Mutation and expression of PAX5 gene in adult acute lymphoblastic leukemia / 中国实验血液学杂志

PAX5 is an important transcription factor of paired-box(PAX) family. The aim of this study was to investigate the mutations and expression of PAX5 and its clinical significance in adult patients with acute lymphoblastic leukemia (ALL). Reverse transcription polymerase chain reaction (RT-PCR) and genomic PCR were performed to detect the deletions of PAX5 and point mutations of PAX5 exon 2-10 in 101 cases of adult ALL and were confirmed by cloning and sequencing. In addition, quantitative PCR (qPCR) was performed to evaluate the expression of PAX5. Furthermore, the correlations of mutations and expression of PAX5 with clinical parameters were analyzed, and the prognostic significance was evaluated as well. The results showed that PAX5 mutations were observed in 8 of 101 (7.9%) patients with B-ALL. A total of 9 types of mutations were detected, including 4 types of deletions, 4 types of point mutations and 1 insertion mutation; percentage of patients with age ≥ 50 years was higher in PAX5 mutation group than in wide-type group (62.5% vs 21.5%,P = 0.031) . The statistical differences were observed in B-cell subtype, initial platelet count and immunophenotypes between high and low expression of PAX5 (P < 0.05) . In addition, patients with high expression of PAX5 had higher first complete remission rate (86.7% vs 62.5%, P = 0.030) and 6-month overall survival rate (75.0% vs 50.0%, P = 0.034) compared with patients with low expression of PAX5. It is concluded that deletion/insertion/point mutations and aberrant expression of PAX5 can be observed in adult patients with B-ALL. Mutations and aberrant expression of PAX5 correlated with clinical parameters and have important clinical significance.

Genetic characteristics and its prognostic significance for 217 adult patients with acute lymphoblastic leukemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To evaluate cyto- and molecular genetic characteristics of adult patients with acute lymphoblastic leukemia (ALL) and its prognostic significance.</p><p><b>METHODS</b>Two hundred and seventeen adult patients with ALL were analyzed for cyto- and molecular genetic characteristics with combined conventional cytogenetics, fluorescence in situ hybridization (FISH), real-time quantitative PCR (qPCR) and nested PCR. Significance of genetic findings for prognosis was evaluated.</p><p><b>RESULTS</b>t(9;22)(q34;q11)/BCR-ABL has been the most frequent abnormality found in the cohort (56.3%). And 22.4% of cases with BCR-ABL detected by FISH was negative by cytogenetic analysis. Ratio of patients in high-risk group increased with age; Patients with B-ALL had a higher risk group than the average-risk group (98.40% vs. 65.70%, P=0.000). The overall survival (OS) rates at 3-month (67.30% vs. 85.10%, P=0.042), 6-month (55.1% vs. 80.4%, P=0.008), 12-month (34.0% vs. 59.1%, P=0.017) and 24-month (13.0% vs. 36.6%, P=0.010) were lower in high-risk group than in average-risk group, with medium OS time (11 months, 95% CI 8.0-13.9) being significantly shorter compared with the average-risk group (19 months, 95%CI 10.8-27.1).</p><p><b>CONCLUSION</b>Adult patients with ALL have unique cyto- and molecular genetic characteristics, which has important value for prognosis and guiding treatment. Moreover, combined cytogenetic and molecular genetic techniques can precisely define sub-groups of ALL patients.</p>

Characteristics of 4 specific target antigens in adult acute lymphoblastic leukemia / 中国实验血液学杂志

This study was aimed to investigate clinical and prognostic significances of 4 target antigens (CD19, CD20, CD22 and CD33) for antibody-based immunotherapy and to evaluate the applications of these antibody-based target therapy to adult acute lymphoblastic leukemia (ALL). The immunophenotype of 220 adult patients with ALL were analyzed by four-color flow Cytometry, and cytogenetic and molecular parameters were detected by conventional cytogenetics, fluorescence in situ hybridization, real-time quantitative PCR, nested PCR and DNA sequencing. The results showed that CD19 positive (CD19(+)) cases were more in female (46.4% vs. 23.4%, P = 0.006), elderly patients aged > 60 years (14.4% vs. 2.1%, P = 0.022), CD33(+) co-expression cases (47.8% vs. 12.0%, P = 0.001) and genetic high-risk group (55.8% vs. 20.8%, P = 0.002) compared with CD19 negative (CD19(-)) cases; CD20(+) cases had lower co-expression of CD13 than CD20(-) cases (31.6% vs.67.1%, P = 0.000) and no significant prognostic indications for CD20(+) was observed; CD22(+) cases had higher relapse rate at 12-month than CD22(-) cases (93.9% vs.57.1%, P = 0.041) in B-ALL patients; CD33(+) cases had higher incidence of Ph(+) than CD33(-) cases (43.5% vs.19.4%, P = 0.007) and significantly correlated with Ph(+) (r = 0.261, P = 0.006). It is concluded that elucidation of the characteristics of the target antigens (CD19, CD20, CD22, CD33) used for antibody-based immunotherapy will help hematologists making the correct decision whether and when to use these antibody-based target therapies.

