JAK2, CALR, and MPL Mutation Profiles in Colombian patients with BCR-ABL Negative Myeloproliferative Neoplasms

Background: Among the chronic myeloproliferative neoplasms (MPNs) not associated with BCR-ABL mutations are polycythemia vera, primary myelofibrosis, and essential thrombocythemia. These diseases are caused by mutations in genes, such as the JAK2, MPL, and CALR genes, which participate in regulating the JAK-STAT signaling pathway. Objective: This study aimed to establish the frequencies of mutations in the JAK2, MPL, and CALR genes in a group of Colombian patients with a negative clinical diagnosis of BCR-ABL chronic myeloproliferative neoplasms. Methods: The JAK2 V617F and MPL W515K mutations and deletions or insertions in exon 9 of the CALR gene were analyzed in 52 Colombian patients with polycythemia vera, primary myelofibrosis, and essential thrombocythemia. Results: The JAK2V617F mutation was carried by 51.9% of the patients, the CALR mutation by 23%, and the MPL mutation by 3.8%; 23% were triple-negative for the mutations analyzed. In these neoplasms, 6 mutation types in CALR were identified, one of which has not been previously reported. Additionally, one patient presented a double mutation in both the CALR and JAK2 genes. Regarding the hematological results for the mutations, significant differences were found in the hemoglobin level, hematocrit level, and platelet count among the three neoplasms. Conclusion: Thus, this study demonstrates the importance of the molecular characterization of the JAK2, CALR and MPL mutations in Colombian patients (the genetic context of which remains unclear in the abovementioned neoplasms) to achieve an accurate diagnosis, a good prognosis, adequate management, and patient survival.

Antecedentes: Entre las neoplasias mieloproliferativas crónicas no asociadas con mutaciones BCR-ABL se encuentran la policitemia vera, la mielofibrosis primaria y la trombocitemia esencial. Estas enfermedades están causadas por mutaciones en genes, como los genes JAK2, MPL y CALR, que participan en la regulación de la vía de señalización JAK-STAT. Objetivo: Establecer las frecuencias de mutaciones en los genes JAK2, MPL y CALR en un grupo de pacientes colombianos con diagnóstico clínico negativo de NMP BCR-ABL. Metodos: Se analizaron las mutaciones y deleciones o inserciones JAK2 V617F y MPL W515K en el exón 9 del gen CALR en 52 pacientes colombianos con policitemia vera, mielofibrosis primaria y trombocitemia esencial. Resultados: La mutación JAK2V617F la portaban el 51.9% de los pacientes, la mutación CALR el 23.0% y la mutación MPL el 3.8%; El 23.0% fueron triple negativos para las mutaciones analizadas. En estas neoplasias se identificaron seis tipos de mutación en CALR, uno de los cuales no ha sido reportado previamente. Además, un paciente presentó una doble mutación tanto en el gen CALR como en el JAK2. En cuanto a los resultados hematológicos para las mutaciones, se encontraron diferencias significativas en el nivel de hemoglobina, el nivel de hematocrito y el recuento de plaquetas entre las tres neoplasias. Conclusiones: Así, este estudio demuestra la importancia de la caracterización molecular de las mutaciones JAK2, CALR y MPL en pacientes colombianos (cuyo contexto genético aún no está claro en las neoplasias antes mencionadas) para lograr un diagnóstico certero, un buen pronóstico, un manejo adecuado y una mejoría del paciente. supervivencia.

