CHEK2 variants: linking functional impact to cancer risk

Rare Germline Variants in DNA Repair Genes Detected in BRCA-Negative Finnish Patients with Early-Onset Breast Cancer

BACKGROUND

Breast cancer is the most common malignancy, with a mean age of onset of approximately 60 years. Only a minority of breast cancer patients present with an early onset at or before 40 years of age. An exceptionally young age at diagnosis hints at a possible genetic etiology. Currently, known pathogenic genetic variants only partially explain the disease burden of younger patients. Thus, new knowledge is warranted regarding additional risk variants. In this study, we analyzed DNA repair genes to identify additional variants to shed light on the etiology of early-onset breast cancer.

METHODS

Germline whole-exome sequencing was conducted in a cohort of 63 patients diagnosed with breast cancer at or before 40 years of age (median 33, mean 33.02, range 23-40 years) with no known pathogenic variants in BRCA genes. After filtering, all detected rare variants were sorted by pathogenicity prediction scores (CADD score and REVEL) to identify the most damaging genetic changes. The remaining variants were then validated by comparison to a validation cohort of 121 breast cancer patients with no preselected age at cancer diagnosis (mean 51.4 years, range 28-80 years). Analysis of novel exonic variants was based on protein structure modeling.

RESULTS

Five novel, deleterious variants in the genes WRN, RNF8, TOP3A, ERCC2, and TREX2 were found in addition to a splice acceptor variant in RNF4 and two frameshift variants in EXO1 and POLE genes, respectively. There were also multiple previously reported putative risk variants in other DNA repair genes.

CONCLUSIONS

Taken together, whole-exome sequencing yielded 72 deleterious variants, including 8 novel variants that may play a pivotal role in the development of early-onset breast cancer. Although more studies are warranted, we demonstrate that young breast cancer patients tend to carry multiple deleterious variants in one or more DNA repair genes.

Germline variant profiling of CHEK2 sequencing variants in breast cancer patients

The cell cycle checkpoint kinase 2 (CHEK2) is a tumor suppressor gene coding for a protein kinase with a role in the cell cycle and DNA repair pathways. Variants within CHEK2 are associated with an increased risk of developing breast, colorectal, prostate and several other types of cancer. Comprehensive genetic risk assessment leads to early detection of hereditary cancer and provides an opportunity for better survival. Multigene panel screening can identify the presence of pathogenic variants in hereditary cancer predisposition genes (HCPG), including CHEK2. Multigene panels, however, also result in large quantities of genetic data some of which cannot be interpreted and are classified as variants of uncertain significance (VUS). A VUS provides no information for use in medical management and leads to ambiguity in genetic counseling. In the absence of variant segregation data, in vitro functional analyses can be used to clarify variant annotations, aiding in accurate clinical management of patient risk and treatment plans. In this study, we performed whole exome sequencing (WES) to investigate the prevalence of germline variants in 210 breast cancer (BC) patients and conspicuously among the many variants in HCPGs that we found, we identified 16 individuals with non-synonymous or frameshift CHEK2 variants, sometimes along with additional variants within other BC susceptibility genes. Using this data, we investigated the prevalence of these CHEK2 variants in African American (AA) and Caucasian (CA) populations identifying the presence of two novel frameshift variants, c.1350delA (p.Val451Serfs*18) and c.1528delC (p.Gln510Argfs*3) and a novel missense variant, c262C>T (p.Pro88Ser). Along with the current clinical classifications, we assembled available experimental data and computational predictions of function for these CHEK2 variants, as well as explored the role these variants may play in polygenic risk assessment.

Comprehensive analysis of the functional impact of single nucleotide variants of human CHEK2

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.

Discovery of a Highly Potent and Selective BRD9 PROTAC Degrader Based on E3 Binder Investigation for the Treatment of Hematological Tumors

BRD9 is a pivotal epigenetic factor involved in cancers and inflammatory diseases. Still, the limited selectivity and poor phenotypic activity of targeted agents make it an atypically undruggable target. PROTAC offers an alternative strategy for overcoming the issue. In this study, we explored diverse E3 ligase ligands for the contribution of BRD9 PROTAC degradation. Through molecular docking, binding affinity analysis, and structure-activity relationship study, we identified a highly potent PROTAC E5, with excellent BRD9 degradation (DC50 = 16 pM) and antiproliferation in MV4-11 cells (IC50 = 0.27 nM) and OCI-LY10 cells (IC50 = 1.04 nM). E5 can selectively degrade BRD9 and induce cell cycle arrest and apoptosis. Moreover, the therapeutic efficacy of E5 was confirmed in xenograft tumor models, accompanied by further RNA-seq analysis. Therefore, these results may pave the way and provide the reference for the discovery and investigation of highly effective PROTAC degraders.

