Tumor Microenvironment Cascade-Responsive Nanodrug with Self-Targeting Activation and ROS Regeneration for Synergistic Oxidation-Chemotherapy

Carrier-free nanodrug with exceptionally high drug payload has attracted increasing attentions. Herein, we construct a pH/ROS cascade-responsive nanodrug which could achieve tumor acidity-triggered targeting activation followed by circularly amplified ROS-triggered drug release via positive-feedback loop. The di-selenide-bridged prodrug synthesized from vitamin E succinate and methotrexate (MTX) self-assembles into nanoparticles (VSeM); decorating acidity-cleavable PEG onto VSeM surface temporarily shields the targeting ability of MTX to evade immune clearance and consequently elongate circulation time. Upon reaching tumor sites, acidity-triggered detachment of PEG results in targeting recovery to enhance tumor cell uptake. Afterward, the VSeM could be dissociated in response to intracellular ROS to trigger VES/MTX release; then the released VES could produce extra ROS to accelerate the collapse of VSeM. Finally, the excessive ROS produced from VES could synergize with the released MTX to efficiently suppress tumor growth via orchestrated oxidation-chemotherapy. Our study provides a novel strategy to engineer cascade-responsive nanodrug for synergistic cancer treatment.

Mesenchymal stromal cell therapies: immunomodulatory properties and clinical progress

Mesenchymal stromal cells (MSCs) are a subset of heterogeneous non-hematopoietic fibroblast-like cells that can differentiate into cells of multiple lineages, such as chondrocytes, osteoblasts, adipocytes, myoblasts, and others. These multipotent MSCs can be found in nearly all tissues but mostly located in perivascular niches, playing a significant role in tissue repair and regeneration. Additionally, MSCs interact with immune cells both in innate and adaptive immune systems, modulating immune responses and enabling immunosuppression and tolerance induction. Understanding the biology of MSCs and their roles in clinical treatment is crucial for developing MSC-based cellular therapy for a variety of pathological conditions. Here, we review the progress in the study on the mechanisms underlying the immunomodulatory and regenerative effects of MSCs; update the medical translation of MSCs, focusing on the registration trials leading to regulatory approvals; and discuss how to improve therapeutic efficacy and safety of MSC applications for future.

Ultrasound-Driven Biomimetic Nanosystem Suppresses Tumor Growth and Metastasis through Sonodynamic Therapy, CO Therapy, and Indoleamine 2,3-Dioxygenase Inhibition

The rational design of nanoplatforms to bypass reticuloendothelial system (RES) clearance, enhance spatiotemporal controllability, and boost host immune responses to achieve synergized tumor-targeted therapeutic purpose is highly desired. Herein, a biomimetic nanosystem is developed for tumor-targeted in situ delivery of singlet oxygen (¹O₂) and carbon monoxide (CO) in response to exogenous stimulus ultrasound (US) and endogenous stimulus hydrogen peroxide (H₂O₂) in tumor microenvironment, respectively. Taking advantages of tumor homing and RES evasion abilities of the macrophage membrane coating, our designed nanosystem shows excellent accumulation at the tumor site and effective suppression of tumor growth through US/H₂O₂-generated ¹O₂ and CO to induce cell apoptosis and mitochondrial dysfunction. Furthermore, our nanosystem can induce significant tumor immunogenic death by ¹O₂/CO therapy, then can achieve effective immune responses and long-term immune memory through the combination of indoleamin 2,3-dioxygenase (IDO) signal blocking to effectively against tumor rechallenge and prevent lung metastasis. Taken together, the here-presented therapeutic strategy based on sonodynamic/CO therapy and IDO signaling inhibition might provide a promising perspective for synergistically treating cancer in future clinical translations.

