Unexpected oncosuppressive role for STAT3 in KRAS-induced lung tumorigenesis.
Ontology highlight
ABSTRACT:
SUBMITTER: Grabner B
PROVIDER: S-EPMC4909454 | biostudies-other | 2016 May
REPOSITORIES: biostudies-other
Similar Datasets
Project description:STAT3 is considered to play an oncogenic role in several malignancies including lung cancer; consequently, targeting STAT3 is currently proposed as therapeutic intervention. Here we demonstrate that STAT3 plays an unexpected tumour-suppressive role in KRAS mutant lung adenocarcinoma (AC). Indeed, lung tissue-specific inactivation of Stat3 in mice results in increased Kras(G12D)-driven AC initiation and malignant progression leading to markedly reduced survival. Knockdown of STAT3 in xenografted human AC cells increases tumour growth. Clinically, low STAT3 expression levels correlate with poor survival and advanced malignancy in human lung AC patients with smoking history, which are prone to KRAS mutations. Consistently, KRAS mutant lung tumours exhibit reduced STAT3 levels. Mechanistically, we demonstrate that STAT3 controls NF-κB-induced IL-8 expression by sequestering NF-κB within the cytoplasm, thereby inhibiting IL-8-mediated myeloid tumour infiltration and tumour vascularization and hence tumour progression. These results elucidate a novel STAT3-NF-κB-IL-8 axis in KRAS mutant AC with therapeutic and prognostic relevance.
| S-EPMC4366489 | biostudies-literature
Project description:The STAT3 transcription factor is an important regulator of stem cell self-renewal, cancer cell survival, and inflammation. In the pancreas, STAT3 is dispensable for normal development, whereas the majority of pancreatic ductal adenocarcinomas (PDAC) show constitutive activation of STAT3, suggesting its potential as a therapeutic target in this cancer. Here, we sought to define the mechanisms of STAT3 activation and its functional importance in PDAC pathogenesis. Large-scale screening of cancer cell lines with a JAK2 inhibitor that blocks STAT3 function revealed a more than 30-fold range in sensitivity in PDAC, and showed a close correlation of sensitivity with levels of tyrosine-phosphorylated STAT3 and of the gp130 receptor, an upstream signaling component. Correspondingly, upregulation of the IL6/LIF-gp130 pathway accounted for the strong STAT3 activation in PDAC subsets. To define functions of STAT3 in vivo, we developed mouse models that test the impact of conditional inactivation of STAT3 in KRAS-driven PDAC. We showed that STAT3 is required for the development of the earliest premalignant pancreatic lesions, acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN). Moreover, acute STAT3 inactivation blocked PDAC initiation in a second in vivo model. Our results show that STAT3 has critical roles throughout the course of PDAC pathogenesis, supporting the development of therapeutic approaches targeting this pathway. Moreover, our work suggests that gp130 and phospho-STAT3 expression may be effective biomarkers for predicting response to JAK2 inhibitors.
| S-EPMC3693754 | biostudies-literature
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
2015-02-05 | E-GEOD-52798 | biostudies-arrayexpress
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
2015-02-05 | GSE52798 | GEO
Project description:Dietary effects on tumor biology can be exploited to unravel cancer vulnerabilities. Here, we present surprising evidence for anti-proliferative action of high-calorie-diet (HCD) feeding on KRAS-driven lung tumors. Tumors of mice that commenced HCD feeding before tumor onset displayed defective unfolded protein response (UPR) and unresolved endoplasmic reticulum (ER) stress. Unresolved ER stress and reduced proliferation are reversed by chemical chaperone treatment. Whole-genome transcriptional analyses revealed FKBP10 as one of the most downregulated chaperones in tumors of the HCD-pre-tumor-onset group. FKBP10 downregulation dampens tumor growth in vitro and in vivo. Providing translational value to these results, we report that FKBP10 is expressed in human KRAS-positive and -negative lung cancers, but not in healthy parenchyma. Collectively, our data shed light on an unexpected anti-tumor action of HCD imposed before tumor onset and identify FKBP10 as a putative therapeutic target to selectively hinder lung cancer.
| S-EPMC4305190 | biostudies-literature
Project description:Mutant KRAS drives glycolytic flux in lung cancer, potentially impacting aberrant protein glycosylation. Recent evidence suggests aberrant KRAS drives flux of glucose into the hexosamine biosynthetic pathway (HBP). HBP is required for various glycosylation processes, such as protein N- or O-glycosylation and glycolipid synthesis. However, its function during tumorigenesis is poorly understood. One contributor and proposed target of KRAS-driven cancers is a developmentally conserved epithelial plasticity program called epithelial-mesenchymal transition (EMT). Here we showed in novel autochthonous mouse models that EMT accelerated KrasG12D lung tumorigenesis by upregulating expression of key enzymes of the HBP pathway. We demonstrated that HBP was required for suppressing KrasG12D-induced senescence, and targeting HBP significantly delayed KrasG12D lung tumorigenesis. To explore the mechanism, we investigated protein glycosylation downstream of HBP and found elevated levels of O-linked β-N-acetylglucosamine (O-GlcNAcylation) posttranslational modification on intracellular proteins. O-GlcNAcylation suppressed KrasG12D oncogene-induced senescence (OIS) and accelerated lung tumorigenesis. Conversely, loss of O-GlcNAcylation delayed lung tumorigenesis. O-GlcNAcylation of proteins SNAI1 and c-MYC correlated with the EMT-HBP axis and accelerated lung tumorigenesis. Our results demonstrated that O-GlcNAcylation was sufficient and required to accelerate KrasG12D lung tumorigenesis in vivo, which was reinforced by epithelial plasticity programs.
