Cancer Driver Mutations Research Articles

Oncogenic driver mutations in non-small cell lung cancer: Past, present and future.

Lung cancer, of which non-small lung cancer is the most common subtype, represents the leading cause of cancer related-death worldwide. It is now recognized that a significant proportion of these patients present alterations in certain genes that drive oncogenesis. In recent years, more of these so-called oncogenic drivers have been identified, and a better understanding of their biology has allowed the development new targeted agents. This review aims to provide an update about the current landscape of driver mutation in non-small-cell lung cancer. Alterations in Kirsten rat sarcoma, epidermal growth factor receptor, MET, anaplastic lymphoma kinase, c-ROS oncogene 1, v-raf murine sarcoma viral oncogene homolog B, neurotrophic receptor tyrosine kinase, human epidermal growth factor 2, neuregulin-1 and rearranged during transfection are discussed, as well as agents targeting these alterations. Current standards of treatment as well as promising future strategies are presented. Currently, more than fifteen targeted agents are food and Drug administration-approved for seven oncogenic drivers in non-small-cell lung cancer, highlighting the importance of actively searching for these mutations. Continuous and future efforts made in defining the biology of each of these alterations will help to elucidate their respective resistance mechanisms, and to define the best treatment strategy and therapeutic sequence.

EPHA2-dependent outcompetition of KRASG12D mutant cells by wild-type neighbors in the adult pancreas

SummaryAs we age, our tissues are repeatedly challenged by mutational insult, yet cancer occurrence is a relatively rare event. Cells carrying cancer-causing genetic mutations compete with normal neighbors for space and survival in tissues. However, the mechanisms underlying mutant-normal competition in adult tissues and the relevance of this process to cancer remain incompletely understood. Here, we investigate how the adult pancreas maintains tissue health in vivo following sporadic expression of oncogenic Kras (KrasG12D), the key driver mutation in human pancreatic cancer. We find that when present in tissues in low numbers, KrasG12D mutant cells are outcompeted and cleared from exocrine and endocrine compartments in vivo. Using quantitative 3D tissue imaging, we show that before being cleared, KrasG12D cells lose cell volume, pack into round clusters, and E-cadherin-based cell-cell adhesions decrease at boundaries with normal neighbors. We identify EphA2 receptor as an essential signal in the clearance of KrasG12D cells from exocrine and endocrine tissues in vivo. In the absence of functional EphA2, KrasG12D cells do not alter cell volume or shape, E-cadherin-based cell-cell adhesions increase and KrasG12D cells are retained in tissues. The retention of KRasG12D cells leads to the early appearance of premalignant pancreatic intraepithelial neoplasia (PanINs) in tissues. Our data show that adult pancreas tissues remodel to clear KrasG12D cells and maintain tissue health. This study provides evidence to support a conserved functional role of EphA2 in Ras-driven cell competition in epithelial tissues and suggests that EphA2 is a novel tumor suppressor in pancreatic cancer.

NTRK Fusion Genes in Thyroid Carcinomas: Clinicopathological Characteristics and Their Impacts on Prognosis.

Simple SummaryNTRK fusion genes are important but not well studied molecular markers in thyroid cancer. Their identification could help improve diagnosis and prognosis, and determine appropriate treatment. The aims of this study were to identify NTRK fusion-positive thyroid tumors in a large cohort of different thyroid tumors, to characterize these tumors by molecular, clinical and pathological features and to evaluate the impact of NTRK-rearranged tumors on prognosis of the disease. A suitable approach for selective NTRK fusion gene testing in thyroid cancer samples was created and utilized. In a cohort of 59 NTRK-rearranged carcinomas, characteristic features were described and recommendations for surgery and prognostic factors were determined thanks to the long-term follow-up of patients.Chromosomal rearrangements of NTRK genes are oncogenic driver mutations in thyroid cancer (TC). This study aimed to identify NTRK fusion-positive thyroid tumors and to correlate them with clinical and pathological data and determine their prognostic significance. The cohort consisted of 989 different TC samples. Based on the detected mutation, samples were triaged, and those that were positive for a BRAF, HRAS, KRAS, NRAS, RET, RET/PTC or PAX8/PPARγ mutation were excluded from further analyses. NTRK fusion gene testing was performed in 259 cases, including 126 cases using next-generation sequencing. NTRK fusion genes were detected in 57 of 846 (6.7%) papillary thyroid carcinomas and in 2 of 10 (20.0%) poorly differentiated thyroid carcinomas. A total of eight types of NTRK fusions were found, including ETV6/NTRK3, EML4/NTRK3, RBPMS/NTRK3, SQSTM1/NTRK3, TPM3/NTRK1, IRF2BP2/NTRK1, SQSTM1/NTRK1 and TPR/NTRK1. NTRK fusion-positive carcinomas were associated with the follicular growth pattern, chronic lymphocytic thyroiditis and lymph node metastases. NTRK1-rearranged carcinomas showed a higher frequency of multifocality and aggressivity than NTRK3-rearranged carcinomas. Tumor size, presence of metastases, positivity for the NTRK3 or NTRK1 fusion gene and a late mutation event (TERT or TP53 mutation) were determined as factors affecting patient prognosis. NTRK fusion genes are valuable diagnostic and prognostic markers.

