Baseline pathogenic mutations in non-AR/non-TP53 genes and prediction of response to high-dose testosterone.

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 146-146
Author(s):  
Ellen Jaeger ◽  
Sydney Caputo ◽  
Elisa Marie Ledet ◽  
Marcus W. Moses ◽  
Jodi Lyn Layton ◽  
...  
Keyword(s):  
Dna Repair ◽  
Gene Selection ◽  
Point Mutations ◽  
Predictive Biomarker ◽  
High Dose ◽  
Pathogenic Mutations ◽  
Brca1 Brca2 ◽  
Axis Drive ◽  
Allelic Fraction

146 Background: The fact that high dose of testosterone (HDT) elicits positive responses in a subset of prostate cancer patients (pts) is surprising and puzzling. Genomics data differentiating responders (Rs) from non-responders (NRs) is sparse. Pts with mutations in DNA repair pathway genes may be particularly sensitive to HDT (see BA Teply et al. Eur Urol 71:499, 2017). Herein we perform exploratory analyses to better understand the role of pathogenic mutations (muts) in ctDNA as a predictive biomarker for patients treated with HDT. Methods: ctDNA essays were performed with the Guardant360 methodology pre-HDT. Point mutations were classified by cancervar (http://cancervar.wglab.org). Truncating mutations (frameshift and nonsense) were manually curated to assess for pathogenicity. All patients had CRPC and were pre-treated with abiraterone and/or enzalutamide. HDT was typically administered as 400 mg testosterone cypionate q 3-4 weeks. Rs were compared to NRs. All Rs had >3 more cycles of HDT and a >50% PSA decline (N = 17). Non-responders had <3 cycles and no PSA decline (N = 23). Only muts with an allelic fraction of >0.5% were analyzed given dubious importance of mutations with lower allelic fractions. Results: AR muts (4/17 vs 6/23 in Rs and NRs) and TP53 muts (10/17 vs 11/23 in Rs and NRs) were similar ( P= 0.85 and 0.49, respectively) but the number of pts with non-AR/non-TP53 muts was distinct (3/17 for Rs, and 12/23 for NRs; P= 0.026). The average number of non-AR/non-TP53 muts (Rs = 0.23 and NRs = 0.83) was higher in the NRs (P = 0.046). When analyzing DNA repair alterations, no differences were noted in those with BRCA1/BRCA2/ATM mutations in the Rs and NRs (1/17 vs 6/23 respectively; P= 0.09). Conclusions: AR and TP53 pathogenic mutations are common in both Rs and NRs but other pathogenic mutations are more common in non-responders. We hypothesize that genetic pathways outside of the AR/TP53 axis drive resistance to HDT. Additional studies are warranted to assess whether or not these pathways drive resistance to HDT. Limitations are acknowledged with regard to the Guardant assay gene selection for CRPC pts.

scholarly journals DNA Repair and Transcriptional Deficiencies Caused by Mutations in the Drosophila p52 Subunit of TFIIH Generate Developmental Defects and Chromosome Fragility

2007 ◽  
Vol 27 (10) ◽  
pp. 3640-3650 ◽  
Author(s):  
Mariana Fregoso ◽  
Jean-Philippe Lainé ◽  
Javier Aguilar-Fuentes ◽  
Vincent Mocquet ◽  
Enrique Reynaud ◽  
...  
Keyword(s):  
Dna Repair ◽  
Biochemical Analysis ◽  
Excision Repair ◽  
Uv Light ◽  
Point Mutations ◽  
Developmental Defects ◽  
Nucleotide Excision ◽  
Chromosome Fragility ◽  
Repair Factor

