[Frequently ABL kinase domain G:C→A:T mutation and uracil DNA glycosylase abnormal expression in TKI-resistant acute lymphoblastic leukemia of Chinese population].

Most Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) patients often show rapid recurrence and development of ABL kinase domain (KD) mutation after tyrosine kinase inhibitor (TKI) treatment. To further investigate the mechanism of Ph(+) ALL fast relapse after TKI treatment, ABL KD mutation in 35 Chinese Ph(+) ALL with TKI resistance was detected by direct sequencing. The results showed that 77.1% (27/35) Ph(+) ALL patients with TKI resistance had ABL KD mutation and 55.6% (15/27) Ph(+) ALL patients with ABL KD mutation had T315I. Interestingly, 77.8% (21/27) Ph(+)ALL showed ABL mutation G: C→A:T, including T315I, E255K and E459K. Furthermore, all the Ph(+) ALL patients with two or more ABL KD mutations collaborated with complex chromosome abnormality and all the TKI-resistant Ph(+) ALL patients, whose karyotype progressed from simple t (9;22) into complex, developed ABL KD mutation. Moreover, the expression level of uracil-DNA glycosylase UNG2, which inhibits G:C→A:T transition in genomic DNA, decreased in Ph(+) ALL with TKI-resistance compared to that in newly diagnosis Ph(+) ALL. It is concluded that there is a high frequent ABL KD G:C→A:T mutation and a high genomic instability in Chinese TKI-resistant Ph(+) ALL. In addition, the decreased UNG2 expression in TKI-resistant Ph(+) ALL probably contributes to their high rate of ABL KD G:C→A:T mutation.

[Clinical and experimental characteristics of 20 patients with acute myeloid leukemia with complex variant of t(8; 21)].

This study was aimed to summarize and analyze the morphology, immunophenotype, cytogenetics, molecular biology (MICM), tyrosine kinase (TK) gene mutations and clinical features of acute myeloid leukemia (AML) with complex variant of t(8;21). A retrospective study was performed for 20 AML patients with complex variant of t(8;21) in our hospital from January 1994 to April 2012, including analysis of clinical feature, immunophenotype, chromosome karyotype, treatment regimen, as well as the overall survival (OS) and relapse-free survival (RFS). Mutations of C-KIT, FLT3-ITD, FLT3-TKD and JAK2V617F were detected by genomic DNA PCR and the sequencing was per-formed in 13 AML patients with complex variant of t(8;21). The results showed that (1) the incidence of 20 AML patients with complex variant of t(8; 21) was 2.4% of total t(8; 21) AML patients. In 20 AML patients with complex variant of t(8;21), 1 case was M1, 17 cases were M2, 2 cases were M4; 10 cases were myeloid phenotype and the other 3 were myeloid plus lymphoid phenotype. There were 16 kinds of cytogenetics additional involvement of chromosomal breakpoints: lp22, 1p32, 2q35, 2q14, 3p25, 5q13, 6p22, 7q21, llq11, 1lq13, 12q14, 12q24, 12p12, 14q32, 15p13, 20q12. (2) C-KIT aberrations were detected in 30.8% cases, all mutated in exon 17 (mutkit 17), only 1 case had JAK2V617F mutation. The result of FLT3 mutation screenings in AML patients with complex variant of t(8; 21) was negative. Of 5 patients with gene mutations, 1 patient (20%) achieved complete remission (CR), the median RFS and median OS time were 6.5 months and 8.9 months respectively. Of the 8 patients without gene mutations, 6 patietns (75%) achieved CR; the median RFS and median OS time were 26.6 months and 27.7 months respectively. It is concluded that the AML patients with complex variant of t(8;21) shows typical features of t(8;21) AML, but the existence of the tyrosine kinase-related gene mutation has important implications on remission rate and long-term survival of patients treated by induction chemotherapy.

[Clinical and cytogenetic study of 6 cases of hematological disorders associated with 20q- and t (20;21) (q11;q11) abnormalities].