Biomarcadores en las neoplasias mieloproliferativas clásicas BCR-ABL1 negativas / Biomarkers in Classical Myeloproliferative Neoplasms BCR-ABL1 negative

Introducción: Los biomarcadores son útiles en la definición del diagnóstico, pronóstico y seguimiento de múltiples enfermedades. La detección o medición de uno o más biomarcadores específicos representan alteraciones en vías genéticas o epigenéticas que controlan la proliferación, diferenciación o muerte celular. Las neoplasias mieloproliferativas constituyen un grupo fenotípicamente diverso de hemopatías malignas de origen clonal, caracterizadas por una sobreproducción simple o multilineal de los elementos eritroides, mieloides y megacariocíticos; así como de una marcada predisposición a la trombosis, sangramiento y transformación leucémica. Dentro de ellas se incluyen: la policitemia vera, la trombocitemia esencial y la mielofibrosis primaria, conocidas como neoplasias mieloproliferativas clásicas BCR-ABL1 (o cromosoma Philadelfia) negativas. Las mutaciones somáticas en genes como JAK2, MPL y CARL se comportan como mutaciones drivers iniciadoras, responsables del fenotipo mieloproliferativo. Métodos: Se revisaron artículos relacionados publicados en los últimos años, en algunas bases de datos de la Biblioteca Virtual de Salud. En esta revisión se exponen los mecanismos moleculares generales de esas mutaciones y su expresión clínica; se hace referencia a las neoplasias mieloproliferativas triple negativas y sus implicaciones clínicas y se indica el algoritmo diagnóstico propuesto por la Organización Mundial de la Salud que incluye los nuevos biomarcadores. Conclusiones: El estudio molecular proporciona información valiosa para el diagnóstico y seguimiento de las neoplasias mieloprolifrativas, pero no logra diferenciar entre cada una de ellas. Por esto, se requiere de la adecuada aplicación del método clínico para llegar a un diagnóstico certero con ayuda de otros exámenes complementarios(AU)

Introduction: Biomarkers are useful in the definition of diagnosis, prognosis and monitoring of multiple diseases. The detection or measurement of one or more specific biomarkers represents alterations in genetic or epigenetic pathways that control proliferation, differentiation or cell death. The myeloproliferative neoplasms constitute a phenotypically diverse group of malignant hemopathies of clonal origin, characterized by a simple or multilinear overproduction of the erythroid, myeloid and megakaryocytic elements; as well as a marked predisposition to thrombosis, bleeding and leukemic transformation. These include: polycythemia vera, essential thrombocythemia, and primary myelofibrosis, known as classical negative myeloproliferative neoplasms BCR-ABL1 (or Philadelphia chromosome). Somatic mutations in genes such as JAK2, MPL and CARL behave as initiating driver mutations responsible for the myeloproliferative phenotype. Methods: Articles published in the last years were reviewed in some databases of the Virtual Health Library (VHL). In this review we expose the general molecular mechanisms of these mutations and their clinical expression; reference is made to the triple negative myeloproliferative neoplasms and their clinical implications and the diagnostic algorithm proposed by the World Health Organization that includes the new biomarkers is indicated. Conclusions: The molecular study provides valuable information for the diagnosis and monitoring of myeloproliferative neoplasms, but fails to differentiate between each of them. Therefore, the appropriate application of the clinical method is required to arrive at an accurate diagnosis with the help of other complementary tests(AU)

Can Histochemical c-mpl Positivity in Bone Marrow be a Predictor for Splenectomy in Immune Thrombocytopenia?

Purpose: Splenectomy is used as the second line therapy in patients with immune thrombocytopenia (ITP). However, there is no parameter predicting splenectomy decision. Thrombopoietin is the main regulator of platelet count through its receptor c-mpl. The aim of the present study was to evaluate immune histochemical Cloned Myeloid Leukemia Virus (c-mpl) positivity in bone marrow specimens of ITP patients with or without splenectomy indications. Methods: Pre-splenectomy bone marrow was stained for c-mpl, that was taken from 24 patients with ITP and who had splenectomy as well as bone marrow samples from 30 patients with ITP who did not have splenectomy. Results: c-mpl negativity was higher in splenectomized patients (n: 23) compared to patients without splenectomy (n:18). A significant difference was found for platelet counts before and after splenectomy. Our study show that, c-mpl positivity was statistically significant in patient group who did not have splenectomy. In the patient group who had the splenectomy, c-mpl was not associated with refractory status. Conclusion: The significant level of c-mpl negativity might be the useful parameter for splenectomy indication in patients with immune thrombocytopenia.

