Inhibitory Effect of Multimodal Nanoassemblies against Glycative and Oxidative Stress in Cancer and Glycation Animal Models

Nanoassemblies loaded with low-dose paclitaxel can enhance the response of lung cancer immunotherapy by activating dendritic cells

Background

The immune tolerance of the tumor immune microenvironment (TIME) restricts the response to immune checkpoint inhibitors (ICIs). Targeted activation of dendritic cells (DCs) in the TIME seems to be a scheme for improving the therapeutic effect of ICIs treatment. The purpose of this study was to utilize nanotechnology to reprogram the immunosuppressive tumor immune microenvironment in situ, improving the response of ICIs to lung cancer.

Methods

In this study, a folic acid (FA)-modified nanoassembly (NA) loaded with low-dose paclitaxel (PTX) (FA-PTX NA), self-assembled by distearoylphosphatidylethanolamine-methoxy polyethylene glycol 2000-folic acid (DSPE-mPEG2000-FA) and PTX, was designed to reprogram the DC function of the TIME to sensitize cells to cancer immunotherapy. The characteristics of FA-PTX NAs were studied, and the cytotoxicity, cellular uptake, and DC stimulation of FA-PTX NAs were evaluated in vitro using a Lewis lung carcinoma (LLC) cell line and bone marrow-derived cells (BMDCs). Following this, the effect of the reprogrammed TIME and on the sensitization to immunotherapy in vivo were examined in a C57BL/6 mouse LLC subcutaneous xenograft model.

Results

The prepared FA-PTX NAs exhibited a slightly negative surface charge, appropriate size and shape, good drug release profiles, and high drug encapsulation efficiency and blood compatibility. The FA-PTX NAs were effectively uptaken by bone BMDCs, increasing the activation and expression of the costimulatory factor of BMDCs in vitro. In the LLC xenograft model treated with intravenous injection of FA-PTX NAs, the numbers of CD4+ and CD8+ T cells in the TIME increased significantly, the killing activity of tumor-specific cytotoxic T lymphocytes (CTLs) was significantly enhanced, and at the same time, the concentration of transforming growth factor β (TGF-β) decreased significantly. Furthermore, the infiltrated CD8+ T cells in TIME were mainly distributed in the tumor parenchyma. The combination of FA-PTX NAs and ICIs effectively inhibited the growth of LLC xenograft tumor, demonstrating a greater effect than that of ICIs alone. Moreover, it was found that apoptosis induction, increase in CD4+ and CD8+ T-cell infiltration, and improvement in the distribution of CD8+ T cells were involved in the anticancer mechanism of this combination treatment.

Conclusions

The NA loaded with low-dose PTX can reprogram the DC function in the TIME and exert a synergistic anticancer effect with ICIs in lung cancer treatment. Increased sensitization to ICI therapy as stimulated by PTX-enhanced NAs has potential applications in lung cancer immunotherapy.

Nano-therapeutics: The upcoming nanomedicine to treat cancer

Nanotechnology is considered a successful approach for cancer diagnosis and treatment. Preferentially, cancer cell recognition and drug targeting via nano-delivery system include the penetration of anticancer agents into the cell membrane to damage the cancer cell by protein modification, DNA oxidation, or mitochondrial dysfunction. The past research on nano-delivery systems and their target has proven the beneficial achievement in a malignant tumor. Modern perceptions using inventive nanomaterials for cancer management have been offered by a multifunctional platform based on various nano-carriers with the probability of imaging and cancer therapy simultaneously. Emerging nano-delivery systems in cancer therapy still lack knowledge of the biological functions behind the interaction between nanoparticles and cancer cells. Since the potential of engineered nanoparticles addresses the various challenges, limiting the success of cancer therapy subsequently, it is a must to review the molecular targeting of a nano-delivery system to enhance the therapeutic efficacy of cancer. This review focuses on using a nano-delivery system, an imaging system, and encapsulated nanoparticles for cancer therapy.

d-ribose-mediated glycation of fibrinogen: Role in the induction of adaptive immune response

A nonenzymatic reaction between reducing sugars and amino groups of proteins results in the formation of advanced glycation end products, which are linked to a number of chronic progressive diseases with macro- and microvascular complications. In this research, we sought to ascertain the immunological response to d-ibose-glycated fibrinogen. New Zealand White female rabbits were immunized with native and d-ribose-glycated (Rb-gly-Fb) fibrinogen and used for studying the immunological response. Serum from these rabbits analyzed using direct binding and competitive inhibition ELISA was found to contain a high titer of antibodies against Rb-gly-Fb; Rb-gly-Fb was much more immunogenic than its native form. The IgG against Rb-gly-Fb (Rb-gly-Fb-IgG) was highly specific against the immunogenic protein. Moreover, histopathology and immunofluorescence studies revealed the deposition of the Rb-gly-Fb-IgG immune complex in the glomerular basement membrane of the kidneys of immunized rabbits. Furthermore, immunization with Rb-gly-Fb increased the expression of genes encoding proinflammatory cytokines, tumour necrosis factor α, interleukin-6, interleukin-1β, and interferon-gamma, which is indicative of increased inflammation and the antigenic role of Rb-gly-Fb in provoking an immune response.

The role of non-enzymatic glycation on Tau-DNA interactions: Kinetic and mechanistic approaches

Despite the regulatory role of Tau protein in the stabilization and assembly of microtubules, this protein has an important function in the protection and stabilizing of DNA molecules in the cell nucleus. In the present study, it has been indicated that glycation of lysine residues (Lys-267, Lys-274, and Lys-280) in the microtubule-binding domain (MBD) can considerably decrease its binding affinity to DNA molecules. The structural analysis also confirmed that the decreased glycated tau-DNA complex's stability was due to structural modification of this protein after the glycation process. The study of hippocampal cells under hyperglycemic conditions showed that near to 70% of Tau proteins glycated in these cells, although the expression of Tau remained unaffected. The assessment of H3K9me2, as a marker for binding of Tau to pericentromeric heterochromatin (PCH), indicated that localization of Tau protein on PCH was remarkably decreased at high glucose conditions relative to the controls. It is suggested that increasing the structural stability of Tau protein limits the ability of this protein for DNA binding, while the molecular and physical barrier of glycated Lys residues should not be neglected.