OBJECTIVETo identify the MPL L391-V392ins12 spliceosome and analyze its frequencies in patients with myeloproliferative neoplasms (MPN).

METHODSMPL aberrant spliceosome was identified through reverse transcription polymerase chain reaction (RT-PCR)combined with cloning sequencing. The mutation of this spliceosome in 248 MPN patients and 200 normal people was determined by allele-specific polymerase chain reaction (AS-PCR).

RESULTSA novel aberrant spliceosome of MPL gene (MPL L391-V392ins12)was identified, i.e. 36 bp intron was retained between exon7 and exon8, and there were 12 amino acids (EGLKLLPADIPV)inserted. MPL L391-V392ins12 mutation was detected in 19 (7.66%)of the 248 patients with MPN, including 1 (1.92%) of 52 patients with PV, 14 (9.66%) of 145 with ET, and 4 (7.84%) of 51 with PMF. And the mutation was not detected in the group of 200 normal people.

CONCLUSIONMPL L391-V392ins12 spliceosome is an aberrant spliceosome present in the MPN. It can be detected in PV, ET and PMF, and more frequently in ET and PMF. This mutation may play an important role in the process of MPN.

Humans ; Mutation ; Myeloproliferative Disorders ; genetics ; Neoplasms ; genetics ; Polymerase Chain Reaction ; Receptors, Thrombopoietin ; genetics ; Spliceosomes

In 2008, WHO made the JAK2V617F gene mutation as one of the specific molecular diagnostic markers of BCR/ABL-negative myeloproliferative neoplasms (MPN). In 2013 two research teams demonstrated that whole genome sequencing technology (WGS) was used to detect calreticulin gene mutation in essential thrombocythaemia (ET) and primary myelofibrosis (PMF) patients with JAK2V617F⁻ and MPL⁻ mutations. In this review, the relationship of CALR gene mutation with MPN is briefly summarized.
Bone Marrow Neoplasms ; genetics ; Calreticulin ; genetics ; Humans ; Janus Kinase 2 ; genetics ; Mutation ; Myeloproliferative Disorders ; genetics ; Receptors, Thrombopoietin ; genetics

OBJECTIVE: To explore the potential pathogenetic mutations of primary hypereosinophilia（HEN）by sequencing FGFR1 FLT3, MPL and JAK2 genes, and to clarify their effect on clinical manifestation and prognosis of HEN patients. METHODS: The direct DNA sequencing was employed to detect the gene mutations of FGFR1, FLT3, MPL and JAK2 in HEN patients. RESULTS: One deletion mutation (2654_2753del) within tyrosine kinase domain of FLT3 gene was found in a patient suffered from severe symptoms and ended with dismal outcome, which induced a premature stop codon (G885fsX888). For FGFR1, a new variation described as 1014_1019del AACAGT for nucleotide change was found in 19 cases, resulting in T339_V340del at the protein level. CONCLUSION The deletion of 6 bases in the FGFR1 gene (1014_1019del AACAGT) is first reported as non-synonymous SNP (nsSNP) site in the patients with primary hypereosinophilia. Deletion mutations in the FLT3 gene may be related with malignant clinical features and poor prognosis.
Base Sequence ; Humans ; Hypereosinophilic Syndrome ; genetics ; Mutation ; Receptors, Thrombopoietin ; Sequence Deletion ; fms-Like Tyrosine Kinase 3

OBJECTIVE: To investigate the clinical characteristics, laboratorial and bone marrow pathological features of primary thrombocytopenia (ET) patients with different mutations of CALR, JAK2 and MPL genes. METHODS: The chinical data of 120 cases of ET in Jiangsu provincial people's hospital/ The First Affiliated Hospital of Nanjing Medical University from January 2015 to December 2017 were collected and analyzed, including 76 cases with JAK2 gene mutation, 40 cases with CALR gene mutation, 2 cases with MPL gene mutations, 2 cases without gene mutation. RESULTS: Among the ET patients, compared with the JAK2 gene mutation, CALR gene mutation showed statistically significant deareament of white blood cells and hemoglobin (P=0.001, P=0.01) and the male platelets in CALR group showed significant increament (P=0.04). Fourthermore, the average number of megakaryocytes and its cluster numbers in each hight power field of vision showed statistically significant decreament in CALR group as compared with JAK2 group (P=0.001, P=0.001), and thrombotic events in CALR group were signicantly lower than those in JAK2 group (7.5% vs 18.4%) (P=0.03). CONCLUSION Mutations of CALR, JAK2 have different clinical characteristics and blood pathological changes of Chinese ET patients, and their clinical significance is worth to explore.
Bone Marrow ; Calreticulin ; genetics ; China ; Humans ; Janus Kinase 2 ; genetics ; Male ; Mutation ; Receptors, Thrombopoietin ; genetics ; Thrombocythemia, Essential

