Aptamer-Functionalized Nanoparticles Mediate PD-L1 siRNA Delivery for Effective Gene Silencing in Triple-Negative Breast Cancer Cells

Using aptamers for targeted delivery of RNA therapies

RNA-based treatments that can silence, introduce, or restore gene expression to target human diseases are emerging as a new class of therapeutics. Despite their potential for use in broad applications, their clinical translation has been hampered by a need for delivery to specific cells and tissues. Cell targeting based on the use of aptamers provides an approach for improving their delivery to the desired sites of action. Aptamers are nucleic acid oligonucleotides with structural conformations that provide a robust capacity for the recognition of cell surface molecules and that can be used for directed targeting. Aptamers can be directly conjugated to therapeutic RNA molecules, in the form of aptamer-oligonucleotide chimeras, or incorporated into nanoparticles used as vehicles for the delivery of these therapeutics. Herein, we discuss the use of aptamers for cell-directed RNA therapies, provide an overview of different types of aptamer-targeting RNA therapeutics, and review examples of their therapeutic applications. Challenges associated with manufacturing and scaling up production, and key considerations for their clinical implementation, are also outlined.

Targeted nanodelivery systems for personalized cancer therapy

Conventional cancer therapies such as chemotherapy face challenges such as poor tumor targeting, systemic toxicity, and drug resistance. Nanotechnology offers solutions through advanced drug delivery systems that preferentially accumulate in tumors while avoiding healthy tissues. Recent innovations have enabled the optimization of engineered nanocarriers for extended circulation and tumor localization via both passive and active targeting mechanisms. Passive accumulation exploits the leaky vasculature of tumors, whereas active strategies use ligands to selectively bind cancer cell receptors. Multifunctional nanoparticles also allow the combination of imaging, multiple therapeutic modalities and on-demand drug release within a single platform. Overall, precisely tailored nanotherapeutics that leverage unique pathophysiological traits of malignancies provide opportunities to overcome the limitations of traditional treatment regimens. This emerging field promises more effective and personalized nanomedicine approaches to detect and treat cancer. The key aspects highlighted in this review include the biological barriers associated with nanoparticles, rational design principles to optimize nanocarrier pharmacokinetics and tumor uptake, passive and active targeting strategies, multifunctionality, and reversal of multidrug resistance.

A novel therapeutic approach targeting PD-L1 in HNSCC and bone marrow-derived mesenchymal stem cells hampers pro-metastatic features in vitro: perspectives for blocking tumor-stroma communication and signaling

BACKGROUND

Current conventional treatment regimens for head and neck squamous cell carcinoma (HNSCC), are poorly effective because of the emergence of resistance mechanisms. Many studies have reported how the tumor microenvironment influences tumor response to immune checkpoint inhibitors targeting PD-1/PD-L1. It has been reported that overexpression of PD-L1 correlates with and is involved in cancer progression by promoting epithelial-to-mesenchymal-transition (EMT) program, stemness and tumor cell invasiveness through AKT and MAPK pathways. In this study, we investigated how bone marrow mesenchymal stem cells (BM-MSCs) recruited and educated by HNSCC cells are able to promote tumor cell invasion and EMT program. In addition, we analyzed how the crosstalk between stromal cells and tumor cells can affect PD-L1 expression levels. In this context, we developed and characterized a novel anti-PD-L1 recombinant Fab (rFab') and tested its ability to potentiate the effect of cisplatin.

METHODS

BM-MSCs and HNSCC cells co-cultures, cell migration and invasion were performed using Boyden chambers. The effect of treatments on cell viability and growth were analyzed by MTT and clonogenic assay, respectively. The anti-PD-L1 rFab' was prepared in E. Coli and tested for its binding on HNSCC cells and BM-MSCs by FACS analysis and fluorescence microscopy. PD-L1, p-AKT, p-ERK, N-cadherin and β-catenin expression levels were analyzed by western blotting.

