Similar Datasets
Project description:Oncogenic RAS/MAPK signaling drives metastatic squamous cell carcinomas (SCCs). These cancers are typified by high mutational burden, often featuring activating mutations in phosphatidylinositol-3-kinase (PI3K). Here we show that early in skin HRASG12V-induced oncogenesis, transitions from benign to malignant states are also marked by PI3K, this time super-activated through a temporal cascade of non-genetic events. Coupling clonal skin SCC genetic models with bulk and single-cell transcriptomics, chromatin-landscaping, lentiviral reporters, and lineage-tracing, we trace its roots. We show that following HRASG12V activation, oncogenic stem cells rewire their gene expression program. Initially, they produce an array of angiogenic factors, triggering a striking influx of vasculature and TGFβ into the microenvironment. Sparked by TGFβ-signaling, the stem cells induce leptin receptor (LEPR), which through the angiogenic influx activates LEPR-signaling to launch downstream PI3K-AKT-mTOR signaling. Our findings show how dynamic temporal crosstalk with the microenvironment, orchestrated by the stem cells, can drive the path to malignancy.
2022-10-09 | GSE207975 | GEO
Project description:Oncogenic RAS/MAPK signaling drives metastatic squamous cell carcinomas (SCCs). These cancers are typified by high mutational burden, often featuring activating mutations in phosphatidylinositol-3-kinase (PI3K). Here we show that early in skin HRASG12V-induced oncogenesis, transitions from benign to malignant states are also marked by PI3K, this time super-activated through a temporal cascade of non-genetic events. Coupling clonal skin SCC genetic models with bulk and single-cell transcriptomics, chromatin-landscaping, lentiviral reporters, and lineage-tracing, we trace its roots. We show that following HRASG12V activation, oncogenic stem cells rewire their gene expression program. Initially, they produce an array of angiogenic factors, triggering a striking influx of vasculature and TGFβ into the microenvironment. Sparked by TGFβ-signaling, the stem cells induce leptin receptor (LEPR), which through the angiogenic influx activates LEPR-signaling to launch downstream PI3K-AKT-mTOR signaling. Our findings show how dynamic temporal crosstalk with the microenvironment, orchestrated by the stem cells, can drive the path to malignancy.
2022-10-09 | GSE190414 | GEO
Project description:Oncogenic RAS/MAPK signaling drives metastatic squamous cell carcinomas (SCCs). These cancers are typified by high mutational burden, often featuring activating mutations in phosphatidylinositol-3-kinase (PI3K). Here we show that early in skin HRASG12V-induced oncogenesis, transitions from benign to malignant states are also marked by PI3K, this time super-activated through a temporal cascade of non-genetic events. Coupling clonal skin SCC genetic models with bulk and single-cell transcriptomics, chromatin-landscaping, lentiviral reporters, and lineage-tracing, we trace its roots. We show that following HRASG12V activation, oncogenic stem cells rewire their gene expression program. Initially, they produce an array of angiogenic factors, triggering a striking influx of vasculature and TGFβ into the microenvironment. Sparked by TGFβ-signaling, the stem cells induce leptin receptor (LEPR), which through the angiogenic influx activates LEPR-signaling to launch downstream PI3K-AKT-mTOR signaling. Our findings show how dynamic temporal crosstalk with the microenvironment, orchestrated by the stem cells, can drive the path to malignancy.
2022-10-09 | GSE190411 | GEO
Project description:We describe a mechanism of tumorigenesis mediated by kinase-dead BRAF in the presence of oncogenic RAS. We show that drugs that selectively inhibit BRAF drive RAS-dependent BRAF binding to CRAF, CRAF activation, and MEK-ERK signaling. This does not occur when oncogenic BRAF is inhibited, demonstrating that BRAF inhibition per se does not drive pathway activation; it only occurs when BRAF is inhibited in the presence of oncogenic RAS. Kinase-dead BRAF mimics the effects of the BRAF-selective drugs and kinase-dead Braf and oncogenic Ras cooperate to induce melanoma in mice. Our data reveal another paradigm of BRAF-mediated signaling that promotes tumor progression. They highlight the importance of understanding pathway signaling in clinical practice and of genotyping tumors prior to administering BRAF-selective drugs, to identify patients who are likely to respond and also to identify patients who may experience adverse effects.
| S-EPMC2872605 | biostudies-literature
Project description:Crosstalk between different receptor tyrosine kinases (RTKs) is thought to drive oncogenic signaling and allow therapeutic escape. EGFR and RON are two such RTKs from different subfamilies, which engage in crosstalk through unknown mechanisms. We combined high-resolution imaging with biochemical and mutational studies to ask how EGFR and RON communicate. EGF stimulation promotes EGFR-dependent phosphorylation of RON, but ligand stimulation of RON does not trigger EGFR phosphorylation - arguing that crosstalk is unidirectional. Nanoscale imaging reveals association of EGFR and RON in common plasma membrane microdomains. Two-color single particle tracking captured formation of complexes between RON and EGF-bound EGFR. Our results further show that RON is a substrate for EGFR kinase, and that transactivation of RON requires formation of a signaling competent EGFR dimer. These results support a role for direct EGFR/RON interactions in propagating crosstalk, such that EGF-stimulated EGFR phosphorylates RON to activate RON-directed signaling.
