Tumor microenvironment enhanced NIR II fluorescence imaging for tumor precise surgery navigation via tetrasulfide mesoporous silica-coated Nd-based rare-earth nanocrystals

In vivo fluorescent imaging by using the new contrast agents emitted at short-wavelength infrared region (NIR II, 1000-1700 ​nm) presents an unprecedent advantages in imaging sensitivity and spatial resolution over traditional near-infrared (NIR) light. Recently, Nd-based rare-earth nanocrystals have attracted considerable attention due to the high quantum yield (∼40%) of their emission at NIR II. However, undesirable capture by reticuloendothelial system to bring strong background signal is unsatisfying for tumor discrimination. Here, GSH-sensitive tetrasulfide bond incorporated mesoporous silica shell has entrusted onto Nd-based down-conversion nanocrystals (DCNPs) surface to totally quench the fluorescence of DCNPs. After RGD conjugation on the silica surface, the NIR II contrast agents could actively target to liver tumors. Then tetrasulfide bonds can be broken during the silica framework decomposing in cytoplasm under high GSH concentration to result in NIR II fluorescence explosive recover. Benefiting from this specific response under tumor microenvironment, the NIR II signal in other organs was markedly reduced, while the signal-to-background ratio is prominently enhanced in tumors. Then, solid liver tumors were successfully resected under the guidance of our GSH responsive NIR II fluorescent imaging with no recurrence after 20-day of surgery. Meanwhile, by combining with the ignorable side effects, the Nd-based nanoprobes vastly improved the imaging resolution of tumor margin, opening a paradigm of NIR II fluorescent imaging-guided surgery.

CD16/PD-L1 bi-specific aptamer for cancer immunotherapy through recruiting NK cells and acting as immunocheckpoint blockade

It is well established that natural killer (NK) cells can be used as an alternative candidate of T cells for adoptive cell therapy (ACT) due to its high killing capacity, off-the-shelf utility, and low toxicity. Though NK cells provide rapid and potent immune effects, they still suffer from insufficient infiltration and tumor immunosuppression environment, which result in unsatisfactory therapeutic efficiency. Herein, a highly stable CD16/PD-L1 bi-specific aptamer (defined as CP-bi-apt) with high affinity and selectivity was introduced to overcome these obstacles. This CP-bi-apt can mediate a significant antitumor immunity by recruiting CD16-positive NK cells to directly contact with PD-L1 high-expressed tumor cells. In addition, the induced up-regulation of PD-L1 on tumor cells can inevitably occur as an adaptive response to most of the immunotherapeutic strategies. The prepared CP-bi-apt can be further used as an immune checkpoint inhibitor to specifically bind to PD-L1, thus reducing the negative impact of PD-L1 over-expression on the therapeutic efficacy. Furthermore, this CP-bi-apt-based immunotherapy is simple, highly efficient, and has low side effects, showing a promising potential for clinical translation.

Core-shell NaGdF4@CaCO3 nanoparticles for enhanced magnetic resonance/ultrasonic dual-modal imaging via tumor acidic micro-enviroment triggering

For cancer diagnosis, a paramount challenge still exists in the exploring of methods that can precisely discriminate tumor tissues from their surrounding healthy tissues with a high target-to-background signal ratio. Here, we report a NaGdF4@CaCO3-PEG core-shell nanoparticle which has the tumor acidic microenvironment enhanced imaging signals of ultrasound and magnetic resonance. Under the acidic conditions, the CaCO3 shell will gradually dissolve which then facilitate the interaction of NaGdF4 with the external aqueous environment to enhance water proton relaxation. Meanwhile, the CO2 bubbles generated by the CaCO3 dissolvement will generate strong elastic echo for US detection. The core-shell structure of NaGdF4@CaCO3-PEG can be observed by TEM, and its composition can be determined by STEM. The acid triggered generation of CO2 bubbles and the enhancement of MRI signal could be demonstrated in vitro, and the excellent dual-modal magnetic resonance/ultrasonic cancer imaging abilities of NaGdF4@CaCO3-PEG could be also proved at the tumor site in vivo. The here described proof-of-concept nanoparticles with pH triggered magnetic resonance/ultrasonic dual-modal imaging enhancement, may serve as a useful guide to develop various molecular imaging strategies for cancer diagnosis in the future.

