OBJECTIVETo investigate the relationship between RAD51-G135C and XRCC3-C241T single nucleotide polymorphisms and onset of acute myeloid leukemia (AML).

METHODSThe study was performed in 2 groups: AML patient group and normal person group as control group. Genomic DNA was extracted from peripheral blood cells of 545 AML patients and 1 034 normal persons. Genotypes of RAD51-G135C and XRCC3-C241T were analyzed by TaqMan probe technology and the ralatienship between RAD51-G135C/XRCC3-C241T polymorphisms and onset of acute myeloid leukemia was investigated.

RESULTSCompared with the control group, RAD51-G135C homozygous mutant (CC) could significantly increase the risk of AML patients (OR=3.07), and there was no statistical relationship between heterozygous mutant (GC) of RAD51-G135C and onset of AML. There was no statistical relationship between homozygous mutant (TT) of XRCC3-C241T and onset of AML, and the XRCC3-C241T heterozygous mutation type (CT) increased the risk of AML patients (OR=0.66).

CONCLUSIONRAD51-G135C homozygous mutant and XRCC3-C241T heterozygous mutation significantly increase the risk of the AML onset, which can provide more predictive value for incidence of AML.

DNA-Binding Proteins ; Heterozygote ; Homozygote ; Humans ; Leukemia, Myeloid, Acute ; Polymorphism, Single Nucleotide ; Rad51 Recombinase

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 genomic instability may lead to an initiation of cancer in many organisms. Homologous recombination repair (HRR) is vital in maintaining cellular genomic stability. RAD51 associated protein 1 (RAD51AP1), which plays a crucial role in HRR and primarily participates in forming D-loop, was reported as an essential protein for maintaining cellular genomic stability. However, recent studies showed that RAD51AP1 was significantly overexpressed in various cancer types and correlated with poor prognosis. These results suggested that RAD51AP1 may play a significant pro-cancer effect in multiple cancers. The underlying mechanism is still unclear. Cancer stemness-maintaining effects of RAD51AP1 might be considered as the most reliable mechanism. Meanwhile, RAD51AP1 also promoted resistance to radiation therapy and chemotherapy in many cancers. Thus, researches focused on RAD51AP1, and its regulatory molecules may provide new targets for overcoming cancer progression and treatment resistance. Here, we reviewed the latest research on RAD51AP1 in cancers and summarized its differential expression and prognostic implications. In this review, we also outlined the potential mechanisms of its pro-cancer and drug resistance-promoting effects to provide several potential directions for further research.
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Humans ; DNA-Binding Proteins/metabolism* ; RNA-Binding Proteins/metabolism* ; Lung Neoplasms ; DNA Repair ; Genomic Instability ; Rad51 Recombinase/metabolism*

Ovarian carcinoma is the most lethal gynecologic malignancy. Resistance to platinum is considered the major problem affecting prognosis. Our recent study established that microRNA-506 (miR-506) expression was closely associated with progression-free survival and overall survival in two independent patient cohorts totaling 598 epithelial ovarian cancer cases. Further functional study demonstrated that miR-506 could augment the response to cisplatin and olaparib through targeting RAD51 and suppressing homologous recombination in a panel of ovarian cancer cell lines. Systemic delivery of miR-506 in an orthotopic ovarian cancer mouse model significantly augmented the cisplatin response, thus recapitulating the clinical observation. Therefore, miR-506 plays a functionally important role in homologous recombination and has important therapeutic value for sensitizing cancer cells to chemotherapy, especially in chemo-resistant patients with attenuated expression of miR-506.
Animals ; Antineoplastic Agents ; Cell Line, Tumor ; Cisplatin ; Disease-Free Survival ; Drug Resistance, Neoplasm ; Drug Therapy, Combination ; Female ; Homologous Recombination ; Humans ; Mice ; MicroRNAs ; Ovarian Neoplasms ; Piperazines ; Prognosis ; Rad51 Recombinase

OBJECTIVEThe functional characters of MCF7 and HCC1937 cell lines were compared through the activity of BRCA1 and p53 following DNA damage in order to provide more research evidence for the related studies in both breast cancer cell lines.

METHODSThe protein level of BRCA1 and p53 in two breast cancer cell lines and the protein level of BRCA1 in MCF7, HCC1937 and HCC1937 wtBRCA1 breast cancer cell lines treated with 10Gy after 1 h, 4 h or 8 h were detected by western blotting analysis. The distribution and foci formation of BRCA1 in the cells were observed through immunostaining assay and the percentage of BRCA1 or Rad51 foci formation after ionizing radiation was calculated. Cell cycle profiling was analyzed using flow cytometry.