Converting Immune Cold into Hot by Biosynthetic Functional Vesicles to Boost Systematic Antitumor Immunity

Immune cold tumor characterized by low immunogenicity, insufficient and exhausted tumor-infiltrating lymphocytes, and immunosuppressive microenvironment is the main bottleneck responsible for low patient response rate of immune checkpoint blockade. Here, we developed biosynthetic functional vesicles (BFVs) to convert immune cold into hot through overcoming hypoxia, inducing immunogenic cell death, and immune checkpoint inhibition. The BFVs present PD1 and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on the surface, whereas load catalase into their inner core. The TRAIL can specifically induce immunogenic death of cancer cells to initiate immune response, which is further synergistically strengthened by blocking PD1/PDL1 checkpoint signal through ectogenic PD1 proteins on BFVs. The catalase can produce O₂ to overcome tumor hypoxia, in turn to increase infiltration of effector T cells while deplete immunosuppressive cells in tumor. The BFVs elicit robust and systematic antitumor immunity, as demonstrated by significant regression of tumor growth, prevention of abscopal tumors, and excellent inhibition of lung metastasis.

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BFVs integrated PD1, TRAIL, and Catalase to convert immune cold tumor into hot

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TRAIL induces cancer cell immunogenic death, ectogenic PD1 blocks checkpoint signal

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Catalase reduces TME hypoxia to enhance effector T cell infiltration and activation

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BFVs boost systematic antitumor immunity and achieve long-term immune memory

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.

Antioxidant preconditioning improves therapeutic outcomes of adipose tissue-derived mesenchymal stem cells through enhancing intrahepatic engraftment efficiency in a mouse liver fibrosis model

BACKGROUND

Although it has been preclinically suggested that adipose tissue-derived mesenchymal stem cell (ADSC)-based therapy could effectively treat chronic liver diseases, the hepatic engraftment of ADSCs is still extremely low, which severely limits their long-term efficacy for chronic liver diseases. This study was designed to investigate the impact of antioxidant preconditioning on hepatic engraftment efficiency and therapeutic outcomes of ADSC transplantation in liver fibrotic mice.

METHODS

Liver fibrosis model was established by using intraperitoneal injection of carbon tetrachloride (CCl₄) in the male C57BL/6 mice. Subsequently, the ADSCs with or without antioxidant pretreatment (including melatonin and reduced glutathione (GSH)) were administrated into fibrotic mice via tail vein injection. Afterwards, the ADSC transplantation efficiency was analyzed by ex vivo imaging, and the liver functions were assessed by biochemical analysis and histopathological examination, respectively. Additionally, a typical hydrogen peroxide (H₂O₂)-induced cell injury model was applied to mimic the cell oxidative injury to further investigate the protective effects of antioxidant preconditioning on cell migration, proliferation, and apoptosis of ADSCs.

RESULTS

Our data showed that antioxidant preconditioning could enhance the therapeutic effects of ADSCs on liver function recovery by reducing the level of AST, ALT, and TBIL, as well as the content of hepatic hydroxyproline and fibrotic area in liver tissues. Particularly, we also found that antioxidant preconditioning could enhance hepatic engraftment efficiency of ADSCs in liver fibrosis model through inhibiting oxidative injury.

CONCLUSIONS

Antioxidant preconditioning could effectively improve therapeutic effects of ADSC transplantation for liver fibrosis through enhancing intrahepatic engraftment efficiency by reducing oxidative injuries. These findings might provide a practical strategy for enhancing ADSC transplantation and therapeutic efficiency.

RBC Membrane Camouflaged Semiconducting Polymer Nanoparticles for Near-Infrared Photoacoustic Imaging and Photothermal Therapy

Semiconducting conjugated polymer nanoparticles (SPNs) represent an emerging class of phototheranostic materials with great promise for cancer treatment. In this report, low-bandgap electron donor-acceptor (D-A)-conjugated SPNs with surface cloaked by red blood cell membrane (RBCM) are developed for highly effective photoacoustic imaging and photothermal therapy. The resulting RBCM-coated SPN (SPN@RBCM) displays remarkable near-infrared light absorption and good photostability, as well as high photothermal conversion efficiency for photoacoustic imaging and photothermal therapy. Particularly, due to the small size (< 5 nm), SPN@RBCM has the advantages of deep tumor penetration and rapid clearance from the body with no appreciable toxicity. The RBCM endows the SPNs with prolonged systematic circulation time, less reticuloendothelial system uptake and reduced immune-recognition, hence improving tumor accumulation after intravenous injection, which provides strong photoacoustic signals and exerts excellent photothermal therapeutic effects. Thus, this work provides a valuable paradigm for safe and highly efficient tumor photoacoustic imaging and photothermal therapy for further clinical translation.