3D-cultured adipose tissue-derived stem cells inhibit liver cancer cell migration and invasion through suppressing epithelial-mesenchymal transition

Adipose tissue-derived stem cells (ADSCs) are considered promising candidates for stem cell therapy; however, the tumorigenicity of ADSCs remains controversial. The present study aimed to investigate the association between ADSCs and liver cancer cells, and to determine whether culture methods could influence the effects of ADSCs on liver cancer cell growth in vitro. Liver cancer cells were treated with ADSCs-conditioned medium (CM) that was collected using the two-dimensional (2D) culture method, sphere culture method, or three-dimensional (3D) culture method. After that, cell viability and apoptosis were measured using CCK-8 and Annexin V-FITC assay, respectively; the cell motility and adhesive capacity were analyzed by scratch wound healing and cell adhesion assay, respectively; the cell migration and invasion were examined by Transwell units; and the molecular mechanisms of ADSCs on effecting epithelial mesenchymal transition signaling pathway were further analyzed. The results demonstrated that ADSCs‑CM was able to inhibit the growth of liver cancer cells by inhibiting cell proliferation and promoting cell apoptosis, as well as by suppressing cell motility, adhesive capacity, migration and invasion. In addition, ADSCs‑CM was able to suppress cell growth via the downregulation of epithelial‑mesenchymal transition signaling. Notably, the enhanced inhibitory effects of ADSCs on liver cancer cell growth could be achieved after cultu-ring using a 3D approach. These findings suggested that ADSCs may provide a novel promising therapeutic approach for the treatment of patients with liver cancer, and the 3D culture method may provide a novel approach to explore the association between ADSCs and cancer.

Protocol to prepare functional cellular nanovesicles with PD1 and TRAIL to boost antitumor response

Immunotherapy has achieved notable success in tumor treatment, but it is restricted to a small number of patients due to multiple immunosuppressive pathways in the tumor microenvironment. Here, we present a step-by-step protocol to prepare functional cellular nanovesicles from HEK293-FT cells displaying PD1 and TRAIL. TRAIL specifically induces immunogenic cancer cell death to initiate an immune response, and ectogenic PD1 blocks the PD1/PDL1 checkpoint signal to reactivate anergic tumor-specific CD8+ T cells. For complete details on the use and execution of this protocol, please refer to Wu et al. (2020).

Highly efficient redox reaction between potassium permanganate and 3,3',5,5'-tetramethylbenzidine for application in hydrogen peroxide based colorimetric assays

Potassium permanganate (KMnO4) is one of the most important oxidants, which plays important roles in many fields. Here, we found that KMnO4 could directly induce the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to generate an oxidized product with a color change. This redox reaction is highly efficient, and 1 μM KMnO4 is enough to cause detectable changes in the absorbance signal. Meanwhile, this reaction is very fast and the generated blue product can stabilize for a relatively long period, which has great advantages in practical applications. Since hydrogen peroxide (H2O2) is able to react with KMnO4 under acidic conditions, the KMnO4-TMB system can be used for the detection of H2O2; the absorbance signal induced by 5 μM H2O2 can be easily detected in this method. Meanwhile, the KMnO4-TMB system can also be used for the detection of glucose by monitoring the generation of H2O2, which is the main product of glucose oxidation; this method permits detection of concentrations as low as 10 μM glucose, and the sensitivity is comparable to or higher than most peroxidase mimetic based methods, but avoiding the preparation and storage of the nanomaterials. Furthermore, the KMnO4-TMB system can even be used for analyzing glucose in serum samples, which can also be expected to be used in immunoassays.

Quantitative Secretome Analysis Reveals Clinical Values of Carbonic Anhydrase II in Hepatocellular Carcinoma

Early detection and intervention are key strategies to reduce mortality, increase long-term survival, and improve the therapeutic effects of hepatocellular carcinoma (HCC) patients. Herein, the isobaric tag for relative and absolute quantitation (iTRAQ)-based quantitative proteomic strategy was used to study the secretomes in conditioned media from HCC cancerous tissues, surrounding noncancerous tissues, and distal noncancerous tissues to identify diagnostic and prognostic biomarkers for HCC. In total, 22 and 49 dysregulated secretory proteins were identified in the cancerous and surrounding noncancerous tissues, respectively, compared with the distal noncancerous tissues. Among these proteins, carbonic anhydrase II (CA2) was identified to be significantly upregulated in the secretome of cancerous tissues; correspondingly, the serum concentrations of CA2 were remarkably increased in HCC patients compared with that in normal populations. Interestingly, a significant increase of serum CA2 in recurrent HCC patients after radical resection was also confirmed compared with HCC patients without recurrence, and the serum level of CA2 could act as an independent prognostic factor for time to recurrence and overall survival. Regarding the mechanism, the secreted CA2 enhances the migration and invasion of HCC cells by activating the epithelial mesenchymal transition pathway. Taken together, this study identified a novel biomarker for HCC diagnosis and prognosis, and provided a valuable resource of HCC secretome for investigating serological biomarkers.

