Nanoparticle-Mediated Delivery of STAT3 Inhibitors in the Treatment of Lung Cancer

Combination therapy with immune checkpoint inhibitors in colorectal cancer: Challenges, resistance mechanisms, and the role of microbiota

Colorectal cancer (CRC) is still one of the leading causes of cancer deaths worldwide. Even though there has been progress in cancer immunotherapy, the results of applying immune checkpoint inhibitors (ICIs) have been unsatisfactory, especially in microsatellite stable (MSS) CRC. Single-agent ICIs that target programmed cell death-1 (PD-1)/ PD-L1, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T cell Ig- and mucin-domain-containing molecule-3 (TIM-3), and lymphocyte activation gene (LAG)-3 have emerged as having specific benefits. However, many primary and secondary resistance mechanisms are available in the tumor microenvironment (TME) that prevent it from happening. Combination strategies, such as the use of anti-PD-1 and anti-CTLA-4, can be effective in overcoming these resistance pathways, but toxicities remain a significant concern. Moreover, ICIs have been integrated with various treatment modalities, including chemotherapy, radiotherapy, antibiotics, virotherapy, polyadenosine diphosphate-ribose polymerase (PARP) inhibitors, and heat shock protein 90 (HSP90) inhibitors. The outcomes observed in both preclinical and clinical settings have been encouraging. Interestingly, manipulating gut microbiota via fecal microbiota transplantation (FMT) has been identified as a new strategy to increase the efficacy of immunotherapy in CRC patients. Therefore, integrating ICIs with other treatment approaches holds promise in enhancing the prognosis of CRC patients. This review focuses on the unmet need for new biomarkers to select patients for combination therapies and the ongoing work to overcome resistance and immune checkpoint blockade.

STAT3 Signaling Pathway in Health and Disease

Signal transducer and activator of transcription 3 (STAT3) is a critical transcription factor involved in multiple physiological and pathological processes. While STAT3 plays an essential role in homeostasis, its persistent activation has been implicated in the pathogenesis of various diseases, particularly cancer, bone-related diseases, autoimmune disorders, inflammatory diseases, cardiovascular diseases, and neurodegenerative conditions. The interleukin-6/Janus kinase (JAK)/STAT3 signaling axis is central to STAT3 activation, influencing tumor microenvironment remodeling, angiogenesis, immune evasion, and therapy resistance. Despite extensive research, the precise mechanisms underlying dysregulated STAT3 signaling in disease progression remain incompletely understood, and no United States Food and Drug Administration (USFDA)-approved direct STAT3 inhibitors currently exist. This review provides a comprehensive evaluation of STAT3's role in health and disease, emphasizing its involvement in cancer stem cell maintenance, metastasis, inflammation, and drug resistance. We systematically discuss therapeutic strategies, including JAK inhibitors (tofacitinib, ruxolitinib), Src Homology 2 domain inhibitors (S3I-201, STATTIC), antisense oligonucleotides (AZD9150), and nanomedicine-based drug delivery systems, which enhance specificity and bioavailability while reducing toxicity. By integrating molecular mechanisms, disease pathology, and emerging therapeutic interventions, this review fills a critical knowledge gap in STAT3-targeted therapy. Our insights into STAT3 signaling crosstalk, epigenetic regulation, and resistance mechanisms offer a foundation for developing next-generation STAT3 inhibitors with greater clinical efficacy and translational potential.

Single-cell multi-omics analysis reveals the mechanism of action of a novel antioxidant polyphenol nanoparticle loaded with STAT3 agonist in mediating cardiomyocyte ferroptosis to ameliorate age-related heart failure

BACKGROUND

Heart failure (HF) is a prevalent and critical cardiac condition that leads to profound structural and functional changes in the heart. Although traditional treatments have shown partial efficacy, the long-term outcomes remain suboptimal. Emerging research has highlighted the pivotal role of oxidative stress and ferroptosis in HF progression. This study investigates a new therapeutic approach utilizing antioxidant polyphenol nanoparticles loaded with a STAT3 agonist (PN@Col) to target these pathways and improve age-related HF.

