Neutrophil extracellular traps promote immune escape in hepatocellular carcinoma by up-regulating CD73 through Notch2.

Immune escape is the main reason that immunotherapy is ineffective in hepatocellular carcinoma (HCC). Here, this study illustrates a pathway mediated by neutrophil extracellular traps (NETs) that can promote immune escape of HCC. Mechanistically, we demonstrated that NETs up-regulated CD73 expression through activating Notch2 mediated nuclear factor kappa B (NF-κB) pathway, promoting regulatory T cells (Tregs) infiltration to mediate immune escape of HCC. In addition, we found the similar results in mouse HCC models by hydrodynamic plasmid transfection. The treatment of deoxyribonuclease I (DNase I) could inhibit the action of NETs and improve the therapeutic effect of anti-programmed cell death protein 1 (PD-1). In summary, our results revealed that targeting of NETs was a promising treatment to improve the therapeutic effect of anti-PD-1.

The scaffold of neutrophil extracellular traps promotes CCA progression and modulates angiogenesis via ITGAV/NFκB.

Neutrophil extracellular traps (NETs) have garnered attention for their dual role in host defense and tumor promotion. With their involvement documented across a spectrum of tumors, their influence on the progression of cholangiocarcinoma (CCA) is of paramount interest. We employed immunohistochemistry and immunofluorescence to detect NET deposition in CCA tissues. Through in vitro and in vivo investigation, including CCA organoid and transposon-based models in PAD4 KO mice, we explored the effects of NETs on cell proliferation and metastasis. Molecular insights were gained through RNA sequencing, enzyme linked immunosorbent assay, and chromatin immunoprecipitation. Elevated intratumoral NET deposition within CCA tissues was associated with poor survival. The influence of NETs on CCA proliferation, migration and invasion was primarily mediated by NET-DNA. RNA sequencing unveiled the activation of the NFκB signaling pathway due to NET-DNA stimulation. NET-DNA pull-down assay coupled with mass spectrometry revealed the interaction between NET-DNA and αV integrin (ITGAV), culmination in the activation of the NFκB pathway. Furthermore, NET-DNA directly upregulated the expression of VEGF-A in cancer cells. The study unequivocally establishes NETs as facilitators of CCA progression, orchestrating proliferation, metastasis, and angiogenesis through ITGAV/NFκB pathway activation. This novel insight positions NETs as prospective therapeutic targets for managing CCA patients. By implementing a variety of methodologies and drawing intricate connections between NETs, DNA interactions, and signaling pathways, this research expands our comprehension of the complex interplay between the immune system and cancer progression, offering promising avenues for intervention.

Downregulated Acetyl-CoA Acyltransferase 2 Promoted the Progression of Hepatocellular Carcinoma and Participated in the Formation of Immunosuppressive Microenvironment.

Background: The aim of this study is to explore the role of acetyl-CoA acyltransferase 2 (ACAA2) in the progression of hepatocellular carcinoma (HCC). Methods: Bulk RNA data and single-cell RNA data were acquired from The Cancer Genome Atlas and Gene Expression Omnibus. Both in vitro and in vivo studies were used to determine the effect of ACAA2 on the progression of HCC, and RNA sequencing analysis was performed to explore the mechanism. Results: We found downregulation of ACAA2 was involved in the malignant progression of HCC. The patient with low ACAA2 level had an immunosuppressive microenvironment in the HCC and predicted to have a poor prognosis. Decreased ACAA2 facilitated HCC proliferation and metastasis by activating the nuclear factor-κB (NFκB) signaling pathway. And increased CXCL1 induced by NFκB signaling pathway might be responsible for low level of ACAA2 related immunosuppressive microenvironment. Furthermore, the expression of ACAA2 was also detected in immune cells. The expression of ACAA2 in CD4+TCF7+T, CD4+FOXP3+T, CD8+GZMK+T, and CD8+KLRD1+T cells was inversely correlated with the composition of CD8+PDCD1+T cells in HCC. This effect might be due to the CCL5-CCRs and HLA-E-KLRCs ligand-receptor networks. Conclusion: In a conclusion, downregulated ACAA2 promoted the progression of hepatocellular carcinoma and might be participated in the formation of immunosuppressive microenvironment. ACAA2 could be served as a favorable indicator for the prognosis of HCC and an ideal biomarker for immunotherapy.