Death-associated protein kinase 1 suppresses hepatocellular carcinoma cell migration and invasion by upregulation of DEAD-box helicase 20

Death-associated protein kinase 1 (DAPK) is a calcium/calmodulin kinase that plays a vital role as a suppressor gene in various cancers. Yet its role and target gene independent of p53 is still unknown in hepatocellular carcinoma (HCC). In this study, we discovered that DAPK suppressed HCC cell migration and invasion instead of proliferation or colony formation. Using a proteomics approach, we identified DEAD-box helicase 20 (DDX20) as an important downstream target of DAPK in HCC cells and critical for DAPK-mediated inhibition of HCC cell migration and invasion. Using integrin inhibitor RGD and GTPase activity assays, we discovered that DDX20 suppressed HCC cell migration and invasion through the CDC42-integrin pathway, which was previously reported as an important downstream pathway of DAPK in cancer. Further research using cycloheximide found that DAPK attenuates the proteasomal degradation of DDX20 protein, which is dependent on the kinase activity of DAPK. Our results shed light on new functions and regulation for both DAPK and DDX20 in carcinogenesis and identifies new potential therapeutic targets for HCC.

Human serum albumin as the carrier to fabricate STING-activating peptide nanovaccine for antitumor immunotherapy

Tumor vaccines are emerging as one of the most promising therapeutic strategies for cancer treatment. With the advantages of low toxicity, convenient production and stable quality control, peptide vaccines have been widely used in preclinical and clinical trials involving various malignancies. However, when used alone, they still suffer from significant challenges including poor stability and immunogenicity as well as the low delivery efficiency, leading to limited therapeutic success. Herein, the STING-activating peptide nanovaccine based on human serum albumin (HSA) and biodegradable MnO2 was constructed, which can improve the stability and immunogenicity of antigenic peptides as well as facilitate their uptake by dendritic cells (DCs). Meanwhile, Mn2+ degraded from the nanovaccine can activate the STING pathway and further promote DCs maturation. In this way, the prepared nanovaccine can efficiently mediate T-cell immune responses, thereby exerting the effects of tumor prevention and therapy. Moreover, the prepared nanovaccine possesses the advantages of low cost, convenient preparation and good biocompatibility, showing great potential for practical applications.

Growing Human Hepatocellular Tumors Undergo a Global Metabolic Reprogramming

Hepatocellular carcinoma (HCC) is a common malignancy with poor prognosis, high morbidity and mortality concerning with lack of effective diagnosis and high postoperative recurrence. Similar with other cancers, HCC cancer cells have to alter their metabolism to adapt to the changing requirements imposed by the environment of the growing tumor. In less vascularized regions of tumor, cancer cells experience hypoxia and nutrient starvation. Here, we show that HCC undergoes a global metabolic reprogramming during tumor growth. A combined proteomics and metabolomics analysis of paired peritumoral and tumor tissues from 200 HCC patients revealed liver-specific metabolic reprogramming and metabolic alterations with increasing tumor sizes. Several proteins and metabolites associated with glycolysis, the tricarboxylic acid cycle and pyrimidine synthesis were found to be differentially regulated in serum, tumor and peritumoral tissue with increased tumor sizes. Several prognostic metabolite biomarkers involved in HCC metabolic reprogramming were identified and integrated with clinical and pathological data. We built and validated this combined model to discriminate against patients with different recurrence risks. An integrated and comprehensive metabolomic analysis of HCC is provided by our present work. Metabolomic alterations associated with the advanced stage of the disease and poor clinical outcomes, were revealed. Targeting cancer metabolism may deliver effective therapies for HCC.

Lnc-CCNH-8 promotes immune escape by up-regulating PD-L1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignancy with poor prognosis. In recent years, immune checkpoint inhibitors (ICIs) have enabled breakthroughs in the clinical treatment of patients with HCC, but the overall response rate to ICIs in HCC patients is still low, and no validated biomarker is available to guide clinical decision making. Here, we demonstrated that the long non-coding RNA Lnc-CCNH-8 is highly expressed in HCC and correlates with poor prognosis. Functionally, elevated Lnc-CCNH-8 inactivated co-cultured T cells in vitro and compromised antitumor immunity in an immunocompetent mouse model. Mechanistically, up-regulated Lnc-CCNH-8 can sponge microRNA (miR)-217 to regulate the expression of PD-L1. In addition, Lnc-CCNH-8 can also stabilize PD-L1 through miR-3173/PKP3 axis. Furthermore, mice bearing tumors with high Lnc-CCNH-8 expression had significant therapeutic sensitivity to anti-PD-L1 monoclonal antibody treatment. More important, HCC patients with high levels of plasma exosomal Lnc-CCNH-8 had a better therapeutic response to ICIs. Taken together, our results reveal the function of Lnc-CCNH-8 in inducing immune escape from CD8+ T-cell-mediated killing by up-regulating PD-L1 in a miR-217/miR-3173-dependent manner, which also reveals a novel mechanism of PD-L1 regulation in HCC, and exosomal Lnc-CCNH-8 can serve as a predictive marker for immunotherapy response in HCC.

