scholarly journals Clinical Impact of Somatic Variants in Homologous Recombination Repair-Related Genes in Ovarian High-Grade Serous Carcinoma

2020 ◽  
Vol 52 (2) ◽  
pp. 634-644 ◽  
Author(s):  
Min Chul Choi ◽  
Sohyun Hwang ◽  
Sewha Kim ◽  
Sang Geun Jung ◽  
Hyun Park ◽  
...  

PurposeIn this study, we investigated the frequencies of mutations in DNA damage repair genes including <i>BRCA1</i>, <i>BRCA2</i>, homologous recombination genes and <i>TP53</i> gene in ovarian high-grade serous carcinoma, alongside those of germline and somatic <i>BRCA</i> mutations, with the aim of improving the identification of patients suitable for treatment with poly(ADP-ribose) polymerase inhibitors.Materials and MethodsTissue samples from 77 Korean patients with ovarian high-grade serous carcinoma were subjected to next-generation sequencing. Pathogenic alterations of 38 DNA damage repair genes and <i>TP53</i> gene and their relationships with patient survival were examined. Additionally, we analyzed <i>BRCA</i> germline variants in blood samples from 47 of the patients for comparison.Results<i>BRCA1</i>, <i>BRCA2</i>, and <i>TP53</i> mutations were detected in 28.6%, 5.2%, and 80.5% of the 77 patients, respectively. Alterations in <i>RAD50, ATR, MSH6, MSH2</i>, and <i>FANCA</i> were also identified. At least one mutation in a DNA damage repair gene was detected in 40.3% of patients (31/77). Germline and somatic <i>BRCA</i> mutations were found in 20 of 47 patients (42.6%), and four patients had only somatic mutations without germline mutations (8.5%, 4/47). Patients with DNA damage repair gene alterations with or without <i>TP53</i>mutation, exhibited better disease-free survival than those with <i>TP53</i> mutation alone.ConclusionDNA damage repair genes were mutated in 40.3% of patients with high-grade serous carcinoma, with somatic <i>BRCA</i> mutations in the absence of germline mutation in 8.5%. Somatic variant examination, along with germline testing of DNA damage repair genes, has potential to detect additional candidates for PARP inhibitor treatment.

2015 ◽  
Vol 7 ◽  
pp. e2015046 ◽  
Author(s):  
Sudhansu Sekhar Nishank

Background– Defect in DNA damage repair genes due to oxidative stress predispose the humans to malignancies. There are many cases of association of malignancies with sickle cell disease patients (SCD) throughout the world, the molecular cause of which has never been investigated. DNA damage repair genes such as  hOGG1, XRCC1 and p53 play significant role in repair of DNA damage during oxidative stress but the distribution and clinical effect of these genes are not known till date in SCD patients who are associated with oxidative stress related clinical complications.        Objective – The aim of the study was to characterize the distribution and clinical effect of DNA damage gene polymorphisms p53 (codon 72 Arg> Pro), hOGG1 (codon 326 Ser>Cyst) and XRCC1 (codons 194 Arg>Trp, codon 280 Arg> His, codon 399 Arg> Gln) among SCD patients of  central India. Methods- A case control study of  250 SCD patients and 250 normal individuals were investigated by PCR-RFLP techniques.     Result- The prevalence of mutant alleles of hOGG1 gene, XRCC1 codon 280 Arg>His  were found to be significantly high among SCD patients as compared to controls. However, SCD patients did not show clinical association with any of these DNA repair gene polymorphisms.  Conclusion- This indicates that hOGG1, p53  and XRCC1 gene polymorphisms  may not have any clinical impact among SCD patients in India.


2019 ◽  
Vol 20 (19) ◽  
pp. 4728 ◽  
Author(s):  
Hwani Ryu ◽  
Hyun-Kyung Choi ◽  
Hyo Jeong Kim ◽  
Ah-Young Kim ◽  
Jie-Young Song ◽  
...  

Class III receptor tyrosine kinase (RTK) inhibitors targeting mainly FLT3 or c-KIT have not been well studied in lung cancer. To identify a small molecule potentially targeting class III RTK, we synthesized novel small molecule compounds and identified 5-(4-bromophenyl)-N-(naphthalen-1-yl) oxazol-2-amine (AIU2001) as a novel class III RKT inhibitor. In an in vitro kinase profiling assay, AIU2001 inhibited the activities of FLT3, mutated FLT3, FLT4, and c-KIT of class III RTK, and the proliferation of NSCLC cells in vitro and in vivo. AIU2001 induced DNA damage, reactive oxygen species (ROS) generation, and cell cycle arrest in the G2/M phase. Furthermore, AIU2001 suppressed the DNA damage repair genes, resulting in the ‘BRCAness’/‘DNA-PKness’ phenotype. The mRNA expression level of STAT5 was downregulated by AIU2001 treatment and knockdown of STAT5 inhibited the DNA repair genes. Our results show that compared to either drug alone, the combination of AIU2001 with a poly (ADP-ribose) polymerase (PARP) inhibitor olaparib or irradiation showed synergistic efficacy in H1299 and A549 cells. Hence, our findings demonstrate that AIU2001 is a candidate therapeutic agent for NSCLC and combination therapies with AIU2001 and a PARP inhibitor or radiotherapy may be used to increase the therapeutic efficacy of AIU2001 due to inhibition of DNA damage repair.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 5038-5038
Author(s):  
Jose Mauricio Mota ◽  
Ethan Barnett ◽  
Jones Nauseef ◽  
Konrad Hermann Stopsack ◽  
Andreas Georg Wibmer ◽  
...  

