Recent Advances in Nanoparticles-Based Platforms Targeting the PD-1/PD-L1 Pathway for Cancer Treatment

Wrecking neutrophil extracellular traps and antagonizing cancer-associated neurotransmitters by interpenetrating network hydrogels prevent postsurgical cancer relapse and metastases

Tumor-promoting niche after incomplete surgery resection (SR) can lead to more aggressive local progression and distant metastasis with augmented angiogenesis-immunosuppressive tumor microenvironment (TME). Herein, elevated neutrophil extracellular traps (NETs) and cancer-associated neurotransmitters (CANTs, e.g., catecholamines) are firstly identified as two of the dominant inducements. Further, an injectable fibrin-alginate hydrogel with high tissue adhesion has been constructed to specifically co-deliver NETs inhibitor (DNase I)-encapsulated PLGA nanoparticles and an unselective β-adrenergic receptor blocker (propranolol). The two components (i.e., fibrin and alginate) can respond to two triggers (thrombin and Ca2+, respectively) in postoperative bleeding to gelate, shaping into an interpenetrating network (IPN) featuring high strength. The continuous release of DNase I and PR can wreck NETs and antagonize catecholamines to decrease microvessel density, blockade myeloid-derived suppressor cells, secrete various proinflammatory cytokines, potentiate natural killer cell function and hamper cytotoxic T cell exhaustion. The reprogrammed TME significantly suppress locally residual and distant tumors, induce strong immune memory effects and thus inhibit lung metastasis. Thus, targetedly degrading NETs and blocking CANTs enabled by this in-situ IPN-based hydrogel drug depot provides a simple and efficient approach against SR-induced cancer recurrence and metastasis.

Construction of Immune Infiltration-Related LncRNA Signatures Based on Machine Learning for the Prognosis in Colon Cancer

Colon cancer is one of the malignant tumors with high morbidity, lethality, and prevalence across global human health. Molecular biomarkers play key roles in its prognosis. In particular, immune-related lncRNAs (IRL) have attracted enormous interest in diagnosis and treatment, but less is known about their potential functions. We aimed to investigate dysfunctional IRL and construct a risk model for improving the outcomes of patients. Nineteen immune cell types were collected for identifying house-keeping lncRNAs (HKLncRNA). GSE39582 and TCGA-COAD were treated as the discovery and validation datasets, respectively. Four machine learning algorithms (LASSO, Random Forest, Boruta, and Xgboost) and a Gaussian mixture model were utilized to mine the optimal combination of lncRNAs. Univariate and multivariate Cox regression was utilized to construct the risk score model. We distinguished the functional difference in an immune perspective between low- and high-risk cohorts calculated by this scoring system. Finally, we provided a nomogram. By leveraging the microarray, sequencing, and clinical data for immune cells and colon cancer patients, we identified the 221 HKLncRNAs with a low cell type-specificity index. Eighty-seven lncRNAs were up-regulated in the immune compared to cancer cells. Twelve lncRNAs were beneficial in improving performance. A risk score model with three lncRNAs (CYB561D2, LINC00638, and DANCR) was proposed with robust ROC performance on an independent dataset. According to immune-related analysis, the risk score is strongly associated with the tumor immune microenvironment. Our results emphasized IRL has the potential to be a powerful and effective therapy for enhancing the prognostic of colon cancer.

Synergistic Brilliance: Engineered Bacteria and Nanomedicine Unite in Cancer Therapy

Engineered bacteria are widely used in cancer treatment because live facultative/obligate anaerobes can selectively proliferate at tumor sites and reach hypoxic regions, thereby causing nutritional competition, enhancing immune responses, and producing anticancer microbial agents in situ to suppress tumor growth. Despite the unique advantages of bacteria-based cancer biotherapy, the insufficient treatment efficiency limits its application in the complete ablation of malignant tumors. The combination of nanomedicine and engineered bacteria has attracted increasing attention owing to their striking synergistic effects in cancer treatment. Engineered bacteria that function as natural vehicles can effectively deliver nanomedicines to tumor sites. Moreover, bacteria provide an opportunity to enhance nanomedicines by modulating the TME and producing substrates to support nanomedicine-mediated anticancer reactions. Nanomedicine exhibits excellent optical, magnetic, acoustic, and catalytic properties, and plays an important role in promoting bacteria-mediated biotherapies. The synergistic anticancer effects of engineered bacteria and nanomedicines in cancer therapy are comprehensively summarized in this review. Attention is paid not only to the fabrication of nanobiohybrid composites, but also to the interpromotion mechanism between engineered bacteria and nanomedicine in cancer therapy. Additionally, recent advances in engineered bacteria-synergized multimodal cancer therapies are highlighted.