RESULTS

BM-MSCs were induced by tumor cells to migrate, invade and to trans-differentiate in cancer associated fibroblasts (CAFs) as demonstrated by increased expression levels of α-SMA and FAP-α. BM-MSCs contributed to HNSCC invasiveness by increasing p-AKT, p-ERK, N-cadherin and β-catenin expression levels. When BM-MSCs and HNSCC cells were co-cultured the level of PD-L1 expression was enhanced in both cells indicating a reciprocal support in favoring tumor aggressiveness. Tumor cell treatment with rFab' anti-PD-L1 reduced their viability, growth, migration and invasion and blunted the underlying signaling pathways. In addition, rFab' anti-PD-L1 was able to potentiate the antitumor effect of cisplatin on HNSCC cells.

CONCLUSIONS

BM-MSCs recruited and educated by HNSCC cells support tumor cell aggressiveness via PD-L1. A novel rFab' anti-PD-L1 reduces HNSCC proliferation, migration and invasion and potentiates the cisplatin effect suggesting its potential to be conjugated with drugs for immuno-cytotoxic therapy.

Targeting breast tumor extracellular matrix and stroma utilizing nanoparticles

Breast cancer is a complicated malignancy and is known as the most common cancer in women. Considerable experiments have been devoted to explore the basic impacts of the tumor stroma, particularly the extracellular matrix (ECM) and stromal components, on tumor growth and resistance to treatment. ECM is made up of an intricate system of proteins, glycosaminoglycans, and proteoglycans, and maintains structural support and controls key signaling pathways involved in breast tumors. ECM can block different drugs such as chemotherapy and immunotherapy drugs from entering the tumor stroma. Furthermore, the stromal elements, such as cancer-associated fibroblasts (CAFs), immune cells, and blood vessels, have crucial impacts on tumor development and therapeutic resistance. Recently, promising outcomes have been achieved in using nanotechnology for delivering drugs to tumor stroma and crossing ECM in breast malignancies. Nanoparticles have various benefits for targeting the breast tumor stroma, such as improved permeability and retention, extended circulation time, and the ability to actively target the area. This review covers the latest developments in nanoparticle therapies that focus on breast tumor ECM and stroma. We will explore different approaches using nanoparticles to target the delivery of anticancer drugs like chemotherapy, small molecule drugs, various antitumor products, and other specific synthetic therapeutic agents to the breast tumor stroma. Furthermore, we will investigate the utilization of nanoparticles in altering the stromal elements, such as reprogramming CAFs and immune cells, and also remodeling ECM.

Nanomedicine for cancer patient-centered care

Cancer is a leading cause of morbidity and mortality worldwide, and an increase in incidence is estimated in the next future, due to population aging, which requires the development of highly tolerable and low-toxicity cancer treatment strategies. The use of nanotechnology to tailor treatments according to the genetic and immunophenotypic characteristics of a patient's tumor, and to allow its targeted release, can meet this need, improving the efficacy of treatment and minimizing side effects. Nanomedicine-based approach for the diagnosis and treatment of cancer is a rapidly evolving field. Several nanoformulations are currently in clinical trials, and some have been approved and marketed. However, their large-scale production and use are still hindered by an in-depth debate involving ethics, intellectual property, safety and health concerns, technical issues, and costs. Here, we survey the key approaches, with specific reference to organ-on chip technology, and cutting-edge tools, such as CRISPR/Cas9 genome editing, through which nanosystems can meet the needs for personalized diagnostics and therapy in cancer patients. An update is provided on the nanopharmaceuticals approved and marketed for cancer therapy and those currently undergoing clinical trials. Finally, we discuss the emerging avenues in the field and the challenges to be overcome for the transfer of nano-based precision oncology into clinical daily life.

Recent advancements in small interfering RNA based therapeutic approach on breast cancer