OBJECTIVE: To analyze clinical and cytogenetic features of hematological disorders associated with 20q- and t (20;21) (q11;q11) abnormalities. METHODS: Following short-term culture of bone marrow cells, karyotypic analysis was carried out with R-banding. 20q- and t(20;21) (q11;q11) was detected by fluorescence in situ hybridization (FISH) using dual-color 20q11/12 probe, ST 20qter /ST 21qter probes, SE20(D20Z1)/SE 13/21 probes, and WC20/WC21 probes. RESULTS: Six (2.3%) of the 257 patients with 20q- detected by conventional karyotypic analysis were found to have t(20;21) (q11;q11) abnormality. Five cases had myelodysplastic syndrome, 1 had acute lymphoblastic leukemia. Above results were all confirmed by FISH. CONCLUSION: i (20q-), t(20;21) (q11;q11) seems to be a rare but recurrent chromosomal abnormality which is specifically associated with myeloid disease, late occurrence and poor prognosis. The translocation between chromosome 20q11 and 21q11 may form a novel fusion gene which has an important role in the pathogenesis of the disease.

[Immunophenotyping and molecular genetic analysis of diffuse large B-cell lymphoma].

OBJECTIVE: To perform immunophenotyping and molecular genetic analysis for diffuse large B-cell lymphoma (DLBCL), and to explore their correlation and implication for prognosis. METHODS: Immunohistochemical streptavidin peroxidase (SP) method was used to determine the expression of CD10, BCL6 and MUM1 in 59 cases of DLBCL. A Hans algorithm was used to classify DLBCL into germinal center B-cell (GCB) and non-GCB subtypes. Interphase fluorescence in situ hybridization (FISH) assay was performed on paraffin-embedded lymphoma tissue sections to detect translocations and amplifications of BCL6, BCL2 and MYC genes with dual-color break-apart BCL6 probe, dual-color dual-fusion IgH/ BCL2 probe and dual-color break-apart MYC probe, respectively. RESULTS: In the 59 cases of DLBCL, 28.8% (17/59) belonged to GCB subtype, and 71.2% (42/59) belonged to non-GCB subtype. The incidences of BCL6, BCL2 and MYC gene translocations were 24.1% (14/58), 1.7% (1/59) and 5.3% (3/57), respectively. The incidences of BCL6, BCL2 and MYC gene amplifications were 17.2% (10/58), 22.0% (13/59) and 21.1% (12/57), respectively. BCL6 amplification was not correlated with BCL6 translocation (P=0.424), but was correlated with amplifications of BCL2 and MYC (C=0.405 and 0.403, respectively, P <0.01). The incidence of BCL6 translocation in GCB type was higher than that in non-GCB type, and amplifications of BCL6, BCL2 or MYC were more frequently encountered in non-GCB type, though no statistical significance was detected (P=0.089 and 0.106, respectively). By univariate analysis, immunophenotyping and international prognostic index (IPI) exerted a significant effect on overall survival (OS) (P=0.047 and 0.001, respectively), but to which BCL6 translocation and amplification of the 3 genes were not related (P=0.150 and 0.444, respectively). By multivariate analysis, IPI score was the only independent prognostic factor for OS (RR =3.843, P=0.017). CONCLUSION: The GCB subtype of DLBCL is less common in the patient cohort. Common genetic aberrations have included BCL6 translocation and BCL6, BCL2 and MYC amplifications. Amplification of the 3 genes is strongly correlated with each other, and the incidence of BCL2 translocation is low. Immunophenotyping only has minor significance for the prognosis. Genetic aberrations cannot predict the clinical outcome of DLBCL.

[Clinical and laboratory investigation of pericentric inv(9)(p22q34) with the der(9)t(9;22)(q34;q11) in Ph-positive leukemia].

