[The Mechanism of Artesunate Combined with Cytarabine and/or Daunorubicin on the Apoptosis of MV4-11 MLL-rearranged Acute Myeloid Leukemia Cell Line].

OBJECTIVE: To investigate the effect and mechanism of artesunate (ARTS) combined with cytarabine(Ara-C) and/or daunorubicin (DNR) on the proliferation and apoptosis of MV4-11 human mixed-lineage leukemia rearranged（MLL-r） acute myeloid leukemia (AML) cell line. METHODS: CCK-8 assay was used to detect the proliferation effect of individual or in combination of ARTS, DNR, Ara-C on MV4-11 cells. The IC50 of ARTS, DNR and Ara-C was calculated separately. The cell apoptosis and expression of receptors DR4 and DR5 were detected by flow cytometry. Western blot was used to detect the expression of Caspase-3 and Caspase-9 in each groups. RESULTS: The inhibition effect of ARTS, Ara-C and DNR on the proliferation of MV4-11 were all dose-dependently (r=0.99, 0.90 and 0.97, respectively). The IC50 of ARTS, Ara-C and DNR on MV4-11 for 48 hours were 0.31 µg/ml, 1.43 µmol/L and 22.47 nmol/L, respectively. At the dose of ARTS 0.3 µg/ml， Ara-C 1.0 µmol/L and DNR 15 nmol/L, the proliferation rate for 48 hours of the tri-combination treatment was significantly lower than that of the bi-combination treatment, while both were significantly lower than that of the individual treatment (all P＜0.05). In terms of bi-combination treatment, the cells proliferation rate for 48 hours of the ARTS+Ara-C group was significantly lower than that of the ARTS+DNR group, while both were significantly lower than that of the Ara-C+DNR group (all P＜0.05). The cooperativity index (CI) of bi- and tri-combination treatment were all less than 1. After 48 hours of drug action, the cell apoptosis rate of the ARTS+DNR+Ara-C group was significantly higher than that of the Ara-C+DNR group, while both were significantly higher than that of the ARTS+DNR group (all P＜0.05). Meanwhile, the was no statistical difference between the cells apoptotic rate of the ARTS+DNR+Ara-C group and the ARTS+Ara-C group (P>0.05). The expression of DR4 and DR5 also showed no difference between control group and drug group. Compared with the DNR+Ara-C group, the expressions of Caspase-3 were significantly down-regulated in both the ARTS+DNR+Ara-C group and the ARTS+Ara-C group (all P＜0.05). The down-regulation of Caspase-3 expression was the most significantly in the combination group of three drugs, while the Caspase-9 expressions in different groups showed no apparent change. CONCLUSION: The in vitro study showed that tri-combination of ARTS+Ara-C+DNR and bi-combination of ARTS+Ara-C could inhibit the proliferation and promote apoptosis of MV4-11 cell line. The inhibition effect of these two combinations were significantly superior to that of the traditional Ara-C+DNR treatment. The mechanism underlying this finding may be identified by the down regulation of Caspase-3, while no altered expression was observed of Caspase-9, DR4 and DR5.

[Clinical Efficacy of R-EDOCH Protocol in the Treatment of Newly Diagnosed Double Expression Lymphoma].

OBJECTIVE: To investigate the clinical efficacy of R-EDOCH protocol in the treatment of newly diagnosed double expression lymphoma. METHODS: The clinical data of 51 patients with newly diagnosed double expression lymphoma treated by R-EDOCH protocol were retrospectively analyzed in the period from May 2012 to October 2017, then overall remission rate (ORR), disease control rate (DCR), progression-free survival (PFS) rate and total survival (OS) rate were evaluated; moreover the patients were grouped according to IPI score and whether accepting hematopoietic stem cell transplantation(HSCT) and the clinical efficacy was compared. RESULTS: The ORR was 96.08% (49/51) and DCR was 100.00% (51/51) in all patients. Six cases out of 51 patients (11.76%) relapsed and progressed during the followed-up. The followed-up showed that 2 year-PFS rate and OS rate were 84.31% (43/51) and 94.12% (48/51) respectively. The ORR, SD rate, 2 year-PFS rate and OS rate in the patients with IPI 0-2 and 3-5 scores were no statistically different(p>0.05); the 2 year-PFS and OS rates between patients in subgroup of IPI 0-2 and 3-5 scores also were not statistically different (p>0.05), no matter whether the patients received auto-HSCT or not. The comparison of 2 year-PFS and OS rates in auto-HSCT patients and non-auto-HSCT patients showed no statistical difference(p>0.05). CONCLUSION: The R-EDOCH protocol in treatment of newly diagnosed double expression lymphoma possess the good overall clinical efficacy, the combination of R-EDOCH with auto-HSCT displays ascending trend of PFS.