Breast cancer (BC) is the most common and malignant tumor diagnosed in women, with 2.9 million cases in 2023 and the fifth highest cancer-causing mortality worldwide. Recent developments in targeted therapy options for BC have demonstrated the promising potential of small interfering RNA (siRNA)-based cancer therapeutic approaches. As BC continues to be a global burden, siRNA therapy emerges as a potential treatment strategy to regulate disease-related genes in other types of cancers, including BC. siRNAs are tiny RNA molecules that, by preventing their expression, can specifically silence genes linked to the development of cancer. In order to increase the stability and effectiveness of siRNA delivery to BC cells, minimize off-target effects, and improve treatment efficacy, advanced delivery technologies such as lipid nanoparticles and nanocarriers have been created. Additionally, combination therapies, such as siRNAs that target multiple pathways are used in conjunction with conventional chemotherapy agents, have shown synergistic effects in various preclinical studies, opening up new treatment options for breast cancer that are personalized and precision medicine-oriented. Targeting important genes linked to BC growth, metastasis, and chemo-resistance has been reported in BC research using siRNA-based therapies. This study reviews recent reports on therapeutic approaches to siRNA for advanced treatment of BC. Furthermore, this review evaluates the role and mechanisms of siRNA in BC and demonstrates the potential of exploiting siRNA as a novel target for BC therapy.

The use of nanomaterials as drug delivery systems and anticancer agents in the treatment of triple-negative breast cancer: an updated review (year 2005 to date)

Triple-negative breast cancer (TNBC) is characterised by the lack or low expression of estrogen, progesterone, and human epidermal growth factor receptor 2 receptors. TNBC has a high recurrence rate, swiftly metastasizes, and has a high mortality rate. Subsequently, the increase in cases of TNBC has signaled the need for treatment strategies with improved drug delivery systems. New diagnostic approaches, chemical entities, formulations particular those in the nanometric range have emerged after extensive scientific research as alternative strategies for TNBC treatment. As compared to contemporary cancer therapy, nanoparticles offer peculiar tunable features namely small size, shape, electrical charge, magnetic and fluorescent properties. Specifically in targeted drug delivery, nanoparticles have been demonstrated to be highly efficient in encapsulating, functionalization, and conjugation. Presently, nanoparticles have ignited and transformed the approach in photodynamic therapy, bioimaging, use of theranostics and precision medicine delivery in breast cancer. Correspondingly, recent years have witnessed a drastic rise in literature pertaining to treatment of TNBC using nanomaterials. Subsequently, this manuscript aims to present a state-of-the-art of nanomaterials advance on TNBC treatment; the ubiquitous utility use of nanomaterials such as liposomes, dendrimers, solid lipid nanomaterials, gold nanomaterials and quantum dots as anticancer agents and drug delivery systems in TNBC.

Clinical Advances in Triple Negative Breast Cancer Treatment: Focus on Poly (L-lactide-coglycolide) Nanoparticles

Triple negative breast cancer (TNBC) is the most aggressive type of breast cancer and is associated with high probability of metastasis and poor prognosis. Chemotherapeutics and surgery remain the most common options for TNBC patients; however, chemotherapeutic resistance and relapse of tumors limit the progression free survival and patient life span. This review provides an overview of recent chemotherapeutics that are in clinical trial, and the combination of drugs that are being investigated to overcome the drug resistance and to improve patient survival in different molecular subtypes of TNBCs. Nanotherapeutics have emerged as a promising platform for TNBC treatment and aim to improve the selectivity and solubility of drugs, reduce systemic side effects, and overcome multi-drug resistance. The study explores the role of nanoparticles for TNBC treatment and summarizes the types of nanoparticles that are in clinical trials. Poly(L-lactide-co-glycolide) (PLGA) is the most studied polymeric carrier for drug delivery and for TNBC treatment in research and in clinics. This review is about providing recent advancements in PLGA nanotherapeutic formulations and their application to help treat TNBC. Some background on current chemotherapies and pathway inhibitors is provided so that the readers are aware of what is currently considered for TNBC. Some of the pathway inhibitors may also be of importance for nanotherapeutics development. SIGNIFICANCE STATEMENT: This minireview summarizes the progress on chemotherapeutics and nanoparticle delivery for treatment of TNBC and specifically highlights the lead compounds that are in clinical trials.