Germline rare variants in HER2-positive breast cancer predisposition: a systematic review and meta-analysis

Introduction

Approximately 10% of breast cancer (BC) cases result from hereditary causes. Genetic testing has been widely implemented in BC care to determine hereditary cancer syndromes and personalized medicine. Thus, identification of individuals carrying germline pathogenic variants could be useful to provide appropriate prophylactic or screening measures for each BC subtype, however, there are few formal recommendations for genetic testing in this sense so far. In this study, we assessed rare germline variants in a specific group of genes in order to determine the association with human epidermal growth factor 2 enriched (HER2+) BC phenotype through a systematic review and meta-analysis comparing subtypes overexpressing HER2 with other clinically recognized subtypes of BC. This review was registered with PROSPERO (ID: CRD42023447571).

Methods

We conducted an online literature search in PubMed (MEDLINE), Scopus, and EMBASE databases. We included original studies that investigated germline variants in HER2+ BC patients and selected the studies that reported only rare and/or pathogenic germline variants. We assessed the risk of bias and quality of the studies using the Joanna Briggs Institute Critical Appraisal checklists and the Modified Newcastle-Ottawa Scale for Genetic Studies, respectively. Considering hormone receptor and HER2 expression status, we compared gene-based risks initially in HR-HER2-, HR+HER2-, HR+HER2+, and HR-HER2+ groups, conducting separate meta-analyses using the random effects model for each comparison, and within them for each gene.

Results

Of the total 36 studies describing germline variants, 11 studies provided information on the prevalence of variants in the different clinically relevant BC subtypes and allowed comparisons. Germline variants within eight genes showed significant differences when meta-analyzed between the BC groups: BRCA1, BRCA2, TP53, ATM, CHEK2, PALB2, RAD51C, and BARD1. Notably, TP53, ATM, and CHEK2 germline variants were identified as predisposing factors for HER2+ subtypes, whereas BRCA1, BRCA2, PALB2, RAD51C, and BARD1 germline variants were associated with a predisposition to low HER2 expression. Main concerns about bias and quality assessment were the lack of confounding factors control; and comparability or outcome assessment, respectively.

Discussion

Our findings underscore the connection between germline variants and differential expression of the HER2 protein and BC subtypes.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023447571.

Multilocus inherited neoplasia allele syndrome: report of uncommon combinations between CHEK2/ATM and BRCA1/CDKN2A genes

Background

Multilocus inherited neoplasia allelic syndrome (MINAS) is a recently coined term that describes the coexistence of two or more pathogenic variants (PVs) in cancer susceptibility genes (CSGs) in a single individual.

Case presentation

This article presents two cases of MINAS due to rare CSG combinations. The first was a 37-year-old woman carrying PVs in the mutated ataxia telangiectasia (ATM) and CHEK2 genes, with HER-2 positive unilateral breast cancer at 29. The second was a 53-year-old woman carrying PVs in the BRCA1 and CDKN2A genes, who presented with triple-negative breast cancer at 51. We describe their family history and treatment, where the lack of evidence for personalised management becomes evident.

Conclusion

Predicting the phenotypic effect of harbouring two variants in CSG is challenging. It is essential to encourage the notification of other cases and carry out functional studies to establish specific risks for affected individuals to develop personalised follow-up guidelines to reduce the associated morbimortality.

Clinico-genomic findings, molecular docking, and mutational spectrum in an understudied population with breast cancer patients from KP, Pakistan

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.