| S-EPMC6205381 | biostudies-literature
Project description:Oncogenic KRAS induces tumor onset and development by modulating gene expression via different molecular mechanisms. MicroRNAs (miRNAs) are small non-coding RNAs that have been established as main players in tumorigenesis. By overexpressing wild type or mutant KRAS (KRASG12D) and using inducible human and mouse cell lines, we analyzed KRAS-regulated microRNAs in non-small-cell lung cancer (NSCLC). We show that miR-30c and miR-21 are significantly upregulated by both KRAS isoforms and induce drug resistance and enhance cell migration/invasion via inhibiting crucial tumor suppressor genes, such as NF1, RASA1, BID, and RASSF8. MiR-30c and miR-21 levels were significantly elevated in tumors from patients that underwent surgical resection of early stages NSCLC compared to normal lung and in plasma from the same patients. Systemic delivery of LNA-anti-miR-21 in combination with cisplatin in vivo completely suppressed the development of lung tumors in a mouse model of lung cancer. Mechanistically, we demonstrated that ELK1 is responsible for miR-30c and miR-21 transcriptional activation by direct binding to the miRNA proximal promoter regions. In summary, our study defines that miR-30c and miR-21 may be valid biomarkers for early NSCLC detection and their silencing could be beneficial for therapeutic applications.
| S-EPMC5833396 | biostudies-literature
Project description:A dichotomy exists regarding the role of signal transducer and activator of transcription 3 (STAT3) in cancer. Functional and genetic studies demonstrate either an intrinsic requirement for STAT3 or a suppressive effect on common types of cancer. These contrasting actions of STAT3 imply context dependency. To examine mechanisms that underlie STAT3 function in cancer, we evaluated the impact of STAT3 activity in KRAS-driven lung and pancreatic cancer. Our study defines a fundamental and previously unrecognized function of STAT3 in the maintenance of epithelial cell identity and differentiation. Loss of STAT3 preferentially associates with the acquisition of mesenchymal-like phenotypes and more aggressive tumor behavior. In contrast, persistent STAT3 activation through Tyr705 phosphorylation confers a differentiated epithelial morphology that impacts tumorigenic potential. Our results imply a mechanism in which quantitative differences of STAT3 Tyr705 phosphorylation, as compared with other activation modes, direct discrete outcomes in tumor progression.
| S-EPMC6120712 | biostudies-literature
Project description:KRAS mutant lung cancers are generally refractory to chemotherapy as well targeted agents. To date, the identification of drugs to therapeutically inhibit K-RAS have been unsuccessful, suggesting that other approaches are required. We demonstrate in both a novel transgenic mutant Kras lung cancer mouse model and in human lung tumors that the inhibition of Twist1 restores a senescence program inducing the loss of a neoplastic phenotype. The Twist1 gene encodes for a transcription factor that is essential during embryogenesis. Twist1 has been suggested to play an important role during tumor progression. However, there is no in vivo evidence that Twist1 plays a role in autochthonous tumorigenesis. Through two novel transgenic mouse models, we show that Twist1 cooperates with Kras(G12D) to markedly accelerate lung tumorigenesis by abrogating cellular senescence programs and promoting the progression from benign adenomas to adenocarcinomas. Moreover, the suppression of Twist1 to physiological levels is sufficient to cause Kras mutant lung tumors to undergo senescence and lose their neoplastic features. Finally, we analyzed more than 500 human tumors to demonstrate that TWIST1 is frequently overexpressed in primary human lung tumors. The suppression of TWIST1 in human lung cancer cells also induced cellular senescence. Hence, TWIST1 is a critical regulator of cellular senescence programs, and the suppression of TWIST1 in human tumors may be an effective example of pro-senescence therapy.
| S-EPMC3360067 | biostudies-literature
Project description:KRAS is the most frequently mutated driver oncogene in human adenocarcinoma of the lung. There are presently no clinically proven strategies for treatment of KRAS-driven lung cancer. Activating mutations in KRAS are thought to confer independence from upstream signaling; however, recent data suggest that this independence may not be absolute. We show that initiation and progression of KRAS-driven lung tumors require input from ERBB family receptor tyrosine kinases (RTKs): Multiple ERBB RTKs are expressed and active from the earliest stages of KRAS-driven lung tumor development, and treatment with a multi-ERBB inhibitor suppresses formation of KRASG12D-driven lung tumors. We present evidence that ERBB activity amplifies signaling through the core RAS pathway, supporting proliferation of KRAS-mutant tumor cells in culture and progression to invasive disease in vivo. Brief pharmacological inhibition of the ERBB network enhances the therapeutic benefit of MEK (mitogen-activated protein kinase kinase) inhibition in an autochthonous tumor setting. Our data suggest that lung cancer patients with KRAS-driven disease may benefit from inclusion of multi-ERBB inhibitors in rationally designed treatment strategies.
| S-EPMC6881183 | biostudies-literature