Dead Cancer Cells Research Articles

In Vivo Tracking and 3D Mapping of Cell Death in Regeneration and Cancer Using Trypan Blue.

Tracking cell death in vivo can enable a better understanding of the biological mechanisms underlying tissue homeostasis and disease. Unfortunately, existing cell death labeling methods lack compatibility with in vivo applications or suffer from low sensitivity, poor tissue penetration, and limited temporal resolution. Here, we fluorescently labeled dead cells in vivo with Trypan Blue (TBlue) to detect single scattered dead cells or to generate whole-mount three-dimensional maps of large areas of necrotic tissue during organ regeneration. TBlue effectively marked different types of cell death, including necrosis induced by CCl4 intoxication in the liver, necrosis caused by ischemia-reperfusion in the skin, and apoptosis triggered by BAX overexpression in hepatocytes. Moreover, due to its short circulating lifespan in blood, TBlue labeling allowed in vivo "pulse and chase" tracking of two temporally spaced populations of dying hepatocytes in regenerating mouse livers. Additionally, upon treatment with cisplatin, TBlue labeled dead cancer cells in livers with cholangiocarcinoma and dead thymocytes due to chemotherapy-induced toxicity, showcasing its utility in assessing anticancer therapies in preclinical models. Thus, TBlue is a sensitive and selective cell death marker for in vivo applications, facilitating the understanding of the fundamental role of cell death in normal biological processes and its implications in disease.

Carbon Ion Irradiation Activates Anti-Cancer Immunity.

Carbon ion beams have the unique property of higher linear energy transfer, which causes clustered damage of DNA, impacting the cell repair system. This sometimes triggers apoptosis and the release in the cytoplasm of damaged DNA, leading to type I interferon (IFN) secretion via the activation of the cyclic GMP-AMP synthase-stimulator of interferon genes pathway. Dendritic cells phagocytize dead cancer cells and damaged DNA derived from injured cancer cells, which together activate dendritic cells to present cancer-derived antigens to antigen-specific T cells in the lymph nodes. Thus, carbon ion radiation therapy (CIRT) activates anti-cancer immunity. However, cancer is protected by the tumor microenvironment (TME), which consists of pro-cancerous immune cells, such as regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. The TME is too robust to be destroyed by the CIRT-mediated anti-cancer immunity. Various modalities targeting regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages have been developed. Preclinical studies have shown that CIRT-mediated anti-cancer immunity exerts its effects in the presence of these modalities. In this review article, we provide an overview of CIRT-mediated anti-cancer immunity, with a particular focus on recently identified means of targeting the TME.

A tumor on a chip for studying immune-cell infiltration into tumor under chemo/immunotherapy treatments

The combo treatment of chemo/immunotherapy is a promising method in treating cancer patients. The results of Keynote-189 phase III clinical trial showed that chemotherapy drug plus immunotherapy drug reduced mortality compared with chemotherapy drug alone, in which the underlying mechanism has not been well demonstrated. The treatment combination also needs to be tuned for each patient, i.e., personalized medicine. Tumor-on-a-chip aims to mimic the tumor microenvironment (TME) with an in-vitro lung cancer-immune model to provide a potential solution for this application. Gelatin methacryloyl (GelMA)-cancer cells were driven on the ITO electrode track using liquid dielectrophoresis (LDEP) to form the tumor-like hydrogel. Jurkat T cells surrounded the solidified GelMA-A549 cells, resembling the cancer-immune microenvironment. The immune-cell infiltration phenomena of Jurkat T cells into the tumor were activated and enhanced via either IL-1β-treated A549 cells or atezolizumab (immune drugs) on the tumor lab chip. The death of cancer cells significantly increased ∼35% after chemo/immunotherapy combination treatment compared with the single treatment. The distribution of dead cancer cells treated with chemo/immunotherapy revealed their distinct theoretical mechanisms, indicating the promising application of this tumor lab chip for cancer patients in personalized medicine treatments.

Gold standard assessment of immunogenic cell death induced by photodynamic therapy: From in vitro to tumor mouse models and anti-cancer vaccination strategies.