Tumor microenvironment-activated self-recognizing nanodrug through directly tailored assembly of small-molecules for targeted synergistic chemotherapy

Carrier-free nanodrug via small-molecule assembly is a promising alternative strategy for tumor therapy. Thus, developing a self-recognizing carrier-free nanodrug without introduction of foreign ligand is very attractive to meet both targeting and therapeutic requirements while reducing structural complexity. Here we fabricated a tumor microenvironment-activated self-targeting nanodrug, via co-assembly of hydroxycamptothecin (HCPT) and bi-functional methotrexate (MTX, not only has antitumor effect but also shows innate affinity towards folate receptors) followed by surface covering through acidity-responsive polyethylene glycol (PEG). Notably, the morphology and size of MTX-HCPT nanodrug could be tuned by varying the drug-to-drug ratio and assembly time. The PEG shell of our nanodrug could be detached in response to acidic tumor microenvironment, and then MTX could be exposed for self-targeting to enhance tumor cell uptake. Subsequently, the shell-detached nanodrug could be dissociated in relatively stronger acidic lysosomal environment, resulting in burst release of both drugs. Further in vitro and in vivo studies demonstrated that our nanodrug showed a ~2.98-fold increase in cancer cell uptake, a ~1.25-fold increase in drug accumulation at tumor site, a significantly lower CI₅₀ value of ~0.3, a ~27.3% improvement in tumor inhibition comparing with the corresponding non-responsive nanodrug. Taken together, the here reported tumor microenvironment-activated self-recognizing nanodrug might be an extremely promising strategy for synergistically enhancing chemotherapy efficiency with minimized side effects.

Photodynamic Therapy Combined with Antihypoxic Signaling and CpG Adjuvant as an In Situ Tumor Vaccine Based on Metal-Organic Framework Nanoparticles to Boost Cancer Immunotherapy

Photodynamic therapy (PDT) usually aggravates tumor hypoxia, which promotes the survival and metastasis of residue cancer cells; furthermore, although PDT-induced immunogenic death of cancer cells can induce host antitumor responses, such responses are generally weak and not enough to eliminate the residue cancer cells. Here, metal-organic framework (MOF)-based nanoparticles to combine PDT, antihypoxic signaling, and CpG adjuvant as an in situ tumor vaccine to boost host anticancer responses after PDT are designed. The MOF-based nanoparticles are self-assembled from H₂ TCPP and zirconium ions with hypoxia inducible factor (HIF) signaling inhibitor (ACF) and immunologic adjuvant (CpG) loading, and hyaluronic acid (HA) coating on the surface. The final nanoparticles (PCN-ACF-CpG@HA) can specifically target cancer cells overexpressing CD44 receptor though HA; the aggravated hypoxic survival signaling after PDT can be blocked by ACF to inhibit the HIF-1α induced survival and metastasis. With the help of CpG adjuvant, the tumor associated antigens generated from PDT-based cancer cell destruction can initiate strong antitumor immune responses to eliminate residue cancer cells. Taken together, a novel in situ immunostimulatory strategy is designed to synergistically enhance therapeutic effects of PDT by activating host antitumor immune-responses both in vitro and in vivo, which may have great potential for clinical translation in future.

