M2pep-Modified Cyclodextrin-siRNA Nanoparticles Modulate the Immunosuppressive Tumor Microenvironment for Prostate Cancer Therapy

Harnessing the human microbiome and its impact on immuno-oncology and nanotechnology for next-generation cancer therapies

The integration of microbiome research and nanotechnology represents a significant advancement in immuno-oncology, potentially improving the effectiveness of cancer immunotherapies. Recent studies highlight the influential role of the human microbiome in modulating immune responses, presenting new opportunities to enhance immune checkpoint inhibitors (ICIs) and other cancer therapies. Nanotechnology offers precise drug delivery and immune modulation capabilities, minimizing off-target effects while maximizing therapeutic outcomes. This review consolidates current knowledge on the interactions between the microbiome and the immune system, emphasizing the microbiome's impact on ICIs, and explores the incorporation of nanotechnology in cancer treatment strategies. Additionally, it provides a forward-looking perspective on the synergistic potential of microbiome modulation and nanotechnology to overcome existing challenges in immuno-oncology. This integrated approach may enhance the personalization and effectiveness of next-generation cancer treatments, paving the way for transformative patient care.

Cyclodextrins as non-viral vectors in cancer theranostics: A review

Cancer ranks as the top cause of death following cardiovascular diseases. Identifying cancer patients at early stages presents significant challenges due to the asymptomatic nature of early-stage tumors. Conversely, the advancement of therapy resistance has led to a reduction in cancer treatment efficacy. Consequently, utilizing nanoparticles for the diagnosis and treatment of cancer can greatly enhance the prognosis and results for patients. CDs are recognized entities in the pharmaceutical domain and have been extensively used for therapeutic purposes in disease treatment. These non-viral vectors have shown efficacy in inhibiting both solid tumors and hematological malignancies through targeted drug delivery. CDs can enhance the administration of medications and genes in cancer treatment by ensuring their continuous release. The stimuli-responsive CDs have enhanced the targeted delivery of payloads at the tumor location, responding to the stimuli in TME such as pH, redox and light. CDs can serve as effective carriers that enhance the efficacy of phototherapy by improving the solubility and delivery of phototherapeutic agents, enabling integration with chemotherapy and immunotherapy. The administration of immunomodulators through CDs can enhance cancer immunotherapy and boost the infiltration of immune cells. Ultimately, CDs can aid in cancer diagnosis and the identification of biomarkers.

A subtype specific probe for targeted magnetic resonance imaging of M2 tumor-associated macrophages in brain tumors

Pro-tumoral M2 tumor-associated macrophages (TAMs) play a critical role in the tumor immune microenvironment (TIME), making them an important therapeutic target for cancer treatment. Approaches for imaging and monitoring M2 TAMs, as well as tracking their changes in response to tumor progression or treatment are highly sought-after but remain underdeveloped. Here, we report an M2-targeted magnetic resonance imaging (MRI) probe based on sub-5 nm ultrafine iron oxide nanoparticles (uIONP), featuring an anti-biofouling coating to prevent non-specific macrophage uptake and an M2-specific peptide ligand (M2pep) for active targeting of M2 TAMs. The targeting specificity of M2pep-uIONP was validated in vitro, using M0, M1, and M2 macrophages, and in vivo, using an orthotopic patient-tissue-derived xenograft (PDX) mouse model of glioblastoma (GBM). MRI of the mice revealed hypointense contrast in T2-weighted images of intracranial tumors 24 h after receiving intravenous (i.v.) injection of M2pep-uIONP. In contrast, no noticeable contrast change was observed in mice receiving scrambled-sequence M2pep-conjugated uIONP (scM2pep-uIONP) or the commercially available iron oxide nanoparticle formulation, Ferumoxytol. Measurement of nanoparticle-induced T2 value changes in tumors showed 38 %, 9 %, and 2 % decrease for M2pep-uIONP, scM2pep-uIONP, and Ferumoxytol, respectively. Moreover, M2pep-uIONP exhibited 88.7-fold higher intra-tumoral accumulation compared to co-injected Ferumoxytol at 24 h post-injection. Immunofluorescence-stained tumor sections showed that CD68+/CD163+ M2 TAMs were highly co-localized with Cy7-M2pep-uIONP, but not with Cy7-scM2pep-uIONP and Cy7-Ferumoxytol. Flow cytometry analysis revealed 26 ± 10 % of M2 TAMs were targeted by M2pep-uIONP, which was significantly higher than Ferumoxytol (16 ± 1 %) and scM2pep-uIONP (13 ± 4 %) with the same dosage (20 mg Fe/kg). These findings demonstrate that M2pep-uIONP functions as a ligand-mediated MRI probe for targeted imaging of M2 TAMs in GBM, with potential applications for imaging of M2 TAM in other cancer types. STATEMENT OF SIGNIFICANCE: Targeting the pro-tumoral M2 subtype of tumor-associated macrophages (TAMs) to modulate the tumor immune microenvironment (TIME) is an emerging strategy for developing novel cancer therapies and enhancing the efficacy of existing treatments. In this study, we have developed a magnetic resonance imaging (MRI) probe using sub-5 nm ultrafine iron oxide nanoparticles (uIONP), which are coated with an anti-biofouling polymer and conjugated to an M2-specific peptide ligand (M2pep). Our results demonstrate that M2pep-uIONP exhibits an 88.7-fold higher accumulation in intracranial tumors in an orthotopic patient-derived xenograft (PDX) model of glioblastoma compared to the commercial iron oxide nanoparticle, Ferumoxytol. This enhanced accumulation enables M2pep-uIONP to induce significant MRI contrast, providing a non-invasive imaging tool to visualize M2 TAMs and monitor changes in the TIME of brain tumors and potentially other cancers.