OBJECTIVE: To investigate clinical and molecule genetics features of four Ph-positive leukemia patients characterized by pericentric inv(9)(p22q34) with the der(9)t(9;22)(q34;q11). METHODS: Cytogenetic analysis was carried out on bone marrow directly or after short-period culture. R banding was used for karyotype analysis. BCR/ABL fusion gene was detected with interphase fluorescence in situ hybridization (FISH), and chromosome painting was carried out using specific probes. RT-PCR was used to detect BCR/ABL chimeric transcripts. RESULTS: One patient with acute myeloid leukemia (AML) presented three clones, which included one with a normal karyotype, one with t(9;22)(q34;q11), and one with inv(9)(p22q34) involving the der(9)t(9;22) and additional t(8;12)(q12;p11). The inv(9)(p22q34) has always co-occurred with der(9)t(9;22)(q34;q11) accompanied by der(22)t(9;22)(q34;q11) in all metaphases from the three patients with chronic myeloid leukemia (CML). B3a2 transcript was detected in all patients by RT-PCR. Inv(9)(p22q34) was found in both CML and AML, and was associated with poor prognosis. CONCLUSION: Inv(9)(p22q34) is a novel, rare, but recurrent secondary chromosomal abnormality for Ph-positive leukemia. Leukemia with der(9)t(9;22) and inv(9)(p22q34) has unique clinical and laboratory characteristics.

[Clinical and experimental studies of childhood acute myeloid leukemia with 11q23/MLL rearrangements].

OBJECTIVE: To explore clinical and experimental features of 28 cases of childhood acute myeloid leukemia (AML) with 11q23/MLL gene rearrangements. METHODS: Karyotypes of 234 cases of de novo childhood AML were analyzed using short-term culture of bone marrow cells and R-banding. The fusion transcripts involving MLL gene and partial tandem duplication of MLL (MLL-PTD) were detected by multiple reverse transcription polymerase chain reaction (RT-PCR) assay. Two cases with 11q23 translocation by karyotypic analysis but with negative result of multiple RT-PCR were studied with MLL-dual-color fluorescence in situ hybridization (D-FISH). RESULTS: R-banding karyotypic analysis has revealed 20 cases with 11q23 translocation (14 cases with M5, 4 cases with M4, 2 cases with M2), including 12 cases with t(9;11)(p22;q23), 3 cases with t(1;11)(q21;q23), 2 cases with t(6;11)(q27;q23), 1 case with t(11;19)(q23;p13), 1 with t(5;11)(q31;q23), and 1 with t(X;11)(q24;q23). Eighteen cases with 11q23 translocation having fusion transcripts involving MLL genes were confirmed with multiple RT-PCR; 2 cases showed negative results, but they were confirmed to have MLL rearrangements by D-FISH. MLL-PTD was also detected in 8 cases (4 cases M5, 2 cases M4, M2 and M6, one case each) from the other childhood AML cases. The total incidence of 11q23/MLL gene rearrangements was 11.97% (28/234), and most of patients(85.7%, 24/28) were M4/M5. The complete remission (CR) rate after treatment for the 28 cases with MLL rearrangements was 53.8%, the difference was significant by statistics (P< 0.05) compared with 90.5% for the control group (M4/M5 childhood AML with other karyotypic abnormalities or normal karyotype). Of them, 2 cases receiving intensive chemotherapy survived for 81 and 66 months, respectively, 4 cases receiving allogeneic stem cell transplantation survived for 21, 20, 16 and 11 months, respectively, and are still alive with CR. The medium survival (MS) time for 28 cases with 11q23/MLL rearrangements was 11 months, whereas the MS for control group was 15 months. The difference was not statistically significant(P> 0.05). CONCLUSION: The 11q23/MLL rearrangements is highly correlated with the occurrence of monocytic leukemia (M4 and M5). The 11q23 translocation and MLL-PTD are mutually exclusive, though both are indicative of poor prognosis. Intensive chemotherapy and allogeneic stem cell transplantation may ameliorate the clinical outcome. Multiple RT-PCR combined with karyotypic analysis and D-FISH are useful for screening the 11q23/MLL rearrangements in childhood AML.

[Clinical and laboratory features of pediatric acute myeloid leukemia with inversion of chromosome 16].

