Genomic determinants of sensitivity to bipolar androgen therapy (BAT) in castrate-resistant prostate cancer (CRPC).

2019 ◽  
Vol 37 (7_suppl) ◽  
pp. 200-200
Author(s):  
Michael Thomas Schweizer ◽  
Emmanuel S. Antonarakis ◽  
Mario A. Eisenberger ◽  
Peter Nelson ◽  
Jun Luo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Progression Free Survival ◽  
Cell Cycle Regulators ◽  
Next Generation ◽  
Damage Repair ◽  
Somatic Alterations ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant ◽  
Next Generation Sequencing Ngs

200 Background: BAT is a promising treatment for CRPC and preclinical work has shown that its effects may be mediated by inducing DNA damage or cell cycle arrest. We sought to evaluate if mutations in DNA damage repair (DDR) genes or cell cycle regulators were associated with improved outcomes. Methods: Biospecimens from CRPC patients enrolled to studies testing BAT underwent germline or somatic next-generation sequencing (NGS). Samples tested included plasma (i.e. cell-free DNA) (N = 79), tumor tissue (N = 21) and saliva (N = 10). A variety of clinical grade NGS platforms were generally used. Given the concern for false negatives, we excluded cases if plasma NGS did not reveal a somatic alteration. Absence of a germline alteration was not assumed to indicate absence of somatic alterations. Comparative analyses to assess candidate biomarkers of BAT efficacy were performed. Results: Most patients received BAT following one or more next generation hormonal therapy, while 6 received BAT as first-line CRPC therapy. Of 65 cases where a germline or somatic pathogenic alteration in any gene was detected, 30 (46%) had evidence of homologous recombination deficiency (HRD), with mutations found in BRCA2 (N = 10), ATM (N = 8), CHEK2 (N = 5), PALB2 (N = 4), CDK12 (N = 3), CHD1 (N = 2), FANCA (N = 1), FANCD2 (N = 1) and BRCA1 (N = 1). TP53 alterations were also common (27/65; 42%). HRD mutations associated with increased PSA50 responses, with a trend toward improved PSA50 responses in TP53 mutated cases too (Table). In a combined analysis, men with HRD and/or TP53 mutations had improved PSA50 responses and near-significant improvement in progression free survival (PFS). Conclusions: These preliminary data suggest that BAT may be most efficacious in cancers harboring mutations in genes involved in DDR and/or cell cycle regulation. These results require prospective confirmation. [Table: see text]

Response to PARP inhibitor therapy in metastatic castrate-resistant prostate cancer (mCRPC) patients with BRCA1/2 versus ATM mutations.

2019 ◽  
Vol 37 (7_suppl) ◽  
pp. 154-154 ◽  
Author(s):  
Catherine Handy Marshall ◽  
Andrea McNatty ◽  
Mario A. Eisenberger ◽  
Alan Haruo Bryce ◽  
Emmanuel S. Antonarakis
Keyword(s):  
Dna Repair ◽  
Parp Inhibitor ◽  
Progression Free Survival ◽  
Johns Hopkins Hospital ◽  
Free Survival ◽  
Exact Test ◽  
Somatic Alterations ◽  
Secondary Endpoints ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

154 Background: Poly ADP-ribose polymerase inhibitors (PARPi) are being studied as a treatment option for men with mCRPC and deficient homologous recombination DNA repair. While the FDA has granted “breakthrough” designation status to olaparib for use in mCRPC patients with either BRCA1/2 or ATM mutations, it is not known if responsiveness to PARPi may be influenced by the mutation type. Because ATM functions as a sensor of DNA damage rather than a mediator of DNA repair, we hypothesized that patients with ATM mutations may not show robust responses to PARPi therapy compared to those with BRCA1/2 mutations. Methods: We conducted a retrospective analysis of mCRPC patients treated with off-label olaparib at Johns Hopkins Hospital and Mayo Clinic Scottsdale who had somatic or germline mutations in BRCA1/ 2 or ATM. The primary endpoint was PSA50 response. Secondary endpoints included overall survival (OS) and radiographic/clinical progression-free survival (PFS). Results: 40 men received olaparib for mCRPC of which 17 had pathogenic mutations (5 ATM-mutant, 12 BRCA1/2-mutant). Eleven (65%) had germline and 6 (35%) had somatic alterations. Five (29%) had Gleason sum ≤7 at diagnosis, 4 (24%) had Gleason sum 8, and 8 (47%) had Gleason sum ≥9. Three (18%) had metastatic disease at diagnosis. Mean age at start of olaparib therapy was 65.6 (range, 52-76) years. Prior chemotherapy was received by 59% of men, and prior abiraterone/enzalutamide by 88% of men. Eleven (65%) had extra-osseous metastases at start of therapy. PSA50 responses were achieved by 10/12 men (83%) with BRCA1/2 mutations and 0/5 men (0%) with ATM mutations (Fisher’s exact test, P= 0.003). Men with BRCA1/2 mutations had a median PFS of 12.3 mo versus 3.3 mo for those with ATM mutations (HR 0.14, 95%CI 0.03-0.60; P= 0.008). There was no difference in OS (HR 0.24, 95%CI 0.03-1.173; P= 0.16). Conclusions: Men with mCRPC harboring mutations in BRCA1/2 appear to have better PSA responses and longer PFS with olaparib compared to men with ATM mutations. ATM-mutant mCRPC patients may require alternative therapies ( e.g. chemotherapy, ATR inhibitors). Larger prospective studies are needed to confirm or refute these preliminary findings.