The discovery of the concept of immunogenic cell death (ICD) is a cornerstone in the development of novel anti-cancer immunotherapeutic approaches. Induction of the ICD pathway by specific anti-cancer therapeutic regimens can eliminate cancer cells by directly killing them during therapy and by activation of strong and specific anti-cancer immunity, leading to a long-lasting immunological memory that prevents cancer recurrence. ICD encompasses different forms of regulated cell death and can be triggered by many anti-cancer treatment modalities, including photodynamic therapy (PDT). PDT is a multistep procedure involving the accumulation of a light-sensitive dye known as a photosensitizer (PS) in tumor cells, followed by its activation by irradiation with a light of an appropriate wavelength. In the presence of molecular oxygen, the irradiated PS leads to the generation of cytotoxic reactive oxygen species, which can lead to ICD induction in the cancer cells. Here, we first describe in vitro methods to help optimize the PDT procedure for a specific PS. We also provide a collection of protocols and techniques for assessing ICD in vitro, including analysis of the emission of damage associated molecular patterns (DAMPs), efferocytosis, and the maturation and activation state of antigen presenting cells. Next, we describe in detail protocols for diverse tumor mouse models for assessing and characterizing ICD in vivo, such as murine tumor vaccination models. Finally, as an immunotherapeutic vaccine, we suggest using either PDT-induced dead cancer cells, preferably undergoing ICD, or dendritic cells loaded with lysates of PDT-induced cancer cells in a syngeneic orthotopic glioma model. Overall, this methodological article provides a quantitative, comprehensive set of validated tools that can be successfully used, with some adaptations, to identify, optimize and validate novel PSs in vitro and in vivo for the efficient induction of ICD during photodynamic treatment.

Single-Cell MTT: A Simple and Sensitive Assay for Determining the Viability and Metabolic Activity of Polyploid Giant Cancer Cells (PGCCs).

Solid tumors and tumor-derived cell lines commonly contain highly enlarged (giant) cancer cells that enter a state of transient dormancy (active sleep) after they are formed, but retain viability, secrete growth promoting factors, and exhibit the ability to generate rapidly proliferating progeny with stem cell-like properties. Giant cells with a highly enlarged nucleus or multiple nuclei are often called polyploid giant cancer cells (PGCCs). Although PGCCs constitute only a subset of cells within a solid tumor/tumor-derived cell line, their frequency can increase markedly following exposure to ionizing radiation or chemotherapeutic drugs. In this chapter we outline a simple and yet highly sensitive cell-based assay, called single-cell MTT, that we have optimized for determining the viability and metabolic activity of PGCCs before and after exposure to anticancer agents. The assay measures the ability of individual PGCCs to convert the MTT tetrazolium salt to its water insoluble formazan metabolite. In addition to evaluating PGCCs, this assay is also a powerful tool for determining the viability and metabolic activity of cancer cells undergoing premature senescence following treatment with anticancer agents, as well as for distinguishing dead cancer cells and dying cells (e.g., exhibiting features of apoptosis, ferroptosis, etc.) that have the potential to resume proliferation through a process called anastasis.

PD-L1-expressing cancer-associated fibroblasts induce tumor immunosuppression and contribute to poor clinical outcome in esophageal cancer

