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.

Dynamic ginsenoside-sheltered nanocatalysts for safe ferroptosis-apoptosis combined therapy.

Chemodynamic therapy (CDT)-activated apoptosis is a potential anticancer strategy. However, CDT encounters a bottleneck in clinical translation due to its serious side effects and low efficacy. Here, we first reveal that surface engineering of ginsenoside Rg3 dramatically alters the organ distribution and tumor enrichment of systematically administered nanocatalysts using the orthotopic pancreatic tumor model while avoiding toxicity and increasing efficacy in vivo to address the key and universal toxicity problems encountered in nanomedicine. Compared with nanocatalysts alone, Rg3-sheltered dynamic nanocatalysts form hydrophilic nanoclusters, prolonging their circulation lifespan in the blood, protecting the internal nanocatalysts from leakage while allowing their specific release at the tumor site. Moreover, the nanoclusters provide a drug-loading platform for Rg3 so that more Rg3 reaches the tumor site to achieve obvious synergistic effect with nanocatalysts. Rg3-sheltered dynamic nanocatalysts can simultaneously activate ferroptosis and apoptosis to significantly improve anticancer efficacy. Systematic administration of ginsenoside Rg3-sheltered nanocatalysts inhibited 86.6% of tumor growth without toxicity and prolonged the survival time of mice. This study provides a promising approach of nanomedicine with high biosafety and a new outlook for catalytic ferroptosis-apoptosis combined antitumor therapies. STATEMENT OF SIGNIFICANCE: Chemodynamic therapy (CDT) has limited clinical efficacy in cancer. In this study, we developed Rg3-sheltered dynamic nanocatalysts, which could simultaneously activate ferroptosis based on CDT-activated apoptosis, and ultimately form a combined therapy of ferroptosis-apoptosis to kill tumors. Studies have shown that the nanocatalysts after Rg3 surface engineering dramatically alters the pharmacokinetics and organ distribution of the nanocatalysts after being systematically administered, resulting in avoiding the toxicity of the nanocatalysts. Nanocatalysts also act as a drug-loading platform, guiding more Rg3 into the tumor site. This study emphasizes that nanocatalysts after Rg3 surface engineering improve the safety and effectiveness of ferroptosis-apoptosis combined therapy, providing an effective idea for clinical practices.

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.

Sox15 Methylation Inhibits Cell Proliferation Through Wnt Signaling in Hepatocellular Carcinoma.

The expression of the SRY-Box Transcription Factor 15 (Sox15) is reduced by DNA methylation, and its progression is suppressed within numerous tumors. However, its effect on hepatocellular carcinoma (HCC) remains unknown. In the present work, the clinical importance and function of Sox15, as well as the underlying molecular mechanism, were explored within HCC. The expression of Sox15 is reduced and positively correlated with prognosis in HCC as analyzed by GEPIA (Gene Expression Profiling Interactive Analysis) and OncoLnc. Meanwhile, the hypermethylated Sox15 promoter CpG-site predicted a dismal HCC prognosis. Besides, ectopic Sox15 expression within the HCC cells (LM3, HUH7, SK-hep-1) remarkably inhibited in vitro cell growth and inhibited xenograft tumorigenesis in the nude mice. Moreover, Sox15 inactivated the Wnt pathway under both in vivo and in vitro conditions. To summarize, Sox15 played a tumor suppressor role within the HCC via the inactivated Wnt pathway. Sox15 and CpG-site methylation of its promoter are the factors that independently predict the prognosis of HCC.

Self-assembly nanovaccine containing TLR7/8 agonist and STAT3 inhibitor enhances tumor immunotherapy by augmenting tumor-specific immune response.

