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Background Excessive extracellular matrix deposition and increased stiffness are typical features of solid tumors such as hepatocellular carcinoma (HCC) and pancreatic ductal adenocarcinoma (PDAC). These conditions create confined spaces for tumor cell migration and metastasis. The regulatory mechanism of confined migration remains unclear. Methods LC–MS was applied to determine the differentially expressed proteins between HCC tissues and corresponding adjacent tissue. Collective migration and single cell migration microfluidic devices with 6 μm-high confined channels were designed and fabricated to mimic the in vivo confined space. 3D invasion assay was created by Matrigel and Collagen I mixture treat to adherent cells. 3D spheroid formation under various stiffness environment was developed by different substitution percentage GelMA. Immunoprecipitation was performed to pull down the LH1-binding proteins, which were identified by LC–MS. Immunofluorescent staining, FRET, RT-PCR, Western blotting, FRAP, CCK-8, transwell cell migration, wound healing, orthotopic liver injection mouse model and in vivo imaging were used to evaluate the target expression and cellular phenotype. Results Lysyl hydroxylase 1 (LH1) promoted the confined migration of cancer cells at both collective and single cell levels. In addition, LH1 enhanced cell invasion in a 3D biomimetic model and spheroid formation in stiffer environments. High LH1 expression correlated with poor prognosis of both HCC and PDAC patients, while it also promoted in vivo metastasis. Mechanistically, LH1 bound and stabilized Septin2 (SEPT2) to enhance actin polymerization, depending on the hydroxylase domain. Finally, the subpopulation with high expression of both LH1 and SEPT2 had the poorest prognosis. Conclusions LH1 promotes the confined migration and metastasis of cancer cells by stabilizing SEPT2 and thus facilitating actin polymerization.

Background: Acidic microenvironment is a common physiological phenomenon in tumors, and is closely related to cancer development, but the effects of acidosis on pancreatic adenocarcinoma (PDAC) remains to be elucidated. Methods : Metabonomic assay and transcriptomic microarray were used to detect the changes of metabolites and gene expression profile respectively in acidosis-adapted PDAC cells. Wound healing, transwell and in vivo assay were applied to evaluate cell migration and invasion capacity. CCK8 and colony formation assays were performed to determine cell proliferation. Results: The acidosis-adapted PDAC cells had stronger metastasis and proliferation ability compared with the control cells. Metabonomic analysis showed that acidosis-adapted PDAC cells had both increased glucose and decreased glycolysis, implying a shift to pentose phosphate pathway. The metabolic shift further led to the inactivation of AMPK by elevating ATP. Transcriptomic analysis revealed that the differentially expressed genes in acidosis-adapted cells were enriched in extracellular matrix modification and Hippo signaling. Besides, MMP1 was the most upregulated gene in acidosis-adapted cells, mediated by the YAP/TAZ pathway, but could be reduced by AMPK activator. Conclusion : The present study showed that metabolic reprogramming promotes proliferation and metastasis of acidosis-adapted PDAC cells by inhibiting AMPK/Hippo signaling, thus upregulating MMP1.

Cancer metastasis is the major cause of cancer‐related death. Excessive extracellular matrix deposition and increased stiffness are typical features of solid tumors, creating confined spaces for tumor cell migration and metastasis. Confined migration is involved in all metastasis steps. However, confined and unconfined migration inhibitors are different and drugs available to inhibit confined migration are rare. The main challenges are the modeling of confined migration, the suffering of low throughput, and others. Microfluidic device has the advantage to reduce reagent consumption and enhance throughput. Here, a microfluidic chip that can achieve multi‐function drug screening against the collective migration of cancer cells under confined environment is designed. This device is applied to screen out effective drugs on confined migration among a novel mechanoreceptors compound library (166 compounds) in hepatocellular carcinoma, non‐small lung cancer, breast cancer, and pancreatic ductal adenocarcinoma cells. Three compounds that can significantly inhibit confined migration in pan‐cancer: mitochonic acid 5 (MA‐5), SB‐705498, and diphenyleneiodonium chloride are found. Finally, it is elucidated that these drugs targeted mitochondria, actin polymerization, and cell viability, respectively. In sum, a high‐throughput microfluidic platform for screening drugs targeting confined migration is established and three novel inhibitors of confined migration in multiple cancer types are identified.