hairy cell leukemia and related lymphoproliferative disorders

Hairy cell leukemia has been shown to be strongly associated with the BRAF V600E mutation. We screened 59 unenriched archived bone marrow aspirate and peripheral blood samples from 51 patients with hairy cell leukemia using high resolution melting analysis and confirmatory Sanger sequencing. The BRAF V600E mutation was detected in 38 samples (from 36 patients). The BRAF V600E mutation was detected in all samples with disease involvement above the limit of sensitivity of the techniques used. Thirty-three of 34 samples from other hematologic malignancies were negative for BRAF mutations. A BRAF K601E mutation was detected in a patient with splenic marginal zone lymphoma. Our data support the recent finding of a disease defining point mutation in hairy cell leukemia. Furthermore, high resolution melting with confirmatory Sanger sequencing are useful methods that can be employed in routine diagnostic laboratories to detect BRAF mutations in patients with hairy cell leukemia and related lymphoproliferative disorders.

The role of Smad signaling in hematopoiesis and translational hematology

Hematopoietic stem cells (HSCs) reside in the bone marrow (BM) of adult individuals and function to produce and regenerate the entire blood and immune system over the course of an individual's lifetime. Historically, HSCs are among the most thoroughly characterized tissue-specific stem cells. Despite this, the regulation of fate options, such as self-renewal and differentiation, has remained elusive, partly because of the expansive plethora of factors and signaling cues that govern HSC behavior in vivo. In the BM, HSCs are housed in specialized niches that dovetail the behavior of HSCs with the need of the organism. The Smad-signaling pathway, which operates downstream of the transforming growth factor-β (TGF-β) superfamily of ligands, regulates a diverse set of biological processes, including proliferation, differentiation and apoptosis, in many different organ systems. Much of the function of Smad signaling in hematopoiesis has remained nebulous due to early embryonic lethality of most knockout mouse models. However, recently new data have been uncovered, suggesting that the Smad-signaling circuitry is intimately linked to HSC regulation. In this review, we bring the Smad-signaling pathway into focus, chronicling key concepts and recent advances with respect to TGF-β-superfamily signaling in normal and leukemic hematopoiesis.

The microenvironment in hairy cell leukemia: pathways and potential therapeutic targets

Hairy cell leukemia (HCL) cells accumulate and proliferate in the spleen and the bone marrow. In these tissue compartments, HCL cells interact with accessory cells, matrix proteins, and various cyctokines, collectively referred to as the 'microenvironment.' Surface receptors expressed on HCL cells and respective stromal ligands are critical for this cross-talk between HCL cells and the microenvironment. Chemokine receptors, adhesion molecules (integrins, CD44), the B cell antigen receptor (BCR), and CD40, expressed on the HCL cells, are likely to be critical for homing, retention, survival, and expansion of the neoplastic B cells. Some of these pathways are now targeted in first clinical trials in other mature B-cell malignancies. We summarize key aspects of the cellular and molecular interactions between HCL cells and their microenvironment. Also, we outline future prospects for therapeutic targeting of the microenvironment in HCL, focusing on CXCR4 and kinase inhibitors (Syk, Btk, phosphatidylinositol 3-kinase [PI3K]) that target B cell receptor signaling.

Platelet-rich plasma (PRP) impairs the craniofacial bone repair associated with its elevated TGF-β levels and modulates the co-expression between collagen III and α-smooth muscle actin

Transforming growth factor-β (TGF-β) is considered the main inducer of both the α-smooth muscle actin (α-SMA) phenotype and collagen synthesis and deposition and plays a significant role in the tissue repair and the development of fibrosis. Since the PRP constitutes an important source of TGF-β and its efficacy on the craniofacial bone repair remains controversy, the aim of this study was to evaluate the effect of PRP in the presence of levels of TGF-β on PRP samples, as well as in the presence of collagen III and α-SMA+ cells, while comparing these results by means of a histomorphometric analysis of the bone matrix and fibrous deposition on the bone repair. Four bone defects of 16 mm(2) were created on the calvarium of 21 rabbits. The surgical defects were treated with either particulate autograft, particulate autograft mixed with PRP and PRP alone. Animals were euthanized at 15, 30, and 45 days postoperative. Histomorphometric and immunohistochemical analyses were performed to assess repair time, as well as the expression of collagen III, and α-SMA. The histomorphometric results demonstrated intensive deposition of fibrous tissue while hinder bone deposition occurred in PRP groups. These results coincided with higher values of the TGF-β on the PRP sample, also larger occurrence of diffuse collagen III deposition and higher presence of α-SMA+ cells spread among the fibrous tissue. Thus, the higher levels of TGF-β associated with the both expression of collagen III and α-SMA on defect treated with PRP suggest that its biomaterial induce an effect that can be considered similarly to a fibroproliferative disorder.