BACKGROUND: Cancer vaccines are a promising strategy for cancer immunotherapy. Cancer vaccines elicits a specific cytotoxic immune response to tumor antigens. However, the efficacy of traditional peptide-based cancer vaccines is limited due to the inefficient delivery of antigens and adjuvants to dendritic cells (DCs). Therefore, it is necessary to develop a novel rationally designed cancer vaccine to maximize its desired effects. METHODS: A Self-assembling Vehicle-free Multi-component Antitumor nanoVaccine (SVMAV) was constructed by using an unsaturated fatty acid docosahexaenoic acid (DHA)-conjugated antigen and R848 (a Toll-like receptor 7/8 agonist) to encapsulate stattic (a signal transducer and activator of transcription 3 inhibitor). The characteristics of SVMAV were investigated. The ability of SVMAV to promote DC functions was examined by in vitro analysis. The antitumor effects of SVMAV and its combination with antiprogrammed cell death protein 1 antibody (aPD-1) were also investigated in vivo. The potential application of SVMAV for neoantigen-targeted, personalized cancer vaccines was examined in an orthotopic hepatocellular carcinoma model. RESULTS: The obtained SVMAV efficiently migrated into lymph nodes and primed CD8+ T cells for exert neoantigen-specific killing by promoting the antigen uptake by DCs, stimulating DC maturation, and enhancing antigen cross-presentation, due to the simultaneous delivery of the antigen, R848 and stattic. SVMAV could not only yield a robust antitumor effect for primary melanoma allografts, but also exert a protective effect for lung metastases. Moreover, combination treatment of SVMAV and aPD-1 exerted synergistic antitumor activity and extended the survival duration of melanoma-bearing mice. Notably, a cell line-specific neoantigen-based SVMAV was designed according to predicted neoantigens for Hepa1-6 cells to examine the potential application of SVMAV for personalized cancer vaccine. Encouragingly, neoantigen-specific SVMAV achieved stronger antitumor activity than aPD-1 in an orthotopic hepatocellular cancer model established with Hepa1-6 cells. CONCLUSIONS: In summary, this study offers an efficient codelivery platform for neoantigens and immunoregulatory compounds to enhance immune responses during cancer immune therapy.

Targeting peripheral immune organs with self-assembling prodrug nanoparticles ameliorates allogeneic heart transplant rejection.

Organ transplantation has become a mainstay of therapy for patients with end-stage organ diseases. However, long-term administration of immunosuppressive agents, a scheme for improving the survival of transplant recipients, has been compromised by severe side effects and posttransplant complications. Therapeutic delivery targeting immune organs has the potential to address these unmet medical issues. Here, through screening of a small panel of mammalian target of rapamycin complex kinase inhibitor (TORKinib) compounds, a TORKinib PP242 is identified to be able to inhibit T cell function. Further chemical derivatization of PP242 using polyunsaturated fatty acids (i.e., docosahexaenoic acid) transforms this water-insoluble hydrophobic agent into a self-assembling nanoparticle (DHA-PP242 nanoparticle [DPNP]). Surface PEGylation of DPNP with amphiphilic copolymers renders the nanoparticles aqueously soluble for preclinical studies. Systemically administered DPNP shows tropism for macrophages within peripheral immune organs. Furthermore, DPNP regulates differentiation of adoptively transferred T cells in a macrophage-dependent manner in Rag1-/- mouse model. In an experimental model of heart transplantation, DPNP significantly extends the survival of grafts through inducing immune suppression, thus reducing the inflammatory response of the recipients. These findings suggest that targeted delivery of TORKinibs exploiting prodrug-assembled nanoparticle scaffolds may provide a therapeutic option against organ rejection.

Nanoparticle formulation of mycophenolate mofetil achieves enhanced efficacy against hepatocellular carcinoma by targeting tumour-associated fibroblast.

