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The Mec1/ATR kinase is crucial for genome stability, yet the mechanism by which it prevents gross chromosomal rearrangements (GCRs) remains unknown. Here we find that in cells with deficient Mec1 signaling, GCRs accumulate due to the deregulation of multiple steps in homologous recombination (HR). Mec1 primarily suppresses GCRs through its role in activating the canonical checkpoint kinase Rad53, which ensures the proper control of DNA end resection. Upon loss of Rad53 signaling and resection control, Mec1 becomes hyperactivated and triggers a salvage pathway in which the Sgs1 helicase is recruited to sites of DNA lesions via the 911-Dpb11 scaffolds and phosphorylated by Mec1 to favor heteroduplex rejection and limit HR-driven GCR accumulation. Fusing an ssDNA recognition domain to Sgs1 bypasses the requirement of Mec1 signaling for GCR suppression and nearly eliminates D-loop formation, thus preventing non-allelic recombination events. We propose that Mec1 regulates multiple steps of HR to prevent GCRs while ensuring balanced HR usage when needed for promoting tolerance to replication stress.

PURPOSE: Germline pathogenic variants in checkpoint kinase 2 (CHEK2) are associated with a moderately increased risk of breast cancer (BC). The spectrum of clinicopathologic features and genetics of these tumors has not been fully established. METHODS: We characterized the histopathologic and clinicopathologic features of 44 CHEK2-associated BCs from 35 women, and assessed responses to neoadjuvant chemotherapy. A subset of cases (n = 23) was additionally analyzed using targeted next-generation DNA sequencing (NGS). RESULTS: Most (94%, 33/35) patients were heterozygous carriers for germline CHEK2 variants, and 40% had the c.1100delC allele. Two patients were homozygous, and five had additional germline pathogenic variants in ATM (2), PALB2 (1), RAD50 (1), or MUTYH (1). CHEK2-associated BCs occurred in younger women (median age 45 years, range 25-75) and were often multifocal (20%) or bilateral (11%). Most (86%, 38/44) were invasive ductal carcinomas of no special type (IDC-NST). Almost all (95%, 41/43) BCs were ER + (79% ER + HER2-, 16% ER + HER2 + , 5% ER-HER2 +), and most (69%) were luminal B. Nottingham grade, proliferation index, and results of multiparametric molecular testing were heterogeneous. Biallelic CHEK2 alteration with loss of heterozygosity was identified in most BCs (57%, 13/23) by NGS. Additional recurrent alterations included GATA3 (26%), PIK3CA (226%), CCND1 (22%), FGFR1 (22%), ERBB2 (17%), ZNF703 (17%), TP53 (9%), and PPM1D (9%), among others. Responses to neoadjuvant chemotherapy were variable, but few patients (21%, 3/14) achieved pathologic complete response. Most patients (85%) were without evidence of disease at time of study (n = 34). Five patients (15%) developed distant metastasis, and one (3%) died (mean follow-up 50 months). CONCLUSION: Almost all CHEK2-associated BCs were ER + IDC-NST, with most classified as luminal B with or without HER2 overexpression. NGS supported the luminal-like phenotype and confirmed CHEK2 as an oncogenic driver in the majority of cases. Responses to neoadjuvant chemotherapy were variable but mostly incomplete.

Genomic instability is a core characteristic of cancer, often stemming from defects in DNA damage response (DDR) or increased replication stress. DDR defects can lead to significant genetic alterations, including changes in gene copy numbers, gene rearrangements, and mutations, which accumulate over time and drive the clonal evolution of cancer cells. However, these vulnerabilities also present opportunities for targeted therapies that exploit DDR deficiencies, potentially improving treatment efficacy and patient outcomes. The development of PARP inhibitors like Olaparib has significantly improved the treatment of cancers with DDR defects (e.g., BRCA1 or BRCA2 mutations) based on synthetic lethality. This achievement has spurred further research into identifying additional therapeutic targets within the DDR pathway. Recent progress includes the development of inhibitors targeting other key DDR components such as DNA-PK, ATM, ATR, Chk1, Chk2, and Wee1 kinases. Current research is focused on optimizing these therapies by developing predictive biomarkers for treatment response, analyzing mechanisms of resistance (both intrinsic and acquired), and exploring the potential for combining DDR-targeted therapies with chemotherapy, radiotherapy, and immunotherapy. This article provides an overview of the latest advancements in targeted anti-tumor therapies based on DDR and their implications for future cancer treatment strategies. [ABSTRACT FROM AUTHOR]

Context CHEK2 is a cell cycle checkpoint regulator gene with a long-established role as a clinically relevant, moderate risk breast cancer predisposition gene, with greater risk ascribed to truncating variants than missense variants. Objective To assess the rate and pathogenicity of CHEK2 variants amongst individuals with pituitary adenomas (PAs). Methods We assessed 165 individuals with PAs for CHEK2 variants. The study population comprised a primary cohort of 29 individuals who underwent germline and tumor whole-exome sequencing, and a second, independent cohort of 136 individuals who had a targeted next-generation sequencing panel performed on both germline and tumor DNA (n = 52) or germline DNA alone (n = 84). Results We identified rare, coding, nonsynonymous germline CHEK2 variants amongst 3 of 29 (10.3%) patients in our primary cohort, and in 5 of 165 (3.0%) patients overall, with affected patients having a range of PA types (prolactinoma, thyrotropinoma, somatotropinoma, and nonfunctioning PA). No somatic variants were identified. Two variants were definitive null variants (c.1100delC, c.444 + 1G > A), classified as pathogenic. Two variants were missense variants (p.Asn186His, p.Thr476Met), classified as likely pathogenic. Even when considering the null variants only, the rate of CHEK2 variants was higher in our cohort compared to national control data (1.8% vs 0.5%; P =.049). Conclusion This is the first study to suggest a role for the breast cancer predisposition gene, CHEK2 , in pituitary tumorigenesis, with pathogenic/likely pathogenic variants found in 3% of patients with PAs. As PAs are relatively common and typically lack classic autosomal dominant family histories, risk alleles—such as these variants found in CHEK2 —might be a significant contributor to PA risk in the general population. [ABSTRACT FROM AUTHOR]

Background: Aside from the canonical role of PDL1 as a tumour surface-expressed immune checkpoint molecule, tumour-intrinsic PDL1 signals regulate non-canonical immunopathological pathways mediating treatment resistance whose significance, mechanisms, and therapeutic targeting remain incompletely understood. Recent reports implicate tumour-intrinsic PDL1 signals in the DNA damage response (DDR), including promoting homologous recombination DNA damage repair and mRNA stability of DDR proteins, but many mechanistic details remain undefined. Methods: We genetically depleted PDL1 from transplantable mouse and human cancer cell lines to understand consequences of tumour-intrinsic PDL1 signals in the DNA damage response. We complemented this work with studies of primary human tumours and inducible mouse tumours. We developed novel approaches to show tumour-intrinsic PDL1 signals in specific subcellular locations. We pharmacologically depleted tumour PDL1 in vivo in mouse models with repurposed FDA-approved drugs for proof-of-concept clinical translation studies. Results: We show that tumour-intrinsic PDL1 promotes the checkpoint kinase-2 (Chk2)-mediated DNA damage response. Intracellular but not surface-expressed PDL1 controlled Chk2 protein content post-translationally and independently of PD1 by antagonising PIRH2 E3 ligase-mediated Chk2 polyubiquitination and protein degradation. Genetic tumour PDL1 depletion specifically reduced tumour Chk2 content but not ATM, ATR, or Chk1 DDR proteins, enhanced Chk1 inhibitor (Chk1i) synthetic lethality in vitro in diverse human and murine tumour models, and improved Chk1i efficacy in vivo. Pharmacologic tumour PDL1 depletion with cefepime or ceftazidime replicated genetic tumour PDL1 depletion by reducing tumour Chk2, inducing Chk1i synthetic lethality in a tumour PDL1-dependent manner, and reducing in vivo tumour growth when combined with Chk1i. Conclusions: Our data challenge the prevailing surface PDL1 paradigm, elucidate important and previously unappreciated roles for tumour-intrinsic PDL1 in regulating the ATM/Chk2 DNA damage response axis and E3 ligase-mediated protein degradation, suggest tumour PDL1 as a biomarker for Chk1i efficacy, and support the rapid clinical potential of pharmacologic tumour PDL1 depletion to treat selected cancers. [ABSTRACT FROM AUTHOR]

The CHK2 protein regulates the cell division cycle and responds to DNA damage. Additionally, it facilitates the repair of DNA damage and maintains the integrity of its biological processes. Dysregulation of the CHK2 protein is associated with a predisposition to harmful diseases. The current research protocol was designed to identify novel hit molecules as CHK2 inhibitors and disrupt the normal biological function of the CHK2 protein via a fragment‐based drug discovery approach. The protocol involved generating fragments using the MacFrag tool, followed by a chemical similarity search utilizing RDKit to identify fragment molecules analogous to previously established CHK2 inhibitor scaffolds. The bioactive molecules were constructed using the Fragmenstein tool, followed by molecular docking simulations to investigate their binding affinity. In addition, pharmacokinetic properties were analyzed, and a molecular dynamics simulation study was conducted to assess the stability of selected compounds with CHK2 protein. Finally, five novel compounds were identified as excellent CHK2 inhibitors through the FBDD and show good binding interactions at active sites of CHK2 with beneficial ADMET properties. This research work presents novel CHK2 inhibitor molecules that have the potential to be utilized in drug discovery, serving as key leads for future advancements in healthcare industries and sectors. [ABSTRACT FROM AUTHOR]

