Project description:Setd2 is a histone H3K36 methyltransferase that suppresses lung cancer growth. Here we CRISPR knock out Setd2 in Kras-G12D genetically-engineered mouse models, and perform RNA-seq on FACS-purified neoplastic cells to profile the gene expression changes that result from Setd2 inactivation. Control group samples were transduced with inert sgRNAs. H3K36me3 immunoblot was performed to verify Setd2 knockout status.
Project description:Oncogenic STAT3 functions are known in various malignancies. We found that STAT3 plays an unexpected tumor suppressive role in KRAS-mutant non-small-cell-lung cancer (NSCLC). In mice, tissue-specific inactivation of Stat3 resulted in increased Kras (G12D)-driven NSCLC initiation and malignant progression leading to markedly reduced survival. Clinically, low STAT3 expression levels correlate with poor survival in human lung adenocarcinoma patients with smoking history. Consistently, KRAS-mutant lung tumors showed reduced STAT3 levels. Mechanistically, we show that STAT3 controls NFκB-induced IL-8-expression by sequestering NFκB in the cytoplasm while IL-8 in turn regulates myeloid tumor infiltration and tumor vascularization thereby promoting tumor progression. These results identify a novel STAT3-NFκB-IL-8 axis in KRAS-mutant NSCLC with therapeutic and prognostic relevance WT: Control lung; KRAS: Lung tumors expressing KRAS G12D; KRAS STAT3 KO: Lung tumors expressing KRAS G12D- STAT3 deficient; tumors of four mice pooled per sample
Project description:Oncogenic KRAS mutations are a key driver for initiation and progression in non-small-cell lung cancer (NSCLC). However, how post-translational modifications (PTMs) of KRAS, especially methylation, modify KRAS activity remain largely unclear. Here, we show that SET domain containing histone lysine methyltransferase 7 (SETD7) interacts with KRAS and methylates KRAS at lysines 182 and 184. SETD7-mediated methylation of KRAS leads to degradation of KRAS and attenuation of the RAS/MEK/ERK signaling cascade, endowing SETD7 with a potent tumor-suppressive role in NSCLC, both in vitro and in vivo. Mechanistically, RABGEF1, a ubiquitin E3 ligase of KRAS, was recruited and promoted KRAS degradation in a K182/K184 methylation-dependent manner. Notably, SETD7 is inversely correlated with KRAS at the protein level in clinical NSCLC tissues. Low SETD7 or RABGEF1 expression is associated with poor prognosis in lung adenocarcinoma patients. Altogether, our results elucidate a tumor-suppressive function of SETD7 that operates via modulating KRAS methylation and degradation.
Project description:Non-small cell lung cancer (NSCLC), the most frequent subtype of lung cancer, remains a highly lethal malignancy and one of the leading causes of cancer deaths worldwide. Mutant KRAS is the prevailing oncogenic driver of lung adenocarcinoma, the most common histological form of NSCLC. In this study, we examined the role of PKCe, an oncogenic kinase highly expressed in NSCLC and other cancers, in KRAS-driven tumorigenesis. Notably, database analysis revealed an association between PKCe expression and poor outcome in lung adenocarcinoma patients specifically having KRAS mutation. By generating a PKCe-deficient, conditionally activatable allele of oncogenic Kras (LSL-Kras G12D ;PKCe -/- mice) we were able to demonstrate the requirement of PKCe for Kras-driven lung tumorigenesis in vivo, which is consistent with the impaired transformed growth observed in PKCe-deficient KRAS-dependent NSCLC cells. Moreover, PKCe-knockout mice were found to be less susceptible to lung tumorigenesis induced by benzo[a]pyrene, a carcinogen that induces mutations in Kras. Mechanistic analysis using RNA-Seq revealed little overlapping for PKCe and KRAS in the control of genes/biological pathways relevant in NSCLC, suggesting that a permissive role of PKCe in KRAS-driven lung tumorigenesis may involve non-redundant mechanisms. Our results thus highlight the relevance and potential of targeting PKCe for lung cancer therapeutics.
Project description:RNA-sequencing analysis of murine KPY lung adenocarcinoma tumors in the presence and absence of Setd2. Tumors were harvested from KPY-Ctrl and KPY-SetdKO mice and were then subject to RNA-Seq to identify gene expression differences following loss of Setd2 expression.
Project description:RNA-sequencing analysis of murine K lung adenocarcinoma tumors in the presence and absence of Setd2. Tumors were harvested from K-Ctrl and K-Setd2KO mice. Tumors were then subject to RNA-Seq to identify gene expression differences following loss of Setd2 expression.