ABSTRACT The transcription and DNA repair factor TFIIH is composed of 10 subunits. Mutations in the XPB, XPD, and p8 subunits are genetically linked to human diseases, including cancer. However, no reports of mutations in other TFIIH subunits have been reported in higher eukaryotes. Here, we analyze at genetic, molecular, and biochemical levels the Drosophila melanogaster p52 (DMP52) subunit of TFIIH. We found that DMP52 is encoded by the gene marionette in Drosophila and that a defective DMP52 produces UV light-sensitive flies and specific phenotypes during development: organisms are smaller than their wild-type siblings and present tumors and chromosomal instability. The human homologue of DMP52 partially rescues some of these phenotypes. Some of the defects observed in the fly caused by mutations in DMP52 generate trichothiodystrophy and cancer-like phenotypes. Biochemical analysis of DMP52 point mutations introduced in human p52 at positions homologous to those of defects in DMP52 destabilize the interaction between p52 and XPB, another TFIIH subunit, thus compromising the assembly of the complex. This study significantly extends the role of p52 in regulating XPB ATPase activity and, consequently, both its transcriptional and nucleotide excision repair functions.

scholarly journals Therapeutic Potential of PARP Inhibitors in the Treatment of Gastrointestinal Cancers

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1024
Author(s):  
Abdullah Alhusaini ◽  
Aoife Cannon ◽  
Stephen G. Maher ◽  
John V. Reynolds ◽  
Niamh Lynam-Lennon
Keyword(s):  
Treatment Response ◽  
Therapeutic Potential ◽  
Predictive Biomarker ◽  
Parp Inhibitors ◽  
Current Evidence ◽  
Combination Strategies ◽  
Gi Cancer ◽  
Brca1 Brca2 ◽  
Novel Therapeutic Strategies

Gastrointestinal (GI) malignancies are a major global health burden, with high mortality rates. The identification of novel therapeutic strategies is crucial to improve treatment and survival of patients. The poly (ADP-ribose) polymerase (PARP) enzymes involved in the DNA damage response (DDR) play major roles in the development, progression and treatment response of cancer, with PARP inhibitors (PARPi) currently used in the clinic for breast, ovarian, fallopian, primary peritoneal, pancreatic and prostate cancers with deficiencies in homologous recombination (HR) DNA repair. This article examines the current evidence for the role of the DDR PARP enzymes (PARP1, 2, 3 and 4) in the development, progression and treatment response of GI cancers. Furthermore, we discuss the role of HR status as a predictive biomarker of PARPi efficacy in GI cancer patients and examine the pre-clinical and clinical evidence for PARPi and cytotoxic therapy combination strategies in GI cancer. We also include an analysis of the genomic and transcriptomic landscape of the DDR PARP genes and key HR genes (BRCA1, BRCA2, ATM, RAD51, MRE11, PALB2) in GI patient tumours (n = 1744) using publicly available datasets to identify patients that may benefit from PARPi therapeutic approaches.

DNA damage response and repair (DDR) gene mutations and correlation with tumor mutation burden (TMB) in non-small cell lung cancer (NSCLC).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 9100-9100 ◽  
Author(s):  
Hirva Mamdani ◽  
Jerry Chen ◽  
Seongho Kim ◽  
Yahya Ibrahim ◽  
Mohammad Fahad Bin Asad ◽  
...  
Keyword(s):  
Dna Repair ◽  
Immune Checkpoint ◽  
Gene Mutations ◽  
Predictive Biomarker ◽  
Immune Checkpoint Blockade ◽  
Parp Inhibition ◽  
Tumor Evolution ◽  
Immune Biomarkers ◽  
Dna Repair Deficiency ◽  
Brca1 Brca2