Comparative proteomics of side population cells derived from human hepatocellular carcinoma cell lines with varying metastatic potentials

Metastasis and recurrence following surgery are major reasons for the high mortality rate and poor prognosis associated with hepatocellular carcinoma (HCC). Cancer stem cells (CSCs) are thought to be able to cause cancer, and to be the primary cause of tumor recurrence and metastasis. The underlying mechanisms of the metastatic potential of CSCs is poorly understood. In the present study, side population (SP) cells were isolated from 4 HCC cell lines, and their self-renewal and migratory abilities were compared. The results demonstrate that SP cells from different cell lines exhibited similar self-renewal abilities but different metastatic potentials. Furthermore, the overall proteomes of the SP cells were systematically quantified. This revealed 11 and 19 differentially expressed proteins (DEPs), upregulated and downregulated, respectively, associated with increased metastatic potential. These proteins were involved in the 'regulation of mRNA processing' and 'cytoskeleton organization' biological processes. The majority of the proteins were involved in 'cell proliferation', 'migration' and 'invasion of cancer', and may promote HCC metastasis in a synergistic manner. The AKT and nuclear factor-κB signaling pathways may contribute to the regulation of HCC metastasis through regulating the DEPs in SP cells. To the best of our knowledge, the present study is the first to demonstrate the overall proteome difference among SP cells from the different HCC cell lines with different metastatic potentials. The present study provides novel information regarding the metastatic potential of CSCs, which will facilitate further investigation of the topic.

Accurate transcriptome assembly by Nanopore RNA sequencing reveals novel functional transcripts in hepatocellular carcinoma

The long reads of Nanopore sequencing permit accurate transcript assembly and ease in discovering novel transcripts with potentially important functions in cancers. The wide adoption of Nanopore sequencing for transcript quantification, however, is largely limited by high costs. To address this issue, we developed a bioinformatics software, NovelQuant, that can specifically quantify long-read-assembled novel transcripts with short-read sequencing data. Nanopore Direct RNA Sequencing was carried out on three hepatocellular carcinoma (HCC) patients' tumor, matched portal vein tumor thrombus, and peritumor to reconstruct the HCC transcriptome. Then, based on the reconstructed transcriptome, NovelQuant was applied on Illumina RNA sequencing data of 59 HCC patients' tumor and paired peritumor to quantify novel transcripts. Our further analysis revealed 361 novel transcripts dysregulated in HCC and that 101 of them were significantly associated with prognosis. There were 19 novel prognostic transcripts predicted to be long noncoding RNAs (lncRNAs), and some of them had regulatory targets that were reported to be associated with HCC. Additionally, 42 novel prognostic transcripts were predicted to be protein-coding mRNAs, and many of them could be involved in xenobiotic metabolism. Moreover, the tumor-suppressive roles of two representative novel prognostic transcripts, CDO1-novel (lncRNA) and CYP2A6-novel (protein-coding mRNA), were further functionally validated during HCC progression. Overall, the current study shows a possibility of combining long- and short-read sequencing to explore functionally important novel transcripts in HCC with accuracy and cost-efficiency, which expands the pool of molecular biomarkers that could enhance our understanding of the molecular mechanisms of HCC.

Scattering Inversion Study for Suspended Label-Free Lymphocytes with Complex Fine Structures

Objective and Impact Statement. Distinguishing malignant lymphocytes from normal ones is vital in pathological examination. We proposed an inverse light scattering (ILS) method for label-free suspended lymphocytes with complex fine structures to identify their volumes for pathological state. Introduction. Light scattering as cell's "fingerprint" provides valuable morphology information closely related to its biophysical states. However, the detail relationships between the morphology with complex fine structures and its scattering characters are not fully understood. Methods. To quantitatively inverse the volumes of membrane and nucleus as the main scatterers, clinical lymphocyte morphologies were modeled combining the Gaussian random sphere geometry algorithm by 750 reconstructed results after confocal scanning, which allowed the accurate simulation to solve ILS problem. For complex fine structures, the specificity for ILS study was firstly discussed (to our knowledge) considering the differences of not only surface roughness, posture, but also the ratio of nucleus to the cytoplasm and refractive index. Results. The volumes of membrane and nucleus were proved theoretically to have good linear relationship with the effective area and entropy of forward scattering images. Their specificity deviations were less than 3.5%. Then, our experimental results for microsphere and clinical leukocytes showed the Pearson product-moment correlation coefficients (PPMCC) of this linear relationship were up to 0.9830~0.9926. Conclusion. Our scattering inversion method could be effectively applied to identify suspended label-free lymphocytes without destructive sample pretreatments and complex experimental systems.