OBJECTIVE: To evaluate the clinical and laboratory features of pediatric inv(16) acute myeloid leukemia (AML) retrospectively. METHOD: Dual color fluorescence in situ hybridization (D-FISH) using a LSI CBFß inv(16) break apart probe labeled by Spectrum red and Spectrum green was performed in 15 acute myeloid leukemia cases, including 13 cases with or without abnormal eosinophils but with positive core binding factor ß (CBFß)-MYH11 fusion transcript detected by RT-PCR, and 2 cases with trisomy 8 (+8). The results were compared with the morphology, immunophenotype, karyotype and RT-PCR. RESULT: Morphologically, 12 cases were diagnosed as M(4)EO, 2 as M(4), and 1 as M(2a). Immunophenotypically, all 13 AML cases with inv(16) showed positive expression of CD(13) and CD(33), but without the expression of any lymphoid lineage antigens. Karyotyping analysis with G-banding detected inv(16) in 10 AML cases, including 9 M(4)EO cases and 1 M(2a), but only 5 positive cases were detected using R-banding technique. Among them, 2 cases had simultaneous +8 and trisomy22 (+22), one had +22 only in addition to inv(16). D-FISH revealed a CBFß-MYH11 rearrangement in 13 cases of AML with positive RT-PCR results, and the mean positive rate of cell detection was 55.15% (range 37.0% - 86.0%). The complete remission rate (CR) and median survival period in this series of inv(16) AML were 81.5%and 11 months, respectively, of whom, 8 cases were still in CR. Relapse and karyotypic evolution were seen in case 5 with +8, +22 in addition to inv(16). CONCLUSION: AML with inv(16) is a special subtype. Most cases belong to M(4)EO. Its prognosis is good in general, but it seems to be an unfavorable feature for AML with inv(16) and +8, +22 simultaneously, especially with karyotypic evolution. For detection of inv(16), G-banding technique is evidently superior to R-banding technique. D-FISH combined with RT-PCR are more sensitive and reliable than chromosome banding analysis.

[Expression of SET-NUP214 fusion gene in patients with T-cell acute lymphoblastic leukemia and its clinical significance].

This study was aimed to investigate the occurrence and clinical significance of the SET-NUP214 fusion gene in patients with T-cell acute lymphoblastic leukemia (T-ALL), analyse clinical and biological characteristics in this disease. RT-PCR was used to detect the expression of SET-NUP214 fusion gene in 58 T-ALL cases. Interphase FISH and Array-CGH were used to detect the deletion of 9q34. Direct sequencing was applied to detect mutations of PHF6 and NOTCH1. The results showed that 6 out of 58 T-ALL cases (10.3%) were detected to have the SET-NUP214 fusion gene by RT-PCR. Besides T-lineage antigens, expression of CD13 and(or) CD33 were detected in all the 6 cases. Deletions of 9q34 were detected in 4 out of the 6 patients by FISH. Array-CGH results of 3 SET-NUP214 positive T-ALL patients confirmed that this fusion gene was resulted from a cryptic deletion of 9q34.11q34.13. PHF6 and NOTCH1 gene mutations were found in 4 and 5 out of 6 SET-NUP214 positive T-ALL patients, respectively. It is concluded that SET-NUP214 fusion gene is often resulted from del(9)(q34). PHF6 and NOTCH1 mutations may be potential leukemogenic event in SET-NUP214 fusion gene.

p210 BCR/ABL1 as a secondary change in a patient with acute myelomonocytic leukemia (M4Eo) with inv(16).

t(9;22) as a secondary change of inv(16) is a rare chromosome aberration in de novo acute myeloid leukemia (AML). Here, we report the case of a 31-year-old man with this rare abnormality. Karyotypic analysis showed a complex chromosome aberration:46,XY,der(8)t(8;10)(p23;q25),der(10)t(8;10)t(10;16)(p13;q22),der(16)inv(16)(p13q22)t(10;16)[4] and 46,XY,idem,t(9;22)(q34;q11)[6]. Fluorescence in situ hybridization detected both the CBFB and the BCR/ABL1 rearrangements. CBFB/MYH11 (A type) and BCR/ABL1 (b3a2) fusion transcripts were both detected by real-time quantitative RT-PCR. The patient was treated with standard AML chemotherapy and autologous peripheral blood stem cell transplantation. He also received imatinib (400 mg/day) during the chemotherapy intervals and after transplantation. Molecular remission was achieved at the beginning of the third chemotherapy and he remained in remission until the last follow-up (22 months after diagnosis). To our knowledge, this is the first reported case of de novo AML in which has p210(BCR/ABL1) occurred as a secondary change of inv(16).

Prognostic power of abnormal cytogenetics for multiple myeloma: a multicenter study in China.

