Targeting neuropilin-1 abolishes anti-PD-1-upregulated regulatory T cells and synergizes with 4-1BB agonist for liver cancer treatment.

BACKGROUND AIMS: Regulatory T cells (Tregs) are an obstacle to PD-1 blockade-mediated antitumor efficacy. However, the behaviors of Tregs response to anti-PD-1 in HCC and the characteristics of Tregs tissue adaptation from peripheral lymphoid tissues to the tumor are still unclear. APPROACH RESULTS: Here, we determine that PD-1 monotherapy potentially augments the accumulation of tumor CD4 + Tregs. Mechanistically, anti-PD-1 mediates Tregs proliferation in lymphoid tissues rather than in the tumor. Increased peripheral Tregs burden replenishes intratumoral Tregs, raising the ratio of intratumoral CD4 + Tregs to CD8 + T cells. Subsequently, single-cell transcriptomics revealed that neuropilin-1 (Nrp-1) supports Tregs migration behavior, and the genes of Crem and Tnfrsf9 regulate the behaviors of the terminal suppressive Tregs. Nrp-1 + 4-1BB - Tregs stepwise develop to the Nrp-1 - 4-1BB + Tregs from lymphoid tissues into the tumor. Moreover, Treg-restricted Nrp1 depletion abolishes anti-PD-1-upregulated intratumoral Tregs burden and synergizes with the 4-1BB agonist to enhance the antitumor response. Finally, a combination of the Nrp-1 inhibitor and the 4-1BB agonist in humanized HCC models showed a favorable and safe outcome and evoked the antitumor effect of the PD-1 blockade. CONCLUSION: Our findings elucidate the potential mechanism of anti-PD-1-mediated intratumoral Tregs accumulation in HCC and uncover the tissue adaptation characteristics of Tregs and identify the therapeutic potential of targeting Nrp-1 and 4-1BB for reprogramming the HCC microenvironment.

Lenvatinib enhances antitumor immunity by promoting the infiltration of TCF1+ CD8+ T cells in HCC via blocking VEGFR2.

Lenvatinib is the favorable treatment for advanced hepatocellular carcinoma (HCC), and it is currently undergoing phase III clinical trials. However, the specific effects of lenvatinib on PD1+ CD8+ T cells in HCC microenvironment have not been systematically studied. Here, we established an orthotopic hepa1-6 mouse model treated with lenvatinib to investigate CD8+ T cells' role in the tumor and spleen. We found an increasing proportion of TCF-1+ in PD1+ CD8+ T cells and proliferation of PD1+ CD8+ T cells after lenvatinib treatment. Meanwhile, lenvatinib treatment upregulated the expression of granzyme B on PD1+ CD8+ T cells both in vitro and in vivo. Lenvatinib activated the endogenous mTOR pathway of exhausted CD8+ T cells, and mTOR pathway blockade eliminated the antitumor effect of lenvatinib and function of PD1+ CD8+ T cells. The effects of the mTOR pathway on PD1+ CD8+ T cells after lenvatinib treatment were mediated by VEGFR2 inhibition. Overall, our work provides insight into the mechanism of lenvatinib's antitumor efficacy through exhausted CD8+ T cells in HCC treatment.

Blocking CD47 promotes antitumour immunity through CD103+ dendritic cell-NK cell axis in murine hepatocellular carcinoma model.