Targeting uridine-cytidine kinase 2 induced cell cycle arrest through dual mechanism and could improve the immune response of hepatocellular carcinoma.

BACKGROUND: Pyrimidine metabolism is critical for tumour progression. Uridine-cytidine kinase 2 (UCK2), a key regulator of pyrimidine metabolism, is elevated during hepatocellular carcinoma (HCC) development and exhibits carcinogenic effects. However, the key mechanism of UCK2 promoting HCC and the therapeutic value of UCK2 are still undefined. The aim of this study is to investigate the potential of UCK2 as a therapeutic target for HCC. METHODS: Gene expression matrices were obtained from public databases. RNA-seq, co-immunoprecipitation and RNA-binding protein immunoprecipitation were used to determine the mechanism of UCK2 promoting HCC. Immune cell infiltration level and immune-related functional scores were evaluated to assess the link between tumour microenvironment and UCK2. RESULTS: In HCC, the expression of UCK2 was upregulated in part by TGFß1 stimulation. UCK2 promoted cell cycle progression of HCC by preventing the degradation of mTOR protein and maintaining the stability of PDPK1 mRNA. We also identified UCK2 as a novel RNA-binding protein. Downregulation of UCK2 induced cell cycle arrest and activated the TNFα/NFκB signalling pathway-related senescence-associated secretory phenotype to modify the tumour microenvironment. Additionally, UCK2 was a biomarker of the immunosuppressive microenvironment. Downregulated UCK2 induced a secretory phenotype, which could improve the microenvironment, and decreased UCK2 remodelling metabolism could lower the resistance of tumour cells to T-cell-mediated killing. CONCLUSIONS: Targeting UCK2 inhibits HCC progression and could improve the response to immunotherapy in patients with HCC. Our study suggests that UCK2 could be an ideal target for HCC.

Exploring the role of mast cells in the progression of liver disease.

In addition to being associated with allergic diseases, parasites, bacteria, and venoms, a growing body of research indicates that mast cells and their mediators can regulate liver disease progression. When mast cells are activated, they degranulate and release many mediators, such as histamine, tryptase, chymase, transforming growth factor-ß1 (TGF-ß1), tumor necrosis factor-α(TNF-α), interleukins cytokines, and other substances that mediate the progression of liver disease. This article reviews the role of mast cells and their secretory mediators in developing hepatitis, cirrhosis and hepatocellular carcinoma (HCC) and their essential role in immunotherapy. Targeting MC infiltration may be a novel therapeutic option for improving liver disease progression.

Cytochrome B5 type A alleviates HCC metastasis via regulating STOML2 related autophagy and promoting sensitivity to ruxolitinib.

The incidence of hepatocellular carcinoma (HCC) is increasing in the world. However, its role and underlying molecular mechanism in HCC progression remain unclear. We found that CYB5A plays a key role in HCC metastasis by inhibiting the JAK1/STAT3 pathway through binding to STOML2. CYB5A combined with STOML2 can predict the outcome of patients. To demonstrate the effect of CYB5A on JAK1 inhibitor function, we applied Ruxolitinib in metastatic tumors with high CYB5A expression and found that it slowed disease progression and prolonged survival in mice. To the best of our knowledge, this study is the first to report the Ruxolitinib effect on the metastatic ability of HCC cells in vivo and in vitro.

A PLCB1-PI3K-AKT Signaling Axis Activates EMT to Promote Cholangiocarcinoma Progression.

As a member of the phospholipase family, phospholipase C beta 1 (PLCB1) is involved in phospholipid hydrolysis and is frequently upregulated in human cancer. However, little is known about the role of PLCB1 in cholangiocarcinoma (CCA). In this study, we uncover a role for PLCB1 in CCA progression and identify the underlying mechanisms. Both human CCA tissues and CCA cell lines expressed high levels of PLCB1. PLCB1 promoted tumor development and growth in various CCA mouse models, including transposon-based tumorigenesis models. PLCB1 activated PI3K/AKT signaling to induce CCA cells to undergo epithelial-to-mesenchymal transition (EMT). Mechanistically, PABPC1 interacted with PLCB1 and PI3K to amplify PLCB1-mediated EMT via PI3K/AKT/GSK3ß/Snail signaling. Ectopic PLCB1 induced resistance to treatment with gemcitabine combined with cisplatin, which could be reversed by the AKT inhibitor MK2206. PLCB1 expression was regulated by miR-26b-5p through direct interaction with PLCB1 3'UTR. Collectively, these data identify a PLCB1-PI3K-AKT signaling axis vital for CCA development and EMT, suggesting that AKT can be used as a therapeutic target to overcome chemotherapy resistance in CCA patients with high PLCB1 expression. SIGNIFICANCE: PLCB1 functions as an oncogenic driver in cholangiocarcinoma development that confers an actionable therapeutic vulnerability to AKT inhibition.

