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Radiotherapy is widely used in the management of advanced colorectal cancer (CRC). However, the clinical efficacy is limited by the safe irradiated dose. Sensitizing tumor cells to radiotherapy via interrupting DNA repair is a promising approach to conquering the limitation. The BRCA1-BARD1 complex has been demonstrated to play a critical role in homologous recombination (HR) DSB repair, and its functions may be affected by HERC2 or BAP1. Accumulated evidence illustrates that the ubiquitination-deubiquitination balance is involved in these processes; however, the precise mechanism for the cross-talk among these proteins in HR repair following radiation hasn't been defined. Through activity-based profiling, we identified PT33 as an active entity for HR repair suppression. Subsequently, we revealed that BAP1 serves as a novel molecular target of PT33 via a CRISPR-based deubiquitinase screen. Mechanistically, pharmacological covalent inhibition of BAP1 with PT33 recruits HERC2 to compete with BARD1 for BRCA1 interaction, interrupting HR repair. Consequently, PT33 treatment can substantially enhance the sensitivity of CRC cells to radiotherapy in vitro and in vivo. Overall, these findings provide a mechanistic basis for PT33-induced HR suppression and may guide an effective strategy to improve therapeutic gain.
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Objective To investigate the relationship between single nucleotide polymorphism (SNP) of BARD 1 gene and BRCA1 gene in epithelial ovarian cancer (EOC).Methods Nineteen EOC patients with BRCA1 gene mutation and 50 EOC cases without BRCA1 gene mutation between January 2016 and October 2016 were collected,and all EOC were diagnosed by pathological method.BARD1 gene variants were detected by next generation sequencing (NGS).The SNP of BARD1 gene was analyzed by Pearson linear correlation.Logistic regression analysis was used to research the clinicopathologic features and BRCA1 gene mutation associated with BARD1 gene SNP.Pearson's chi-square test was used to analyze the association between BARD1 gene Val507Met,Arg378Ser and Pro24Ser with different clinicopathologic features and BRCA1 gene mutation risk.Results (1) Eight BARD1 gene variants were found in 69 ovarian cancer patients,in which Val507Met,Arg378Ser and Pro24Ser were common variants,and the rate of mutation were all 54％ (37/69).(2) There was a significant linear correlation among Val507Met,Arg378Ser and Pro24Ser (all P＜0.01).(3) Obvious differences were found in Val507Met,Arg378Ser and Pro24Ser of BARD1 gene between BRCA1+ and BRCA1 (all P＜0.05).(4) No differences were found between BARD1 gene Val507Met,Arg378Ser and Pro24Ser and the clinicopathologic features (all P＞0.05),while obvious differences were found in BRCA1 gene mutation compared to the controls group.The risk of BRCA1 mutation in Val507Met and Arg378Ser were more evident in subjects with negative family history,positive menopause history,negative tubal ligation,onset age (≤60 years old) and sensitivity to platinum-based chemotherapy in EOC (all P＜0.05),while Pro24Ser was only more evident in positive menopause history of EOC (P＜0.05).Conclusions BARD1 Val507Met,Arg378Ser and Pro24Ser are the common genotypes,which are associated with BRCA1 mutation in EOC.The family history,menopause history,tubal ligation,onset age and sensitivity to platinum-based chemotherapy have effects on BARD1 SNP in the risk of BRCA1 gene mutation.
ABSTRACT
BRCA1-associated RING domain 1(BARD1) is composed with ring finger,ankyrin repeats and BRCT (BRCA1 C-terminus) domain.The special structure is involved in many essential biological processes such as DNA repair,cell survival and apoptosis,proteasome dependent protein degradation and so on.The abnormal expression of BARD1 is closely related with the occurrence and progression of carcinoma.Aberrant splice variants of BARD1 are very potential tumor markers for cancer diagnosis.