BACKGROUND & AIMS: The CD47-signal regulatory protein α (SIRPα) axis inhibits dendritic cell (DC) phagocytosis and contributes to immune evasion. However, the behaviour of DCs and the potential crosstalk between DCs and natural killer (NK) cells in the hepatocellular carcinoma (HCC) microenvironment after CD47 blockade remain unclear. METHODS: The infiltration of CD103+ DCs and NK cells were analysed by immunohistochemistry and immunofluorescence in both human and murine HCC specimens. An orthotopic liver tumour model was used to evaluate the function of the CD103+ DC-NK cell axis after CD47 blockade in vivo in wild-type, Rag1-/-, Batf3-/-, and STING1-/- mice. Phagocytosis assays were performed in CD103+ DC and HCC cell lines. CD103+ DC-derived cytokines were analysed by chemokine array. Spleen-derived NK cells in C57BL/6J mice were used to evaluate cytotoxic functions in vitro. RESULTS: Higher CD47 expression was associated with worse prognosis in patients with HCC. CD47 blockade enhanced antitumour efficacy by stimulating the CD103+ DC-NK cell axis. The hypoxic microenvironment promoted CD47 blockade-induced tumour DNA phagocytosis by CD103+ DCs. By releasing IL-12 and CXCL9, activated CD103+ DCs induced the recruitment of NK cells with upregulated expression of granzyme B, NKG2D, interferon-γ, and tumour necrosis factor-α and downregulated expression of NKG2A. The antitumour effects of CD47 blockade could be abolished by cyclic GMP-AMP synthase (cGAS)-STING pathway inhibition. CONCLUSIONS: In addition to the classical DC-T cell axis, CD47 blockade significantly enhanced the ability of CD103+ DCs to take up tumour DNA, resulting in the stimulation of the cGAS-STING pathway, which promoted the infiltration and activation of NK cells in liver cancer. LAY SUMMARY: Hypoxia (low oxygen levels) is prevalent in the hepatocellular carcinoma microenvironment and promotes the phagocytosis (ingestion and elimination) of tumour DNA by CD103+ dendritic cells (a type of immune cell). Blockade of the cell surface protein CD47 resulted in activation of CD103+ dendritic cells which led to the recruitment and activation of natural killer cells (a different immune cell). When activated, these cells exhibit an antitumour effect.

Blocking Triggering Receptor Expressed on Myeloid Cells-1-Positive Tumor-Associated Macrophages Induced by Hypoxia Reverses Immunosuppression and Anti-Programmed Cell Death Ligand 1 Resistance in Liver Cancer.

Tumor-associated macrophages (TAMs) are recognized as antitumor suppressors, but how TAMs behave in the hypoxic environment of hepatocellular carcinoma (HCC) remains unclear. Here, we demonstrated that hypoxia inducible factor 1α induced increased expression of triggering receptor expressed on myeloid cells-1 (TREM-1) in TAMs, resulting in immunosuppression. Specifically, TREM-1-positive (TREM-1+ ) TAMs abundant at advanced stages of HCC progression indirectly impaired the cytotoxic functions of CD8+ T cells and induced CD8+ T-cells apoptosis. Biological and functional assays showed that TREM-1+ TAMs had higher expression of programmed cell death ligand 1 (PD-L1) under hypoxic environment. However, TREM-1+ TAMs could abrogate spontaneous and PD-L1-blockade-mediated antitumor effects in vivo, suggesting that TREM-1+ TAM-induced immunosuppression was dependent on a pathway separate from PD-L1/programmed cell death 1 axis. Moreover, TREM-1+ TAM-associated regulatory T cells (Tregs) were crucial for HCC resistance to anti-PD-L1 therapy. Mechanistically, TREM-1+ TAMs elevated chemokine (C-C motif) ligand 20 expression through the extracellular signal-regulated kinase/NF-κß pathway in response to hypoxia and tumor metabolites leading to CCR6+ Foxp3+ Treg accumulation. Blocking the TREM-1 pathway could significantly inhibit tumor progression, reduce CCR6+ Foxp3+ Treg recruitment, and improve the therapeutic efficacy of PD-L1 blockade. Thus, these data demonstrated that CCR6+ Foxp3+ Treg recruitment was crucial for TREM-1+ TAM-mediated anti-PD-L1 resistance and immunosuppression in hypoxic tumor environment. Conclusion: This study highlighted that the hypoxic environment initiated the onset of tumor immunosuppression through TREM-1+ TAMs attracting CCR6+ Foxp3+ Tregs, and TREM-1+ TAMs endowed HCC with anti-PD-L1 therapy resistance.

YAP promotes multi-drug resistance and inhibits autophagy-related cell death in hepatocellular carcinoma via the RAC1-ROS-mTOR pathway.