Molecular genetics of BCR-ABL1 negative myeloproliferative neoplasms in India

Introduction: Over the past decade, we have moved on from a predominantly morphological and clinical classification of myeloproliferative neoplasms (MPN) to a more evolved classification that accounts for the molecular heterogeneity that is unique to this subgroup of hematological malignancies. This usually incorporates mutations in Janus kinase 2 (JAK2), MPL, and calreticulin (CALR) genes. In this manuscript, we report the frequency of these mutations in a cohort of Indian patients at a tertiary cancer center. Materials and Methods: One hundred and thirty cases of MPN were included in this study. These cases were diagnosed and classified based on the World Health Organization 2008 criteria. JAK2 and MPL mutations were detected using high sensitivity allele-specific polymerase chain reaction using fluorescent labeled primers followed by capillary electrophoresis. A subset of JAK2 and CALR mutations were assessed using a fragment length assay. Results: Among the MPN, we had 20 cases of polycythemia vera (PV), 34 cases of essential thrombocythemia (ET), and 59 of myelofibrosis (MF). JAK2, MPL, and CALR mutations were mutually exclusive of each other. Seventeen cases were categorized as MPN unclassifiable (MPN-U). JAK2p.V617F and MPL mutations were present in 60% (78 of 130) and 5.3% (7 of 130) of all MPN. All the PV cases harbored the JAK2 p.V617F mutation. A total of 23.8% (31 of 130) of patients harbored CALR mutations. CALR exon 9 mutations were detected in 60.8% (14 of 23) and 50% (5 of 10) of JAK2 and MPL negative MF and ET cases, respectively. MPN-U cases included three JAK2 p.V617F positive, two MPL p.W515 L, and 12 CALR positive cases. Ten different types of CALR indels (8 deletions and 2 insertions) were detected of which Type I and Type II mutations were the most common, occurring at a frequency of 45.1% (14 of 31) and 22.5% (7 of 31), respectively. Discussion and Conclusion: We report frequencies of JAK2 p. V617F, MPL exon 10 and CALR mutations in 130 patients similar to those reported in western literature. These mutations carry not only diagnostic but also prognostic relevance.

Primary Myelofibrosis with MPL S505N Mutation: The First Case Reported in Korea

MPL mutation is an important molecular marker in myeloproliferative neoplasms (MPN). Although MPL W515 is a hot spot for missense mutations in MPN, MPL S505 mutations have been reported in both familial and non-familial MPN. A 72-year-old male visited the hospital, complaining mainly of dizziness and epistaxis. Leukocytosis, anemia, thrombocytopenia, tear drop cells, nucleated RBCs, and myeloblasts were observed in both complete blood cell counts and peripheral blood smears. Bone marrow aspiration failed due to dilution with peripheral blood. BM biopsy indicated hypercellular marrow, megakaryocytic proliferation with atypia, and grade 3 reticulin fibrosis. Conventional cytogenetics results were as follows: 46,XY,del(13)(q12q22)[19]/46,XY[1]. Molecular studies did not detect JAK2 V617F, BCR/ABL translocation, JAK2 exon 12, and CALR exon 9 mutations. The MPL S505N mutation was verified by colony PCR and Sanger sequencing following gene cloning. Based on the above findings, a diagnosis of overt primary myelofibrosis (PMF) was indicated. Mutation studies of buccal and T cells were not conducted. Further, family members were not subjected to mutation studies. Therefore, we were unable to determine whether this mutation was familial or non-familial. Six months after the first visit to the hospital, the patient died due to pneumonia and sepsis. Thrombotic symptoms or major bleeding events did not develop during the survival period following diagnosis of PMF. To the best of our knowledge, this may be the first reported case of PMF with the MPL S505N mutation in Korea.