Poly (ADP-ribose) polymerase (PARP) 1 and 2 enzymatic inhibitors (PARPi) are promising cancer treatments. But recently, their use has been hindered by unexplained severe anemia and treatment-related leukemia. In addition to enzymatic inhibition, PARPi also trap PARP1 and 2 at DNA lesions. Here we report that, unlike Parp2 −/− mice, which develop normally, mice expressing catalytically inactive Parp2 (E534A and Parp2 EA/EA ) succumb to Tp53 - and Chk2 -dependent erythropoietic failure in utero , mirroring Lig1 −/− mice. While DNA damage mainly activates PARP1, we demonstrate that DNA replication activates PARP2 robustly. PARP2 is selectively recruited and activated by 5′-phosphorylated nicks (5′p-nicks), including those between Okazaki fragments, resolved by ligase 1 (Lig1) and Lig3. Inactive PARP2, but not its active form or absence, impedes Lig1- and Lig3-mediated ligation, causing dose-dependent replication fork collapse, which is detrimental to erythroblasts with ultra-fast forks. This PARylation-dependent structural function of PARP2 at 5′p-nicks explains the detrimental effects of PARP2 inactivation on erythropoiesis, shedding light on PARPi-induced anemia and the selection for TP53/CHK2 loss. [Display omitted] • PARP2 is activated during normal erythroblastocyte replication by 5′p-nicks • Inactive PARP2 protein, but not the absence of PARP2, interferes with DNA replication • The presence of inactive PARP2 blocks erythropoiesis, leading to lethal anemia This work shows that the hematological toxicities associated with PARP inhibitors stem not from impaired PARP1 or PARP2 enzymatic activity but rather from the presence of inactive PARP2 protein. Mechanistically, these toxicities reflect a unique role of PARP2 at 5′-phosphorylated DNA nicks during DNA replication in erythroblasts. [ABSTRACT FROM AUTHOR]

Chemotherapy resistance remains a major challenge in the treatment of colorectal cancer (CRC). Therefore, it is crucial to develop novel strategies to sensitize cancer cells to chemotherapy. Here, the fringe family is screened to determine their contribution to chemotherapy resistance in CRC. It is found that RFNG depletion significantly sensitizes cancer cells to oxaliplatin treatment. Mechanistically, chemotherapy‐activated MAPK signaling induces ERK to phosphorylate RFNG Ser255 residue. Phosphorylated RFNG S255 (pS255) interacts with the nuclear importin proteins KPNA1/importin‐α1 and KPNB1/importin‐β1, leading to its translocation into the nucleus where it targets p53 and inhibits its phosphorylation by competitively inhibiting the binding of CHK2 to p53. Consequently, the expression of CDKN1A is decreased and that of SLC7A11 is increased, leading to the inhibition of apoptosis and ferroptosis. In contrast, phosphor‐deficient RFNG S225A mutant showed increased apoptosis and ferroptosis, and exhibited a notable response to oxaliplatin chemotherapy both in vitro and in vivo. It is further revealed that patients with low RFNG pS255 exhibited significant sensitivity to oxaliplatin in a patient‐derived xenograft (PDX) model. These findings highlight the crosstalk between the MAPK and p53 signaling pathways through RFNG, which mediates oxaliplatin resistance in CRC. Additionally, this study provides guidance for oxaliplatin treatment of CRC patients. [ABSTRACT FROM AUTHOR]

Giant cell glioblastoma often exhibits genome instability and is frequently associated with mutations in genes involved in DNA repair pathways including TP53 and DNA mismatch repair genes. Several germline mutations have been identified in giant cell glioblastoma, including mutations of MSH1 and MSH2, TP53, and POLE. We have documented a case of a germline mutation in CHEK2, another gene crucial to DNA repair, in a patient with giant cell glioblastoma. The CHEK2 mutation was inherited from the patient's father, who had a history of gastric cancer and renal cell carcinoma. In addition to the germline CHEK2 mutation, the giant cell glioblastoma exhibited a genome-wide loss of heterozygosity, a characteristic observed in a subset of giant cell glioblastomas. Additional mutations detected in the tumor included TP53, PTEN, and a PTPRZ1-MET fusion. This represents the first reported case of a CHEK2 germline mutation in giant cell glioblastoma, further supporting the significance of impaired DNA repair mechanisms in the development of this disease. [ABSTRACT FROM AUTHOR]

BackgroundMethodsResultsConclusionCheckpoint kinase 2 (CHEK2) and its regulated tumor protein p53 (TP53) have been correlated with osteogenic differentiation of osteoblast-like cells. Based on bioinformatics predictions, this study aims to investigate the effect of the CHEK2/TP53 axis on osteogenic differentiation of periodontal ligament stem cells (PDLSCs) and to explore the regulatory mechanism.PDLSCs were isolated from human impacted wisdom teeth, and they were cultured in normal medium (NM) or osteogenic medium (OM). Protein levels of CHEK2 and TP53 were examined using western blot analysis. Osteogenic differentiation ability of PDLSCs was analyzed by measuring marker proteins (RUNX2, OCN, and OSX), ALP activity, and ALP staining. Molecular interaction between NEDD4 like E3 ubiquitin protein ligase (NEDD4L) and CHEK2 was examined by ubiquitination and co-immunoprecipitation assays. Gain- and loss-of function assays of NEDD4L, CHEK2, and TP53 were performed to analyze their function in osteogenic differentiation of PDLSCs. A rat model of mandibular bone defect was generated for in vivo validation.NEDD4L was upregulated, while CHEK2 and TP53 were downregulated in PDLSCs cultured in OM. CHEK2 protected TP53 from degradation, while NEDD4L reduced CHEK2 protein level by ubiquitination modification. NEDD4L silencing reduced osteogenic differentiation ability of PDLSCs both in vitro and in vivo, which was restored by CHEK2 silencing. By contrast, CHEK2 overexpression blocked the osteogenic differentiation of PDLSCs in vitro.This study demonstrates that NEDD4L affects protein stability of the CHEK2/TP53 axis through ubiquitination modification, thus increasing osteogenic differentiation of PDLSCs. [ABSTRACT FROM AUTHOR]

Genomic instability is a core characteristic of cancer, often stemming from defects in DNA damage response (DDR) or increased replication stress. DDR defects can lead to significant genetic alterations, including changes in gene copy numbers, gene rearrangements, and mutations, which accumulate over time and drive the clonal evolution of cancer cells. However, these vulnerabilities also present opportunities for targeted therapies that exploit DDR deficiencies, potentially improving treatment efficacy and patient outcomes. The development of PARP inhibitors like Olaparib has significantly improved the treatment of cancers with DDR defects (e.g., BRCA1 or BRCA2 mutations) based on synthetic lethality. This achievement has spurred further research into identifying additional therapeutic targets within the DDR pathway. Recent progress includes the development of inhibitors targeting other key DDR components such as DNA-PK, ATM, ATR, Chk1, Chk2, and Wee1 kinases. Current research is focused on optimizing these therapies by developing predictive biomarkers for treatment response, analyzing mechanisms of resistance (both intrinsic and acquired), and exploring the potential for combining DDR-targeted therapies with chemotherapy, radiotherapy, and immunotherapy. This article provides an overview of the latest advancements in targeted anti-tumor therapies based on DDR and their implications for future cancer treatment strategies. [ABSTRACT FROM AUTHOR]

The article explores the research of Dr. Zhijian Chen, who has been recognized for his work on how DNA stimulates immunity. Dr. Chen's research focuses on the cGAS/STING pathway, which detects and eliminates infectious organisms by triggering an immune response. The article explains the process by which cGAS produces a molecule called cGAMP, which binds to STING and induces the production of interferon, a proinflammatory protein. It also discusses the regulation and termination of this pathway and its implications in autoimmune disorders, neurodegenerative diseases, and cancer. The article concludes by emphasizing the need for further research to better understand and target this pathway for therapeutic purposes. Additionally, the text provides a list of research articles that have contributed to our understanding of the STING pathway, including studies on its role in immune signaling, the activation of STING by cGAMP, and the surveillance of micronuclei by cGAS. It also mentions potential therapeutic strategies targeting the STING pathway, such as STING agonists and inhibitors of ENPP1, while acknowledging the potential risks and benefits of modulating this pathway in the context of cancer and autoimmune disorders. [Extracted from the article]

