Similar Datasets
Project description:Acquired resistance remains a major challenge for therapies targeting oncogene activated pathways. KRAS is the most frequently mutated oncogene in human cancers, yet strategies targeting its downstream signaling kinases have failed to produce durable treatment responses. Here, we developed multiple models of acquired resistance to dual-mechanism ERK/MAPK inhibitors across KRAS-mutant pancreatic, colorectal, and lung cancers, and then probed the long-term events enabling survival against this class of drugs. These studies revealed that resistance emerges secondary to large-scale transcriptional adaptations that are diverse and cell line-specific. Transcriptional reprogramming extends beyond the well-established early response, and instead represents a dynamic, evolved process that is refined to attain a stably resistant phenotype. Mechanistic and translational studies reveal that resistance to dual-mechanism ERK/MAPK inhibition is broadly susceptible to manipulation of the epigenetic machinery, and that Mediator kinase, in particular, can be co-targeted at a bottleneck point to prevent diverse, cell line-specific resistance programs.
| S-EPMC10635398 | biostudies-literature
Project description:KRAS mutations are among the most common drivers of human carcinogenesis, and are associated with poor prognosis and an aggressive disease course. With the advent of KRASG12C inhibitors, the RAS protein is now targetable, with such inhibitors showing marked clinical responses across multiple tumor types. However, these responses are short-lived due to the development of resistance. Preclinical studies now suggest MAPK reactivation, stimulation of CDK4/6-dependent cell-cycle transition, and immune defects as possible mechanisms of resistance. Devising strategies to overcome such resistance mechanisms, which are a barrier to long-term clinical response, remain an active area of research. SIGNIFICANCE: Although KRAS-targeted cancer therapy is revolutionary, tumors rapidly develop resistance. Understanding the mechanisms driving this resistance and designing combination strategies to overcome it are integral to achieving long-term disease control.
| S-EPMC8178176 | biostudies-literature
Project description:Acquired resistance remains a major challenge for therapies targeting oncogene activated pathways. KRAS, for example, is the most frequently mutated oncogene in human cancers, yet strategies targeting its downstream signaling kinases have failed to produce durable treatment responses. Here, we developed multiple models of acquired resistance to second-generation MAPK inhibitors across KRAS-mutant pancreatic, colorectal, and lung cancers, then probed the long-term events enabling survival against this class of drugs. These studies revealed that resistance emerges secondary to large-scale transcriptional adaptations that are diverse and tumor-specific. Transcriptional reprogramming extends beyond the well-established early response, and instead represents a dynamic, evolved process that is refined to attain a stably resistant phenotype. Mechanistic and translational studies reveal that resistance to sustained MAPK inhibition is broadly susceptible to manipulation of the epigenetic machinery, and that Mediator kinase, in particular, can be co-targeted at a bottleneck point to prevent diverse, tumor-specific resistance programs.
2024-06-26 | GSE234378 | GEO
Project description:Acquired resistance remains a major challenge for therapies targeting oncogene activated pathways. KRAS is the most frequently mutated oncogene in human cancers, yet strategies targeting its downstream signaling kinases have failed to produce durable treatment responses. Here, we developed multiple models of acquired resistance to dual-mechanism ERK/MAPK inhibitors across KRAS-mutant pancreatic, colorectal, and lung cancers, and then probed the long-term events enabling survival against this class of drugs. These studies revealed that resistance emerges secondary to large-scale transcriptional adaptations that are diverse and tumor-specific. Transcriptional reprogramming extends beyond the well-established early response, and instead represents a dynamic, evolved population-level process that is refined to attain a stably resistant phenotype. Mechanistic and translational studies reveal that resistance to dual-mechanism ERK/MAPK inhibition is broadly susceptible to manipulation of the epigenetic machinery, and that Mediator kinase, in particular, can be co-targeted at a bottleneck point to prevent diverse, tumor-specific resistance programs.
2024-05-15 | GSE237177 | GEO
Project description:Pancreatic ductal adenocarcinoma (PDAC) is still one of the deadliest cancers in oncology because of its increasing incidence and poor survival rate. More than 90% of PDAC patients are KRAS mutated (KRASmu), with KRASG12D and KRASG12V being the most common mutations. Despite this critical role, its characteristics have made direct targeting of the RAS protein extremely difficult. KRAS regulates development, cell growth, epigenetically dysregulated differentiation, and survival in PDAC through activation of key downstream pathways, such as MAPK-ERK and PI3K-AKT-mammalian target of rapamycin (mTOR) signaling, in a KRAS-dependent manner. KRASmu induces the occurrence of acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) and leads to an immunosuppressive tumor microenvironment (TME). In this context, the oncogenic mutation of KRAS induces an epigenetic program that leads to the initiation of PDAC. Several studies have identified multiple direct and indirect inhibitors of KRAS signaling. Therefore, KRAS dependency is so essential in KRASmu PDAC that cancer cells have secured several compensatory escape mechanisms to counteract the efficacy of KRAS inhibitors, such as activation of MEK/ERK signaling or YAP1 upregulation. This review will provide insights into KRAS dependency in PDAC and analyze recent data on inhibitors of KRAS signaling, focusing on how cancer cells establish compensatory escape mechanisms.
| S-EPMC10253344 | biostudies-literature
Project description:Oncogenic KRAS is now recognized as a viable target for drug intervention; nevertheless, the efficacy of KRAS-targeted therapy is impeded by various resistance mechanisms. The intricate interplay between cancer cells and the cells within the tumor microenvironment (TME) actively contributes to the mutual promotion of resistance to KRAS-targeted therapies. To discern specific cell populations orchestrating tumor responses in pancreatic ductal adenocarcinoma (PDAC), we conducted single-cell RNA sequencing (scRNA-seq) on spontaneous tumors obtained from genetically engineered mouse models. This analysis was performed both before and after the inhibition or genetic ablation of KRAS, shedding light on the dynamic changes occurring at the single-cell level.