Copy number profiling of circulating free DNA predicts transarterial chemoembolization response in advanced hepatocellular carcinoma

Transarterial chemoembolization (TACE) is the most commonly used treatment for advanced hepatocellular carcinoma (HCC), but still lacks accurate real-time biomarkers for monitoring its therapeutic efficacy. Here, we explored whether copy number profiling of circulating free DNA (cfDNA) could be utilized to predict responses and prognosis in HCC patients with TACE treatment. In total, 266 plasma cfDNA samples were collected from 64 HCC patients, 57 liver cirrhosis (LC) patients and 32 healthy volunteers. We performed low-depth whole-genome sequencing (LD-WGS) on cfDNA samples to conduct copy number variant (CNV) analysis and tumour fraction (TFx) quantification. Then, the correlation between TFx/CNVs and therapeutic efficacy, treatment outcomes and lipiodol deposition were explored. The change in TFx during TACE treatment was associated with patients' tumour burden, and could accurately and earlier predict treatment response and prognosis, providing an alternative strategy other than mRECIST. Meanwhile, the chromosomal 16q/NQO1 amplification indicated worse therapeutic response; in patients who underwent multiple TACE sessions, TFx change during their first TACE treatment reflected the long-term survival; additionally, the copy number amplification of chromosome 1q, 3p, 6p, 8q, 10p, 12q, 18p or 18q affected lipiodol deposition. Overall, we have provided a new liquid biopsy approach for future TACE management of HCC patients.

Caveolin-mediated cytosolic delivery of spike nanoparticle enhances antitumor immunity of neoantigen vaccine for hepatocellular carcinoma

Rationale: Although neoantigen-based cancer vaccines have shown promise in various solid tumors, limited immune responses and clinical outcomes have been reported in patients with advanced disease. Cytosolic transport of neoantigen and adjuvant is required for the activation of intracellular Toll-like receptors (TLRs) and cross-presentation to prime neoantigen-specific CD8+T cells but remains a significant challenge. Methods: In this study, we aimed to develop a virus-like silicon vaccine (V-scVLPs) with a unique spike topological structure, capable of efficiently co-delivering a hepatocellular carcinoma (HCC)-specific neoantigen and a TLR9 agonist to dendritic cells (DCs) to induce a robust CD8+T cell response to prevent orthotopic tumor growth. We evaluated the antitumor efficacy of V-scVLPs by examining tumor growth and survival time in animal models, as well as analyzing tumor-infiltrating CD8+T cells and cytokine responses in the tumor microenvironment (TME). To evaluate the synergistic efficacy of V-scVLPs in combination with α-TIM-3 in HCC, we used an orthotopic HCC mouse model, a lung metastasis model, and a tumor rechallenge model after hepatectomy. Results: We found that V-scVLPs can efficiently co-deliver the hepatocellular carcinoma (HCC)-specific neoantigen and the TLR9 agonist to DCs via caveolin-mediated endocytosis. This advanced delivery strategy results in efficient lymph node draining of V-scVLPs to activate lymphoid DC maturation for promoting robust CD8+T cells and central memory T cells responses, which effectively prevents orthotopic HCC tumor growth. However, in the established orthotopic liver tumor models, the inhibitory receptor of TIM-3 was significantly upregulated in tumor-infiltrating CD8+T cells after immunization with V-scVLPs. Blocking the TIM-3 signaling further restored the antitumor activity of V-scVLPs-induced CD8+T cells, reduced the proportion of regulatory T cells, and increased the levels of cytokines to alter the tumor microenvironment to efficiently suppress established orthotopic HCC tumor growth, and inhibit lung metastasis as well as recurrence after hepatectomy. Conclusion: Overall, the developed novel spike nanoparticles with efficient neoantigen and adjuvant intracellular delivery capability holds great promise for future clinical translation to improve HCC immunotherapy.