BACKGROUND: Chromosomal abnormalities have been shown to play an important prognostic role in multiple myeloma (MM). Interphase fluorescence in situ hybridization (i-FISH) has been much more effective to identify cytogenetic aberrations in MM than conventional cytogenetic technique (CC). To clearly determine the cytogenetic features of Chinese MM patients and identify their prognostic implications, we designed a multicenter study based on i-FISH including 672 patients from 52 hospitals in China. METHODS: All 672 patients were systematically screened for the following genomic aberrations: del(13q), IgH rearrangement, del(p53) and 1q21 amplifications. RESULTS: The analysis showed that the chromosomal changes were detected in 22.1% patients by CC and in 82.3% patients by i-FISH. The most common abnormalities by CC were chromosome 1 aberrations (48.4%), -13/13q- (37.6%), hyperdiploidy (36.6%), hypodiploidy (30.1%) and IgH rearrangements (23.7%). The most frequent abnormalities by FISH was del(13q), which was found in 60.4% patients, whereas IgH rearrangement, 1q21 amplification and p53 deletions were detected in 57.6%, 49.0% and 34.7% cases, respectively. By statistical analysis, -13/13q- by CC was associated with low level of platelet (P = 0.015), hyperdiploidy was associated with low level of serum albumin (P = 0.028), and IgH rearrangement by FISH was associated with high level of ß2 microglobulin (P = 0.019). Moreover, 1q21 amplification and del(p53) by FISH conferred a high incidence of progressive disease (PD) after initial therapy. Metaphase detection of IgH rearrangements and chromosome 1 aberrations concurrently was associated with a short progression free survival (PFS) (P = 0.036). No significant prognostic implications of other cytogenetic abnormalities were found associated with overall survival and PFS. CONCLUSIONS: Chinese MM patients had similar cytogenetic abnormalities compared with the previous reported studies. However, the prognostic significance of FISH aberrations were not clearly determined and further study is required.

[Clinical and experimental study of a multiple myeloma case with low hypodiploidy].

OBJECTIVE: To report the clinical and laboratory characterization of a case of multiple myeloma with low hypodiploid complex karyotyptic abnormalities. METHODS: Cytogenetic examination of bone marrow performed by 24 h culture method. R-banding technique was used to analyze the karyotype. Interphase fluorescence in situ hybridization (FISH) was performed using chromosome probes such as 13q14, p53, Rb1, 1q21 and IgH/CCND1. The DNA content was detected by flow cytometry. RESULTS: Chromosome analysis revealed complex chromosomal rearrangement. Five cells had a low hypodiploid karyotype with 35 chromosomes. Three cells had the duplication of the low hypodiploid karyotype. Four cells had a normal karyotype. Monosomy 1, 13, 14, 17 and a mark chromosome 1 derived from chromosome 11 resulting in the amplication of CCND1 gene were confirmed by interphase FISH. Flow cytometric analysis displayed a low hypodiploid peak with the DNA index of 0.8426. CONCLUSION: These results indicated that the low hypodiploidy is a rare abnormality in multiple myeloma. Interphase FISH is a reliable method for detecting molecular abnormalities in multiple myeloma.

[Clinical and molecular cytogenetic studies of a case of B-lineage acute lymphoblastic leukemia with t(14;14)(q11;q32)].

OBJECTIVE: To report on a rare case of B-lineage acute lymphoblastic leukemia (B-ALL) with t(14;14) (q11;q32) and clarify its clinical and molecular cytogenetic features. METHODS: Clinical data of a B-ALL patient with t(14;14) (q11;q32) were analyzed. After 24 hour of unstimulated culturing, chromosome specimens of bone marrow cells were prepared with regular method, and R-banding was used for karyotype analysis. Fluorescence in situ hybridization (FISH) analysis was performed on fixed bone marrow cells using IGH dual-color break-apart probe, CEBPE dual-color break-apart probe, whole chromosome paint (WCP) probe for chromosome 4, and Chromoprobe Multiprobe-ALL System probe. RESULTS: The 39-year-old female was diagnosed with B-ALL based on morphologic and immunophenotypic analyses. Conventional cytogenetic analysis showed a karyotype of 47, XX, +4, t(14;14) (q11;q32) [20], which was confirmed by FISH analysis. FISH using IGH-dual-color break-apart probe confirmed involvement of IGH gene in t(14;14) (q11;q32), and FISH using CEBPE dual-color break-apart probe indicated that CEBPE is the partner gene involved in t(14;14) (q11; q32). The patient achieved complete remission (CR) after a round of combined chemotherapy. At the time of follow-up, she had remained CR for more than 6 months. CONCLUSION: t(14;14) (q11;q32) simultaneously involving IGH and CEBPE genes in B-ALL is a rare but recurrent genetic abnormality that may identify a new subgroup of B-ALL. In B-ALL patients, t(14; 14) (q11; q32) involving IGH/CEBPE translocation may indicate a better prognosis.