Mutaciones en JAK2, MPL y CALR en neoplasias mieloproliferativas: análisis de disociación de alta resolución / Mutations in JAK2, MPL and CALR in myeloproliferative neoplasms: High Resolution Melting analysis / Mutações em JAK2, MPL e CALR em neoplasias mieloproliferativas: análise de dissociação em alta resolução

La policitemia vera (PV), la trombocitemia esencial (TE) y la mielofibrosis idiopática (MI) constituyen las Neoplasias Mieloproliferativas cromosoma Filadelfia negativas (NMP Ph-neg). La mutación V617F en el exón 14 del gen JAK2 ha sido descripta en un 90% de los casos de PV y en un 50% de TE y MI. Recientemente, se identificaron mutaciones en el exón 10 del gen MPL y en el exón 9 del gen CALR, presentes en un 5 y 73% de pacientes con TE y MI sin mutaciones en JAK2, respectivamente. En el presente trabajo se estudió la detección de dichas mutaciones en 52 pacientes con NMP, mediante amplificaciones por PCR en Tiempo Real con posterior análisis por High Resolution Melting (HRM) y secuenciación. La mutación V617F en JAK2 fue registrada en un 83,3% de pacientes con PV y 42,8% con TE y MI. Un 6,25% y 56,25% de pacientes con TE y MI JAK2 negativos resultaron positivos para mutaciones en el exón 10 de gen del receptor de la trombopoyetina (MPL) y el exón 9 de gen de la calreticulina (CALR). El análisis por HRM puede ser considerado como herramienta diagnóstica eficaz para las NMP debido a su alta sensibilidad, bajo costo y tiempo de procesado, teniendo en cuenta el impacto clínico que podría tener en los pacientes la detección temprana de dichas mutaciones.

Polycythemia vera (PV), essential thrombocythemia (TE) and idiopathic myelofibrosis (MI) are Philadelphia chromosome-negative myeloproliferative neoplasms (MPN-Ph. Neg). The presence of the V617F mutation in exon 14 of the JAK2 gene has been described in 90% of cases of PV and 50% of MI and TE. Recently, mutations in exon 10 of the MPL gene and exon 9 of CALR gene have been identified, which are present in 5 to 73% of patients with TE and MI without mutations in JAK2, respectively. In this work, the detection of these mutations was studied in 52 patients with NMP, using real time PCR amplifications with subsequent High Resolution Melting (HRM) analysis and sequencing. A total of 83.3% of patients with PV and 42.8% with MI and TE were recorded as positive for the V617F mutation in JAK2. A total of 6.25% and 56.25% of the patients with MI and TE with non-mutated JAK2 were positive for mutations in MPL exon 10 and CALR exon 9. HRM analysis could be considered an effective diagnostic tool for NMP due to its high sensitivity, low cost and processing time, taking into account the clinical impact that early detection of such mutations could have on patients.

Policitemia vera (PV), trombocitemia essencial (TE) e mielofibrose idiopática (MI) constituem as Neoplasias Mieloproliferativas cromossomo Filadélfia negativas (NMP Ph-neg). A mutação V617F no exon 14 do gene JAK2 foi descrita em 90% dos casos de PV e em 50% de TE e MI. Recentemente, foram identificadas mutações no exon 10 do gene MPL e no exon 9 do gene CALR, presentes em 5 a 73% de pacientes com TE e MI sem mutações em JAK2, respectivamente. Neste trabalho foi estudada a detecção de tais mutações em 52 pacientes com NMP, usando amplificações por PCR em Tempo Real, com posterior análise por High Resolution Melting (HRM) e sequenciamento. 83,3% dos pacientes com PV e 42,8% com TE e MI foram positivos para a mutação V617F em JAK2. 6,25% e 56,25% de pacientes com TE e MI JAK2 negativo foram positivos para mutações no exon 10 de gene do receptor da trombopoietina (MPL) e o exon 9 de gene da calreticulina (CALR). A análise por HRM pode ser considerada como ferramenta de diagnóstico eficaz para as NMP, devido à sua alta sensibilidade, baixo custo e tempo de processamento, tendo em conta o impacto clínico que poderia ter a detecção precoce de tais mutações nos pacientes.