Metabolism-Related Gene Pairs to Predict the Clinical Outcome and Molecular Characteristics of Early Hepatocellular Carcinoma

Recurrence is the main factor affecting the prognosis of early hepatocellular carcinoma (HCC), which is not accurately evaluated by clinical indicators. The metabolic heterogeneity of HCC hints at the possibility of constructing a stratification model to predict the clinical outcome. On the basis of the relative expression orderings of 2939 metabolism-related genes, an individualized signature with 10 metabolism-related gene pairs (10-GPS) was developed from 250 early HCC samples in the discovery datasets, which stratified HCC patients into the high- and low-risk subgroups with significantly different survival rates. The 10-GPS was validated in 311 public transcriptomic samples from two independent validation datasets. A nomogram that included the 10-GPS, age, gender, and stage was constructed for eventual clinical evaluation. The low-risk group was characterized by lower proliferation, higher metabolism, increased activated immune microenvironment, and lower TIDE scores, suggesting a better response to immunotherapy. The high-risk group displayed hypomethylation, higher copy number alterations, mutations, and more overexpression of immune-checkpoint genes, which might jointly lead to poor outcomes. The prognostic accuracy of the 10-GPS was further validated in 47 institutional transcriptomic samples and 101 public proteomic samples. In conclusion, the 10-GPS is a robust predictor of the clinical outcome for early HCC patients and could help evaluate prognosis and characterize molecular heterogeneity.

Identification of tumor mutations in plasma based on mutation variant frequency change (MVFC)

To overcome the dependency of strategies utilizing cell-free DNA (cfDNA) on tissue sampling, the emergence of sequencing panels for non-invasive mutation screening was promoted. However, cfDNA sequencing with panels still suffers from either inaccuracy or omission, and novel approaches for accurately screening tumor mutations solely based on plasma without gene panel restriction are urgently needed. We performed unique molecular identifier (UMI) target sequencing on plasma samples and peripheral blood mononuclear cells (PBMCs) from 85 hepatocellular carcinoma (HCC) patients receiving surgical resection, which were divided into an exploration dataset (20 patients) or an evaluation dataset (65 patients). Plasma mutations were identified in pre-operative plasma, and the mutation variant frequency change (MVFC) between post- and pre-operative plasma was then calculated. In the exploration dataset, we observed that plasma mutations with MVFC < 0.2 were enriched for tumor mutations identified in tumor tissues and had frequency changes that correlated with tumor burden; these plasma mutations were therefore defined as MVFC-identified tumor mutations. The presence of MVFC-identified tumor mutations after surgery was related to shorter relapse-free survival (RFS) in both datasets and thus indicated minimum residual disease (MRD). The combination of MVFC-identified tumor mutations and Alpha Fetoprotein (AFP) could further improve MRD detection (P < 0.0001). Identification of tumor mutations based on MVFC was also confirmed to be applicable with a different gene panel. Overall, we proposed a novel strategy for non-invasive tumor mutation screening using solely plasma that could be utilized in HCC tumor-burden monitoring and MRD detection.

Personalized neoantigen hydrogel vaccine combined with PD-1 and CTLA-4 double blockade elicits antitumor response in liver metastases by activating intratumoral CD8+CD69+ T cells

BACKGROUND

Liver metastasis is highly aggressive and immune tolerant, and lacks effective treatment strategies. This study aimed to develop a neoantigen hydrogel vaccine (NPT-gels) with high clinical feasibility and further investigate its efficacy and antitumor molecular mechanisms in combination with immune checkpoint inhibitors (ICIs) for the treatment of liver metastases.

METHODS

The effects of liver metastasis on survival and intratumor T-cell subpopulation infiltration in patients with advanced tumors were investigated using the Surveillance, Epidemiology, and End Results Program (SEER) database and immunofluorescence staining, respectively. NPT-gels were prepared using hyaluronic acid, screened neoantigen peptides, and dual clinical adjuvants [Poly(I:C) and thymosin α-1]. Then, the efficacy and corresponding antitumor molecular mechanisms of NPT-gels combined with programmed death receptor 1 and cytotoxic T-lymphocyte-associated protein 4 double blockade (PCDB) for the treatment of liver metastases were investigated using various preclinical liver metastasis models.

RESULTS

Liver metastases are associated with poorer 5-year overall survival, characterized by low infiltration of cytotoxic CD8+ T cells and high infiltration of regulatory T cells (Tregs). NPT-gels overcame the challenges faced by conventional neoantigen peptide vaccines by sustaining a durable, high-intensity immune response with a single injection and significantly improving the infiltration of neoantigen-specific T-cell subpopulations in different mice subcutaneous tumor models. Importantly, NPT-gels further combined with PCDB could enhance neoantigen-specific T-cell infiltration and effectively unlock the immunosuppressive microenvironment of liver metastases, showing superior antitumor efficacy and inducing long-term immune memory in various preclinical liver metastasis models without obvious toxicity. Mechanistically, the combined strategy can inhibit Tregs, induce the production and infiltration of neoantigen-specific CD8+CD69+ T cells to enhance the immune response, and potentially elicit antigen-presenting effects in Naïve B_Ighd+ cells and M1-type macrophages.

