Applications of microchip electrophoresis and capillary electrophoresis for screening FLT3-ITD gene mutation in acute myeloid leukemia / 中国实验血液学杂志

The purpose of the present study was to compare the reliability of microchip electrophoresis and capillary electrophoresis for screening FLT3-ITD gene mutation in acute myeloid leukemia. The FLT3-ITD mutation in the genomic DNA samples from 214 untreated AML patients were separately detected by PCR-microchip electrophoresis and PCR-capillary electrophoresis, then the DNA direct sequencing analysis was carried out. The results from PCR-microchip electrophoresis showed that there were 151 FLT3-ITD mutation negative, 58 FLT3-ITD mutation positive (58/214, 27.1%) and 5 FLT3-ITD mutation doubtful positive (5/214, 2.3%), while the outcomes from PCR-capillary electrophoresis displayed that there were 147 FLT3-ITD mutation negative and 67 FLT3-ITD mutation positive (67/214, 31.3%) without doubtful positive. In the 67 FLT3-ITD mutation positive samples detected by using PCR-capillary electrophoresis, 4 samples were detected as the negative while 5 samples were measured as the doubtful positive by using PCR-microchip electrophoresis. The followed sequencing analysis demonstrated that the above 9 samples were all FLT3-ITD mutation positive, indicating that PCR-capillary electrophoresis was more accurate and sensitive in screening the FLT3-ITD mutation, although statistic analysis showed that there were no significant differences in the detected results between PCR-microchip electrophoresis and PCR-capillary electrophoresis groups (Pearson Chi-squared Test, P > 0.05). It is concluded that both PCR-microchip electrophoresis and PCR-capillary electrophoresis were convenient and fast for screening FLT3-ITD mutation, but the accuracy of PCR-microchip electrophoresis awaits further improvement.

Immunophenotypic and clinical characteristic analysis of NPM1 mutated acute myeloid leukemia with a normal karyotype / 中国实验血液学杂志

This study was purposed to compare the immunophenotypic and clinical characteristics of NPM1 mutated acute myeloid leukemia with a normal karyotype under the similar constituent ratio of FAB subtypes. Immunophenotyping and NPM1 gene mutation type-A,B and D and other leukemic related fusion genes were detected by multiparameter flow cytometry and real time RT-PCR or PCR, respectively. 77 AML patients with a normal karyotype (NK) and mutated NPM1 gene (NPM1m(+)AML) detected by immunophenotyping assay were included in this study. 55 cases without NPM1 mutation (NPM1m(-)AML) and with normal karyotype were served as negative control. The results showed that there was significant difference between NPM1m(+)AML and NPM1m(-)AML in terms of sex, white blood count, platelet counts, blast, WT1 expression level, FLT3-ITD mutation positive rate and response to treatment. The characteristic immunophenotype is lower expression of early differentiation-associated antigens (CD34, HLA-DR, CD117, CD38), lymphocytic antigens (CD7, CD4, CD19, CD2) and higher expression of CD33 and CD123 (P < 0.05). When above features was further analyzed between the M1/2 and M4/5 subgroups in NPM1m(+)AML patients, the M1/2 cases retained a higher frequency in women and a higher WT1 expression level (P < 0.05) . Monocytic differentiation-associated antigens including HLA-DR and lymphocytic antigens CD7 were higher expressed and CD117 was lower expressed in M4/5 subgroup (P < 0.05). It is concluded that under condition of similar constituent ratio of M1/2 and M4/5 subtype and normal karyotype, NPM1m(+)AML patients have higher WT1 expression level and better response to treatment. The major immunophenotype features of NPM1m(+)AML patients are lower expression of early differentiation antigens and lymphoid lineage antigens and higher expression of CD33 and CD123. Monocytic differentiation-associated antigens only higher are expressed in M4/5 cases when compared with M1/2 cases within NPM1m(+) AML patients.

The immunophenotypic and clinical characteristics of NPM1 mutated acute myeloid leukemia patients / 中华血液学杂志