Whole exome sequencing and deep sequencing of esophageal squamous cell carcinoma and adenocarcinoma in Japanese patients using the Japanese version of the Genome Atlas, JCGA

BackgroundRecent comprehensive mutation analyses have revealed a relatively small number of driver mutations in esophageal cancer, implicating a limited number of molecular targets, most of which are also implicated in squamous cell carcinoma.MethodsIn this study, we investigated genetic alterations in 44 esophageal squamous cell carcinomas (ESCC) and 8 adenocarcinomas (EAC) from Japanese patients as potential molecular targets, based on data from the Japanese version of The Genome Atlas (JCGA).ResultsEsophageal cancer was characterized by TP53 somatic mutations in ESCC (39/44, 88.6%) and EAC (5/8, 62.5%). In addition to TP53 mutations, somatic mutations in NFE2L2 (16/44, 36.4%), CDKN2A (7/44, 15.9%), and KMT2D (7/44, 15.9%) were more frequently detected in ESCC than in EAC. WRN-truncated type mutations that lead to genomic instability correlate with EAC, but not ESCC. ESCC samples were enriched in ALDH2-associated mutational signature 16 as well as the APOBEC signature. Patients with FAT2 mutations had significantly poorer overall survival compared with those with wild-type status at FAT2 (p < 0.05). Patients with EP300 or PTPRD mutations also had poor progression-free survival compared with respective wild-types (p < 0.05 or p < 0.001).ConclusionsThese findings may facilitate future precision medicine approaches based on genomic profiling in ESCC and EAC.

CarcSeq Measurement of Rat Mammary Cancer Driver Mutations and Relation to Spontaneous Mammary Neoplasia.

The ability to deduce carcinogenic potential from subchronic, repeat dose rodent studies would constitute a major advance in chemical safety assessment and drug development. This study investigated an error-corrected NGS method (CarcSeq) for quantifying cancer driver mutations (CDMs) and deriving a metric of clonal expansion predictive of future neoplastic potential. CarcSeq was designed to interrogate subsets of amplicons encompassing hotspot CDMs applicable to a variety of cancers. Previously, normal human breast DNA was analyzed by CarcSeq and metrics based on mammary-specific CDMs were correlated with tissue donor age, a surrogate of breast cancer risk. Here we report development of parallel methodologies for rat. The utility of the rat CarcSeq method for predicting neoplastic potential was investigated by analyzing mammary tissue of 16-week-old untreated rats with known differences in spontaneous mammary neoplasia (Fischer 344, Wistar Han, and Sprague Dawley). Hundreds of mutants with mutant fractions ≥ 10-4 were quantified in each strain, most were recurrent mutations, and 42.5% of the nonsynonymous mutations have human homologs. Mutants in the mammary-specific target of the most tumor-sensitive strain (Sprague Dawley) showed the greatest nonsynonymous/synonymous mutation ratio, indicative of positive selection consistent with clonal expansion. For the mammary-specific target (Hras, Pik3ca, and Tp53 amplicons), median absolute deviation correlated with percentages of rats that develop spontaneous mammary neoplasia at 104 weeks (Pearson r = 1.0000, 1-tailed p = .0010). Therefore, this study produced evidence CarcSeq analysis of spontaneously occurring CDMs can be used to derive an early metric of clonal expansion relatable to long-term neoplastic outcome.

CRISPR Screens in Synthetic Lethality and Combinatorial Therapies for Cancer.