Idiopathic myelofibrosis is a type of chronic myeloproliferative disorders characterized by splenomegaly, a leukoerythroblastic blood picture, teardrop poikilocytosis, in various degrees of bone marrow fibrosis and extramedullary hematopoiesis. In this paper, the biological characters and pathogenesis of idiopathic myelofibrosis such as mutation of tyrosine kinase receptor, mutation of GABA transporter 1, JAK2 mutation and c-MPl mutation, as well as other pathogenesis related with idiopathic myelofibrosis were reviewed.
GABA Plasma Membrane Transport Proteins ; genetics ; Humans ; Janus Kinase 2 ; genetics ; Mutation ; Primary Myelofibrosis ; etiology ; genetics ; Receptor Protein-Tyrosine Kinases ; genetics ; Receptors, Thrombopoietin ; genetics

The objective of this study was to investigate the expressions of TPO receptor (c-mpl) proteins on CD34 positive bone marrow cells (CD34+ BMCs), platelets and the expression of c-mpl mRNA in bone marrow cells of the patients with polycythemia vera (PV). The expressions of c-mpl proteins on CD34+ bone marrow hematopoietic cells of 13 PV patients and 15 normal controls were assessed by bicolor flow cytometry and the expressions of c-mpl proteins on platelets of 15 PV patients and 15 normal controls were assessed by monocolor flow cytometry, and the expressions of c-mpl mRNA in bone marrow hematopoietic cells (BMHCs) were assessed by RT-PCR. The results showed that no difference was found between the expression of c-mpl proteins on CD34+ BMHCs of PV patients (0.99% +/- 0.14%) and that of normal controls (0.92% +/- 0.12%) (p > 0.05). There was no difference too between the expression of c-mpl protein on platelets in PV patients (20.33% +/- 4.84%) and that in normal controls (23.50% +/- 3.64%) (p > 0.05). No difference between the expression of c-mpl mRNA in BMHCs of PV patients and that in normal controls was seen. In conclusion, the expressions of c-mpl proteins on CD34+ BMHCs, platelets and c-mpl mRNA in BMHCs of PV patients were not obviously abnormal.
Antigens, CD34 ; analysis ; Blood Platelets ; metabolism ; Bone Marrow Cells ; metabolism ; pathology ; Hematopoietic Stem Cells ; metabolism ; pathology ; Humans ; Polycythemia Vera ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Receptors, Thrombopoietin ; metabolism

BACKGROUNDRecently, calreticulin (CALR) gene mutations have been identified in patients with essential thrombocythemia (ET). A high-frequency of ET cases without Janus kinase 2 (JAK2) mutations contain CALR mutations and exhibit clinical characteristics different from those with mutant JAK2. Thus, we investigated the frequency and clinical features of Chinese patients of Han ethnicity with CALR mutations in ET.

METHODSWe recruited 310 Chinese patients of Han ethnicity with ET to analyze states of CALR, JAK2V617F, and MPLW515 mutations by polymerase chain reaction and direct sequencing. We analyzed the relationship between the mutations and clinical features.

RESULTSCALR, JAK2V617F, and MPLW515 mutations were detected in 30% (n = 92), 48% (n = 149), and 1% (n = 4) of patients with ET, respectively. The mutation types of CALR involved deletion and insertion of base pairs. Most of them were Type 1 (52-bp deletion) and Type 2 (5-bp insertion, TTGTC) mutations, leading to del367fs46 and ins385fs47, respectively. The three mutations were exclusive. Clinically, patients with mutated CALR had a lower hemoglobin level, lower white blood cell (WBC) count, and higher platelet count compared to those with mutated JAK2 (P < 0.05). Furthermore, a significant difference was found in WBCs between wild-type patients (triple negative for JAK2, MPL, and CALR mutations) and patients with JAK2 mutations. Patients with CALR mutations predominantly clustered into low or intermediate groups according to the International Prognostic Score of thrombosis for ET (P < 0.05).