Hepatocellular carcinoma (HCC) is one of the most aggressive tumours with marked fibrosis. Mycophenolate mofetil (MMF) was well-established to have antitumour and anti-fibrotic properties. To overcome the poor bioavailability of MMF, this study constructed two MMF nanosystems, MMF-LA@DSPE-PEG and MMF-LA@PEG-PLA, by covalently conjugating linoleic acid (LA) to MMF and then loading the conjugate into polymer materials, PEG5k -PLA8k and DSPE- PEG2k , respectively. Hepatocellular carcinoma cell lines and C57BL/6 xenograft model were used to examine the anti-HCC efficacy of nanoparticles (NPs), whereas NIH-3T3 fibroblasts and highly-fibrotic HCC models were used to explore the anti-fibrotic efficacy. Administration of NPs dramatically inhibited the proliferation of HCC cells and fibroblasts in vitro. Animal experiments revealed that MMF-LA@DSPE-PEG achieved significantly higher anti-HCC efficacy than free MMF and MMF-LA@PEG-PLA both in C57BL/6 HCC model and highly-fibrotic HCC models. Immunohistochemistry further confirmed that MMF-LA@DSPE-PEG dramatically reduced cancer-associated fibroblast (CAF) density in tumours, as the expression levels of alpha-smooth muscle actin (α-SMA), fibroblast activation protein (FAP) and collagen IV were significantly downregulated. In addition, we found the presence of CAF strongly correlated with increased HCC recurrence risk after liver transplantation. MMF-LA@DSPE-PEG might act as a rational therapeutic strategy in treating HCC and preventing post-transplant HCC recurrence.

The synthesis of a nanodrug using metal-based nanozymes conjugated with ginsenoside Rg3 for pancreatic cancer therapy.

Nanozymes have limited applications in clinical practice due to issues relating to their safety, stability, biocompatibility, and relatively low catalytic activity in the tumor microenvironment (TME) in vivo. Herein, we report a synergistic enhancement strategy involving the conjugation of metal-based nanozymes (Fe@Fe3O4) with natural bioactive organic molecules (ginsenoside Rg3) to establish a new nanodrug. Importantly, this metal-organic nanocomposite drug ensured the stability and biosafety of the nanozyme cores and the cellular uptake efficiency of the whole nanodrug entity. This nanodrug is based on integrating the biological characteristics and intrinsic physicochemical properties of bionics. The glycoside chain of Rg3 forms a hydrophilic layer on the outermost layer of the nanodrug to improve the biocompatibility and pharmacokinetics. Additionally, Rg3 can activate apoptosis and optimize the activity and status of normal cells. Internal nanozymes enter the TME and release Fe3+ and Fe2+, and the central metal Fe(0) continuously generates highly active Fe2+ under the conditions of the TME and in the presence of Fe3+, maintaining the catalytic activity. Therefore, these nanozymes can effectively produce reactive oxygen species and oxygen in the TME, thereby promoting the apoptosis of cancer cells. Thus, we propose the use of a new type of metal-organic nanocomposite material as a synergistic strategy against cancer.

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.

Ultrastructural changes in hepatocellular carcinoma cells induced by exponential pulses of nanosecond duration delivered via a transmission line.

Clinical applications of high-intensity pulsed electric fields have proven useful in ablating solid tumors. However, novel ideas for the development of an effective tumor ablation device are urgently needed. Here, we studied cellular effects of the nanosecond exponential pulse, which is generated by a capacitor-discharging circuit and delivered via a transmission line. Pulses of peak voltage boosted by transmission line oscillation possess high capability to induce swelling and to cause loss of viability in cells. The appropriate parameter of the pulse was selected to investigate the ultrastructural changes in swollen cells, which present smoothened plasma membrane, loss of microvilli, and lowered cytoplasm electron density. We propose the equivalent force field hypothesis to understand the mechanism underlying cell swelling induced by pulsing. Wrinkles on the plasma membrane might indicate recovery from cell swelling, and this was verified by co-culture of pulsed PKH26-Cells with sham-treated PKH67-Cells. We concluded that the ultrastructural changes, such as irregular pores formed on the plasma membrane, were mainly induced by the effect of electric pulse applied on the charged molecules in the membrane.

Upregulation of PDGF Mediates Robust Liver Regeneration after Nanosecond Pulsed Electric Field Ablation by Promoting the HGF/c-Met Pathway.