Rapid and highly sensitive quantification of the anti-tuberculosis agents isoniazid, ethambutol, pyrazinamide, rifampicin and rifabutin in human plasma by UPLC-MS/MS

With the increased cases of multidrug- or rifampicin-resistant tuberculosis and co-infection with HIV globally, it is difficult to achieve ideal clinical responses because of poor drug absorption and drug-drug interactions. Herein, a bioanalytical UPLC-MS/MS method was developed and validated to quantify five anti-TB agents in human plasma samples for detecting blood drug concentrations to improve therapeutic effects. To overcome the matrix effects, stable isotope labeled analogue of each analyte was used for internal standardization. A simple single-step protein precipitation by acetonitrile was employed for the sample preparation, then the analytes including rifampicin, rifabutin, pyrazinamid, ethambutol, isoniazid and their isotope labeled internal standards (ILISs) were implemented on an HILIC silica column with a gradient mode. The linear range for each analyte was covering the peak drug concentration (C_max) in the 20 times diluted plasma samples. The coefficient of variation of intra- and inter-day precision was less than 17.0 %, and the accuracy ranged between 91.5 and 110.0 %. The extraction recoveries of all agents were ≥90.2 %, and the matrix effects with internal standard-normalization for all agents were 97.1-110.0 %. The optimal blood sampling time was designed basing on the results of stability validation. This UPLC-MS/MS method with a run time of 3.5 min was successfully applied to routine therapeutic monitoring of the five anti-TB agents in patient plasma.

Ku80 negatively regulates the expression of OCT4 via competitive binding to SALL4 and promoting lysosomal degradation of OCT4

SALL4 and OCT4, along with other pluripotency-associated transcription factors, play critical roles in maintaining embryonic stem cell pluripotency and self-renewal. Ku80 is a component of the protein complex called DNA-dependent protein kinase, which mainly involved in DNA double-strand break repair. In this study, we show evidence that Ku80 physically interacted with SALL4. The interaction competitively disrupts the SALL4-OCT4 complex and result in OCT4 lysosomal degradation. Finally, Ku80 inhibits self-renewal and metastasis of hepatocellular carcinoma cells through breaking the SALL4-OCT4 interactions and down-regulating the expression of OCT4. Our study reveal novel function of Ku80 in stemness maintaining of cancer stem cells via its interaction with SALL4 and highlight the double-sidedness of Ku80 as an anti-cancer target.

MT1G serves as a tumor suppressor in hepatocellular carcinoma by interacting with p53

Poor prognosis of hepatocellular carcinoma (HCC) patients is frequently associated with rapid tumor growth, recurrence and drug resistance. MT1G is a low-molecular weight protein with high affinity for zinc ions. In the present study, we investigated the expression of MT1G, analyzed clinical significance of MT1G, and we observed the effects of MT1G overexpression on proliferation and apoptosis of HCC cell lines in vitro and in vivo. Our results revealed that MT1G was significantly downregulated in tumor tissues, and could inhibit the proliferation as well as enhance the apoptosis of HCC cells. The mechanism study suggested that MT1G increased the stability of p53 by inhibiting the expression of its ubiquitination factor, MDM2. Furthermore, MT1G also could enhance the transcriptional activity of p53 through direct interacting with p53 and providing appropriate zinc ions to p53. The modulation of MT1G on p53 resulted in upregulation of p21 and Bax, which leads cell cycle arrest and apoptosis, respectively. Our in vivo assay further confirmed that MT1G could suppress HCC tumor growth in nude mice. Overall, this is the first report on the interaction between MT1G and p53, and adequately uncover a new HCC suppressor which might have therapeutic values by diminishing the aggressiveness of HCC cells.

Antioxidants inhibit cell senescence and preserve stemness of adipose tissue-derived stem cells by reducing ROS generation during long-term in vitro expansion

BACKGROUND

Adipose tissue-derived mesenchymal stem cells (ADSCs) are promising candidates for regenerative medicine. However, long-term in vitro passaging leads to stemness loss and cell senescence of ADSCs, resulting in failure of ADSC-based therapy.

METHODS

In this study, ADSCs were treated with low dose of antioxidants (reduced glutathione and melatonin) with anti-aging and stem cell protection properties in the in vitro passaging, and the cell functions including stem cell senescence, cell migration, cell multidirectional differentiation potential, and ROS content were carefully analyzed.

RESULTS

We found that GSH and melatonin could maintain ADSC cell functions through reducing cell senescence and promoting cell migration, as well as by preserving stemness and multidirectional differentiation potential, through inhibiting ROS generation during long-term expansion of ADSCs.

