Pre-metastatic Niche Formation Research Articles

Fibrinogen: a new player and target on the formation of pre-metastatic niche in tumor metastasis.

Tumor metastasis involves a series of complex and coordinated processes, which is the main cause of patient death and still a significant challenge in cancer treatment. Pre-metastatic niches (PMN), a specialized microenvironment that develops in distant organs prior to the arrival of metastatic cancer cells, plays a crucial role in driving tumor metastasis. The development of PMN depends on a complex series of cellular and molecular components including tumor-derived factors, bone marrow-derived cells, resident immune cells, and extracellular matrix. Fibrinogen, a key factor in the typical blood clotting process, is related to tumor metastasis and prognosis, according to a growing body of evidence in recent years. Fibrinogen has emerged as an important factor in mediating the formation of tumor microenvironment. Nevertheless, a clear and detailed mechanism by which fibrinogen promotes tumor metastasis remains unknown. In this review, we first explore the roles of fibrinogen in the development of PMN from four perspectives: immunosuppression, inflammation, angiogenesis, and extracellular matrix remodeling. We highlight the significance of fibrinogen in shaping PMN and discuss its potential therapeutic values, opening new avenues for targeting fibrinogen to prevent or treat metastasis.

Neutrophil extracellular traps promote pre-metastatic niche formation in the omentum by expanding innate-like B cells that express IL-10.

Disseminated cancer cells in the peritoneal fluid often colonize omental fat-associated lymphoid clusters but the mechanisms are unclear. Here, we identify that innate-like B cells accumulate in the omentum of mice and women with early-stage ovarian cancer concomitantly with the extrusion of chromatin fibers by neutrophils called neutrophil extracellular traps (NETs). Studies using genetically modified NET-deficient mice, pharmacologic inhibition of NETs, and adoptive B cell transfer show that NETs induce expression of the chemoattractant CXCL13 in the pre-metastatic omentum, stimulating recruitment of peritoneal innate-like B cells that in turn promote expansion of regulatory Tcells and omental metastasis through producing interleukin (IL)-10. Exvivo studies show that NETs elicit IL-10 production in innate-like B cells by inactivating SHP-1, a phosphatase that inhibits B cell activation pathways, and by generating reactive oxygen species. These findings reveal that NETs alter immune cell dynamics in the pre-metastatic omentum, rendering this niche conducive for colonization.

Immune Cell Profiling Reveals a Common Pattern in Premetastatic Niche Formation Across Various Cancer Types

ABSTRACTBackgroundMetastasis is the major cause of cancer‐related mortality. The premetastatic niche is a promising target for its prevention. However, the generality and cellular dynamics in premetastatic niche formation have remained unclear.AimsThis study aimed to elucidate the generality and cellular dynamics in premetastatic niche formation.Materials and MethodsWe performed comprehensive flow cytometric analysis of lung and peripheral immune cells at three time points (early premetastatic, late premetastatic, and micrometastatic phases) for mice with subcutaneous implants of three types of cancer cells (breast cancer, lung cancer, or melanoma cells). The immuno‐cell profiles were then used to predict the metastatic phase by machine learning.ResultsWe found a common pattern of changes in both lung and peripheral immune cell profiles across the three cancer types, including a decrease in the proportion of eosinophils in the early premetastatic phase, an increase in that of regulatory T cells in the late premetastatic phase, and an increase in that of polymorphonuclear myeloid‐derived suppressor cells and a decrease in that of B cells in the micrometastatic phase. Machine learning using immune cell profiles could predict the metastatic phase with approximately 75% accuracy.DiscussionValidation of our findings in humans will require data on the presence or absence of micrometastases in patients and the accumulation of comprehensive and temporal information on immune cells. In addition, blood proteins, extracellular vesicles, DNA, RNA, or metabolites may be useful for more accurate prediction.ConclusionThe discovery of generalities in premetastatic niche formation allow prediction of metastatic phase and provide a basis for the development of methods for early detection and prevention of cancer metastasis in a cancer type‐independent manner.

Pulmonary lysyl oxidase expression and its role in seeding Lewis lung carcinoma cells.