<p><b>OBJECTIVE</b>To compare the immunophenotypic and clinical characteristics between NPM1 mutated acute myeloid leukemia (AML) (NPM1m(+)AML) and unmutated AML(NPM1m(-)AML) not otherwise characterized (NOS) under similar FAB subtypes constituent ratio.</p><p><b>METHODS</b>Immunophenotyping and NPM1 gene mutation type-A, B and D and other leukemic related fusion genes were detected by multiparameter flow cytometry and real time RT-PCR or PCR, respectively. 104 AML patients with NPM1m(+)AML and performed immunophenotyping assay were included, 97 with NPM1m(-)AML.</p><p><b>RESULTS</b>There were significant difference between the two groups at presentation in terms of sex, white blood count(WBC), platelet counts (PLT), blast ratio, normal karyotype ratio, WT1 expression level, FLT3-ITD mutation positive rate and remission rate of first course of induction therapy (P < 0.05). On the immunophenotype, the expression of early differentiation antigens (CD34, HLA-DR, CD117, CD38), lymphocytic antigens (CD7, CD4, CD19, CD2), myeloid and monocytic differentiation-associated antigens (CD13, CD14, CD15) were lower, and that of CD33 as well as CD123 were higher in NPM1m(+)AML patients. Among them, only CD34, HLA-DR, CD7, and CD4 positive cases were significantly lower in NPM1m(+)AML group than in NPM1m(-)AML group (P < 0.05), the rest of them had significant difference in the number of positive cells (P < 0.05). Above features were further analyzed between the M1/M2 and M4/M5 subgroups. M1/M2 cases retained the women prominent and had a higher WT1 expression level (P < 0.05). The expression of monocytic differentiation-associated antigens including HLA-DR and lymphocytic antigens were higher and that of CD117 were lower in M4/M5 subtype (P < 0.05). Among them, the positive rates of HLA-DR, CD64, CD11b, CD10, CD15, and CD4 were significantly higher in M4/M5 than in M1/M2 in NPM1m(+)AML group (P < 0.05).</p><p><b>CONCLUSION</b>The most clinical characteristics in NPM1m(+)AML patients are consistent with reports, but some immunophenotype are different to the previous reports under similar FAB subtypes constituent ratio. The major immunophenotypic features of NPM1m(+)AML patients are lower expression of progenitor, myeloid and lymphoid lineage antigens. Monocytic differentiation-associated antigens are only higher expression in M4/M5 cases when comparison with M1/M2 cases within NPM1m(+)AML group.</p>

Abnormally lower expression of cmtm5 gene in bone marrow cells from patients with multiple myeloma / 中国实验血液学杂志

This study was aimed to detect the expression level of cmtm 5 (CKLF-like MARVEL transmembrane domain containing member 5) gene in the bone marrow cells from patients with multiple myeloma (MM), and to investigate the correlation between the expression level of cmtm5 and various clinical characteristics. Real-time quantitative reverse transcription polymerase chain reaction (RQ-RT-PCR) was used to measure the expression levels of cmtm5 gene in the bone marrow cells collected from MM patients, and the MM cell lines, namely, RPMI8226 and CZ1 cells. The normal donor marrow specimens were used as the reference. The ratio of cmtm5 copy number to abl (Abelson murine leukemia viral oncogene homolog) gene copy number was used for indicating the expression level. The results showed that the expression level of cmtm5 gene was significantly down-regulated in bone marrow cells of 51 untreated or relapsed/refractory MM patient as compared to those of normal donor marrow cells (0.047+/-0.062 for the untreated or relapsed/refractory MM patients versus 0.255+/-0.333 for the normal, p<0.01). According to the International Staging System (ISS), the cmtm5 expression level in marrow cells of patients in ISS III stage was significantly lower than that in patients in ISS I stage (0.034+/-0.034 for the ISS III stage versus 0.103+/-0.109 for ISSI stage, p<0.01). Similarly, lower expression levels of cmtm5 gene were also found in two human MM cell lines (0.014+/-0.009 for RPMI8226 cells and 0.004+/-0.006 for CZ1 cells). After the MM patients were effectively treated, their expression levels of cmtm5 gene significantly increased (0.020+/-0.005 for the untreated patients versus 0.227+/-0.038 for the effectively treated patients, p<0.01). A significant negative correlation was observed between the expression level of cmtm5 gene and the number of bone marrow plasma cells (r=-0.307, p<0.05). However, the correlation was not found between the expression level of cmtm5 gene and the clinical characteristics, such as gender, age, hemoglobin level, or M-protein level, etc. It is concluded that the expression level of cmtm5 gene is abnormally lower in the bone marrow cells from the MM patients, and are associated with ISS stages. Furthermore, the expression level of cmtm5 gene is negatively correlated with the number of bone marrow abnormal plasma cells in MM patients, which suggests that the abnormally lower expression of cmtm5 may be involved in the pathogenesis of the MM patients.

Abnormal expression of programmed cell death 5 gene in multiple myeloma patients / 中国实验血液学杂志

The aim of this study was to investigate the gene expression of programmed cell death 5 (pdcd5) in plasma and bone marrow cells from patients with multiple myeloma (MM). Enzyme liked immunosorbent assay (ELISA) and real-time quantitative reverse transcription polymerase chain reaction (RQ-RT-PCR) were used to examine pdcd5 gene expression in plasma and marrow cells in 45 MM patients and 20 normal controls. The results showed that serum levels of PDCD5 protein in 45 MM patients were lower significantly compared with the normal controls and 20 responsive patients after chemotherapy, their plasma levels were (16.91 +/- 0.28) ng/ml, (19.11 +/- 0.29) ng/ml and (17.94 +/- 0.154) ng/ml respectively (p < 0.05). The pdcd5 gene expression levels detected by RQ-RT-PCR in 45 MM patients were lower significantly compared with the normal controls, their pdcd5 gene expression levels were 0.64 +/- 0.47 and 1.28 +/- 1.21 respectively (p < 0.05). It is concluded that the PDCD5 protein expression levels are low in patients with MM. These findings suggest that abnormal expression of pdcd5 may be involved in the pathogenesis of MM.