Nanosecond pulsed electric field (nsPEF) has emerged as a promising tool for hepatocellular carcinoma ablation recently. However, little is known about how nsPEF affects liver regeneration while being applied to eliminate liver lesions. Besides, the impact of nsPEF ablation on liver function should also be taken into consideration in the process. In this paper, we study the impact of nsPEF ablation on liver function by the measurement of serum levels of AST and ALT as well as liver regeneration and relevant molecular mechanisms in vivo. We found that mouse liver function exhibited a temporary injury without weight loss after ablation. In addition, local hepatic nsPEF ablation promoted significant proliferation of hepatocytes of the whole liver with an increase in HGF level. Moreover, the proliferation of hepatocytes was dramatically inhibited by the inhibitor of c-Met. Of interest, the periablational area is characterized by high level of PDGF and a large amount of activated hepatic stellate cells. Furthermore, neutralizing PDGF was able to significantly inhibit liver regeneration, the increased HGF level, and the accumulation of activated HSCs. Our findings demonstrated that nsPEF not only was a safe ablation approach but also could stimulate the regeneration of the whole liver through the activation of the HGF/c-Met pathway by upregulation of PDGF within the periablational zone.

Protein Profiles of Pretransplant Grafts Predict Early Allograft Dysfunction After Liver Transplantation From Donation After Circulatory Death.

BACKGROUND: Predicting the development of early allograft dysfunction (EAD) following liver transplantation (LT) remains challenging for transplant clinicians. The objectives of this study are to investigate the potential relationship between the protein profiles of pretransplant grafts and the onset of EAD, and then combine with clinical parameters to construct a mathematically predictive model. METHODS: Clinical data of 121 LT procedures from donation after circulatory death at the authors' center were analyzed. The expression levels of 7 studied proteins were determined by immunohistochemistry. Another independent cohort of 37 subjects was designed for further validation of the predictive model. RESULTS: With an incidence of 43.0% (52/121), EAD was linked to significantly increased risk of acute kidney injury and renal replacement therapy, as well as reduced 6-month patient and liver graft survival. Allograft weight and high intrahepatic vascular endothelial growth factor (VEGF) expression were identified as independent risk factors of EAD and survival outcomes. Liver grafts with high VEGF expression exhibited delayed functional recovery within the first postoperative week. The combination of VEGF overexpression and EAD yielded the highest frequency of renal dysfunction and the worst survival. Based on allograft weight and intrahepatic VEGF expression, an EAD risk assessment model was developed. The incidence of EAD differed significantly between grafts with risk scores ≥-1.72 and <-1.72. The model functioned well in the validation cohort. CONCLUSIONS: Pretransplant intrahepatic protein profiling contributes to the estimation of early graft performance and recipient outcomes following LT. The predictive model could allow for an accurate prediction of EAD.

KCa3.1 as an Effective Target for Inhibition of Growth and Progression of Intrahepatic Cholangiocarcinoma.

Background: Intrahepatic cholangiocarcinoma (ICC) is a high malignant tumor arising from the bile ducts in the liver with a poor prognosis. As current molecular targeted therapies and systemic chemotherapies had limited success in ICC, novel therapeutic targets are needed. In this study, we attempted to investigate the expression and the role of the intermediate conductance calcium-activated potassium channel (KCa3.1) in ICC. Methods: The expression levels of KCa3.1 channel were measured in 81 resected ICC tumor specimens and the clinicopathological significance of these levels were determined. KCa3.1 channel inhibitor and siRNA were used to study the role of KCa3.1 in proliferation, migration, and invasion of ICC cell lines. The effect of KCa3.1 channel blockade on tumor growth in vivo was also studied using xenograft model in nude mice. Results: The protein expression of KCa3.1 channel was upregulated in ICC tissues and was correlated with age, lymph node metastasis and TNM stage. And high KCa3.1 expression indicated a worse prognosis in ICC patients. Blocking KCa3.1 channel with a specific inhibitor TRAM-34 reduced the proliferation and invasion of ICC cells. Knockdown of KCa3.1 could achieve the same effects through decreasing NF-κB activation. Further in vivo studies demonstrated that KCa3.1 channel blockade suppressed ICC tumor growth. Conclusions: Our observations suggested KCa3.1 might be a promising novel therapeutic target in intrahepatic cholangiocarcinoma.

