OBJECTIVETo clarify the regulatory elements of Rad51 gene in its 5'flanking region.

METHODSVarious constructs were obtained by cloning different DNA fragments into pGL3 reporter vector. These constructs were then introduced into osteosarcoma cell line U2-OS by calcium phosphate method for transient expression of reporter gene, and luciferase activities were measured by luciferase assay.

RESULTSCells transfected with pGL3 constructs containing fragment -964 to +1430 and -733 to +1430 showed high luciferase activities. Obvious elevation of luciferase activities was also observed in cells transfected with pGL3 constructs containing four shorter derivative fragments -964 to -412, -746 to -412, -651 to -412 and -536 to -412. The highest luciferase activities were measured in transfected cells with plasmids containing fragment -964 to -412, and the lowest were in transfected cells with plasmids containing fragment -536 to -412. Luciferase activities in transfected cells with plasmids containing fragment -651 to -412 were higher than that in transfected cells with plasmids containing fragment -746 to -412.

CONCLUSIONIt is believable that the basic transcription-promoting element (promoter) for Rad51 gene resides between -536 to -412, and two transcription-enhancing elements (enhancer) or binding sites of positive transcription factors reside between -651 to -536 and -964 to -746, whereas one transcription-inhibiting element (silencer) or binding site of negative transcription factor may reside between -746 to -651.

5' Flanking Region ; DNA Repair ; DNA-Binding Proteins ; genetics ; Humans ; Promoter Regions, Genetic ; Rad51 Recombinase

The generation of a tau-V337M point mutation mouse model using gene editing technology can provide an animal model with fast disease progression and more severe symptoms, which facilitate the study of pathogenesis and treatment of Alzheimer's disease (AD). In this study, single guide RNAs (sgRNA) and single-stranded oligonucleotides (ssODN) were designed and synthesized in vitro. The mixture of sgRNA, Cas9 protein and ssODN was microinjected into the zygotes of C57BL/6J mice. After DNA cutting and recombination, the site homologous to human 337 valine (GTG) in exon 11 was mutated into methionine (ATG). In order to improve the efficiency of recombination, a Rad51 protein was added. The female mice mated with the nonvasectomy male mice were used as the surrogates. Subsequently, the 2-cell stage gene edited embryos were transferred into the unilateral oviduct, and the F0 tau-V337M mutation mice were obtained. Higher mutation efficiency could be obtained by adding Rad51 protein. The F0 tau-V337M point mutation mice can pass the mutation on to the F1 generation mice. In conclusion, this study successfully established the first tau-V337M mutation mouse by using Cas9, ssODN and Rad51. These results provide a new method for developing AD mice model which can be used in further research on the pathogenesis and treatment of AD.
Animals ; Male ; Female ; Mice ; Humans ; CRISPR-Cas Systems/genetics* ; RNA, Guide, CRISPR-Cas Systems ; Rad51 Recombinase/genetics* ; Mice, Inbred C57BL ; Disease Models, Animal ; Recombination, Genetic

This study was purposed to investigate the relationship between NQO1C(609T), RAD51(G135C), XRCC3(C241T) single nucleotide polymorphisms and incidence of acute lymphoblastic leukemia (ALL). NQO1C(609T), RAD51(G135C), XRCC3(C241T) genotypes were detected by PCR-RFLP in 170 patients with de novo ALL and 458 normal persons as control. The results indicated that the genotype ratio of NQO1C(609T), RAD51(G135C) and XRCC3(C241T) in single genotype analysis showed no statistical difference between ALL patients and normal controls, which suggested that the single genotype affect onset of ALL without statistical significance. In combined genotype analysis, presence of both variants for NQO1C(609T) and RAD51(G135C) increased onset risk of ALL with myeloid antigen positive and with balanced translocation (OR value 5.553 and 2.618 respectively); the presence of homozygosity variant for NQO1C(609T) increased onset risk of ALL in the country-children (OR = 2.541). In conclusion, the combined effect of NQO1C(609T), RAD51(G135C) and XRCC3(C241T) genotypes may promote occurrence of ALL, which suggests that the combined analysis of 3 genotypes has more predictive significance for ALL than single genotype analysis.
Adolescent ; Adult ; Aged ; Case-Control Studies ; Child ; DNA Repair ; DNA-Binding Proteins ; genetics ; Female ; Humans ; Male ; Middle Aged ; NAD(P)H Dehydrogenase (Quinone) ; genetics ; Polymorphism, Single Nucleotide ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; Rad51 Recombinase ; genetics ; Young Adult

OBJECTIVETo investigate the impact of polymorphisms of DNA homologous recombination (HR) repair genes RAD51-G135C and XRCC3-C241T on the prognosis of acute myeloid leukemia (AML) with inv(16)/t(16;16)(CBFbeta-MYH1).

METHODSOne hundred and three de novo inv(16)/t(16;16) (CBFbeta-MYH11) AML patients were followed-up and retrospectively analyzed. Polymorphisms of RAD51-G135C and XRCC3-C241T were detected by PCR-RFLP. The prognostic factors,including sex, age, white blood cell count, platelet count, hemoglobin level, karyotype, KIT mutation, RAD51-G135C and XRCC3-C241T polymorphisms at diagnosis, for complete remission (CR) achievement, overall survival (OS) and relapse-free survival (RFS) were analyzed by univariate and multivariate analyses.

