[The Factors Affecting Relapse in Pediatric B-cell Acute Lymphoblastic Leukemia Patients without Prognostic Fusion Genes Following Up for 10 years].

OBJECTIVE: To analyze the efficacy of children with B-cell acute lymphoblastic leukemia (B-ALL) without prognostic fusion genes treated by CCLG-ALL 2008, and investigate the related factors affecting the recurrence of the patients. METHODS: B-ALL patients without prognostic fusion genes treated by the protocol of CCLG-ALL 2008 in our hospital from March 2008 to December 2012 were retrospectively analyzed. Follow-up time was ended in August 31, 2019. The median follow-up time was 92 months (range 0-136 months). Kaplan-Meier was used to detect the RFS, and COX multivariate regression analysis was employed to identify the independent factors affecting the recurrence of the patients. RESULTS: There were 140 males and 99 females enrolled in this study. The ratio of male to female was 1.41∶1. The median age was 4.4 years old and the median number of WBC at initial stage was 4.98×109/L. There were 77 cases relapsed during the observation while 162 without relapsed, 16 cases lost to follow-up and 72 cases died. The recurrence and mortality rate was 32.22% and 30.1%, respectively, in which 45 cases died of recurrence (62.5% of the total deaths). Univariate analysis showed that the age≥6 years old, WBC >100×109/L, the bone marrow blasts on day 15≥25%, the bone marrow minimal residual disease (MRD) at week 12 >10-4, and the higher risk were the main factors affecting the recurrence of the patients (P<0.05). Multivariate COX regression analysis showed that age≥6 years old, WBC >100×109/L, bone marrow MRD >10-4 at the 12th week were the independent risk factors affecting recurrence of the patients. CONCLUSION: Age, initial WBC, and bone marrow MRD at the 12th week were correlated with recurrence in children with B-ALL without prognostic fusion genes, which can be used as prognostic indices of recurrence risk in clinical.

[Expression and Clinical Significance of Long Non-coding RNA AC002454.1 in Children with Acute Leukemia].

OBJECTIVE: To study the difference of long non coding RNA (lncRNA) expression profile in bone marrow specimens of children with acute leukemia (AL) and other hematological disease children with normal bone marrows as controls, to screen the lncRNA related with childhood hematological diseases, and to explore the expression of lncRNA AC002454.1 and its clinical significance in AL children. METHODS: The microarray gene chip technology was used to statistically analyze the lncRNA in bone marrow cells of newly diagnose AL children and control children. Ninty-seren differentially expressed lncRNAs were selected. The bone marrow specimens of ALL children (21 cases), AML children (22 cases) and control children (21 cases) were verified and compared by using qRT-PCR; then the lncRNA with maximum differential expression-lncRNA AC002454.1 was selected and used to analyze the relation of relative expression level with clinical indicators. RESULTS: The microarray gene chip detection showed that 1 884 differentially expressed lncRNA were found in ALL children, and 4 289 differentically expressed lncRNA were found in AML children. The results confirming these differentically expressed lncRNA by qRT-PCR showed that 9 lncRNA expression were significantly up-regulated in ALL children, and 12 lncRNA expression were significantly up-regulated in AML children. Among these up-regulated lncRNA, the difference of AC002454.1 expression was most significant in ALL and AML children (P＜0.05, P＜0.01). The detection showed that there was a significant difference, in AC002454.1 relative expression level of newly diagnosed T-ALL and B-ALL children (P＜0.01), moreover, this difference also was found in ALL and AML children (P＜0.05). The detection analysis showed that there was no statistical difference in AC002454.1 relative expression level among the different sex, age, WBC count at initial diagnosis, chromosome, fusion gene, and risk stratification (P＞0.05 for all). CONCLUSION: The lncRNA expression profile of AL children has been gained by using the lncRNA microarray gene chip technicology. AC002454.1 the significantly high expression exist in AL children, which relates with immunotyping and prognosis of AL children in a certain degree.

[Safety and Efficacy of VDMP Re-induction Regimen in Chinese Children with Relapsed Acute Lymphoblastic Leukemia-A Report from Jiangsu Childhood Hematology Group].