Simple SummaryThe synthetic lethality (SL) clinical success of PARP inhibitors in homologous recombinant deficient tumors has established a new concept for cancer treatment. For decades, efforts have centered on identifying genetic interactions for determining essential tumoral genes, and more recently, SL interactions to determine combinational treatments against persistent cancer reappearance. Currently, the feasibility of CRISPR screen methodology has emerged as the state of the art for uncovering new SL or viable interactors in the biology and treatment of cancers. We present the up-to-date research of numerous laboratories that take advantage of the genome-wide forward genetic CRISPR screen tools and protocols to identify cancer biomarkers, genetic interactions and novel therapies. Indeed, investigations are nowadays focused on defining innovative combinatorial treatments based on SL interactions. By coupling different drugs, concentration treatments can be lowered and therefore toxicity reduced. CRISPR screen technologies have deeply impacted cancer research to promote a robust advance in combined therapies.Cancer is a complex disease resulting from the accumulation of genetic dysfunctions. Tumor heterogeneity causes the molecular variety that divergently controls responses to chemotherapy, leading to the recurrent problem of cancer reappearance. For many decades, efforts have focused on identifying essential tumoral genes and cancer driver mutations. More recently, prompted by the clinical success of the synthetic lethality (SL)-based therapy of the PARP inhibitors in homologous recombinant deficient tumors, scientists have centered their novel research on SL interactions (SLI). The state of the art to find new genetic interactions are currently large-scale forward genetic CRISPR screens. CRISPR technology has rapidly evolved to be a common tool in the vast majority of laboratories, as tools to implement CRISPR screen protocols are available to all researchers. Taking advantage of SLI, combinatorial therapies have become the ultimate model to treat cancer with lower toxicity, and therefore better efficiency. This review explores the CRISPR screen methodology, integrates the up-to-date published findings on CRISPR screens in the cancer field and proposes future directions to uncover cancer regulation and individual responses to chemotherapy.

Roles of phenotypic heterogeneity and microenvironment feedback in early tumor development.

The local microenvironment of a tumor plays an important and commonly observed role in cancer development and progression. Dynamic changes in the tissue microenvironment are thought to epigenetically disrupt healthy cellular phenotypes and drive cancer incidence. Despite the experimental work in this area there are no conceptual models to understand the interplay between the epigenetic dysregulation in the microenvironment of early tumors and the appearance of cancer driver mutations. Here, we develop a minimal model of the tissue microenvironment which considers three interacting subpopulations: healthy, phenotypically dysregulated, and mutated cancer cells. Healthy cells can epigenetically (reversibly) transition to the dysregulated phenotype, and from there to the cancer state. The epigenetic transition rates of noncancer cells can be influenced by the number of cancer cells in the microenvironment (termed microenvironment feedback). Our model delineates the regime in which microenvironment feedback accelerates the rate of cancer initiation. In addition, the model shows when and how microenvironment feedback may inhibit cancer progression. We discuss how our framework may provide resolution to some of the puzzling experimental observations of slow cancer progression.

Pancreatic cancer driver mutations are targetable through distant alternative RNA splicing dependencies.

Pancreatic ductal adenocarcinoma (PDAC), the most common histological subtype of pancreatic cancer, has one of the highest case fatality rates of all known solid malignancies. Over the past decade, several landmark studies have established mutations in KRAS and TP53 as the predominant drivers of PDAC pathogenesis and therapeutic resistance, though treatment options for PDACs and other tumors with these mutations remain extremely limited. Hampered by late tumor discovery and diagnosis, clinicians are often faced with using aggressive and non-specific chemotherapies to treat advanced disease. Clinically meaningful responses to targeted therapy are often limited to the minority of patients with susceptible PDACs, and immunotherapies have routinely encountered roadblocks in effective activation of tumor-infiltrating immune cells. Alternative RNA splicing (ARS) has recently gained traction in the PDAC literature as a field from which we may better understand and treat complex mechanisms of PDAC initiation, progression, and therapeutic resistance. Here, we review PDAC pathogenesis as it relates to fundamental ARS biology, with an extension to implications for PDAC patient clinical management.

Moving beyond epidermal growth factor receptor resistance in metastatic non-small cell lung cancer - a drug development perspective.

