Establishment of homotrimer collagen type I signature and its association with clinical manifestation and tertiary lymphoid structures formation in liver cancer.

Background: collagen type I is a fundamental composition of extracellular matrix. Typically it exists in the form of a heterotrimer, consisting of two α1 chains encoded by COL1A1 and one α2 chain encoded by COL1A2. However, in cancer a homotrimeric form of collagen type I comprises three α1 chains encoded by COL1A1 was founded. There is still a lack of transcriptional and histologic methods for detecting homotrimeric collagen type I. Furthermore, a comprehensive analysis of the pan-cancer distribution pattern and clinical relevance of homotrimeric collagen type I is conspicuously absent. Method: Using transcriptional and immunoflourance method, we established homocol signature, which is able to transcriptionally and histologically detect homotrimeric collagen type I. We investigated the diagnostic and prognostic potential of homocol as a novel cancer biomarker in a pan-cancer cohort. Furthermore, we assessed its association with clinical manifestations in a liver cancer cohort undergoing treatment at our institute. Result: Homotrimer Collagen Type I is predominantly expressed by cancer cells and is linked to several critical cancer hallmarks, particularly inflammatory response and proliferation. Survival analyses have indicated that a high Homocol expression is correlated with poor outcomes in most types of cancer studied. In terms of cancer detection, Homocol demonstrated strong performance in Receiver Operating Characteristic (ROC) analysis, with an Area Under Curve (AUC) of 0.83 for pan-cancer detection and between 0.72 and 0.99 for individual cancers.In cohorts undergoing PD1 treatment, we noted a higher presence of Homocol in the response group. In a Hepatocellular Carcinoma (HCC) clinical set, high Homocol expression was associated with an increased formation of intra-tumor tertiary lymphoid structures (TLS), larger tumor sizes, more advanced Barcelona Clinic Liver Cancer (BCLC) stages, higher microvascular invasion (MVI) grades, absence of a capsule, and an enriched para-tumor collagen presence. Conclusion: our research has led to the development of a novel gene signature that facilitates the detection of Homotrimer Collagen Type I. This may greatly assist efforts in cancer detection, prognosis, treatment response prediction, and further research into Homotrimer Collagen Type I.

Cirrhotic-extracellular matrix attenuates aPD-1 treatment response by initiating immunosuppressive neutrophil extracellular traps formation in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is closely associatedwith chronic liver diseases, particularly liver cirrhosis, which has an altered extracellular matrix (ECM) composition. The influence and its mechanism of the cirrhotic-ECM on the response of HCC to immune checkpoint inhibitor (ICI) remains less clarified. METHODS: In silico, proteomic and pathological assessment of alteration of cirrhotic-ECM were applied in clinical cohort. Multiple pre-clinical models with ECM manipulation were used to evaluate cirrhotic-ECM's effect on ICI treatment. In silico, flow cytometry and IHC were applied to explore how cirrhotic-ECM affect HCC microenvironment. In vitro and in vivo experiments were carried out to identify the mechanism of how cirrhotic-ECM undermined ICI treatment. RESULTS: We defined "a pro-tumor cirrhotic-ECM" which was featured as the up-regulation of collagen type 1 (Col1). Cirrhotic-ECM/Col1 was closely related to impaired T cell function and limited anti PD-1 (aPD-1) response of HCC patients from the TCGA pan cancer cohort and the authors' institution, as well as in multiple pre-clinical models. Mechanically, cirrhotic-ECM/Col1 orchestrated an immunosuppressive microenvironment (TME) by triggering Col1-DDR1-NFκB-CXCL8 axis, which initiated neutrophil extracellular traps (NETs) formation to shield HCC cells from attacking T cells and impede approaching T cells. Nilotinib, an inhibitor of DDR1, reversed the neutrophils/NETs dominant TME and efficiently enhanced the response of HCC to aPD-1. CONCLUSIONS: Cirrhotic-ECM modulated a NETs enriched TME in HCC, produced an immune suppressive TME and weakened ICI efficiency. Col1 receptor DDR1 could be a potential target synergically used with ICI to overcome ECM mediated ICI resistance. These provide a mechanical insight and novel strategy to overcome the ICI resistance of HCC.

Pan-Cancer Analysis Reveals a Distinct Neutrophil Extracellular Trap-Associated Regulatory Pattern.