[Fluorescence in situ hybridization study of acute myeloid leukemia with cryptic chromosome rearrangements].

OBJECTIVE: To detect specific chromosome rearrangements in acute myeloid leukemia (AML) using interphase-fluorescence in situ hybridization (FISH). METHODS: All cases were studied by R-band karyotypic analysis using direct method and/or short-term culture for chromosomes preparation. Interphase-FISH was performed in 108 cases of AML with M5, M4, M2, M3 subtypes including 103 cases with normal karyotypes, 4 cases with chromosomal abnormalities other than specific chromosomal rearrangements using chromosome translocation probe such as AML1/ETO, PML/RARα, CBFß/MYH11 and MLL. RESULTS: Of 38 cases of M2-AML without t(8;21) on conventional cytogenetics(CC) analysis, 4 cases showed positivity for AML1/ETO fusion transcript, which included 2 cases with typical signal model and 2 with insertion. Of 9 cases of M3-AML without t(15;17) on CC analysis, 6 showed positivity for PML/RARα fusion transcript including 2 with typical signal model, 3 with insertion, one without PML/RARα rearrangement on reverse transcription-PCR and FISH assay using PML/RARα probe. FISH assay using the RARα dual color, break-apart rearrangement probe indicated a partial deletion of RARα. Of 23 cases with M4 or M4EO-AML without inv(16) on CC analysis, 3 showed positivity for CBFß/MYH11 fusion transcript. Of 38 cases without 11q23 translocation on CC analysis, all cases were negative for MLL rearrangement. CONCLUSION: Interphase-FISH can detect specific chromosome rearrangements such as AML1/ETO, PML/RARα or CBFß/MYH11 in some AML cases with normal karyotype, though it seemed less useful for the detection of MLL rearrangement.

[Report of ten cases of hematologic malignancies with idic(20q-) and literature review].

OBJECTIVE: To analyze the clinical and molecular cytogenetic features of hematologic malignancies with idic(20q-). METHODS: The clinical data of 10 patients with idic (20q-) were analyzed. Karyotyping analysis was carried out with R banding technique. A CEP20 probe was used to perform single-color fluorescence in situ hybridization (FISH). A subtelomeric probe for 20q and a locus-specific probe for 20q12 were used to perform dual-color FISH. The literatures of hematologic malignancies with idic(20q-) were reviewed. RESULTS: Of the 10 cases, 2 were diagnosed as acute erythroid leukemia, 1 primary myelofibrosis, 3 myelodysplastic syndromes (MDS) and 4 highly suspected (HS-MDS). Karyotype analysis showed that one of the normal chromosome 20 allele was substituted by one or two metacentric isochromosomes smaller than the normal one in all 10 cases. It was confirmed to be der(20)del(20)(q11q13)idic(20)(p11), i.e., idic(20q-) by FISH assay. Partial cells in 2 of the 10 cases had 20q- as the sole karyotypic anomaly. CONCLUSION: Idic(20q-) results from a pre-existing del(20q) and is strongly associated with MDS and acute erythroid leukemia. Idic(20q-) as a recurrent cytogenetic abnormality is helpful for diagnosing HS-MDS in patients with cytopenia but only slight or absent dysplasia.

[The different signal patterns of two FISH probes in the FISH detection of Ph-positive leukemia and their clinical significance].

