Project description:To profile the molecular changes in the lung during osteosarcoma pre-metastatic niche formation, we performed RNA-seq of lungs harvested from D0 and D14 after orthotopic implantation of K7M2 cells in balb/c mice.
Project description:Pancreatic cancers (PCs) are highly metastatic with poor prognosis, mainly due to delayed detection. We hypothesized that intercellular communication is critical for metastatic progression. Here, we show that PC-derived exosomes induce liver pre-metastatic niche formation in naïve mice and consequently increase liver metastatic burden. Uptake of PC-derived exosomes by Kupffer cells caused transforming growth factor β secretion and upregulation of fibronectin production by hepatic stellate cells. This fibrotic microenvironment enhanced recruitment of bone marrow-derived macrophages. We found that macrophage migration inhibitory factor (MIF) was highly expressed in PC-derived exosomes, and its blockade prevented liver pre-metastatic niche formation and metastasis. Compared to patients whose pancreatic tumors did not progress, MIF was markedly higher in exosomes from stage I PC patients who later developed liver metastasis. These findings suggest that exosomal MIF primes the liver for metastasis and may be a prognostic marker for the development of PC liver metastasis.
Project description:To investigate the molecular and cellular alterations occurring in the lung tissue during the pre-metastatic niche formation in osteosarcoma, we used two two experimental mouse models and a multi-omics approach.
Project description:To investigate the molecular and cellular alterations occurring in the lung tissue during the pre-metastatic niche formation in osteosarcoma, we used two different approaches in which mice were implanted subcutaneously with the 143B OS cells for a primary tumour (PT) formation or treated with the 143B cell-derived secretome (SCR) to mimic the release of secreted factors by a locally primary tumour.
Project description:Here we report an enzyme-activatable assembled peptide FR17 that can serve as a “flame-retarding blanket” at pre-metastatic niche (PMN) specifically to extinguish the “fire” of tumor-supportive microenvironment adaption. Our experiment demonstrated that the assembled peptide successfully reversed extracellular matrix deposition, vascular leakage and angiogenesis through inhibition on fibroblasts activation in PMN, which suppressed the remodeling of metastasis-supportive host stromal, and further prevented the recruitment of myeloid cells to PMN and then recovered the immunosuppressive microenvironment. Cell transcriptomic analysis of the pulmonary recruited MDSC suggested that FR17 intervention could regulate immune response activation, immune cells chemotaxis and migration pathways. Consequently, FR17 administration effectively inhibited pulmonary PMN formation and postoperative metastasis of melanoma, with only 30% lung-metastasis occurrence was observed for FR17 treated group at the time point when 100% occurrence was observed for the control group and 80% occurrence for anti-PD1 treated group, offering a robust therapeutic strategy against PMN establishing to prevent metastasis.
Project description:We performed transcriptome sequencing on epithelial cells, isolated from lungs of normal and tumor-bearing mice, to shed light on the function and phenotype changes of lung epithelial cells in the pre-metastatic niche.
Project description:Through an integrated transcriptome analysis of orthotopic colorectal cancer tumor-bearing mice and sham-operation mice, we showed the distinct immune microenvironment of pre-metastatic liver and identified MDSCs as the dominated cell type mediating pre-metastatic niche formation. MDSCs instead of other immune cell types were highly infiltrated in the pre-metastatic liver when compared with normal liver. Notably, immunosuppressive factors released by MDSCs such as HIF1α, iNOS, TGFβ were significantly up-regulated in the pre-metastatic liver. Increasing immune checkpoint molecules expression also reflected an immunosuppressive condition of pre-metastatic liver. The primary tumor may induce MDSCs accumulation via metabolic mechanism including glycolysis/gluconeogenesis, HIF-1 signaling pathway, and CCL28 chemokine axis. This study depicts the immune cell landscape of pre-metastatic cancer and primary CRC tumor, and provides insights into how MDSCs reshape the pre-metastatic niche facilitating circulating cancer cells colonization.
Project description:Extracellular vesicles (EVs) secreted by tumor cells are able to establish a pre-metastatic niche in distant organs, or on the contrary, exert anti-tumor activity. The mechanisms directing distinct EV functions are unknown. Using the B-16V transplantation mouse melanoma model we demonstrate that EVs from B-16V cells mobilize Ly6Clow patrolling monocytes and inhibit lung metastasis. Mechanistically, the formation of anti-tumor-EVs was dependent on the chaperone BAG6 and the acetylation of p53 by the BAG6/CBP/p300-acetylase complex, followed by the recruitment of components of the endosomal sorting complexes required for transport (ESCRT) via a P(S/T)AP double motif of BAG6. By contrast, deficiency of BAG6 led to the release of a distinct vesicle subtype with pro-tumorigenic activity, which recruited neutrophils to the pre-metastatic niche. In humans, BAG6 expression decreases in late-stage melanoma patients, correlating with an increase of the mRNA for the metastasis driver alpha-catulin in EVs, as observed in BAG6-deficient mouse EVs. We conclude that the BAG6/CBP/p300-p53 axis is a key pathway directing EV-formation and function.
Project description:The liver is the most common site of metastatic disease in gastrointestinal malignancies, including pancreatic ductal adenocarcinoma (PDAC). While this metastatic tropism may reflect mechanical trapping of tumor cells that enter the circulation, liver metastasis is also dependent, at least in part, on the formation of a “pro-metastatic” niche that supports tumor cell seeding and colonization in the liver. However, mechanisms that orchestrate the establishment of this niche are poorly understood. Here, we show that hepatocytes coordinate accumulation of myeloid cells and fibrosis within the liver, the two defining features of a pro-metastatic niche. Early during pancreatic tumorigenesis in mice, hepatocytes demonstrate activation of Signal Transducer and Activator of Transcription 3 (STAT3) signaling and increased production of serum amyloid A1 and A2 (SAA). Overexpression of SAA by hepatocytes also occurs in PDAC patients with liver metastases, and many patients with locally advanced and metastatic disease display elevated levels of circulating SAA. STAT3 activation in hepatocytes and the subsequent production of SAA are dependent on interleukin 6 (IL-6) that is released into the circulation by non-malignant cells that reside adjacent to malignant cells in the pancreas. Genetic ablation or blockade of components of IL-6/STAT3/SAA signaling in hepatocytes effectively prevents the establishment of a pro-metastatic niche and inhibits metastatic seeding in the liver. Collectively, our data reveal an intercellular network underpinned by hepatocytes that forms the basis for a pro-metastatic niche in the liver and identify new therapeutic targets for pancreatic cancer.