Therapy-related clonal hematopoiesis (t-CH) is defined as clonal hematopoiesis detected in individuals previously treated with chemotherapy and/or radiation therapy. With the increased use of genetic analysis in oncological care, the detection of t-CH among cancer patients is becoming increasingly common. t-CH arises through the selective bottleneck imposed by chemotherapies and potentially through direct mutagenesis from chemotherapies, resulting in a distinct mutational landscape enriched with mutations in DNA damage-response pathway genes such as TP53, PPM1D, and CHEK2. Emerging evidence sheds light on the mechanisms of t-CH development and potential strategies to mitigate its emergence. Due to its unique characteristics that predominantly affect cancer patients, t-CH has clinical implications distinct from those of CH in the general population. This Review discusses the potential mechanisms of t-CH development, its mutational landscape, mutant-drug relationships, and its clinical significance. We highlight the distinct nature of t-CH and call for intensified research in this field. [ABSTRACT FROM AUTHOR]

Purpose: This study seeks to contribute real-world data on the prevalence of BRCA1/2 and HRR gene mutations in prostate cancer. Methods: We compiled sequencing data of 197 cases of primary and metastatic prostate cancer, in which HRR mutation analysis was performed upon clinical request within the last 5 years. All cases were analyzed using a targeted NGS BRCAness multigene panel, including 8 HRR genes (ATM, BRCA1, BRCA2, CDK12, CHEK2, FANCA, HDAC2, PALB2). Results: Our findings reveal a prevalence of potentially targetable mutations based on FDA criteria of 20.8%, which is comparable to the literature. However, the frequency of targetable BRCA2 mutations within our cohort was lower than reported for mCRPC and ATM and CHEK2 mutations were more prevalent instead. Thus, while 20.8% (n = 38) of the cases meet the criteria for olaparib treatment per FDA approval, only 4.9% (n = 9) align with the eligibility criteria according to the EMA approval. Conclusion: This study offers valuable real-world insights into the landscape of BRCA1/2 and HRR gene mutations and the practical clinical management of HRR gene testing in prostate cancer, contributing to a better understanding of patient eligibility for PARPi treatment. [ABSTRACT FROM AUTHOR]

Checkpoint kinases 1 and 2 (CHK1 and CHK2) are enzymes that are involved in the control of DNA damage. At the present time, these enzymes are some of the most important targets in the fight against cancer since their inhibition produces cytotoxic effects in carcinogenic cells. This paper proposes the use of spirostans (Sp), natural compounds, as possible inhibitors of the enzymes CHK1 and CHK2 from an in silico analysis of a database of 155 molecules (S5). Bioinformatics studies of molecular docking were able to discriminate between 13 possible CHK1 inhibitors, 13 CHK2 inhibitors and 1 dual inhibitor for both enzymes. The administration, distribution, metabolism, excretion and toxicity (ADMETx) studies allowed a prediction of the distribution and metabolism of the potential inhibitors in the body, as well as determining the excretion routes and the appropriate administration route. The best inhibition candidates were discriminated by comparing the enzyme-substrate interactions from 2D diagrams and molecular docking. Specific inhibition candidates were obtained, in addition to studying the dual inhibitor candidate and observing their stability in dynamic molecular studies. In addition, Highest Occupied Molecular Orbital—Lowest Unoccupied Molecular Orbital (HOMO-LUMO) interactions were analyzed to study the stability of interactions between the selected enzymes and spirostans resulting in the predominant gaps from HOMOCHKs to LUMOSp (Highest Occupied Molecular Orbital of CHKs—Lowest Unoccupied Molecular Orbital of spirostan). In brief, this study presents the selection inhibitors of CHK1 and CHK2 as a potential treatment for cancer using a combination of molecular docking and dynamics, ADMETx predictons, and HOMO-LUMO calculation for selection. [ABSTRACT FROM AUTHOR]

Loss of function mutations in the checkpoint kinase gene CHEK2 are associated with increased risk of breast and other cancers. Most of the 3,188 unique amino acid changes that can result from non-synonymous single nucleotide variants (SNVs) of CHEK2, however, have not been tested for their impact on the function of the CHEK2-enocded protein (CHK2). One successful approach to testing the function of variants has been to test for their ability to complement mutations in the yeast ortholog of CHEK2, RAD53. This approach has been used to provide functional information on over 100 CHEK2 SNVs and the results align with functional assays in human cells and known pathogenicity. Here we tested all but two of the 4,887 possible SNVs in the CHEK2 open reading frame for their ability to complement RAD53 mutants using a high throughput technique of deep mutational scanning (DMS). Among the non-synonymous changes, 770 were damaging to protein function while 2,417 were tolerated. The results correlate well with previous structure and function data and provide a first or additional functional assay for all the variants of uncertain significance identified in clinical databases. Combined, this approach can be used to help predict the pathogenicity of CHEK2 variants of uncertain significance that are found in susceptibility screening and could be applied to other cancer risk genes. Author summary: Variations in gene sequences account for many of the phenotypic differences between individuals, including different susceptibilities to diseases like cancer. Individuals who inherit specific variants in the CHEK2 gene, for example, have increased risk of developing breast cancer and other cancers. These cancer-associated variants all abolish the normal activity of the CHEK2-encoded protein, a protein kinase called Chk2. Most of the CHEK2 variants found in individuals, however, have an unknown effect on the function of the Chk2 protein, and therefore an unknown potential role in cancer. This is because it is cumbersome to individually make and test each newly identified variant to see whether it affects protein function. Here we use an efficient version of a technique called deep mutational scanning to test nearly all possible CHEK2 single nucleotide variants for their impact on Chk2 protein function. Analyses of the resulting data indicate that it will be useful for developing models to predict the cancer risk in individuals who inherit any CHEK2 variants. This study also demonstrates a viable efficient approach to study variants of other genes, including other cancer related genes. [ABSTRACT FROM AUTHOR]

PURPOSE: Genetic susceptibility to nonsyndromic renal cell carcinoma (RCC) remains poorly understood, especially for different histological subtypes, as does variations in genetic predisposition in different populations. The objectives of this study were to identify risk genes for RCC in the Canadian population, investigate their clinical significance, and evaluate variations in germline pathogenic variants (PVs) among patients with RCC across the globe. MATERIALS AND METHODS: We conducted targeted sequencing of 19 RCC-related and 27 cancer predisposition genes for 960 patients with RCC from Canada and identified genes enriched in rare germline PVs in RCC compared with cancer-free controls. We combined our results with those reported for patients from Japan, the United Kingdom, and the United States to investigate PV variations in different populations. Furthermore, we evaluated the performance of referral criteria for genetic screening for including patients with rare PVs. RESULTS: We identified 39 germline PVs in 56 patients (5.8%) from the Canadian cohort. Compared with cancer-free controls, PVs in CHEK2 (odds ratio [OR], 4.8 [95% CI, 2.7 to 7.9], P = 3.94 × 10−5) and ATM (OR, 4.5 [95% CI, 2.0 to 8.7], P =.016) were significantly enriched in patients with clear cell, whereas PVs in FH (OR, 215.1 [95% CI, 64.4 to 597.8], P = 6.14 × 10−9) were enriched in patients with non-clear cell RCCs. PVs in BRCA1 , BRCA2 , and ATM were associated with metastasis (P =.003). Comparative analyses showed an enrichment of TP53 PVs in patients from Japan, of CHEK2 and ATM in patients from Canada, the United States and the United Kingdom, and of FH and BAP1 in the United States. CONCLUSION: CHEK2 , ATM , and FH are risk genes for RCC in the Canadian population, whereas PVs in BRCA1 / 2 and ATM are associated with risk of metastasis. Globally, clinical guidelines for genetic screening in RCC fail to include more than 70% of patients with rare germline PVs. This study investigates germline susceptibility and referral criteria for genetic screening for RCC [ABSTRACT FROM AUTHOR]

Background: In this article, we delineate a loosely selected cohort comprising patients with a history of early‐onset breast cancer and/or a familial occurrence of cancer. The aim of this study was to gain insights into the presence of breast cancer‐related gene variants in a population from a micro‐region in southern Brazil, specifically the Metropolitan Region of Curitiba. This area exhibits a highly genetically mixed population, mirroring the general characteristics of the Brazilian people. Methods: Comprehensive next‐generation sequencing (NGS) multigene panel testing was conducted on 12 patients from the region, utilizing three different library preparation methods. Results: Two pathogenic variants and one candidate pathogenic variant were identified: BRCA2 c.8878C>T, p.Gln2960Ter; CHEK2 c.1100del, p.Thr367Metfs15, and BRCA2 c.3482dup, p.Asp1161Glufs3. Conclusion: BRCA2 c.3482dup, a novel candidate pathogenic variant, previously unpublished, is reported. The prevalence of pathogenic variants in this small cohort is similar to that described in the literature. All different library preparation methods were equally proficient in enabling the detection of these variants. [ABSTRACT FROM AUTHOR]

CHEK2 is considered to be involved in homologous recombination repair (HRR). Individuals who have germline pathogenic variants (gPVs) in CHEK2 are at increased risk to develop breast cancer and likely other primary cancers. PARP inhibitors (PARPi) have been shown to be effective in the treatment of cancers that present with HRR deficiency—for example, caused by inactivation of BRCA1/2. However, clinical trials have shown little to no efficacy of PARPi in patients with CHEK2 gPVs. Here, we show that both breast and non-breast cancers from individuals who have biallelic gPVs in CHEK2 (germline CHEK2 deficiency) do not present with molecular profiles that fit with HRR deficiency. This finding provides a likely explanation why PARPi therapy is not successful in the treatment of CHEK2 -deficient cancers. [ABSTRACT FROM AUTHOR]