Recent Progress of Multifunctional Molecular Probes for Triple-Negative Breast Cancer Theranostics

Breast cancer (BC) poses a significant threat to women's health, with triple-negative breast cancer (TNBC) representing one of the most challenging and aggressive subtypes due to the lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression. Traditional TNBC treatments often encounter issues such as low drug efficiency, limited tumor enrichment, and substantial side effects. Therefore, it is crucial to explore novel diagnostic and treatment systems for TNBC. Multifunctional molecular probes (MMPs), which integrate target recognition as well as diagnostic and therapeutic functions, introduce advanced molecular tools for TNBC theranostics. Using an MMP system, molecular drugs can be precisely delivered to the tumor site through a targeted ligand. Real-time dynamic monitoring of drug release achieved using imaging technology allows for the evaluation of drug enrichment at the tumor site. This approach enables accurate drug release, thereby improving the therapeutic effect. Therefore, this review summarizes the recent advancements in MMPs for TNBC theranostics, encompassing the design and synthesis of MMPs as well as their applications in the field of TNBC theranostics.

Advancing cancer immunotherapy through siRNA-based gene silencing for immune checkpoint blockade

Cancer immunotherapy represents a revolutionary strategy, leveraging the patient's immune system to inhibit tumor growth and alleviate the immunosuppressive effects of the tumor microenvironment (TME). The recent emergence of immune checkpoint blockade (ICB) therapies, particularly following the first approval of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors like ipilimumab, has led to significant growth in cancer immunotherapy. The extensive explorations on diverse immune checkpoint antibodies have broadened the therapeutic scope for various malignancies. However, the clinical response to these antibody-based ICB therapies remains limited, with less than 15% responsiveness and notable adverse effects in some patients. This review introduces the emerging strategies to overcome current limitations of antibody-based ICB therapies, mainly focusing on the development of small interfering ribonucleic acid (siRNA)-based ICB therapies and innovative delivery systems. We firstly highlight the diverse target immune checkpoint genes for siRNA-based ICB therapies, incorporating silencing of multiple genes to boost anti-tumor immune responses. Subsequently, we discuss improvements in siRNA delivery systems, enhanced by various nanocarriers, aimed at overcoming siRNA's clinical challenges such as vulnerability to enzymatic degradation, inadequate pharmacokinetics, and possible unintended target interactions. Additionally, the review presents various combination therapies that integrate chemotherapy, phototherapy, stimulatory checkpoints, ICB antibodies, and cancer vaccines. The important point is that when used in combination with siRNA-based ICB therapy, the synergistic effect of traditional therapies is strengthened, improving host immune surveillance and therapeutic outcomes. Conclusively, we discuss the insights into innovative and effective cancer immunotherapeutic strategies based on RNA interference (RNAi) technology utilizing siRNA and nanocarriers as a novel approach in ICB cancer immunotherapy.

Aptamers as an approach to targeted cancer therapy

Conventional cancer treatments can cause serious side effects because they are not specific to cancer cells and can damage healthy cells. Aptamers often are single-stranded oligonucleotides arranged in a unique architecture, allowing them to bind specifically to target sites. This feature makes them an ideal choice for targeted therapeutics. They are typically produced through the systematic evolution of ligands by exponential enrichment (SELEX) and undergo extensive pharmacological revision to modify their affinity, specificity, and therapeutic half-life. Aptamers can act as drugs themselves, directly inhibiting tumor cells. Alternatively, they can be used in targeted drug delivery systems to transport drugs directly to tumor cells, minimizing toxicity to healthy cells. In this review, we will discuss the latest and most advanced approaches to using aptamers for cancer treatment, particularly targeted therapy overcoming resistance to conventional therapies.

Nanomedicine-Based Drug-Targeting in Breast Cancer: Pharmacokinetics, Clinical Progress, and Challenges

Breast cancer (BC) is a malignant neoplasm that begins in the breast tissue. After skin cancer, BC is the second most common type of cancer in women. At the end of 2040, the number of newly diagnosed BC cases is projected to increase by over 40%, reaching approximately 3 million worldwide annually. The hormonal and chemotherapeutic approaches based on conventional formulations have inappropriate therapeutic effects and suboptimal pharmacokinetic responses with nonspecific targeting actions. To overcome such issues, the use of nanomedicines, including liposomes, nanoparticles, micelles, hybrid nanoparticles, etc., has gained wider attention in the treatment of BC. Smaller dimensional nanomedicine (especially 50-200 nm) exhibited improved in vivo effectiveness, such as better tissue penetration and more effective tumor suppression through enhanced retention and permeation, as well as active targeting of the drug. Additionally, nanotechnology, which further extended and developed theranostic nanomedicine by incorporating diagnostic and imaging agents in one platform, has been applied to BC. Furthermore, hybrid and theranostic nanomedicine has also been explored for gene delivery as anticancer therapeutics in BC. Moreover, the nanocarriers' size, shape, surface charge, chemical compositions, and surface area play an important role in the nanocarriers' stability, cellular absorption, cytotoxicity, cellular uptake, and toxicity. Additionally, nanomedicine clinical translation for managing BC remains a slow process. However, a few cases are being used clinically, and their progress with the current challenges is addressed in this Review. Therefore, this Review extensively discusses recent advancements in nanomedicine and its clinical challenges in BC.