OBJECTIVE: To evaluate the therapeutic safety and efficacy of VDMP re-induction regimen in Chinese children with relapsed acute lymphoblastic leukemia (ALL). METHODS: Forty-one patients with relapsed ALL were prospectively enrolled in this study. All the patients were distributed in 3 children's hospitals and treated with VDMP regimen as the first re-induction chemotherapy. Therapeutic efficacy and side-effects were analyzed. RESULTS: The ratio of male to female was 27:14. The median age was 7.9 (2.2-15.4) years old. Patients relapsed at very early, early, and late stage were 7 cases, 11 cases, and 23 cases, respectively.The immunophenotype analysis showed that 38 cases were B-ALL, and 3 cases were T-ALL. All patients suffered from grade 4 of neutropenia and forty(97.6%) cases got infection, of them one case died. Thirty-nine(95.1%) cases had nonhematologic adverse event at least one organ involved grade 3 in 38 out of 41 cases, the VDMP therapy was completed, 34(89.5%) cases achieved a complete remission (CR), 1 case achieved partial remission(PR), and 3 cases didn't get remission. Follow-up data of 38 cases with completing VDMP chemotherapy were obtained, only one case was lost. Among 37 cases available for evaluation, 16 cases received allo-hematopoietic stem cell transplantation(allo-HSCT) after chemotherapy, and 13 patients survived, while 21 cases did not receive allo-HSCT(treated with chemotherapy only), and 8 patients survived.The overall survival rate of allo-HSCT group was significantly higher than that of those treated with chemotherapy only(P<0.05). CONCLUSION: VDMP re-induction regimen is effective and well tolerable for pafients in the treated children with relapsed ALL. After remission, allo-HSCT is recommended with the aim of long survival.

Outcome of children with newly diagnosed acute lymphoblastic leukemia treated with CCLG-ALL 2008: The first nation-wide prospective multicenter study in China.

Acute lymphoblastic leukemia (ALL) is the most common malignancy among children. The trial Chinese Children Leukemia Group (CCLG)-ALL 2008 was a prospective clinical trial designed to improve treatment outcome of childhood ALL through the first nation-wide collaborative study in China. Totally 2231 patients were recruited from ten tertiary hospitals in eight cities. The patients were stratified according to clinical-biological characteristics and early treatment response. Standard risk (SR) and intermediate risk (IR) groups were treated with a modified BFM based protocol, and there was 25%-50% dose reduction during intensification phases in the SR group. Patients in high risk (HR) group received a more intensive maintenance treatment. Minimal residual disease (MRD) monitoring with treatment adjustment was performed in two hospitals (the MRD group). Complete remission (CR) was achieved in 2100 patients (94.1%). At five years, the estimate for overall survival (OS) and event-free survival (EFS) of the whole group was 85.3% and 79.9%, respectively. The cumulative incidence of relapse (CIR) was 15.3% at five years. The OS, EFS and CIR for the SR group were 91.5%, 87.9%, and 9.7%, respectively. The outcome of the MRD group is better than the non-MRD group (5y-EFS: 82.4% vs 78.3%, P = .038; 5y-CIR: 10.7% vs 18.0%, P < .001). Our results demonstrated that the large-scale multicenter trial for pediatric ALL was feasible in China. Dose reduction in the SR group could achieve high EFS. MRD-based risk stratification might improve the treatment outcome for childhood ALL.

Gene polymorphisms in the folate metabolic pathway and risk of pediatric acute lymphoblastic leukemia: a case-control study in a Chinese population.

Polymorphisms in folate pathway genes may influence susceptibility to pediatric acute lymphoblastic leukemia (ALL). This case-control study was undertaken to analyze the association of genetic polymorphisms (677C>T and 1298A>C) of methylenetetrahydrofolate reductase (MTHFR) and reduced folate carrier (RFC1) (80G>A) with the risk of pediatric ALL in China. A total of 176 pediatric ALL patients and 170 matched healthy subjects (as controls) were included and DNA was extracted from the peripheral blood. SNaPshot single nucleotide polymorphism typing was used to determine the genotypes of MTHFR 677C>T, MTHFR 1298A>C, and RFC1 80G>A. All statistical analyses were conducted with SAS software (version 9.2; SAS Institute). There were no significant differences in the genotype and allele frequencies of MTHFR 677C>T, MTHFR 1298A>C, or RFC1 80G>A between patients and controls. No significant correlation was found between the combined genotypes of these polymorphisms and the risk of developing ALL in this study. Furthermore, no significant differences were observed for 677C>T and 1298A>C frequencies between the control and case groups. There was no association between MTHFR 677C>T, MTHFR 1298A>C, or RFC1 80G>A gene polymorphisms and risk of pediatric ALL in the Han Chinese population.

