Diamond-Blackfan anemia (DBA) is predominantly underlined by mutations in genes encoding ribosomal proteins (RP); however, its etiology remains unexplained in approximately 25 % of patients. We previously reported a novel heterozygous RPS7 mutation hg38 chr2:g.3,580,153G > T p.V134F in one female patient and two asymptomatic family members, in whom mild anemia and increased erythrocyte adenosine deaminase (eADA) activity were detected. We observed that altered erythrocyte metabolism and oxidative stress which may negatively affect the lifespan of erythrocytes distinguishes the patient from her asymptomatic family members. Pathogenicity of the RPS7 p.V134F mutation was extensively validated including molecular defects in protein translational activity and ribosomal stress activation in the cellular model of this variant.
Diamond-Blackfan anemia (DBA) is a rare congenital erythroid aplasia, underlied by haploinsufficient mutations in genes coding for ribosomal proteins (RP) in approximately 70% of cases. DBA is frequently associated with somatic malformations, endocrine dysfunction and with an increased predisposition to cancer. Here we present clinical and genetic characteristics of 62 patients from 52 families enrolled in the Czech and Slovak DBA Registry. Whole exome sequencing (WES) and array comparative genomic hybridization (aCGH) were employed to identify causative mutations in newly diagnosed patients and in cases with previously unrecognized molecular pathology. RP mutation detection rate was 81% (50/62 patients). This included 8 novel point mutations and 4 large deletions encompassing some of the RP genes. Malignant or predisposing condition developed in 8/62 patients (13%): myelodysplastic syndrome in 3 patients; breast cancer in 2 patients; colorectal cancer plus ocular tumor, diffuse large B-cell lymphoma and multiple myeloma each in one case. These patients exclusively harbored RPL5, RPL11 or RPS19 mutations. Array CGH is beneficial for detection of novel mutations in DBA due to its capacity to detect larger chromosomal aberrations. Despite the importance of genotype-phenotype correlation in DBA, phenotypic differences among family members harboring an identical mutation were observed.
- MeSH
- Diamondova-Blackfanova anemie komplikace epidemiologie genetika MeSH
- genetické asociační studie MeSH
- lidé MeSH
- mutace * MeSH
- nádory etiologie MeSH
- registrace MeSH
- ribozomální proteiny genetika MeSH
- rodina MeSH
- sekvenování exomu MeSH
- srovnávací genomová hybridizace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- Slovenská republika MeSH
Glucose-6-phosphate isomerase (GPI) deficiency, a genetic disorder responsible for chronic nonspherocytic hemolytic anemia, is the second most common red blood cell glycolytic enzymopathy. We report three patients from two unrelated families of Czech and Slovak origin with macrocytic hemolytic anemia due to GPI deficiency. The first patient had 15% of residual GPI activity resulting from two new heterozygous missense mutations c.478T>C and c.1414C>T leading to substitutions p.(Ser160Pro) and p.(Arg472Cys). Two other patients (siblings) inherited the same c.1414C>T p.(Arg472Cys) mutation in a homozygous constitution and lost approximately 89% of their GPI activity. Erythroid hyperplasia with dysplastic features was observed in the bone marrow of all three patients. Low hepcidin/ferritin ratio and elevated soluble transferrin receptor detected in our GPI-deficient patients suggest disturbed balance between erythropoiesis and iron metabolism contributing to iron overload.