Recent Advances of Multifunctional PLGA Nanocarriers in the Management of Triple-Negative Breast Cancer

Even though chemotherapy stands as a standard option in the therapy of TNBC, problems associated with it such as anemia, bone marrow suppression, immune suppression, toxic effects on healthy cells, and multi-drug resistance (MDR) can compromise their effects. Nanoparticles gained paramount importance in overcoming the limitations of conventional chemotherapy. Among the various options, nanotechnology has appeared as a promising path in preclinical and clinical studies for early diagnosis of primary tumors and metastases and destroying tumor cells. PLGA has been extensively studied amongst various materials used for the preparation of nanocarriers for anticancer drug delivery and adjuvant therapy because of their capability of higher encapsulation, easy surface functionalization, increased stability, protection of drugs from degradation versatility, biocompatibility, and biodegradability. Furthermore, this review also provides an overview of PLGA-based nanoparticles including hybrid nanoparticles such as the inorganic PLGA nanoparticles, lipid-coated PLGA nanoparticles, cell membrane-coated PLGA nanoparticles, hydrogels, exosomes, and nanofibers. The effects of all these systems in various in vitro and in vivo models of TNBC were explained thus pointing PLGA-based NPs as a strategy for the management of TNBC.

Hyaluronic acid-empowered nanotheranostics in breast and lung cancers therapy

Nanomedicine application in cancer therapy is an urgency because of inability of current biological therapies for complete removal of tumor cells. The development of smart and novel nanoplatforms for treatment of cancer can provide new insight in tumor suppression. Hyaluronic acid is a biopolymer that can be employed for synthesis of smart nanostructures capable of selective targeting CD44-overexpressing tumor cells. The breast and lung cancers are among the most malignant and common tumors in both females and males that environmental factors, lifestyle and genomic alterations are among the risk factors for their pathogenesis and development. Since etiology of breast and lung tumors is not certain and multiple factors participate in their development, preventative measures have not been completely successful and studies have focused on developing new treatment strategies for them. The aim of current review is to provide a comprehensive discussion about application of hyaluronic acid-based nanostructures for treatment of breast and lung cancers. The main reason of using hyaluronic acid-based nanoparticles is their ability in targeting breast and lung cancers in a selective way due to upregulation of CD44 receptor on their surface. Moreover, nanocarriers developed from hyaluronic acid or functionalized with hyaluronic acid have high biocompatibility and their safety is appreciated. The drugs and genes used for treatment of breast and lung cancers lack specific accumulation at cancer site and their cytotoxicity is low, but hyaluronic acid-based nanostructures provide their targeted delivery to tumor site and by increasing internalization of drugs and genes in breast and lung tumor cells, they improve their therapeutic index. Furthermore, hyaluronic acid-based nanostructures can be used for phototherapy-mediated breast and lung cancers ablation. The stimuli-responsive and smart kinds of hyaluronic acid-based nanostructures such as pH- and light-responsive can increase selective targeting of breast and lung cancers.