Synergistic killing effect of the conditionally replicating adenoviruses carrying programmed cell death 5 gene and etoposide on K562 cells / 中国实验血液学杂志

The expression levels of programmed cell death 5 (PDCD5) are down-regulated in many malignancies. SG611-pdcd5, a recombinant conditionally replicative adenovirus carrying pdcd5 gene expression cassette, can evidently kill the leukemic cells and protect selectively the normal cells. The purpose of this study was to investigate the synergistic killing effect of SG611-pdcd5 and low-dose etoposide (VP-16) on K562 cells. K562 cells were treated with different concentrations of VP-16 or different multiplicities of infection (MOI) of SG611-pdcd5. After 48 hours of incubation the cell viability was determined by using MTT assay. The results showed that the cell viability of SG611-pdcd5 (MOI = 40) plus VP-16 (0.5 µg/ml) group significantly decreased as compared with single SG611-pdcd5 (MOI = 40) treatment group or single VP-16(0.5 µg/ml) treatment group (42.00 ± 5.75% vs 59.45 ± 4.12%; 42.00 ± 5.75% vs 82.91 ± 3.41%, respectively, both p < 0.05). The synergistic killing effect of SG611-pdcd5 plus VP-16 was higher than that of PDCD5 protein plus VP-16 or that of non-replicating adenovirus carrying pdcd5 (Ad-pdcd5) plus VP-16 (both p < 0.05). The cell viability of VP-16 (4.0 µg/ml) plus SG611-pdcd5 (MOI = 40) group, VP-16 (4.0 µg/ml) plus proPDCD5 (40 µg/ml) group and VP-16 (4.0 µg/ml) plus Ad-pdcd5 (MOI = 80) group was 37.09 ± 1.89%, 52.36 ± 1.64% and 73.64 ± 4.33%, respectively. It is concluded that SG611-pdcd5 can promote K562 cell death induced by low-dose VP-16. The combination of SG611-pdcd5 and VP-16 can enhance the killing effect on leukemic cells.

The clinical characteristics of newly diagnosed acute myeloid leukemia patients with NPM1 mutation / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the clinical characteristics of newly diagnosed acute myeloid leukemia (AML) with NPM1 mutation.</p><p><b>METHODS</b>NPM1 mutation (including A, B, D mutation type) was detected in 206 patients with newly diagnosed AML by real-time quantitative RT-PCR.</p><p><b>RESULTS</b>The incidence of NPM1 mutation was 15.5% in total AML patients and 32.5% in normal karyotypes AML patients. The characteristics of 174 NPM1 wild type patients v.s. that of 32 NPM1 mutation patients was as follow, median age (46 vs 35 years old, P < 0.01), WBC counts (27 × 10(9)/L vs 8 × 10(9)/L, P < 0.01), BPC (82 × 10(9)/L vs 36 × 10(9)/L, P < 0.01), proportion of AML-M(5) (31.2% vs 5.8%, P = 0.01), incidence of normal karyotypes (92.6% vs 40.8%, P < 0.01), incidence of FLT3-ITD-positive (25.0% vs 7.5%, P < 0.01), CD34-positvie (23.3% vs 69.5%, P < 0.01), cases with fusion gene (0 vs 47.1%, P < 0.01). No statistic difference was found in sex, percentage of blasts in bone marrow, complete remission rate, overall survival between the two groups. Relapse-free survival in AML patients with NPM1-mutation and FLT3-ITD-negative tended to be higher than in those with NPM1-mutation and FLT3-ITD-positive.</p><p><b>CONCLUSION</b>It is necessary to detect NPM1 mutation and FLT3-ITD in newly diagnosed AML patients, especially in patients with high WBC and BPC, CD34-negative, normal karyotype, which might help to molecular classification and treatment.</p>

Expression of 5 genes in CD7 positive acute myeloid leukemia stem/progenitor cells from bone marrow / 中国实验血液学杂志