LncRNA coordinates Hippo and mTORC1 pathway activation in cancer.

The Hippo and mammalian target of rapamycin complex 1 (mTORC1) pathways are the two predominant pathways that regulate tumour growth and metastasis. Therefore, we explored the potential crosstalk between these two functionally relevant pathways to coordinate their tumour growth-control functions. We found that a Hippo pathway-related long noncoding RNA, HPR, directly interacts with Raptor, an essential component of mTORC1, to upregulate mTORC1 activation by impairing the phosphorylation of Raptor by AMPK. Knockdown or knockout of HPR in breast cancer and cholangiocarcinoma cells led to a reduction in tumour growth. Compared with HPR WT cells, HPR-overexpressing cells exhibited nuclear accumulation of YAP1, and significantly blocked the downregulation of mTORC1 signalling induced by energy stress. Thus, our study reveals a direct link between the Hippo and mTORC1 pathways in the control of tumour growth.

Inhibition of TGFß1 accelerates regeneration of fibrotic rat liver elicited by a novel two-staged hepatectomy.

Aims: Emerging evidence is demonstrating that rapid regeneration of remnant liver elicited by associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) may be attenuated in fibrotic livers. However, the molecular mechanisms responsible for this process are largely unknown. It is widely acknowledged that the TGFß1 signaling axis plays a major role in liver fibrosis. Therefore, the aims of this study were to elucidate the underlying mechanism of liver regeneration during ALPPS with or without fibrosis, specifically focusing on TGFß1 signaling. Approach: ALPPS was performed in rat models with N-diethylnitrosamine-induced liver fibrosis and no fibrosis. Functional liver remnant regeneration and expression of TGFß1 were analyzed during the ALPPS procedures. Adeno-associated virus-shTGFß1 and the small molecule inhibitor LY2157299 (galunisertib) were used separately or in combination to inhibit TGFß1 signaling in fibrotic rats. Results: Liver regeneration following ALPPS was lower in fibrotic rats than non-fibrotic rats. TGFß1 was a key mediator of postoperative regeneration in fibrotic liver. Interestingly, AAV-shTGFß1 accelerated the regeneration of fibrotic functional liver remnant and improved fibrosis, while LY2157299 only enhanced liver regeneration. Moreover, combination treatment elicited a stronger effect. Conclusions: Inhibition of TGFß1 accelerated regeneration of fibrotic liver, ameliorated liver fibrosis, and improved liver function following ALPPS. Therefore, TGFß1 is a promising therapeutic target in ALPPS to improve fibrotic liver reserve function and prognosis.

Downregulation of MARC2 Promotes Immune Escape and Is Associated With Immunosuppression of Hepatocellular Carcinoma.

The N-reductive enzyme system (NRES), composed of MARC1, MARC2, CYB5, and CYB5R, is responsible for the reduction of N-oxygenated compounds and participates in several physiological processes. For example, MARC2 serves as an important prognostic indicator and is downregulated in hepatocellular carcinoma, and the downregulation of MARC2 is critical to the regulation of lipid metabolism and cell cycle progression. However, the role of MARC2 in tumor immune microenvironment modification had not previously been investigated. In this study, we found that downregulation of MARC2 was associated with the differentiation of CD4+T cells into regulatory T cells (Tregs). Furthermore, restoring the expression of MARC2 could increase the expression of HLA-C and B2M via PPARA-related lipid metabolism signaling pathways, which could facilitate tumor antigen presentation to the tumor-infiltrating T cells. Additionally, MARC2 expression negatively correlated with several immune checkpoints. The immune checkpoint burden was generated based on 28 MARC2-related immune checkpoints. Patients with a higher immune checkpoint burden were predicted to have a poorer prognosis and a lower level of activated CD8+ T cells. The results showed that expression of the NRES is a prognostic indicator of hepatocellular carcinoma and MARC2 contributes significantly to predict the prognosis. Finally, loss of MARC2 in HCC patients was found to facilitate immune escape and was associated with immunosuppression.