Epidermal Growth Factor Receptor (EGFR) mutations are the most common targetable oncogenic driver mutation in metastatic non-small lung cancer (NSCLC). There have been significant advances in the management of metastatic EGFR-mutant NSCLC from the advent of first and second generation EGFR inhibitors to, more recently, the third-generation inhibitor osimertinib. Osimeritinib is now established as first-line therapy on the basis of improved outcomes compared to first and second generation agents. However, despite excellent initial response rates, responses may not be durable due to the development of acquired resistance. Understanding these mechanisms of resistance is critical to the development of rational drug and drug combinations capable of circumventing them. We discuss the major mechanisms of resistance to first, second and third generation EGFR TKIs. The potential of drug combinations utilising chemotherapy, immunotherapy and anti-angiogenic drugs are explored. We examine strategies to aid drug development, including circulating tumour DNA and novel trial designs.

Targeting a neoantigen derived from a common TP53 mutation.

TP53 (tumor protein p53) is the most commonly mutated cancer driver gene, but drugs that target mutant tumor suppressor genes, such as TP53, are not yet available. Here, we describe the identification of an antibody highly specific to the most common TP53 mutation (R175H, in which arginine at position 175 is replaced with histidine) in complex with a common human leukocyte antigen-A (HLA-A) allele on the cell surface. We describe the structural basis of this specificity and its conversion into an immunotherapeutic agent: a bispecific single-chain diabody. Despite the extremely low p53 peptide-HLA complex density on the cancer cell surface, the bispecific antibody effectively activated T cells to lyse cancer cells that presented the neoantigen in vitro and in mice. This approach could in theory be used to target cancers containing mutations that are difficult to target in conventional ways.

Clonal expansion in non-cancer tissues.

Cancer is a clonal disorder derived from a single ancestor cell and its progenies that are positively selected by acquisition of 'driver mutations'. However, the evolution of positively selected clones does not necessarily imply the presence of cancer. On the contrary, it has become clear that expansion of these clones in phenotypically normal or non-cancer tissues is commonly seen in association with ageing and/or in response to environmental insults and chronic inflammation. Recent studies have reported expansion of clones harbouring mutations in cancer driver genes in the blood, skin, oesophagus, bronchus, liver, endometrium and bladder, where the expansion could be so extensive that tissues undergo remodelling of an almost entire tissue. The presence of common cancer driver mutations in normal tissues suggests a strong link to cancer development, providing an opportunity to understand early carcinogenic processes. Nevertheless, some driver mutations are unique to normal tissues or have a mutation frequency that is much higher in normal tissue than in cancer, indicating that the respective clones may not necessarily be destined for evolution to cancer but even negatively selected for carcinogenesis depending on the mutated gene. Moreover, tissues that are remodelled by genetically altered clones might define functionalities of aged tissues or modified inflammatory processes. In this Review, we provide an overview of major findings on clonal expansion in phenotypically normal or non-cancer tissues and discuss their biological significance not only in cancer development but also in ageing and inflammatory diseases.

Computational Analysis Finds Protein Stability-Related Cancer Mutations.

Putative cancer driver mutations affecting ubiquitin-proteasome system function were identified.

Protein dynamics analysis identifies candidate cancer driver genes and mutations in TCGA data.

Recently, it has been showed that cancer missense mutations selectively target the neighborhood of hinge residues, which are key sites in protein dynamics. Here, we show that this approach can be extended to find previously unknown candidate mutations and genes. To this aim, we developed a computational pipeline to detect significantly enriched three-dimensional (3D) clustering of missense mutations around hinge residues. The hinge residues were detected by applying a Gaussian network model. By systematically analyzing the PanCancer compendium of somatic mutations in nearly 10 000 tumors from the Cancer Genome Atlas, we identified candidate genes and mutations in addition to well known ones. For instance, we found significantly enriched 3D clustering of missense mutations in known cancer genes including CDK4, CDKN2A, TCL1A, and MAPK1. Beside these known genes, we also identified significantly enriched 3D clustering of missense mutations around hinge residues in PLA2G4A, which may lead to excessive phosphorylation of the extracellular signal-regulated kinases. Furthermore, we demonstrated that hinge-based features improves pathogenicity prediction for missense mutations. Our results show that the consideration of clustering around hinge residues can help us explain the functional role of the mutations in known cancer genes and identify candidate genes.