This study was aimed to investigate abca5, mdr-1, kdr, dapk and irf-1 expressions in leukemia stem/progenitor cells (LSC) from CD7 positive acute myeloid leukemia, the expression of these 5 genes in mononuclear cells (MNC) from 15 normal bone marrow (NBM) and 16 AML patients bone marrow (AML BM) specimen were detected by real-time quantitative PCR (RQ-PCR). CD34(+)CD38(+) progenitor cells and CD34(+)CD38(-)Lin(-) stem cells were sorted by flow cytometry (FCM) from the MNCs of 10 NBM and 21 AML BM specimen. These 5 gene expressions in the sorted cells were detected by small amount cell RQ-PCR. The results showed that these 5 genes above mentioned all expressed in NBM-MNC, in which the expression levels of irf-1 and dapk were highest with the relative expression levels 4.08 and 3.86, the expression levels of abca 5 and mdr-1 were in the middle with the relative expression 0.49 and 0.84 respectively, the kdr expression was lowest with the relative expression level 0.02. In CD34(+)CD38(+) progenitor cells, the expression level of kdr increased dramatically (p < 0.05) while irf-1 and dapk dramatically decreased (p < 0.05). There was no obvious change of expression in the rest 2 genes. In CD34(+)CD38(-) stem cells the expression level of these 5 genes all increased nearly 2 times as much as that in CD34(+)CD38(+) progenitor cells, but kdr increased 3 times as much, and the increase of kdr and irf-1 expressions was of statistical significance (p < 0.05). Compared with the NBM, expression levels of 5 genes in AML-MNC decreased, and out of them abca 5, mdr-1, kdr and dapk were decreased most remarkably (p < 0.05). Comparison between AML CD34(+)CD38(+) cells and AML MNC showed that the expression level of irf-1 and dapk were decreased dramatically (p < 0.05) while the rest 3 genes increased their expression with statistical significance (p < 0.05). The expression levels of these 5 genes were higher in CD34(+)CD38(-) cells than those in CD34(+)CD38(+) stem cells, and the increase of kdr and irf-1 expressions showed statistical difference (p < 0.05). These 5 genes expression levels were all higher than those in CD34(+)CD38(+) cells whether in AML CD34(+)CD38(-)CD7(+) cells or CD34(+)CD38(-)CD7(-) cells. The increase of kdr expression in CD34(+)CD38(-)CD7(+) cells as well as kdr and irf-1 expressions in CD34(+)CD38(-)CD7(-) cells were all of statistical significance (p < 0.05). In conclusion the expression level of kdr in NBM was highest in stem cells while dapk and irf-1 were highest in differentiated cells. The expression levels of these 5 genes in CD34(+)CD38(-)Lin(-) stem cells were higher than those in CD34(+)CD38(+) progenitor cells. The gene expressions in AML CD34(+)CD38(-)CD7(+) cells and CD34(+)CD38(-)CD7(-) cells are in accordance with the characteristics of stem cells.

Construction and verification of a novel triple-regulated oncolytic adenovirus carrying gene Pdcd5 / 中国实验血液学杂志

The purpose of this study was to construct a recombinant conditionally replicating adenovirus (CRAd) expressing programmed cell death 5 (pdcd5). Pdcd5 gene was inserted in the E3 region of SG600-a CRAd in which the key genes for virus replication E1a and E1b were controlled under the human telomerase reverse transcriptase promoter (hTERTp) and the hypoxia response element (HRE) respectively, and with a deletion of 24 nucleotides within CR2 region of E1a. The insertion and orientation of all recombined plasmids were confirmed by restriction enzyme digestion and polymerase chain reaction (PCR). The infection efficiencies of a recombined virus carrying enhanced green fluorescent protein (EGFP) in leukemic cell lines were observed by using fluorescence microscope. The relative pdcd5 expression levels of K562 after being infected with SG611-pdcd5 were detected by real-time quantitative PCR. The results showed that the construction of SG611-pdcd5 was completed and confirmed. Pdcd5, hTERTp, HRE, skeleton and fiber11 of recombinant adenovirus SG611-pdcd5 were successfully amplified. The infection efficiencies of SG611-EGFP were all above 70% in both leukemic K562 and MEG-01 cell lines. SG611-pdcd5 expressed pdcd5 with high efficiency in leukemic cells as compared with Ad-pdcd5 or SG611 (p < 0.001). The expression level of pdcd5 increased gradually along with the increase of MOI. It is concluded that the triple-regulated adenovirus of SG611-pdcd5 containing the pro-apopro-tic gene pdcd5 has been successfully established with high pdcd5 expression level in leukemic cells, indicating that the recombinant adenovirus, SG611-pdcd5, promises further development of targeted tumor gene therapy.

Abnormal expression of PDCD5 in the bone marrow cells of adult acute myeloid leukemia / 中国实验血液学杂志

The objective of this study was to estimate a novel apoptosis-promoting molecule PDCD5 expression in the bone marrow cells from adult acute myeloid leukemia (AML) for investigation of its significance in the pathogenesis of AML. Flow cytometry assay was used for detection of PDCD5 expression in the different groups of cells from bone marrow of AML patients and normal controls by using 21 monoclonal antibodies with different fluorescent markers. The PDCD5 expressions in bone marrow cells from some AML patients and normal controls were also detected by Western blot. The results showed that the mean PDCD5 fluorescence intensity in bone marrow nucleated cells (MNC) from the bone marrow of 36 untreated AML patients was significantly lower than that from the bone marrow of 30 normal controls (3059 +/- 1392) vs (7432 +/- 1261) (P < 0.01). The mean PDCD5 fluorescence intensity was lower in the marrow granulocytes, monocytes, blast cells, and lymphocytes from untreated AML patients than that from normal (3939 +/- 2121) vs (8367 +/- 1045); (3156 +/- 1635) vs (5917 +/- 2329); (2824 +/- 1592) vs (3998 +/- 2106); (1474 +/- 816) vs (3355 +/- 2042) respectively, (all P < 0.01). Western blot analysis demonstrated that PDCD5 expression was significantly decreased in the AML cells, as compared with normal cells. It is concluded that PDCD5 expression in MNC in untreated AML patients is lower than that in the normal. PDCD5 expression in the marrow granulocytes, monocytes, blast cells, and lymphocytes of untreated AML patients is significantly lower than that in the normal. It suggests that the abnormally low expression of PDCD5 may be involved in the pathogenesis of AML.