[Clinical Features and Prognostic Factors of Children with Acute Lymphoblastic Leukemia in High-Risk Group].

OBJECTIVE: To explore the clinical features and prognostic factors of pediatric acute lymphoblastic leukemia (ALL) in high-risk (HR) group. METHODS: A total of 421 children with ALL in the Children's Hospital of Soochow University from August 2008 to March 2013 were diagnosed and treated according to the Chinese Children Leukemia Group (CCLG)-2008 Protocol. Among different risk-groups, 148 cases were stratified into the low-risk group and 191 cases were included in the moderate-risk group. Eight-two patients of the high-risk group were analyzed retrospectively for their clinical features, 5-year event-free survival (EFS) rate and overall survival (OS) rate. RESULTS: The median follow-up times of 82 patients were 64 months(3.0-76.3 months), 55 patient achieved complete remission(CR) after 1 cycle of induction chemotherapy(CR rate 67.1%), 25 patients relapsed(30.5%) mainly in very early and early relapse phases, significantly different from the low-risk group (P=0.013), 27 pateitns died(32.9%). The 5-year pEFS and pOS were 57.20% and 58.5%, respectively. Ph+ or BCR/ABL+ and MRD>10-2 on the 33rd day in the high-risk group were 2 main factors influencing EFS and OS according to single factor analysis. Ph+ or BCR/ABL+ was an independent prognostic factor, however, the MRD value on the 33rd day was not statistically significant differente by virtue of COX regression analysis. CONCLUSION: The clinical feature of children with ALL in high risk group display low induction CR rate, high recurrence rate and the lower 5-year pEFS. Ph+ or BCR/ABL+ is regarded as an independent factor of poor prognosis.

mRNA expression profiling of histone modifying enzymes in pediatric acute monoblastic leukemia.

Histone modification is dysregulated in various types of cancers, including hematological malignancies. However, the expression profile of histone-modifying enzymes in pediatric acute monoblastic leukemia (AML FAB M5) has not been investigated. In this study, we evaluated the mRNA expression profile of 85 genes that encode enzymes involved in histone-modification in 27 pediatric AML FAB M5 samples by using a novel real-time PCR array. We obtained a gene cluster consisting of a total of 28 genes (15 up-regulated genes and 13 down-regulated genes). This gene signature revealed up-regulated expression of putative oncogenes GCN5L2, SETD8, KDM5C, AURKA and AURKB, and downregulated putative tumor suppressor genes (TSGs) EP300, PRMT3, PRMT8 and NOTCH2. We investigated possible biological interactions between differentially expressed genes using ingenuity pathway analysis (IPA) and found 12 significant networks. Among these, gene expression, cancer, and embryonic development showed the highest number of networks with 39 focus molecules and had an associated significance score of 68. Further, Rb, CDKN2C, and E2F1 were found to be upstream regulators of histone-modifying enzymes. This study provides additional insights into the molecular pathogenesis of pediatric AML FAB M5. These genes represent interesting targets with potential for diagnostic, prognostic and therapeutic application in pediatric AML patients.

Microarray profiling of bone marrow long non-coding RNA expression in Chinese pediatric acute myeloid leukemia patients.

Long non-coding RNA (lncRNA) plays a role in gene transcription, protein expression and epigenetic regulation; and altered expression results in cancer development. Acute myeloid leukemia (AML) is rare in children; and thus, this study profiled lncRNA expression in bone marrow samples from pediatric AML patients. Arraystar Human LncRNA Array V3.0 was used to profile differentially expressed lncRNAs in three bone marrow samples obtained from each pediatric AML patient and normal controls. Quantitative polymerase chain reaction (qRT-PCR) was performed to confirm dysregulated lncRNA expressions in 22 AML bone marrow samples. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to construct the lncRNA-mRNA co-expression network. A total of 372 dysregulated lncRNAs (difference ≥10-fold) were found in pediatric AML patients compared to normal controls. Fifty-one mRNA levels were significantly upregulated, while 85 mRNA levels were significantly downregulated by >10-fold in pediatric AML, compared to normal controls. GO terms and KEGG pathway annotation data revealed that cell cycle pathway-related genes were significantly associated with pediatric AML. As confirmed by qRT-PCR, expression of 24 of 97 lncRNA was altered in pediatric AML compared to normal controls. In pediatric AML, ENST00000435695 was the most upregulated lncRNA, while ENST00000415964 was the most downregulated lncRNA. Data from this study revealed dysregulated lncRNAs and mRNAs in pediatric AML versus normal controls that could form gene pathways to regulate cell cycle progression and immunoresponse. Further studies are required to determine whether these lncRNAs could serve as novel therapeutic targets and bbdiagnostic biomarkers in pediatric AML.