The programmed cell death 1 protein (PD-1)/programmed cell death ligand 1 (PD-L1) axis plays a crucial role in tumor immunosuppression, while the cancer-associated fibroblasts (CAFs) have various tumor-promoting functions. To determine the advantage of immunotherapy, the relationship between the cancer cells and the CAFs was evaluated in terms of the PD-1/PD-L1 axis. Overall, 140 cases of esophageal cancer underwent an immunohistochemical analysis of the PD-L1 expression and its association with the expression of the α smooth muscle actin, fibroblast activation protein, CD8, and forkhead box P3 (FoxP3) positive cells. The relationship between the cancer cells and the CAFs was evaluated in vitro, and the effect of the anti-PD-L1 antibody was evaluated using a syngeneic mouse model. A survival analysis showed that the PD-L1+ CAF group had worse survival than the PD-L1- group. In vitro and in vivo, direct interaction between the cancer cells and the CAFs showed a mutually upregulated PD-L1 expression. In vivo, the anti-PD-L1 antibody increased the number of dead CAFs and cancer cells, resulting in increased CD8+ T cells and decreased FoxP3+ regulatory T cells. We demonstrated that the PD-L1-expressing CAFs lead to poor outcomes in patients with esophageal cancer. The cancer cells and the CAFs mutually enhanced the PD-L1 expression and induced tumor immunosuppression. Therefore, the PD-L1-expressing CAFs may be good targets for cancer therapy, inhibiting tumor progression and improving host tumor immunity.

Reinforcing the immunogenic cell death to enhance cancer immunotherapy efficacy.

Immunogenic cell death (ICD) has been a revolutionary modality in cancer treatment since it kills primary tumors and prevents recurrent malignancy simultaneously. ICD represents a particular form of cancer cell death accompanied by production of damage-associated molecular patterns (DAMPs) that can be recognized by pattern recognition receptors (PRRs), which enhances infiltration of effector T cells and potentiates antitumor immune responses. Various treatment methods can elicit ICD involving chemo- and radio-therapy, phototherapy and nanotechnology to efficiently convert dead cancer cells into vaccines and trigger the antigen-specific immune responses. Nevertheless, the efficacy of ICD-induced therapies is restrained due to low accumulation in the tumor sites and damage of normal tissues. Thus, researchers have been devoted to overcoming these problems with novel materials and strategies. In this review, current knowledge on different ICD modalities, various ICD inducers, development and application of novel ICD-inducing strategies are summarized. Moreover, the prospects and challenges are briefly outlined to provide reference for future design of novel immunotherapy based on ICD effect.

Targeted delivery of novel Au(I)-based AIEgen via inactivated cancer cells for trimodal chemo-radio-immunotherapy and vaccination against advanced tumor

Radiotherapy-induced immunogenic cell death (ICD) has been proven to be an effective strategy for evoking immunotherapeutic effects against advanced tumors. Components from the dead cancer cells have been shown to serve as natural drug carriers and have also demonstrated great advantages in tumor-targeted delivery and immune activation. Herein, we constructed an inactivated cancer cells vector for novel Au(I)-based AIEgen (complex 1) AIEgen to augment the targeted delivery of AIEgen toward tumor tissue. More importantly, the AIEgen exerted toxicity against cancer cells and mainly localized within the endoplasmic reticulum and part of lysosome. Upon X-ray irradiation, a synergistic therapeutic effects of trimodal chemo-radio-immunotherapy was achieved, where the AIEgen effectively induced ICD by triggering ROS production and DNA damage. Further, it stimulated a robust systemic antitumor immune response via the upregulation of various cytokines and the activation of the cGAS-STING pathway, thereby activating innate and adaptive immunity in melanoma tumor model. Furthermore, in vivo, the ICD-inducing immunogenicity of AIEgen combined with radiotherapy served as a cancer cell vaccine strategy to inhibit tumorigenesis. This approach engineered strategy based on dead cancer cells vector serves as a bridge combining AIEgen, chemotherapy, radiotherapy, and immunotherapy, and provides a simple and effective scheme for trimodal chemo-radio-immunotherapy and improving therapeutic effects.

Cancer Immunotherapy Elicited by Immunogenic Cell Death Based on Smart Nanomaterials (Small Methods 5/2023)

Inside Front Cover In article number 2201381, Haidong Li, Juyoung Yoon, and co-workers review smart nanomaterials that can target lesion sites passively/actively and release immunogenic cell death (ICD) inducers on-demand, which can turn the dead cancer cells into endogenous vaccines, eliciting a systemic antigen-specific antitumor. The improved accumulation of the ICD inducers at the tumor site not only enhances the therapeutic effect of cancer immunotherapy but also prevents damage to normal tissues.