Detection of common fusion transcript levels in untreated leukemia patients by real-time quantitative RT-PCR technique / 中华血液学杂志

<p><b>OBJECTIVE</b>To evaluate levels of common specific fusion transcripts M-bcr-abl, m-bcr-abl, TEL-AML1, AML1-ETO, PML-RAR alpha, CBF beta-MYH11 in untreated leukemia patients.</p><p><b>METHODS</b>Specific fusion transcript levels were detected by TaqMan-based real-time quantitative RT-PCR technique in a total of 208 samples, including 195 bone marrow samples from 50 M-bcr-abl(+) chronic phase-chronic myeloid leukemia (CML-CP), 10 M-bcr-abl(+) acute lymphoblastic leukemia (ALL), 19 m-bcr-abl(+) ALL, 11 TEL-AML1(+) ALL, 30 AML1-ETO(+) acute myeloid leukemia (AML), 58 PML-RAR alpha(+) acute promyelocytic leukemia (APL) and 17 CBF beta-MYH11(+) AML patients and 13 peripheral blood samples from 13 M-bcr-abl(+) CML-CP patients. abl was chosen as internal control gene. Fusion transcript level was calculated as fusion transcript copies/abl transcript copies in percentage.</p><p><b>RESULTS</b>Bone marrow and peripheral blood samples of CML-CP patients had similar M-bcr-abl fusion transcript levels (median 30% vs 35%, P > 0.05). M- and m-bcr-abl (median 64% vs 54%) levels were similar in ALL patients (P > 0.05), M-bcr-abl level was significantly higher in ALL than CML-CP patients(P < 0.001). Median TEL-AML1 level was 228% in ALL patients. Among AML patients, AML1-ETO level was significantly higher than CBF beta-MYH11 and PML-RAR alpha levels (median 388% vs 145%, 388% vs 47%, all P < 0.001), CBF beta-MYH11 level was significantly higher than PML-RAR alpha level (P < 0.001). Fusion transcript levels of L-, V- and S-type PML-RAR alpha were 45%, 44% and 55%, respectively. L-type was significantly lower than S-type (P = 0.04).</p><p><b>CONCLUSIONS</b>Fusion transcript levels in untreated leukemia patients were different and patient-to-patient variations did exist. Detection of fusion transcript levels in untreated leukemia patients not only provides baseline for minimal residual disease monitoring and treatment evaluation but also enable the comparison in inter-laboratory data.</p>

Adenovirus-mediated PDCD5 gene transfer sensitizes apoptosis of K562 cells induced by etoposide / 中国实验血液学杂志

This study was purposed to investigate the effect of adenovirus-mediated transfer of PDCD5 gene on apoptosis of K562 cells induced by etoposide. Recombinant adenovirus PDCD5 (Ad-PDCD5), control vectors Ad-null and Ad-eGFP were constructed by AdMax vector system respectively. After K562 cells were transfected by Ad-PDCD5, Ad-null or Ad-eGFP with different multiplicity of infection (MOI), the expression level of the PDCD5 gene was examined by RQ-RT-PCR assay. The effects of etoposide in combination with Ad-PDCD5 on the proliferation and apoptosis of K562 cells were measured by using MTT assay and flow cytometry with Annexin-V-FITC/PI dual labeling technique, respectively. The results showed that the transfection efficiencies of Ad-eGFP in K562, Jurkat and CEM cells ranged from 60% to 86%. Expression level of PDCD5 gene in K562 cells was evidently increased following transfection with Ad-PDCD5. The Ad-PDCD5 synergistically enhanced the apoptotic percentage of K562 cells induced by VP-16, as compared with that of Ad-null + VP16 and VP-16 alone respectively. It is concluded that Ad-PDCD5 may be a potential agent for enhancing the chemotherapy effect.