CX-5461 sensitises DNA damage repair proficient castrate-resistant prostate cancer to PARP inhibition

2021 ◽  
pp. molcanther.0932.2020
Author(s):  
Mitchell G Lawrence ◽  
Laura H Porter ◽  
Nicholas Choo ◽  
David Pook ◽  
Jeremy P Grummet ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Dna Damage ◽  
Dna Damage Repair ◽  
Parp Inhibition ◽  
Damage Repair ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

scholarly journals SOG1 transcription factor promotes the onset of endoreduplication under salinity stress in Arabidopsis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kalyan Mahapatra ◽  
Sujit Roy
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Death ◽  
Transcription Factor ◽  
Programmed Cell Death ◽  
Salinity Stress ◽  
Crucial Role ◽  
Genome Stability ◽  
Cell Cycle Checkpoint ◽  
Cell Cycle Regulators

AbstractAs like in mammalian system, the DNA damage responsive cell cycle checkpoint functions play crucial role for maintenance of genome stability in plants through repairing of damages in DNA and induction of programmed cell death or endoreduplication by extensive regulation of progression of cell cycle. ATM and ATR (ATAXIA-TELANGIECTASIA-MUTATED and -RAD3-RELATED) function as sensor kinases and play key role in the transmission of DNA damage signals to the downstream components of cell cycle regulatory network. The plant-specific NAC domain family transcription factor SOG1 (SUPPRESSOR OF GAMMA RESPONSE 1) plays crucial role in transducing signals from both ATM and ATR in presence of double strand breaks (DSBs) in the genome and found to play crucial role in the regulation of key genes involved in cell cycle progression, DNA damage repair, endoreduplication and programmed cell death. Here we report that Arabidopsis exposed to high salinity shows generation of oxidative stress induced DSBs along with the concomitant induction of endoreduplication, displaying increased cell size and DNA ploidy level without any change in chromosome number. These responses were significantly prominent in SOG1 overexpression line than wild-type Arabidopsis, while sog1 mutant lines showed much compromised induction of endoreduplication under salinity stress. We have found that both ATM-SOG1 and ATR-SOG1 pathways are involved in the salinity mediated induction of endoreduplication. SOG1was found to promote G2-M phase arrest in Arabidopsis under salinity stress by downregulating the expression of the key cell cycle regulators, including CDKB1;1, CDKB2;1, and CYCB1;1, while upregulating the expression of WEE1 kinase, CCS52A and E2Fa, which act as important regulators for induction of endoreduplication. Our results suggest that Arabidopsis undergoes endoreduplicative cycle in response to salinity induced DSBs, showcasing an adaptive response in plants under salinity stress.

scholarly journals Human POLD1 modulates cell cycle progression and DNA damage repair

2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Jing Song ◽  
Ping Hong ◽  
Chengeng Liu ◽  
Yueqi Zhang ◽  
Jinling Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Progression ◽  
Dna Damage Repair ◽  
Cycle Progression ◽  
Damage Repair

scholarly journals Genomic hallmarks of cellular dormancy in cancer and therapeutic implications

2021 ◽  
Author(s):  
Maria Secrier ◽  
Anna Wiecek ◽  
Stephen Cutty ◽  
Daniel Kornai ◽  
Mario Parreno-Centeno ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Therapy Resistance ◽  
Therapeutic Resistance ◽  
Epigenetic Mechanisms ◽  
Therapeutic Implications ◽  
Damage Repair ◽  
Repair Deficiency ◽  
Cell Data ◽  
Cell Cycle Kinase

Abstract Therapy resistance in cancer is often driven by a subpopulation of cells that are temporarily arrested in a non-proliferative, quiescent or ‘dormant’ state, which is difficult to capture and whose mutational drivers remain largely unknown. We developed methodology to uniquely identify this state from transcriptomic signals and characterised its prevalence and genomic constraints in solid primary tumours. We show dormancy preferentially emerges in the context of more stable, less mutated genomes which maintain TP53 integrity and lack the hallmarks of DNA damage repair deficiency, while presenting increased APOBEC mutagenesis. We uncover novel genomic dependencies of this process, including the amplification of the centrosomal gene CEP89 as a driver of dormancy impairment. Lastly, we demonstrate that dormancy underlies unfavourable responses to various therapies exploiting cell cycle, kinase signalling and epigenetic mechanisms in single cell data, and propose a signature of dormancy-linked therapeutic resistance to further study and clinically track this state.