Copper promotes tumor growth and metastasis through a variety of mechanisms, most notably as a cofactor within the lysyl oxidase (LOX) family of secreted cuproenzymes. Members of this family, which include LOX and LOX-like enzymes LOXL1-4, catalyze the copper-dependent crosslinking of collagens and elastin within the extracellular matrix (ECM). Elevated LOX expression is associated with higher incidence and worse prognosis in multiple cancers, including colorectal, breast, pancreatic, and head and neck. In this study, we demonstrated that elevated LOX expression correlates with decreased overall survival and shorter median time to first progression in patients with lung cancer. Previous studies have demonstrated that LOX secreted from tumors is critical for pre-metastatic niche formation by promoting ECM remodeling and the recruitment of immune cells and endothelial precursors. Here, we demonstrated that ablation of the LOX gene in Lewis lung carcinoma (LLC) cells diminishes tumor growth and metastasis compared to wild-type LLC cells in a syngeneic mouse model. Although the role of tumor-derived LOX in tumor formation and metastasis is well established, little is known regarding the possible contribution of LOX produced by the parenchymal tissue of metastatic organs. Thus, this report describes our findings that host-derived LOX produced by the lung contributes to the pulmonary metastasis of LLC cells in mice. The suppression of pulmonary lysyl oxidase expression reduces the metastatic potential of Lewis Lung Carcinoma cells in mice, revealing a previously unknown influence of LOX expression in the parenchymal tissue of metastatic target organs on the seeding of tumor cells.

Salivary adenoid cystic carcinoma-derived α2,6-sialylated extracellular vesicles increase vascular permeability by triggering ER-stress in endothelial cells and promote lung metastasis.

Salivary adenoid cystic carcinoma (SACC) tends to metastasize to the lungs in the early stages of the disease. Factors secreted by the primary tumor can induce the formation of a supportive microenvironment in distant organs prior to metastasis, a process known as pre-metastatic niche (PMN) formation. Extracellular vesicles (EVs) participate in PMN formation. In this study, α2,6-sialylation of EVs derived from SACC cells with high metastatic potential increased vascular permeability, thereby facilitating tumor metastasis to the lungs. Mechanistic studies indicated that EV α2,6-sialylation triggers protein kinase R-like endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor 2α (eIF2α)-dependent activation of endoplasmic reticulum (ER) stress in the endothelium, leading to the disruption of vascular endothelial cadherin membrane expression. Sialidase or an ER stress inhibitor rescued vascular permeability induced by SACC EVs, which decreased the number of SACC cells extravasating into the lungs both in vitro and in vivo. This study identified a critical role of α2,6-sialylation of SACC EVs in lung metastasis. The findings indicate that EV α2,6-sialylation-induced ER stress in endothelial cells might be a therapeutic target for preventing SACC lung metastasis.

Exosomal signaling in cancer metastasis: Molecular insights and therapeutic opportunities.

Exosomes are membrane-bound extracellular vesicles that play a role in exchanging biological products across membranes and serve as intermediaries in intercellular communication to maintain normal homeostasis. Numerous molecules, including lipids, proteins, and nucleic acids are enclosed in exosomes. Exosomes are constantly released into the extracellular environment and exhibit distinct characteristics based on the secreted cells that produce them. Exosome-mediated cell-to-cell communication has reportedly been shown to affect multiple cancer hallmarks, such as immune response modulation, pre-metastatic niche formation, angiogenesis, stromal cell reprogramming, extracellular matrix architecture remodeling, or even drug resistance, and eventually the development and metastasis of cancer cells. Exosomes can be used as therapeutic targets and possible diagnostic biomarkers by selectively loading oncogenic molecules into them. We highlight the important roles that exosomes play in cancer development in this review, which may lead to the development of fresh approaches for future clinical uses.

Circulating tumor cells shed large extracellular vesicles in capillary bifurcations that activate endothelial and immune cells.

Circulating tumor cells (CTCs) and their clusters are the drivers of metastasis, but we have an incomplete understanding of how they interact with capillary beds. Using microfluidic models mimicking human capillary bifurcations, we observed cell size- and bifurcation-dependent shedding of nuclei-free fragments by patient CTCs, CTC-derived explant cells and numerous cancer cell lines. Shedding reduced cell sizes up to 61%, facilitating their transit through bifurcations. We demonstrated that shed fragments were a novel subclass of large extracellular vesicles (LEVs), "shearosomes", that require shear stress for their biogenesis and whose proteome was associated with immune-related pathways. Shearosomes exhibited functions characteristic of previously identified EVs including cell-directed internalization by endothelial and immune cells, and intercellular communication abilities such as disruption of endothelial barrier integrity, polarization of monocytes into M2 tumor-promoting macrophages and interactions between endothelial and immune cells. Cumulatively, these findings suggest that CTCs shed shearosomes in capillary beds that drive key processes involved in the formation of pre-metastatic niches.