SERS nanostructures with engineered active peptides against an immune checkpoint protein

The immune checkpoint programmed death ligand 1 (PD-L1) protein is expressed by tumor cells and it suppresses the killer activity of CD8+ T-lymphocyte cells binding to the programmed death 1 (PD-1) protein of these immune cells. Binding to either PD-L1 or PD1 is used for avoiding the inactivation of CD8+ T-lymphocyte cells. We report, for the first time, Au plasmonic nanostructures with surface-enhanced Raman scattering (SERS) properties (SERS nanostructures) and functionalized with an engineered peptide (CLP002: Trp-His-Arg-Ser-Tyr-Tyr-Thr-Trp-Asn-Leu-Asn-Thr), which targets PD-L1. Molecular dynamics calculations are used to describe the interaction of the targeting peptide with PD-L1 in the region where the interaction with PD-1 occurs, showing also the poor targeting activity of a peptide with the same amino acids, but a scrambled sequence. The results are confirmed experimentally since a very good targeting activity is observed against the MDA-MB-231 breast adenocarcinoma cancer cell line, which overexpresses PD-L1. A good activity is observed, in particular, for SERS nanostructures where the CLP002-engineered peptide is linked to the nanostructure surface with a short charged amino acid sequence and a long PEG chain. The results show that the functionalized SERS nanostructures show very good targeting of the immune checkpoint PD-L1.

Truncated PD1 Engineered Gas-Producing Extracellular Vesicles for Ultrasound Imaging and Subsequent Degradation of PDL1 in Tumor Cells

PDL1 blockade therapy holds great promise in cancer immunotherapy. Ultrasound imaging of PDL1 expression in the tumor is of great importance in predicting the therapeutic efficacy. As a proof-of-concept study, a novel ultrasound contrast agent has been innovated here to image and block PDL1 in the tumor tissue. Briefly, extracellular vesicles (EVs) are engineered to display truncated PD1 (tPD1) on the surface to bind PDL1 with high affinity by fusion to EV-abundant transmembrane protein PTGFRN. The engineered EVs are then encapsulated with Ca(HCO3)2 via electroporation and designated as Gp-EVtPD1, which would recognize PDL1 highly expressed cells and produce gas in the endosomes and lysosomes. On the one hand, the echogenic signal intensity correlates well with the PDL1 expression and immune response inhibition in the tumor. On the other hand, during the trajectory of Gp-EVtPD1 in the recipient cells, tPD1 on the EV binds PDL1 and triggers the PDL1 endocytosis and degradation in endosomes/lysosomes in a sequential manner, and thus boosts the anti-tumor immunity of cytotoxic T cells. In summary, Gp-EVtPD1 serves as a novel ultrasound contrast agent and blocker of PDL1, which might be of great advantage in imaging PDL1 expression and conquering immune checkpoint blocker resistance.

Immune checkpoint inhibitors promising role in cancer therapy: clinical evidence and immune-related adverse events

The advent of immune checkpoint inhibitors (ICIs) has led to noteworthy progressions in the management of diverse cancer types, as evidenced by the pioneering "ipilimumab" medication authorized by US FDA in 2011. Importantly, ICIs agents have demonstrated encouraging potential in bringing about transformation across diverse forms of cancer by selectively targeting the immune checkpoint pathways that are exploited by cancerous cells for dodging the immune system, culminating in progressive and favorable health outcomes for patients. The primary mechanism of action (MOA) of ICIs involves blocking inhibitory immune checkpoints. There are three approved categories including Programmed Death (PD-1) inhibitors (cemiplimab, nivolumab, and pembrolizumab), Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) (Ipilimumab), and Programmed Death-Ligand 1 (PDL-1) (Avelumab). Although ICIs promisingly increase therapeutic response and cancer survival rates, using ICIs has demonstrated some limitations including autoimmune reactions and toxicities, requiring close monitoring. The present review endeavors to explicate the underlying principles of the MOA and pharmacokinetics of the approved ICIs in the realm of cancer induction, including an appraisal of their level of practice-based evidence.

Macrophage-inherited exosome excise tumor immunosuppression to expedite immune-activated ferroptosis

BACKGROUND

Immunosuppressive tumor microenvironment (ITM) remains an obstacle that jeopardizes clinical immunotherapy.

METHODS

To address this concern, we have engineered an exosome inherited from M1-pheototype macrophages, which thereby retain functions and ingredients of the parent M1-phenotype macrophages. The delivered RSL3 that serves as a common ferroptosis inducer can reduce the levels of ferroptosis hallmarkers (eg, glutathione and glutathione peroxidase 4), break the redox homeostasis to magnify oxidative stress accumulation, promote the expression of ferroptosis-related proteins, and induce robust ferroptosis of tumor cells, accompanied with which systematic immune response activation can bbe realized. M1 macrophage-derived exosomes can inherit more functions and genetic substances than nanovesicles since nanovesicles inevitably suffer from substance and function loss caused by extrusion-arised structural damage.