Abstract PD5-10: Mutational burden of the normal breast during age and pregnancy

Abstract Background: The potential for accumulation of somatic mutations in the healthy breast throughout life and pregnancy is poorly understood. In particular, the unique mutational landscape of both epithelial and stromal components of the mammary gland has not been investigated in depth. As cancer risk correlates with both age, age of first-time pregnancy and other factors including pregnancy itself, we wished to study mutational rate over time, using these landmarks. Methods: Here, using whole genome sequencing, we determined how the rate of mutations in both cancer drivers and passenger mutations are affected by both age and pregnancy. We aimed to describe for the first time how the mammary epithelium and stroma differ in their mutational burden. Results: Our analysis of epithelial and stromal laser-capture micro-dissected DNA from 25 normal breast samples of nulliparous and age-matched early- and late-parous women collected from Komen Tissue Bank, University of Indiana, shows that the mammary gland is characterised by known COSMIC signatures SBS1 and SBS5, both of which correlate with age (p&amp;lt;0.05). Using a non-negative matrix factorization approach, we identified a novel signature HB1 for a subset of samples which could not be fitted into the known signature database. Differences between the two cellular compartments were observed mostly in the enrichment pathway of mutated genes, notably a significant enrichment in mutations in the PI3K-Akt signalling pathway in the epithelium. We found that parous stroma is associated with a significant enrichment in mutations in the 3’UTR of genes, suggesting that regulation of the environment in the post-partum breast could preferably occur via these pathways. Alike other normal tissue, the mutational burden of the mammary gland significantly increases with age (P&amp;lt;0.05) and we observed parity-associated patterns of mutational burden, particularly evident in the epithelial compartment. The nulliparous epithelium is characterised by a significant increase of mutations (p&amp;lt;0.05), but mutated clones are maintained at a consistently small size. Conversely, the number of somatic mutations in the parous epithelium is not significantly affected by age, but age is positively correlated with bigger clone sizes (P&amp;lt;0.05) in this group. This trend suggests that possible cancer-associated mutations may have a lower probability of occurring but higher chance of expanding within the parous breast with age, compared to the nulliparous breast. To confirm this, we detected mutations in known driver genes in all the healthy samples, with some occurrence of known individual pathogenic variants.Conclusions: We show the mutational landscape of the healthy breast and highlight differences in the epithelial and stromal cellular compartments. We show how mutated cells, including mutations in driver genes for breast cancer, and genetic alterations change in the contest of pregnancy and age, provide a possible explanation for pregnancy-associated breast cancer risk. Citation Format: Biancastella Cereser, Neha Tabassum, Lisa Del Bel Belluz, Sladjana Zagorac, Angela Yiu, Philip Carter, Cristian Miere, Alicia R Jeffries-Jones, Justin Stebbing. Mutational burden of the normal breast during age and pregnancy [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD5-10.

Germline and Somatic Genetic Variants in the p53 Pathway Interact to Affect Cancer Risk, Progression, and Drug Response.

Insights into oncogenesis derived from cancer susceptibility loci (SNP) hold the potential to facilitate better cancer management and treatment through precision oncology. However, therapeutic insights have thus far been limited by our current lack of understanding regarding both interactions of these loci with somatic cancer driver mutations and their influence on tumorigenesis. For example, although both germline and somatic genetic variation to the p53 tumor suppressor pathway are known to promote tumorigenesis, little is known about the extent to which such variants cooperate to alter pathway activity. Here we hypothesize that cancer risk-associated germline variants interact with somatic TP53 mutational status to modify cancer risk, progression, and response to therapy. Focusing on a cancer risk SNP (rs78378222) with a well-documented ability to directly influence p53 activity as well as integration of germline datasets relating to cancer susceptibility with tumor data capturing somatically-acquired genetic variation provided supportive evidence for this hypothesis. Integration of germline and somatic genetic data enabled identification of a novel entry point for therapeutic manipulation of p53 activities. A cluster of cancer risk SNPs resulted in increased expression of prosurvival p53 target gene KITLG and attenuation of p53-mediated responses to genotoxic therapies, which were reversed by pharmacologic inhibition of the prosurvival c-KIT signal. Together, our results offer evidence of how cancer susceptibility SNPs can interact with cancer driver genes to affect cancer progression and identify novel combinatorial therapies. SIGNIFICANCE: These results offer evidence of how cancer susceptibility SNPs can interact with cancer driver genes to affect cancer progression and present novel therapeutic targets.