[Efficacy Analysis of Allogeneic Hematopoietic Stem Cell Transplantation for Children with Severe Aplastic Anemia].

OBJECTIVE: To study the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with severe aplastic anemia (SAA). METHODS: A total of 11 children with SAA were treated with HLA matched siblings (n = 7), umbilical cord blood (n = 2) and haploidentical HSCT (n = 2). RESULTS: Among 11 children patients, 10 patients achieved engraftment, but 3 children patients experienced secondary graft failure, after donor lymphocyte infusions (DLI), they achieved engraftment again. One patient received cord blood transplantation and experienced primary graft rejection, but acquired autologous recovery. The median time for neutrophils to reach over 0.5 × 10(9)/L was 14 days (10-19 days) in the 9 children received bone marrow or bone marrow and peripheral blood allo-HSCT, while the median time for platelets to reach over 20 × 10(9)/L was 17 days (8-42 days). For the patient received double cord blood transplantation, the time of neutrophile and platelet level recovery was 16 days and 41 days, respectively. CONCLUSION: If HLA-matched sibling donor is available, allo-HSCT can be recommended as the first line of treatment for children with SAA. It is feasible for children with SAA to receive allo-HSCT from selective donor, including cord blood and haploidentical HSCT. Donor lymphocyte infusions can improve engraftment.

Clinical features and prognostic significance of TCF3-PBX1 fusion gene in Chinese children with acute lymphoblastic leukemia by using a modified ALL-BFM-95 protocol.

For children with precursor B (pre-B) acute lymphoblastic leukemia (ALL) with TCF3-PBX1 fusion gene, their prognosis has been a controversial topic. From January 2008 to December 2012 in our hospital, 450 patients were diagnosed as ALL. Clinical characteristics of 20 patients with TCF3-PBX1 fusion gene were analyzed retrospectively, which were classified to the intermediate-risk (IR) group according to Chinese Children Leukemia Group-2008 (CCLG-2008) risk-stratification criteria and protocol based on the backbone of BFM 95 trails. Eighty five cases without TCF3-PBX1 in the same IR group were regarded as the comparison group. There were no differences in age, gender, initial white blood cell (WBC) count, status of central nerves system (CNS) at diagnosis and complete remission (CR) rates of bone marrow (BM) between the two groups (P > .05). The 5-year probability of event-free survival (EFS) rates were 84.4 ± 15.6% and 73.5 ± 15.6% in the TCF3-PBX1 group and the comparison group (P = .35), respectively. The 5-year probability of overall survival (OS) rates were 86.0 ± 17.6% and 81.8 ± 17.6% (P = .46), respectively. Relapse rates were 10.5% and 12.9% (P = 1.00), respectively. There were not cases with CNS relapse in the TCF3-PBX1 group. When intensive chemotherapy was used, the TCF3-PBX1 was associated with a favorable outcome in childhood pre-B ALL.

[Clinical significance of glucocorticoid induction test in Chinese childhood acute lymphoblastic leukemia].