Nature provides us with a rich source of compounds with a wide range of applications, including the creation of innovative drugs. Despite advancements in chemically synthesized therapeutics, natural compounds are increasingly significant, especially in cancer treatment, a leading cause of death globally. One promising approach involves the use of natural inhibitors of checkpoint kinase 2 (Chk2), a critical regulator of DNA repair, cell cycle arrest, and apoptosis. Chk2's activation in response to DNA damage can lead to apoptosis or DNA repair, influencing glycolysis and mitochondrial function. In cancer therapy, inhibiting Chk2 can disrupt DNA repair and cell cycle progression, promoting cancer cell death and enhancing the efficacy of radiotherapy and chemotherapy. Additionally, Chk2 inhibitors can safeguard non-cancerous cells during these treatments by inhibiting p53-dependent apoptosis. Beyond oncology, Chk2 inhibition shows potential in treating hepatitis C virus (HCV) infections, as the virus relies on Chk2 for RNA replication in neurodegenerative diseases like amyotrophic lateral sclerosis (ALS), in which DNA damage plays a crucial role. Plant-derived Chk2 inhibitors, such as artemetin, rhamnetin, and curcumin, offer a promising future for treating various diseases with potentially milder side effects and broader metabolic impacts compared to conventional therapies. The review aims to underscore the immense potential of natural Chk2 inhibitors in various therapeutic contexts, particularly in oncology and the treatment of other diseases involving DNA damage and repair mechanisms. These natural Chk2 inhibitors hold significant promise for revolutionizing the landscape of cancer treatment and other diseases. Further research into these compounds could lead to the development of innovative therapies that offer hope for the future with fewer side effects and enhanced efficacy. [ABSTRACT FROM AUTHOR]

The subset of ovarian cancer (OC) diagnosed ≤ 30yo represents a distinct subgroup exhibiting disparities from late-onset OC in many aspects, including indefinite germline cancer predisposition. We performed DNA/RNA-WES with HLA-typing, PRS assessment and survival analysis in 123 early-onset OC-patients compared to histology/stage-matched late-onset and unselected OC-patients, and population-matched controls. Only 6/123(4.9%) early-onset OC-patients carried a germline pathogenic variant (GPV) in high-penetrance OC-predisposition genes. Nevertheless, our comprehensive germline analysis of early-onset OC-patients revealed two divergent trajectories of potential germline susceptibility. Firstly, overrepresentation analysis highlighted a connection to breast cancer (BC) that was supported by the CHEK2 GPV enrichment in early-onset OC(p = 1.2 × 10–4), and the presumably BC-specific PRS313, which successfully stratified early-onset OC-patients from controls(p = 0.03). The second avenue pointed towards the impaired immune response, indicated by LY75-CD302 GPV(p = 8.3 × 10–4) and diminished HLA diversity compared with controls(p = 3 × 10–7). Furthermore, we found a significantly higher overall GPV burden in early-onset OC-patients compared to controls(p = 3.8 × 10–4). The genetic predisposition to early-onset OC appears to be a heterogeneous and complex process that goes beyond the traditional Mendelian monogenic understanding of hereditary cancer predisposition, with a significant role of the immune system. We speculate that rather a cumulative overall GPV burden than specific GPV may potentially increase OC risk, concomitantly with reduced HLA diversity. [ABSTRACT FROM AUTHOR]

Objective Patients and methods Results Conclusion To investigate alterations of homologous recombination repair (HRR) and especially BReast CAncer 1/2 (BRCA1/2) gene on overall survival (OS). Moreover, to explore the effect of inhibition of poly(ADP‐ribose)‐polymerase (PARPi) as systemic therapy for metastatic castration‐resistant prostate cancer (mCRPC).Of all HRR‐screened patients with metastatic prostate cancer, baseline characteristics were sampled. Kaplan–Meier estimates and multivariable Cox regression models predicted the effect of HRR/BRCA1/2 alterations on OS.Of 196 eligible patients, 61 (31%) harboured any HRR and 40 (20%) BRCA1/2 alterations. Of HRR alterations, 40 (66%) vs six (10%) vs five (8.2%) vs four (6.6%) vs two (3.3%) vs four (6.6%) were BRCA1/2 vs Ataxia‐telangiectasia mutated kinase (ATM) vs checkpoint kinase 2 (CHEK2) vs cyclin‐dependent kinase 12 (CDK12) vs Fanconi anaemia complementation Group A (FANCA) vs positive for other mutations. Of these, 30% received a PARPi. OS differed significantly between HRR‐positive vs ‐negative patients. Specifically in hormone‐sensitive prostate cancer, the median OS was 63 (HRR positive) vs 57 (BRCA1/2 positive) vs 113 months (HRR negative) (P ≤ 0.01). In mCRPC, OS was 42 (HRR positive) vs 41 (BRCA1/2 positive) vs 70 months (HRR negative) (P ≤ 0.01). HRR and BRCA1/2 alterations were associated with worse OS after multivariable adjustment. Finally, patients with mCRPC with BRCA1/2 mutation treated without PARPi harboured worse OS than patients with BRCA1/2 mutation and PARPi therapy (median OS: 33 vs 48 months, P < 0.03).Incidence of HRR alteration in a clinical real‐world setting is high when using blood‐ and tissue‐based tests. Patients with HRR/BRCA alterations have worse outcomes resulting in significant OS differences between HRR/BRCA‐positive patients with mCRPC with and without PARPi usage vs HRR/BRCA‐negative patients. [ABSTRACT FROM AUTHOR]

Citrinin (CIT), a polyketide mycotoxin produced by Penicillium, Aspergillus, and Monascus species, is a contaminant that has been found in various food commodities and was also detected in house dust. Several studies showed that CIT can impair the kidney, liver, heart, immune, and reproductive systems in animals by mechanisms so far not completely elucidated. In this study, we investigated the CIT mode of action on two human tumor cell lines, HepG2 (hepatocellular carcinoma) and A549 (lung adenocarcinoma). Cytotoxic concentrations were determined using an MTT proliferation assay. The genotoxic effect of sub-IC50 concentrations was investigated using the alkaline comet assay and the impact on the cell cycle using flow cytometry. Additionally, the CIT effect on the total amount and phosphorylation of two cell-cycle-checkpoint proteins, the serine/threonine kinase Chk2 and Fanconi anemia (FA) group D2 (FANCD2), was determined by the cell-based ELISA. The data were analyzed using GraphPad Prism statistical software. The CIT IC50 for HepG2 was 107.3 µM, and for A549, it was >250 µM. The results showed that sensitivity to CIT is cell-type dependent and that CIT in sub-IC50 and near IC50 induces significant DNA damage and cell-cycle arrest in the G2/M phase, which is related to the increase in total and phosphorylated Chk2 and FANCD2 checkpoint proteins in HepG2 and A549 cells. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) risks imparted by CHEK2 c.1100delC ("1100delC") germline pathogenic/likely pathogenic variant (GPV) are 20–30%, compared to CHEK2 c.470T>C ("I157T") GPV with <20%, leading to different breast screening recommendations through MRI. We compared cancer risk management (CRM) across these two GPVs. Study participants were adult females with an 1100delC or I157T GPV drawn from the Inherited Cancer Registry (ICARE) across the United States. Cancer history, clinical characteristics, and CRM were compared using chi-squared tests, t-tests, and logistic regression. Of 150 CHEK2 carriers, 40.7% had BC, with a mean age of 50. Comparing 1100delC and I157T GPVs, there were no differences in rates of (1) breast MRI among those with (65.2% versus 55.6% of 23 and 9; p = 0.612) and without (44.0% versus 44.8% of 50 and 29; p = 0.943) BC; (2) risk-reducing mastectomy among those with (50% versus 38.9% of 46 and 15; p = 0.501) and without (13.8% versus 6.5% of 58 and 31; p = 0.296) BC; and (3) risk-reducing salpingo-oophorectomy among those with (24.2% versus 22.2% of 45 and 18; p = 0.852) and without (17.5% versus 16.7% of 57 and 30; p = 0.918) BC. The results suggest over-screening with breast MRI among CHEK2 I157T GPV carriers and possible overuse of risk-reducing surgeries among CHEK2 carriers. [ABSTRACT FROM AUTHOR]

BackgroundBreast cancer (BC) patients with a germline CHEK2 c.1100delC variant have an increased risk of contralateral BC (CBC) and worse BC-specific survival (BCSS) compared to non-carriers.AimTo assessed the associations of CHEK2 c.1100delC, radiotherapy, and systemic treatment with CBC risk and BCSS.MethodsAnalyses were based on 82,701 women diagnosed with a first primary invasive BC including 963 CHEK2 c.1100delC carriers; median follow-up was 9.1 years. Differential associations with treatment by CHEK2 c.1100delC status were tested by including interaction terms in a multivariable Cox regression model. A multi-state model was used for further insight into the relation between CHEK2 c.1100delC status, treatment, CBC risk and death.ResultsThere was no evidence for differential associations of therapy with CBC risk by CHEK2 c.1100delC status. The strongest association with reduced CBC risk was observed for the combination of chemotherapy and endocrine therapy [HR (95% CI): 0.66 (0.55-0.78)]. No association was observed with radiotherapy. Results from the multi-state model showed shorter BCSS for CHEK2 c.1100delC carriers versus non-carriers also after accounting for CBC occurrence [HR (95% CI): 1.30 (1.09-1.56)].ConclusionSystemic therapy was associated with reduced CBC risk irrespective of CHEK2 c.1100delC status. Moreover, CHEK2 c.1100delC carriers had shorter BCSS, which appears not to be fully explained by their CBC risk.