CONCLUSIONSCALR mutations were frequent in Chinese patients with ET, especially in those without JAK2 or MPL mutations. Compared with JAK2 mutant ET, CALR mutant ET showed a different clinical manifestation and an unfavorable prognosis. Thus, CALR is a potentially valuable diagnostic marker and therapeutic target in ET.

Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; genetics ; Biomarkers ; analysis ; Calreticulin ; genetics ; Female ; Humans ; Janus Kinase 2 ; genetics ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Mutation ; Receptors, Thrombopoietin ; genetics ; Thrombocythemia, Essential ; genetics ; pathology ; Thrombosis ; genetics ; Young Adult

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.
Aged ; Amino Acid Substitution ; Asian Continental Ancestry Group/*genetics ; Exons ; Female ; Humans ; Janus Kinase 2/*genetics ; Male ; Middle Aged ; *Mutation ; Polycythemia Vera/genetics ; Receptors, Thrombopoietin/*genetics ; Republic of Korea ; Sequence Analysis, DNA ; Thrombocythemia, Essential/diagnosis/*genetics

OBJECTIVETo investigate the prevalence of JAK2V617F and MPLW515L/K mutation in patients with slightly elevated platelets (BPC) or hemoglobin (Hb) not meeting the criteria of polycythemia vera (PV) or essential thrombocythemia (ET).

METHODSGenomic DNA from bone marrow or blood mononuclear cells was screened with allele specific polymerase chain reaction (AS-PCR) for JAK2V617F and MPLW515L/K mutation. The history of thrombosis was assessed retrospectively by patients files.

RESULTSOf 30 patients, 14 (46.7%) were positive for the JAK2V617F mutation, none of them had the MPLW515L/ K. Five of these 14 patients had a history of thrombosis. Follow-up results were available in 22 patients. Among them, 12 patients with JAK2V617F mutation turned out to be MPD in 6-24 months; only 2 out of 10 patients without this mutation evolved to MPD.

CONCLUSIONJAK2V617F mutation could be one of the diagnosis criteria of early MPD. No MPLW515L/K expression was found in early MPD.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Early Diagnosis ; Female ; Follow-Up Studies ; Humans ; Janus Kinase 2 ; genetics ; metabolism ; Male ; Middle Aged ; Mutation ; Myeloproliferative Disorders ; diagnosis ; genetics ; metabolism ; Receptors, Thrombopoietin ; genetics ; metabolism ; Young Adult

This study was purposed to explore the effect of different cytokine combinations on the expansion of the mononuclear cells drived from umbilical cord blood (CB) ex vivo and expression of CXCR4 and CD49d on CD34+ cells after expansion. Human fresh CB mononuclear cells were cultured in serum-free and stroma-free medium containing different combinations of cytokine for 7 days. At day o and 7, the total cells were counted, CD34+ cells and CD34+CXCR4+, CD34+CD49d+ cells were assayed by flow cytometry, and CFU were determined. According to the different combinations of cytokine, experiments were divided into four groups: control, SF group (SCF + FL), SFT group (SCF + FL + TPO) and SFT6 group (SCF + FL + TPO + IL-6). The results showed that the SF (SF group) combination supported only low expansion of total cells, CD34+ cells and CFU. The addition of TPO in SF group restored UCB stem/progenitors expansion to a higher level than that in SF group, while there was no difference between groups SFT and SFT6 (P > 0.05). The cytokine combinations in groups SF, SFT and SFT6 all could upregulate the expression levels of CD49d and CXCR4 on expanded cord blood CD34+ cells, but there were no significant differences between groups SF, SFT and SFT6 (P > 0.05). It is concluded that SCF + FL has no strong synergistic effects on primitive hematopoietic cells. TPO plays an important role in enhancing expansion of umbilical cord blood hematopoietic cells, while IL-6 only shows a neutral effect on it. SCF + FL + TPO combination not only promotes progenitor cells expansion but also upregulates the expression of CD49d and CXCR4 on CD34+ cells from cord blood.
Antigens, CD34 ; biosynthesis ; genetics ; Cytokines ; pharmacology ; Drug Synergism ; Fetal Blood ; cytology ; Humans ; Integrin alpha4 ; biosynthesis ; genetics ; Leukocytes, Mononuclear ; cytology ; Membrane Proteins ; pharmacology ; Receptors, CXCR4 ; biosynthesis ; genetics ; Stem Cell Factor ; pharmacology ; Thrombopoietin ; pharmacology