- MeSH
- alely MeSH
- biologické markery MeSH
- biopsie MeSH
- dítě MeSH
- erytrocytární znaky MeSH
- erytroidní buňky metabolismus MeSH
- erytropoéza genetika MeSH
- genotyp MeSH
- glukosa-6-fosfátisomerasa chemie genetika MeSH
- hemolytická nesférocytická kongenitální anemie krev diagnóza genetika MeSH
- hepcidiny krev MeSH
- konformace proteinů MeSH
- kostní dřeň patologie MeSH
- lidé MeSH
- molekulární modely MeSH
- mutace * MeSH
- regulace genové exprese MeSH
- sekvenční analýza DNA MeSH
- substituce aminokyselin * MeSH
- vztahy mezi strukturou a aktivitou MeSH
- železo metabolismus MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Erythroferrone (ERFE) and TMPRSS6 are important proteins in the regulation of iron metabolism. The objective of the study was to examine splenic ERFE and liver TMPRSS6 synthesis in rats treated with a combination of iron and erythropoietin (EPO). EPO was administered to female Wistar rats at 600U/day for four days, iron-pretreated rats received 150mg of iron before EPO treatment. Content of ERFE and TMPRSS6 proteins was determined by commercial antibodies. Iron pretreatment prevented the EPO-induced decrease in hepcidin expression. Content of phosphorylated SMAD 1,5,8 proteins was decreased in the liver by both EPO and iron plus EPO treatment. Fam132b expression in the spleen was increased both by EPO and iron plus EPO treatments; these treatments also significantly induced splenic Fam132a expression. ERFE protein content in the spleen was increased both by EPO and iron plus EPO to a similar extent. EPO administration increased TMPRSS6 content in the plasma membrane-enriched fraction of liver homogenate; in iron-pretreated rats, this increase was abolished. The results confirm that iron pretreatment prevents the EPO-induced decrease in liver Hamp expression. This effect probably occurs despite high circulating ERFE levels, since EPO-induced ERFE protein synthesis is not influenced by iron pretreatment.
- MeSH
- erythropoetin farmakologie MeSH
- játra metabolismus MeSH
- krysa rodu rattus MeSH
- peptidové hormony metabolismus MeSH
- potkani Wistar MeSH
- serinové endopeptidasy metabolismus MeSH
- slezina metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- Asijci MeSH
- běloši MeSH
- buněčná diferenciace MeSH
- buňky kostní dřeně imunologie patologie MeSH
- chronická lymfatická leukemie etnologie imunologie patologie MeSH
- imunofenotypizace MeSH
- lidé MeSH
- počet lymfocytů MeSH
- prekurzorové B-lymfoidní buňky imunologie patologie MeSH
- studie případů a kontrol MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- dopisy MeSH
- práce podpořená grantem MeSH
Hexokinase (HK) is a key enzyme of glycolysis, the only metabolic pathway able to provide the red blood cell with ATP. HK deficiency is a very rare hereditary disorder with severe chronic nonspherocytic hemolytic anemia (HNSHA) as a major clinical feature. To date, only 24 patients with HK deficiency have been identified. Here, we report the molecular analysis of six new cases of HK deficiency. A total of six different mutations were detected in HK1, four of them described here for the first time: c.2599C>T p.(His867Tyr), c.1799C>T p.(Thr600Met), c.873-2A>G and c.493-1G>A. The pathogenic nature of the identified missense mutations was confirmed by biochemical and 3-dimensional structural analysis. The effects of the novel splice site mutation c.873-2A>G were studied at the level of pre-mRNA processing, and confirmed at the protein level. All together, these results provide a better insight into the pathogenesis of this rare red cell disorder, and contribute to a better understanding of the genotype-phenotype correlation in HK deficiency.
- MeSH
- dítě MeSH
- erytrocyty enzymologie MeSH
- genetické asociační studie MeSH
- hexokinasa nedostatek genetika MeSH
- kojenec MeSH
- lidé MeSH
- missense mutace MeSH
- místa sestřihu RNA genetika MeSH
- mladý dospělý MeSH
- mutace MeSH
- předškolní dítě MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Tyrosine kinase inhibitors (TKIs) targeting BCR-ABL have dramatically improved chronic myeloid leukemia therapy. While imatinib remains to be the first line therapy, about 30% of patients develop resistance or intolerance to this drug and are recommended to switch to other TKIs. Nilotinib and dasatinib are currently implemented into the first line therapy and other inhibitors have already entered the clinical practice. This opens further questions on how to select the best TKI for each patient not only during the therapy but also at diagnosis. The individualized therapy concept requires a reliable establishment of prognosis and prediction of response to the available TKIs. We tested the ex vivo sensitivity of patient primary leukocytes to imatinib, nilotinib and dasatinib - two concentrations of each inhibitor for 48h incubation - and we evaluated the usefulness of such tests for the clinical practice. Besides reflecting the actual sensitivity to the therapy, our optimized simple tests were able to predict the outcome in 90/87% of patients, for the next 12/24months, respectively. According to these results, the presented ex vivo testing could help clinicians to select the appropriate drug for each patient at diagnosis and also at any time of the therapy.
