Cancer stem cell antigen nanodisc cocktail elicits anti-tumor immune responses in melanoma

New insights on anti-tumor immunity of CD8+ T cells: cancer stem cells, tumor immune microenvironment and immunotherapy

Recent breakthroughs in tumor immunotherapy have confirmed the capacity of the immune system to fight several cancers. The effective means of treating cancer involves accelerating the death of tumor cells and improving patient immunity. Dynamic changes in the tumor immune microenvironment alter the actual effects of anti-tumor drug production and may trigger favorable or unfavorable immune responses by modulating tumor-infiltrating lymphocytes. Notably, CD8+ T cells are one of the primary tumor-infiltrating immune cells that provide anti-tumor response. Tumor cells and tumor stem cells will resist or evade destruction through various mechanisms as CD8+ T cells exert their anti-tumor function. This paper reviews the research on the regulation of tumor development and prognosis by cancer stem cells that directly or indirectly alter the role of tumor-infiltrating CD8+ T cells. We also discuss related immunotherapy strategies.

Breaking Immunosuppression to Enhance Cancer Stem Cell-Targeted Immunotherapy

Cancer stem cell (CSC)-targeted immunotherapy has emerged as a novel strategy in cancer treatment in the past decade. However, its efficacy is significantly limited due to the existence of host immune suppressive activity. Specifically, programmed cell death ligand-1 (PD-L1) is overexpressed in CSCs, and PD-L1 overexpressed CSCs create immunosuppressive milieu via interacting with various immune cells in tumor microenvironments (TME). Hence, novel immunotherapeutic strategies targeting CSCs with concurrent immunosuppression interruption will be promising in enhancing anti-CSC effects. These include dendritic cell (DC) and nanodisc (ND)-based vaccines to present CSC antigens in the forms of CSC lysate, CSC-marker proteins, and CSC-derived peptides to induce anti-CSC immunity. In addition, CSC-directed bispecific antibodies (BiAbs) and antibody drug conjugates (ADCs) have been developed to target CSCs effectively. Furthermore, chimeric antigen receptor (CAR)-T cell therapy and natural killer (NK) cell-based therapy targeting CSCs have achieved progress in both solid and hematologic tumors, and inhibition of CSC associated signaling pathways has proven successful. In this review, we aimed to outline the roles and regulatory mechanisms of PD-L1 in the properties of CSCs; the crosstalk between CSCs and immunosuppressive cells in TME, and recent progress and future promises of immunosuppression blockage to enhance CSC-targeted immunotherapy.

Advances in the delivery of anticancer drugs by nanoparticles and chitosan-based nanoparticles

Cancer is the leading cause of death globally, and conventional treatments have limited efficacy with severe side effects. The use of nanotechnology has the potential to reduce the side effects of drugs by creating efficient and controlled anticancer drug delivery systems. Nanoparticles (NPs) used as drug carriers offer several advantages, including enhanced drug protection, biodistribution, selectivity and, pharmacokinetics. Therefore, this review is devoted to various organic (lipid, polymeric) as well as inorganic nanoparticles based on different building units and providing a wide range of potent anticancer drug delivery systems. Within these nanoparticulate systems, chitosan (CS)-based NPs are discussed with particular emphasis due to the unique properties of CS and its derivatives including non-toxicity, biodegradability, mucoadhesivity, and tunable physico-chemical as well as biological properties allowing their alteration to specifically target cancer cells. In the context of streamlining the nanoparticulate drug delivery systems (DDS), innovative nanoplatform-based cancer therapy pathways involving passive and active targeting as well as stimuli-responsive DDS enhancing overall orthogonality of developed NP-DDS towards the target are included. The most up-to-date information on delivering anti-cancer drugs using modern dosage forms based on various nanoparticulate systems and, specifically, CSNPs, are summarised and evaluated concerning their benefits, limitations, and advanced applications.

Novel immunotherapeutic approaches in gastric cancer

Gastric cancer is a malignant tumor that ranks third in cancer-related deaths worldwide. Early-stage gastric cancer can often be effectively managed through surgical resection. However, the majority of cases are diagnosed in advanced stages, where outcomes with conventional radiotherapy and chemotherapy remain unsatisfactory. Immunotherapy offers a novel approach to treating molecularly heterogeneous gastric cancer by modifying the immunosuppressive tumor microenvironment. Immune checkpoint inhibitors and adoptive cell therapy are regarded as promising modalities in cancer immunotherapy. Food and Drug Administration-approved programmed death-receptor inhibitors, such as pembrolizumab, in combination with chemotherapy, have significantly extended overall survival in gastric cancer patients and is recommended as a first-line treatment. Despite challenges in solid tumor applications, adoptive cell therapy has demonstrated efficacy against various targets in gastric cancer treatment. Among these approaches, chimeric antigen receptor-T cell therapy research is the most widely explored and chimeric antigen receptor-T cell therapy targeting claudin18.2 has shown acceptable safety and robust anti-tumor capabilities. However, these advancements primarily remain in preclinical stages and further investigation should be made to promote their clinical application. This review summarizes the latest research on immune checkpoint inhibitors and adoptive cell therapy and their limitations, as well as the role of nanoparticles in enhancing immunotherapy.

