JAK2 V617F, MPL W515L and JAK2 Exon 12 Mutations in Chinese Patients with Primary Myelofibrosis.

OBJECTIVE: JAK2 V617F, MPL W515L and JAK2 exon 12 mutations are novel acquired mutations that induce constitutive cytokine-independent activation of the JAK-STAT pathway in myeloproliferative disorders (MPD). The discovery of these mutations provides novel mechanism for activation of signal transduction in hematopoietic malignancies. This research was to investigate their prevalence in Chinese patients with primary myelofibrosis (PMF). METHODS: We introduced allele-specific PCR (AS-PCR) combined with sequence analysis to simultaneously screen JAK2 V617F, MPL W515L and JAK2 exon 12 mutations in 30 patients with PMF. RESULTS: Fifteen PMF patients (50.0%) carried JAK2 V617F mutation, and only two JAK2 V617F-negative patients (6.7%) harbored MPL W515L mutation. None had JAK2 exon 12 mutations. Furthermore, these three mutations were not detected in 50 healthy controls. CONCLUSION: MPL W515L and JAK2 V617F mutations existed in PMF patients but JAK2 exon 12 mutations not. JAK2 V617F and MPL W515L and mutations might contribute to the primary molecular pathogenesis in patients with PMF.

[Detection of complex chromosomal aberrations in patients with multiple myeloma using multiplex fluorescence in situ hybridization].

OBJECTIVE: To explore the value of multiplex fluorescence in situ hybridization (M-FISH) in the detection of the complex chromosomal aberrations (CCAs) in multiple myeloma (MM). METHODS: M-FISH was used in 10 MM patients with CCAs detected by conventional cytogenetics (CC) using R-banding to refine the rearrangement of CCAs and identify the characteristics of marker chromosome. RESULTS: M-FISH confirmed the 29 structural aberrations shown by CC analysis, and also confirmed the specific source of 21 types of chromosomal aberration, which were not detected by CC analysis. Among them, t(2;15)(q33;q22), t(6;7)(q23;q34), t(8;11) (q24;q23), t(1;14)(q10;q32) and t(X;1)(q26;q25) were new chromosomal aberrations. The median survival time of 9 MM patients with CCAs was 23 months and evidently shorter than that of MM patients without CCAs, with the mean survival time being 34 months. CONCLUSION: M-FISH could refine CCAs in MM patients, find or correct the missed or misidentified abnormalities analyzed by CC. It has provided one of the essential methods for the research of chromosomal aberrations in MM.

[Expression of the CDH13 gene and BCR/ABL fusion gene in chronic myeloid leukemia patients and their relationship].

OBJECTIVE: To investigate the expression of the CDH13 gene and BCR/ABL fusion gene in chronic myeloid leukemia(CML) patients at different stages and explore their relationship. METHODS: RNA was isolated from peripheral blood in 30 healthy adults, 22 primary CML patients and 25 blastic crisis of CML patients. We examined the expression of the CDH13 gene and BCR/ABL fusion gene using EVA Green real-time reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: The expression of the BCR/ABL fusion gene in the patients with blastic crisis CML was 4.72 folds as that of the patients with primary CML. The expression of the CDH13 gene in the primary and blastic crisis CML patients was significantly reduced to 36% and 25% of that in healthy controls, respectively. Moreover, negative correlation was found between the expressions of these two genes. CONCLUSION: The study showed that the reduction of the CDH13 expression at different clinical stage of CML may account for the defective cell adhesion in CML, and the expression of the CDH13 gene was probably down-regulated by the BCR/ABL fusion gene.

Effect of low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor priming (CAG regimen) on the outcome of elderly patients with acute myeloid leukemia.

The aim of this study was to evaluate the efficacy and toxicity of low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor (G-CSF) protocol in elderly patients with acute myeloid leukemia (AML). A total of 50 elderly patients including 8 aged over 70 years were enrolled. All patients were treated with CAG regimen including low-dose cytarabine (10mg/m(2) every 12h, days 1-14), aclarubicin (10mg every day, days 1-8), and G-CSF (200 microg/m(2) every day, days 1-14) priming. The overall response rate was 72.0%, and 29 of 50 (58.0%) patients achieved complete remission, including 23 of 35 (65.8%) with previously untreated AML, 6 of 15 (40.0%) with refractory, relapsed or secondary AML, 4 of 8 (50.0%) aged over 70 years, 4 of 10 (40.0%) with unfavorable cytogenetic aberrations. The early death rate was 7.6%. The median overall survival was 14 months. Myelosuppression was mild to moderate, severe nonhematologic toxicity was not observed. Thus CAG priming regimen as the induction therapy is well tolerated and effective in elderly patients with AML.

[Correlations of JAK2V617F point mutation with clinical and laboratory features in patients with polycythemia vera].

To evaluate JAK2V617F point mutation in patients with polycythemia vera (PV) and its clinical significance, the point mutation was detected by allele specific polymerase chain reaction (AS-PCR), and the clinical and laboratory features of 50 PV patients with JAK2V617F positive and negative mutations were analyzed and compared each other. The results showed that among 50 patients, 31 patients (62.0%) had JAK2V617F point mutation; 12 patients (24.0%) showed thrombosis and microvascular disturbances; 3 patients had chromosome karyotype abnormalities. As compared with negative mutation group, the age and leukocyte count in patients with JAK2V617F point mutation were older (57.5 +/- 10.0 vs 45.6 +/- 14.9, p < 0.05) and higher (16.2 +/- 6.7 vs 9.0 +/- 5.2, p < 0.05) respectively. It is concluded that the frequency of the JAK2V617F point mutation is 62.0% in PV patients, the age and leukocyte count of patients with JAK2V617F point mutation are older and higher respectively than those in negative mutation group.

[Detection of circulating and bone marrow myeloma cells in patients with multiple myeloma and its clinical significance].

This study was aimed to investigate the correlation between circulating myeloma cells (CMC) and bone marrow myeloma cells (MMC) in patients with multiple myeloma (MM) and its clinical significance. Four-color flow cytometry was used to detect the percentage of CMC and MMC in 55 patients with MM. Other prognosis-associated factors such as beta(2) microglobulin (beta(2)-MG), serum albumin (Alb), chromosomal abnormalities and renal function were simultaneously analyzed. The patients were divided into four groups: group A, in which CMC and MMC were simultaneously detected; group B, in which only MMC were detected; group C, in which only CMC were detected; group D, in which no myeloma cells were detected in peripheral blood or bone marrow. The results showed that the concentrations of beta(2)-MG and creatinine were significantly increased and Alb markedly decreased in group A as compared with other groups. Statistical differences existed in the above-mentioned factors between patients with myeloma cells detected and not detected. The percentages of CMC or MMC in newly diagnosed, refractory and relapsed patients were apparently higher than those in patients with partial and complete remission, respectively. CMC were strikingly correlated with MMC. It is concluded that the percentages of CMC and MMC not only imply tumor load in MM patients, but also predict the progression of MM, respectively for patients with MM, in those patients CMC and MMC were simultaneously detected.