9100 Background: Loss of DNA repair fidelity is a common feature of human cancers and can drive genomic instability and tumor evolution. DNA repair deficiency has also emerged as a predictive biomarker of response to PARP inhibition and more recently to immune checkpoint inhibition. Information on relationship between DNA repair defects and TMB in NSCLC is limited. Methods: We analyzed molecular profiles of 5667 NSCLC tumors harboring mutations in DDR genes ( ATM, ATR, BARD1, BLM, BRCA1/2, BRIP1, CHEK1/2, ERCC2/3, FANCA/C/D2/E/F/G/L, MLH1, MSH2/6, MRE11, NBN, PALB2, POLE, PTEN, RAD50/51, WRN). Profiles included next-generation sequencing of 592 genes, TMB, and PD-L1 (22c3) by immunohistochemistry. Association of DDR gene mutations with immune biomarkers (TMB and PD-L1) was assessed. Results: Of the 5667 samples, 54% (n = 3060) had high TMB (defined as ≥10 mutations/Mb) with median TMB of 14 (range, 10-168). Among the remaining 46% (n = 2607) with low TMB, median TMB was 7 (range, 1-9). PD-L1 expression was high (≥50%) in 33% (n = 1878), intermediate (1-49%) in 26% (n = 1446), and negative ( < 1%) in 41% (n = 2343). Among all DDR mutated pts, 19% (n = 1058) had both high PD-L1 and high TMB, 35% (n = 2002) had high TMB alone, 15% (n = 820) had high PD-L1 alone. Most commonly mutated genes were RAD50 (52%), WRN (29%), CHEK2 (20%), ATM (19%), MRE11 (19%), and ATR (18%). Genes with a high likelihood of being associated with high TMB were ATM, ATR, BARD1, BRCA1, BRCA2, ERCC2, ERCC3, FANCA, MSH2, PALB2, and POLE. Strongest association was seen with BRCA1 (OR 1.81, 95% CI 1.47-2.22), PALB2 (OR 1.76, 95% CI 1.40-2.21), and POLE (OR 1.71, 95% CI 1.45-2.01). DDR genes mutations were not mutually exclusive - 77.5% (n = 4397) had 2 or more mutated genes. Tumors with ≥3 mutated genes were more likely to be associated with high TMB. No such correlation was observed with PD-L1 expression. Conclusions: The majority of NSCLC pts harboring DDR gene mutations have high TMB. Presence of ≥3 gene mutations and BRCA1, PALB2, and POLE mutations strongly correlate with high TMB. These patients may represent a unique subset that is more likely to benefıt from immune checkpoint blockade and PARP inhibition.

Pre-emptive Analgesia for Postoperative Pain Relief in Children – Role of Paracetamol

2009 ◽  
pp. 9-16
Author(s):  
Rubina Yasmin ◽  
AKM Akhtaruzzaman ◽  
Paresh Chandra Sarker ◽  
Neaz Ahmed ◽  
Ranadhir Kumar Kundu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Postoperative Pain ◽  
Diclofenac Sodium ◽  
Total Duration ◽  
Pain Scale ◽  
Prospective Clinical Study ◽  
High Dose ◽  
Induction Of Anaesthesia

This prospective clinical study was carried out in the Dept. of Anaesthesia, Analgesia and Intensive Care Medicine, BSMMU, Dhaka, during the period of May 2003 to July 2003. The study was done to emphasize the importance of giving analgesics preemptively instead of waiting for the child to complain of pain and to produce smooth recovery after surgery by decreasing immediate postoperative pain in children by a simple, safe acceptable drug. The children scheduled for tonsillectomy under general anaesthesia were recruited in this study. The analgesic efficiency of rectal paracetamol in two doses, 25 mg/kg bodywt.(Gr-P25) and 50 mg/kg. bodywt. (Gr-P50) were compared with Diclofenac Sodium suppository 1mg/ kg body weight (Gr-D) given half an hour before induction of anaesthesia. Pain scoring was done by TPPPS (Toddler Pre-schooler postoperative pain scale). Heart rate and blood pressure were stable in Gr-P50 and Gr-D. Time of first demand of analgesic was delayed in Gr-P50 and Gr-D. Total paracetamol consumption in 24 hours was less in Gr-P50(181±14.25) and Gr-D (212±25) than Gr-P25(318± 26.39). Total duration of analgesia in Gr- P50 (657±9.94) mins. and in Gr- D(502±10.63) mins. and in Gr-P25(288±23.17) mins. Pre-emptive high dose rectal paracetamol appears to be more effective than diclofenac sodium suppository for postoperative analgesia in children undergoing tonsillectomy. Journal of BSA, Vol. 18, No. 1 & 2, 2005 p.9-16