5038 Background: Platinum-based chemotherapy has shown palliative and radiographic benefit in small unselected studies of metastatic castration-resistant prostate cancer (mCRPC). Alterations in DNA damage repair genes (DDRmut), which occur in ~25% of patients with mCRPC, may sensitize to platinum-based chemotherapy, and may aid in the selection of patients for this therapy. We sought to evaluate the efficacy of platinum-based chemotherapy in DDRmut mCRPC. Methods: We performed a retrospective review of patients with prostate cancer who underwent tumor genomic profiling and received platinum-based chemotherapy. Deleterious alterations in a panel including BRCA2, BRCA1, ATM, FANCA, CDK12 or PALB2 were classified as DDRmut. Absence of deleterious alterations in those genes was classified as DDRwt. MSI-H cases were excluded from analysis. Electronic charts, PSA values, and scans were reviewed to assess for outcomes. Results: From October 2013 to July 2018, 109 patients with mCRPC received platinum-based chemotherapy. 64/109 had prior taxane progression and were PARP inhibitor (PARPi) naïve at the time of platinum-based chemotherapy. DDRmut was found in 16/64 (25%) of patients ( BRCA2, n = 6; ATM, n = 2; CDK12, n = 4; FANCA, n = 4; PALB2, n = 1). Visceral metastasis occurred in 4/16 (25%) of DDRmut patients and in 22/48 (46%) of DDRwt patients. PSA50 responses were more common among DDRmut (8/15 evaluable = 53%, 95% CI, 30-75%) than among DDRwt patients (5/42 evaluable = 12%, 95% CI, 5-25%). Time on platinum-based chemotherapy tended to be longer in the DDRmut group (median 3.1 vs 1.8 months; HR 0.73, 95% CI 0.42-1.26). Of 8 DDRmut patients ( BRCA2, n = 6; BRCA1, n = 1; ATM, n = 2) who received platinum-based chemotherapy after progression on a PARPi, 3/7 evaluable patients (43%) had RECIST response or stable disease, and 2/7 evaluable patients (29%) had a PSA50 response. Of 4 patients with ATM deleterious mutations, none had a radiographic or PSA50 response to platinum-based chemotherapy. Conclusions: Platinum-based chemotherapy showed activity in DDRmut mCRPC patients before and after PARPi treatment.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 5031-5031 ◽  
Author(s):  
Wassim Abida ◽  
Alan Haruo Bryce ◽  
Nicholas J. Vogelzang ◽  
Robert J. Amato ◽  
Ivor John Percent ◽  
...  

5031 Background: The phase 2 TRITON2 study (NCT02952534) is evaluating the PARP inhibitor rucaparib in patients with mCRPC who have a deleterious germline or somatic alteration in BRCA ( BRCA1 or BRCA2) or 1 of 13 other DNA damage repair genes. Here we present analyses of tumor genomics and baseline clinical characteristics in mCRPC patients with a deleterious alteration in BRCA. Methods: Plasma (baseline) and tissue (archival or baseline) samples from patients with a deleterious alteration in BRCA were analyzed using Foundation Medicine next-generation sequencing assays. The alterations and zygosity of the alterations that were detected, as well as the somatic/germline status from Color Genomics testing, were summarized. Associations between genomic alterations, DNA yield, allele frequency, and baseline clinical characteristics were investigated. Results: Results are shown in the Table for a cohort of 40 BRCA2 and 5 BRCA1 patients enrolled in TRITON2 (Abida W et al. Presented at ESMO 2018. Abst 793PD). A biallelic alteration was observed in 21 of the 22 BRCA2 patients (95%) for whom alteration zygosity could be determined. Among the 5 BRCA1 patients, 1 alteration was monoallelic and 4 were of unknown zygosity. Co-occurring alterations in cancer-related or DNA damage repair genes were observed in many patients with BRCA alterations. At baseline, cell-free DNA (cfDNA) yield correlated positively with the sum of target lesions (STL; P= 0.04), but not with prostate-specific antigen (PSA) levels ( P= 0.86). No correlation was observed between allele frequency of the BRCA alteration baseline STL ( P= 0.68) or PSA levels ( P= 0.97). Conclusions: Patients with a BRCA mutation enrolled in TRITON2 demonstrate a profile of genomic alterations consistent with that of prior studies of patients with mCRPC. Plasma cfDNA profiling showed a correlation between baseline cfDNA yield and measurable tumor burden, but not baseline PSA. Clinical trial information: NCT02952534. [Table: see text]


2021 ◽  
Vol 16 (3) ◽  
pp. S534-S535
Author(s):  
Z. Yu ◽  
S. Dang ◽  
J. Zhang ◽  
J. Duan ◽  
S. Chen ◽  
...  

2021 ◽  
Author(s):  
David S. Moura ◽  
Maria Peña‐Chilet ◽  
Juan Antonio Cordero Varela ◽  
Ramiro Alvarez‐Alegret ◽  
Carolina Agra‐Pujol ◽  
...  

2004 ◽  
Vol 38 (6) ◽  
pp. 954-968 ◽  
Author(s):  
Fabian Heitzeberg ◽  
I-Peng Chen ◽  
Frank Hartung ◽  
Nadiya Orel ◽  
Karel J. Angelis ◽  
...  

2017 ◽  
Vol 9 (5) ◽  
pp. 1660-1674 ◽  
Author(s):  
Kalpana Mujoo ◽  
Raj K. Pandita ◽  
Anjana Tiwari ◽  
Vijay Charaka ◽  
Sharmistha Chakraborty ◽  
...  

Author(s):  
Annemarie E. M. Post ◽  
Johan Bussink ◽  
Fred C. G. J. Sweep ◽  
Paul N. Span

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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