BACKGROUND: Multi-drug resistance is the major cause of chemotherapy failure in hepatocellular carcinoma (HCC). YAP, a critical effector of the Hippo pathway, has been shown to contribute to the progression, metastasis and invasion of cancers. However, the potential role of YAP in mediating drug resistance remains obscure. METHODS: RT-qPCR and western blot were used to assess YAP expression in HCC cell lines. CCK-8 assays, flow cytometry, a xenograft tumour model, immunochemistry and GFP-mRFP-LC3 fusion proteins were utilized to evaluate the effect of YAP on multi-drug resistance, intracellular ROS production and the autophagy of HCC cells in vitro and in vivo. Autophagy inhibitor and rescue experiments were carried out to elucidate the mechanism by which YAP promotes chemoresistance in HCC cells. RESULTS: We found that BEL/FU, a typical HCC cell line with chemoresistance, exhibited overexpression of YAP. Moreover, the inhibition of YAP by shRNA or verteporfin conferred the sensitivity of BEL/FU cells to chemotherapeutic agents through autophagy-related cell death in vitro and in vivo. Mechanistically, YAP silencing significantly enhanced autophagic flux by increasing RAC1-driven ROS, which contributed to the inactivation of mTOR in HCC cells. In addition, the antagonist of autophagy reversed the enhanced effect of YAP silencing on cell death under treatment with chemotherapeutic agents. CONCLUSION: Our findings suggested that YAP upregulation endowed HCC cells with multi-drug resistance via the RAC1-ROS-mTOR pathway, resulting in the repression of autophagy-related cell death. The blockade of YAP may serve as a promising novel therapeutic strategy for overcoming chemoresistance in HCC.

Dual-function of Baicalin in nsPEFs-treated Hepatocytes and Hepatocellular Carcinoma cells for Different Death Pathway and Mitochondrial Response.

Nanosecond pulsed electric fields (nsPEFs) is emerged as a potential curative modality to ablate hepatocellular carcinoma (HCC). The application of local ablation is usually limited by insufficiency of liver function. While baicalin, a flavonoid isolated from Scutellaria baicalensis Georgi, has been proven to possess both anti-tumor and protective effects. Our study aimed to estimate different responses of hepatic cancer cells and hepatocytes to the combination of nsPEFs and baicalin. Cell viability, apoptosis and necrosis, mitochondrial transmembrane potential (MTP) and reactive oxygen species (ROS) were examined by CCK-8, FCM, JC-1 and fluorescent probe, respectively. After treatment by nsPEFs, most hepatocytes died by apoptosis, nevertheless, nearly all cancer cells were killed through necrosis. Low concentration of baicalin synergically enhanced nsPEFs-induced suppression and necrosis of HCC cells, nevertheless, the application of baicalin protected normal hepatocytes from the injury caused by nsPEFs, owing to elevating mitochondrial transmembrane potential and reducing ROS generation. Our work provided an advantageous therapy for HCC through the enhanced combination treatment of nsPEFs and baicalin, with which could improve the tumor-ablation effect and alleviate the injury of hepatic tissues simultaneously.

Blocking MARCO+ tumor-associated macrophages improves anti-PD-L1 therapy of hepatocellular carcinoma by promoting the activation of STING-IFN type I pathway.

The PD-L1/PD-1 axis is a classic immunotherapy target. However, anti-PD-L1/PD-1 therapy alone can not achieve satisfactory results in solid tumors, especially liver cancer. Among the several factors involved in tumor anti-PD-L1/PD-1 treatment resistance, tumor-associated macrophages (TAMs) have attracted attention because of their immunosuppressive ability. TAMs with a macrophage receptor with a collagenous structure (MARCO) are a macrophage subset group with strong immunosuppressive abilities. Clinical specimens and animal experiments revealed a negative correlation between MARCO + TAMs and patient prognosis with liver cancer. Transcriptional data and in vitro and in vivo experiments revealed that MARCO + TAM immunosuppressive ability was related to secretion. MARCO suppressed IFN-ß secretion from TAMs, reducing antigen presentation molecule expression, infiltration, and CD8+T cell dysfunction, thus producing an immunosuppressive microenvironment in liver cancer. MARCO can promote dying tumor cell clearance by macrophages, reducing tumor-derived cGAMP and ATP accumulation in the tumor microenvironment and inhibiting sting-IFN-ß pathway activation mediated by P2X7R in MARCO+TAMs. Animal experiments revealed that the MARCO and PD-L1 monoclonal antibody combination could significantly inhibit liver cancer growth. Conclusively, targeting MARCO+TAMs can significantly improve anti-PD-L1 resistance in liver cancer, making it a potential novel immune target for liver cancer therapy.

Correction: Ding et al. Full-Right Full-Left Split Liver Transplantation for Two Adult Recipients: A Single-Center Experience in China. J. Clin. Med. 2023, 12, 3782.

Error in Figure/Table [...].

Full-Right Full-Left Split Liver Transplantation for Two Adult Recipients: A Single-Center Experience in China.