2D difference gel electrophoresis analysis of different time points during the course of neoplastic transformation of human mammary epithelial cells

Cell culture models of oncogenesis that use cellular reprogramming to generate a neoplastic cell from a normal cell provide one of the few opportunities to study the early stages of breast cancer development. Human mammary epithelial cells (HMECs) were induced to undergo a neoplastic transformation using defined genetic elements to generate transformed HMECs (THMECs). To identify proteins that displayed significantly different levels of abundance at three consecutive time points in oncogenesis over an 80 day period, protein extracts were analyzed by two-dimensional difference gel electrophoresis (2D-DIGE). Nine proteins were found to be significantly different in abundance: keratin 1, keratin 7, heat shock protein 4A-like, t-complex protein 1, stathmin, gelsolin, FK506 binding protein 5, ribosomal protein P0, and maspin. Keratin 7 and maspin displayed a linear down-regulation over 80 days. All of these proteins have been shown to be involved in the maintenance of a metastatic state including cytoskeletal modifications and motility. We conclude that, following neoplastic induction, THMECs display an early and progressive increase in metastatic potential. Further investigations into the function and regulatory mechanisms of these proteins will provide an unparalleled understanding of the initial states through which a breast cancer cell transitions following acquisition of the genetic abnormalities required for oncogenesis.

The biology of hairy-cell leukaemia

PURPOSE OF REVIEW

The biology of hairy-cell leukaemia is reviewed, focussing first on the hairy cell itself and then on its interactions with the microenvironment.

RECENT FINDINGS

Hairy cells are highly activated clonal B cells related to memory cells, normally resident in the marginal zone of the spleen. Their activation results from multiple stimuli arising from the microenvironment, autocrine cytokines and the still unknown transforming oncogenic event(s) responsible for the disease. Protein kinase Cepsilon is a central player in the activation process.

SUMMARY

The activation of hairy cells makes them unusually sensitive to interferon and nucleosides. Future important research topics include characterization of the oncogenic events responsible for the disease and for its associated differentiation block.

Reconstitution of PTEN activity by CK2 inhibitors and interference with the PI3-K/Akt cascade counteract the antiapoptotic effect of human stromal cells in chronic lymphocytic leukemia

Evidence suggests that tumor microenvironment is critically involved in supporting survival of chronic lymphocytic leukemia (CLL) cells. However, the molecular mechanisms of this effect and the clinical significance are not fully understood. We applied a microenvironment model to explore the interaction between CLL cells and stromal cells and to elucidate the role of phosphatidylinositol 3 kinase (PI3-K)/Akt/phosphatase and tensin homolog detected on chromosome 10 (PTEN) cascade in this process and its in vivo relevance. Primary human stromal cells from bone marrow, lymph nodes, and spleen significantly inhibited spontaneous apoptosis of CLL cells. Pan-PI3-K inhibitors (LY294002, wortmannin, PI-103), isotype-specific inhibitors of p110α, p110β, p110γ, and small interfering RNA against PI3-K and Akt1 counteracted the antiapoptotic effect of the stromal cells. Induction of apoptosis was associated with a decrease in phosphatidylinositol-3,4,5-triphosphate, PI3-K-p85, and dephosphorylation of phosphatidylinositol-dependent kinase-1 (PDK-1), Akt1, and PTEN. Freshly isolated peripheral blood mononuclear cells from patients with CLL (n = 44) showed significantly higher levels of phosphorylated Akt1, PDK-1, PTEN, and CK2 than healthy persons (n = 8). CK2 inhibitors (4,5,6,7-tetrabromo-1H-benzotriazole, apigenin, and 5,6-dichloro-1-β-D-ribofuranosylbenzimidazol) decreased phosphorylation of PTEN and Akt, induced apoptosis in CLL cells, and enhanced the response to fludarabine. In conclusion, bone marrow microenvironment modulates the PI3-K/Akt/PTEN cascade and prevents apoptosis of CLL cells. Combined inhibition of PI3-K/Akt and recovery of PTEN activity may represent a novel therapeutic concept for CLL.