Detection of phosphotyrosine in bcr-abl-positive cells with PY20 antibody and its clinical applications / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the specificity of anti-phosphotyrosine monoclonal antibody PY20 in bcr-abl+ cells and its possible clinical applications.</p><p><b>METHODS</b>Bcr-abl cell lines( K562, MEG-01) and bcr-abl- cells lines( Jurkat, MCF-7 )were stained with PY20. Phosphotyrosine protein of K562 and MEG-01 cells was detected by flow cytometry before and after treatment with imatinib. Phosphotyrosine protein in bone marrow cells from 49 patients with chronic myeloid leukemia (CML), Ph+ acute lymphoblastic leukemia(Ph(+) -ALL), Ph- ALL, acute myeloid leukemia (AML-M1, M2, M3, M5, FAB classification), chronic lymphocytic leukemia (CML) and 3 normal donor. Positive cells over 5% of total cells was considered positive cases for phosphotyrosine protein. The level of tyrosine phosphorylation was determined by median fluorescence intensity (MFI).</p><p><b>RESULTS</b>Bcr-abl cell lines and marrow cells from 10 CML patients and 8 ALL patients were all PY20-positive, while bcr-abl- cell lines and marrow cells from 18 leukemia patients and 3 normal donor were all PY20-negative. MFI decreased remarkably after blocked by imatinib in K562 cells and MEG-01 cells. The positive cell percent of marrow cells from 10 newly diagnosed CML patients and 9 imatinib-sensitive CML patients was (54.20 +/- 19.82)% and (14.84 +/- 6.17)% (P < 0.05), while that of 2 cases of imatinib-resistant was 64.3% and 57.2%. There was significant difference of MFI between imatinib-resistant patients and imatinib-sensitive patients (99.42 +/- 4.87 vs 46.41 +/- 4.67, P < 0.01).</p><p><b>CONCLUSION</b>PY20 monoclonal antibody is highly specific for bcr-abl+ cells. It might be useful in rapid detection of bcr-abl+ cells and sensitivity to imatinib of CML patients.</p>

Monitoring bcr-abl mRNA levels by real-time quantitative RT-PCR in chronic myeloid leukemia patients after hematopoietic stem cell transplantation / 中华血液学杂志

<p><b>OBJECTIVE</b>To evaluate the value of real time quantitative RT-PCR (Q-PCR) for monitoring bcr-abl mRNA levels in chronic myeloid leukemia (CML) patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT).</p><p><b>METHODS</b>Quantification of bcr-abl mRNA was performed on 316 bone marrow samples from 112 patients with CML after HSCT by Q-PCR using the TaqMan probe system. The bcr-abl mRNA level was normalized by control gene abl. Cytogenetic response was evaluated with fluorescent in-situ hybridization (FISH).</p><p><b>RESULTS</b>The reproducible sensitivity of Q-PCR was 5 copies. The coefficients C(T) of interassay and intraassay variation for abl and bcr-abl were all below 2.0%. 289 bone marrow samples were collected from 101 CML patients who achieved a sustained complete cytogenetic response (CCyR) one month post allo-HSCT in a period of 6 - 60 months (median 12 months) at different intervals. In general, the median bcr-abl levels gradually decreased with the prolongation of time after HSCT: the median bcr-abl levels were 0.035% (0 - 0.406%) at 1 month post allo-HSCT (+ 1 month), 0.006% (0 - 0.683%) at +3 month, 0% (0 - 0.225%) at +6 month and remained 0% till +24 months. The highest level in CCyR patients detected at + 6 month was 0.068%. The bcr-abl mRNA level was decreased by 3 log in sustained CCyR patients at + 1 month compared with the newly diagnosed CML-CP patients (33.0%, data unpublished). On the contrary, Q-PCR results ranged from 0.12% to 13.45% in 8 cytogenetic non-responders or relapsed patients post allo-HSCT. Among them, 5 patients' samples were collected 1 - 2 months before cytogenetic relapse, the results were ranged from 0.09% to 3.42%. If 0.09% was assumed 0.09% as a threshold, 9 sustained CCyR patients (8.9%) were tested once higher than that within 6 month after HSCT but decreased to 0% eventually. 2 blast crisis patients achieved CCyR within 1.6 and 3 months after HSCT, but hematological relapse occurred after 1 and 1.5 months, and their bcr-abl mRNA levels increased dramatically from 0% and 0.14% to 46.9% and 75.9% respectively.</p><p><b>CONCLUSIONS</b>Q- PCR is a sensitive, precise and reliable technique, and can be used to monitor CML patients post allo-HSCT regularly. Patients in blast phase of CML should be monitored more frequently.</p>

Monitoring bcr/abl mRNA levels in imatinib mesylate treated chronic myeloid leukemia patients by real-time quantitative RT-PCR / 中华血液学杂志