BACKGROUND: The most effective treatment for end-stage liver diseases is liver transplantation, which is impeded by the shortage of donor livers. Split liver transplantation (SLT) is important for addressing the donor liver shortage. However, full-right full-left SLT for two adult recipients is globally rarely conducted. This study aimed to investigate the clinical outcomes of this technique. METHODS: We retrospectively analyzed the clinical data of 22 recipients who underwent full-right full-left SLT at Shulan (Hangzhou) Hospital between January, 2021 and September, 2022. The graft-to-recipient weight ratio (GRWR), cold ischemia time, operation time, length of the anhepatic phase, intraoperative blood loss, and red blood cell transfusion amount were all analyzed. The differences in liver function recovery after transplantation were compared between the left and right hemiliver groups. The postoperative complications and prognosis of the recipients were also analyzed. RESULTS: The livers of 11 donors were transplanted into 22 adult recipients. The GRWR ranged from 1.16-1.65%, the cold ischemia time was 282.86 ± 134.87 min, the operation time was 371.32 ± 75.36 min, the anhepatic phase lasted 60.73 ± 19.00 min, the intraoperative blood loss was 759.09 ± 316.84 mL, and the red blood cell transfusion amount was 695.45 ± 393.67 mL. No significant difference in the levels of liver function markers, total bilirubin, aspartate aminotransferase, or alanine aminotransferase between left and right hemiliver groups at 1, 3, 5, 7, 14, and 28 d postoperatively was observed (both p > 0.05). One recipient developed bile leakage 10 d after transplantation, which improved with endoscopic retrograde cholangiopancreatography-guided nasobiliary drainage and stent placement. Another developed portal vein thrombosis 12 d after transplantation and underwent portal vein thrombectomy and stenting to restore portal vein blood flow. A color Doppler ultrasound performed 2 d after transplantation revealed hepatic artery thrombosis in one patient, and thrombolytic therapy was administered to restore hepatic artery blood flow. The liver function of other patients recovered quickly after transplantation. CONCLUSIONS: Full-right full-left SLT for two adult patients is an efficient way to increase the donor pool. It is safe and feasible with careful donor and recipient selection. Transplant hospitals with highly experienced surgeons in SLT are recommended to promote using full-right full-left SLT for two adult recipients.

Nanosecond pulsed electric field stimulates CD103+ DC accumulation in tumor microenvironment via NK-CD103+ DC crosstalk.

CD103+ DC is crucial for antitumor immune response. As a promising local therapy on cancers, nanosecond pulsed electric field (nsPEF) has been widely reported to stimulate anti-tumor immune response, but the underlying relationship between intratumoral CD103+ DC and nsPEF treatment remains enigmatic. Here, we focused on the behavior of CD103+ DC in response to nsPEF treatment and explored the underlying mechanism. We found that the nsPEF treatment led to the activation and accumulation of CD103+ DC in tumor. Depletion of CD103+ DC via Batf3-/- mice demonstrated CD103+ DC was necessary for intratumoral CD8+ T cell infiltration and activation in response to nsPEF treatment. Notably, NK cells recruited CD103+ DC into nsPEF-treated tumor through CCL5. Inflammatory array revealed CD103+ DC-derived IL-12 mediated the CCL5 secretion in NK cells. In addition, the boosted activation and infiltration of intratumoral CD103+ DC were abolished by cGAS-STING pathway inhibition, following IL-12 and CCL5 decreasing. Furthermore, nsPEF treatment promoting CD103+ DC-mediated antitumor response enhanced the effects of CD47 blockade strategy. Together, this study uncovers an unprecedented role for CD103+ DC in nsPEF treatment-elicited antitumor immune response and elucidates the underlying mechanisms.

Combination with Toll-like receptor 4 (TLR4) agonist reverses GITR agonism mediated M2 polarization of macrophage in Hepatocellular carcinoma.

The glucocorticoid-induced tumor necrosis factor receptor (GITR) agonistic antibody (DTA-1) has been proved to elicit robust immune response in various kinds of tumors. However, only a few of the HCC patients could benefit from it, and the mechanism of DTA-1 resistance remains unknown. Here, we measured GITR expression in different immunocytes in HCC microenvironment, and we observed that tumor-infiltrating regulatory T cells (Ti-Tregs) significantly expressed GITR, which were associated with poor prognosis. Meanwhile, we analyzed the variation of tumor-infiltrating immune components and associated inflammation response after DTA-1 treatment in orthotopic liver cancer model of mice. Surprisingly, DTA-1 treatment reduced the infiltration of Tregs but failed to activate CD8+ T cells and elicit antitumor efficacy. In particular, DTA-1 treatment enforced alternative M2 polarization of macrophage, and macrophage depletion could enhance DTA-1-mediated antitumor efficacy in HCC. Mechanistically, macrophage M2 polarization attributed to the IL-4 elevation induced by Th2 immune activation in the treatment of DTA-1, resulting in DTA-1 resistance. Furthermore, Toll-like receptor 4 (TLR4) agonist could diminish the macrophage (M2) polarization and reverse the M2-mediated DTA-1 resistance, eliciting robust antitumor effect in HCC. Our finding demonstrated that the TLR4 agonist synergized with DTA-1 was a potential strategy for HCC treatment.

