5q-syndromes

Myelodysplastic syndrome (MDS) is a common hematological disease in patients over sixty. Despite intensive research, the therapy of this heterogeneous blood disease is complicated. In recent years, two new therapeutic approaches have been proposed: immunomodulation and demethylation therapy. Immunomodulation therapy with lenalidomide represents a meaningful advance in the treatment of anemic patients, specifically those with 5q- aberrations. As much as 60-70% of patients respond and achieve transfusion independence...

OBJECTIVE: To establish a nested case-control study cohort in myelodysplastic syndrome (MDS) patients and investigate the clinical characteristics, WHO subtype and risk factors associated with MDS evolution to leukemia of this cohort. METHODS: All patients, ≥18 years of age, provided by 24 Shanghai hospitals with initial clinical findings consistent with a hematopoietic abnormality between June 2003 and April 2007, were the candidates for inclusion in this study...

In genomic deletions, gene haploinsufficiency might directly configure a specific disease phenotype. Nevertheless, in some cases no functional association can be identified between haploinsufficient genes and the deletion-associated phenotype. Transcripts can act as microRNA sponges. The reduction of transcripts from the hemizygous region may increase the availability of specific microRNAs, which in turn may exert in-trans regulation of target genes outside the deleted region, eventually contributing to the phenotype...

BACKGROUND: Lenalidomide has demonstrated remarkable efficacy for therapy of lower-risk myelodysplastic syndromes (MDS) associated with 5q(-). The present evaluation aimed to describe the characteristics and outcomes of low-risk MDS patients treated with lenalidomide in Austria. PATIENTS AND METHODS: For this retrospective, multicenter, observational analysis of MDS patients who received lenalidomide, data were collected at various hospitals in Austria over a period of 3 years...

Dysregulation of ribosome biogenesis causes human diseases, such as Diamond-Blackfan anemia, del (5q-) syndrome and bone marrow failure. However, the mechanisms of blood disorders in these diseases remain elusive. Through genetic mapping, molecular cloning and mechanism characterization of the zebrafish mutant cas002, we reveal a novel connection between ribosomal dysfunction and excessive autophagy in the regulation of hematopoietic stem/progenitor cells (HSPCs). cas002 carries a recessive lethal mutation in kri1l gene that encodes an essential component of rRNA small subunit processome...

Mutations of CSNK1A1, a gene mapping to the commonly deleted region of the 5q- syndrome, have been recently described in patients with del(5q) myelodysplastic syndromes (MDS). Haploinsufficiency of Csnk1a1 in mice has been shown to result in β-catenin activation and expansion of haematopoietic stem cells (HSC). We have screened a large cohort of 104 del(5q) MDS patients and have identified mutations of CSNK1A1 in five cases (approximately 5%). We have shown up-regulation of β-catenin target genes in the HSC of patients with del(5q) MDS...

The 5q- syndrome is the most distinct of the myelodysplastic syndromes (MDS) and patients with this disorder have a deletion of chromosome 5q [del(5q)] as the sole karyotypic abnormality. Several genes mapping to the commonly deleted region of the 5q- syndrome have been implicated in disease pathogenesis in recent years. Haploinsufficiency of the ribosomal gene RPS14 has been shown to cause the erythroid defect in the 5q- syndrome. Loss of the microRNA genes miR-145 and miR-146a has been associated with the thrombocytosis observed in 5q- syndrome patients...

A specific type of myelodysplastic syndrome (MDS) is associated with isolated deletion on the long arm of chromosome 5, i.e., 5q-syndrome (del(5q)). The treatment approaches for MDS del(5q) include the immunomodulating drug lenalidomide (LEN). Thirteen MDS del(5q) patients were included in this study. We found elevated activities of lactate dehydrogenase (LDH) and matrix metalloproteinase 9 (MMP-9) in the blood plasma of MDS del(5q) patients as compared with healthy controls. This was stabilized to control values after LEN treatment...

Recent studies have greatly illuminated the genomic landscape of the myelodysplastic syndromes (MDS), and the pace of discovery is accelerating. The most common mutations found in MDS occur in genes involved in RNA splicing (including SF3B1, SRSF2, U2AF1, and ZRSR2) and epigenetic modification (including TET2, ASXL1, and DNMT3A). The identification of spliceosome mutations in approximately half of all patients with MDS implicates abnormalities of RNA splicing, a pathway not previously known as a target for mutation, in the MDS pathogenesis...

While Polycomb group protein Bmi1 is important for stem cell maintenance, its role in lineage commitment is largely unknown. We have identified Bmi1 as a novel regulator of erythroid development. Bmi1 is highly expressed in mouse erythroid progenitor cells and its deficiency impairs erythroid differentiation. BMI1 is also important for human erythroid development. Furthermore, we discovered that loss of Bmi1 in erythroid progenitor cells results in decreased transcription of multiple ribosomal protein genes and impaired ribosome biogenesis...