PURPOSE: To estimate the risk of contralateral breast cancer (CBC) among women with germline pathogenic variants (PVs) in ATM, BRCA1, BRCA2, CHEK2, and PALB2. METHODS: The study population included 15,104 prospectively followed women within the CARRIERS study treated with ipsilateral surgery for invasive breast cancer. The risk of CBC was estimated for PV carriers in each gene compared with women without PVs in a multivariate proportional hazard regression analysis accounting for the competing risk of death and adjusting for patient and tumor characteristics. The primary analyses focused on the overall cohort and on women from the general population. Secondary analyses examined associations by race/ethnicity, age at primary breast cancer diagnosis, menopausal status, and tumor estrogen receptor (ER) status. RESULTS: Germline BRCA1, BRCA2, and CHEK2 PV carriers with breast cancer were at significantly elevated risk (hazard ratio > 1.9) of CBC, whereas only the PALB2 PV carriers with ER-negative breast cancer had elevated risks (hazard ratio, 2.9). By contrast, ATM PV carriers did not have significantly increased CBC risks. African American PV carriers had similarly elevated risks of CBC as non-Hispanic White PV carriers. Among premenopausal women, the 10-year cumulative incidence of CBC was estimated to be 33% for BRCA1, 27% for BRCA2, and 13% for CHEK2 PV carriers with breast cancer and 35% for PALB2 PV carriers with ER-negative breast cancer. The 10-year cumulative incidence of CBC among postmenopausal PV carriers was 12% for BRCA1, 9% for BRCA2, and 4% for CHEK2. CONCLUSION: Women diagnosed with breast cancer and known to carry germline PVs in BRCA1, BRCA2, CHEK2, or PALB2 are at substantially increased risk of CBC and may benefit from enhanced surveillance and risk reduction strategies.

Digestive-system cancers represent major threats to human health; however, the mechanisms underlying tumorigenesis and radiochemotherapy resistance have remained elusive. Therefore, an urgent need exists for identifying key drivers of digestive system tumorigenesis and novel targeted therapeutics. The checkpoint kinase 2 (Chk2) regulates cell-cycle progression, and Chk2 dysregulation or Chk2 mutations can lead to the development of various cancers, which makes Chk2 an important research topic. This review summarizes the roles of Chk2 in DNA-damage responses, cell-cycle regulation, autophagy, and homeostasis maintenance. We describe relationships between tumorigenesis and cell-cycle dysregulation induced by Chk2 mutations. In addition, we summarize evidence indicating that Chk2 can serve as a novel therapeutic target, based on its contributions to radiochemotherapy-resistance reversion and progress made in developing antitumor agents against Chk2. The prevailing evidence supports the conclusion that further research on Chk2 will provide a deeper understanding of digestive-system tumorigenesis and should suggest novel therapeutic targets.

Relatively little is known about experiences of individuals with a pathogenic variant in a moderately penetrant breast cancer gene, particularly those without a personal history of cancer. The WISDOM trial is testing a model of risk-based breast cancer screening that integrates genomic (nine genes and polygenic risk) and other risk factors. In the context of an embedded Ethical, Legal, and Social Implications (ELSI) study of WISDOM, we conducted qualitative interviews at two timepoints post-result disclosure with 22 ATM and CHEK2 carriers. Results disclosure and interview recordings were transcribed and analyzed using a grounded theory analysis framework. We found that participants minimized the significance of their results in comparison to BRCA; were surprised but not alarmed by the results in the absence of family history; did not fundamentally change their perception of their breast cancer risk despite the new genomic information; exhibited variable responses to WISDOM's screening and risk reduction recommendations; and shared test results with family but did not strongly encourage cascade testing. Participants viewed the results as having limited utility and responded accordingly. Our study offers important insights into how genetic test results for moderate-risk genes are received, understood, and acted upon in population screening context.

In this study, we report the mutational profiles, pathogenicity, and their association with different clinicopathologic and sociogenetic factors in patients with Pashtun ethnicity for the first time. A total of 19 FFPE blocks of invasive ductal carcinoma (IDC) from the Breast Cancer (BC) tissue and 6 normal FFPE blocks were analyzed by whole-exome sequencing (WES). Various somatic and germline mutations were identified in cancer-related genes, i.e., ATM, CHEK2, PALB2, and XRCC2. Among a total of 18 mutations, 14 mutations were somatic and 4 were germline. The ATM gene exhibited the maximum number of mutations (11/18), followed by CHEK2 (3/18), PALB2 (3/18), and XRCC2 (1/18). Except one frameshift deletion, all other 17 mutations were nonsynonymous single-nucleotide variants (SNVs). SIFT prediction revealed 7/18 (38.8%) mutations as deleterious. PolyPhen-2 and MutationTaster identified 5/18 (27.7%) mutations as probably damaging and 10/18 (55.5%) mutations as disease-causing, respectively. Mutations like PALB2 p.Q559R (6/19; 31.5%), XRCC2 p.R188H (5/19; 26.31%), and ATM p.D1853N (4/19; 21.05%) were recurrent mutations and proposed to have a biomarker potential. The protein network prediction was performed using GeneMANIA and STRING. ISPRED-SEQ indicated three interaction site mutations which were further used for molecular dynamic simulation. An average increase in the radius of gyration was observed in all three mutated proteins revealing their perturbed folding behavior. Obtained SNVs were further correlated with various parameters related to the clinicopathological status of the tumors. Three mutation positions (ATM p. D1853N, CHEK2 p.M314I, and PALB2 p.T1029S) were found to be highly conserved. Finally, the wild- and mutant-type proteins were screened for two drugs: elagolix (DrugBank ID: DB11979) and LTS0102038 (a triterpenoid, isolated from the anticancer medicinal plant Fagonia indica). Comparatively, a higher number of interactions were noted for normal ATM with both compounds, as compared to mutants. [ABSTRACT FROM AUTHOR]

This document provides concise summaries of several research articles related to gynecologic cancers. The articles cover a range of topics including the use of medical cannabis for endometrial cancer treatment, radiation therapy for endometrial cancer, the incidence and mortality rates of uterine, HPV-associated, and ovarian cancers in Taiwan, and the role of predictive models and diagnostic tools in gynecologic oncology. These summaries offer valuable insights for library patrons conducting research on these specific topics, providing culturally sensitive and diverse perspectives on the latest advancements in the field of gynecologic oncology. [Extracted from the article]

Menopausal status affects the prognoses and consequences of breast cancer. Therefore, this retrospective study aimed to reveal the molecular variation profile differences in breast cancer patients according to their menopausal status, with the hypothesis that the molecular variation profiles will be different at premenopausal and postmenopausal ages. Breast cancer patients (n = 254) who underwent molecular subtyping and QIAseq Human Breast Cancer NGS Panel screening between 2018 and 2022 were evaluated retrospectively. Their menopausal status was defined by age, and those aged 50 years and above were considered postmenopausal. Of the subjects, 58.66% (n = 149) were premenopausal and 41.34% (n = 105) were postmenopausal. The mean age at the time of diagnosis for all patients was 49.31 ± 11.19 years, with respective values of 42.11 ± 5.51 and 59.54 ± 9.01 years for the premenopausal and postmenopausal groups, respectively (p = 0.000). Among premenopausal patients, the percentages of patients in BCa subtypes (luminal A, luminal B-HER2(−), luminal B-HER2(+), HER2 positive, and triple-negative) were determined to be 34.90%, 8.05%, 26.17%, 10.74%, and 20.13%, respectively, while in the postmenopausal group, these values were 39.05%, 16.19%, 24.76%, 6.67%, and 13.33%, respectively (p > 0.05). Considering menopausal status, the distribution of hormone receptors in premenopausal patients was ER(+)/PgR(+) 63.76%, ER(−)/PgR(−) 23.49%, ER(+)/PgR(−) 10.74%, and ER(−)/PgR(+) 2.01%, respectively, while in postmenopausal women, this distribution was observed to be 74.29%, 23.81%, 1.90% and 0.00% in the same order (p = 0.008). The most frequently mutated gene was TP53 in 130 patients (51.18%), followed by PIK3CA in 85 patients (33.46%), BRCA2 and NF1 in 56 patients (22.05%), PTEN in 54 patients (21.26%), and ATR and CHEK2 in 53 patients (20.87%). TP53, PIK3CA, NF1, BRCA2, PTEN, and CHEK2 mutations were more frequently observed in premenopausal patients, while TP53, PIK3CA, BRCA2, BRCA1, and ATR mutations in postmenopausal patients. These findings contribute to a deeper understanding of the underlying causes of breast cancer with respect to menopausal status. This study is the first from Turkey that reflects the molecular subtyping and somatic mutation profiles of breast cancer patients according to menopausal status. [ABSTRACT FROM AUTHOR]