Lactate in breast cancer cells is associated with evasion of hypoxia-induced cell cycle arrest and adverse patient outcome

Tumor hypoxia is a common microenvironmental factor in breast cancers, resulting in stabilization of Hypoxia-Inducible Factor 1 (HIF-1), the master regulator of hypoxic response in cells. Metabolic adaptation by HIF-1 results in inhibition of citric acid cycle, causing accumulation of lactate in large concentrations in hypoxic cancers. Lactate can therefore serve as a secondary microenvironmental factor influencing cellular response to hypoxia. Presence of lactate can alter the hypoxic response of breast cancers in many ways, sometimes in opposite manners. Lactate stabilizes HIF-1 in oxidative condition, as well as destabilizes HIF-1 in hypoxia, increases cellular acidification, and mitigates HIF-1-driven inhibition of cellular respiration. We therefore tested the effect of lactate in MDA-MB-231 under hypoxia, finding that lactate can activate pathways associated with DNA replication, and cell cycling, as well as tissue morphogenesis associated with invasive processes. Using a bioengineered nano-patterned stromal invasion assay, we also confirmed that high lactate and induced HIF-1α gene overexpression can synergistically promote MDA-MB-231 dissemination and stromal trespass. Furthermore, using The Cancer Genome Atlas, we also surprisingly found that lactate in hypoxia promotes gene expression signatures prognosticating low survival in breast cancer patients. Our work documents that lactate accumulation contributes to increased heterogeneity in breast cancer gene expression promoting cancer growth and reducing patient survival.

Comprehensive splicing analysis of the alternatively spliced CHEK2 exons 8 and 10 reveals three enhancer/silencer-rich regions and 38 spliceogenic variants

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.

Germline genetic variants in Turkish familial multiple myeloma/monoclonal gammopathy of undetermined significance cases

Multiple myeloma (MM) is a haematological malignancy primarily affecting the elderly, with a striking male predilection and ethnic disparities in incidence. Familial predisposition to MM has long been recognized, but the genetic underpinnings remain elusive. This study aimed to investigate germline variants in Turkish families with recurrent MM cases. A total of 37 MM-affected families, comprising 77 individuals, were included. Targeted next-generation sequencing analysis yielded no previously reported rare variants. Whole exome sequencing analysis in 11 families identified rare disease-causing variants in various genes, some previously linked to familial MM and others not previously associated. Notably, genes involved in ubiquitination, V(D)J recombination and the PI3K/AKT/mTOR pathway were among those identified. Furthermore, a specific variant in BNIP1 (rs28199) was found in 13 patients across nine families, indicating its potential significance in MM pathogenesis. While this study sheds light on genetic variations in familial MM in Turkey, its limitations include sample size and the absence of in vivo investigations. In conclusion, familial MM likely involves a polygenic inheritance pattern with rare, disease-causing variants in various genes, emphasizing the need for international collaborative efforts to unravel the intricate genetic basis of MM and develop targeted therapies.

Machine learning reveals diverse cell death patterns in lung adenocarcinoma prognosis and therapy

Cancer cell growth, metastasis, and drug resistance pose significant challenges in the management of lung adenocarcinoma (LUAD). However, there is a deficiency in optimal predictive models capable of accurately forecasting patient prognoses and guiding the selection of targeted treatments. Programmed cell death (PCD) pathways play a pivotal role in the development and progression of various cancers, offering potential as prognostic indicators and drug sensitivity markers for LUAD patients. The development and validation of predictive models were conducted by integrating 13 PCD patterns with comprehensive analysis of bulk RNA, single-cell RNA transcriptomics, and pertinent clinicopathological details derived from TCGA-LUAD and six GEO datasets. Utilizing the machine learning algorithms, we identified ten critical differentially expressed genes associated with PCD in LUAD, namely CHEK2, KRT18, RRM2, GAPDH, MMP1, CHRNA5, TMPRSS4, ITGB4, CD79A, and CTLA4. Subsequently, we conducted a programmed cell death index (PCDI) based on these genes across the aforementioned cohorts and integrated this index with relevant clinical features to develop several prognostic nomograms. Furthermore, we observed a significant correlation between the PCDI and immune features in LUAD, including immune cell infiltration and the expression of immune checkpoint molecules. Additionally, we found that patients with a high PCDI score may exhibit resistance to immunotherapy and standard adjuvant chemotherapy regimens; however, they may benefit from other FDA-supported drugs such as docetaxel and dasatinib. In conclusion, the PCDI holds potential as a prognostic signature and can facilitate personalized treatment for LUAD patients.