OBJECTIVE: Acute lymphoblastic leukemia (ALL) is the most common childhood cancer, while glucocorticoid (GC) is a critical component in multi-agent chemotherapy protocols currently used for the treatment of ALL. The purpose of this study was to investigate the relationship between the glucocorticoid induction test and the clinical features and the prognosis of Chinese childhood ALL. METHOD: The study recruited 309 hospitalized patients (187 male and 122 female) with childhood ALL, the sex, age, initial WBC count, immunophenotype, chromosome and gene expression were recorded. After diagnosis, all patients received GC induction test for 7 days. Then they were divided into prednisone good response (PGR) group and prednisone poor response (PPR) group according to the peripheral lymphoblast count on D8. Early responses to chemotherapy and treatment outcomes of the patients in the two groups were also analyzed. RESULT: Of the 309 patients, 263 belonged to PGR group and 46 belonged to PPR group. Initial WBC count was higher in PPR group than in PGR group (86.30×10(9)/L vs. 30.97×10(9)/L, P < 0.01) . B lineage ALL showed more sensitive to GC than T-ALL (86.6% vs. 60%, P < 0.05). Different initial-risk-group's sensitivity to GC differed from one another (high-risk:51.4%, medium-risk: 82.7%, standard risk: 93.7%, P < 0.0125). There was no significant difference between two groups in chromosomal karyotypes (P > 0.05). BCR-ABL positive ALL showed lower sensitivity to GC (P < 0.05) , while MLL, TEL-AML1, E2A-PBX1 positive rates in two groups were of no statistical significance (P > 0.05). Bone marrow was reviewed on D15 and D33, and the CR rates in PGR group were significantly higher than that in PPR group (D15: 60.5% vs. 32.6%, D33: 94.6% vs. 73.3%, P < 0.01) ; Minimal residual disease (MRD) levels were examined on D33, W12, and both were much lower in PGR group (D33: P < 0.01, W12: P < 0.05). Of the PGR group 215 patients (81.7%) remained continuously in complete remission (CCR) while only 28 cases (60.9%) in PPR group did so. The CCR rate was much higher in PGR group than that in PPR group (P < 0.01). CONCLUSION: Closely related to clinical features and the outcomes of treatment, GC induction test is also an important prognostic factor in Chinese childhood ALL.

[The expression and clinical significance of miR-203 in pediatric acute leukemia].

OBJECTIVE: To investigate the methylation, expression and clinical significance of miR-203 in pediatric acute leukemia. METHODS: The methylation status of miR-203 promoter CpG islands was detected with methylation-specific polymerase chain reaction. The expression of miR-203 was detected by Taqman real- time quantitative polymerase chain reaction. And the clinical significance of miR-203 in pediatric acute leukemia (ALL) was also analyzed. RESULTS: The promoter of miR-203 was unmethylated in all of 31 pediatric acute lymphoblastic leukemia, all of 15 pediatric acute myeloid leukemia (AML) and all of 23 controls. The relative expression levels of miR-203 in controls, pediatric acute leukemia, ALL and AML were 16.93±6.31, 48.97±10.38, 55.88±12.91, 24.28±9.10 respectively. The results indicated that miR-203 was significantly up- regulated in pediatric acute leukemia (P=0.011) and ALL (P=0.009), not in pediatric AML (P=0.514) compared with control. The expression of miR-203 was significantly related with the gender, immunophenotype, chromosome, fusion gene, BCR-ABL, SIL-TAL1 and prednisone experiment in pediatric ALL and the gender, chromosome, fusion gene, SIL-TAL1 in pediatric acute leukemia (P<0.05). And in risk stratification pairwise comparisons, the expression of miR-203 in the medium-risk and high-risk groups appeared significantly different (P=0.022). CONCLUSION: miR-203 may not be regulated with methylation mechanism in pediatric acute leukemia. miR- 203 may be a protooncogene involved in the formation of pediatric acute leukemia and ALL. Further analyses indicated that high expression of miR-203 may be associated with poor prognosis of pediatric ALL and acute leukemia.

[The effect of the adverse events with thiopurine S-methyltransferase gene mutation on outcome of childhood acute lymphoblastic leukemia].

OBJECTIVE: To investigate thiopurine S-methyltransferase (TPMT) activity and gene promoter polymorphism to probe its significance of individual chemotherapy in acute lymphoblastic leukemia (ALL) children. METHODS: HPLC method was carried out to determine TPMT activity (n=100), which activity at newly diagnosed. At the same time determination of TPMT activity in healthy children (n=180), these children come from the health care clinic. Using online primer3 software design primers, PCR products were purified. To sequence TPMT gene of the patients with clinical events(n=30). According to the method to analysis of correlation between TPMT activity and toxicity. RESULTS: The average TPMT activities were (31.72±10.31) nmol·g⁻¹Hb·h⁻¹ and (30.70±9.67) nmol·g⁻¹Hb·h⁻¹ in ALL and healthy groups respectively, without gender differences of TPMT activities (P=0.45) in both groups. The TPMT activity with clinical events in newly diagnosed ALL patients (n=30) was (24.07±11.43) nmol·g⁻¹Hb·h⁻¹. There are significant differences of TPMT activities between severe bone marrow suppression [(20.96±7.24) nmol·g⁻¹Hb·h⁻¹] and ALL patients with clinical events groups (P<0.05). The TPMT activity of (40.46±8.18) nmol·g⁻¹Hb·h⁻¹ in recurrence children was also significantly different (P<0.05). TPMT activity in severe liver toxicity group was not significantly different (P=0. 930). Of TPMT gene sequencing in ALL patients with clinical events, only 3 children were heterozygosity mutations of TPMT*3C, while others homozygous genotype. There were significant differences of TPMT activities between heterozygosity genotype [(11.99±1.32) nmol·g⁻¹Hb·h⁻¹] and homozygous genotype groups [(24.95±11.32) nmol·g⁻¹Hb·h⁻¹] (P<0.05). There were five kinds of variations at the vicinity of the promoter region of -100 of tandem repeats (VNTR) polymorphism（*V3/*V3、*V3/*V4、*V4/*V4、*V5/*V5、*V4/*V6）without significant differences of TPMT activities among five kinds (P=0.186). CONCLUSION: TPMT activity was related to the gene polymorphism. TPMT activity determination had prognostic value and guided individualized treatment.