Role of key point Mutations in Receptor Binding Domain of SARS-CoV-2 Spike Glycoprotein

2020 ◽  
Vol 20 ◽  
Author(s):  
Bipin Singh
Keyword(s):  
Receptor Binding ◽  
Point Mutations ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Spike Glycoprotein ◽  
Angiotensin Converting Enzyme 2 ◽  
Recent Outbreak ◽  
Novel Coronavirus ◽  
Genomic Similarity

: The recent outbreak of novel coronavirus (SARS-CoV-2 or 2019-nCoV) and its worldwide spread is posing one of the major threats to human health and the world economy. It has been suggested that SARS-CoV-2 is similar to SARSCoV based on the comparison of the genome sequence. Despite the genomic similarity between SARS-CoV-2 and SARSCoV, the spike glycoprotein and receptor binding domain in SARS-CoV-2 shows the considerable difference compared to SARS-CoV, due to the presence of several point mutations. The analysis of receptor binding domain (RBD) from recently published 3D structures of spike glycoprotein of SARS-CoV-2 (Yan, R., et al. (2020); Wrapp, D., et al. (2020); Walls, A. C., et al. (2020)) highlights the contribution of a few key point mutations in RBD of spike glycoprotein and molecular basis of its efficient binding with human angiotensin-converting enzyme 2 (ACE2).

scholarly journals Role of Mis Localization of DNA Repair Factors in Cell Cycle Arrest

2019 ◽  
Vol 116 (3) ◽  
pp. 76a
Author(s):  
Manasvita Vashisth ◽  
Sangkyun Cho ◽  
Dennis Discher
Keyword(s):  
Cell Cycle ◽  
Dna Repair ◽  
Cell Cycle Arrest ◽  
Cycle Arrest

scholarly journals A Role for Histone H2B During Repair of UV-Induced DNA Damage in Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1375-1387
Author(s):  
Emmanuelle M D Martini ◽  
Scott Keeney ◽  
Mary Ann Osley
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Chromatin Structure ◽  
Specific Effect ◽  
Cell Killing ◽  
Cyclobutane Pyrimidine Dimers ◽  
Histone H2b ◽  
Uv Sensitivity ◽  
Pyrimidine Dimers

Abstract To investigate the role of the nucleosome during repair of DNA damage in yeast, we screened for histone H2B mutants that were sensitive to UV irradiation. We have isolated a new mutant, htb1-3, that shows preferential sensitivity to UV-C. There is no detectable difference in bulk chromatin structure or in the number of UV-induced cis-syn cyclobutane pyrimidine dimers (CPD) between HTB1 and htb1-3 strains. These results suggest a specific effect of this histone H2B mutation in UV-induced DNA repair processes rather than a global effect on chromatin structure. We analyzed the UV sensitivity of double mutants that contained the htb1-3 mutation and mutations in genes from each of the three epistasis groups of RAD genes. The htb1-3 mutation enhanced UV-induced cell killing in rad1Δ and rad52Δ mutants but not in rad6Δ or rad18Δ mutants, which are defective in postreplicational DNA repair (PRR). When combined with other mutations that affect PRR, the histone mutation increased the UV sensitivity of strains with defects in either the error-prone (rev1Δ) or error-free (rad30Δ) branches of PRR, but did not enhance the UV sensitivity of a strain with a rad5Δ mutation. When combined with a ubc13Δ mutation, which is also epistatic with rad5Δ, the htb1-3 mutation enhanced UV-induced cell killing. These results suggest that histone H2B acts in a novel RAD5-dependent branch of PRR.

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