Abstract 4559: Evaluation of the chemotherapy potential to improve the anti-cancer efficacy of PD-L1 inhibition using novel 3D microfluidic co-culture platform

Abstract Immunotherapy is now recognized as a powerful therapeutic approach to treat and cure cancer. However, the objective response rates for most solid tumors are low (below 30%). Accumulating evidence has shown that chemotherapy can increase the efficacy of immune checkpoint blockade and improve cancer outcomes. We have investigated if chemotherapy can modulate anti-PDL1 enhanced T cell cytotoxicity in breast cancer using novel in vitro 3D co-culture assay system. 3D co-culture of cancer and immune cells is a powerful platform for disease modeling and therapies testing because it can mimic the tumor micro-environment and complex cellular interactions. In this study we evaluated the immunomodulatory effect of chemotherapy on spheroid-T cells interactions in response to PD-L1 inhibition in triple-negative breast cancer. MCF7 and MDA231 cell lines with differential PD-L1 status were formed into spheroids and used as a tumor model. T cells were activated from PBMCs using ImmunoCult CD3/CD28 T cell Activator. Co-culture assays were performed over 72 hr in a Pu·MA System. The Pu·MA System is an automated microfluidic platform that enables phenotypic and functional assays using physiologically relevant 3D cell models. Cancer spheroids and T cells were cultured, manipulated, and measured in a single well of a microfluidic flowchip. The platform integrates 1) 3D cell model with delivery of immune cells, 2) drug delivery, 3) imaging of phenotypic features and 4) functional profiling for cytokine secretion and viability. T cells-spheroid interaction, invasion and cell viability was assessed using high-content fluorescence imaging CellVoyager CQ1 system. IL2, IFN-γ and TNF-α secretion was measured in collected supernatants using Lumit immunoassays. After viability determination, co-cultures were fixed and stained for cancer and T cell markers (E-Cadherin, F-Actin, CD3, CD8) using automated IF staining protocol and then imaged. Image analysis revealed colocalization and infiltration of the T cells into the spheroids. Disintegration of spheroid, loss of circular shape, and increased number of dead cancer cells indicated T cell mediated cancer cell death. To evaluate the immunomodulatory effect of chemotherapy on spheroid-T cells interactions in response to PD-L1 inhibition, co-cultures were exposed to PD-L1 inhibitor Atezolizumab in the presence or absence of Cisplatin/Pemetrexed. We have analyzed a shift in T cell-mediated killing activity and function in the presence or absence of chemotherapeutics. The proposed co-culture platform can be further extended to a more complex patient-derived 3D models using different cell types. Our functional immune-oncology 3D platform allows to study the crosstalk between immune, cancer and other cell interactions, evaluate new drug candidates and assess individual therapeutic approaches to advance precision medicine. Citation Format: Ekaterina Moroz Nikolov, Anthony Thai, Lila Cooper, Mahomi Suzuki, Arvonn Tully, Rashmi Rajendra, Evan F. Cromwell. Evaluation of the chemotherapy potential to improve the anti-cancer efficacy of PD-L1 inhibition using novel 3D microfluidic co-culture platform. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4559.

Metabolic Recycling Enhances Proliferation in MYC‐Transformed Lymphoma B Cells (Adv. Biology 2/2023)

Metabolic Recycling In article number 2200233, Anne Le and co-workers study cancer relapse after treatment and the phenomenon of metabolic recycling, which may help to partially explain why cancer relapse occurs. Specifically, they find that surviving live cancer cells are able to take up the metabolites from the post-therapy environment containing debris of the dead cancer cells and incorporate these metabolites into their metabolism, thus promoting proliferation.

Cancer Immunotherapy Elicited by Immunogenic Cell Death Based on Smart Nanomaterials.