Genetic Basis of Breast and Ovarian Cancer: Approaches and Lessons Learnt from Three Decades of Inherited Predisposition Testing

Germline variants occurring in BRCA1 and BRCA2 give rise to hereditary breast and ovarian cancer (HBOC) syndrome, predisposing to breast, ovarian, fallopian tube, and peritoneal cancers marked by elevated incidences of genomic aberrations that correspond to poor prognoses. These genes are in fact involved in genetic integrity, particularly in the process of homologous recombination (HR) DNA repair, a high-fidelity repair system for mending DNA double-strand breaks. In addition to its implication in HBOC pathogenesis, the impairment of HR has become a prime target for therapeutic intervention utilizing poly (ADP-ribose) polymerase (PARP) inhibitors. In the present review, we introduce the molecular roles of HR orchestrated by BRCA1 and BRCA2 within the framework of sensitivity to PARP inhibitors. We examine the genetic architecture underneath breast and ovarian cancer ranging from high- and mid- to low-penetrant predisposing genes and taking into account both germline and somatic variations. Finally, we consider higher levels of complexity of the genomic landscape such as polygenic risk scores and other approaches aiming to optimize therapeutic and preventive strategies for breast and ovarian cancer.

CHEK2 knockout is a therapeutic target for TP53-mutated hepatocellular carcinoma

Currently, there is still a lack of novel and effective drug targets to improve the prognosis of hepatocellular carcinoma (HCC). Additionally, the role of CHEK2 in HCC has not been reported yet. The eQTLgen database and two HCC Genome-Wide Association Study (GWAS) datasets (ieu-b-4953, ICD10 C22.0) were used to find the drug target: CHEK2. Next, Colony, Edu, β-gal, and cell cycle analysis were facilitated to evaluate the role of CHEK2 knockout in HCC. In addition, Nultin-3 was added to evaluate the apoptosis of TP53-mutated HCC cells with CHEK2 knockout. Furthermore, MitoSox, electron microscopy, mitochondrial ATP, and NADH+/NADH levels were assessed in the CHEK2 knockout HCC cells with or without Metformin. Finally, cell-derived tumor xenograft was used to evaluate the role of CHEK2 knockout in vivo. We initially identified a potential drug target, CHEK2, through GWAS data analysis. Furthermore, we observed a significant upregulation of CHEK2 expression in HCC, which was found to be correlated with a poor prognosis. Subsequently, the results indicated that knocking out CHEK2 selectively affects the proliferation, cell cycle, senescence, and apoptosis of TP53-mutant HCC cells. Additionally, the introduction of Nultin-3 further intensified the functional impact on TP53-mutant cells. Then ClusterProfiler results showed high CHEK2 and TP53 mutation group was positively enriched in the mitochondrial ATP pathway. Then we used MitoSox, electron microscopy, mitochondrial ATP, and NADH + /NADH assay and found knockout of CHECK could induce the ATP pathway to inhibit the growth of HCC. Our research introduces a novel drug target for TP53-mutant HCC cells via mitochondrial ATP, addressing the limitation of Nultin-3 as a standalone treatment that does not induce tumor cell death.

Systematic Minigene-Based Splicing Analysis and Tentative Clinical Classification of 52 CHEK2 Splice-Site Variants

BACKGROUND

Disrupted pre-mRNA splicing is a frequent deleterious mechanism in hereditary cancer. We aimed to functionally analyze candidate spliceogenic variants of the breast cancer susceptibility gene CHEK2 by splicing reporter minigenes.

METHODS

A total of 128 CHEK2 splice-site variants identified in the Breast Cancer After Diagnostic Gene Sequencing (BRIDGES) project (https://cordis.europa.eu/project/id/634935) were analyzed with MaxEntScan and subsetted to 52 variants predicted to impact splicing. Three CHEK2 minigenes, which span all 15 exons, were constructed and validated. The 52 selected variants were then genetically engineered into the minigenes and assayed in MCF-7 (human breast adenocarcinoma) cells.

RESULTS

Of 52 variants, 46 (88.5%) impaired splicing. Some of them led to complex splicing patterns with up to 11 different transcripts. Thirty-four variants induced splicing anomalies without any trace or negligible amounts of the full-length transcript. A total of 89 different transcripts were annotated, which derived from different events: single- or multi-exon skipping, alternative site-usage, mutually exclusive exon inclusion, intron retention or combinations of the abovementioned events. Fifty-nine transcripts were predicted to introduce premature termination codons, 7 kept the original open-reading frame, 5 removed the translation start codon, 6 affected the 5'UTR (Untranslated Region), and 2 included missense variations. Analysis of variant c.684-2A > G revealed the activation of a non-canonical TG-acceptor site and exon 6 sequences critical for its recognition.

