Analysis of DNA damage repair pathway genes as a predictive biomarker for HAIC in hepatocellular carcinoma.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e16159-e16159
Author(s):  
Qicong Mai ◽  
Zhiqiang Mo ◽  
Jian He ◽  
Tingting Chen ◽  
Mengli Huang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Dna Damage ◽  
Survival Analysis ◽  
Homologous Recombination ◽  
Mutation Frequency ◽  
Predictive Biomarker ◽  
Wild Type ◽  
Type Group ◽  
Whole Exome ◽  
Chinese Cohort

e16159 Background: Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality worldwide.Hepatic arterial infusion chemotherapy (HAIC) with oxaliplatin, fluorouracil, and leucovorin (FOLFOX) is one of the effective treatment for advanced HCC patients. DNA damage repaired (DDR) pathway has been widely researched in many cancers recent years, which was a promising predictive biomarker for the response to platinum-based chemotherapy and Immunotherapy. But the DDR characteristics of different subset pathways in HCC, and its correlation with HAIC efficacy were unknown. Methods: Whole exome sequencing (WES) data of 366 HCC patients was obtained from the Cancer Genome Altas (TCGA). Next generation sequencing (NGS, panel on 381/733-gene) was performed on FFPE tumor samples from 2092 Chinese HCC patients (Chinese cohort). Germ-line or somatic mutations of 32 DDR pathway genes (including Mismatch Repair and Homologous Recombination) were classified as DDR gene mutations. TMB was defined as total number of somatic non-synonymous mutations in coding region. Whole exome sequencing (WES) data and clinical data of 21 HCC advanced patients treated with HAIC were obtained to survival analysis. Results: In total, 59.84% (219/366) of HCC patients in TCGA harboring DDR mutation and 67.38% (1316/2092) in Chinese cohort. In Chinese HCC cohort, the mean TMB level of DDR mutant group was significant higher than wild-type group (mean TMB, mutation vs wild-type = 8.12 vs 6.42 Muts/Mb, P < 0.0001). The top three mutation frequency DDR genes were BRCA2 (17%), ATM (13%) and BARD1 (12%), respectively. The highest mutation frequency DDR subset pathways were Fanconi anemia (FA, 44.14%, 862/2092), homologous recombination repair (HRR, 38.71%, 756/2092) and check point factors (CHP, 17.31%, 338/2092) come in second and third, respectively. Next we compared the TMB level between different DDR subset pathways, the mutant of nucleotide excision repair (NER) pathway harbored the highest medium TMB level (7.26 Muts/Mb). The survival analysis was performed on HCC patients treated with HAIC with FOLFOX. There was no difference in clinical baseline information between DDR mutation group (n = 6) and wild-type group (n = 15). The progression-free survival (PFS) of DDR mutation group were significantly longer than wild-type group (median PFS, mutation vs. wild-type = 8.9 vs. 4.5 months; HR 0.34[95% CI 0.13-0.85]; P = 0.0349), and an extending trend on overall survival (OS) without significant difference (median OS, 15.7 vs 8.9 months; HR 0.37[95% CI 0.13-1.00]; P = 0.0921). Conclusions: The DDR pathways was associated with higher TMB level. Preliminary data from clinical cohorts suggested better treatment outcomes of HAIC with FOLFOX in DDR mutation HCC patients.

Molecular characteristics of patients with resectable hepatocellular carcinoma.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e16140-e16140
Author(s):  
Daobing Zeng ◽  
Menglong Wang ◽  
Jushan Wu ◽  
Dongdong Lin ◽  
Qingliang Guo ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Homologous Recombination ◽  
Signaling Pathway ◽  
Parp Inhibitors ◽  
Genetic Alterations ◽  
Immune Checkpoint Blockade ◽  
Molecular Characteristics ◽  
Whole Exome ◽  
Targeted Treatments ◽  
Chinese Cohort