Characteristics of NOTCH1 mutation in adult T-cell acute lymphoblastic leukemia / 中国实验血液学杂志

This study was aimed to investigate the characteristics and clinical significance of NOTCH1 mutation in adult T-cell acute lymphoblastic leukemia (T-ALL). Exon 26/N-terminal region of the heterodimerization domain (HD-N) , exon 27/ C-terminal region of the heterodimerization domain (HD-C) , exon 28 and exon 34/ proline-glutamic acid-serine-threonine (PEST) domain of the NOTCH1 gene were amplified, cloned and sequenced in 42 adult patients with T-ALL to identify the frequency, position and type of NOTCH1 mutation, their correlations with laboratorial and clinical parameters, as well as their relevant prognostic significance. The results showed that the frequency of NOTCH1 mutation in this cohort of adult patients was 66.7% (28/42); A total of 45 types of NOTCH1 mutations were identified in present study, most of them were in HD-N (48.9%, 22/45) and PEST (40.0%, 18/45) domains. Mutation in amino acid 1575 (L1575P) was the top one type of mutation in HD-N (25.0%, 7/28), and amino acid 2443 was the most common mutation position in PEST domain (14.3%, 4/28). In newly diagnosed patients, white blood cell (WBC) >10×10(9)/L and blasts in bone marrow > 50% were predominant in patients with NOTCH1 mutation (91.7% vs 54.5%, P = 0.021 and 95.8% vs 57.1%, P = 0.006 respectively). Immunophenotyping analysis indicated that patients with CD10 positive were more in NOTCH1 mutation group than wild-type group (51.9% vs 0%, P = 0.006), whereas patients with CD15 and CD11b positive were less in NOTCH1 mutation group (5.3% vs 42.9%, P = 0.047 and 0% vs 57.1%, P = 0.002 respectively). It is concluded that NOTCH1 mutation in adult T-ALL has different characteristics and clinical significance from pediatric patients, and the difference between Chinese patients and patients in Western countries is also indicated.

Expression characteristics of isoforms of Ikaros and Helios in patients with leukemia and their mechanism / 中国实验血液学杂志

This study was aimed to investigate the expression characteristics of two transcriptional factors in Ikaros family, Ikaros and Helios isoforms and their mechanism, as well as their correlation with clinical parameters, which play important roles in transcriptional regulation of hematopoiesis. Expression of Ikaros and Helios isoforms in a total of 163 patients with leukemia and correlations between Ikaros and Helios isoforms were analyzed by PCR. The results showed that different expression patters of Ikaros and Helios isoforms existed in leukemia patients, that is, Ikaros isoform (Ik-6) was predominantly expressed in acute lymphoblastic leukemia (ALL) with BCR/ABL fusion gene, while Helios isoform (He-i) was overexpressed in T-cell ALL patients. The results of cloning and sequencing demonstrated that the isoforms of Ikaros and Helios had different genetic alterations. The statistical correlation between these two isoforms not was found in this study, although interaction between Ikaros and Helios has been reported. It is concluded that although Ikaros and Helios belong to the same family with similar structure of zinc fingers, their isoforms have different expression profile, specific genetic alterations, and different clinical relevance in patients with leukemia. The connection and interaction between Ik-6 and He-i needs further research.

Detection and clinical features of MLL gene rearrangement in adult patients with acute leukemia / 中国实验血液学杂志

This study was purposed to investigate the incidence of mixed lineage leukemia (MLL) gene rearrangement and partner gene types as well as the clinical features and prognosis of acute leukemia (AL) with this rearrangement through detection in adult AL using combination of 3 techniques, and to evaluate the clinical value of this combination detection. The MLL gene rearrangement in 183 cases of adult AL was detected by combination of conventional cytogenetics, split signal FISH and multiplex nested PCR. The results showed that the incidence of MLL rearrangements in adult patients with AL was low (8.2%), and MLL-AF4 fusion gene was most common and predominant in acute lymphoblastic leukemia (ALL), while the MLL-AF6 and MLL-AF9 were most frequent in acute myeloid leukemia (AML). Extramedullary involvements were found in 40% of MLL-rearranged AL patients, and 33.3% of patients with MLL-rearranged AL reached to complete remission within 30 days during induction chemotherapy. In addition, in this cohort of MLL-rearranged adult AL patients, the 3-month relapse rate and 6-month overall survival rate were 50.0% and 50.0% respectively. It is concluded that the rate of missed diagnosis of CC technique for patients with MLL-rearranged AL reached to 60% in this study, while the combination of CC, FISH and multiplex nested PCR has been confirmed to have important significance for evaluating prognosis and conducting clinical therapy of patients with MLL-rearranged AL.