CONCLUSIONS

Incorporation of minigene read-outs into an ACMG/AMP (American College of Medical Genetics and Genomics/Association for Molecular Pathology)-based classification scheme allowed us to classify 32 CHEK2 variants (27 pathogenic/likely pathogenic and 5 likely benign). However, 20 variants (38%) remained of uncertain significance, reflecting in part the complex splicing patterns of this gene.

CHEK2 is a potential prognostic biomarker associated with immune infiltration in clear cell renal cell carcinoma

Checkpoint kinase 2 (CHEK2) plays a crucial role in responding to DNA damage and is linked to diverse cancer types. However, its significance in the prediction of prognosis and impacts on the immune status of clear cell renal cell carcinoma (ccRCC) remains unclear. This study aimed to identify the role of CHEK2 in prognosis and immune microenvironment of ccRCC. We analyzed transcriptome and clinicopathological data from the cancer genome atlas (TCGA) database and conducted functional enrichment analysis to explore molecular mechanisms. The relationship between CHEK2 and immune infiltration was evaluated, and drug sensitivity analysis was performed using the CellMiner database. The results showed that CHEK2 was an independent predictor of ccRCC prognosis and was closely associated with immune-related processes. Additionally, high expression of CHEK2 was linked to resistance to certain targeted drugs. These findings suggest that CHEK2 could serve as a biomarker for ccRCC, providing insights into tumor immune microenvironment alterations and immunotherapeutic response. Further investigation is needed to fully understand the potential of CHEK2 as a prognostic predictor and therapeutic target for ccRCC.

ENIGMA CHEK2gether Project: A Comprehensive Study Identifies Functionally Impaired CHEK2 Germline Missense Variants Associated with Increased Breast Cancer Risk

PURPOSE

Germline pathogenic variants in CHEK2 confer moderately elevated breast cancer risk (odds ratio, OR ∼ 2.5), qualifying carriers for enhanced breast cancer screening. Besides pathogenic variants, dozens of missense CHEK2 variants of uncertain significance (VUS) have been identified, hampering the clinical utility of germline genetic testing (GGT).

EXPERIMENTAL DESIGN

We collected 460 CHEK2 missense VUS identified by the ENIGMA consortium in 15 countries. Their functional characterization was performed using CHEK2-complementation assays quantifying KAP1 phosphorylation and CHK2 autophosphorylation in human RPE1-CHEK2-knockout cells. Concordant results in both functional assays were used to categorize CHEK2 VUS from 12 ENIGMA case-control datasets, including 73,048 female patients with breast cancer and 88,658 ethnicity-matched controls.

RESULTS

A total of 430/460 VUS were successfully analyzed, of which 340 (79.1%) were concordant in both functional assays and categorized as functionally impaired (N = 102), functionally intermediate (N = 12), or functionally wild-type (WT)-like (N = 226). We then examined their association with breast cancer risk in the case-control analysis. The OR and 95% CI (confidence intervals) for carriers of functionally impaired, intermediate, and WT-like variants were 2.83 (95% CI, 2.35-3.41), 1.57 (95% CI, 1.41-1.75), and 1.19 (95% CI, 1.08-1.31), respectively. The meta-analysis of population-specific datasets showed similar results.

CONCLUSIONS

We determined the functional consequences for the majority of CHEK2 missense VUS found in patients with breast cancer (3,660/4,436; 82.5%). Carriers of functionally impaired missense variants accounted for 0.5% of patients with breast cancer and were associated with a moderate risk similar to that of truncating CHEK2 variants. In contrast, 2.2% of all patients with breast cancer carried functionally wild-type/intermediate missense variants with no clinically relevant breast cancer risk in heterozygous carriers.