ABSTRACT
BARD1 (BRCA1 associated RING domain 1) foi identificada originalmente como uma proteína de interação de BRCA1 (breast cancer 1, early onset) através de ensaio de dois híbridos em levedura (Y2H). Foi descrito que a formação do heterodímero BRCA1/BARD1 éessencial para que BRCA1 exerça sua função supressora de tumor. Ambas as proteínas interagem através de seus domínios RING N-terminais para formar o heterodímero BRCA1/BARD1 com atividade E3 ubiquina ligase, o que constitui a principal atividade catalítica deste complexo. A porção C-terminal de BRCA1 contém dois domínios BRCT em tandem (tBRCT), característicos de uma grande família de proteínas envolvidas no controle da estabilidade genômica. Esses domínios tBRCT medeiam a associação com uma plêiade de proteínas com papel importante no controle do reparo de dano ao DNA (RDD), transcrição gênica e ciclo celular. A fim de identificar novas proteínas de interação com BARD1 foi realizado Y2H utilizando o tBRCT (554-777aa) de BARD1 e uma biblioteca de cDNA de testículo humano. Como resultado, foi identificado, dentre outras proteínas, o cDNA que codifica para a porção C-terminal de BCCIP (BRCA2 and CDKN1A Interacting Protein) (240-322aa). BCCIP foi descrito por seu envolvimento em vias de RDD e controle do ciclo celular. BCCIP interage com BRCA2 e ambas são importantes para a formação defoco de RAD51 após o dano por radiação ionizante. BCCIP interage com p21, potencializando a inibição de CDK2, além de regular a atividade transcricional de p53 na região promotora de p21...
BARD1 (BRCA1 associated RING domain 1) was originally identified in a yeast-two-hybrid (Y2H) screen as a binding partner of BRCA1 (breast cancer 1, early onset). The functional heterodimer BRCA1/BARD1 is required for several of the cellular and tumor-suppressorfunctions of BRCA1. Both proteins interact through the N-terminal RING domain to form aheterodimeric E3 ubiquitin ligase that constitutes the major catalytic activity of the BRCA1-BARD1 complex. The carboxy terminus of BRCA1 is highly acidic and contains two tandemBRCA1 C-terminal (tBRCT) domains, which are characteristic of members of a large familyof proteins involved in genome stability. These domains are protein-protein interactingregions that mediate the association with a number of other proteins with a role in DNAreplication, DNA damage repair (DDR) pathway, transcription and cell cycle control. In orderto identify putative interaction-proteins with BARD1 C-terminal region our group performed aY2H assay using BARD1 tBRCT (aa 554-777) to screen a human testis cDNA library. Asresult, we identified, among other hits, a cDNA coding for BCCIP (BRCA2 and CDKN1 Ainteracting protein) C-terminal region, residues 240-322. BCCIP is known for its involvementin DDR and cell cycle control. BCCIP interacts with BRCA2, and both proteins are importantfor RAD51 focus formation after ionizing radiation and homologous recombination (HR)repair of double-strand-breaks (DSBs). BCCIP enhances the p21 suppression activitytowards CDK2 and its downregulation reduces p21 expression by abrogating p53transcription activity. The aim of this study is to analyze the role of BCCIP in the DDRpathway. We confirmed the BARD1/BCCIP interaction by pull-down and co-immunoprecipitation (co-IP) analyzes of ectopically expressed BARD1 and BCCIP...
Subject(s)
Humans , Male , Female , Breast Neoplasms , DNA Damage , DNA Repair , Genes, BRCA1 , BRCA1 ProteinABSTRACT
OBJECTIVE: The aim of this study was to identify interaction between causative factors of cervical cancer and BARD-1 (BRCA1 associated ring domain-1) polymorphism on cervical carcinogenesis in Korean women. METHODS: We evaluated 1,347 patients composed of women who had cervical cancer (n=337) and cervical intraepithelial neoplasia (n=308) and normal control healthy women (n=702) from October 2000 until November 2001. The single nucleotide polymorphisms (SNPs) of BARD-1 were evaluated from extracted DNA of peripheral blood with automatic DNA sequencer. The difference of each SNP between normal controls and patients was evaluated in the adjusted environmental background. RESULTS: In environmental aspect, the cervical cancer increased in the women who had the lower level of education, smoking history, the younger age of the first sexual intercourse, and the more child-bearing . The women who had BARD V507M (Arg/Arg) showed 1.6 fold increased risk in cervical cancer than the women who had BARD V507M (G/G), (G/A)(p=0.0433). And the risk increased with BARD R378S (C/C) among who have environmental risk factors compared with BARD R378S (G/G), (G/C) allele positive who have no environmental risk factors. CONCLUSION: We found that the level of education, the age at first intercourse, and the number of children were the independent risk factors in cervical carcinogenesis. The specific combination of BARD-1 and gene-environmental interactions were significantly noted in the cervical carcinogenesis in Korean women.