Blocking exposed PD-L1 elicited by nanosecond pulsed electric field reverses dysfunction of CD8+ T cells in liver cancer.

As a promising method for local tumor treatment, nanosecond pulsed electric field (nsPEF) ablation elicits a potent anti-tumor immune response. However, the mechanism of the nsPEF-mediated anti-tumor immune response and its effects on the tumor microenvironment remains unclear. Here, we demonstrated that nsPEF treatment increased the level of membrane PD-L1 in liver cancer cells. Furthermore, nsPEF induced the release of PD-L1-associated extra-cellular vesicles, leading to the dysfunction of CD8+ T cells, which could potentially be reversed by PD-L1 blockade. Biological and functional assays also demonstrated that nsPEF treatment resulted in the increased PD-L1 level and dysfunction of infiltrated CD8+ T cells in tumor tissues in vivo, indicating the long term antitumor efficacy of nsPEF treatment. A combination of nsPEF treatment and PD-L1 blockade effectively inhibited tumor growth and improved the survival of the tumor-bearing mouse. In conclusion, nsPEF treatment induced the translocation and release of PD-L1 and contributed to the dysfunction of infiltrated CD8+ T cells, resulting in tumor progression at later stages. The combination of nsPEF treatment and PD-L1 blockade is a promising therapeutic strategy for liver cancer.

Correction to: PHF8 upregulation contributes to autophagic degradation of E-cadherin, epithelial-mesenchymal transition and metastasis in hepatocellular carcinoma.

In the publication of our publication [1], we have noticed there is a wrong label in Fig. 1e, in which the position of "HCC" and "Adjacent" should be transposed.

Correction to: PHF8 upregulation contributes to autophagic degradation of E-cadherin, epithelial-mesenchymal transition and metastasis in hepatocellular carcinoma.

In the publication of this article [1], there are two inadvertent errors.

PHF8 upregulation contributes to autophagic degradation of E-cadherin, epithelial-mesenchymal transition and metastasis in hepatocellular carcinoma.

BACKGROUND: Plant homeodomain finger protein 8 (PHF8) serves an activator of epithelial-mesenchymal transition (EMT) and is implicated in various tumors. However, little is known about PHF8 roles in hepatocellular carcinoma (HCC) and regulating E-cadherin expression. METHODS: PHF8 expression pattern was investigated by informatic analysis and verified by RT-qPCR and immunochemistry in HCC tissues and cell lines. CCK8, xenograft tumor model, transwell assay, and tandem mCherry-GFP-LC3 fusion protein assay were utilized to assess the effects of PHF8 on proliferation, metastasis and autophagy of HCC cells in vitro and in vivo. ChIP, immunoblot analysis, rescue experiments and inhibitor treatment were used to clarify the mechanism by which PHF8 facilitated EMT, metastasis and autophagy. RESULTS: PHF8 upregulation was quite prevalent in HCC tissues and closely correlated with worse overall survival and disease-relapse free survival. Furthermore, PHF8-knockdown dramatically suppressed cell growth, migration, invasion and autophagy, and the expression of SNAI1, VIM, N-cadherin and FIP200, and increased E-cadherin level, while PHF8-overexpression led to the opposite results. Additionally, FIP200 augmentation reversed the inhibited effects of PHF8-siliencing on tumor migration, invasion and autophagy. Mechanistically, PHF8 was involved in transcriptionally regulating the expression of SNAI1, VIM and FIP200, rather than N-cadherin and E-cadherin. Noticeably, E-cadherin degradation could be accelerated by PHF8-mediated FIP200-dependent autophagy, a crucial pathway complementary to transcriptional repression of E-cadherin by SNAI1 activation. CONCLUSION: These findings suggested that PHF8 played an oncogenic role in facilitating FIP200-dependent autophagic degradation of E-cadherin, EMT and metastasis in HCC. PHF8 might be a promising target for prevention, treatment and prognostic prediction of HCC.