Project description:Kras-driven non-small-cell lung cancers (NSCLCs) are a leading cause of death with limited therapeutic options. Many NSCLCs exhibit high levels of Ezh2, the enzymatic subunit of polycomb repressive complex 2 (PRC2). We tested Ezh2 inhibitors as single agents or before chemotherapy in mice with orthotopic Kras-driven NSCLC grafts, which homogeneously express Ezh2. These tumors display sensitivity to EZH2 inhibition by GSK126 but also amplify an inflammatory program involving signaling through NF-?B and genes residing in PRC2-regulated chromatin. During this process, tumor cells overcome GSK126 antiproliferative effects. We identified oncogenes that may mediate progression through an in vivo RNAi screen aimed at targets of PRC2/NF-?B. An in vitro compound screening linked GSK126-driven inflammation and therapeutic vulnerability in human cells to regulation of RNA synthesis and proteostasis. Interestingly, GSK126-treated NSCLCs in vivo also showed an enhanced response to a combination of nimesulide and bortezomib. Thus, Ezh2 inhibition may restrict cell proliferation and promote defined adaptive responses. Targeting these responses potentially improves outcomes in Kras-driven NSCLCs.
Project description:Lung cancer is the leading cause of cancer-related human death. It is a heterogeneous disease, classified in two main histotypes, small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC), which is further subdivided into squamous-cell carcinoma (SCC) and adenocarcinoma (AD) subtypes. Despite the introduction of innovative therapeutics, mainly designed to specifically treat AD patients, the prognosis of lung cancer remains poor. In particular, available treatments for SCLC and SCC patients are currently limited to platinum-based chemotherapy and immune checkpoint inhibitors. In this work, we used an integrative approach to identify novel vulnerabilities in lung cancer. First, we compared the data from a CRISPR/Cas9 dependency screening performed in our laboratory with Cancer Dependency Map Project data, essentiality comprising information on 73 lung cancer cell lines. Next, to identify relevant therapeutic targets, we integrated dependency data with pharmacological data and TCGA gene expression information. Through this analysis, we identified CSNK1A1, KDM2A, and LTB4R2 as relevant druggable essentiality genes in lung cancer. We validated the antiproliferative effect of genetic or pharmacological inhibition of these genes in two lung cancer cell lines. Overall, our results identified new vulnerabilities associated with different lung cancer histotypes, laying the basis for the development of new therapeutic strategies.
Project description:Ras-driven tumors are often refractory to conventional therapies. Here we identify a promising targeted therapeutic strategy for two Ras-driven cancers: Nf1-deficient malignancies and Kras/p53 mutant lung cancer. We show that agents that enhance proteotoxic stress, including the HSP90 inhibitor IPI-504, induce tumor regression in aggressive mouse models, but only when combined with rapamycin. These agents synergize by promoting irresolvable ER stress, resulting in catastrophic ER and mitochondrial damage. This process is fueled by oxidative stress, which is caused by IPI-504-dependent production of reactive oxygen species, and the rapamycin-dependent suppression of glutathione, an important endogenous antioxidant. Notably, the mechanism by which these agents cooperate reveals a therapeutic paradigm that can be expanded to develop additional combinations.
Project description:The LKB1 tumour suppressor is a serine/threonine kinase that functions as master regulator of cell growth, metabolism, survival and polarity. LKB1 is frequently mutated in human cancers and research spanning the last two decades have begun decoding the cellular pathways deregulated following LKB1 inactivation. This work has led to the identification of vulnerabilities present in LKB1-deficient tumour cells. Pre-clinical studies have now identified therapeutic strategies targeting this subset of tumours that promise to benefit this large patient population harbouring LKB1 mutations. Here, we review the current efforts that are underway to translate pre-clinical discovery of therapeutic strategies targeting LKB1 mutant cancers into clinical practice.
Project description:The identification of molecular subtypes of non-small-cell lung cancer has transformed the clinical management of this disease. This is best exemplified by the clinical success of targeting the EGFR or ALK with tyrosine kinase inhibitors in the front-line setting. Our ability to further improve patient outcomes with biomarker-based targeted therapies will depend on a more comprehensive genetic platform that can rationally interrogate the cancer genome of an individual patient. Novel technologies, including multiplex genotyping and next-generation sequencing are rapidly evolving and will soon challenge the oncologist with a wealth of genetic information for each patient. Although there are many barriers to overcome, the integration of these genetic platforms into clinical care has the potential to transform the management of lung cancer through improved molecular categorization, patient stratification, and drug development, thereby, improving clinical outcomes through personalized lung cancer medicine.