Cancer immunotherapy has been a revolutionary cancer treatment modality because it can not only eliminate primary tumors but also prevent metastases and recurrent tumors. Immunogenic cell death (ICD) induced by various treatment modalities, including chemotherapy, phototherapy, and radiotherapy, converts dead cancer cells into therapeutic vaccines, eliciting a systemic antigen-specific antitumor. However, the outcome effect of cancer immunotherapy induced by ICD has been limited due to the low accumulation efficiency of ICD inducers in the tumor site and concomitant damage to normal tissues. The boom in smart nanomaterials is conducive to overcoming these hurdles owing to their virtues of good stability, targeted lesion site, high bioavailability, on-demand release, and good biocompatibility. Herein, the design of targeted nanomaterials, various ICD inducers, and the applications of nanomaterials responsive to different stimuli, including pH, enzymes, reactive oxygen species, or dual responses are summarized. Furthermore, the prospect and challenges are briefly outlined to provide reference and inspiration for designing novel smart nanomaterials for immunotherapy induced by ICD.

Solid-state emitting twisted π-conjugate as AIE-active DSE-gen: in vitro anticancer properties against FaDu and 4T1 with biocompatibility and bioimaging.

Dual-state emissive fluorogens (DSE-gens) are currently defining their importance as a transpiring tool in biological and biomedical applications. This work focuses on designing and synthesizing indole-anthracene-based solid-state emitting twisted π-conjugates using a metal-free protocol to achieve AIE-active DSE-gens, expanding their scope in biological applications. Special effort has been made to introduce proficient and photo/thermostable DSE-gens that inhibit cancer but not normal cells. Here, the lead DSE-gen initially detects cancer and normal cells by bioimaging; however, it could also confirm and distinguish cancer cells from normal cells by its abated fluorescence signal after killing cancer cells. In contrast, the fluorescence signals for a normal cell remain unscathed. Surprisingly, these molecules displayed decent anticancer properties against FaDu and 4T1 but not MCF-7 cell lines. From a series of newly designed indole-based molecules, we report one single 2,3,4-trimethoxybenzene-linked DSE-gen (the lead), exhibiting high ROS generation, less haemolysis, and less cytotoxicity than doxorubicin (DOX) for normal cells, crucial parameters for a biocompatible in vitro anticancer probe. Thus, we present a potentially applicable anticancer drug, offering a bioactive material with bioimaging efficacy and a way to detect dead cancer cells selectively. The primary mechanism behind the identified outcomes is deciphered with the support of experimental (steady-state and time-resolved fluorescence, biological assays, cellular uptake) and molecular docking studies.

Metabolic Recycling Enhances Proliferation in MYC-Transformed Lymphoma B Cells.

Relapses negatively impact cancer patient survival due to the tumorigenesis ability of surviving cancer cells post-therapy. Efforts are needed to better understand and combat this problem. This study hypothesized that dead cell debris post-radiation therapy creates an advantageous microenvironment rich in metabolic materials promoting the growth of remaining live cancer cells. In this study, live cancer cells are co-cultured with dead cancer cells eradicated by UV radiation to mimic a post-therapy environment. Isotopic labeling metabolomics is used to investigate the metabolic behavior of cancer cells grown in a post-radiation-therapy environment. It is found that post-UV-eradicated dead cancer cells serve as nutritional sources of "off-the-shelf" and precursor metabolites for surviving cancer cells. The surviving cancer cells then take up these metabolites, integrate and upregulate multiple vital metabolic processes, thereby significantly increasing growth in vitro and probably in vivo beyond their intrinsic fast-growing characteristics. Importantly, this active metabolite uptake behavior is only observed in oncogenic but not in non-oncogenic cells, presenting opportunities for therapeutic approaches to interrupt the active uptake process of oncogenic cells without affecting normal cells. The process by which living cancer cells re-use vital metabolites released by dead cancer cells post-therapy is coined in this study as "metabolic recycling" of oncogenic cells.

Suppression of high mobility group box 1 in B16F10 tumor does not inhibit the induction of neoantigen-specific T cells.