Nano-immunotherapy: overcoming delivery challenge of immune checkpoint therapy

Immune checkpoint (ICP) molecules expressed on tumor cells can suppress immune responses against tumors. ICP therapy promotes anti-tumor immune responses by targeting inhibitory and stimulatory pathways of immune cells like T cells and dendritic cells (DC). The investigation into the combination therapies through novel immune checkpoint inhibitors (ICIs) has been limited due to immune-related adverse events (irAEs), low response rate, and lack of optimal strategy for combinatorial cancer immunotherapy (IMT). Nanoparticles (NPs) have emerged as powerful tools to promote multidisciplinary cooperation. The feasibility and efficacy of targeted delivery of ICIs using NPs overcome the primary barrier, improve therapeutic efficacy, and provide a rationale for more clinical investigations. Likewise, NPs can conjugate or encapsulate ICIs, including antibodies, RNAs, and small molecule inhibitors. Therefore, combining the drug delivery system (DDS) with ICP therapy could provide a profitable immunotherapeutic strategy for cancer treatment. This article reviews the significant NPs with controlled DDS using current data from clinical and pre-clinical trials on mono- and combination IMT to overcome ICP therapeutic limitations.

Aptamers Targeting the PD-1/PD-L1 Axis: A Perspective

Aptamers have emerged in recent years as alternatives to antibodies or small molecules to interfere with the immune check points by blocking the PD-1/PD-L1 interactions and represent an interesting perspective for immuno-oncology. Aptamers are RNA or DNA nucleotides able to bind to a target with high affinity, with the target ranging from small molecules to proteins and up to cells. Aptamers are identified by the SELEX method that can be modified for specific purposes. The range of applications of aptamers covers therapy as well as new alternative assay technologies similar to ELISA. Aptamers' limited plasma stability can be managed using delivery strategies. The goal of this Perspective is to give an overview of the current development of aptamers targeting the most studied immune checkpoint modulators, PD-1 and PD-L1, and analogous strategies with aptamers for other immuno-related targets.

Aptamers against cancer drug resistance: Small fighters switching tactics in the face of defeat

Discovering novel cancer therapies has attracted extreme interest in the last decade. In this regard, multidrug resistance (MDR) to chemotherapies is a key challenge in cancer treatment. Cancerous cells are growingly become resistant to existing chemotherapeutics by employing diverse mechanisms, highlighting the significance of discovering approaches to overcome MDR. One promising strategy is utilizing aptamers as unique tools to target elements or signaling pathways incorporated in resistance mechanisms, or develop actively targeted drug delivery systems or chimeras enabling the precise delivery of novel agents to inhibit the conventionally undruggable resistance elements. Furthermore, due to their advantages over their proteinaceous counterparts, particularly antibodies, including improved targeting action, enhanced thermal stability, easier production, and superior tumor penetration, aptamers are emerging and have frequently been considered for developing cancer therapeutics. Here, we highlighted significant chemoresistance pathways in cancer and discussed the use of aptamers as prospective tools to surmount cancer MDR.

Tissue Inhibitor of Metalloproteinases-1 Overexpression Mediates Chemoresistance in Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is among the most aggressive breast cancer subtypes. Despite being initially responsive to chemotherapy, patients develop drug-resistant and metastatic tumors. Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a secreted protein with a tumor suppressor function due to its anti-proteolytic activity. Nevertheless, evidence indicates that TIMP-1 binds to the CD63 receptor and activates noncanonical oncogenic signaling in several cancers, but its role in mediating TNBC chemoresistance is still largely unexplored. Here, we show that mesenchymal-like TNBC cells express TIMP-1, whose levels are further increased in cells generated to be resistant to cisplatin (Cis-Pt-R) and doxorubicin (Dox-R). Moreover, public dataset analyses indicate that high TIMP-1 levels are associated with a worse prognosis in TNBC subjected to chemotherapy. Knock-down of TIMP-1 in both Cis-Pt-R and Dox-R cells reverses their resistance by inhibiting AKT activation. Consistently, TNBC cells exposed to recombinant TIMP-1 or TIMP-1-enriched media from chemoresistant cells, acquire resistance to both cisplatin and doxorubicin. Importantly, released TIMP-1 reassociates with plasma membrane by binding to CD63 and, in the absence of CD63 expression, TIMP-1-mediated chemoresistance is blocked. Thus, our results identify TIMP-1 as a new biomarker of TNBC chemoresistance and lay the groundwork for evaluating whether blockade of TIMP-1 signal is a viable treatment strategy.