Macrophages promote pre-metastatic niche formation of breast cancer through aryl hydrocarbon receptor activity

Macrophages that acquire an immunosuppressive phenotype play a crucial role in establishing the pre-metastatic niche (PMN), which is essential for facilitating breast cancer metastasis to distant organs. Our study showed that increased activity of the aryl hydrocarbon receptor (AHR) in lung macrophages plays a crucial role in establishing the immunosuppressive PMN in breast cancer. Specifically, AHR activation led to high expression of PD-L1 on macrophages by directly binding to the promoter of Pdl1. This upregulation of PD-L1 promoted the differentiation of regulatory T cells (Tregs) within the PMN, further enhancing immunosuppressive conditions. Mice with Ahr conditional deletion in macrophages had reduced lung metastasis of breast cancer. The elevated AHR levels in PMN macrophages were induced by GM-CSF, which was secreted by breast cancer cells. Mechanistically, the activated STAT5 signaling pathway induced by GM-CSF prevented AHR from being ubiquitinated, thereby sustaining its activity in macrophages. In breast cancer patients, the expression of AHR and PD-L1 was correlated with increased Treg cell infiltration, and higher levels of AHR were associated with a poor prognosis. These findings reveal that the crosstalk of breast cancer cells, lung macrophages, and Treg cells via the GM-CSF-STAT5-AHR-PD-L1 cascade modulates the lung pre-metastatic niche during breast cancer progression.

C-Reactive Protein Facilitates Premetastatic Niche Formation in the Lungs.

C-reactive protein (CRP) has long been recognized as a marker of inflammation, but its evolving role in immunomodulation and cancer has increasingly been recognized. In recent years, multiple studies have explored CRP as a biomarker for prognosis and therapy response, particularly in the context of cancer immunotherapy. In this issue of Cancer Research, Feng and colleagues investigate the role of CRP in the development of lung metastasis. They provide evidence for a direct role of CRP acting together with commensal bacteria to instruct an immune-tolerant state of pulmonary macrophages through Fc gamma receptor IIb signaling. By suppressing immune surveillance in the lungs, CRP facilitates the formation of a premetastatic niche, allowing circulating tumor cells to establish metastases. See related article by Feng et al., p. 4184.

Breast cancer stem cell-derived exosomal lnc-PDGFD induces fibroblast-niche formation and promotes lung metastasis.

Triple-negative breast cancer (TNBC) is the most aggressive subtype with high metastatic potential and lack of therapeutic targets. Breast cancer stem cells (BCSCs) are enriched in TNBC and contribute to its metastatic propensity. Accumulating evidence suggests that cancer-derived exosomes are key drivers of premetastatic niche formation in distal organs. However, the function and underlying mechanism of BCSC-derived exosomes in TNBC metastasis remain elusive. Here, we demonstrated that BCSC-derived exosomes exhibit a greater capacity to activate fibroblasts and promote TNBC cell metastasis to the lung than non-BCSC-derived exosomes. Additionally, we found that upregulation of exosomal long non-coding RNA platelet derived growth factor D (lnc-PDGFD) expression in BCSCs is responsible for fibroblast activation through YBX1/NF-kB signaling in the lung. Activated fibroblasts further promote tumor progression by secreting IL-11. Taken together, BCSC-derived exosomes enriched with lnc-PDGFD could activate fibroblasts, thereby facilitating lung metastasis in TNBC patients. These results provide new insights into the mechanism of TNBC metastasis to the lung.

The Lymphatic Vascular System in Extracellular Vesicle-Mediated Tumor Progression.