[Clinical significance of dynamic monitoring the minimal residual disease in childhood B-lineage acute lymphoblastic leukemia by multiparameter flow cytometry].

This study was aimed to explore the clinical significance of monitoring level of minimal residual disease (MRD) at different time point in B-lineage childhood acute lymphoblastic leukemia (B-ALL). Two hundred and six children with B-ALL were enrolled in this study from Augest 2008 to September 2011 in our hospital. MRD levels were detected by flow cytometry at day 15, 33 and week 12 after initial chemotherapy. The event-free survival (EFS) for patients based on MRD levels measured at different stages of chemotherapy were compared by Kaplan Meier analyses. The results showed that out of 206 cases 196 cases achieved complete remission (CR) after induction therapy (CR rate 95.1%), the 1- and 3-year EFS rate were (92.7 ± 1.8)% and (78.7 ± 3.7)%, respectively, and the 3-year EFS rate was (85.6 ± 4.9)% in standard risk group, (82.1 ± 5.8)% in intermediate risk group and (58.1 ± 9.2)% in high risk group, there was significant statistical difference between above mentioned 3 groups (P < 0.001). The MRD analysis at different time points showed that the higher the MRD level, the lower the 3-year EFS rate of children with ALL, in which the 3-year EFS rate of MRD ≥ 10(-2) at day 15, MRD ≥ 10(-3) at day 33 and MRD ≥ 10(-3) at week 12 were significantly lower. The MRD ≥ 10(-3) at week 12 was proven to be an independent predictor by multivariate Cox proportional-hazards regression model. The 3-year EFS rate for patients with MRD < 10(-3) and MRD ≥ 10(-3) at week 12 were (86.3 ± 4.1)% vs (55.8 ± 9.1)% (P < 0.05); 8 relapsed among 98 cases with negative MRD (MRD < 10(-4)) at day 33, 19 relapsed among 108 cases with positive MRD at day 33 between the two groups for recurrence rate has significant difference (P < 0.05). It is concluded that dynamically monitoring MRD by multi-parameter flow cytometry can precisely evaluate treatment response, judge treatment outcome and predict relapse in childhood B-ALL. The MRD 10(-2) at day 15, MRD 10(-3) at day 33 and MRD 10(-3) at week 12 should be considered as the best cut-off. MRD ≥ 10(-3) at week 12 was proven to be an independent factor of poor prognosis.

[Relationship between genetic polymorphism of multidrug resistance 1 gene and the risk of childhood acute lymphocytic leukemia].

OBJECTIVE: To investigate the relationship between genetic polymorphism in exon 12 C1236T, exon 21 G2677T/A and exon 26 C3435T of the multidrug resistance 1 (MDR1) gene and the risk of childhood acute lymphocytic leukemia (ALL). METHOD: A total of 176 patients with ALL and a cohort of 170 matched healthy subjects were included. SNaPshot SNP typing was used to determine the genotypes of MDR1 C1236T, G2677T/A, C3435T. Based on the clinical data, the relationship between genetic polymorphism of MDR1 and the risk of childhood ALL was analyzed. RESULT: There was significant difference in the distribution of genotype of MDR1 C3435T between the group of controls and cases. The mutant homozygous TT genotype was found to be associated with occurrence of ALL (P = 0.000; OR = 4.504). The data show evidence of pairwise linkage disequilibrium between the three common SNPs (C1236T-G2677T/A-C3435T). The haplotypes of TTT, TGC, CGC and CAC were predominant. The haplotype CGT distributed significantly differently between the groups of controls and cases (P = 0.034). The frequency of the haplotype TTT/TTT in the high risk group was higher than the other groups (P = 0.037). CONCLUSION: The present findings suggest that 3435C→T polymorphism in MDR1 gene may be a genetic susceptibility factor for ALL. The haplotype of MDR1 (C1236T-G2677T/A-C3435T) could be the clinical parameter at diagnosis.