e16140 Background: Hepatocellular carcinoma (HCC) is one of the most common malignancies and leading cause of cancer deaths worldwide. Biomarkers contribute to predict the response of targeted treatments and immunotherapy. Therapy directed toward homologous recombination deficiency (HRD) is now approved in ovarian and breast cancer, but the pattern of HRD is not clear in HCC. The HRD phenotype has been defined as the presence of a non-silent somatic mutation in homologous recombination-related (HRR) genes. Thus, we aimed to analyze the molecular characteristics of resectable HCC, including HRR genes. Methods: Matched tumor/normal DNA from resectable HCC patients (N = 53) were analyzed by whole exome sequencing (WES) or Acornmed panel with 808 cancer-related genes. Results: Overall, 94.3% (50/53) patients exhibited genetic alterations. TP53, ARID1A, PTEN and NBPF1 were the most commonly mutated genes in resectable HCC. In addtion, 35.9% patinets harbored at least one HRR genes mutation. The frequently mutated genes were BRCA2 (4.4%), BRCA1(4.0%), ATM (3.9 %), and RAD50 (3.8%). Interesting, frequency of HRR genes mutation in the Chinese cohort was higher than that in TCGA (35.9 % vs 20.9%). Analysis of carcinogenic pathways shown that ERBB and PI3K-AKT signaling pathway were the common signaling pathway. In resectable HCC, 32.08% (17/53) patients disclosed high TMB (highest 25%). Further analysis found that PTEN mutations were remarkably associated with low TMB (p < 0.05). Conclusions: This study contributes to understand the molecular characteristics of patients with resectable HCC, which will be useful to guide personalized therapy and promote the clinical management in this population. Furthermore, the study suggested that it is feasibility for resectable HCC patients received PARP inhibitors, DNA-damaging chemotherapies, and immune checkpoint blockade therapy.

scholarly journals Sml1 Inhibits the DNA Repair Activity of Rev1 in Saccharomyces cerevisiae during Oxidative Stress

2020 ◽  
Vol 86 (7) ◽  
Author(s):  
Rui Yao ◽  
Pei Zhou ◽  
Chengjin Wu ◽  
Liming Liu ◽  
Jing Wu
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Dna Damage ◽  
Survival Rate ◽  
Type Strain ◽  
Mutation Frequency ◽  
Wild Type Strain ◽  
Yeast Cells ◽  
Wild Type ◽  
Content Type

ABSTRACT In Saccharomyces cerevisiae, Y family DNA polymerase Rev1 is involved in the repair of DNA damage by translesion DNA synthesis (TLS). In the current study, to elucidate the role of Rev1 in oxidative stress-induced DNA damage in S. cerevisiae, REV1 was deleted and overexpressed; transcriptome analysis of these mutants along with the wild-type strain was performed to screen potential genes that could be associated with REV1 during response to DNA damage. When the yeast cells were treated with 2 mM H2O2, the deletion of REV1 resulted in a 1.5- and 2.8-fold decrease in the survival rate and mutation frequency, respectively, whereas overexpression of REV1 increased the survival rate and mutation frequency by 1.1- and 2.9-fold, respectively, compared to the survival rate and mutation frequency of the wild-type strain. Transcriptome and phenotypic analyses identified that Sml1 aggravated oxidative stress in the yeast cells by inhibiting the activity of Rev1. This inhibition was due to the physical interaction between the BRCA1 C terminus (BRCT) domain of Rev1 and amino acid residues 36 to 70 of Sml1; the cell survival rate and mutation frequency increased by 1.8- and 3.1-fold, respectively, when this interaction was blocked. We also found that Sml1 inhibited Rev1 phosphorylation under oxidative stress and that deletion of SML1 increased the phosphorylation of Rev1 by 46%, whereas overexpression of SML1 reduced phosphorylation of Rev1. Overall, these findings demonstrate that Sml1 could be a novel regulator that mediates Rev1 dephosphorylation to inhibit its activity during oxidative stress. IMPORTANCE Rev1 was critical for cell growth in S. cerevisiae, and the deletion of REV1 caused a severe growth defect in cells exposed to oxidative stress (2 mM H2O2). Furthermore, we found that Sml1 physically interacted with Rev1 and inhibited Rev1 phosphorylation, thereby inhibiting Rev1 DNA antioxidant activity. These findings indicate that Sml1 could be a novel regulator for Rev1 in response to DNA damage by oxidative stress.

Mutation profiles in circulating tumor DNA (ctDNA) to predict the efficacy of sorafenib treatment in patients with advanced hepatocellular carcinoma (HCC).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e15648-e15648
Author(s):  
Ping Yang ◽  
Guanghui Ji ◽  
Qionghui Jiang ◽  
Zejun Lu ◽  
Yao Yu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Gene Mutation ◽  
Therapeutic Efficacy ◽  
Genomic Dna ◽  
Mutation Frequency ◽  
Advanced Hepatocellular Carcinoma ◽  
Sequencing Analysis ◽  
Wild Type ◽  
Blood Samples ◽  
Mutation Type