Immunogenicity and efficacy of recombinant 78 kDa antigen of Leishmania donovani formulated in various adjuvants against murine visceral leishmaniasis

Objective: To analyze the protective efficacy of recombinant 78 kDa antigen of Leishmania donovani in combination with two adjuvants, that is, cationic liposomes or MPL-A against visceral leishmaniasis in BALB/c mice. Methods: The genomic DNA of promastigotes was isolated and 583 bp of T cell epitopes of gene encoding 78 kDa was amplified using specific primers. The amplified gene was cloned into pET28c, transformed into Escherichia coli BL21 (DE3) and got expressed after IPTG induction. The recombinant protein was then purified using Ni-NTA and named r78. Three groups of mice were immunized with 10 μg of r78 plus MPL-A, r78 encapsulated in positively charged liposomes and control animals immunized with PBS. Two booster doses were given with the respective vaccine at an interval of 2 weeks each. Mice were challenged with 1 × 107 Leishmania promastigotes and sacrificed on different post infection/challenge days. Results: Immunization with r78 along with MPL-A and liposome-encapsulated r78 brought a significant reduction in parasite load. In comparison to the infected controls, the parasite load declined by 96.2% in mice immunized with r78 plus MPL-A and 97.23% in animals immunized with liposome-encapsulated r78. The immunized animals also exhibited profound DTH response. The serum antibody responses increased from 15 to 90 days post infection/challenge. Immunized animals showed greater IgG2a levels and lesser IgG1 levels in comparison to the infected controls. The splenocytes from immunized mice were cultured, stimulated with r78 and analyzed for cytokine profile. The levels of IL-2 and IFN-γ were greater in immunized animals as compared to control mice. Conclusions: The study proves that r78 in combination with suitable adjuvants is a potential vaccine candidate and may be instrumental in control of visceral leishmaniasis.

Immunogenicity and efficacy of recombinant 78 kDa antigen of Leishmania donovani formulated in various adjuvants against murine visceral leishmaniasis

OBJECTIVE@#To analyze the protective efficacy of recombinant 78 kDa antigen of Leishmania donovani in combination with two adjuvants, that is, cationic liposomes or MPL-A against visceral leishmaniasis in BALB/c mice.@*METHODS@#The genomic DNA of promastigotes was isolated and 583 bp of T cell epitopes of gene encoding 78 kDa was amplified using specific primers. The amplified gene was cloned into pET28c, transformed into Escherichia coli BL21 (DE3) and got expressed after IPTG induction. The recombinant protein was then purified using Ni-NTA and named r78. Three groups of mice were immunized with 10 μg of r78 plus MPL-A, r78 encapsulated in positively charged liposomes and control animals immunized with PBS. Two booster doses were given with the respective vaccine at an interval of 2 weeks each. Mice were challenged with 1 × 10(7)Leishmania promastigotes and sacrificed on different post infection/challenge days.@*RESULTS@#Immunization with r78 along with MPL-A and liposome-encapsulated r78 brought a significant reduction in parasite load. In comparison to the infected controls, the parasite load declined by 96.2% in mice immunized with r78 plus MPL-A and 97.23% in animals immunized with liposome-encapsulated r78. The immunized animals also exhibited profound DTH response. The serum antibody responses increased from 15 to 90 days post infection/challenge. Immunized animals showed greater IgG2a levels and lesser IgG1 levels in comparison to the infected controls. The splenocytes from immunized mice were cultured, stimulated with r78 and analyzed for cytokine profile. The levels of IL-2 and IFN-γ were greater in immunized animals as compared to control mice.@*CONCLUSIONS@#The study proves that r78 in combination with suitable adjuvants is a potential vaccine candidate and may be instrumental in control of visceral leishmaniasis.