[Analysis of clinical features and prognostic significance of childhood T-lineage acute lymphoblastic leukemia].

This study was aimed to explore the clinical features and prognosis outcome of childhood T-cell acute lymphoblastic leukemia (T-ALL). The clinical data of 38 cases of newly diagnosed T-ALL from Jan 2005 to Aug 2010 were analyzed retrospectively, and 78 cases of B-ALL with intermediate and high risk were collected as control group, then the sensitive rate of patients to prednisone pretreatment, complete remission (CR) rate at day 33 after induction chemotherapy, relapse rate and 3-year event-free survival (EFS) were compared between T-ALL and B-ALL children. The results showed that no significant statistic difference were found in distribution of age, infiltration of liver, spleen and lymph nodes as well as central nervous system disease, chromosome abnormality, expression level of fusion gene and so on between T-ALL and B-ALL groups (p > 0.05), but there were significant differences in sex and number of cases with WBC count ≥ 50 × 10(9)/L between them (p < 0.05). The sensitive rate of T-ALL and B-ALL patients to prednisone pretreatment was 51.9% and 89.3% respectively (p < 0.05). The ratio failed to achieve CR at day 33 after induction chemotherapy was 15.4% and 8.1% in the two groups (p > 0.05). The relapse rate of T-ALL and B-ALL cases was 30.8% (8/26) and 14.9% (11/74) respectively (p > 0.05). The time from CR to relapse was (9.78 ± 3.48) month and (21.28 ± 14.32) month (p < 0.05). The 3 year EFS of T-ALL cases with intermediate and high risk was (37.5 ± 17.1)% and (22.2 ± 9.8)%, while 3 year EFS of B-ALL cases was (66.7 ± 7)% and (51.7 ± 9.3)% respectively (p < 0.05) according to Kaplan-Meier survival curve. It is concluded that as compared with B-ALL cases, the male ratio and initial WBC count are higher, moreover the early response to prednisone pretreatment and 3 year EFS are poor in T-ALL cases, the prognosis outcome is poor also.

[Preliminary study of gene expression profile associated with risk classification of childhood patients with acute lymphoblastic leukemia].

OBJECTIVE: To explore genes associated with risk classification of childhood acute lymphoblastic leukemia (ALL) by gene chip technology. METHODS: Group A and B were both composed of three newly diagnosed ALL cases with standard risk. After re-evaluation, group B was relegated to high-risk. The control group was composed of three idiopathic thrombocytopenic purpura (ITP) patients. The gene expression profiles of group A and B were studied by Illumina Human-6 Beadchip. Eighty-two ALL patients were selected as the experimental group and 21 with normal bone marrow as control group for real-time quantitative RT-PCR (RQ-PCR). RESULTS: (1) There were 19 genes expressed differently between group B and A, including 14 up-regulated as ABCC4 and BCL11A, 5 down-regulated genes as TOP2A. (2) ABCC4 and BCL11A were validated by RQ-PCR and their expression level was higher in the high risk group than in the standard risk group (P < 0.05). The gene expression level in the group A and B was higher than that in the normal control group (P < 0.01). TOP2A was also validated by RQ-PCR and its expression level in the high risk group was lower than that in the standard risk group (P < 0.05). The gene expression level in the groups A and B was lower than that in the normal control group and the difference was statistically significance (P < 0.01). (3) There was a significant difference in the expression level of ABCC4 between the remission and unremission patients (P < 0.05). There was no significant difference in the expression level of BCL11A between different clinical indicators (P > 0.05). There was significant difference in the expression level of TOP2A between remission and prednisone good responder groups (P < 0.05). CONCLUSIONS: Fourteen genes studied were involved in the pathogenesis and drug resistance mechanism in childhood ALL patients. Investigation of gene expression profile will be helpful for predicting drug resistance, prognosis, early intervention and target therapy in childhood ALL.

The significance of detecting WT1 expression in childhood acute leukemias.