e15648 Background: To find biomarkers from blood samples through ctDNA and leucocyte genomic DNA sequencing to predict the efficacy of sorafenib. Methods: CtDNA and leucocyte genomic DNA were extracted from patients with advanced hepatocellular carcinoma for sequencing analysis before and after targeted therapy with sorafenib. Mutation profiles were obtained by deep sequencing of 620 selected genes for further bioinformatics analysis. Gene mutation frequency and status were further integrated with clinical data to dynamically monitor and predict the efficacy of sorafenib. Results: Twelve patients with advanced hepatocellular carcinoma admitted to our hospital from March 2017 to September 2018 were enrolled. A total of 27 blood samples were collected for further analysis. The results showed that there were significant differences in BRD4 and FANCG gene mutation abundance between therapeutic effect group and poor effect group (p = 0.014). The mutations of BRD4, FANCG and TP53 were associated with shorter PFS (BRD4 mutation type vs wild type: 12 weeks vs 32 weeks, p = 0.0011; FANCG mutation type vs wild type: 16 weeks vs 32 weeks, p = 0.0103; TP53 mutation type vs wild type: 8 weeks vs 32 weeks, p = 0.0095). Furthermore, we found another 19 genes (SDHA, OTUD7A, TMPRSS2, NAV3, AKT1, EIF2S2, DICER1, MAP3K1, RAD9A, TCF3, IRS1, PIK3C2G, CTCF, TSHZ2, ITPKB, KDM5C, STAG2, AMER1, CDC27) associated with therapeutic efficacy, and dynamic changes of these 19 genes mutation alleys could predict therapeutic efficacy. Conclusions: Our results showed that mutations in ctDNA could predict the efficacy and prognosis of sorafenib for advanced hepatocellular carcinoma, and that dynamic monitoring of mutation frequency in ctDNA of peripheral blood samples could be an additional method to monitor therapeutic efficacy of sorafenib. The clinical significance of the mutations of BRD4, FANCG, TP53 and another 19 genes we found needs to be confirmed on a larger scale.

scholarly journals A conserved histone H3-H4 interface regulates DNA damage tolerance and homologous recombination during the recovery from replication stress

2021 ◽  
Author(s):  
Masafumi Hayashi ◽  
Kenji Keyamura ◽  
Asami Yoshida ◽  
Mariko Ariyoshi ◽  
Genki Akanuma ◽  
...  
Keyword(s):  
Dna Damage ◽  
Homologous Recombination ◽  
Damage Tolerance ◽  
Histone H3 ◽  
Wild Type ◽  
Dna Damage Tolerance ◽  
Damage Resistance ◽  
Replication Arrest ◽  
Induced Mutagenesis ◽  
Phase Progression

In eukaryotes, genomic DNA is packaged into nucleosomes, which are the basal components coordinating both the structures and functions of chromatin. Here we screened a collection of mutation for histone H3/H4 mutants in Saccharomyces cerevisiae that affect the DNA damage sensitivity of DNA damage tolerance (DDT)-deficient cells. We identified a class of histone H3/H4 mutations that suppress MMS sensitivity of DDT-deficient cells (hereafter we refer to as the histone SDD mutations), which likely cluster on a specific H3-H4 interface of the nucleosomes. The histone SDD mutations did not suppress the MMS sensitivity of DDT-deficient cells in the absence of Rad51, indicating that homologous recombination (HR) is responsible for DNA damage resistance. Furthermore, the histone SDD mutants showed reduced levels of PCNA ubiquitination after exposure to MMS or UV irradiation, consistent with a decreased MMS-induced mutagenesis relative to wild-type cells. We also found that histone SDD mutants lacking the INO80 chromatin remodeler impair HR-dependent recovery from MMS-induced replication arrest, resulting in defective S-phase progression and increased Rad52 foci. Taken together, our data provide novel insights into nucleosome functions, which link INO80-dependent chromatin remodeling to the regulation of DDT and HR during the recovery from replication blockage.

Phosphorylation of FANCA on S1449 Is Important for Fanconi Anemia (FA) Pathway Function.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 186-186
Author(s):  
Natalie B. Collins ◽  
Andrei Tomashevski ◽  
Gary M. Kupfer
Keyword(s):  
Dna Damage ◽  
Homologous Recombination ◽  
Dna Damage Response ◽  
Fanconi Anemia ◽  
Phosphorylation Site ◽  
Site Directed Mutagenesis ◽  
Wild Type ◽  
Damage Response ◽  
And Function ◽  
Mutant Cells