Radiographic progression-free survival as a surrogate endpoint of overall survival in men with metastatic castrate-resistant prostate cancer.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 5057-5057
Author(s):  
Susan Halabi ◽  
Akash Roy ◽  
Qian Yang ◽  
Wanling Xie ◽  
William Kevin Kelly ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Radiographic Progression ◽  
Progression Free Survival ◽  
Surrogate Endpoint ◽  
Phase Iii ◽  
Random Assignment ◽  
Moderate Correlation ◽  
Free Survival ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

5057 Background: Radiographic progression-free survival (rPFS) is commonly used as a co-primary endpoint in randomized clinical trials in men with metastatic castrate-resistant prostate cancer (mCRPC). However, rPFS has not been established as a valid surrogate endpoint of overall survival (OS) in men with mCRPC. Here, we hypothesized that rPFS is a reliable surrogate for OS in mCRPC. We also explored whether PFS is a valid surrogate endpoint of OS at the aggregate trial level. Methods: We performed a systematic search of the literature encompassing the period January 2004-December 2020 using PubMed and clinical trials.gov to identify completed phase III trials in mCRPC post-docetaxel. Eligible trials had to be randomized phase III therapeutic trials that reported OS, PFS or rPFS. OS was measured from the date of random assignment to date of death from any cause or date of last follow-up. rPFS was defined as the time from random assignment to date of disease progression on CT and/or Tc bone scan per trial definition or death from any cause, whichever occurred first. PFS included PSA progression as a component of the composite endpoint. Trial level surrogacy was evaluated by fitting linear regression on the treatment effect of rPFS (or PFS) and OS (in other words, the weighted linear regression of the log(hazard ratio) of OS on the log(hazard ratio) of rPFS). It was pre-specified that rPFS would be considered a valid surrogate for OS if R² was 0·7 or higher. Results: We identified 33 in men with mCRPC post docetaxel approval. We assessed the association between PFS and OS in 29,456 patients from 30 trials. Overall, a moderate correlation was observed at the trial level between OS and PFS ( R2 = 0.46, 95 %CI = 0.20-0.68) in these trials. In 18 trials with 16,818 mCRPC patients where rPFS was considered as a key endpoint, a moderate correlation between the treatment effects on rPFS and OS was observed at the trial level ( R2= 0.65, 95% CI = 0.23-0.87). Conclusions: This meta-analysis demonstrates moderate correlation between treatment effects of rPFS and OS in patients with mCRPC. However, rPFS did not meet the pre-specified surrogacy threshold of 0.7. Clinical trial information: several.

scholarly journals Changes in DNA Damage Repair Gene Expression and Cell Cycle Gene Expression Do Not Explain Radioresistance in Tamoxifen-Resistant Breast Cancer

2020 ◽  
Vol 28 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Annemarie E. M. Post ◽  
Johan Bussink ◽  
Fred C. G. J. Sweep ◽  
Paul N. Span
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cell Cycle ◽  
Dna Damage ◽  
Dna Damage Repair ◽  
Cross Resistance ◽  
Damage Repair ◽  
Breast Cancer Cohort ◽  
Tamoxifen Resistant ◽  
Repair Genes

Tamoxifen-induced radioresistance, reported in vitro, might pose a problem for patients who receive neoadjuvant tamoxifen treatment and subsequently receive radiotherapy after surgery. Previous studies suggested that DNA damage repair or cell cycle genes are involved, and could therefore be targeted to preclude the occurrence of cross-resistance. We aimed to characterize the observed cross-resistance by investigating gene expression of DNA damage repair genes and cell cycle genes in estrogen receptor-positive MCF-7 breast cancer cells that were cultured to tamoxifen resistance. RNA sequencing was performed, and expression of genes characteristic for several DNA damage repair pathways was investigated, as well as expression of genes involved in different phases of the cell cycle. The association of differentially expressed genes with outcome after radiotherapy was assessed in silico in a large breast cancer cohort. None of the DNA damage repair pathways showed differential gene expression in tamoxifen-resistant cells compared to wild-type cells. Two DNA damage repair genes were more than two times upregulated (NEIL1 and EME2), and three DNA damage repair genes were more than two times downregulated (PCNA, BRIP1, and BARD1). However, these were not associated with outcome after radiotherapy in the TCGA breast cancer cohort. Genes involved in G1, G1/S, G2, and G2/M phases were lower expressed in tamoxifen-resistant cells compared to wild-type cells. Individual genes that were more than two times upregulated (MAPK13) or downregulated (E2F2, CKS2, GINS2, PCNA, MCM5, and EIF5A2) were not associated with response to radiotherapy in the patient cohort investigated. We assessed the expression of DNA damage repair genes and cell cycle genes in tamoxifen-resistant breast cancer cells. Though several genes in both pathways were differentially expressed, these could not explain the cross-resistance for irradiation in these cells, since no association to response to radiotherapy in the TCGA breast cancer cohort was found.

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