Accumulated clinical data of immune checkpoint blockades have suggested the importance of neoantigens in cancer immunity. Tumor antigens are released from dead cancer cells together with cellular components, such as damage-associated molecular patterns (DAMPs), into the tumor microenvironment. We recently reported that high mobility group box 1 (HMGB1), a representative DAMP molecule, showed a negative impact on anti-tumor immunity. However, a positive role of HMGB1 in the initiation of innate and subsequent adaptive immunity has also been demonstrated; thus, the effects of HMGB1 on anti-tumor immunity have not been well understood. In this study, we identified nine immunogenic neoantigen epitopes of B16F10 murine melanoma cells and subsequently investigated the effects of suppression of HMGB1 on the induction of neoantigen-specific immunity using HMGB1-knockout tumors. Neoantigen-reactive T cells were expanded in B16F10 tumor-bearing mice, and T cell receptor repertoire analysis suggested that neoantigen-reactive T cells were oligo-clonally increased in B16F10 tumor bearers. An increase of neoantigen-reactive T cells and oligoclonal expansion of the T cells were similarly detected in HMGB1-knockout tumor-bearing mice. The induction of neoantigen-specific immunity under the suppression of HMGB1 in the tumor microenvironment shown in this study supports further development of combination therapy of HMGB1 suppression with neoantigen-targeted cancer immunotherapies, including immune checkpoint blockade therapy.

The intersection molecule MDA5 in Cancer and COVID-19.

The connections between pattern recognition receptors (PRRs) and pathogen-associated molecular patterns (PAMPs) constitutes the crucial signaling pathways in the innate immune system. Cytoplasmic nucleic acid sensor melanoma differentiation-associated gene 5 (MDA5) serves as an important pattern recognition receptor in the innate immune system by recognizing viral RNA. MDA5 also plays a role in identifying the cytoplasmic RNA from damaged, dead cancer cells or autoimmune diseases. MDA5’s recognition of RNA triggers innate immune responses, induces interferon (IFN) response and a series of subsequent signaling pathways to produce immunomodulatory factors and inflammatory cytokines. Here we review the latest progress of MDA5 functions in triggering anti-tumor immunity by sensing cytoplasmic dsRNA, and recognizing SARS-CoV-2 virus infection for antiviral response, in which the virus utilizes multiple ways to evade the host defense mechanism.

Suppression of resistance to aminolevulinic acid-based photodynamic therapy in esophageal cell lines by administration of iron chelators in collagen type I matrices

Purpose Photodynamic therapy (PDT) utilizes visible light to activate the cytotoxic effects of photosensitizing drugs. PDT protocols require optimization to overcome treatment resistance and induce a beneficial anti-tumor immune response. The aim of this study was to examine the possibility to suppress the resistance of esophageal cell lines to aminolevulinic acid (ALA)-PDT by administration of iron chelators to induce sufficient cell cytotoxicity under pathophysiologically relevant conditions, mimicking the advanced stages of cancer. Materials and methods Effects of ALA-PDT in combination with iron chelators were compared in three esophageal cell lines in conventional monolayers and in 3 D cultures based on collagen type I. Modified colony assay and fluorescence-based live cell imaging, respectively were applied. The latter was used also to test the capability of pre-polarized macrophages to interact with cancer cells subjected to ALA-PDT with or without iron chelators. Results Iron chelators were effective in the enhancement of ALA-PDT in all cell lines under both culture conditions. Fluorescence evaluation of cell viability in 3 D cultures indicated the contribution of apoptotic cell death after ALA-PDT, both with and without iron chelators. Engulfment of remnants of dead cancer cells by macrophages in 2 D cultures was indicated, however, the interaction between macrophages and cancer cells in 3 D cultures subjected to ALA-PDT with or without iron chelators was not present. Conclusions The potential of iron chelators to enhance ALA-PDT was maintained in 3 D collagen matrices. Although PDT dose (ALA concentration, light exposure time) required modification in a cell line-dependent manner to achieve a comparable effect of PDT alone in conventional monolayers and in collagen matrices, the potential of iron chelators to suppress the resistance of esophageal cells to ALA-PDT was not influenced by a fibrillar collagen matrix.

Potential of the Coordinated Actions of Multiple Protein-Based Micromachines for Medical Applications.