CONCLUSIONS

Our results suggested that antioxidant treatment could efficiently prevent the dysfunction and preserve cell functions of ADSCs after long-term passaging, providing a practical strategy to facilitate ADSC-based therapy.

Inflammatory Micro-environment Contributes to Stemness Properties and Metastatic Potential of HCC via the NF-κB/miR-497/SALL4 Axis

Increasing evidence has demonstrated the essential role of inflammatory micro-environment in tumorigenesis and tumor progression. Some cancer cells in tumor maintain typical stemness properties and, with the capacity of self-renewal, are thought to be crucial for the initiation and maintenance of tumors as well as their metastasis. Although both inflammatory micro-environment and stemness properties played crucial roles in tumor initiation and development, currently it is still unclear whether and how the inflammatory micro-environment promotes cancer stemness properties. Here, we show the first evidence that the inflammatory micro-environment promotes the stemness properties and metastatic potential of hepatocellular carcinoma (HCC) via the NF-κB/miR-497/SALL4 axis. We discover that miR-497 directly targets SALL4, negatively regulates its expression, and further inhibits the self-renewal and metastasis of HCC; more importantly, inflammatory factor TNF-α inhibits the expression of miR-497 via NF-kB-mediated negative transcriptional regulation and simultaneously upregulates the expression of SALL4 and promotes the self-renewal and metastasis phenotypes of HCC cells. Moreover, lower expression of miR-497 is significantly associated with poor prognosis in HCC patients. Taken together, our findings not only revealed a novel signaling pathway (NF-κB/miR-497/SALL4 axis) to connect inflammation with stemness properties, and clarified the molecular mechanisms underlying the inflammation-mediated self-renewal and metastasis phenotypes, but also provided novel molecular targets for developing new anticancer strategies.

Comprehensive Liquid Profiling of Circulating Tumor DNA and Protein Biomarkers in Long-Term Follow-Up Patients with Hepatocellular Carcinoma

PURPOSE

Circulating tumor DNA (ctDNA) provides a novel approach for detecting tumor burden and predicting clinical outcomes of hepatocellular carcinoma (HCC). Here, we performed a thorough evaluation of HCC circulating genetic features and further fully integrated them to build a robust strategy for HCC monitoring and prognostic outcome assessment.

EXPERIMENTAL DESIGN

We performed target sequencing and low-coverage whole-genome sequencing on plasma samples collected from 34 long-term follow-up patients with HCC to capture tumor somatic SNVs and CNVs, respectively. Clinical information was also obtained to evaluate the prognostic performance of ctDNA comparing with clinically applied protein biomarkers.

RESULTS

All plasma samples before surgery showed somatic genetic variations resembling corresponding tumor tissues. During follow-up, SNVs and CNVs dynamically changed correlating to patients' tumor burden. We integrated the comprehensive ctDNA mutation profiles to provide a robust strategy to accurately assess patients' tumor burden with high consistence comparing with imaging results. This strategy could discover tumor occurrence in advance of imaging for an average of 4.6 months, and showed superior performance than serum biomarkers AFP, AFP-L3%, and Des-Gamma-Carboxy Prothrombin (DCP). Furthermore, our strategy could precisely detect minimal residual disease (MRD) in advance and predict patients' prognostic outcomes for both relapse-free survival (P = 0.001) and overall survival (P = 0.001); further combining ctDNA with DCP could increase the sensitivity for MRD detection.

CONCLUSIONS

We demonstrated that plasma CNV and SNV levels dynamically correlated with patients' tumor burden in HCC. Our strategy of comprehensive mutation profile integration could accurately and better evaluate patients' prognostic risk and detect tumor occurrence in advance than traditional strategies.