RESULTSMost of BRCA1 and p53 localized in nucleus, and both proteins responded to DNA damage in MCF7 cells. In MCF7 cells,BRCA1 and Rad51 foci formation respectively increased to (59.40 ± 3.66)% from (11.80 ± 3.51)% (t = 16.26, P < 0.05) and (73.90 ± 8.66) % from (16.70 ± 3.76) % (t = 10.49, P < 0.05) after 10 Gy 8 h ; p53 and p21 protein level was further separately induced and enhanced to (82.54 ± 1.04) from (23.75 ± 0.51) (t = 87.90, P < 0.05) and (90.95 ± 1.13) from (50.19 ± 0.89) ( t = 49.11, P < 0.05) after 10 Gy 8 h; and the cells were accumulated in G1 phase. In contrast to MCF7, in HCC1937 cell line, both of BRCA1 and p53 were defective in nucleus since both proteins were mutated; in response to DNA damage, BRCA1 foci formation was not found, p53 and p21 was not induced; there was no cell accumulation in both of G1-S and G2-M phases. However, after complementation of wild-type BRCA1 in HCC1937 cells, DNA damage-induced Rad51 foci formation increased to (61.70 ± 4.03) % from (6.22 ± 2.27) % (t = 20.78, P < 0.05) and accumulation of cells in G2-M phase was also restored after 10 Gy 8h , which was similar to that of in MCF7 cells.

CONCLUSIONSWe have identified that BRCA1 and p53 have dramatically different functions in MCF7 and HCC1937 cell lines in response to DNA damage.

Cell Cycle ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; DNA Damage ; Humans ; MCF-7 Cells ; Rad51 Recombinase ; Radiation, Ionizing ; Tumor Suppressor Protein p53 ; Ubiquitin-Protein Ligases

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

OBJECTIVE: To investigate the expression and clinical significance of RAD51 in laryngocarcinoma. METHOD: The expression of RAD51 in laryngocarcinoma and polyp of vocal cord tissues were determined by immunohistochemical staining. The results were analyzed and compared with the clinical stage, lymph node metastasis and pathologic grade. RESULT: (1) The expression of RAD51 in laryngocarcinoma group was extremely stronger than that in polyp of vocal cord group (P < 0.01). (2) There was significant difference for RAD51 expression in cancer cells between earlier clinical stage group and advanced clinical stage group (P < 0.01). (3) There was significant difference for RAD51 expression in different pathologic grades (P < 0.05). (4) There was also significant difference for RAD51 expression between groups with and without lymph node metastasis. CONCLUSION RAD51 may play a critical role in tumorigenesis of laryngocarcinoma. RAD51 may be a potential marker for clinical diagnosis and treatment of Laryngocarcinoma. It may be significant in predicting clinical stage, pathologic grade and metastasis.
Female ; Humans ; Laryngeal Neoplasms ; metabolism ; pathology ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Staging ; Polyps ; metabolism ; pathology ; Prognosis ; Rad51 Recombinase ; metabolism ; Vocal Cords ; pathology

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

BACKGROUNDOvarian serous adenocarcinoma can be divided into low- and high-grade tumors, which exhibit substantial differences in pathogenesis, clinicopathology, and prognosis. This study aimed to investigate the differences in the PH domain leucine-rich repeat protein phosphatase (PHLPP), forkhead homeobox type O 3a (FoxO3a), and RAD51 protein expressions, and their associations with prognosis in patients with low- and high-grade ovarian serous adenocarcinomas.

METHODSThe PHLPP, FoxO3a, and RAD51 protein expressions were examined in 94 high- and 26 low-grade ovarian serous adenocarcinomas by immunohistochemistry. The differences in expression and their relationships with pathological features and prognosis were analyzed.

RESULTSIn high-grade serous adenocarcinomas, the positive rates of PHLPP and FoxO3a were 24.5% and 26.6%, while in low-grade tumors, they were 23.1% and 26.9%, respectively (P < 0.05 vs. the control specimens; low- vs. high-grade: P > 0.05). The positive rates of RAD51 were 70.2% and 65.4% in high- and low-grade serous adenocarcinomas, respectively (P < 0.05 vs. the control specimens; low- vs. high-grade: P > 0.05). Meanwhile, in high-grade tumors, Stage III/IV tumors and lymph node and omental metastases were significantly associated with lower PHLPP and FoxO3a and higher RAD51 expression. The 5-year survival rates of patients with PHLPP- and FoxO3a-positive high-grade tumors (43.5% and 36.0%) were significantly higher than in patients with PHLPP-negative tumors (5.6% and 7.2%, respectively; P< 0.05). Similarly, the 5-year survival rate of RAD51-positive patients (3.0%) was significantly lower than in negative patients (42.9%; P< 0.05). In low-grade tumors, the PHLPP, FoxO3a, and RAD51 expressions were not significantly correlated with lymph node metastasis, omental metastasis, Federation of Gynecology and Obstetrics stage, or prognosis.

CONCLUSIONSAbnormal PHLPP, FoxO3a, and RAD51 protein expressions may be involved in the development of high- and low-grade ovarian serous adenocarcinomas, suggesting common molecular pathways. Decreased PHLPP and FoxO3a and increased RAD51 protein expression may be important molecular markers for poor prognosis, and RAD51 may be an independent prognosis factor, of high-grade, but not low-grade, ovarian serous adenocarcinomas.

Adult ; Aged ; Biomarkers, Tumor ; metabolism ; Cystadenocarcinoma, Serous ; metabolism ; pathology ; Female ; Forkhead Box Protein O3 ; metabolism ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Middle Aged ; Neoplasm Staging ; Nuclear Proteins ; metabolism ; Ovarian Neoplasms ; metabolism ; pathology ; Phosphoprotein Phosphatases ; metabolism ; Prognosis ; Rad51 Recombinase ; metabolism