Frequency and Clinicohematologic Characteristics of MPL W515 Mutations in Patients with Myeloproliferative Neoplasms

BACKGROUND: Recently, myeloproliferative leukemia (MPL) W515 mutations have been reported to be molecular markers for myeloproliferative neoplasms (MPNs). We studied the association between MPL W515 mutations and the clinico-hematological features of patients with MPNs. METHODS: Our study included 154 consecutive patients diagnosed with MPNs (31 had polycythemia vera [PV]; 106, essential thrombocythemia [ET]; and 17, primary myelofibrosis [PMF]). MPL W515 mutations were detected by real-time PCR and direct sequencing methods. RESULTS: The MPL W515L mutation was found in 4 patients and the MPL W515A mutation was detected in 1 patient. These 5 patients were diagnosed with JAK2 V617F-negative ET, and they accounted for 12.5% of patients with JAK2 V617F-negative ET. The patients with MPL W515-positive ET showed significantly lower hemoglobin levels and WBC counts than did patients with MPL W515-negative ET or JAK2 V617F-positive ET. CONCLUSIONS: MPL W515 mutation is a useful diagnostic marker for JAK2 V617F-negative MPNs and it is associated with specific hematologic characteristics such as lower hemoglobin levels and WBC counts.

Calreticulin Exon 9 Mutations in Myeloproliferative Neoplasms

BACKGROUND: Calreticulin (CALR) mutations were recently discovered in patients with myeloproliferative neoplasms (MPNs). We studied the frequency and type of CALR mutations and their hematological characteristics. METHODS: A total of 168 MPN patients (36 polycythemia vera [PV], 114 essential thrombocythemia [ET], and 18 primary myelofibrosis [PMF] cases) were included in the study. CALR mutation was analyzed by the direct sequencing method. RESULTS: CALR mutations were detected in 21.9% of ET and 16.7% of PMF patients, which accounted for 58.5% and 33.3% of ET and PMF patients without Janus kinase 2 (JAK2) or myeloproliferative leukemia virus oncogenes (MPL) mutations, respectively. A total of five types of mutation were detected, among which, L367fs*46 (53.6%) and K385fs*47 (35.7%) were found to be the most common. ET patients with CALR mutation had lower leukocyte counts and ages compared with JAK2-mutated ET patients. CONCLUSION: Genotyping for CALR could be a useful diagnostic tool for JAK2-or MPL-negative ET or PMF patients. CALR mutation may be a distinct disease group, with different hematological characteristics than that of JAK2-positive patients.

JAK2 V617F, MPL, and CALR Mutations in Korean Patients with Essential Thrombocythemia and Primary Myelofibrosis

Mutations in the calreticulin gene, CALR, have recently been discovered in subsets of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). We investigated Korean patients with ET and PMF to determine the prevalence, and clinical and laboratory correlations of CALR/JAK2/MPL mutations. Among 84 ET patients, CALR mutations were detected in 23 (27.4%) and were associated with higher platelet counts (P=0.006) and lower leukocyte counts (P=0.035) than the JAK2 V617F mutation. Among 50 PMF patients, CALR mutations were detected in 11 (22.0%) and were also associated with higher platelet counts (P=0.035) and trended to a lower rate of cytogenetic abnormalities (P=0.059) than the JAK2 V617F mutation. By multivariate analysis, triple-negative status was associated with shorter overall survival (HR, 7.0; 95% CI, 1.6-31.1, P=0.01) and leukemia-free survival (HR, 6.3; 95% CI, 1.8-22.0, P=0.004) in patients with PMF. The type 1 mutation was the most common (61.1%) type among all patients with CALR mutations, and tended toward statistical predominance in PMF patients. All 3 mutations were mutually exclusive and were never detected in patients with other myeloid neoplasms showing thrombocytosis. CALR mutations characterize a distinct group of Korean ET and PMF patients. Triple-negative PMF patients in particular have an unfavorable prognosis, which supports the idea that triple-negative PMF is a molecularly high-risk disease.