An Optogenetic Controllable T Cell System for Hepatocellular Carcinoma Immunotherapy

Rationale: T-cell based immunotherapy increasingly shows broad application prospects in cancer treatment, but its performance in solid tumors is far from our expectation, partly due to the re-inhibition of infiltrated T cells by immunosuppressive tumor microenvironment. Here we presented an artificial synthetic optogenetic circuit to control the immune responses of engineered T cells on demand for promoting and enhancing the therapeutic efficiency of cancer immunotherapy. Methods: We designed and synthesized blue-light inducible artificial immune signaling circuit and transgene expression system. The blue light triggered transgene expression was investigated by luciferase activity assay, qPCR and ELISA. The in vitro cytotoxicity and proliferation assays were carried out on engineered T cells. The in vivo anti-tumor activity of engineered T cells was investigated on xenograft model of human hepatocellular carcinoma. Results: Blue light stimulation could spatiotemporally control gene expression of specific cytokines (IL2, IL15, and TNF-α) in both engineered 293T cells and human primary T cells. This optogenetic engineering strategy significantly enhanced the expansion ability and cytolytic activity of primary T cells upon light irradiation, and the light activated T cells showed high-efficiency of elimination against xenograft of hepatocellular carcinoma cells. Conclusions: The current study represented an engineered remotely control T cell system for solid tumor treatment, and provided a potential strategy to partially overcome the intrinsic shortages of current immune cell therapy.

Circular RNA profiling identifies circADAMTS13 as a miR-484 sponge which suppresses cell proliferation in hepatocellular carcinoma

Circular RNA (circRNA) can participate in various biological processes, including tumorigenesis, through their microRNA response elements. Alterations in circRNA profiles during hepatocellular carcinoma (HCC) progression and their clinical significance remain unclear. Here, we present extensive analysis of circRNA profiles in tumor and matched peritumor tissues collected from 10 HCC patients, conducted to identify circRNA related to HCC progression. A total of 42 dysregulated circRNA (38 down‐regulated and 4 up‐regulated) were identified in HCC tumor tissues compared with matched peritumor tissues, revealing the heterogeneity of circRNA profiles in HCC. CircADAMTS13, derived from Exon 13–14 of the ADAMTS13 gene, was significantly downregulated in HCC tumor tissues. Furthermore, clinicopathological analysis revealed that up‐regulation of circADAMTS13 was negatively associated with tumor size but positively associated with prognosis. In addition, overexpression of circADAMTS13 could markedly inhibit HCC cell proliferation in vitro. Bioinformatic analysis and luciferase reporter assays further revealed that circADAMTS13 directly interacts with microRNA (miR)‐484. Rescue experiments showed that miR‐484 mimics can reverse the tumor‐suppressing roles of circADAMTS13 in HCC. Therefore, our results demonstrated that circADAMTS13 can serve as a tumor suppressor during HCC progression via the functional pathway of sponging miR‐484.

Fabrication of Red Blood Cell-Based Multimodal Theranostic Probes for Second Near-Infrared Window Fluorescence Imaging-Guided Tumor Surgery and Photodynamic Therapy

The therapeutic efficacy of fluorescence image-guided tumor surgery and photodynamic therapy (PDT) is impaired by the penetration depth limitation, low signal-to-noise ratio of traditional first near-infrared window (NIR I) fluorescence and the hypoxic tumor microenvironment. Here, a "red blood cell-based multimodal probe" was proposed to achieve enhanced tumor targeting and retention of fluorescent probes after an intravenous injection, so that second near-infrared window (NIR II) fluorescence bioimaging-guided complete tumor resection and high-efficiency photodynamic therapy could then be realized. Methods: The hexanoic acid ester-modified rose bengal (RB-HA), RGD (Arginine-Glycine-Aspartic) peptide and avidin were covalently coupled onto amine-modified upconversion nanoparticles (UCNPs) via EDC/NHS reaction (UCNPs@RB@RGD@avidin). Afterwards, the complex of ICG with bovine serum albumin (BSA) was loaded into RBCs through hypotonic dialysis (RBC@ICG). Then, the membrane proteins of RBC@ICG were biotinylated by biotin-modified phospholipids (RBC@ICG@biotin). Finally, the RBCp (Red Blood Cell based probe) was obtained by crosslinking UCNPs@RB@RGD@avidin to RBC@ICG@biotin through the interaction of avidin and biotin. The obtained multimodal RBCp was extensively characterized, both in vitro and in vivo, including analysis of chemical, physical and fluorescent features, O2 delivery ability, tumor accumulation, NIR II fluorescence bioimaging ability, photodynamic therapeutic efficiency, and biosafety. Results: The RBCp experienced efficient tumor targeting and long tumor retention for almost 4 h after intravenous injection, and the superior signal-to-noise ratio at the optimal time window can be used for guiding precise tumor resection under an 808-nm laser irradiation to facilitate lymph popliteal metastasis surgical delineation. Meanwhile, the RBCp can provide laser-responsive O2 release to enhance the PDT efficiency of popliteal lymph node metastasis under NIR II fluorescence bioimaging guidance. These excellent performances obviously lead to remarkably enhanced synergistic therapeutic effects of tumor surgery and metastatic inhibition. Conclusion: The proposed strategy will develop a new platform to increase surgical resection completeness and improve PDT efficiency, resulting in the successful and complete inhibition of tumor and metastasis, which could offer a promising approach for the clinical translation of malignant tumor treatment.