RESULTSThe median follow-up of all patients was 28 (1 - 106) months. The overall CR rate was 92.2%. The estimated 5-year OS and RFS rates were 43.6% (95% CI 37.7% - 49.5%) and 26.4% (95% CI 21.1% - 31.7%), and the median OS and RFS were 53 (95% CI 133.4 - 72.7) and 27 (95% CI 22.9 - 31.1) months, respectively. In multivariate analysis, higher WBC (P = 0.004) and older than 30 years of age (P = 0.035) were independent poor factors for CR achievement, the XRCC3-241T variant (P = 0.007) and higher WBC (P = 0.009) were independent poor factors for 5-year RFS, and higher WBC (P = 0.002) and trisomy 8 (P = 0.035) were independent poor factors for 5-year survival. Polymorphism of RAD51-G135C had no significant impact on the prognosis.

CONCLUSIONThe XRCC3-241T variant is an independent poor prognostic factor for AML with inv(16)/t(16;16)/CBFbeta-MYH11.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Chromosome Inversion ; Chromosomes, Human, Pair 16 ; DNA-Binding Proteins ; genetics ; Female ; Humans ; Karyotype ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; Male ; Middle Aged ; Oncogene Proteins, Fusion ; genetics ; Polymorphism, Single Nucleotide ; Prognosis ; Rad51 Recombinase ; genetics ; Young Adult

The transition from spermatogonia to spermatocytes and the initiation of meiosis are key steps in spermatogenesis and are precisely regulated by a plethora of proteins. However, the underlying molecular mechanism remains largely unknown. Here, we report that Src homology domain tyrosine phosphatase 2 (Shp2; encoded by the protein tyrosine phosphatase, nonreceptor type 11 [Ptpn11] gene) is abundant in spermatogonia but markedly decreases in meiotic spermatocytes. Conditional knockout of Shp2 in spermatogonia in mice using stimulated by retinoic acid gene 8 (Stra8)-cre enhanced spermatogonial differentiation and disturbed the meiotic process. Depletion of Shp2 in spermatogonia caused many meiotic spermatocytes to die; moreover, the surviving spermatocytes reached the leptotene stage early at postnatal day 9 (PN9) and the pachytene stage at PN11-13. In preleptotene spermatocytes, Shp2 deletion disrupted the expression of meiotic genes, such as disrupted meiotic cDNA 1 (Dmc1), DNA repair recombinase rad51 (Rad51), and structural maintenance of chromosome 3 (Smc3), and these deficiencies interrupted spermatocyte meiosis. In GC-1 cells cultured in vitro, Shp2 knockdown suppressed the retinoic acid (RA)-induced phosphorylation of extracellular-regulated protein kinase (Erk) and protein kinase B (Akt/PKB) and the expression of target genes such as synaptonemal complex protein 3 (Sycp3) and Dmc1. Together, these data suggest that Shp2 plays a crucial role in spermatogenesis by governing the transition from spermatogonia to spermatocytes and by mediating meiotic progression through regulating gene transcription, thus providing a potential treatment target for male infertility.
Animals ; Cell Cycle Proteins/genetics* ; Cell Line ; Cell Survival ; Chondroitin Sulfate Proteoglycans/genetics* ; Chromosomal Proteins, Non-Histone/genetics* ; Gene Expression Regulation ; Gene Knockdown Techniques ; Infertility, Male ; Male ; Meiosis/genetics* ; Mice ; Mice, Knockout ; Mice, Transgenic ; Phosphate-Binding Proteins/genetics* ; Protein Tyrosine Phosphatase, Non-Receptor Type 11/genetics* ; Rad51 Recombinase/genetics* ; Real-Time Polymerase Chain Reaction ; Spermatocytes/metabolism* ; Spermatogenesis/genetics* ; Spermatogonia/metabolism*

OBJECTIVETo investigate the relationship between DNA homologous recombination (HR) repair genes RAD51-G135C/XRCC3-C241T polymorphisms and development of acute myeloid leukemia (AML) with recurrent chromosome translocation.

METHODSGenomic DNA was extracted from bone marrow cells of 625 de novo AML patients and peripheral blood cells of 806 patient family members and 704 unrelated volunteers. Genotypes of RAD51-G135C and XRCC3-C241T were analyzed by PCR-RFLP. Cell lines with genotypes differed from XRCC3-C241T were selected and irradiated in vitro. The CBFβ-MYH11 fusion gene was detected by TaqMan real-time PCR.

RESULTSThe XRCC3-C241T variant (C/T + T/T) showed 6.22-fold and 6.99-fold increase in the risk of developing the AML with inv(16)/t(16;16)/CBFβ-MYH11 as compared with the volunteer and family member controls respectively; the RAD51-G135C homozygote-type (C/C) variant showed 0.87-fold (P = 0.010) and 1.15-fold (P = 0.001) respectively increase in the risk of this subtype AML. In the irradiated group, the CBFβ-MYH11 mRNA level in HL-60 cells was 59.49 times increased than that in KG1a cells. However, the RAD51-G135C and XRCC3-C241T variants had no correlations with the risk of development of t(15;17)/PML-RARα(+)AML, t(8;21)/AML1-ETO(+) AML and 11q23 AML subtypes.

CONCLUSIONThe XRCC3-C241T variant and the RAD51-G135C homozygote-type significantly increase the risk of the development of AML with inv(16)/t(16;16)/CBFβ-MYH11.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Case-Control Studies ; Child ; Child, Preschool ; DNA-Binding Proteins ; genetics ; Female ; Genetic Predisposition to Disease ; Genotype ; Humans ; Leukemia, Myeloid, Acute ; etiology ; genetics ; Male ; Middle Aged ; Oncogene Proteins, Fusion ; genetics ; Polymorphism, Single Nucleotide ; Rad51 Recombinase ; genetics ; Translocation, Genetic ; Young Adult