Tumor growth and progression require molecular interactions between malignant and host cells. In recent years, extracellular vesicles (EVs) emerged as an important pillar of such interactions, carrying molecular information from their donor cells to distant recipient cells. Thereby, the phenotype and function of the recipient cells are altered, which may facilitate tumor immune escape and tumor metastasis to other organs through the formation of pre-metastatic niches. A prerequisite for these effects of tumor cell-derived EVs is an efficient transport system from the site of origin to the body periphery. Here, we highlight the role of the lymphatic vascular system in the distribution and progression-promoting functions of tumor cell-derived EVs. Importantly, the lymphatic vascular system is the primary drainage system for interstitial fluid and its soluble, particulate, and cellular contents, and therefore represents the principal route for regional (i.e., to tumor-draining lymph nodes) and systemic distribution of EVs derived from solid tumors. Furthermore, recent studies highlighted the tumor-draining lymph node as a crucial site where tumor-derived EVs exert their effects. A deeper mechanistic understanding of how EVs gain access to the lymphatic vasculature, how they interact with their recipient cells in tumor-draining lymph nodes and beyond, and how they induce phenotypic and functional maladaptation will be instrumental to identify new molecular targets and conceive innovative approaches for cancer therapy.

Tumor-derived exosomes: unravelling the pathogenesis of pancreatic cancer with liver metastases and exploring the potential for clinical translation.

Pancreatic cancer (PC) is one of the most malignant solid cancers, and PC metastasis, particularly liver metastasis, is a major cause of cancer mortality. A key event in tumor metastasis is the formation of pre-metastatic niche (PMN), which provides a microenvironment conducive to tumor cells colonization and progression. Various molecules loaded in tumor-derived exosomes (TDEs) contribute to PMN formation and distant tumor metastasis, by regulating immune and stromal cell function, inducing angiogenesis, and promoting metabolic reprogramming. Therefore, therapies targeting PMN may offer novel advantages to prevent tumor metastasis at an earlier stage. In this review, we summarize multifaceted mechanisms underlying hepatic PMN formation, with a focus on how PC TDEs participate in angiogenesis and vascular permeability, create immune suppressive microenvironment, remodel the extracellular matrix, and regulate metabolic reprogramming. In addition, we highlight the promise of TDEs for early diagnosis and effective therapy of PC liver metastases.

Tumor-derived EBV-miR-BART2-5p promotes nasopharyngeal carcinoma metastasis by inducing pre-metastatic endothelial cell pyroptosis.

Extravasation is a key step in tumor metastasis. Epstein‒Barr virus (EBV) plays a crucial role in nasopharyngeal carcinoma (NPC) metastasis. However, the functions and molecular mechanisms of EBV during tumor cell extravasation remains unclear. Here, we showed that the expression of pyroptosis-associated proteins is greater in the endothelial cells of metastatic NPC tissues than in those of nontumor tissues Exosomes derived from NPC cells promoted endothelial cell pyroptosis, vascular permeability, and tumor cell extravasation. Moreover, we found that BART2-5p is abundant in serum exosomes from NPC patients with metastasis and NPC cells, and that it regulates endothelial cell pyroptosis in pre-metastatic organs via MRE11A. Exosomes containing a BART2-5p inhibitor and AAV-MRE11A attenuated endothelial cell pyroptosis and tumor metastasis. Moreover, in the endothelial cells of metastatic tissues from NPC patients, the BART2-5p level was positively associated with pyroptosis-related protein expression. Collectively, our findings suggest that exosomal BART2-5p is involved in pre-metastatic niche formation, identifying secreted BART2-5p as a potential therapeutic target for NPC metastasis. Implications: The finding that secreted BART2-5p is involved in pre-metastatic niche formation may aid the development of potential therapeutic target for NPC metastasis.

A Multicellular Mechanochemical Model to Investigate Tumor Microenvironment Remodeling and Pre-Metastatic Niche Formation

A Multicellular Mechanochemical Model to Investigate Tumor Microenvironment Remodeling and Pre-Metastatic Niche Formation

LSD1 deficiency in breast cancer cells promotes the formation of pre-metastatic niches

Lysine-specific demethylase 1 (LSD1), a histone demethylating enzyme, plays a crucial role in cancer metastasis. Studies show LSD1 knockout promotes breast cancer lung metastasis, but it’s unknown if it alters the lung microenvironment for metastasis. In this study, we investigated the effects of exosomes from LSD1-knockdown (LSD1 KD) breast cancer cells on pre-metastatic niche formation. Injecting exosomes from LSD1 KD cells in mice resulted in a substantial increase in lung colonization by breast cancer cells, while treatment with exosomes derived from LSD1 KD cells decreased the expression of the ZO-1 and occludin, leading to increased vascular permeability. The LSD1 KD reduced the expression of circDOCK1, which augmented the levels of miR-1270 in exosomes. And miR-1270 inhibited ZO-1 expression in human endothelial cells, which enhanced their permeability. Our study uncovered a novel mechanism in which the LSD1 promotes the formation of pre-metastatic niches via the regulation of exosomal miRNA.