The local liver ablation with pulsed electric field stimulate systemic immune reaction against hepatocellular carcinoma (HCC) with time-dependent cytokine profile.

AIM: How irreversible electroporation (IRE) affect immune status is still kept unknown. This preclinical study is to investigate its local and systemic immune reaction both on tumor-bearing and tumor free animals. METHODS: Liver ablation was performed by a standard IRE instrument and proposal. Altogether 57 tumor bearing mice and 10 tumor-free porcine livers were ablated. The reaction of survival, radiology image, pathologically and immunologically were followed up. The detailed cytokines and chemokines responses were recorded dynamically post IRE ablation. RESULTS: IRE ablation induced coagulation and necrosis in liver. It caused macrophages infiltration, in ablation zone. IRE ablation caused cellular inflammation. It, corrected the abnormal drifted Th2 in HCC back to Th1 status, promoting tumor eradication and host survival. The quantified cytokines and chemokines indicate IRE can stimulate both local immune reaction and systemic immune reaction. CONCLUSION: Local IRE ablation changes the abnormal drifted Th2 in HCC back to Th1 status, facilitating tumor eradication and host survival.

Bile deficiency induces changes in intestinal glucose absorption in mice.

BACKGROUND: Biliary tract obstruction is a common clinical problem. In this study, we attempted to understand the change in intestinal glucose absorption after biliary tract obstruction. METHODS: Experimental models of murine biliary duct ligation and external biliary drainage were established. Murine intestinal mucosal glucose absorption was examined with Ussing chambers according to the increase in the short-circuit current in vitro and blood glucose measurement after oral glucose in vivo. The protein expression of the sodium-glucose cotransporter (SGLT1) and the facilitated glucose transporter, member 2 (GLUT2) was analyzed by Western blot and immunohistochemistry. RESULTS: The results from Ussing chamber experiments showed that duodenal mucosal glucose absorption levels were significantly higher in biliary duct ligation and biliary drainage mice than those in normal control mice at 1 and 2 weeks after the operation. Gastrointestinal bile acid administration almost reversed the elevated duodenal mucosal glucose absorption to the normal level in biliary drainage mice. The results from the experiments in vivo further confirmed that the glucose absorption increased in biliary duct ligation and biliary drainage mice. The protein expression levels of SGLT1 in the duodenal mucosae of both biliary duct ligation and biliary drainage mice were markedly higher than those in control mice, and the protein expression of GLUT2 was not significantly altered, compared with control mice. CONCLUSION: Bile deficiency in the intestine upregulates the expression of intestinal mucosal SGLT1 and enhances intestinal mucosal glucose absorption capacity, which contributes to the understanding of intestinal physiologic function for patients with biliary duct obstruction and external biliary drainage.

Nanosecond pulsed electric field (nsPEF) enhance cytotoxicity of cisplatin to hepatocellular cells by microdomain disruption on plasma membrane.

Previous studies showed nanosecond pulsed electric field (nsPEF) can ablate solid tumors including hepatocellular carcinoma (HCC) but its effect on cell membrane is not fully understood. We hypothesized nsPEF disrupt the microdomains on outer-cellular membrane with direct mechanical force and as a result the plasma membrane permeability increases to facilitate the small molecule intake. Three HCC cells were pulsed one pulse per minute, an interval longer than nanopore resealing time. The cationized ferritin was used to mark up the electronegative microdomains, propidium iodide (PI) for membrane permeabilization, energy dispersive X-ray spectroscopy (EDS) for the negative cell surface charge and cisplatin for inner-cellular cytotoxicity. We demonstrated that the ferritin marked-microdomain and negative cell surface charge were disrupted by nsPEF caused-mechanical force. The cell uptake of propidium and cytotoxicity of DNA-targeted cisplatin increased with a dose effect. Cisplatin gains its maximum inner-cellular cytotoxicity when combining with nsPEF stimulation. We conclude that nsPEF disrupt the microdomains on the outer cellular membrane directly and increase the membrane permeabilization for PI and cisplatin. The microdomain disruption and membrane infiltration changes are caused by the mechanical force from the changes of negative cell surface charge.