Abstract Previous work in our lab and others has shown that the Fanconi anemia proteins, FANCG and FANCA, are phosphoproteins. FANCG is phosphorylated at mitosis, and these phosphorylations are required for proper exit from chromatin at mitosis. FANCG is also phosphorylated after DNA damage, with the phosphorylation site required for wild-type sensitivity to DNA damaging agents. FANCA is also phosphorylated after DNA damage and localized to chromatin, but the site and significance of this phosphorylation were previously unknown. Mass spectrometry of FANCA revealed one phosphopeptide with phosphorylation on serine 1449. Site-directed mutagenesis of this residue to alanine (S1449A) abolished a slower mobility form of FANCA seen after MMC treatment. Furthermore, the S1449A mutant failed to completely correct the MMC hypersensitivity of FA-A mutant cells. S1449A mutant cells displayed lower than wild-type levels of FANCD2 monoubiquitination following DNA damage, and an increased number of gross chromosomal aberrations were seen in metaphase spreads from S1449A mutant cells when compared to wild type cells. Using a GFP reporter substrate to measure homologous recombination, cells expressing the S1449A FANCA failed to completely correct the homologous recombination defect seen in FA cells. Taken together, cells expressing FANCA S1449A display a variety of FA-associated phenotypes, suggesting that the phosphorylation of S1449 is a functionally significant event. The DNA damage response in human cells is, in large part, coordinated by phosphorylation events initiated by apical kinases ATM and ATR. S1449 is found in a consensus ATM site, therefore studies are underway to determine if ATM or ATR is the kinase responsible for FANCA phosphorylation at S1449. Phosphorylation is a crucial process in transducing the DNA damage response, and phosphorylation of FA proteins appears critical to both localization and function of the proteins. Understanding how phosphorylation marks are placed on FANCA will give insight into the role of FANCA in the DNA damage response.

scholarly journals Loss of BCL-3 sensitises colorectal cancer cells to DNA damage, revealing a role for BCL-3 in double strand break repair by homologous recombination

2021 ◽  
Author(s):  
Christopher Parker ◽  
Adam Christian Chambers ◽  
Dustin Flanagan ◽  
Tracey J Collard ◽  
Greg Ngo ◽  
...  
Keyword(s):  
Dna Damage ◽  
Homologous Recombination ◽  
Cellular Response ◽  
Parp Inhibitor ◽  
Strand Break ◽  
Double Strand Break ◽  
Parp Inhibition ◽  
Adjuvant Chemoradiotherapy ◽  
Wild Type ◽  
Γ Irradiation

Objective: The proto-oncogene BCL-3 is upregulated in a subset of colorectal cancers (CRC) and increased expression of the gene correlates with poor patient prognosis. The aim is to investigate whether inhibiting BCL-3 can increase the response to DNA damage in CRC.Design: The function of BCL-3 in DNA damage response was studied in vitro using siRNA and CRISPR-Cas9 genome editing and in vivo using Bcl3-/- mice. DNA damage induced by γ-irradiation and/or cisplatin was quantified using H2AX and RAD51 foci, repair pathways investigated using HR/NHEJ assays and treatment with the PARP inhibitor olaparib. Result: Suppression of BCL-3 increases double strand break number and decreases homologous recombination in CRC cells, supported by reduced RAD51 foci number and increased sensitivity to PARP inhibition. Importantly, a similar phenotype is seen in Bcl3-/-mice, where the intestinal crypts of these mice exhibit sensitivity to DNA damage and a greater number of double strand breaks compared to wild type mice. FurthermoreApc.Kras-mutant x Bcl3-/- mice exhibit increased DNA damage and reduced RAD51+ cells compared to their wild type counterparts when treated with cisplatin. Conclusion: This work identifies BCL-3 as a regulator of the cellular response to DNA damage and suggests that elevated BCL-3 expression could increase resistance of tumour cells to DNA damaging agents including radiotherapy. These findings offer a rationale for targeting BCL-3 in CRC as an adjuvant to conventional therapies and suggest that BCL-3 expression in tumours could be a useful biomarker in stratification of rectal cancer patients for neo-adjuvant chemoradiotherapy.

scholarly journals Homologous and Homeologous Intermolecular Gene Conversion Are Not Differentially Affected by Mutations in the DNA Damage or the Mismatch Repair Genes RAD1, RAD50, RAD51, RAD52, RAD54, PMS1 and MSH2

Genetics ◽  
1996 ◽  
Vol 143 (2) ◽  
pp. 755-767 ◽  
Author(s):  
Gregory Porter ◽  
Jim Westmoreland ◽  
Scott Priebe ◽  
Michael A Resnick
Keyword(s):  
Dna Damage ◽  
Homologous Recombination ◽  
Gene Conversion ◽  
Mismatch Repair ◽  
Dna Damage Repair ◽  
Single Copy ◽  
Wild Type ◽  
Recombination Rates ◽  
Damage Repair ◽  
In The Wild