CONCLUSIONS

This study demonstrated that NPT-gels combined with PCDB could exert a durable and powerful antitumor immunity by enhancing the recruitment and activation of CD8+CD69+ T cells, which supports the rationale and clinical translation of this combination strategy and provides important evidence for further improving the immunotherapy efficacy of liver metastases in the future.

Two-plex in vivo molecular imaging in the second near-infrared window for immunotherapeutic response

Tumor-infiltrating CD8+ T cells and programmed death-1 (PD1) levels are critical indicators for tumor immunophenotyping and therapeutic decision-making. Noninvasive optical imaging in the second near infrared window (NIR-II) is particularly well-suited for investigating the biological processes within tumors in live mammals, thanks to its deep-tissue penetration and superior spatiotemporal resolution. However, in vivo NIR-II imaging has primarily been restricted to a single probe at a time. Methods: Herein, we developed a two-plex NIR-II molecular imaging method utilizing the non-overlapping fluorescence emission of indocyanine green (ICG) in the NIR-IIa window (1000-1200 nm) and PbS/CdS core-shell quantum dots (QDs) in the NIR-IIb window (1500-1700 nm). By integrating PD1 aptamer-labeled ICG (ICG-Apt-PD1, targeting PD1) and CD8 aptamer-labeled QDs (QDs@Apt-CD8, targeting CD8+ T cells), our two-plex NIR-II molecular imaging enabled simultaneous and noninvasive monitoring of the number of CD8+ T cells and PD1 levels in tumors. Results: QDs@Apt-CD8 demonstrated the excellent ability for in vivo imaging of tumor infiltrating CD8+ T cells, owing to its strong NIR-IIb luminescence and the high selectivity and specificity. This two-plex in vivo molecular imaging allowed for dynamic monitoring for PD1 levels and the number of CD8+ T cells in tumors. We observed the heterogeneous bio-distributions of PD1 and CD8+ T cells across different tumor types and revealed the tumor immunophenotypes. Moreover, our findings indicated that the low PD1 and high CD8+ T cells levels in tumors predicted a better anti-tumor effect. Conclusions: Such in vivo noninvasive NIR-II molecular imaging would complement ex vivo biopsy-based diagnostic techniques, and it could contribute to developing an in vivo tumor immune-scoring algorithm to offer a more precise prediction for immunotherapeutic response.

In Situ Formation of Hydrogel Wound Dressing Based on Carboxymethyl Chitin/Tannic Acid for Promoting Skin Wound Healing

Triggering the healing process of drug-resistant bacteria-infected wounds has attracted great attention due to global morbidity that may induce gangrene, amputation, and even death. Here, a chitin derivative, carboxymethyl chitosan (CMC), tannic acid (TA), and Cu2+ were used for hydrogel engineering. Using sodium bicarbonate as the neutralizer and reductant, hydrogen bonds between CMC and TA and in situ Cu(OH)2 generation via ion coordination force between Cu2+ and TA facilitated the synthesis of CMC/TA/Cu hydrogel. Cu2+ and TA release, cytotoxicity, in vitro cell migration, angiogenesis, and antidrug-resistant bacteria were measured. Besides, wound closure was evaluated in vivo using the methicillin-resistant Staphylococcus aureus (MRSA)-infected excisional dermal wound mouse model. Negligible toxicity was observed both in vitro and in vivo. Dermal cell migration and angiogenesis were significantly enhanced. In vivo, the CMC/TA/Cu hydrogel induced effective re-epithelialization, collagen deposition, inflammatory alleviation, and MRSA inhibition during wound repair in mice. All these results confirmed that the CMC/TA/Cu hydrogel is a promising novel dressing for chronic wound healing in clinic.

Dysregulation of global circular RNA abundance regulated by spliceosomes predicts prognosis in hepatocellular carcinoma

CircRNAs have been reported to play crucial roles in tumor progression and recurrence, showing potential as biomarkers in cancer. However, the global abundance of circRNA and their involvement in hepatocellular carcinoma (HCC) development have not been fully explored. Whole transcriptome sequencing was performed on tumor and peritumor from 60 patients with HCC to quantify the expression of circRNAs, and the global circRNA abundance was calculated by circRNA index (CRI). Gene-set enrichment analysis and weighted gene co-expression network analysis were used to reveal the biological signaling pathways associated with the global circRNA abundance. The correlation between the global circRNA abundance and the infiltration level of CD8+ T cells was explored by immunohistochemical assays. Small interfering RNA was used to knock down the pre-messenger RNA spliceosome in HCC cell lines to verify the regulation of spliceosome in global circRNA abundance. We found that dysregulation of global circRNA abundance in both tumor and peritumor could lead to worse prognosis. The immunohistochemical assay further revealed that the dysregulation of global circRNA abundance in both tumor and peritumor would obstruct the CD8+ T cells from invading into the tumor, which might explain its correlation with HCC prognosis. We also demonstrated that the spliceosome genes were the main factors to regulate the global circRNA abundance in HCC, and these results were also confirmed by knockdown experiments. Conclusion: This study revealed the association between the global circRNA abundance and patients' prognosis and its underlying mechanism.