WT1 (Wilms' tumor gene 1) overexpression is implicated in the prognosis of acute leukemia. The purpose of this study was to investigate WT1 expression and its clinical implication in childhood acute leukemia (AL) in Chinese population. Bone marrow specimen from 200 children at different stages of acute leukemia and from 21 children without leukemia were studied. The WT1 expression at diagnostic marrow specimen in both acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL) was higher than control group, whereas WT1 expression in AML was higher than in ALL, and WT1 expression level in relapse in ALL increased more significantly than in AML. The WT1 expression level showed positive correlation with the hypodiploidy and BCR-ABL fusion gene in acute leukemia. A rapidly decrease of WT1 expression level predicted a good response to the induction therapy and low expression of WT1 correlates with remission status. This study suggested that WT1 expression levels in acute leukemia can potentially be a marker for evaluating therapeutic efficacy, correlating with monitoring minimal residue disease, and predicting hematological relapse in children acute leukemia.

[Expression of CYP3A5 mRNA in children with acute leukemia].

OBJECTIVE: The cytochrome P450 subfamily IIIA5 (CYP3A5) gene is responsible for the metabolism of many clinically used anticancer agents. So far the studies on CYP3A5 gene has only been focused on the leukemia cell lines. This study examined the polymorphism of CYP3A5 and tried to find the possible relationship between CYP3A5 gene expression and treatment outcome or prognosis in children with acute leukemia. METHODS: The genotype distribution of CYP3A5-6986A/G gene polymorphism was detected with the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 66 children with newly diagnosed acute leukemia (AL) and 22 control individuals. Quantitative real-time RT-PCR was used to examine wt-CYP3A5 and SV1-CYP3A5 mRNA levels in the bone marrow. RESULTS: Three genotypes of CYP3A5-6986A/G polymorphisms were found: CYP3A5*1/*1, CYP3A5*1/*3 and CYP3A5*3/*3. There were significant differences in the wt-CYP3A5 mRNA expression among the AL patients with different genotypes (p<0.05). In patients with acute lymphocytic leukaemia (ALL), the complete remission (CR) rate in the group with a low expression of wt-CYP3A5 mRNA was significantly higher than that in the group with a high expression (p<0.05). A dynamic monitoring for wt-CYP3A5 mRNA expression was performed in two cases of ALL. The expression increased before ALL relapse compared with that in CR in a patient, while in the other patient, the expression was kept in a low level and the patient remained in CR CONCLUSIONS: wt-CYP3A5 mRNA expression was associated with the treatment outcome and prognosis in children with AL. Dynamic monitoring for wt-CYP3A5 mRNA expression in the bone marrow may be useful in the evaluation of the disease severity in childhood acute leukemia.

[Relationship between pharmacokinetics and efficacy and toxicity of daunorubicin in children with acute leukemia].

OBJECTIVE: To study relationship between daunorubicin (DNR) pharmacokinetics and efficacy and toxicity in children with acute leukemia. METHODS: (1) The concentration of DNR in plasma of children with acute leukemia was determined by high performance liquid chromatography (HPLC)-fluorescence detection method. Plasma was sampled frequently from the start of the infusion till the end of 24 h. DNR pharmacokinetics was studied by determination of the concentrations. (2) Efficacy and toxicity were monitored in each period after chemotherapy. Laboratory studies included examination of bone marrow, white blood cell count, electrocardiogram, echocardiogram, myocardial enzymogram, the liver and kidney function. RESULTS: (1) DNR was eliminated from plasma in a two-compartment manner. The maximum concentration was seen 1 - 3 h after infusion. Cmax was 63.50 microg/L. Tmax was 1.45 h. The concentration decreased quickly to a low level of about 11.52 microg/L from the end of 2 hours infusion. There was a large inter-individual difference in pharmacokinetic parameters of DNR. The difference of CL was 9-fold, AUC was 8-fold, Cmax was 5-fold. (2) CL of male patients [57.99 L/(h.m(2))] was significantly lower than that of female patients [93.71 L/(h.m(2))] (P < 0.05). Tmax of children older than 6 years was 1.1 h, and that of children younger than 6 years was 1.8 h (P < 0.05); Cmax of children older than 6 years was 90.77 microg/L, younger than 6 years was 57.44 microg/L (P < 0.05). CONCLUSION: (1) There is a large inter-individual difference in pharmacokinetic parameters of DNR in children. It may predict individual variety of efficacy and toxicity. Therapeutic drug monitoring is important. (2) Male patients and children older than 6 years had a higher bioavailability and lower metabolism, toxicity may easily occur in such children, therefore they may need lower dose.