RESULTS

Inspired by it, spontaneous homing to tumor and M2-like macrophage polarization into M1-like ones are attained, which not only significantly magnify oxidative stress but also mitigate ITM including M2-like macrophage polarization and regulatory T cell decrease, and regulate death pathways.

CONCLUSIONS

All these actions accomplish a synergistic antitumor enhancement against tumor progression, thus paving a general route to mitigate ITM, activate immune responses, and magnify ferroptosis.

Tumor Microenvironment Regulation and Cancer Targeting Therapy Based on Nanoparticles

Although we have made remarkable achievements in cancer awareness and medical technology, there are still tremendous increases in cancer incidence and mortality. However, most anti-tumor strategies, including immunotherapy, show low efficiency in clinical application. More and more evidence suggest that this low efficacy may be closely related to the immunosuppression of the tumor microenvironment (TME). The TME plays a significant role in tumorigenesis, development, and metastasis. Therefore, it is necessary to regulate the TME during antitumor therapy. Several strategies are developing to regulate the TME as inhibiting tumor angiogenesis, reversing tumor associated macrophage (TAM) phenotype, removing T cell immunosuppression, and so on. Among them, nanotechnology shows great potential for delivering regulators into TME, which further enhance the antitumor therapy efficacy. Properly designed nanomaterials can carry regulators and/or therapeutic agents to eligible locations or cells to trigger specific immune response and further kill tumor cells. Specifically, the designed nanoparticles could not only directly reverse the primary TME immunosuppression, but also induce effective systemic immune response, which would prevent niche formation before metastasis and inhibit tumor recurrence. In this review, we summarized the development of nanoparticles (NPs) for anti-cancer therapy, TME regulation, and tumor metastasis inhibition. We also discussed the prospect and potential of nanocarriers for cancer therapy.

Recent Trends and Opportunities for the Targeted Immuno-Nanomaterials for Cancer Theranostics Applications

The targeted delivery of cancer immunotherapies has increased noticeably in recent years. Recent advancements in immunotherapy, particularly in blocking the immune checkpoints (ICs) axis, have shown favorable treatment outcomes for multiple types of cancer including melanoma and non-small-cell lung cancer (NSLC). Engineered micromachines, including microparticles, and nanoplatforms (organic and inorganic), functionalized with immune agonists can effectively deliver immune-targeting molecules to solid tumors. This review focuses on the nanomaterial-based strategies that have shown promise in identifying and targeting various immunological markers in the tumor microenvironment (TME) for cancer diagnosis and therapy. Nanomaterials-based cancer immunotherapy has improved treatment outcomes by triggering an immune response in the TME. Evaluating the expression levels of ICs in the TME also could potentially aid in diagnosing patients who would respond to IC blockade therapy. Detecting immunological checkpoints in the TME using noninvasive imaging systems via tailored nanosensors improves the identification of patient outcomes in immuno-oncology (IO). To enhance patient-specific analysis, lab-on-chip (LOC) technology is a rapid, cost-effective, and accurate way of recapitulating the TME. Such novel nanomaterial-based technologies have been of great interest for testing immunotherapies and assessing biomarkers. Finally, we provide a perspective on the developments in artificial intelligence tools to facilitate ICs-based nano theranostics toward cancer immunotherapy.

Clinical updates on tyrosine kinase inhibitors in HER2-positive breast cancer

Breast cancer (BC) is caused by epigenetic modifications and genetic heterogeneity and exhibits various histological feature. HER2+ (Human epidermal growth factor receptor 2) is a more aggressive type of breast cancer, diagnosis and prognosis are difficult for HER2+ BC. Anti-HER2+ inhibitors have been effectively used for patient treatment. High mortality rate is reported in HER2+ BC, due to availability of limited therapeutic options. Despite advances in systemic medications to treat metastatic breast cancer (MBC), HER2-positive MBC is still challenging for patients and treating clinicians. The clinical characteristics of the disease have changed after treatment with HER2-targeted therapy. Various types of Tyrosine kinase inhibitors (TKIs) have been developed to treat patients with HER2+ BC including afatinib, lapatinib, neratinib, tucatinib, and pyrotinib, have been developed as HER2-targeted therapies. The antibody-drug conjugates adotrastuzumab, emtansine, famtrastuzumab, and deruxtecan, as well as the anti-HER2 monoclonal antibody pertuzumab are used in both early-stage and metastatic situations, either alone or in conjunction with chemotherapy and other HER2-targeting therapies. The emergence of drug resistance in anti-HER2 therapies has been observed. To overcome drug resistance and limited efficacy in current treatment options, nano formulations can be used in patients with HER2+ BC treatment. Anti-HER2 ligands can be used in various nano formulations to target HER2 receptors. Here we will discuss, targeted TKIs in patients with HER2+ BC, clinical studies of HER2+ targeted TKIs, mechanisms of resistance to HER2-directed therapies with new implications of TKIs in HER2+ MBC (metastatic breast cancer) and anti-HER2 ligand in various nano formulations to target HER2 receptors.