<p><b>OBJECTIVE</b>To quantify bone marrow bcr/abl mRNA levels in imatinib mesylate treated Ph chromosome positive chronic myeloid leukemia (CML) patients.</p><p><b>METHODS</b>Serial monitoring of bcr/abl mRNA levels by real-time quantitative RT-PCR technique (RQ-PCR) was performed in 34 cases (120 samples) of CML treated with imatinib mesylate. All the patients were IFNalpha based treatment failure before enrolled in this study and the percentage of Ph(+) bone marrow cells were over 95%.</p><p><b>RESULTS</b>The sensitivity of RQ-PCR was 10 pg RNA, with both coefficients of interassay and intraassay variation below 5% for standard samples. The median bcr/abl mRNA level of 10 patients' samples pre imatinib treatment was 5.79% with marked variation (0.24%-60.90%). In 72 samples post imatinib treatment, which the rates of Ph(+) cells [Ph(+)%] were between 0 and 94%, the mRNA level well correlated with Ph(+)% (r = 0.82, P < 0.001). The mRNA levels of 7 patients who achieved complete cytogenetic response (CCyR) within 12 months decreased markedly, the levels of 6 analysable patients decreased by 65.9% - 98.8% after 3 months'treatment accordingly. The level further decreased to 0 after achieving CCyR. For 4 patients who achieved major cytogenetic response (Ph(+) cells < 35%) later than 12 months, the mRNA levels decreased slowly. The levels of 3 analysable patients on 3 month therapy decreased by 2.5%, 18.5% and 61.6% compared with that before treatment. Out of 5 patients in chronic phase without cytogenetic response, 1 decreased, 2 increased gradually and 2 had no change. In 4 disease progression patients, the levels increased stepwise.</p><p><b>CONCLUSIONS</b>Serial quantifications of bcr/abl mRNA levels are necessary for imatinib treated patients, and are more informative than a single detection. A sharp decline of bcr/abl mRNA levels after the treatment implies a promise of CCyR.</p>

Significance of quantification of WT1 mRNA for monitoring minimal residual disease in acute myeloid leukemia patients / 中华血液学杂志

<p><b>OBJECTIVE</b>To evaluate the significance of quantification of WT1 mRNA for monitoring minimal residual disease (MRD) in patients with acute myeloid leukemia (AML).</p><p><b>METHODS</b>WT1 mRNA level was detected with real-time quantitative RT-PCR (RQ-PCR) technique in bone marrow samples from 15 normal subjects (NBM) and 123 AML patients. Sixty-two AML samples were also detected AML1-ETO mRNA expression by RQ-PCR. Simultaneously follow-up of WT1 and AML1-ETO levels were carried out in 50 samples from 8 AML patients. WT1 and AML1-ETO levels were normalized by internal control ABL gene.</p><p><b>RESULTS</b>All correlation co-efficiencies were over 0.99 for WT1, AML1-ETO and ABL standard curves. Co-efficiencies of both interassay and intraassay variation were below 4%. The WT1 expression levels in NBM were 0.001 to 0.019 with a median level of 0.008. Higher levels of WT1 expression were found in 61 of 67 (91%) newly diagnosed AML patients compared with NBMs and 37 of the 67 (55.2%) showed 100-fold higher WT1 levels than that in NBMs. WT1 mRNA levels were highest in M(4EO) and M(3) and lowest in M(1) and M(5) patients. There was an excellent correlation between WT1 and AML1-ETO gene expression levels (r = 0.88, P < 0.001). WT1 expression levels in three patients who were in continuous complete hematological remission (CHR) were within normal range. In three of four relapsing patients, WT1 expression levels increased 31.4, 11.4 and 4.0 fold respectively one month before hematological relapse.</p><p><b>CONCLUSIONS</b>Quantification of WT1 expression level by RQ-PCR may be used to monitor MRD for most AML patients, but it is less sensitive than fusion gene. Continuous or significant increase of WT1 expression in CHR patients predicts an impending relapse.</p>

Two Ph chromosome positive chronic myelogenous leukemia patients with rare bcr/abl fusion gene / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the unusual bcr/abl fusion gene structures of two Ph chromosome positive chronic myelogenous leukemia (CML) patients in chronic phase (CP).</p><p><b>METHODS</b>By using general M- and micro -bcr/abl specific primers respectively, bcr/abl fusion transcripts were detected by reverse transcription-polymerase chain reaction (RT-PCR). The RT-PCR products sequencing was performed, the DNA sequences were analyzed in Genebank and the bcr and abl sequences at the fusion site were identified. DNA was amplified by PCR using a set of primers designed according to the sequencing result of RT-PCR products.</p><p><b>RESULTS</b>Two patients showed typical manifestations of CML-CP. Their RT-PCR products were different from usual M- or micro -type; one was longer than M-bcr/abl but shorter than micro -bcr/abl, the other one was shorter than M-bcr/abl. The RT-PCR products sequencing showed that both products contained bcr and abl gene sequences. The first patient's bcr gene was broken within exon 18, and fused to abl gene exon 2(a2), and a 40 bp of partial abl intron 1b fragment was inserted between them, resulting in a novel in-frame bcr/abl fusion transcript-e18-int-a2 which has not been reported in the literature so far. In the second patient, deletion of abl exon2(a2) led to exon 13(b2) of bcr gene fusing with abl exon 3(a3).</p><p><b>CONCLUSION</b>Uncommon bcr/abl fusion gene may occur in typical Ph(+) CML patient.</p>

The significance of intracellular IL-1ra expression in the bone marrow cells from adult chronic myelogenous leukemia / 中国实验血液学杂志