Efficacy of romiplostim in patients with chronic immune thrombocytopenic purpura: a double-blind randomised controlled trial

BACKGROUND

Chronic immune thrombocytopenic purpura (ITP) is characterised by accelerated platelet destruction and decreased platelet production. Short-term administration of the thrombopoiesis-stimulating protein, romiplostim, has been shown to increase platelet counts in most patients with chronic ITP. We assessed the long-term administration of romiplostim in splenectomised and non-splenectomised patients with ITP.

METHODS

In two parallel trials, 63 splenectomised and 62 non-splenectomised patients with ITP and a mean of three platelet counts 30x10(9)/L or less were randomly assigned 2:1 to subcutaneous injections of romiplostim (n=42 in splenectomised study and n=41 in non-splenectomised study) or placebo (n=21 in both studies) every week for 24 weeks. Doses of study drug were adjusted to maintain platelet counts of 50x10(9)/L to 200x10(9)/L. The primary objectives were to assess the efficacy of romiplostim as measured by a durable platelet response (platelet count > or =50x10(9)/L during 6 or more of the last 8 weeks of treatment) and treatment safety. Analysis was per protocol. These studies are registered with ClinicalTrials.gov, numbers NCT00102323 and NCT00102336.

FINDINGS

A durable platelet response was achieved by 16 of 42 splenectomised patients given romplostim versus none of 21 given placebo (difference in proportion of patients responding 38% [95% CI 23.4-52.8], p=0.0013), and by 25 of 41 non-splenectomised patients given romplostim versus one of 21 given placebo (56% [38.7-73.7], p<0.0001). The overall platelet response rate (either durable or transient platelet response) was noted in 88% (36/41) of non-splenectomised and 79% (33/42) of splenectomised patients given romiplostim compared with 14% (three of 21) of non-splenectomised and no splenectomised patients given placebo (p<0.0001). Patients given romiplostim achieved platelet counts of 50x10(9)/L or more on a mean of 13.8 (SE 0.9) weeks (mean 12.3 [1.2] weeks in splenectomised group vs 15.2 [1.2] weeks in non-splenectomised group) compared with 0.8 (0.4) weeks for those given placebo (0.2 [0.1] weeks vs 1.3 [0.8] weeks). 87% (20/23) of patients given romiplostim (12/12 splenectomised and eight of 11 non-splenectomised patients) reduced or discontinued concurrent therapy compared with 38% (six of 16) of those given placebo (one of six splenectomised and five of ten non-splenectomised patients). Adverse events were much the same in patients given romiplostim and placebo. No antibodies against romiplostim or thrombopoietin were detected.

INTERPRETATION

Romiplostim was well tolerated, and increased and maintained platelet counts in splenectomised and non-splenectomised patients with ITP. Many patients were able to reduce or discontinue other ITP medications. Stimulation of platelet production by romiplostim may provide a new therapeutic option for patients with ITP.

Bone marrow fibrosis: pathophysiology and clinical significance of increased bone marrow stromal fibres

In bone marrow biopsies, stromal structural fibres are detected by reticulin and trichrome stains, routine stains performed on bone marrow biopsy specimens in diagnostic laboratories. Increased reticulin staining (reticulin fibrosis) is associated with many benign and malignant conditions while increased trichrome staining (collagen fibrosis) is particularly prominent in late stages of severe myeloproliferative diseases or following tumour metastasis to the bone marrow. Recent evidence has shown that the amount of bone marrow reticulin staining often exhibits no correlation to disease severity, while the presence of type 1 collagen, as detected by trichrome staining, is often associated with more severe disease and a poorer prognosis. It was originally thought that increases in bone marrow stromal fibres themselves contributed to the haematopoietic abnormalities seen in certain diseases, but recent studies suggest that these increases are a result of underlying cellular abnormalities rather than a cause. A growing body of evidence suggests that increased deposition of bone marrow stromal fibres is mediated by transforming growth factor-beta and other factors elaborated by megakaryocytes, but it is likely that other cells, cytokines and growth factors are also involved. This suggests new avenues for investigation into the pathogenesis of various disorders associated with increased bone marrow stromal fibres.

Effect of fibroblast growth factor 2 on stromal cell-derived factor 1 production by bone marrow stromal cells and hematopoiesis

BACKGROUND

Reduction of intramedullary hematopoiesis and the development of myelofibrosis and splenic hematopoiesis are frequent complications of clonal myeloid disorders that cause severe morbidity and death and present a therapeutic challenge. However, the pathogenesis of these complications is still unknown. We evaluated the effect of fibroblast growth factor 2 (FGF-2), the level of which is elevated in patients with clonal myeloid disorders, on bone marrow stromal cell expression of stromal cell-derived factor 1 (SDF-1), a chemokine that is essential for normal hematopoiesis.