- MeSH
- antitumorózní látky farmakologie terapeutické užití MeSH
- buněčná smrt účinky léků MeSH
- chemorezistence * MeSH
- chronická myeloidní leukemie farmakoterapie patologie MeSH
- dasatinib farmakologie terapeutické užití MeSH
- imatinib mesylát farmakologie terapeutické užití MeSH
- inhibitory proteinkinas farmakologie terapeutické užití MeSH
- leukocyty účinky léků patologie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- pyrimidiny farmakologie terapeutické užití MeSH
- viabilita buněk účinky léků MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The HUMARA assay, the most common method for evaluation of X-inactivation skewing in blood cells, has been reported to be usable in only about 80% of females, emphasizing the need for alternative methods for testing of HUMARA-uninformative individuals. We conducted an in silico search for potentially polymorphic tri-to-hexanucleotide repeats in the proximity of CpG islands located in 5' regions of X-chromosome genes to design five candidate assays (numbered I, II, III, IV, and V) combining methylation-specific restriction digest with PCR amplification in a manner similar to the HUMARA assay. The results obtained by these assays in 100 healthy females were compared to X-inactivation skewing measured by the AR-MSP method which is based on methylation-specific PCR amplification of the first exon of the AR gene. On the basis of statistical evidence, three of the novel assays (II, IV, and V), which were informative in 18%, 61%, and 55% of females in the cohort, respectively, may be used as alternatives or conjointly with the HUMARA assay to improve its reliability. The three new assays were combined with the HUMARA assay into a novel X-inactivation test leading to the increase of informative females in the cohort from 67% to 96%.
- MeSH
- androgenní receptory genetika MeSH
- biotest * MeSH
- CpG ostrůvky MeSH
- dítě MeSH
- DNA primery chemická syntéza MeSH
- dospělí MeSH
- exony MeSH
- inaktivace chromozomu X * MeSH
- lidé středního věku MeSH
- lidé MeSH
- lidské chromozomy X chemie MeSH
- metylace DNA MeSH
- mikrosatelitní repetice MeSH
- mladiství MeSH
- modely genetické MeSH
- počítačová simulace MeSH
- polymerázová řetězová reakce metody MeSH
- polymorfismus genetický MeSH
- senioři MeSH
- senzitivita a specificita MeSH
- studie případů a kontrol MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Heat shock proteins (Hsp) are important for the stability and function of cell proteins and thus for cell survival under physiological as well as stress conditions. Hsps were also reported to play an important role in tumorogenesis including leukemias. In this study we followed up Hsp70 and 90 protein levels in samples from patients with chronic myeloid leukemia (CML) to evaluate these Hsps with regard to their ability to characterize the disease status and disease prognosis. We analyzed 68 samples of total leukocytes of CML patients with different response to therapy with tyrosine kinase inhibitors. The results of Western blot analyses showed that the level of Hsp70 did not change in the course of the disease and did not correlate with response to therapy. In contrast, Hsp90 levels showed good correlation with the disease state. Patients with good response to therapy (major molecular response-MMR, molecular remission-CMR) had low expression levels of Hsp90, similar to those in healthy individuals. High Hsp90 levels were found in patients with resistance to therapy (hematological relapse-HR, accelerated phase or blast crisis), and in leukemic cell line K562. The results of the study suggested that not the kinetics but the particular level of Hsp90 at any time point since therapy start is of prognostic value: Hsp90 level above 0.27 significantly predicted poor response to TKI therapy (relapse, progression) and the level below 0.085 good response (MMR, CMR). In conclusion, Hsp90 level in total leukocytes could serve as a risk factor at diagnosis as well as during therapy and might help in clinical decision making especially in cases where BCR-ABL monitoring is of low predictive value. Our data suggest that high expression of HSP90 contributes to the aggressivity of the disease and should be considered as an important target for specialized CML therapy.
- MeSH
- bcr-abl fúzové proteiny genetika MeSH
- buňky K562 MeSH
- chronická myeloidní leukemie farmakoterapie genetika metabolismus MeSH
- dospělí MeSH
- genetická transkripce MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- nádorové biomarkery * MeSH
- nádorové buněčné linie MeSH
- prognóza MeSH
- progrese nemoci MeSH
- proteiny tepelného šoku HSP90 metabolismus MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