Unleashing the power of peptides in prostate cancer immunotherapy: mechanism, facts and perspectives

Prostate cancer, the second most common cancer in men, often progresses to castration-resistant prostate cancer despite androgen deprivation therapy. Immunotherapy, revolutionary in cancer treatment, has limited efficacy in prostate cancer due to its "cold tumor" nature. Peptides, with unique advantages, offer new hope. This review explores how peptide-based tumor immunotherapy can transform prostate cancer from a "cold" to a "hot" state. It modulates the immunosuppressive tumor microenvironment by regulating non-immune cells (such as cancer-associated fibroblasts, endothelial cells, and adipose stromal cells), repolarizing tumor-associated macrophages, activating NK cells, and tuning cytokines. Additionally, peptides can induce immunogenic cell death (ICD) in prostate cancer cells through ferroptosis, pyroptosis, and autophagy modulation. The review also revisits existing prostate cancer immunotherapies, including immune checkpoint blockade, CAR T cell therapy, and dendritic cell vaccines, highlighting how peptides can enhance their effectiveness and safety. Finally, two peptide-based immunotherapy strategies in the development stage, peptide-integrated Proteolysis-Targeting Chimera therapy and peptide-involved epigenomic therapy, are introduced, showing great potential for future prostate cancer treatment.

Chitosan-based nanoarchitectures for siRNA delivery in cancer therapy: A review of pre-clinical and clinical importance

The gene therapy has been developed into a new cancer treatment option. Now that we know which molecular components contribute to carcinogenesis, we may use gene therapy to target particular signalling pathways in cancer treatment. Problems with gene therapy include genetic tool degradation in blood, off-targeting features, and inadequate tumor site accumulation; new delivery mechanisms are needed to address these issues. A polysaccharide made from chitin, chitosan has found extensive use in the creation of nanoparticles. The delivery of genes in the treatment of illnesses, particularly cancer, has made use of nanostructures modified with chitosan. Topics covered in this review center on cancer treatment using chitosan-based polymers for siRNA delivery. This study aims to assess the potential of chitosan nanoparticles for the simultaneous administration of siRNA and anti-cancer medications. In cancer treatment, these nanoparticles can transport phytochemicals or chemotherapeutics together with siRNA. In addition, chitosan nanoparticles loaded with siRNA can inhibit the growth and spread of human malignancies by delivering siRNA that targets particular genes. Chitosan nanoparticles loaded with siRNA can heighten the responsiveness of cancer cells. Future therapeutic applications of chitosan nanoparticles may open the path for cancer treatment, thanks to their biocompatibility and biosafety.

Insights into CSF-1R Expression in the Tumor Microenvironment

The colony-stimulating factor 1 receptor (CSF-1R) plays a pivotal role in orchestrating cellular interactions within the tumor microenvironment (TME). Although the CSF-1R has been extensively studied in myeloid cells, the expression of this receptor and its emerging role in other cell types in the TME need to be further analyzed. This review explores the multifaceted functions of the CSF-1R across various TME cellular populations, including tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), dendritic cells (DCs), cancer-associated fibroblasts (CAFs), endothelial cells (ECs), and cancer stem cells (CSCs). The activation of the CSF-1R by its ligands, colony-stimulating factor 1 (CSF-1) and Interleukin-34 (IL-34), regulates TAM polarization towards an immunosuppressive M2 phenotype, promoting tumor progression and immune evasion. Similarly, CSF-1R signaling influences MDSCs to exert immunosuppressive functions, hindering anti-tumor immunity. In DCs, the CSF-1R alters antigen-presenting capabilities, compromising immune surveillance against cancer cells. CSF-1R expression in CAFs and ECs regulates immune modulation, angiogenesis, and immune cell trafficking within the TME, fostering a pro-tumorigenic milieu. Notably, the CSF-1R in CSCs contributes to tumor aggressiveness and therapeutic resistance through interactions with TAMs and the modulation of stemness features. Understanding the diverse roles of the CSF-1R in the TME underscores its potential as a therapeutic target for cancer treatment, aiming at disrupting pro-tumorigenic cellular crosstalk and enhancing anti-tumor immune responses.