2024-10-09 | GSE252834 | GEO
Project description:Despite the success of targeted therapies in cancer treatment, therapy-induced resistance remains a major obstacle to a complete cure. Tumor cells evade treatments and relapse via phenotypic switching driven by intrinsic or induced cell plasticity. Several reversible mechanisms have been proposed to circumvent tumor cell plasticity, including epigenetic modifications, regulation of transcription factors, activation or suppression of key signaling pathways, as well as modification of the tumor environment. Epithelial-to-mesenchymal transition, tumor cell and cancer stem cell formation also serve as roads towards tumor cell plasticity. Corresponding treatment strategies have recently been developed that either target plasticity-related mechanisms or employ combination treatments. In this review, we delineate the formation of tumor cell plasticity and its manipulation of tumor evasion from targeted therapy. We discuss the non-genetic mechanisms of targeted drug-induced tumor cell plasticity in various types of tumors and provide insights into the contribution of tumor cell plasticity to acquired drug resistance. New therapeutic strategies such as inhibition or reversal of tumor cell plasticity are also presented. We also discuss the multitude of clinical trials that are ongoing worldwide with the intention of improving clinical outcomes. These advances provide a direction for developing novel therapeutic strategies and combination therapy regimens that target tumor cell plasticity.
| S-EPMC10008648 | biostudies-literature
Project description:ATR (Ataxia Telangiectasia and Rad3-related) is a member of the Phosphatidylinositol 3-kinase-related kinases (PIKKs) family, amongst six other vertebrate proteins known so far. ATR is indispensable for cell survival and its essential role is in sensing DNA damage and initiating appropriate repair responses. In this review we highlight emerging and recent observations connecting ATR to alternative roles in controlling the nuclear envelope, nucleolus, centrosome and other organelles in response to both internal and external stress conditions. We propose that ATR functions control cell plasticity by sensing structural deformations of different cellular components, including DNA and initiating appropriate repair responses, most of which are yet to be understood completely.
| S-EPMC4962764 | biostudies-literature
Project description:Molecular mechanisms underlying adaptive targeted therapy resistance in pancreatic ductal adenocarcinoma (PDAC) are poorly understood. Here, we identify SETD5 as a major driver of PDAC resistance to MEK1/2 inhibition (MEKi). SETD5 is induced by MEKi resistance and its deletion restores refractory PDAC vulnerability to MEKi therapy in mouse models and patient-derived xenografts. SETD5 lacks histone methyltransferase activity but scaffolds a co-repressor complex, including HDAC3 and G9a. Gene silencing by the SETD5 complex regulates known drug resistance pathways to reprogram cellular responses to MEKi. Pharmacological co-targeting of MEK1/2, HDAC3, and G9a sustains PDAC tumor growth inhibition in vivo. Our work uncovers SETD5 as a key mediator of acquired MEKi therapy resistance in PDAC and suggests a context for advancing MEKi use in the clinic.
| S-EPMC8187079 | biostudies-literature
Project description:Oncogenic KRAS signaling is a hallmark of pancreatic ductal adenocarcinoma (PDAC), a lethal malignancy with few treatment options. A major roadblock in deploying therapies targeting the KRAS-MAPK pathway is the rapid emergence of resistant cancer cells. However, molecular mechanisms underlying adaptive targeted therapy resistance in PDAC are poorly understood. Here we find SETD5 (SET domain containing 5) as a major epigenetic driver of PDAC resistance to MEK1/2 inhibition (MEKi). SETD5 is identified in a genetic screen of annotated methyltransferases that mediate MEKi toxicity in PDAC cells. SETD5 expression is induced upon PDAC cells and tumors acquring MEKi-resistance and SETD5 deletion restores vulnerability of refractory PDAC to MEKi therapy in mouse models and patient-derived xenografts (PDX). SETD5 lacks intrinsic histone methyltransferase activity and rather scaffolds a distinct corepressor complex that regulates HDAC3 and G9a catalytic behaviors to couple selective deacetylation with methylation of histone H3 at lysine 9 (H3K9). Gene silencing by the SETD5 complex regulates a network of known drug resistance pathways to reprogram cellular responses to MEKi, a resistance program disrupted by G9a and HDAC3 blockade. Combinatorial pharmacological targeting of MEK1/2, G9a, and HDAC3 results in sustained tumor growth inhibition in murine and human models of PDAC. Together, our work uncovers SETD5 as a master epigenetic regulator of acquired MAPK-pathway therapy resistance and suggests an efficacious clinical path for MEKi in PDAC.
2020-05-06 | GSE142046 | GEO