OBJECTIVE: To compare the signal patterns of dual color extra-signal BCR/ABL probe (ES-FISH) and dual color dual fusion BCR/ABL probe (D-FISH) in the fluorescence in situ hybridization (FISH) detection of Ph-positive leukemia, and to explore their diagnostic value. METHODS: ES-FISH probe and D-FISH probe were used, respectively, to detect the BCR/ABL fusion gene in 74 cases with typical t(9;22)(q34;q11) and 37 cases with variant t(9;22)(q34;q11) translocation or complex karyotypic abnormalities containing Ph translocation. RESULTS: The BCR/ABL fusion gene in all cases with typical t(9;22)(q34;q11) could be detected by both FISH probes. D-FISH had a signal pattern of 1O1G2F, while ES-FISH showed a signal pattern of 2O1G1F. ES-FISH enables the minor breakpoint cluster region to be identified in 9 cases (12.2% ) of Ph-positive leukemia, whereas D-FISH could not differentiate the minor breakpoint cluster region from major breakpoint cluster region. D-FISH could distinguish simple ABL gene deletion from simultaneous deletion of the ABL and BCR genes in 8 cases (10.8%) of Ph-positive leukemia patients, but ES-FISH could not. For variant Ph translocation or complex karyotypic abnormalities containing Ph translocation, each FISH probe showed four or six types of signal pattern, most of which were atypical. The exact interpretation was dependent on conventional karyotypic analysis and FISH on metaphases. CONCLUSION: ES-FISH and D-FISH probes displayed different signal patterns in Ph-positive leukemia due to their differences in size and covered regions. ES-FISH and D-FISH probes may be selected as better probe for Ph-positive acute lymphocytic leukemia and Ph-positive chronic myeloid leukemia, respectively. When imatinib was used for treatment, there was no preference between ES-FISH and D-FISH probe, because major breakpoint cluster region, minor breakpoint cluster region and partial sequence deletion of derivative chromosome 9, would not affect the prognosis of Ph-positive leukemia. However, considering that ES-FISH probe has a better cost-performance than D-FISH probe does, it is recommended as first choice.

[A clinical and laboratory study of TCF3-PBX1 positive adult acute lymphoblastic leukemia.].

OBJECTIVE: To explore the morphology, immunophenotype, cytogenetics and clinical features of TCF3-PBX1 fusion gene positive adult acute lymphoblastic leukemia (ALL). METHODS: R banding was used to analyze conventional cytogenetics (CC), interphase fluorescence in situ hybridization (iFISH) and RT-PCR to detect the TCF3-PBX1 fusion gene, and flow cytometry to immunophenotype. The clinical and laboratory features and long-term follow-up of the patients were analyzed. RESULTS: The incidence of 19 TCF3-PBX1-positive adult ALL was 3.13% of total ALL patients. Of them, 12 and 7 cases were diagnosed as L(1) and L(2) morphology respectively; 7 cases with balanced translocation of chromosome 1 and 19; 10 with der(19) t(1;19) formed from unbalanced translocation and 2 with normal karyotypes. TCF3-PBX1 fusion gene was detected by RT-PCR in 9 cases, and by iFISH in 17. 16 cases were B-phenotype and the other 2 T-phenotype; 17 cases had lymph node, spleen or liver infiltration. Of 18 patients received chemotherapy, 17 (94.7%) achieved complete remission (CR); the median relapse-free survival (RFS) and median overall survival was 3.2 months and 7.2 months, respectively. CONCLUSIONS: TCF3-PBX1-positive adult ALL had unique clinical and pathological features with high remission rate, high relapse rate and short survival time and should be considered to receive intensified treatment strategies. iFISH combined with CC and RT-PCR can increase the detection rate of t(1;19)/TCF3-PBX1 fusion gene.

[Detection and clinical significance of JAK2 mutation in 412 patients with chronic myeloproliferative neoplasms].

