Gene expression profile at single cell level of non-malignant cells in KRAS syngeneic mouse tumor models
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ABSTRACT: STK11/LKB1 mutation is a primary driver for immunotherapy resistance. We employed KRAS/LKB1 syngeneic mouse models by injecting tumor cells with Kras mutation, Kras/Stk11 mutation and MCT4 knockout. We used single-cell RNA-seq to analyze the impact of LKB1 deficiency on the immune microenvironment.
Project description:STK11/LKB1 and KEAP1 mutations are associated with immunotherapy resistance. We employed KRAS syngeneic mouse cells (K) and generated KEAP1 loss (KK) or STK11/KEAP1 loss (KLK) by CRISPR/KO. Then we injected these tumor cells and collected the tumor for single-cell RNA-seq. Our aim is to analyze the impact of STK11 and/or KEAP1 deficiency on the immune microenvironment.
Project description:Mutations in STK11/LKB1 in non-small cell lung cancer (NSCLC) are associated with poor patient responses to immune checkpoint blockade (ICB) and introduction of a Stk11/Lkb1 (L) mutation into murine lung adenocarcinomas driven by mutant Kras and Trp53 loss (KP) resulted in an ICB refractory syngeneic KPL tumor. Mechanistically this occurred because KPL mutant NSCLCs lacked TCF1-expressing CD8 T cells, a phenotype recapitulated in human STK11/LKB1 mutant NSCLCs. Systemic inhibition of Axl results in increased type I interferon secretion from dendritic cells that expanded tumor-associated TCF1+ PD-1+ CD8 T cells, restoring therapeutic response to PD-1 ICB for KPL tumors. This was observed in syngeneic immunocompetent mouse models and in humanized mice bearing STK11/LKB1 mutant NSCLC human tumor xenografts. NSCLC patients with identified STK11/LKB1 mutations receiving bemcentinib and pembrolizumab demonstrated objective clinical response to combination therapy. We conclude that AXL is a critical targetable driver of immune suppression in STK11/LKB1 mutant NSCLC.
Project description:While mutations in the KRAS oncogene are amongst the most prevalent in human cancer, there are few successful treatments to target these tumors. It is also likely that heterogeneity in KRAS-mutant tumor biology significantly contributes to the response to therapy. We hypothesized that presence of commonly co-occurring mutations in STK11 and TP53 tumor suppressors may represent a significant source of heterogeneity in KRAS-mutant tumors. To address this, we utilized a large cohort of resected tumors from 442 lung adenocarcinoma patients with data including annotation of prevalent driver mutations (KRAS, EGFR) and tumor suppressor mutations (STK11 and TP53), microarray-based gene expression and clinical covariates including overall survival (OS). Specifically, we determined impact of STK11 and TP53 mutations on a new KRAS mutation-associated gene expression signature as well as previously defined signatures of tumor cell proliferation and immune surveillance responses. Interestingly, STK11, but not TP53 mutations, were associated with highly elevated expression of KRAS mutation-associated genes. Mutations in TP53 and STK11 also impacted tumor biology regardless of KRAS status, with TP53 strongly associated with enhanced proliferation and STK11 with suppression of immune surveillance. These findings illustrate the remarkably distinct ways through which tumor suppressor mutations may contribute to heterogeneity in KRAS-mutant tumor biology. In addition, these studies point to novel associations between gene mutations and immune surveillance that could impact the response to immunotherapy.
Project description:The purpose of the experiment is to study the expression profiles variations upon the expression of the wild type isoform of LKB1 (STK11) in human lung carcinoma A459 cells. These cells are KRAS mutated and null for STK11. Cells were previously infected with the lentiviral construct pLenti-rtTA2-IRES-H2B-GFP doxycycline-inducible plasmid (obtained from S. Tenbaum, HG Palmer’s Lab Vall d´Hebron Institute of Oncology, VHIO) containing the human STK11wild type cDNA.
Project description:We performed RNA-sequencing of mouse cells derived from colony forming assays (CFA) to evaluate the transcriptome of MPN cells with deletion of the tumor suppressor STK11/LKB1 and relative controls. The CFA are from mouse primary floxed STK11 hematopoietic stem and progenitor cells (HSPCs) transduced with retroviruses encoding the MPN mutation MPLW515L and CRE recombinase to delete STK11.
Project description:Transcriptional profiling of BL/6 mice harboring a mutant Kras allele, with or without knockouts of Stk11 and/or Keap1, or with expression of an Nfe2l2 transgene, Nrf2Tg. In lung adenocarcinoma (LUAD), stabilization of the transcription factor NRF2 through genomic alterations in KEAP1 and NFE2L2 occurs in roughly a quarter of patients, often in the context of STK11 tumor suppressor loss. In this study, we demonstrate that NRF2 activation in the context of concurrent KRAS mutation and STK11 loss promotes aggressive LUAD tumor behavior in both human and mouse preclinical models. This phenotype is associated with metabolic rewiring and rescue by NRF2 of redox stress, high in STK11 null tumors. Applying a novel, pan-lung cancer, diagnostic NRF2 activation gene expression signature that is independent of frequently co-occurring mutations, we dissect the independent contributions of the three most frequent genetic events in human LUAD (NRF2 activation, STK11 loss and KRAS mutations) on patient prognosis and clinical responses in a dataset of second-line LUAD patients treated with immunotherapy or chemotherapy (OAK trial). Our findings underscore that both individual effects and epistatic relationships among oncogenic and tumor suppressor pathways influence tumor biology, immune contexture and patient clinical outcomes. Our work also highlights the value of lung cancer disease sub-classification based on genetic and expression profiling as part of patient clinical management.
Project description:Analysis of gene expression in LKB1(Stk11)-depleted sciatic nerves (LKB1-SCKO) vs control nerves from age-matched mice. Gene expression profiles are predominantly derived from Schwann cell glia and provide important information about the response of peripheral nerve Schwann cells to inactivation of the metabolic regulator protein LKB1(aka Stk11). Total RNA obtained from sciatic nerve segments from 6 LKB1-SCKO mutant mice compared to RNA from nerve segments from 6 control mice (floxed LKB1 mutant mice that do not express Cre recombinase).
Project description:Analysis of gene expression in LKB1(Stk11)-depleted sciatic nerves (LKB1-SCKO) vs control nerves from age-matched mice. Gene expression profiles are predominantly derived from Schwann cell glia and provide important information about the response of peripheral nerve Schwann cells to inactivation of the metabolic regulator protein LKB1(aka Stk11).
Project description:Heterozygous germ-line mutations in the LKB1 (STK11) gene cause Peutz-Jeghers syndrome (PJS), an autosomal dominant disorder characterized by hamartomatous polyposis of the gastrointestinal tract and an increased risk of colorectal, breast, ovarian, testicular and cervical cancer. To model the effects of LKB1 mutation in mammary tumourigenesis, we have used a conditional gene targeting strategy to generate a mouse in which exons 4-7 of the Lkb1 gene encoding the kinase domain of the protein are deleted specifically in the mammary gland. Mammary gland tumours arise in these mice with a latency of 46-85 weeks and occur in the thoracic or inguinal glands. These mammary gland tumours were characterised as Grade 2 invasive ductal carcinomas or solid papillary carcinomas and resemble those arising in PJS patients. This mouse model of Lkb1 deficiency provides a potentially useful tool to investigate the role of Lkb1 in tumourigenesis and to guide the development of therapeutic approaches