Untethered mobile micromachines hold great promise in the development of effective and minimally invasive therapies. Although diverse medical micromachines for specific applications have been developed over the past few decades, the coordinated action of multiple machines with different functions remains largely unexplored. In this study, we created three types of biocompatible micromachines using proteins and demonstrated the potential of their coordinated action for medical applications. As a proof of concept, we demonstrated neural replacement therapy, in which neuroblastomas were killed by using an anticancer prodrug and the first machine that contains enzymes, enabling the conversion of the prodrug into a cytotoxic drug. Subsequently, a second machine composed of extracellular matrix was placed on the dead cancer cells to provide a suitable environment for cell adhesion, on which embryonic stem (ES) cells and stromal cells that promote neural differentiation of stem cells were attached by using third machines capable of delivering cells to target positions with desired patterns. As a result, neuroblastomas were replaced with novel healthy neurons derived from ES cells by teaming multiple protein-based machines. We believe that this work highlights the potential of heterogeneous machine groups for medical treatment and the utility of highly biocompatible and functional micromachines made from proteins, representing an important step forward in building more sophisticated micromachine-based therapies.

Cell-Selective Encapsulation within Metal-Organic Framework Shells via Precursor-Functionalized Aptamer Identification for Whole-Cell Cancer Vaccine.

Single-cell encapsulation is an emerging technology to endow cells with various functions, of which developing new applications in vivo is in high demand. Currently, metal-organic frameworks (MOFs) that are used as nanometric shells to coat living cells, however, have not realized cell-selective encapsulation. Here, a biocompatible and selective cell encapsulation strategy based on precursor-functionalized nucleolin aptamer and in situ MOF mineralization on the aptamer-identified cancer cell surface are developed. After MOF coating, the encapsulated cancer cells undergo immunogenic cell death, which is found associated with the changed cell stiffness (indicated by Young's modulus). The immunogenic dead cancer cells are used as whole-cell cancer vaccines (WCCVs), forming the integral WCCV-in-shell structure with enhanced immunogenicity ascribing from the surface-exposed calreticulin to promote dendritic cell recruitment, antigen presentation, and T-cell activation. The major activation pathways in the immune response are identified including tumor necrosis factor signaling pathway, cytokine-cytokine receptor interaction, and Toll-like receptor signaling pathway, suggesting the potential adjuvant effect of the MOF shells. After vaccination, WCCV-in-shell shows much better tumor immunoprophylaxis than either the imperfectly coated cancer cells or the traditional WCCV. This strategy is promising for the universal and facile development of novel whole-cell vaccines.

Photothermal Therapy: A New Approach to Eradicate Cancer

: The use of hyperthermal temperature to treat solid cancers is known as oncological thermal ablation. Thermal ablation is studied as a therapeutic strategy for most cancers and can be used in the control of local and metastatic diseases in addition to traditional anticancer therapies. PTT (photothermal therapy) is a minimally invasive therapeutic approach with a promising diagnostic and cancer prevention potential. The excitation of photosensitizer materials like inorganic and organic nanomaterials with NIR (near-infrared radiation) showed significantly better results than the traditional mode of cancer treatment. The penetration depth of NIR is significantly higher as compared to the U.V. (ultraviolet) and visible light. Photo-excitation of the nanomaterials with NIR efficiently converts light energy into heat energy and eventually enables the cancer cells to die due to heat shock. The addition of a multimodal approach to the treatment and the prevention of cancer cells thermo-resistant properties in localized and distal tumors involves the combination of photothermal agents and chemotherapy. Cancer cell hyperthermic activation prevents DNA repair, cell survival signaling and eventually induces apoptosis. Simultaneously, the release of antigenic peptides from the dead cancer cells activates the immune cells which kill the localized and metastatic cancer cells, hence enabling long-term immunological memory retention. The present review summarizes PTT's functional properties, NIR penetration ability, DNA repair, cellular signaling, and immune system modulation effect of hyperthermia. The benefits of using different types of nanomaterials in PTT applications are further explored. In addition, the problems associated with the use of nanomaterials in PTT applications are also addressed in this article.