[Pathogenic Genes of A Hereditary Hemorrhagic Telangiectasia Pedigree].

OBJECTIVE: To identify the mutation of ENG and ALK1 genes in a hereditary hemorrhagic telangiectasia pedigree. METHODS: 14 exons of ENG gene and 9 exons of ALK1 gene in 11 menbers of this pedigree 4 generation were amplified by reverse transcription-polymerase chain reaction (RT-PCR), the PCR products were screened by direct sequencing. RESULTS: A nonsense mutation c.447G > A was found in exon 4 of ENG gen of the pedigreee, resulting in change of Trp 149 into Stop, while no gene mutation was found in ALK1 gene. CONCLUSION: The hereditary hemorrhagic telangiectasia in this pedigree is caused by the nonsense mutation c.447G > A in ENG gene.

[Mutation analysis of UGT1A1 gene in patients with unconjugated hyperbilirubinemia].

OBJECTIVE: To analyze potential mutations of uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene in patients with unconjugated hyperbilirubinemia, and to explore the correlation between the mutations and total serum bilirubin levels. METHODS: Genomic DNA was extracted from peripheral blood samples of patients. Coding sequence and promoter region of the UGT1A1 gene were amplified. Mutations were identified through DNA sequencing. RESULTS: Mutations of the UGT1A1 gene were found in 46 out of 61 patients with unconjugated hyperbilirubinemia. Five types of mutations were detected, with a decreasing order of 211G>A, TA insertion in the TATAA promoter element, 686C>A, 1091C>T and 1352C>T. Compared with those carrying a single homozygous mutation or compound heterozygous mutations, total serum bilirubin was higher in those carrying a homozygous mutation in combination with other heterozygous mutations (P< 0.05). Based on the UGT1A1 gene mutations and level of total serum bilirubin, 44 patients were diagnosed with Gilbert syndrome, and 2 were diagnosed with Crigler-Najjar syndrome type 2. CONCLUSION: The level of total serum bilirubin is correlated with the number of UGT1A1 gene mutations as well as their heterozygous or homozygous status.

[Effect of BCL11A gene on transcription of γ-globin gene].

This study was aimed to explore the effect of BCL11A gene on transcription of γ-globin gene in K562 cells. B-cell lymphoma/leukemia 11A (BCL11A) gene was silenced by small interfering RNA (siRNA) expression vectors in K562 cells (human erythroblastic leukemia cell line). Gamma-globin mRNA level in K562 cells was determined by RT-PCR. Association between the BCL11A gene and γ-globin gene transcription was explored by comparison of mRNA levels. The results indicated that the silence rate of the BCL11A gene in K562 cells by 4 siRNA expression vectors was 49.7%, 55.4%, 78.2%, and 84.1%, respectively. The siRNA expression vector with 84.1% silence rate was transfected into K562 cells, transcription level of γ-globin mRNA in K562 cells transfected with siRNA expression vector increased 2.4 times as compared with control K562 cells. It is concluded that level of γ-globin mRNA increases when the BCL11A gene is silenced. It indicates that the BCL11A gene may be a negative regulator for γ-globin gene expression.

[Novel double heterozygous mutations on Met306Val and Thr181Asn related to a hereditary coagulation factor VII deficiency].

OBJECTIVE: To identify the genetic defect of coagulation factor VII in a Chinese family with hereditary FVII deficiency. METHODS: Peripheral blood samples were collected from the proband of hereditary FVII deficiency, female, aged 15, 4 members of her family, and 100 healthy persons. Genomic DNA was isolated. All the exons and exon-intron boundaries of FVII gene were amplified by PCR, then the PCR products were sequenced by direct sequencing. Restrictive endonuclease analysis was performed in all of the family members and the 100 healthy donors to exclude gene polymorphism. Biostructural analysis of the mutated FVII was completed by molecular modeling. RESULTS: Double heterozygous mutations in the proband were identified: A-->G mutation at position 10833 and C-->A mutation at position 9643, resulting in Met306Val and Thr181Asn substitution respectively. Heterozygosity for Met306Val was confirmed in the proband's mother and her elder sister; heterozygosity for Thr181Asn was confirmed in the proband's father. It was found by computer simulated molecular model that the Met306Val replacement, which was located on the surface of the FVII molecule, might cause steric hindrance and change the configuration and function of FVII protein. CONCLUSION: Double heterozygous mutations for Met306Val and Thr181Asn in FVII gene have been found in a proband with hereditary FVII deficiency. The Met306Val substitution in FVII gene is a novel mutation in hereditary FVII deficiency. The heterozygous mutation of FVII gene may change the configuration of FVII protein and result in FVII dysfunction.