| S-EPMC8654365 | biostudies-literature
Project description:Inflammatory and autophagy-related gene P62 is highly expressed in most human tumor tissues. Herein, we demonstrate that P62 promotes human mesenchymal stem cells' malignant transformation via the cascade of P62-tumor necrosis factor alpha (TNF-α)-CUDR-CTCF-insulin growth factor II (IGFII)-H-Ras signaling. Mechanistically, we reveal P62 enhances IGFII transcriptional activity through forming IGFII promoter-enhancer chromatin loop and increasing METTL3 occupancy on IGFII 3' UTR and enhances H-Ras overexpression by harboring inflammation-related factors, e.g., TNFR1, CLYD, EGR1, NFκB, TLR4, and PPARγ. Furthermore, the P62 cooperates with TNF-α to promote malignant transformation of mesenchymal stem cells. These findings, for the first time, provide insight into the positive role that P62 plays in malignant transformation of mesenchymal stem cells and reveal a novel link between P62 and the inflammation factors in mesenchymal stem cells.
| S-EPMC5992448 | biostudies-literature
Project description:Here we study the effects of inducible oncogenic K-Ras (G12V) expression on the polarized morphogenesis of colonic epithelial cells. We provide evidence that the autocrine production of heregulins, ligands for the ErbB3 receptor tyrosine kinase, is responsible for the hyperproliferation and aberrant 3D morphogenesis upon oncogenic K-Ras expression. This is in line with results obtained in primary intestinal organoid cultures, in which exogenous heregulin is shown to interfere with normal tissue architecture. Importantly, ErbB3 inhibition and heregulin gene silencing rescued K-RasG12V-induced features of cell transformation. Together with the increased ErbB3 positivity detected in human high-grade primary colorectal cancers, our findings provide support for an autocrine signaling loop engaged by oncogenic K-Ras involving ErbB3 that contributes to the dedifferentiation of the intestinal epithelium during tumor initiation and progression.
| S-EPMC5288203 | biostudies-other
Project description:During the initial stages of tumorigenesis, the tissue microenvironment where the pro-tumor cells reside plays a crucial role in determining the fate of these cells. Transition zones, where two types of epithelial cells meet, are high-risk sites for carcinogenesis, but the underlying mechanism remains largely unclear. Here, we show that persistent upregulation of Notch signaling induces neoplastic tumorigenesis in a transition zone between the salivary gland imaginal ring cells and the giant cells in Drosophila larvae. In this region, local endogenous JAK-STAT and JNK signaling creates a tissue microenvironment that is susceptible to oncogenic-Notch-induced tumorigenesis, whereas the rest of the salivary gland imaginal ring is refractory to Notch-induced tumor transformation. JNK signaling activates a matrix metalloprotease (MMP1) to promote Notch-induced tumorigenesis at the transition zone. These findings illustrate the significance of local endogenous inflammatory signaling in primary tumor formation.
| S-EPMC6504601 | biostudies-literature
Project description:The Mig10/RIAM/Lpd (MRL) adapter protein Lpd regulates actin dynamics through interactions with Scar/WAVE and Ena/VASP proteins to promote the formation of cellular protrusions and to stimulate invasive migration. However, the ability of MRL proteins to interact with multiple actin regulators and to promote serum response factor (SRF) signalling has raised the question of whether MRL proteins employ alternative downstream mechanisms to drive oncogenic processes in a context-dependent manner. Here, using a Drosophila model, we show that overexpression of either human Lpd or its Drosophila orthologue Pico can promote growth and invasion of RasV12-induced cell tumours in the brain. Notably, effects were restricted to two populations of Repo-positive glial cells: an invasive population, characterized by JNK-dependent elevation of Mmp1 expression, and a hyperproliferative population lacking elevated JNK signalling. JNK activation was not triggered by reactive immune cell signalling, implicating the involvement of an intrinsic stress response. The ability to promote dissemination of RasV12-induced tumours was shared by a subset of actin regulators, including, most prominently, Chicadee/Profilin, which directly interacts with Pico, and, Mal, a cofactor for serum response factor that responds to changes in G:F actin dynamics. Suppression of Mal activity partially abrogated the ability of pico to promote invasion of RasV12 tumours. Furthermore, we found that larval glia are enriched for serum response factor expression, explaining the apparent sensitivity of glial cells to Pico/RasV12 overexpression. Taken together, our findings indicate that MRL proteins cooperate with oncogenic Ras to promote formation of glial tumours, and that, in this context, Mal/serum response factor activation is rate-limiting for tumour dissemination.
| S-EPMC5537612 | biostudies-literature
Project description:Several evidences nowadays demonstrated the critical role of the microenvironment in regulating cancer stem cells and their involvement in tumor progression. Extracellular vesicles (EVs) are considered as one of the most effective vehicles of information among cells. Accordingly, a number of studies led to the recognition of stem cell-associated EVs as new complexes able to contribute to cell fate determination of either normal or tumor cells. In this review, we aim to highlight an existing bidirectional role of EV-mediated communication-from cancer stem cells to microenvironment and also from microenvironment to cancer stem cells-in the most widespread solid cancers as prostate, breast, lung, and colon tumors.
| S-EPMC6247433 | biostudies-other