Self-Luminescing Theranostic Nanoreactors with Intraparticle Relayed Energy Transfer for Tumor Microenvironment Activated Imaging and Photodynamic Therapy

The low tissue penetration depth of external excitation light severely hinders the sensitivity of fluorescence imaging (FL) and the efficacy of photodynamic therapy (PDT) in vivo; thus, rational theranostic platforms that overcome the light penetration depth limit are urgently needed. To overcome this crucial problem, we designed a self-luminescing nanosystem (denoted POCL) with near-infrared (NIR) light emission and singlet oxygen (¹O₂) generation abilities utilizing an intraparticle relayed resonance energy transfer strategy.

Methods: Bis[3,4,6-trichloro-2-(pentyloxycarbonyl) phenyl] oxalate (CPPO) as a chemical energy source with high reactivity toward H₂O₂, poly[(9,9'-dioctyl-2,7-divinylene-fluorenylene)-alt-2-methoxy- 5-(2-ethyl-hexyloxy)-1,4-phenylene] (PFPV) as a highly efficient chemiluminescence converter, and tetraphenylporphyrin (TPP) as a photosensitizer with NIR emission and ¹O₂ generation abilities were coencapsulated by self-assembly with poly(ethyleneglycol)-co-poly(caprolactone) (PEG-PCL) and folate-PEG-cholesterol to form the POCL nanoreactor, with folate as the targeting group. A series of in vitro and in vivo analyses, including physical and chemical characterizations, tumor targeting ability, tumor microenvironment activated imaging and photodynamic therapy, as well as biosafety, were systematically investigated to characterize the POCL.

Results: The POCL displayed excellent NIR luminescence and ¹O₂ generation abilities in response to H₂O₂. Therefore, it could serve as a specific H₂O₂ probe to identify tumors through chemiluminescence imaging and as a chemiluminescence-driven PDT agent for inducing tumor cell apoptosis to inhibit tumor growth due to the abnormal overproduction of H₂O₂ in the tumor microenvironment. Moreover, the folate ligand on the POCL surface can further improve the accumulation at the tumor site via a receptor-mediated mechanism, thus enhancing tumor imaging and the therapeutic effects both in vitro and in vivo but without any observable systemic toxicity.

Conclusion: The nanosystem reported here might serve as a targeted, smart, precise, and noninvasive strategy triggered by the tumor microenvironment rather than by an outside light source for cancer NIR imaging and PDT treatment without limitations on penetration depth.