WTAP/IGF2BP3 mediated m6A modification of the EGR1/PTEN axis regulates the malignant phenotypes of endometrial cancer stem cells

Endometrial cancer (EC) stem cells (ECSCs) are pivotal in the oncogenesis, metastasis, immune escape, chemoresistance, and recurrence of EC. However, the specific mechanism of stem cell maintenance in EC cells (ECCs) has not been clarified. We found that WTAP and m6A levels decreased in both EC and ECSCs, and that knocking down WTAP promoted ECCs and ECSCs properties, including proliferation, invasion, migration, cisplatin resistance, and self-renewal. The downregulation of WTAP leads to a decrease in the m6A modification of EGR1 mRNA, and it is difficult for IGF2BP3, as an m6A reader, to recognize and bind to EGR1 mRNA that has lost m6A modification, resulting in a decrease in the stability of EGR1 mRNA. A decrease in the EGR1 level led to a decrease of in the expression tumor suppressor gene PTEN, resulting in deregulation and loss of cellular homeostasis and thereby fostering EC stem cell traits. Notably, the enforced overexpression of WTAP, EGR1, and PTEN inhibited the oncogenic effects of ECCs and ECSCs in vivo, and the combined overexpression of WTAP + EGR1 and EGR1 + PTEN further diminished the tumorigenic potential of these cells. Our findings revealed that the WTAP/EGR1/PTEN pathway is important regulator of EC stem cell maintenance, chemotherapeutic resistance, and tumorigenesis, suggesting a novel and promising therapeutic avenue for treating EC.

Nanobiotechnology augmented cancer stem cell guided management of cancer: liquid-biopsy, imaging, and treatment

Cancer stem cells (CSCs) represent both a key driving force and therapeutic target of tumoral carcinogenesis, tumor evolution, progression, and recurrence. CSC-guided tumor diagnosis, treatment, and surveillance are strategically significant in improving cancer patients' overall survival. Due to the heterogeneity and plasticity of CSCs, high sensitivity, specificity, and outstanding targeting are demanded for CSC detection and targeting. Nanobiotechnologies, including biosensors, nano-probes, contrast enhancers, and drug delivery systems, share identical features required. Implementing these techniques may facilitate the overall performance of CSC detection and targeting. In this review, we focus on some of the most recent advances in how nanobiotechnologies leverage the characteristics of CSC to optimize cancer diagnosis and treatment in liquid biopsy, clinical imaging, and CSC-guided nano-treatment. Specifically, how nanobiotechnologies leverage the attributes of CSC to maximize the detection of circulating tumor DNA, circulating tumor cells, and exosomes, to improve positron emission computed tomography and magnetic resonance imaging, and to enhance the therapeutic effects of cytotoxic therapy, photodynamic therapy, immunotherapy therapy, and radioimmunotherapy are reviewed.

Sniping Cancer Stem Cells with Nanomaterials

Cancer stem cells (CSCs) drive tumor initiation, progression, and therapeutic resistance due to their self-renewal and differentiation capabilities. Despite encouraging progress in cancer treatment, conventional approaches often fail to eliminate CSCs, necessitating the development of precise targeted strategies. Recent advances in materials science and nanotechnology have enabled promising CSC-targeted approaches, harnessing the power of tailoring nanomaterials in diverse therapeutic applications. This review provides an update on the current landscape of nanobased precision targeting approaches against CSCs. We elucidate the nuanced application of organic, inorganic, and bioinspired nanomaterials across a spectrum of therapeutic paradigms, encompassing targeted therapy, immunotherapy, and multimodal synergistic therapies. By examining the accomplishments and challenges in this potential field, we aim to inform future efforts to advance nanomaterial-based therapies toward more effective "sniping" of CSCs and tumor clearance.