Abstract Mismatch repair (MMR) genes or genes involved in both DNA damage repair and homologous recombination might affect homeologous us. homologous recombination differentially. Spontaneous mitotic gene conversion between a chromosome and a homologous or homeologous donor sequence (14% diverged) on a single copy plasmid was examined in wild-type Saccharomyces cerevisiae strains and in MMR or DNA damage repair mutants. Homologous recombination in rad51, rad52 and rad54 mutants was considerably reduced, while there was little effect of radl, rad50, pms1 and msh2 null mutations. DNA divergence resulted in no differential effect on recombination rates in the wild type or the mutants; there was only a five- to 10-fold reduction in homeologous relative to homologous recombination regardless of background. Since DNA divergence is known to affect recombination in some systems, we propose that differences in the role of MMR depends on the mode of recombination and/or the level of divergence. Based on analysis of the recombination breakpoints, there is a minimum of three homologous bases required at a recombination junction. A comparison of Rad+  vs. rad52 strains revealed that while all conversion tracts are continuous, elimination of RAD52 leads to the appearance of a novel class of very short conversion tracts.

scholarly journals Growth arrest DNA damage-inducible gene 45 gamma expression as a prognostic and predictive biomarker in hepatocellular carcinoma

Oncotarget ◽  
2015 ◽  
Vol 6 (29) ◽  
pp. 27953-27965 ◽  
Author(s):  
Da-Liang Ou ◽  
Song-Kun Shyue ◽  
Liang-In Lin ◽  
Zi-Rui Feng ◽  
Jun-Yang Liou ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Dna Damage ◽  
Growth Arrest ◽  
Predictive Biomarker ◽  
Inducible Gene

Relationship between DICER1 mutations and immunotherapy biomarkers in solid tumors.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2603-2603
Author(s):  
Jie Gao ◽  
Xia You ◽  
Taiyan Guo ◽  
Qin Zhang ◽  
Qianqian Duan ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Colon Adenocarcinoma ◽  
Chinese Patients ◽  
Wild Type ◽  
Type Group ◽  
Chinese Cohort ◽  
Mutation Ratio ◽  
Mutation Group ◽  
Dicer1 Syndrome ◽  
Pan Cancer

2603 Background: Dicer1 functions as a tumor suppressor in mouse models. In humans, somatic mutations are associated with many cancers in adults, and patients with DICER1 syndrome with DICER1 germline mutations are susceptible to childhood cancers. DICER1 is the core caner-intrinsic CTL-evasion gene, especially positive correlate with innate anti-PD-1 resistance signature or IPRES signature and hERV expression which involved in sensitivity and resistance to ICIs. Nevertheless, the association between mutations in DICER1 and the Chinese patients, the relationship between DICER1 mutations with immunotherapy biomarkers are unknown. Methods: NGS and clinical data were collected from 10953 Western pan-cancer patients (TCGA cohort). A 539-gene panel targeted sequencing assay was performed on FFPE tumor samples from 3514 Chinese pan-cancer patients (Chinese cohort). Both DICER1 mutation ratio and TMB were calculated on the two cohorts following the same criteria.DNA NGS testing (MSI-high vs low/stable (MSS)) in Chinese cohort were included. NGS data of 3514 patients who also detected PD-L1 expression from Chinese clinical dataset were analyzed to explore the association with mutation and PD-L1. The survival information was collected from 1661 pan-cancer patients to analyze the association between DICER1 mutation and efficacy of immunotherapy (MSKCC cohort). Results: In total, 2.91% (319/10953) patients in TCGA harbored DICER1 mutation; in the Chinese cohort, the DICER1 mutation ratio (2.67%, 94/3514) was similar to TCGA. The top 5 mutant DICER1-associated cancer types in Chinese cohort were lung cancer, colon adenocarcinoma, liver cancer, uterine corpus endometrial carcinoma, melanoma. In both cohorts, TMB level of mutation group was significantly higher than wild-type group (p < 0.001). The ration of mutation group in MSI-H (50%) and MSI-L (23.53%) was significantly higher than wild-type group in Chinese cohort (2.17%) (p < 0.001). In addition, the ratio of PD-L1 positive expression (≥1%) in mutation group (48.94%, 46/48) was significantly higher than wild-type in Chinese cohort (38.48%,1316/2104) (p < 0.05). The survival probability of mutation group was significantly longer than wild-type group in immunotherapy. Conclusions: The results indicated that DICER1 mutation was associated with a higher TMB, MSI-H and PD-L1 expression level in Chinese patients. Patients with DICER1 mutations may benefit more from ICIs.

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