OBJECTIVE: To investigate the frequency of JAK2V617F mutation in Chinese patients with chronic myeloproliferative neoplasms (MPN) and to study the relationship between JAK2V617F mutation and clinical characteristics. METHODS: JAK2V617F mutation was screened by allele-specific polymerase chain reaction (AS-PCR). RESULTS: JAK2V617F mutation was detected in 277 of the 412 patients with MPN. The frequency of JAK2V617F mutation was similar among essential thrombocythemia (ET), idiopathic myelofibrosis (IMF) and chronic myeloproliferative disorders-unclassified (MPD-U) (P > 0.05), but it was significantly lower than that in polycythemia vera (PV) (P < 0.05). The presence of JAK2V617F was found to be significantly correlative with advanced age at diagnosis (P < 0.01) and with higher hemoglobin levels and higher leukocyte counts (P < 0.05). Significant difference was found in complication of vascular events between JAK2V617 positive and negative patients (P < 0.05). JAK2V617F positive MPD-U patients were more prone to progress into typical MPN compared with JAK2V617F negative MPD-U patients. The association between abnormal karyotype and JAK2V617F was not found in cytogenetical analysis of 301 patients. CONCLUSION: The presence of JAK2V617F in MPD-U is associated with the disease development. There is a correlation between JAK2V617F mutation in MPN and advanced age, higher leukocyte counts, hemoglobin level and vascular events.

[Establishment and characterization of a new human myeloid leukemia cell line SH-2].

OBJECTIVE: To establish and characterize a novel human myeloid leukemia cell line SH-2. METHODS: Bone marrow mononuclear cells (BMMNC) isolated from a AML-M2 patient, who failed to obtain complete remission after chemotherapy and allogenic bone marrow transplantation were passed in a long term IMDM culture medium supplemented with 20% fetal calf serum. Stromal cells were retained and rh-IL-3 was added in the culture system. A new human myeloid leukemia cell line SH-2 was successfully established with a cytogenetic characteristics of a loss of Y chromosome (-Y), a derivative chromosome 16 resulting from unbalanced translocation between chromosome 16 and 17, monosome 17, trisomy 19 and p53 alteration. Various methods were employed to characterize SH-2 cell line. RESULTS: SH-2 cells has been maintained without cytokine and stromal cells for more than 3 years without EB virus and mycoplasma contamination. SH-2 cells had the basically same morphological, immunophenotypic and cytogenetic features as the patient's leukemia cells did, such as myeloid morphology, an immunophenotype of CD13+, CD33+, CD56+, CD16/56+ and a hypodiploid karyotype of 45, X, -Y, der(16)t(16;17)(q24;ql2), -17, +19, which were gradually decreased and replaced by the near-tetraploid cells with a karyotype of 73-102(80), XX, -Y, -Y, del (q131)x2, der(16)t(16;17)(q24;q12)x2, -17, -17, +19, +19. FISH and multiple FISH delineated all the abnormalities and revealed a loss of one p53 allele due to monosomy 17. DNA direct sequencing detected a point mutation of CAG to CAT at codon 576 of exon 5 in another p53 allele. RT-PCR showed that SH-2 cells expressed apoptosis-related genes (bcl-2, Fas, GST-pi and p2) rather than MDR-related genes. Short tandem repeat PCR provided powerful evidence for the derivation of SH-2 cell line from the patient's leukemia cells. SH-2 cells had certain colony formation and tumorigenic capacities in nude and SCID mice. CONCLUSION: SH-2 is a new myeloid leukemia cell line with a unique biology background, and will provide a useful tool for leukemia research.

[Detection of JAK2V617F mutation and its clinical significance in 80 patients with M2 acute myelogenous leukemia].

OBJECTIVE: To explore the prevalence and prognostic significance of JAK2V617F gene mutation in acute myelogenous leukemia M2 (AML-M2) patients. METHODS: Allele specific polymerase chain reaction (PCR) was used to detect JAK2 gene mutation. RESULTS: Of 80 de novo AML-M2 patients, 6 at the time of first diagnosis and 1 at relapse were found to have JAK2V617F gene mutation (8.8%, 7/80). Morphologically, the whole blood and bone marrow of the 7 AML-M2 patients with JAK2V617F gene mutation presented a picture of acute leukemia instead of myeloproliferative disorders. Immunophenotypically, bone marrow samples showed myelogenous linage expression. Complete remission was obtained in 4 of 5 AML-M2 patients with JAK2V617F mutation who received treatment, while one patient had no response to the treatment. Follow-up was performed in all the 5 patients, with a median survival of 18.5 months in 4 patients. CONCLUSION: JAK2V617F gene mutation, as a type-1 mutation, might not be an initial event in the pathogenesis of acute myelogenous leukemia, and its presentation does not mean a poor prognosis in de novo AML patients.