Background: Germline pathogenic variants in CHEK2 are associated with a moderate increase in the lifetime risk for breast cancer. Increased risk for other cancers, including non-medullary thyroid cancer (NMTC), has also been suggested. To date, data implicating CHEK2 variants in NMTC predisposition primarily derive from studies within Poland, driven by a splice site variant (c.444 + 1G>A) that is uncommon in other populations. In contrast, the predominant CHEK2 variants in non-Polish populations are c.1100del and c.470T>C/p.I157T, representing 61.1% and 63.8%, respectively, of all CHEK2 pathogenic variants in two large U.S.-based commercial laboratory datasets. To further delineate the impact of common CHEK2 variants on thyroid cancer, we aimed to investigate the association of three CHEK2 founder variants (c.444 + 1G>A, c.1100del, and c.470T>C/p.Ile157Thr) on NMTC susceptibility in three groups of unselected NMTC patients. Methods: The presence of three CHEK2 founder variants was assessed within three groups: (1) 1544 NMTC patients (and 1593 controls) from previously published genome-wide association study (GWAS) analyses, (2) 789 NMTC patients with germline exome sequencing (Oncology Research Information Exchange Network [ORIEN] Avatar), and (3) 499 NMTC patients with germline sequence data available in The Cancer Genome Atlas (TCGA). A case–control study design was utilized with odds ratios (ORs) calculated by comparison of all three groups with the Ohio State University GWAS control group. Results: The predominant Polish variant (c.444 + 1G>A) was present in only one case. The proportion of patients with c.1100del was 0.92% in the GWAS group, 1.65% in the ORIEN Avatar group, and 0.80% in the TCGA group. The ORs (with 95% confidence intervals [CIs]) for NMTC associated with c.1100del were 1.71 (0.73–4.29), 2.64 (0.95–7.63), and 2.5 (0.63–8.46), respectively. The proportion of patients with c.470T>C/p.I157T was 0.91% in the GWAS group, 0.76% in the ORIEN Avatar group, and 0.80% in the TCGA group, respectively. The ORs (with CIs) for NMTC associated with c.470T>C/p.I157T were 1.75 (0.74–4.39), 1.52 (0.42–4.96), and 2.31 (0.58–7.90), respectively. Conclusions: Our analyses of unselected patients with NMTC suggest that CHEK2 variants c.1100del and c.470T>C/p.I157T have only a modest impact on thyroid cancer risk. These results provide important information for providers regarding the relatively low magnitude of thyroid cancer risk associated with these CHEK2 variants. [ABSTRACT FROM AUTHOR]

Breast cancer is a complex disease with diverse molecular subtypes, making treatment selection and outcome prediction challenging. Advances in molecular research have provided insights into the cellular pathways involved in breast tumor progression, leading to the identification of diagnostic markers and innovative therapeutic approaches. Endocrine therapy is the primary treatment for hormone-receptor-positive breast cancers, but resistance can develop through various mechanisms. Identifying targets involved in endocrine therapy resistance can improve treatment efficacy. Epigenetic modifications, such as mRNA modifications and histone modifications, also play a role in breast cancer oncogenesis. The androgen receptor has different roles in different breast cancer subtypes, and targeting it has shown promise in improving treatment outcomes. Triple-negative breast cancer, characterized by the absence of hormone receptors and HER2 expression, is typically treated with chemotherapy, but immunotherapy has shown promise. Claudin-low breast cancer, a subtype of triple-negative breast cancer, is associated with poor prognosis, and targeting cytochrome P4501B1 and fibronectin type III domain-containing protein 5 may be potential therapeutic strategies. Aberrations in Golgi apparatus functioning have been linked to breast cancer initiation and progression, and targeting Golgi-associated proteins may offer treatment options. Overall, this special issue explores various research areas related to molecular research and treatment of breast cancer, providing valuable insights into the disease. [Extracted from the article]

Splicing is controlled by a large set of regulatory elements (SREs) including splicing enhancers and silencers, which are involved in exon recognition. Variants at these motifs may dysregulate splicing and trigger loss‐of‐function transcripts associated with disease. Our goal here was to study the alternatively spliced exons 8 and 10 of the breast cancer susceptibility gene CHEK2. For this purpose, we used a previously published minigene with exons 6–10 that produced the expected minigene full‐length transcript and replicated the naturally occurring events of exon 8 [Δ(E8)] and exon 10 [Δ(E10)] skipping. We then introduced 12 internal microdeletions of exons 8 and 10 by mutagenesis in order to map SRE‐rich intervals by splicing assays in MCF‐7 cells. We identified three minimal (10‐, 11‐, 15‐nt) regions essential for exon recognition: c.863_877del [ex8, Δ(E8): 75%] and c.1073_1083del and c.1083_1092del [ex10, Δ(E10): 97% and 62%, respectively]. Then 87 variants found within these intervals were introduced into the wild‐type minigene and tested functionally. Thirty‐eight of them (44%) impaired splicing, four of which (c.883G>A, c.883G>T, c.884A>T, and c.1080G>T) induced negligible amounts (<5%) of the minigene full‐length transcript. Another six variants (c.886G>A, c.886G>T, c.1075G>A, c.1075G>T, c.1076A>T, and c.1078G>T) showed significantly strong impacts (20–50% of the minigene full‐length transcript). Thirty‐three of the 38 spliceogenic variants were annotated as missense, three as nonsense, and two as synonymous, underlying the fact that any exonic change is capable of disrupting splicing. Moreover, c.883G>A, c.883G>T, and c.884A>T were classified as pathogenic/likely pathogenic variants according to ACMG/AMP (American College of Medical Genetics and Genomics/Association for Molecular Pathology)‐based criteria. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

Hereditary breast and ovarian cancer (HBOC) syndrome is responsible for approximately 10% of breast cancers (BCs). The HBOC gene panel includes both high-risk genes, i.e., a four times higher risk of BC (BRCA1, BRCA2, PALB2, CDH1, PTEN, STK11 and TP53), and moderate-risk genes, i.e., a two to four times higher risk of BC (BARD1, CHEK2, RAD51C, RAD51D and ATM). Pathogenic germline variants (PGVs) in HBOC genes confer an absolute risk of BC that changes according to the gene considered. We illustrate and compare different BC risk estimation models, also describing their limitations. These models allow us to identify women eligible for genetic testing and possibly to offer surgical strategies for primary prevention, i.e., risk-reducing mastectomies and salpingo-oophorectomies. [ABSTRACT FROM AUTHOR]

Inherited mutations in the CHEK2 gene have been associated with an increased lifetime risk of developing breast cancer (BC). We aim to identify in the study population the prevalence of mutations in the CHEK2 gene in diagnosed BC patients, evaluate the phenotypic characteristics of the tumor and family history, and predict the deleteriousness of the variants of uncertain significance (VUS). A genetic study was performed, from May 2016 to April 2020, in 396 patients diagnosed with BC at the University Hospital Lozano Blesa of Zaragoza, Spain. Patients with a genetic variant in the CHEK2 gene were selected for the study. We performed a descriptive analysis of the clinical variables, a bibliographic review of the variants, and a cosegregation study when possible. Moreover, an in-depth bioinformatics analysis of CHEK2 VUS was carried out. We identified nine genetic variants in the CHEK2 gene in 10 patients (two pathogenic variants and seven VUS). This supposes a prevalence of 0.75% and 1.77%, respectively. In all cases, there was a family history of BC in first-and/or second-degree relatives. We carried out a cosegregation study in two families, being positive in one of them. The bioinformatics analyses predicted the pathogenicity of six of the VUS. In conclusion, CHEK2 mutations have been associated with an increased risk for BC. This risk is well-established for foundation variants. However, the risk assessment for other variants is unclear. The incorporation of bioinformatics analysis provided supporting evidence of the pathogenicity of VUS. [ABSTRACT FROM AUTHOR]

Approximately 5 to 15% of nonmedullary thyroid cancers (NMTC) present in a familial form (familial nonmedullary thyroid cancers [FNMTC]). The genetic basis of FNMTC remains largely unknown, representing a limitation for diagnostic and clinical management. Recently, germline mutations in DNA repair-related genes have been described in cases with thyroid cancer (TC), suggesting a role in FNMTC etiology. Here, two FNMTC families were studied, each with two members affected with TC. Ninety-four hereditary cancer predisposition genes were analyzed through next-generation sequencing, revealing two germline CHEK2 missense variants (c.962A > C, p.E321A and c.470T > C, p.I157T), which segregated with TC in each FNMTC family. p.E321A, located in the CHK2 protein kinase domain, is a rare variant, previously unreported in the literature. Conversely, p.I157T, located in CHK2 forkhead-associated domain, has been extensively described, having conflicting interpretations of pathogenicity. CHK2 proteins (WT and variants) were characterized using biophysical methods, molecular dynamics simulations, and immunohistochemistry. Overall, biophysical characterization of theseCHK2variants showed that they have compromised structural and conformational stability and impaired kinase activity, compared to the WT protein. CHK2 appears to aggregate into amyloid-like fibrils in vitro, which opens future perspectives toward positioning CHK2 in cancer pathophysiology. CHK2 variants exhibited higher propensity for this conformational change, also displaying higher expression in thyroid tumors. The present findings support the utility of complementary biophysical and in silico approaches toward understanding the impact of genetic variants in protein structure and function, improving the current knowledge on CHEK2 variants' role in FNMTC genetic basis, with prospective clinical translation. [ABSTRACT FROM AUTHOR]