Targeting SPP1-orchestrated neutrophil extracellular traps-dominant pre-metastatic niche reduced HCC lung metastasis

BackgroundThe mechanisms by which tumor-derived factors remodel the microenvironment of target organs to facilitate cancer metastasis, especially organ-specific metastasis, remains obscure. Our previous studies have demonstrated that SPP1 plays a key role in promoting metastasis of hepatocellular carcinoma (HCC). However, the functional roles and mechanisms of tumor-derived SPP1 in shaping the pre-metastatic niche (PMN) and promoting lung-specific metastasis are unclear.MethodsOrthotopic metastasis models, experimental metastasis models, CyTOF and flow cytometry were conducted to explore the function of SPP1 in shaping neutrophil-dominant PMN and promoting HCC lung metastasis. The main source of CXCL1 in lung tissues was investigated via fluorescence activated cell sorting and immunofluorescence staining. The expression of neutrophils and neutrophil extracellular traps (NETs) markers was detected in the lung metastatic lesions of HCC patients and mouse lung specimens. The therapeutic significance was explored via in vivo DNase I and CXCR2 inhibitor assays.ResultsSPP1 promoted HCC lung colonization and metastasis by modifying pulmonary PMN in various murine models, and plasma SPP1 levels were closely associated with lung metastasis in HCC patients. Mechanistically, SPP1 binded to CD44 on lung alveolar epithelial cells to produce CXCL1, thereby attracting and forming neutrophil-abundant PMN in the lung. The recruited neutrophils were activated by SPP1 and then formed NETs-dominant PMN to trap the disseminated tumor cells and promote metastatic colonization. Moreover, early intervention of SPP1-orchestrated PMN by co-targeting the CXCL1-CXCR2 axis and NETs formation could efficiently inhibit the lung metastasis of HCC.ConclusionsOur study illustrates that HCC-lung host cell-neutrophil interactions play important roles in PMN formation and SPP1-induced HCC lung metastasis. Early intervention in SPP1-orchestrated PMN via CXCR2 inhibitor and DNase I is a potential therapeutic strategy to combat HCC lung metastasis.

Immunological Pre-Metastatic Niche in Dogs With Naturally Occurring Osteosarcoma.

Pre-metastatic niche (PMN) formation is essential for metastatic development and drives organotropism. Tumour-derived extracellular vesicles and soluble factors remodel the microenvironment of distant metastatic organs before subsequent metastasis. Dogs with osteosarcoma (OS) have proven to be excellent disease models for their human companions. Here, we show evidence of PMN formation in dogs with OS before metastasis. We necropsied and sampled lung tissues from dogs with naturally occurring treatment-naïve OS (n = 15) and control dogs without cancer (n = 10). We further divided dogs with OS into those having lung metastases (n = 5) and those without (n = 10). We stained formalin-fixed paraffin-embedded tissues using multiplex immunofluorescence to quantify the number of bone marrow-derived cells, monocytes and macrophages in the lung samples from each dog. The numbers of CD204+ macrophages, CD206+ macrophages and monocytes and CD11d+ bone marrow-derived cells (BMDCs) were significantly higher in the pre-metastatic lung of dogs with OS (n = 10) than in control dogs without cancer (n = 10). Furthermore, the total nucleated cell (DAPI+) density was higher before metastasis than in healthy lungs. In dogs with established metastases, the number of CD11d+ BMDCs was significantly lower than in the pre-metastatic lung, suggesting this recruitment is transient. Our study provides evidence of PMN existence in a naturally occurring cancer model similar to those observed in pre-clinical murine models. BMDCs are recruited to the lungs before metastases have developed. Dogs with OS may represent ideal candidates for assessing new PMN-targeting therapies.