METHODS

Reverse transcription-polymerase chain reaction analysis, immunoblot analysis, and enzyme-linked immunosorbent assays were used to examine effects of human recombinant FGF-2 exposure on SDF-1 expression in mouse stromal MS-5 and S-17 cells. Cocultures of human CD34-positive peripheral blood stem cells or mouse pre-B DW34 cells with mouse stromal cells were used to characterize the functional relevance of the effects of FGF-2 on SDF-1 expression. The in vivo hematologic effects of FGF-2 were determined by systemic administration to mice (n = 10). All statistical tests were two-sided.

RESULTS

FGF-2 reduced constitutive SDF-1 mRNA expression and secretion in stromal cells (SDF-1 levels in supernatants: MS-5 cells cultured for 3 days in medium only versus in medium with FGF-2, 95.4 ng/mL versus 22.2 ng/mL, difference = 73.2 ng/mL, 95% confidence interval [CI] = 60.52 to 85.87 ng/mL; P = .002, two-sided Student's t test; S-17 cultured in medium only versus in medium with FGF-2, 203.53 ng/mL versus 32.36 ng/mL, difference = 171.17 ng/mL, 95% CI = 161.8 to 180.6 ng/mL; P<.001). These effects of FGF-2 were reversible. FGF-2 compromised stromal cell support of the growth and survival of pre-B DW34 and myeloid lineage cells, and these effects were reversed in part by exogenous recombinant SDF-1alpha (rSDF-1alpha) (DW34 pre-B cells recovery on S-17 stromal cells, expressed as a percentage of DW34 cells recovered from medium only: with FGF-2 versus without FGF-2, 27.6% versus 100%, difference = 72.4%, 95% CI = 45.34% to 99.51%, P = .008; with FGF-2 plus rSDF1 versus with FGF-2 only, 60.3% versus 27.6%, difference = 32.7%, 95% CI = 9.35% to 56.08%, P = .034; fold increase in number of myeloid lineage cells after culture on S-17 stromal cells: with FGF-2 versus without FGF-2, 0.25-fold versus 3.8-fold, difference = 3.55-fold, 95% CI = 2.66- to 4.44-fold, P<.001; recovery of myeloid cells on S-17 stromal cells, expressed as a percentage of myeloid cells recovered from medium only: FGF-2 plus rSDF-1alpha versus FGF-2 only, 76.5% versus 32.4%, difference = 44.1%, 95% CI = 32.58% to 55.68%, P<.001). Administration of FGF-2 to mice reversibly reduced bone marrow levels of SDF-1 and cellularity and induced immature myeloid cell mobilization, extramedullary hematopoiesis, and splenomegaly.

CONCLUSIONS

Systemic administration of FGF-2 in mice disrupts normal bone marrow hematopoiesis in part through reduced expression of SDF-1. Thus, endogenous FGF-2 may represent a potential therapeutic target in clonal myeloid disorders characterized by bone marrow failure.

The gray platelet syndrome: Clinical spectrum of the disease

The gray platelet syndrome (GPS) is a rare inherited disorder of the megakaryocyte (MK) lineage. Thrombocytopenia and enlarged platelets are associated with a specific absence of alpha-granules and their contents. GPS patients exhibit much heterogeneity both in bleeding severity and in their response to platelet function testing. A unique feature is that proteins endogenously synthesised by megakaryocytes (MK) or endocytosed by MK or platelets fail to enter into the secretable storage pools that characterise alpha-granules of normal platelets. Although the molecular basis of the disease is unknown, evidence suggests that alpha-granules simply fail to mature during MK differentiation. One result is a continued leakage of growth factors and cytokines into the marrow causing myelofibrosis. While for some patients platelet function may be only moderately affected, for others thrombin and/or collagen-induced platelet aggregation is markedly modified and an acquired lack of the GPVI collagen receptor has been reported. In this review, we document the clinical and molecular heterogeneity in GPS, a unique disease of the biogenesis of platelet alpha-granules and of the storage of growth factors and secretable proteins.