Patients affected by monoclonal gammopathy of undetermined significance (MGUS) very rarely develop a myelodysplastic syndrome (MDS). However, it was also demonstrated that MGUS patients had a significantly increased risk of developing MDS compared to the general population. We report a case of 5q-syndrome following a MGUS IgMk with mutation of MYD88 L256P. To our knowledge, this is the first case of del(5q) MDS following MGUS IgMk with the MYD88 L256P mutation in which there is coexistence of the markers of the two clonal diseases, but as an expression of distinct pathological features...

Haploinsufficiency of ribosomal proteins (RPs) and upregulation of the tumour suppressor TP53 have been shown to be the common basis for the anaemia observed in Diamond Blackfan anaemia and 5q- myelodysplastic syndrome. We previously demonstrated that treatment with L-Leucine resulted in a marked improvement in anaemia in disease models. To determine if the L-Leucine effect was Tp53-dependent, we used antisense MOs to rps19 and rps14 in zebrafish; expression of tp53 and its downstream target cdkn1a remained elevated following L-leucine treatment...

OBJECTIVE: The CXXC domain protein 4 (CXXC4) functions as a negative regulator of Wnt signaling and also regulates expression of the ten-eleven translocation 2 (TET2) protein for DNA methylation. This study detected levels of CXXC4 and TET2 mRNA to determine their association with survival of patients with myelodysplastic syndrome (MDS). METHODS: Levels of TET2 and CXXC4 mRNA were analyzed in bone marrow samples from 154 MDS patients and 50 control subjects using qRT-PCR and subsequently associated these levels with clinicopathological characteristics and survival of MDS patients...

No abstract text is available yet for this article.

Secreted protein acidic and rich in cysteine (SPARC) plays key roles in erythropoiesis; haploinsufficiency of SPARC is implicated in the progression of the 5q- syndrome. However, the role of SPARC in other subtypes of myelodysplastic syndrome (MDS) is not fully understood, particularly in the del(5q) type with a complex karyotype, which has a high risk to transform into acute myeloid leukemia (AML). In the present study, we investigated the role of SPARC in the proliferation and apoptosis of SKM-1 cells, an acute myeloid leukemia cell line transformed from an MDS cell line...

Heterozygous, interstitial deletions of chromosome 5q are the most common cytogenetic abnormality in myelodysplastic syndromes (MDS). This chromosomal abnormality is associated with a consistent clinical phenotype, the 5q- syndrome, in a subset of patients, and therapeutic sensitivity to the drug lenalidomide. No genes on chromosome 5q undergo recurrent homozygous inactivation in MDS patients. Instead, haploinsufficiency for key genes powerfully alters hematopoiesis, leading to the MDS phenotype in patients with del(5q)...

BACKGROUND: Studies with long-term follow-up of patients with myelodysplastic syndromes (MDS) based on data from nationwide population-based cancer registries are lacking. We conducted a nationwide population-based study to assess trends in incidence, initial treatment and survival in MDS patients diagnosed in the Netherlands from 2001 to 2010. METHODS: We identified 5144 MDS patients (median age, 74 years) from the Netherlands Cancer Registry (NCR). The NCR only includes MDS cases that were confirmed by bone marrow examinations...

BACKGROUND: myelodysplastic syndromes (MDS) are a heterogeneous group of hematopoietic clonal disorders. So, prognostic variables are important to separate patients with a similar biology and clinical outcome. We compared the importance of risk stratification in primary MDS of IPSS and WPSS with the just described revision of IPSS (IPSS-R), and examined if variables obtained by bone marrow immunophenotyping could add prognostic information to any of the scores. METHODS: In this prospective study of 101 cases of primary MDS we compared the relation of patients' overall survival with WHO types, IPSS, IPSS-R, WPSS and phenotypic abnormalities of hematopoietic precursors...

OBJECTIVES: Ribosomal protein S14 (RPS14) plays a key role in erythropoiesis and causes p53 activation in 5q- syndrome. However, the oncogenic potential of RPS14 is not understood in leukemia and high-risk myelodysplastic syndrome (MDS). Here, we investigated the changes of proliferation and apoptosis of SKM-1, an acute myeloid leukemia (MDS/AML) cell line transformed from MDS, and explored the role of RPS14 in them. METHODS: SKM-1 cells were transfected with recombined lentiviral vector shRPS14...

Classical 5q- syndrome is an acquired macrocytic anemia of the elderly. Similar to Diamond Blackfan anemia (DBA), an inherited red cell aplasia, the bone marrow is characterized by a paucity of erythroid precursors. RPS14 deletions in combination with other deletions in the region have been implicated as causative of the 5q- syndrome phenotype. We asked whether smaller, less easily detectable deletions could account for a syndrome with a modified phenotype. We employed single-nucleotide polymorphism array genotyping to identify small deletions in patients diagnosed with DBA and other anemias lacking molecular diagnoses...