In This Issue

In This Issue

Arsenic and an Old Place: Rescuing p53 Mutants in Cancer

Tumor suppressor p53 lacks conventional drug binding pockets that would facilitate rescue of cancer-driving mutations. In this issue, Chen etal. discover a new role for an old drug, arsenic trioxide, in binding and stabilizing p53. The arsenic atom binds in a conserved, cryptic site and reactivates multiple p53 mutants.

Somatic Genomic Events in Endometriosis: Review of the Literature and Approach to Phenotyping.

In this review, we provide a survey and appraisal of research into somatic genomic events in endometriosis. Methodologies have evolved from conventional cytogenetics to next-generation sequencing, with findings ranging from chromosome imbalances to recurrent somatic cancer driver mutations. Somatic cancer driver mutations have been described in a range of endometriosis lesions, dominated by recurrent mutations in KRAS and PIK3CA as well as loss of PTEN and BAF250a (ARID1A). These somatic events appear to be largely restricted to the endometriosis glandular epithelium. Somatic mutations, particularly PTEN loss, have also been observed in eutopic (uterine) endometrium, although at lower mutant allele frequencies compared with ectopic lesions. Systematic studies of the potential clinical phenotype of these somatic genomic events have yet to be performed. Thus, we propose a framework to investigate the potential clinical phenotype associated with somatic genomic events in endometriosis. Technical requirements include pathology review of histological endometriosis, microdissection for tissue enrichment, orthogonal validation of whole genome/exome sequencing, and a germline sample for confirmation of somatic origin. Clinical requirements include annotation of surgical findings; patient demographics; cross-sectional and prospective data on pain and fertility; consideration of sampling multiple lesions in each patient, mutant allele frequency, and somatic events in the eutopic endometrium; and confirmation of any associations with mechanistic studies. Given the multifactorial nature of endometriosis-associated symptoms, it is likely that somatic events have small (or at most, moderate) effect sizes, and thus careful consideration will have to be given to future study design.

Prevalence and Spectrum of DICER1 Mutations in Adult-onset Thyroid Nodules with Indeterminate Cytology.

DICER1 mutations are found in multinodular goiter and differentiated thyroid carcinoma in children, and can be a manifestation of DICER1 syndrome, but the prevalence of DICER1 mutations and their significance in adult-onset thyroid nodules is unknown. Determine (1) the prevalence of DICER1 hotspot mutations in thyroid nodules; (2) the frequency of a second DICER1 pathogenic variant in thyroid nodules with DICER1 hotspot mutations; (3) the prevalence of other thyroid cancer driver mutations in thyroid nodules with and without DICER1 hotspot mutations. Population-based study of 14 993 consecutive fine needle aspiration biopsies of thyroid nodules evaluated by ThyroSeq v3. From 214 DICER1 hotspot-positive cases, we selected 61, matched to DICER1 hotspot-negative nodules. We performed full sequencing of all exons and exon-intron boundaries of DICER1. Commercial and university-based laboratories in the United States and Canada. Among 14 993 thyroid nodules, 214 (1.4%) revealed a DICER1 hotspot mutation. A second pathogenic/likely pathogenic variant in DICER1 was found in 45/59 (76%) DICER1 hotspot-positive nodules studied while no other DICER1 variant was identified in the DICER1 hotspot-negative group by full DICER1 sequencing. Other alterations in thyroid-related genes were significantly more frequent in DICER1 hotspot-negative nodules (32/61) than in DICER1 hotspot--positive nodules (4/59) (P < .0001). DICER1 alterations occur in a proportion of adult thyroid nodules and appear mutually exclusive with alterations in other thyroid cancer-related genes. DICER1 hotspot mutations occur with a second hit in most cases and could suggest occult DICER1 syndrome in adults with thyroid nodules.

CRISPR base editing applications for identifying cancer-driving mutations.

CRISPR base editing technology is a promising genome editing tool as (i) it does not require a DNA template to introduce mutations and (ii) it avoids creating DNA double-strand breaks, which can lead to unintended chromosomal alterations or elicit an unwanted DNA damage response. Given many cancers originate from point mutations in cancer-driving genes, the application of base editing for either modelling tumour development, therapeutic editing, or functional screening is of great promise. In this review, we summarise current DNA base editing technologies and will discuss recent advancements and existing hurdles for its usage in cancer research.