To estimate intracellular interleukin-1 receptor antagonist (icIL-1ra) expression in the bone marrow cells from adult patients with chronic myelogenous leukemia (CML), flow cytometry (FCM) assay was used for detecting the mean icIL-1ra fluorescence intensity per cell (equivalent to it's expression level) in different groups of cells from normal and CML patient bone marrows by 15 monoclonal antibodies with different fluorescent marker. The results showed that all of marrow nucleated cells express IL-1ra, but its expression level in granulocytes was the highest and that in lymphocytes was the lowest. The icIL-1ra expression level was significantly lower in nucleated marrow cells, granulocytes and lymphocytes from the marrow of 17 untreated CML patients than that from the marrow of 8 normal. The mean icIL-1ra fluorescence intensity was significantly lower in marrow nucleated cells, granulocytes and lymphocytes in 13 CML patients with marrow blasts >or= 10% than that in 43 CML patients with marrow blasts < 5% or than that in 9 CML patients with marrow blasts 5% - 10%. It was concluded that the lower expression of icIL-1ra in CML marrow nucleated cells might be involved in the evolution of CML.

Analysis of immunophenotype of B-lineage acute lymphoblastic leukemia cells by 4-color flow cytometry / 中国实验血液学杂志

To investigate the characteristics of immunophenotype of B-lineage acute lymphoblastic leukemia (B-ALL) cells in Chinese cases, B-ALL cells from 181 patients were analyzed by 4-color flow cytometry with CD45/SSC gating. The results demonstrated that the antigen expression frequencies were as follows: CD19 (100%), HLA-DR (98.9%), CD38 (88.5%), CD10 (76.8%) and CD34 (76.8%). CD117 and T antigens (CD2 and CD7) were rarely expressed. Childhood group (<or= 14 years) had the highest frequency of CD10. Adolescent (15 - 18 years) and adult groups (>or= 19 years) had a higher expression rate of myeloid antigens (CD13 and/or CD33). Subtype CD10(+)/CD34(+) took the highest percentage in three age groups. Percentages of CD10(-)/CD34(+) group increased by age. Subtype CD10(-)/CD34(+) had the highest myeloid antigen co-expression. Comparing with CD45-positive cases, those with CD45-negative or CD45(+/-) always had higher CD10 expression. Bcr/abl mRNA was evaluated in 43 samples from patients with B-ALL. Myeloid antigen co-expression was not different in bcr/abl(+) and bcr/abl(-) groups, and m-bcr/abl(+) was mainly observed in subtype CD10(+)/CD34(+). In conclusion, typical B-ALL cells expressed CD19(+), HLA-DR(+), and CD117(-). CD34, CD10 and CD45 expression varied in different maturation stages. The immunophenotypic subtype of B-ALL in adolescents was similar to that in the adults. Blasts with CD45(+) were mostly seen in CD10(-) cases. CD13 and/or CD33 co-expression was fewer in children patients. m-bcr/abl(+) was mainly seen in subtype CD10(+)/CD34(+).

Immunophenotypic features of bcr/abl fusion transcript-positive B-lineage acute lymphoblast leukemia / 中国实验血液学杂志

To investigate the biological features of leukemic cells in bcr/abl fusion transcript-positive B-lineage acute lymphoblastic leukemia (B-ALL), 3- or 4-color flow cytometry with directly conjugated monoclonal antibodies was used to detect the immunophenotype of the cells in 26 patients with bcr/able-positive B-ALL and 32 patients with bcr/abl-negative B-ALL. bcr/abl fusion transcript was detected by RT-PCR. Immunoglobulin heavy chain (IgH) gene rearrangement was detected by PCR. The results showed that all of the B-ALL patients were positive for CD19. There was significant difference in expression of CD34 (96.2% vs 65.6%), CD10 (96.2% vs 71.8%) and CD38 (43.8% vs 95.4%) between bcr/abl-positive and -negative groups. In bcr/abl-positive B-ALL group, the co-expression rates of CD10(+)/CD19(+)/CD34(+), CD10(+)/CD34(+)/HLA-DR(+) and CD10(+)/CD34(+)/CD38(-) were 92.3% (24/26), 73.1% (19/26) and 56.2% (9/16), respectively. In bcr/abl-negative group, co-expression of CD10(+)/CD19(+)/CD34(+) and CD10(+)/CD34(+)/HLA-DR(+) were 43.8% (14/32) and 37.5% (12/32), respectively, there were significant differences (P < 0.05) between bcr/abl-positive and -negative groups, but none of the cases co-expressed CD10(+)/CD34(+)/CD38(-). The detection rate of monoclonal IgH gene rearrangement (58.8%, 10/17) was lower in bcr/abl-positive group than that (85.7%, 12/14) in bcr/able-negative group. It is concluded that the expression rates of CD34 and CD10 are higher, and CD38 and IgH gene rearrangement are lower in bcr/abl-positive B-ALL cases, CD10(+)/CD34(+)/CD38(-) is a unique feature of immunophenotype, and this phenotype of leukemia cells is closer to that of early B-lineage progenitor cells.