Correlation of Genomic Characteristic with Disease Progression in Polycythemia Vera / 天津医药

Objective To screen mutations in genes including ASXL1, TET2, IDH1, IDH2, SETBP1, MPL515, JAK2 exon 12 and JAK2V617 in 135 polycythemia vera (PV) patients. To assess progreasson and genomics characteristics post polycythemic myelofibrosis. Methods DNA sequencing of ASXL1(Exon12),TET2 (Exons 3-11),IDH1(Exon4),IDH2(Ex-on4),SEPBP1(Exon4),JAK2 exon 12 and MPL515 (Exon 10) genes were carried out using Sanger method. JAK2V617 muta-tion was detected by allele-specific PCR in patients with PV. In the mean time, the mutation load of JAK2V617F allele (V617F%) was evaluated by real-time PCR using Tagman MGB probe. Then, the significant of gene mutations and clinical outcomes of post-PV Myelofibrosis(PPMF)was analyzed. To study risk factors of PPMF, logistic regression were employed. Results ASXL1, TET2, IDH1, IDH2 were mutated in 7.69%(8/104), 5.26%(1/19) , 0.08%(1/120) and 0.08%(1/121) of all PV patient respectively. JAK2 was mutated in 82.22%(111/135) of PV patients with mutation rate of exon12 of 2.96%(4/135) and there were no mutation of MPL515 and SETBP1 in PV patients. ASXL1 mutation was found in 31.82%(7/22) PPMF patients. Spearman analysis showed that ASXL1 is correlated with JAK2V617F (V617F%) (rs=0.298,P=0.002). The hemo-globin was lower in patients with ASXL1 mutation than patient without mutation (wild type). Leukocyte count, V617F%>50%rate, thrombosis and PPMF were higher in patients with ASXL1 mutation than that of ASXL1 wild type(P＜0.05). ASXL1 mu-tation, V617F%>50% rate and splenomegaly were all risk factors of PPMF. Conclusion ASXL1 mutation is the risk-fac-tor of PPMF and may promote V617F%by some mechanism.

Effect of simulated microgravity on proliferation and differentiation of the human megakaryocyte cell / 实用医学杂志

Objective To investigate the effect of simulated microgravity on the proliferation and differentiation of the human megakaryocyte cells in vitro. Methods The fourth generation rotating cell culture system (RCCS-4) was used to generate the simulated microgravity environment. The cell viability was assessed by trypan blue staining method. The proliferation of cells was assessed by cell counting method and CCK8 method. The CD41+/CD61+ cells rate and the cells cycle were detected by flow cytometry. The expression levels of thrombopoietin receptor (c-mpl) and transcription factors were detected with RT-PCR. Results After 24, 48, 72 h, culture under simulated microgravity resulted in a significant decrease in the cell number , proliferative activity, cells in the G2/M phase and levels of c-mpl mRNA expression in comparison with that under the normal gravity (P < 0.05). After 48 h and 72 h culture, CD41+/CD61+ cells ratio decreased and RUNX-1 mRNA expression was down-regulated in cells of the group SMG compared with that of the group NG (P < 0.05). Conclusion Microgravity can inhibit the proliferation and differentiation of human megakaryocyte cells in vitro. The mechanism may be that TPO/c-mpl pathway was inhibited by down regulating the expression of c-mpl which transcriptional inhibition lead to.

Detection of MPL exon 10 mutations in myeloproliferative neoplasms V617F-negative patients / 白血病·淋巴瘤

Objective To explore the frequencies of MPL exon 10 mutations in JAK2 V617F-negative myeloproliferative neoplasms patients. Methods MPLW515K/L was processed through allele-specific PGR combined with direct sequence analysis. The mutations of others MPL exon 10 were detected by single strand conformation polymorphism PGR (PCR-SSCP) combined with direct sequencing. Results Of the 103 patients with JAK2 V617F-negtive myeloproliferative neoplasms patients, 1 carried MPLW515K mutation (TGG→AAG)in PMF; 1 was found to have new mutation (CTGGTGATCGCT insert) in ET and have homozygous mutation. Conclusion JAK2 V617F-negtive myeloproliferative neoplasms patients carried additional mutations in addition to W515K/L mutations in MPL exon 10, but its frequency of mutation is low.