New Biomarkers and Treatment Advances in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a specific subtype of breast cancer lacking hormone receptor expression and HER2 gene amplification. TNBC represents a heterogeneous subtype of breast cancer, characterized by poor prognosis, high invasiveness, high metastatic potential, and a tendency to relapse. In this review, the specific molecular subtypes and pathological aspects of triple-negative breast cancer are illustrated, with particular attention to the biomarker characteristics of TNBC, namely: regulators of cell proliferation and migration and angiogenesis, apoptosis-regulating proteins, regulators of DNA damage response, immune checkpoints, and epigenetic modifications. This paper also focuses on omics approaches to exploring TNBC, such as genomics to identify cancer-specific mutations, epigenomics to identify altered epigenetic landscapes in cancer cells, and transcriptomics to explore differential mRNA and protein expression. Moreover, updated neoadjuvant treatments for TNBC are also mentioned, underlining the role of immunotherapy and novel and targeted agents in the treatment of TNBC.

Organic Nanodelivery Systems as a New Platform in the Management of Breast Cancer: A Comprehensive Review from Preclinical to Clinical Studies

Breast cancer accounts for approximately 25% of cancer cases and 16.5% of cancer deaths in women, and the World Health Organization predicts that the number of new cases will increase by almost 70% over the next two decades, mainly due to an ageing population. Effective diagnostic and treatment strategies are, therefore, urgently required for improving cure rates among patients since current therapeutic modalities have many limitations and side effects. Nanomedicine is evolving as a promising approach for cancer management, including breast cancer, and various types of organic and inorganic nanomaterials have been investigated for their role in breast cancer diagnosis and treatment. Following an overview on breast cancer characteristics and pathogenesis and challenges of the current treatment strategies, the therapeutic potential of biocompatible organic-based nanoparticles such as liposomes and polymeric micelles that have been tested in breast cancer models are reviewed. The efficacies of different drug delivery and targeting strategies are documented, ranging from synthetic to cell-derived nanoformulations together with a summary of the interaction of nanoparticles with externally applied energy such as radiotherapy. The clinical translation of nanoformulations for breast cancer treatment is summarized including those undergoing clinical trials.

Aptamer-Based Strategies to Boost Immunotherapy in TNBC

The immune system (IS) may play a crucial role in preventing tumor development and progression, leading, over the last years, to the development of effective cancer immunotherapies. Nevertheless, immune evasion, the capability of tumors to circumvent destructive host immunity, remains one of the main obstacles to overcome for maximizing treatment success. In this context, promising strategies aimed at reshaping the tumor immune microenvironment and promoting antitumor immunity are rapidly emerging. Triple-negative breast cancer (TNBC), an aggressive breast cancer subtype with poor outcomes, is highly immunogenic, suggesting immunotherapy is a viable strategy. As evidence of this, already, two immunotherapies have recently become the standard of care for patients with PD-L1 expressing tumors, which, however, represent a low percentage of patients, making more active immunotherapeutic approaches necessary. Aptamers are short, highly structured, single-stranded oligonucleotides that bind to their protein targets at high affinity and specificity. They are used for therapeutic purposes in the same way as monoclonal antibodies; thus, various aptamer-based strategies are being actively explored to stimulate the IS’s response against cancer cells. The aim of this review is to discuss the potential of the recently reported aptamer-based approaches to boost the IS to fight TNBC.

Application of aptamer-drug delivery system in the therapy of breast cancer

Despite significant treatment advances, breast cancer remains the leading cause of cancer death in women. From the current treatment situation, in addition to developing chemoresistant tumours, distant organ metastasis, and recurrences, patients with breast cancer often have a poor prognosis. Aptamers as "chemical antibodies" may be a way to resolve this dilemma. Aptamers are single-stranded, non-coding oligonucleotides (DNA or RNA), resulting their many advantages, including stability for long-term storage, simplicity of synthesis and function, and low immunogenicity, a high degree of specificity and antidote. Aptamers have gained popularity as a method for diagnosing and treating specific tumors in recent years. This article introduces the application of ten different aptamer delivery systems in the treatment and diagnosis of breast cancer, and systematically reviews their latest research progress in breast cancer treatment and diagnosis. It provides a new direction for the clinical treatment of breast cancer.

Breast Cancer: From Pathophysiology to Novel Therapeutic Approaches 2.0

Breast cancer (BC) is the most common malignancy in women worldwide [...].