Allyl isothiocyanate (AITC) is abundant in cruciferous vegetables and it present pharmacological activity including anticancer activity in many types of human cancer cells in vitro and in vivo. Currently, no available information to show AITC affecting DNA damage and repair‐associated protein expression in human gastric cancer cells. Therefore, in the present studies, we investigated AITC‐induced cytotoxic effects on human gastric cancer in AGS and SNU‐1 cells whether or not via the induction of DNA damage and affected DNA damage and repair associated poteins expressions in vitro. Cell viability and morphological changes were assayed by flow cytometer and phase contrast microscopy, respectively, the results indicated AITC induced cell morphological changes and decreased total viable cells in AGS and SNU‐1 cells in a dose‐dependently. AITC induced DNA condensation and damage in a dose‐dependently which based on the cell nuclei was stained by 4′, 6‐diamidino‐2‐phenylindole present in AGS and SNU‐1 cells. DNA damage and repair associated proteins expression in AGS and SNU‐1 cells were measured by Western blotting. The results indicated AITC decreased nuclear factor erythroid 2‐related factor 2 (NRF2), heme oxygenase‐1 (HO‐1), glutathione, and catalase, but increased superoxide dismutase (SOD (Cu/Zn)), and nitric oxide synthase (iNOS) in AGS cells, however, in SNU‐1 cells are increased HO‐1. AITC increased DNA‐dependent protein kinase (DNA‐PK), phosphorylation of gamma H2A histone family member X on Ser139 (γH2AXpSer139), and heat shock protein 90 (HSP90) in AGS cells. AITC increased DNA‐PK, mediator of DNA damage checkpoint protein 1 (MDC1), γH2AXpSer139, topoisomerase II alpha (TOPIIα), topoisomerase II beta (TOPIIβ), HSP90, and heat shock protein 70 (HSP70) in SNU‐1 cells. AITC increased p53, p53pSer15, and p21 but decreased murine double minute 2 (MDM2)pSer166 and O6‐methylguanine‐DNA methyltransferase (MGMT) in AGS cells; however, it has a similar effect of AITC except increased ataxia telangiectasia and Rad3‐related protein (ATR)pSer428, checkpoint kinase 1 (CHK1), and checkpoint kinase 2 (CHK2) in SNU‐1 cells. Apparently, both cell responses to AITC are different, nonetheless, all of these observations suggest that AITC inhibits the growth of gastric cancer cells may through induction off DNA damage in vitro. [ABSTRACT FROM AUTHOR]

False-positive ctDNA results do not explain lack of efficacy for PARPi in patients with ATMm and CHEK2m CRPC. [ABSTRACT FROM AUTHOR]

The article presents the discussion on efficacy of poly (ADP-ribose) polymerase inhibitors in treating breast cancer with BRCA1 or BRCA2 mutations and evaluates their potential for cancers with homologous recombination deficiencies, including those with CHEK2 mutations. Topics include the role of synthetic lethality in targeting BRCA-deficient tumors, clinical trial results for PARP inhibitors; and the bioinformatics analysis of genomic markers in tumors with CHEK2 mutations.

Current National Comprehensive Cancer Network ® (NCCN ®) guidelines for Colorectal Genetic/Familial High-Risk Assessment provide limited guidance for genetic testing for individuals with already diagnosed hereditary cancer conditions. We are presenting the case of a 36-year-old woman who was diagnosed with Lynch Syndrome at age 23 after genetic testing for a familial variant (c.283del) in the MLH1 gene. The patient had a previous history of Hodgkin Lymphoma at the time of familial variant testing, and she would later develop stage IIIa cecal adenocarcinoma at age 33 and metastatic papillary thyroid carcinoma at age 35. The patient's family history included a first-degree relative who was diagnosed with colorectal cancer at age 39, multiple second-degree relatives with colorectal, endometrial, and stomach cancer, and third and fourth-degree relatives with breast cancer. In light of her personal and family history, a comprehensive cancer panel was recommended. This panel found a second hereditary cancer predisposition syndrome: a likely pathogenic variant (c. 349 A > G) in the CHEK2 gene. This specific CHEK2 variant was recently reported to confer a moderately increased risk for breast cancer. The discovery of this second cancer predisposition syndrome had important implications for the patient's screening and risk management. While uncommon, the possibility of an individual having multiple cancer predisposition syndromes is important to consider when evaluating patients and families for hereditary cancer, even when a familial variant has been identified. [ABSTRACT FROM AUTHOR]

Simple Summary: CHK2 has functions in DNA damage repair. Germline CHEK2 mutations impair these functions, increasing the risk of PTC. The aim of this study was to determine whether CHK2 and p53 expression in patients with a germline CHEK2 mutation in tumor tissue can serve as a prognostic marker for papillary thyroid cancer (PTC), and whether copy number aberrations in CHEK2 and TP53 correlate with the course of PTC. This study included 156 patients with PTC who had been selected from a group of 1547 people previously tested for the presence of CHEK2 mutations in their peripheral blood. Higher CHK2 expression was associated with poorer treatment responses and disease outcomes in PTC patients. Higher CHK2 expression and positive p53 together with a TP53 deletion could have potential as a prognostic marker of unfavorable disease outcomes in patients with germline truncating mutations in CHEK2. The aim of this study was to determine whether the expression of CHK2 and p53 in tumor tissue in carriers of germline CHEK2 mutations can serve as a prognostic marker for PTC, and whether CHEK2 and TP53 copy numbers correlates with the course of PTC disease. This study included 156 PTC patients previously tested for the presence of CHEK2. Clinicopathological features, treatment response, disease outcome, and germline mutation status of the CHEK2 gene were assessed with respect to CHK2 and p53 expression, and CHEK2 and TP53 gene copy statuses. In patients with and without a germline mutation in CHEK2 and with higher CHK2 expression, the chances of an excellent treatment response and no evidence of disease were lower than in patients without or with lower CHK2 expression. TP53 deletion was associated with angioinvasion. In patients with a truncating mutation, the chance of a CHEK2 deletion was higher than in patients with WT CHEK2 alone or those with WT CHEK2 and with the missense I157T mutation. Higher CHK2 expression was associated with poorer treatment responses and disease outcomes. Higher CHK2 expression and positive p53 together with a TP53 deletion could be a prognostic marker of unfavorable disease outcomes in patients with germline truncating mutations in CHEK2. [ABSTRACT FROM AUTHOR]

PARP (poly(ADP-ribose) polymerase) inhibitors have demonstrated promising clinical activity in multiple homologous recombination (HR) deficiency tumors. However, glioblastoma (GBM) patients have obtained little benefit from PARP inhibitors alone. PARP inhibition shows considerable promise when used together with other therapeutic agents. Thus, novel combination therapies may enhance PARP inhibitor efficacy and overcome resistance mechanisms in GBM. Herein, we report that concurrent treatment with the PARP inhibitor olaparib and XPO1 (exportin 1) inhibitor KPT330 showed synergetic anticancer effects on GBM cells. Mechanistically, in the nucleus, we show that KPT330 induced the nuclear retention of SQSTM1 (sequestosome 1) and further inhibited the ubiquitination of the DNA repair signal H2AX (H2A.X variant histone) mediated by olaparib, thus inhibiting DNA damage response and repair in GBM. Moreover, in the cytoplasm, KPT330 blocked the activation of autophagic flux caused by olaparib reagent, downregulated the expression of LAPTM4B (lysosomal protein transmembrane 4 beta) and induced the dysfunction of lysosomes, thereby preventing the degradation of autophagosome, and ultimately promoted cell death. Furthermore, in the LN229-luc mouse orthotopic xenograft model, combination treatment showed significantly increased antitumor efficacy compared to each monotherapy. These data illustrate the application prospects of combined oral administration of olaparib and KPT330 for the treatment of glioblastoma. AO: acridine orange; ATM: ATM serine/threonine kinase; CHEK1: checkpoint kinase 1; CHEK2: checkpoint kinase 2; CI: combination index; DMSO: dimethyl sulfoxide; DSBs: double-strand breaks; GBM: glioblastoma; HR: homologous recombination; H2AX: H2A.X variant histone; IHC: immunohistochemistry; LAPTM4B: lysosomal protein transmembrane 4 beta; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; PARP: poly(ADP-ribose) polymerase; RAD51: RAD51 recombinase; SQSTM1: sequestosome 1; SSBs: single-strand breaks; RNF168: ring finger protein 168; XPO1: exportin 1. [ABSTRACT FROM AUTHOR]