JAK2 V617F and MPL W515L/K Mutations in Korean Patients with Essential Thrombocythemia / 대한진단검사의학회지

JAK2 V617F and MPL W515L/K mutations have been reported in approximately 50% and 5% of the patients with essential thrombocythemia (ET), respectively. We investigated the frequency of MPL W515L/K mutations in a series of consecutive patients with ET and post-essential thrombocythemia myelofibrosis (post-ET MF). The study subjects were 63 patients diagnosed either with ET (N=59) or post-ET MF (N=4) at our institution between June 2006 and February 2010. Among them, 35 (55.6%) had the JAK2 V617F mutation. MPL W515L/K mutations were detected by direct sequencing analyses of exon 10, and 2 patients were found to harbor the following MPL mutations: W515L in 1 patient with ET and W515K in 1 patient with post-ET MF. Neither of the patients had the JAK2 V617F mutation. The frequencies of the MPL W515L/K and JAK2 V617F-negative mutations in our subjects with ET/post-ET MF were 3.2% (2/63) and 7.1% (2/28), respectively. This is the first study to report the frequency of JAK2 V617F and MPL W515L/K mutations in Korean patients with ET/post-ET MF.

Upregulation of proto-oncogene c-mpl by interleukin-13 in Dami cells / 中国病理生理杂志

AIM: To investigate the effects of recombinant human interleukin-13 (rhIL-13) on the expression of proto-oncogene c-mpl in Dami cells, a human megakaryobiastic leukemia cell line. METHODS: The expression of c-mpl mRNA in Dami cells was investigated with RT-PCR. The expression of membrane-bound protein c-mpl on Dami cells was investigated with ligand combination experiment. RESULTS: In RT-PCR experiment, we found the quantitis of expression of c-mpl mRNA in 25 ?g/L rhIL-13 group increased by 24.8%. In ligand combination experiment, we found quantitis of expression of membrane-bound protein c-mpl in 100 ?g/L rhIL-13 group increased by 28.5% ( P

Clinical experience of extracorporeal shock wave lithotripsy(Dornier lithotriptor MPL 9000) for urinary calculi / 대한비뇨기과학회지

MPL 9000 lithotriptor may be characterized by ultrasonic localization, automatic target system, water cushion and under water spark gap generation of shock wave. In an effort to evaluate clinical efficiency of this machine, we analyzed therapeutic results of 250 cases of urinary calculi treated by extracorporeal shock wave lithotripsy (ESWL) using MPL 9000 lithotriptor. Technically it was difficult to visualize the upper ureter stones with ultrasonic scanning, so all of them were pushed up before treatment. For staghorn stones or large stones, percutaneous nephrolithotomy (PCNL) or ureteral stenting were performed before treatment selectively. The overall stone free rate. at 4 weeks after last session, was 89.2% while that of stones larger than 3cm was 50%. The complications such as gross hematuria, flank pain, steinstrasse and fever were controlled successfully by conservative treatment. In conclusion, ESWL with MPL 9000 might be successful in most patients with urolithiasis but in cases of large renal stone or upper ureteral stone auxiliary procedures will be required.

Initial Clinical Trials of Urinary Stones with Dornier Lithotriptor MPL 9000 / 대한비뇨기과학회지

Extracorporeal shock wave lithotripsy was performed in 231 patients for 13 months with Dornier MPL 9000 lithotriptor. The 231 patients had renal ( 48.9%) or ureteral (51.1%) stones varying from 0.6 to 4.4cm (mean 1.2cm) in size. Among 231 patients, 184 patients (79.7%) completed the treatment with 1 session and the number of treatment sessions increased in larger stones and in situ impacted ureteral stones, with an average of 1.3 sessions. The success rate (rate free of calculi plus that of clinically insignificant residual fragments) was 98.3 %. No general or regional anesthesia was required but parental analgesics were required in 22.9% of the treatment sessions. There were no significant complications in any patient. Therefore, extracorporeal shock wave lithotripsy with Dornier MPL 9000 lithotriptor is considered to be a safe and efficient procedure for initial treatment of urinary stones.