Advances in and prospects of immunotherapy for prostate cancer

Immunotherapy has shown promising therapeutic effects in hematological malignancies and certain solid tumors and has emerged as a critical and highly potential treatment modality for cancer. However, prostate cancer falls under the category of immune-resistant cold tumors, for which immunotherapy exhibits limited efficacy in patients with solid tumors. Thus, it is important to gain a deeper understanding of the tumor microenvironment in prostate cancer to facilitate immune system activation and overcome immune suppression to advance immunotherapy for prostate cancer. In this review, we discuss the immunosuppressive microenvironment of prostate cancer, which is characterized by the presence of few tumor-infiltrating lymphocytes, abundant immunosuppressive cells, low immunogenicity, and a noninflammatory phenotype, which significantly influences the efficacy of immunotherapy for prostate cancer. Immunotherapy is mainly achieved by activating the host immune system and overcoming immunosuppression. In this regard, we summarize the therapeutic advances in immune checkpoint blockade, immunogenic cell death, reversal of the immunosuppressive tumor microenvironment, tumor vaccines, immune adjuvants, chimeric antigen receptor T-cell therapy, and overcoming penetration barriers in prostate cancer, with the aim of providing novel research insights and approaches to enhance the effectiveness of immunotherapy for prostate cancer.

Enhancing cancer immunotherapy: Nanotechnology-mediated immunotherapy overcoming immunosuppression

Immunotherapy is an important cancer treatment method that offers hope for curing cancer patients. While immunotherapy has achieved initial success, a major obstacle to its widespread adoption is the inability to benefit the majority of patients. The success or failure of immunotherapy is closely linked to the tumor's immune microenvironment. Recently, there has been significant attention on strategies to regulate the tumor immune microenvironment in order to stimulate anti-tumor immune responses in cancer immunotherapy. The distinctive physical properties and design flexibility of nanomedicines have been extensively utilized to target immune cells (including tumor-associated macrophages (TAMs), T cells, myeloid-derived suppressor cells (MDSCs), and tumor-associated fibroblasts (TAFs)), offering promising advancements in cancer immunotherapy. In this article, we have reviewed treatment strategies aimed at targeting various immune cells to regulate the tumor immune microenvironment. The focus is on cancer immunotherapy models that are based on nanomedicines, with the goal of inducing or enhancing anti-tumor immune responses to improve immunotherapy. It is worth noting that combining cancer immunotherapy with other treatments, such as chemotherapy, radiotherapy, and photodynamic therapy, can maximize the therapeutic effects. Finally, we have identified the challenges that nanotechnology-mediated immunotherapy needs to overcome in order to design more effective nanosystems.

The Many Faces of Cyclodextrins within Self-Assembling Polymer Nanovehicles: From Inclusion Complexes to Valuable Structural and Functional Elements

Most chemotherapeutic agents are poorly soluble in water, have low selectivity, and cannot reach the tumor in the desired therapeutic concentration. On the other hand, sensitive hydrophilic therapeutics like nucleic acids and proteins suffer from poor bioavailability and cell internalization. To solve this problem, new types of controlled release systems based on nano-sized self-assemblies of cyclodextrins able to control the speed, timing, and location of therapeutic release are being developed. Cyclodextrins are macrocyclic oligosaccharides characterized by a high synthetic plasticity and potential for derivatization. Introduction of new hydrophobic and/or hydrophilic domains and/or formation of nano-assemblies with therapeutic load extends the use of CDs beyond the tried-and-tested CD-drug host-guest inclusion complexes. The recent advances in nano drug delivery have indicated the benefits of the hybrid amphiphilic CD nanosystems over individual CD and polymer components. This review provides a comprehensive overview of the most recent advances in the design of CDs self-assemblies and their use for delivery of a wide range of therapeutic molecules. It aims to offer a valuable insight into the many roles of CDs within this class of drug nanocarriers as well as current challenges and future perspectives.

Non-Coding RNA in Tumor Cells and Tumor-Associated Myeloid Cells-Function and Therapeutic Potential

The RNA world is wide, and besides mRNA, there is a variety of other RNA types, such as non-coding (nc)RNAs, which harbor various intracellular regulatory functions. This review focuses on small interfering (si)RNA and micro (mi)RNA, which form a complex network regulating mRNA translation and, consequently, gene expression. In fact, these RNAs are critically involved in the function and phenotype of all cells in the human body, including malignant cells. In cancer, the two main targets for therapy are dysregulated cancer cells and dysfunctional immune cells. To exploit the potential of mi- or siRNA therapeutics in cancer therapy, a profound understanding of the regulatory mechanisms of RNAs and following targeted intervention is needed to re-program cancer cells and immune cell functions in vivo. The first part focuses on the function of less well-known RNAs, including siRNA and miRNA, and presents RNA-based technologies. In the second part, the therapeutic potential of these technologies in treating cancer is discussed, with particular attention on manipulating tumor-associated immune cells, especially tumor-associated myeloid cells.