Introduction: Mutations of CHEK2 are usually inherited and have been implicated in breast cancers, colorectal cancers, thyroid cancers, kidney cancers, and prostate cancers. The CHEK2 gene codes for checkpoint kinase 2 protein which is an effector in the ATM-CHEK2-p53 pathway and responds to DNA double-strand breaks. Case Presentation: We describe a unique case of a 29-year-old Canadian female who presented with synchronous papillary thyroid carcinoma and rectal adenocarcinoma who was subsequently found to have a sporadic CHEK2 (checkpoint kinase 2) mutation. She presented with an 8-month history of bright red blood per rectum and saw two different physicians who diagnosed hemorrhoids and possible rectal ulcers, respectively. When the symptoms continued, the patient pursued a colonoscopy exam which found a large rectal tumor. Subsequent clinical staging diagnosed a rectal adenocarcinoma and a synchronous papillary thyroid carcinoma. Due to her synchronous tumors, a genetic panel was performed, which revealed a low-risk CHEK2 mutation. Our patient had a full response to neoadjuvant brachytherapy of the rectum and surgical treatment of her cancers. Conclusion: This is the first case report, to our knowledge, of a patient with a CHEK2 mutation who presented with synchronous papillary thyroid carcinoma and invasive colonic adenocarcinoma. The incidence of colorectal cancers and papillary thyroid cancers in those under 30 with no family history is very low, which signifies the rarity of their simultaneous occurrence at such a young age. [ABSTRACT FROM AUTHOR]

Background: In our previous study, we observed a synergistic effect of 2,3,5,4'-Tetrahydroxystilbene-2-O-b-D-glucoside combined with adriamycin to induce apoptosis in MCF-7 breast cancer cells. However, the underlying mechanisms of epigenetic modifications, such as alternative splicing, have not been explored. In this study, we aimed to investigate the mechanism by which THSG inhibits MCF-7 cell proliferation using full-length transcriptome sequencing. Methods: First, cell viability was examined using the methyl thiazolyl tetrazolium method and full-length transcriptome sequencing was performed to identify genes and pathways. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used to identify the principal pathways and targets of THSG. Flow cytometry analysis of cell cycle distribution was performed. Meanwhile, the analysis of alternative splicing and domains of the key proteins was conducted. Quantitative polymerase chain reaction and western blotting were performed for verification. Results: THSG showed significant cytotoxic activity in MCF-7 cells. Full-length transcriptome sequencing revealed differential alternative splicing with 173 upregulated and 263 downregulated genes. Further analysis identified distinct differential expression of genes (CHEK2-211 and CCND1-201) involved in the cell cycle in the THSG-treated group. Subsequently, alternative splicing types of CHEK2 (mutually exclusive exon) and CCND1 (intron retention). We found that THSG downregulated mRNA expression, as confirmed by quantitative polymerase chain reaction analysis. Interestingly, protein structural analysis revealed that THSG treatment led to the generation of CHK2-211, which was the result of a mutation in the amino acid residues (GLU-150, ASN-151) of the CHEK2 domain (VAL-150, GLY-151). and CyclinD1-201 were obtained when an amino acid (ASP-267) in the domain was lost in CyclinD1. Moreover, molecular docking analysis demonstrated that the domains of key proteins could bind THSG more effectively, with no difference in affinity. Western blotting confirmed that THSG inhibited the expression of CHK2 and CyclinD1. Conclusion: THSG modulated the alternative splicing of CHEK2 and CCND1 by inducing G0/G1 cell cycle arrest, consequently suppressing MCF-7 cell proliferation. [ABSTRACT FROM AUTHOR]

Background and Objectives: Germline DNA damage response (DDR) gene mutations correlate with increased prostate cancer (PCa) risk and a more aggressive form of the disease. DDR mutation testing is recommended for metastatic PCa cases, while eligible information about the mutations' burden in the early-stage localized PCa is still limited. This study is aimed at the prospective detection of DDR pathway mutations in cases with localized PCa and correlation with clinical, histopathological, and radiological data. A comparison to the previously assessed cohort of the advanced PCa was performed. Materials and Methods: Germline DDR gene mutations were assessed prospectively in DNA samples from 139 patients, using a five-gene panel (BRCA1, BRCA2, ATM, CHEK2, and NBN) targeted next-generation sequencing. Results: This study revealed an almost three-fold higher risk of localized PCa among mutation carriers as compared to non-carriers (OR 2.84 and 95% CI: 0.75–20.23, p = 0.16). The prevalence of germline DDR gene mutations in PCa cases was 16.8% (18/107) and they were detected only in cases with PI-RADS 4/5 lesions. BRCA1/BRCA2/ATM mutation carriers were 2.6 times more likely to have a higher (>1) cISUP grade group compared to those with a CHEK2 mutation (p = 0.27). However, the number of cISUP > 1-grade patients with a CHEK2 mutation was significantly higher in advanced PCa than in localized PCa: 66.67% vs. 23.08% (p = 0.047). Conclusions: The results of our study suggest the potential of genetic screening for selected DDR gene mutations for early identification of cases at risk of aggressive PCa. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is an increasing public health issue worldwide. BC incidence and mortality rates are rising in transitioning countries in Africa, with the most rapid increase occurring in Sub-Saharan Africa (SSA). Female BC represents 25.8% of all cancer diagnosis in SSA. Early age at onset, high grade and triple negative tumors are hallmarks of BC in this region, associated with germline pathogenic variants in susceptibility genes. While several genes have been associated with genetic predisposition (BRCA1, BRCA2, PALB2, TP53, PTEN, CDH1, STK11, ATM, CHEK2, NBN, BARD1, BRIP1, RAD50, RAD51C, RAD51D, … ), most studies have reported contribution of BRCA1 and BRCA2 pathogenic variants. Genetic contribution of BRCA genes has been estimated at 27% in Caucasian women. Available data from population of African origin are scarce and have mainly focused on pathogenic variants of BRCA1 and BRCA2. Reports from main studies on large sample size highlighted that BRCA1 still the major gene associated with BC in SSA. In addition, BRCA2, PALB2, and P53, are also on the top major genes with high penetrance, associated with BC. Mutation spectrum of BC genes in black African women seems to be different from Caucasian with increasing number of founder mutations identified. We hypothesis that the genetic contribution of known BC genes may be different between women of black African origin compared to Caucasians. In this review we explore the genetic contribution of known breast cancer genes in women of African origin, and discuss perspectives for prevention and patients care strategies in the era of precision medicine. [ABSTRACT FROM AUTHOR]

Individual genetic background can play an essential role in determining the development of esophageal squamous cell carcinoma (ESCC). PTPN13 and CHEK2 play important roles in the pathogenesis of ESCC. This case-control study aimed to analyze the association between gene polymorphisms and ESCC susceptibility. DNA was extracted from the peripheral blood of patients. The Agena MassARRAY platform was used for the genotyping. Statistical analysis was conducted using the chi-squared test or Fisher's exact test, logistic regression analysis, and stratification analysis. The 'G' allele of rs989902 (PTPN13) and the 'T' allele of rs738722 (CHEK2) were both associated with an increased risk of ESCC (rs989902: OR = 1.23, 95% CI = 1.02–1.47, p = 0.028; rs738722: OR = 1.28, 95% CI = 1.06–1.55, p = 0.011). Stratification analysis showed that SNPs (rs989902 and rs738722) were notably correlated with an increased risk of ESCC after stratification for age, sex, smoking, and drinking status. In addition, rs738722 might be associated with lower stage, while rs989902 had a lower risk of metastasis. Our findings display that PTPN13 rs989902 and CHEK2 rs738722 are associated with an increased risk of ESCC in the Chinese Han population. [ABSTRACT FROM AUTHOR]

Cyclic GMP–AMP synthase (cGAS), initially identified as a cytosolic DNA sensor, detects DNA fragments to trigger an innate immune response. Recently, accumulating evidence reveals the presence of cGAS within the nucleus. However, the biological functions of nuclear cGAS are not fully understood. Here, we demonstrate that nuclear cGAS represses LINE-1 (L1) retrotransposition to preserve genome integrity in human cells. Mechanistically, the E3 ligase TRIM41 interacts with and ubiquitinates ORF2p to influence its stability, and cGAS enhances the association of ORF2p with TRIM41, thereby promoting TRIM41-mediated ORF2p degradation and the suppression of L1 retrotransposition. In response to DNA damage, cGAS is phosphorylated at serine residues 120 and 305 by CHK2, which promotes cGAS-TRIM41 association, facilitating TRIM41-mediated ORF2p degradation. Moreover, we show that nuclear cGAS mediates the repression of L1 retrotransposition in senescent cells induced by DNA damage agents. We also identify several cancer-associated cGAS mutations that abolish the suppressive effect on L1 retrotransposition by disrupting the CHK2-cGAS-TRIM41-ORF2p regulatory axis. Together, these findings indicate that nuclear cGAS exhibits an inhibitory function in L1 retrotransposition which could provide avenues for future interventions in both aging and tumorigenesis. Zhen and colleagues show that nuclear cGAS represses L1 retrotransposition to stabilize the genome by enhancing the interaction between ORF2p and the E3 ligase TRIM41 upon DNA damage, which leads to the ubiquitination and degradation of ORF2p. [ABSTRACT FROM AUTHOR]