Injectable hydrogels for personalized cancer immunotherapies

The field of cancer immunotherapy has shown significant growth, and researchers are now focusing on effective strategies to enhance and prolong local immunomodulation. Injectable hydrogels (IHs) have emerged as versatile platforms for encapsulating and controlling the release of small molecules and cells, drawing significant attention for their potential to enhance antitumor immune responses while inhibiting metastasis and recurrence. IHs delivering natural killer (NK) cells, T cells, and antigen-presenting cells (APCs) offer a viable method for treating cancer. Indeed, it can bypass the extracellular matrix and gradually release small molecules or cells into the tumor microenvironment, thereby boosting immune responses against cancer cells. This review provides an overview of the recent advancements in cancer immunotherapy using IHs for delivering NK cells, T cells, APCs, chemoimmunotherapy, radio-immunotherapy, and photothermal-immunotherapy. First, we introduce IHs as a delivery matrix, then summarize their applications for the local delivery of small molecules and immune cells to elicit robust anticancer immune responses. Additionally, we discuss recent progress in IHs systems used for local combination therapy, including chemoimmunotherapy, radio-immunotherapy, photothermal-immunotherapy, photodynamic-immunotherapy, and gene-immunotherapy. By comprehensively examining the utilization of IHs in cancer immunotherapy, this review aims to highlight the potential of IHs as effective carriers for immunotherapy delivery, facilitating the development of innovative strategies for cancer treatment. In addition, we demonstrate that using hydrogel-based platforms for the targeted delivery of immune cells, such as NK cells, T cells, and dendritic cells (DCs), has remarkable potential in cancer therapy. These innovative approaches have yielded substantial reductions in tumor growth, showcasing the ability of hydrogels to enhance the efficacy of immune-based treatments. STATEMENT OF SIGNIFICANCE: As cancer immunotherapy continues to expand, the mode of therapeutic agent delivery becomes increasingly critical. This review spotlights the forward-looking progress of IHs, emphasizing their potential to revolutionize localized immunotherapy delivery. By efficiently encapsulating and controlling the release of essential immune components such as T cells, NK cells, APCs, and various therapeutic agents, IHs offer a pioneering pathway to amplify immune reactions, moderate metastasis, and reduce recurrence. Their adaptability further shines when considering their role in emerging combination therapies, including chemoimmunotherapy, radio-immunotherapy, and photothermal-immunotherapy. Understanding IHs' significance in cancer therapy is essential, suggesting a shift in cancer treatment dynamics and heralding a novel period of focused, enduring, and powerful therapeutic strategies.

Cancer stem cells and their niche in cancer progression and therapy

High recurrence and metastasis rates and poor prognoses are the major challenges of current cancer therapy. Mounting evidence suggests that cancer stem cells (CSCs) play an important role in cancer development, chemoradiotherapy resistance, recurrence, and metastasis. Therefore, targeted CSC therapy has become a new strategy for solving the problems of cancer metastasis and recurrence. Since the properties of CSCs are regulated by the specific tumour microenvironment, the so-called CSC niche, which targets crosstalk between CSCs and their niches, is vital in our pursuit of new therapeutic opportunities to prevent cancer from recurring. In this review, we aim to highlight the factors within the CSC niche that have important roles in regulating CSC properties, including the extracellular matrix (ECM), stromal cells (e.g., associated macrophages (TAMs), cancer-associated fibroblasts (CAFs), and mesenchymal stem cells (MSCs)), and physiological changes (e.g., inflammation, hypoxia, and angiogenesis). We also discuss recent progress regarding therapies targeting CSCs and their niche to elucidate developments of more effective therapeutic strategies to eliminate cancer.

The roles of the SOX2 protein in the development of esophagus and esophageal squamous cell carcinoma, and pharmacological target for therapy

SOX2 is a transcription factor belonging to the SOX gene family, whose activity has been associated with the maintenance of the stemness and self-renewal of embryonic stem cells (ESCs), as well as the induction of differentiated cells into induced pluripotent stem cells (iPSCs). Moreover, accumulating studies have shown that SOX2 is amplified in various cancers, notably in esophageal squamous cell carcinoma (ESCC). In addition, SOX2 expression is linked to multiple malignant processes, including proliferation, migration, invasion, and drug resistance. Taken together, targeting SOX2 might shed light on novel approaches for cancer therapy. In this review, we aim to summarize the current knowledge regarding SOX2 in the development of esophagus and ESCC. We also highlight several therapeutic strategies for targeting SOX2 in different cancer types, which can provide new tools to treat cancers possessing abnormal levels of SOX2 protein.

Synthesis of Erythrocyte Nanodiscs for Bacterial Toxin Neutralization

Nanodiscs are a compelling nanomedicine platform due to their ultrasmall size and distinct disc shape. Current nanodisc formulations are made primarily with synthetic lipid bilayers and proteins. Here, we report a cellular nanodisc made with human red blood cell (RBC) membrane (denoted "RBC-ND") and show its effective neutralization against bacterial toxins. In vitro, RBC-ND neutralizes the hemolytic activity and cytotoxicity caused by purified α-toxin or complex whole secreted proteins (wSP) from methicillin-resistant Staphylococcus aureus bacteria. In vivo, RBC-ND confers significant survival benefits for mice intoxicated with α-toxin or wSP in both therapeutic and prevention regimens. Moreover, RBC-ND shows good biocompatibility and biosafety in vivo. Overall, RBC-ND distinguishes itself by inheriting the biological functions of the source cell membrane for bioactivity. The design strategy of RBC-ND can be generalized to other types of cell membranes for broad applications.