Project description:The common participation of oncogenic KRAS proteins in many of the most lethal human cancers, together with the ease of detecting somatic KRAS mutant alleles in patient samples, has spurred persistent and intensive efforts to develop drugs that inhibit KRAS activity. However, advances have been hindered by the pervasive inter- and intra-lineage diversity in the targetable mechanisms that underlie KRAS-driven cancers, limited pharmacological accessibility of many candidate synthetic-lethal interactions and the swift emergence of unanticipated resistance mechanisms to otherwise effective targeted therapies. Here we demonstrate the acute and specific cell-autonomous addiction of KRAS-mutant non-small-cell lung cancer cells to receptor-dependent nuclear export. A multi-genomic, data-driven approach, utilizing 106 human non-small-cell lung cancer cell lines, was used to interrogate 4,725 biological processes with 39,760 short interfering RNA pools for those selectively required for the survival of KRAS-mutant cells that harbour a broad spectrum of phenotypic variation. Nuclear transport machinery was the sole process-level discriminator of statistical significance. Chemical perturbation of the nuclear export receptor XPO1 (also known as CRM1), with a clinically available drug, revealed a robust synthetic-lethal interaction with native or engineered oncogenic KRAS both in vitro and in vivo. The primary mechanism underpinning XPO1 inhibitor sensitivity was intolerance to the accumulation of nuclear IκBα (also known as NFKBIA), with consequent inhibition of NFκB transcription factor activity. Intrinsic resistance associated with concurrent FSTL5 mutations was detected and determined to be a consequence of YAP1 activation via a previously unappreciated FSTL5-Hippo pathway regulatory axis. This occurs in approximately 17% of KRAS-mutant lung cancers, and can be overcome with the co-administration of a YAP1-TEAD inhibitor. These findings indicate that clinically available XPO1 inhibitors are a promising therapeutic strategy for a considerable cohort of patients with lung cancer when coupled to genomics-guided patient selection and observation.
Project description:KRAS mutations are one of the most common oncogenic drivers in non-small cell lung cancer (NSCLC) and in lung adenocarcinomas in particular. Development of therapeutics targeting KRAS has been incredibly challenging, prompting indirect inhibition of downstream targets such as MEK and ERK. Such inhibitors, unfortunately, come with limited clinical efficacy, and therefore the demand for developing novel therapeutic strategies remains an urgent need for these patients. Exploring the influence of wild-type (WT) KRAS on druggable targets can uncover new vulnerabilities for the treatment of KRAS mutant lung adenocarcinomas. Using commercially available KRAS mutant lung adenocarcinoma cell lines, we explored the influence of WT KRAS on signaling networks and druggable targets. Expression and/or activation of 183 signaling proteins, most of which are targets of FDA-approved drugs, were captured by reverse-phase protein microarray (RPPA). Selected findings were validated on a cohort of 23 surgical biospecimens using the RPPA. Kinase-driven signatures associated with the presence of the KRAS WT allele were detected along the MAPK and AKT/mTOR signaling pathway and alterations of cell cycle regulators. FoxM1 emerged as a potential vulnerability of tumors retaining the KRAS WT allele both in cell lines and in the clinical samples. Our findings suggest that loss of WT KRAS impacts on signaling events and druggable targets in KRAS mutant lung adenocarcinomas.
Project description:The transcription factor NRF2 is a master regulator of the cellular antioxidant response, and it is often genetically activated in non-small-cell lung cancers (NSCLCs) by, for instance, mutations in the negative regulator KEAP1. While direct pharmacological inhibition of NRF2 has proven challenging, its aberrant activation rewires biochemical networks in cancer cells that may create special vulnerabilities. Here, we use chemical proteomics to map druggable proteins that are selectively expressed in KEAP1-mutant NSCLC cells. Principal among these is NR0B1, an atypical orphan nuclear receptor that we show engages in a multimeric protein complex to regulate the transcriptional output of KEAP1-mutant NSCLC cells. We further identify small molecules that covalently target a conserved cysteine within the NR0B1 protein interaction domain, and we demonstrate that these compounds disrupt NR0B1 complexes and impair the anchorage-independent growth of KEAP1-mutant cancer cells. Our findings designate NR0B1 as a druggable transcriptional regulator that supports NRF2-dependent lung cancers.
Project description:Links between oncogenic drivers and cancer cell metabolism have emerged over the past several decades, indicating that constitutive oncogenic growth signaling can render cancers susceptible to metabolic interventions. While significant progress has been achieved in the identification of metabolic vulnerabilities of cancer cells, the complexity of the tumor microenvironment (TME) and the dynamic nature of organismal circadian metabolism challenge the precision of targeting cancer metabolism. Here current progress in the areas of cancer metabolism and TME metabolism is reviewed, highlighting how cancer metabolism can be accurately and precisely targeted.
Project description:MicroRNA (miR) are important regulators of gene expression, and aberrant miR expression has been linked to oncogenesis; however, little is understood about their contribution to lung tumorigenesis. Here, we determined that miR-31 is overexpressed in human lung adenocarcinoma and this overexpression independently correlates with decreased patient survival. We developed a transgenic mouse model that allows for lung-specific expression of miR-31 to test the oncogenic potential of miR-31 in the lung. Using this model, we observed that miR-31 induction results in lung hyperplasia, followed by adenoma formation and later adenocarcinoma development. Moreover, induced expression of miR-31 in mice cooperated with mutant KRAS to accelerate lung tumorigenesis. We determined that miR-31 regulates lung epithelial cell growth and identified 6 negative regulators of RAS/MAPK signaling as direct targets of miR-31. Our study distinguishes miR-31 as a driver of lung tumorigenesis that promotes mutant KRAS-mediated oncogenesis and reveals that miR-31 directly targets and reduces expression of negative regulators of RAS/MAPK signaling.