Granulocyte-like myeloid-derived suppressor cells: The culprits of neutrophil extracellular traps formation in the pre-metastatic niche

Neutrophil extracellular traps (NETs) have been shown to exhibit chemotactic effects on circulating tumor cells at metastatic sites, promoting the progression of colorectal cancer liver metastasis (CRLM). However, the origin and factors contributing to the formation of NETs (NETosis) in the pre-metastatic niche (PMN) of target organs remain unclear. In this study, we investigated the relationship between phosphatase of regenerating liver-3 (PRL-3), myeloid-derived suppressor cells (MDSCs), neutrophils, and NETs through a retrospective clinical cohort study and a mouse model of CRLM. Our clinical findings revealed associations between PRL-3 expression and the infiltration of neutrophils and MDSCs in CRLM patients. Moreover, NETosis emerged as a robust indicator of poor prognosis for overall survival in these patients. In CRLM models, PRL-3 overexpression enhanced both primary tumor growth and liver metastasis. We found that the first week after tumor cell implantation appeared to be a crucial period for PMN formation, with notable infiltration of neutrophils, MDSCs, and NETosis during this time. Notably, co-culturing neutrophils with MDSCs induced NETosis in vitro, particularly with granulocyte-like MDSCs (Gr-MDSCs), the predominant subtype of infiltrating MDSCs. In summary, our findings elucidate the likely origin of NETs in the PMN during CRLM development and underscore the significant influence of PRL-3. These findings may offer potential immunotherapeutic targets for patients at risk of developing CRLM, warranting further investigation in clinical settings.

Ephrin A1 Stimulates CCL2 Secretion to Facilitate Premetastatic Niche Formation and Promote Gastric Cancer Liver Metastasis.

The liver is a primary target for distal metastasis of gastric cancer. The hepatic premetastatic niche (PMN) facilitates crucial communications between primary tumor and liver, thereby playing an essential role in hepatic metastasis. Identification of the molecular mechanisms driving PMN formation in gastric cancer could facilitate development of strategies to prevent and treat liver metastasis. Here, we uncovered a role for ephrin A1 (EFNA1) signaling in development of the PMN. EFNA1 overexpression in gastric cancer cells significantly increased C-C motif chemokine ligand 2 (CCL2) secretion through the Hippo-YAP pathway. Secreted CCL2 activated hepatic stellate cells (HStC) within the hepatic PMN via the WNT/β-catenin pathway. Inhibition of CCL2 significantly suppressed HStC activation and reduced liver metastasis triggered by EFNA1 signaling in gastric cancer cells. Moreover, high CCL2 expression correlated with poor survival in patients with cancer. Overall, these findings reveal that EFNA1 signaling in gastric cancer cells upregulates CCL2, which activates HStCs to engender establishment of a hepatic PMN that supports liver metastasis. Significance: Cross-talk between gastric cancer cells and hepatic stellate cells mediated by the EFNA1/CCL2 axis induces premetastatic niche development to facilitate metastatic spread, nominating CCL2 as a therapeutic target to suppress liver metastasis.

Integrin α6-containing extracellular vesicles promote lymphatic remodelling for pre-metastatic niche formation in lymph nodes via interplay with CD151.

Heterogeneous extracellular vesicles (EVs) from various types of tumours are acknowledged for inducing the formation of pre-metastatic "niches" in draining lymph nodes (LNs) to promote lymphatic metastasis. In order to identify the specific subpopulations of EVs involved, we performed high-resolution proteomic analysis combined with nanoflow cytometry of bladder cancer (BCa) tissue-derived EVs to identify a novel subset of tumour-derived EVs that contain integrin α6 (ITGA6+EVs) and revealed the positive correlation of ITGA6+EVs with the formation of pre-metastatic niche in draining LNs and lymphatic metastasis in multicentre clinical analysis of 820-case BCa patients. BCa-derived ITGA6+EVs induced E-selectin (SELE)-marked lymphatic remodelling pre-metastatic niche and promoted metastasis in draining LNs through delivering cargo circRNA-LIPAR to lymphatic endothelial cells in vivo and in vitro. Mechanistically, LIPAR linked ITGA6 to the switch II domain of RAB5A and sustained RAB5A GTP-bound activated state, thus maintaining the production of ITGA6+EVs loaded with LIPAR through endosomal trafficking. ITGA6+EVs targeted lymphatic vessels through ITGA6-CD151 interplay and released LIPAR to induce SELE overexpression-marked lymphatic remodelling pre-metastatic niche. Importantly, we constructed engineered-ITGA6 EVs to inhibit lymphatic pre-metastatic niche, which suppressed lymphatic metastasis and prolonged survival in preclinical models. Collectively, our study uncovers the mechanism of BCa-derived ITGA6+EVs mediating pre-metastatic niche and provides an engineered-EV-based strategy against BCa lymphatic metastasis.