Pathogenesis of myelofibrosis with myeloid metaplasia: Insight from mouse models

Myelofibrosis with myeloid metaplasia or idiopathic myelofibrosis is a myeloproliferative disease. It is known to be a stem-cell disorder that leads to a secondary and reactive stromal reaction in the bone marrow microenvironment that is responsible for impaired haematopoiesis. Although progress has been made in the elucidation of the pathogenesis of idiopathic myelofibrosis, lack of suitable models has limited our understanding of the pathology. The aim of this chapter is to address recent inferred new insights in mouse models into the pathogenesis of osteomyelofibrosis. These insights outline the role of transforming growth factor-beta1 and osteoprotegerin in the promotion of myelofibrosis and osteosclerosis, respectively, paying special regard to the role of abnormal megakaryocyte proliferation and maturation.

Nsa2 is an unstable, conserved factor required for the maturation of 27 SB pre-rRNAs

In Saccharomyces cerevisiae, a large variety of pre-ribosomal factors have been identified recently, a number of which are still of unknown function. The essential pre-ribosomal 30-kDa protein, Nsa2, was characterized as one of the most conserved proteins from yeast to human. We show here that the expression of the human orthologue TINP1 complements the repression of NSA2 in yeast. Nsa2 was co-purified in several pre-ribosomal complexes and found to be essential for the large ribosomal subunit biogenesis. Like several other factors of the pre-60 S particles, the absence of Nsa2 correlated with a decrease in the 25 S and 5.8 S ribosomal RNA levels, and with an accumulation of 27 SB pre-ribosomal RNA intermediates. We show that Nsa2 is a functional partner of the putative GTPase Nog1. In the absence of Nsa2, Nog1 was still able to associate with pre-ribosomal complexes blocked in maturation. In contrast, in the absence of Nog1, Nsa2 disappeared from pre-60 S complexes. Indeed, when ribosome biogenesis was blocked upstream of Nsa2, this short half-lived protein was largely depleted, suggesting that its cellular levels are tightly regulated.

Evolving concepts in the pathogenesis of hairy-cell leukaemia

Hairy-cell leukaemia (HCL) has long been recognized as distinct from other chronic B-cell malignancies, but several questions remain unanswered. What is the HCL cell of origin? Why does HCL lack the hallmarks of most mature B-cell tumours (for example, chromosomal translocations and consistent lymph node involvement) and show unique features like 'hairy' morphology and bone-marrow fibrosis? Gene-expression profiling and other studies have recently provided new insights into HCL biology and have the potential to affect clinical practice.

Effect of combined spa-exercise therapy on circulating TGF-β1 levels in patients with ankylosing spondylitis

BACKGROUND

Ankylosing spondylitis (AS) is a chronic inflammatory disease of the axial joints with no satisfactory therapy. Reduction of joint pain has been reported after a course of therapy at a spa, Gasteiner Heilstollen, in Badgastein in Austria. The mechanism underlying this beneficial effect is not clearly understood and objective evidence for the biological response to therapy is lacking. The aim of this study was to find evidence for a biological response to speleotherapy in patients with AS and to study the involvement of the antiinflammatory cytokine TGF-beta1 in this response.

PATIENTS AND METHODS

83 patients with AS were treated in Badgastein for 3-4 weeks. Therapy included active exercises, hyperthermia and exposure to low doses of radon in a former mine. Response to therapy was assessed from measurement of morning pain and immunoassay of serum levels of TGF-beta1 before and after therapy. Ten AS patients who received conventional therapy and 10 patients with low back pain (LBP) served as controls.

RESULTS

A significant increase in TGF-beta1 (total and active) was found in AS patients after spa therapy. Mean concentration of total TGF-beta1 increased from 28,715 pg/ml to 43,136 pg/ml, (P<0.01) and active TGF-beta1 increased from 77 pg/ml to 1096 pg/ml (P<0.001). When the AS patients were divided into two groups according to pain reduction, group 1 (decrease in morning pain, responders: n=46) exhibited a 17-fold increase of active TGF-beta1 levels (96 pg/ml to 1654 pg/ml, P<0.0001) whereas group 2 (no change or an increase in morning pain: nonresponders: n=37), showed only 7-fold increase (53 pg/ml to 402 pg/ml, P<0.01). There was a moderate increase in active TGF-beta1 from 31 pg/ml to 42 pg/ml (P<0.05) in patients with LBP and no significant change was observed in the patients treated with conventional therapy.

CONCLUSION

These results demonstrate a significant increase in circulating TGF-beta1 in patients with AS after the combined spa-exercise therapy in Badgastein. The results also provide evidence for a biological response to speleotherapy and suggest that TGF-beta, through its antiinflammatory function, may play a role in this response.