Clinical efficacy of switching to 2nd generation of tyrosine kinase inhibitor on CML patients at poor responses to imatinib / 中国实验血液学杂志

<p><b>OBJECTIVE</b>This study was to investigate the timing and clinical efficacy of switching to the 2nd generation of tyrosine kinase inhibitor (TKI) for CML patients at poor response to imatinib (dissatifed efficacy or intolerance).</p><p><b>METHODS</b>The therapeatic efficacy and side reaction of switched 2nd TKI in patients with newly diagnsed CML-CP who poorly responded to imatinib were observed, anong them 3 cases were intolerant, 6 cases did not acquire satisfied efficacy.</p><p><b>RESULTS</b>After switching to 2nd generation TKI, 3 patients with intolerance achieved complete cytogenetic remission (CCyR) in 3 months, and major molecular remission (MMR) in 3-6 months. All of them achieved optimal efficacy according to European Leukemia Network (ELN), but the pleural effusion appeared in 1 case after use of 2nd generation of TKI for 3 months, and the dadatinib was stoped temporally, and the curative efficacy still was maintained. Among 6 cases with poor efficacy by treatment with imatinib, 2 cases with BCR/ABL mutation progressed after switching 2nd generation of TKI, out of them 1 case with poor tolerance progeressed to the accelerated phase, but was cured by haploidentical allogeneic hematopoictic stem cell transplantation, 1 case progressed to blastic crisis and died of serious infection; the another 4 cases achieved MMR in 3-12 months after using 2nd generation of TKI, and maintained CMR for 12-36 months.</p><p><b>CONCLUSION</b>CML-CP patients without the optimal response to imatinib should be treated by switching to 2nd generation of TKI as soon as possible, and thereby patients may acquired satisfactory therapentic efficacy.</p>

A case report of refractory pleural effusion associated with dasatinib in the treatment of chronic myeloied leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To study the clinical features and prognosis of pleural effusion associated with dasatinib in treatment of chronic myeloid leukemia(CML).</p><p><b>METHODS</b>A 49 year old mal patient with CML who suffered pleural effusion(grade 3) associated with dasatinib was analyzed and summarized.</p><p><b>RESULTS</b>the patient achieved complete molecular response(CMR) after treating with dasatinib 100 mg once daily for 3 months. However, the symptom of chest distress occured in the patient after dasatinib treatment for 6 months, the chest CT scan showed bilateral pleural effusion(grade 3), the pleural effusion related with dasatinib was diagnosed, therefore the diuretic and steriod drugs were given, thoracocentesis was also used to relieve the symptom, after treatment for 5 weeks the pleural effusion disappeared, but the pleural effusion recurred when the patient taken dasatinib again, thus the dasatimib was permanently discontinued, but the patient was in CMR. Six months later, the patient began to take Imatinib (first TKI) 300 mg/d, good effects were achieved and no serious adverse effects were observed. Up to now, the patient still is in CMR for 20 months.</p><p><b>CONCLUSION</b>In the treatment of CML, appropriate TKI should be chose according to basic disease, and pleural effusion is one of the most common adverse effects during the therapy with dasatinib, close monitoring and timely intervention are necessary. For these patients who were intolerable to recieve the dasatinib, the conversion to another TKI may acquire satisfactory curative effect with tolerance of patients.</p>

Simultaneous detection of FLT3-ITD and NPM1 gene mutations in acute myeloid leukemia by double PCR / 中国实验血液学杂志

Objective of this study was to establish a method for simultaneous detection of FLT3/ITD and NPM1 gene mutations in AML. A double PCR was firstly designed and optimized to amplify both exon 12 of NPM1 and exon 14-intron 14-exon 15 of FLT3, with the aim of detecting almost all reported mutations. After optimization, a touchdown PCR was chosen for the multiplex PCR procedure, with the primer concentrations of NPM1 and FLT3-ITD being 200 nmol/L and 152 nmol/L respectively. The PCR amplicons were separated by capillary electrophoresis and the presence of mutants was recognized by the size difference between the mutants and wild-type products. The areas of mutant peak and wild-type peak were used to calculate the mutant/wild-type ratio. All the positive mutated samples were confirmed by sequencing. The results showed that 17 patients with NPM1 mutation, 15 patients with FLT3-ITD mutation, 6 patients with both NPM1 and FLT3-ITD mutations were found among 93 patents. 7 patients with M₂, 4 patients with M₄, 5 patients with M₅ and 1 patients with M₆ were found out of 17 patients with NPM1 mutation, in which 10 patients were male and 7 patients were female, 15 patients were with type A, 1 patients was with type B and 1 patients was with type Nm, strikingly 1 CML patient in blast crisis was found to carry a type A mutation. Among 15 patients with FLT3-ITD mutation 1 patient with M₁, 8 patients with M₂, 2 patients with M₂, 2 patients with M₃, 1 patient with M₄, 3 patients with M₅ were found, in which 5 patients were male and 10 patients were female. Sequencing results further confirmed the accuracy and reliability of this method. It is concluded that a novel method with the ability to detect both FLT3-ITD and NPM1 mutations has been developed when genomic DNA was templated. This method is fast, easy, accurate and capable to calculate the mutant/wild-type ratio.

Inhibitory effect of phenylhexyl isothiocyanate on notch signaling of multiple myeloma cells in vitro / 中国实验血液学杂志

In order to investigate the mechanisms of phenylhexyl isothiocyanate (PHI) inhibiting the proliferation of multiple myeloma cell RPMI8226 in vitro, the RPMI8226 cells were co-cultured with PHI of various concentrations. The inhibition of proliferation was measured by MTT test and the cell apoptosis was assayed by DAPI staining. The changes of Notch1, Jagged2, BCL-2 and p-Akt proteins in the PHI-treated cells were detected by Western blot. The results showed that PHI inhibited RPMI8226 cell proliferation in certain concentration range and induced their apoptosis. The inhibiting effect caused by PHI showed a concentration-and time-dependent manner. The PHI decreased expressions of Notch1 and Jagged2 proteins in a concentration-and time-dependent manners, the levels of BCL-2 and p-Akt declined at the same time. It is concluded that PHI can inhibit proliferation of RPMI8226 cells, and induce their apoptosis. The cell apoptosis is associated with the inhibition of Notch signaling and downstream targets BCL-2 and p-Akt proteins of RPMI8226 cells, PHI may be a new Notch signaling inhibitor and a promising therapeutic drug for multiple myeloma.

Expression of DNA methyltransferase in myeloma U266 cells and its significance / 中国实验血液学杂志

In order to study the activity and gene expression of DNA methyltransferase (DNMT) on U266 myeloma cells and to analyze their significance, the activity of DNMT was detected by ELISA, and the expressions of DNMT1, DNMT3a and 3b were analyzed by RT-PCR. U266 cells were treated by phenylhexyl isothiocyanate (PHI), and the change of activity and gene expression of DNMT were determined. The results indicated that the activity and expression of DNMT in U266 myeloma cells were higher, compared with normal control. After being treated by different concentration of PHI, U266 cells were driven into apoptosis and the activity of DNMT decreased obviously and the mRNA level of DNMT declined. It is concluded that the activity and gene expression of DNMT on U266 myeloma cells are higher, and DNMT may be a new therapeutic target of multiple myeloma.