Genomic and transcriptional Profiling of tumor infiltrated CD8+ T cells revealed functional heterogeneity of antitumor immunity in hepatocellular carcinoma

As key players in HCC antitumor response, the functions of tumor infiltrated CD8⁺ T cells are significantly affected by surrounding microenvironment. A detailed profiling of their genomic and transcriptional changes could provide valuable insights for both future immunotherapy development and prognosis evaluation. We performed whole exome and transcriptome sequencing on tumor infiltrated CD8⁺ T cells and CD8⁺ T cells isolated from other tissue origins (peritumor tissues and corresponding PBMCs) in eight treatment-naive HCC patients. The results demonstrated that transcriptional changes, rather than genomic alterations were the main contributors to the functional alterations of CD8⁺ T cells in the process of tumor progression. The origins of CD8⁺ T cells defined their transcriptional landscape, while the tumor infiltrated CD8⁺ T cells shared more similarity with peritumor-derived CD8⁺ T cells compared with those CD8⁺ T cells in blood. In addition, tumor infiltrated CD8⁺ T cells also showed larger transcriptional heterogeneity among individuals, which was modulated by clinical features such as HBV levels, preoperative anti-viral treatment and the degree of T cell infiltration. We also identified multiple inter-connected pathways involved in the activation and exhaustion of tumor infiltrated CD8⁺ T cells, among which IL-12 mediated pathway could dynamically reflect the functional status of CD8⁺ TILs and activation of this pathway indicated a better prognosis. Our results presented an overview picture of CD8⁺ TILs' genomic and transcriptional landscape and features, as well as how the functional status of CD8⁺ TILs correlated with patients' clinical course.

pH/hypoxia programmable triggered cancer photo-chemotherapy based on a semiconducting polymer dot hybridized mesoporous silica framework

Although photothermal therapy (PTT) has become a compelling strategy for cancer therapy, few studies concern the physiological consequences of PTT ablation. Herein, we discover that PTT-induced hyperthermia can aggravate tumor hypoxia, which may increase the risk of tumor recurrence and reduce PTT efficacy. We thus integrated the pH/hypoxia-triggered Fe(iii)-banoxantrone (AQ4N) prodrug and semiconducting polymer dots (SPs) for programmable triggered cancer photothermal-chemotherapy. A SP-hybridized mesoporous silica framework, decorated by dopamine and polyethylene glycol, named PPMSF, was synthesized by a simple method, and then served as an efficient photo-absorbing agent (PTA) and drug carrier. Fe(iii)-AQ4N and Mn(ii) were then coordinated with PPMSF (abbreviated Mn-APPMSF) via coordination effects. The nanohybrids exhibited tumor micro-environment pH triggered drug release. Under the irradiation of NIR light, magnetic resonance imaging (MRI) tracked the accumulation of the nanohybrids in tumors which then destroyed tumor cells by local hyperthermia, this can consequently aggravate the tumor hypoxia levels. Intriguingly, the aggravated hypoxia can further enhance the reduction of AQ4N to significantly improve therapeutic efficacy and effectively inhibit tumor growth when compared with traditional PTT. These results indicate the potential of our nanohybrids as a programmable synergistic agent for cancer therapy.

Clonal evolution in long-term follow-up patients with hepatocellular carcinoma

To investigate tumor clonal evolution in hepatocellular carcinoma (HCC), we collected 31 tumor samples,16 peritumor samples and matched PBMCs from 11 long-term follow-up patients with HCC. Whole-exome sequencing was performed to obtain SNVs and CNVs for each sample. An average of 652.2 somatic mutations were identified in each patient and the mean percentage of nonubiquitous tumor mutations was 63.7% (range, 0.7%-100%), reflecting the variety of tumor heterogeneity. Further analysis of clonal evolution was conducted based on mutation clustering results and revealed that different clonal evolution patterns indeed existed in single and multifocal HCC while these patterns were significantly correlated to patients' clinical course. These patterns clearly demonstrated different mechanisms of tumor recurrence. During tumor clonal evolution, potential therapeutic targets also emerged and vanished dynamically. Moreover, mutation analysis revealed that the contribution of mutational signature was correlated with clonal evolution history. Target sequencing of follow-up plasma samples also confirmed that ctDNA level could dynamically reflect tumor clonal/subclonal burden. By investigating clonal evolution in HCC patients, our analysis revealed that different patterns indeed existed during HCC progression and proposed a novel strategy for identifying the origin of recurrent tumor as well as optimizing treatment selection.

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.