Multifunctional Biomimetic Nanocarriers for Dual-Targeted Immuno-Gene Therapy Against Hepatocellular Carcinoma

Growing evidences have proved that tumors evade recognition and attack by the immune system through immune escape mechanisms, and PDL1/Pbrm1 genes have a strong correlation with poor response or resistance to immune checkpoint blockade (ICB) therapy. Herein, a multifunctional biomimetic nanocarrier (siRNA-CaP@PD1-NVs) is developed, which can not only enhance the cytotoxic activity of immune cells by blocking PD1/PDL1 axis, but also reduce tumor immune escape via Pbrm1/PDL1 gene silencing, leading to a significant improvement in tumor immunosuppressive microenvironment. Consequently, the nanocarrier promotes DC cell maturation, enhances the infiltration and activity of CD8+ T cells, and forms long-term immune memory, which can effectively inhibit tumor growth or even eliminate tumors, and prevent tumor recurrence and metastasis. Overall, this study presents a powerful strategy for co-delivery of siRNA drugs, immune adjuvant, and immune checkpoint inhibitors, and holds great promise for improving the effectiveness and safety of current immunotherapy regimens.

Targeting Antigen-Presenting Cells to Enhance the Tumor-Spleen Immunity Cycle through Liposome-Neoantigen Vaccine

Effective immune responses in both the spleen and the tumor microenvironment are crucial for cancer immunotherapy. However, delivery of neoantigen peptide vaccines to antigen-presenting cells (APCs) at these sites remains challenging. In this study, LNPsD18, a cationic liposomal formulation that targets and enhances APC uptake at both sites without modifying the targeting ligands is developed. By co-delivering tumor-specific neoantigens and a cholesterol-coupled toll-like receptor 9 (TLR9) agonist within LNP-vaxD18, an approximately 60-fold increase in dendritic cell uptake compared to neoantigen-adjuvant mixtures is achieved. Intravenous administration of the liposome-neoantigen peptide vaccine targets both the spleen and the tumor, boosting splenic DC activation, increasing M1-type tumor-associated macrophages, and elevating tumor cytokine levels. This reshapes the tumor microenvironment, enhancing IFN-γ-producing CD8+ T cells and TCF1+CD8+ T cells within tumors. These outcomes significantly inhibit established tumor growth compared to nontargeted lipid-based nanovaccine formulations, resulting in improved survival in orthotopic hepatocellular carcinoma and colorectal cancer models. The findings highlight the importance of targeting APCs in both the spleen and tumors to optimize the therapeutic efficacy of liposome-neoantigen vaccines in cancer treatment.

Targeting Mesothelin Enhances Personalized Neoantigen Vaccine Induced Antitumor Immune Response in Orthotopic Pancreatic Cancer Mouse Models

The immunosuppressive microenvironment in pancreatic cancer, characterized by low tumor-specific T cells and excessive fibrosis, limits the effectiveness of immunotherapy. Here, three datasets and multi-immunofluorescence staining of tissue microarrays in pancreatic cancer indicate that mesothelin (MSLN) expression negatively correlates with cytotoxic T cells in tumor. Anti-MSLN antibody (αMSLN) treatment of pancreatic cancer in vivo can significantly increase T cell infiltration. Meanwhile, the combination of αMSLN and neoantigen peptide vaccine identified from pancreatic cancer cell lines is demonstrated to be more effective in inducing neoantigen-specific T cell generation and infiltration at subcutaneous and orthotopic pancreatic cancer models for enhancing antitumor efficacy. Single-cell transcriptome analysis shows that the combined treatment significantly reduces the proportion of fibroblasts, improves the infiltration of IFN-γ+CD4+ and GZMK+CD8+ T cells, as well as reduces the interaction of antigen presentation-associated ligands and receptors between antigen-presenting Cancer-Associated Fibroblasts (apCAFs) and naive CD4+ T cells. The negative correlations between apCAFs and CD8+ T cells/IFN-γ+CD4+ T cells are further confirmed in human pancreatic cancer tissues. Overall, this study demonstrates that targeting MSLN can improve neoantigen vaccine induced immune efficacy by reducing apCAFs to interrupt the conversion of naive CD4+ T cells to Tregs, and therefore increase the infiltration of tumor-specific T cells.