Background: Neutrophils form extracellular net-like structures called neutrophil extracellular traps (NETs). Emerging evidence has shown that cancer can induce NET formation; however, it is not fully understood how NETs influence cancer biology, and no consensus has been reached on their pro- or antitumor effects. A comprehensive analysis of the global NET-associated gene regulatory network is currently unavailable and is urgently needed. Methods: We systematically explored and discussed NET enrichment, NET-associated gene regulatory patterns, and the prognostic implications of NETs in approximately 8,000 patients across 22 major human cancer types. We identified NET-associated regulatory gene sets that we then screened for NET-associated regulatory patterns that might affect patient survival. We functionally annotated the NET-associated regulatory patterns to compare the biological differences between NET-related survival subgroups. Results: A gene set variation analysis (GSVA) based on 23 major component genes was used to calculate a metric called the NET score. We found that the NET score was closely associated with many important cancer hallmarks, particularly inflammatory responses and epithelial-to-mesenchymal transition (EMT)-induced metastasis. Higher NET scores were related to poor immunotherapy response. Survival analysis revealed that NETs had diverse prognostic impacts among various cancer types. The NET-associated regulatory patterns linked to shorter or longer cancer patient survival were distinct from each other. Functional analysis revealed that more of the NET-associated regulatory genes linked to poor cancer survival were associated with extracellular matrix (ECM) remodeling and pan-cancerous risk factors. SPP1 was found to be highly expressed and correlated with NET formation in cancers with poor survival. We also found that the co-upregulation of NET formation and SPP1 expression was closely linked to increased EMT and poor survival, that SPP1 influenced NET-induced malignant capacity, and that SPP1 overproduction induced a robust formation of metastatic-promoting NETs. Conclusion: NETs were common across cancers but displayed a diverse regulatory pattern and outcome readouts in different cancer types. SPP1 is potentially the key to NET-related poor outcomes.

Neutrophil extracellular traps in hepatocellular carcinoma are enriched in oxidized mitochondrial DNA which is highly pro-inflammatory and pro-metastatic.

Background: Neutrophil extracellular traps (NETs) are net like extracellular structure formed by neutrophils in response to certain stimulation. It works as inflammatory regulator and metastasis promoter in cancer. Mitochondrial-(mt)DNA is a circular, mitochondria derived double strain molecule, which is involved in NETs formation. Its role in NETs induced inflammatory alteration in hepatocellular carcinoma (HCC) remained unexplored. Method: We evaluated the mitochondrial reactive oxygen species (mitoROS) level in peripheral neutrophils from HCC patients and the oxidative level of mtDNA in derived NETs. The association between the NETs and oxidized mtDNA was assessed to reveal their relevance. A function assay was applied to uncover how the oxidation state of mtDNA directed the metastasis promoting inflammation state in HCC cells in a NETs protein dependent manner. Finally, using animal models, we explored the potential of a therapy strategy against NETs-drove metastasis by targeting the oxidized mtDNA with metformin. Results: Neutrophils in HCC patients contained high level of mitoROS level, and formed NETs that were enriched in oxidized mtDNA in a mitoROS dependent manner. NETs and oxidized mtDNA were clinically relevant. Bound with NETs protein, oxidized mtDNA is more capable of triggering the metastasis-promoting inflammatory mediators in HepG2 cells. Targeting the oxidized mtDNA with metformin attenuated the metastasis-promoting inflammatory state and hereby undermine the metastasis capacity of HCC. Conclusion: HCC is capable to stimulate NETs enriched in oxidized mtDNA, which are highly pro-inflammatory and pro-metastatic. Oxidized mtDNA in NETs may serve as a potential anti-metastatic target by metformin therapy.

PKM2 Drives Hepatocellular Carcinoma Progression by Inducing Immunosuppressive Microenvironment.

Background and Aims: Pyruvate kinase M2 (PKM2) is an essential regulator of the Warburg effect, but its biological function promoting immune escape of hepatocellular carcinoma (HCC) is unclear. Methods: GEPIA web tool and immunohistochemistry (IHC) analysis were employed to evaluate the clinical relevance of PKM2 in HCC patients. Both in vitro CCK-8, colony formation, and transwell assays, and in vivo xenografts were performed to evaluate the malignancy of HCC cells. PKM2 and PD-L1 levels were examined by Western blot, qRT-PCR, and IHC. The role of PKM2 on in vivo immune response was also investigated. Results: PKM2 was significantly upregulated in HCC and associated with a poor prognosis of HCC patients. Knockdown of PKM2 inhibited in vitro proliferation, migration, and invasion of HCC cells, as well as in vivo tumor growth. Strikingly, PKM2 showed a strong correlation with the expression of immune inhibitory cytokines and lymphocyte infiltration in HCC. The overexpression of PKM2 sensitized HCC to immune checkpoint blockade, which enhanced IFN-γ positive CD8 T cells in HCC mice models. Conclusion: PKM2 might be a predictor and a potential therapeutic target for immune checkpoint inhibitors in HCC.

Isolation and characterization of exosomes for cancer research.

Exosomes are a subset of extracellular vesicles that carry specific combinations of proteins, nucleic acids, metabolites, and lipids. Mounting evidence suggests that exosomes participate in intercellular communication and act as important molecular vehicles in the regulation of numerous physiological and pathological processes, including cancer development. Exosomes are released by various cell types under both normal and pathological conditions, and they can be found in multiple bodily fluids. Moreover, exosomes carrying a wide variety of important macromolecules provide a window into altered cellular or tissue states. Their presence in biological fluids renders them an attractive, minimally invasive approach for liquid biopsies with potential biomarkers for cancer diagnosis, prediction, and surveillance. Due to their biocompatibility and low immunogenicity and cytotoxicity, exosomes have potential clinical applications in the development of innovative therapeutic approaches. Here, we summarize recent advances in various technologies for exosome isolation for cancer research. We outline the functions of exosomes in regulating tumor metastasis, drug resistance, and immune modulation in the context of cancer development. Finally, we discuss prospects and challenges for the clinical development of exosome-based liquid biopsies and therapeutics.