CHEK2 Alterations in Pediatric Malignancy: A Single-Institution Experience

Background: Approximately 10% of pediatric malignancies are secondary to germline alterations in cancer-predisposing genes. Checkpoint kinase 2 (CHEK2) germline loss-of-function variants have been reported in pediatric cancer patients, but clinical phenotypes and outcomes are poorly described. We present our single-institution experience of pediatric oncology patients with CHEK2 germline alterations, including clinical presentations and outcomes. Methods: Pediatric oncology patients with CHEK2 germline alterations were identified among those assessed by clinical or translational research at the Institute for Genomic Medicine at Nationwide Children’s Hospital. A chart review of disease course was conducted on identified patients. Results: We identified 6 patients with germline CHEK2 variants from a cohort of 300 individuals, including 1 patient with concurrent presentation of Burkitt lymphoma and neuroblastoma, 3 patients with brain tumors, 1 patient with Ewing sarcoma, and 1 patient with myelodysplastic syndrome. Three patients had a family history of malignancies. Four patients were in remission; one was undergoing treatment; one patient had developed treatment-related meningiomas. We review prior data regarding CHEK2 variants in this population, challenges associated with variant interpretation, and genetic counseling for individuals with CHEK2 variants. Conclusions: CHEK2 germline loss-of-function alterations occur in patients with a variety of pediatric tumors. Larger multicenter studies will improve our understanding of the incidence, phenotype, and molecular biology of CHEK2 germline variants in pediatric cancers.

A novel anoikis-related prognostic signature associated with prognosis and immune infiltration landscape in clear cell renal cell carcinoma

Background: Clear cell renal cell carcinoma (ccRCC) is the most common histological subtype of renal cell carcinoma (RCC). Anoikis plays an essential function in tumourigenesis, whereas the role of anoikis in ccRCC remains unclear. Methods: Anoikis-related genes (ARGs) were collected from the MSigDB database. According to univariate Cox regression analysis, the least absolute shrinkage and selection operator (LASSO) algorithm was utilized to select the ARGs associated with the overall rate (OS). Multivariate Cox regression analysis was conducted to identify 5 prognostic ARGs, and a risk model was established. The Kaplan-Meier survival analysis was used to evaluate the OS rate of ccRCC patients. Gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and Gene set enrichment analysis (GSVA) were utilized to investigate the molecular mechanism of patients in the low- and high-risk group. ESTIMATE, CIBERSOT, and single sample gene set enrichment analysis (ssGSEA) algorithms were conducted to estimate the immune infiltration landscape. Consensus clustering analysis was performed to divide the patients into different subgroups. Results: A fresh risk model was constructed based on the 5 prognostic ARGs (CHEK2, PDK4, ZNF304, SNAI2, SRC). The Kaplan-Meier survival analysis indicated that the OS rate of patients with a low-risk score was significantly higher than those with a high-risk score. Consensus clustering analysis successfully clustered the patients into two subgroups, with a remarkable difference in immune infiltration landscape and prognosis. The ESTIMATE, CIBERSORT, and ssGSEA results illustrated a significant gap in immune infiltration landscape of patients in the low- and high-risk group. Enrichment analysis and GSVA revealed that immune-related signaling pathways might mediate the role of ARGs in ccRCC. The nomogram results illustrated that the ARGs prognostic signature was an independent prognostic predictor that distinguished it from other clinical characteristics. TIDE score showed a promising immunotherapy response of ccRCC patients in different risk subgroups and cluster subgroups. Conclusion: Our study revealed that ARGs play a carcinogenic role in ccRCC. Additionally, we firstly integrated multiple ARGs to establish a risk-predictive model. This study highlights that ARGs could be implemented as a stratification factor for individualized and precise treatment in ccRCC patients.

Application of Multigene Panels Testing for Hereditary Cancer Syndromes

BACKGROUND

Approximately 5-10% of all cancers are associated with hereditary cancer predisposition syndromes (HCPS). Early identification of HCPS is facilitated by widespread use of next-generation sequencing (NGS) and brings significant benefits to both the patient and their relatives. This study aims to evaluate the landscape of genetic variants in patients with personal and/or family history of cancer using NGS-based multigene panel testing.

MATERIALS AND METHODS

The study cohort included 1117 probands from Russia: 1060 (94.9%) patients with clinical signs of HCPS and 57 (5.1%) healthy individuals with family history of cancer. NGS analysis of 76 HCPS genes was performed using a custom Roche NimbleGen enrichment panel.

RESULTS

Pathogenic/likely pathogenic variants were identified in 378 of 1117 individuals (33.8%). The predominant number (59.8%) of genetic variants was identified in BRCA1/BRCA2 genes. CHEK2 was the second most commonly altered gene with a total of 28 (7.4%) variants, and 124 (32.8%) genetic variants were found in other 35 cancer-associated genes with variable penetrance.

CONCLUSIONS

Multigene panel testing allows for a differential diagnosis and identification of high-risk group for oncological diseases. Our results demonstrate that inclusion of non-coding gene regions into HCPS gene panels is highly important for the identification of rare spliceogenic variants with high penetrance.