RESULTS

Key cells and genes contributing to HF progression were identified via analysis of the GEO database, with single-cell RNA sequencing (scRNA-seq) and AUCell analysis used to evaluate differential gene expression. The STAT3 gene was highlighted as essential, and its functionality was further validated in vitro through cell experiments, confirming its impact on cardiomyocytes (CMs) in HF. Following the development of PN@Col, in vitro experiments showed that PN@Col effectively reduced oxidative stress and ferroptosis in CMs. In vivo studies in elderly HF mice demonstrated significant improvements in cardiac function following PN@Col treatment.

CONCLUSIONS

PN@Col offers a promising therapeutic approach to age-related HF by mitigating oxidative stress and ferroptosis in cardiomyocytes. These findings provide a solid scientific foundation for PN@Col as a potential novel treatment strategy for HF, supporting further exploration toward clinical application.

Inorganic Nanoparticle Functionalization Strategies in Immunotherapeutic Applications

Nanotechnology has been increasingly utilized in anticancer treatment owing to its ability of engineering functional nanocarriers that enhance therapeutic effectiveness while minimizing adverse effects. Inorganic nanoparticles (INPs) are prevalent nanocarriers to be customized for a wide range of anticancer applications, including theranostics, imaging, targeted drug delivery, and therapeutics, because they are advantageous for their superior biocompatibility, unique optical properties, and capacity of being modified via versatile surface functionalization strategies. In the past decades, the high adaptation of INPs in this emerging immunotherapeutic field makes them good carrier options for tumor immunotherapy and combination immunotherapy. Tumor immunotherapy requires targeted delivery of immunomodulating therapeutics to tumor locations or immunological organs to provoke immune cells and induce tumor-specific immune response while regulating immune homeostasis, particularly switching the tumor immunosuppressive microenvironment. This review explores various INP designs and formulations, and their employment in tumor immunotherapy and combination immunotherapy. We also introduce detailed demonstrations of utilizing surface engineering tactics to create multifunctional INPs. The generated INPs demonstrate the abilities of stimulating and enhancing the immune response, specific targeting, and regulating cancer cells, immune cells, and their resident microenvironment, sometimes along with imaging and tracking capabilities, implying their potential in multitasking immunotherapy. Furthermore, we discuss the promises of INP-based combination immunotherapy in tumor treatments.

Enhancing cancer therapy: The role of drug delivery systems in STAT3 inhibitor efficacy and safety

The signal transducer and activator of transcription 3 (STAT3), a member of the STAT family, resides in the nucleus to regulate genes essential for vital cellular functions, including survival, proliferation, self-renewal, angiogenesis, and immune response. However, continuous STAT3 activation in tumor cells promotes their initiation, progression, and metastasis, rendering STAT3 pathway inhibitors a promising avenue for cancer therapy. Nonetheless, these inhibitors frequently encounter challenges such as cytotoxicity and suboptimal biocompatibility in clinical trials. A viable strategy to mitigate these issues involves delivering STAT3 inhibitors via drug delivery systems (DDSs). This review delineates the regulatory mechanisms of the STAT3 signaling pathway and its association with cancer. It offers a comprehensive overview of the current application of DDSs for anti-STAT3 inhibitors and investigates the role of DDSs in cancer treatment. The conclusion posits that DDSs for anti-STAT3 inhibitors exhibit enhanced efficacy and reduced adverse effects in tumor therapy compared to anti-STAT3 inhibitors alone. This paper aims to provide an outline of the ongoing research and future prospects of DDSs for STAT3 inhibitors. Additionally, it presents our insights on the merits and future outlook of DDSs in cancer treatment.

Applications and advancements of nanoparticle-based drug delivery in alleviating lung cancer and chronic obstructive pulmonary disease

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are among the leading causes of mortality worldwide. Cigarette smoking is among the main aetiologic factors for both ailments. These diseases share common pathogenetic mechanisms including inflammation, oxidative stress, and tissue remodelling. Current therapeutic approaches are limited by low efficacy and adverse effects. Consequentially, LC has a 5-year survival of < 20%, while COPD is incurable, underlining the necessity for innovative treatment strategies. Two promising emerging classes of therapy against these diseases include plant-derived molecules (phytoceuticals) and nucleic acid-based therapies. The clinical application of both is limited by issues including poor solubility, poor permeability, and, in the case of nucleic acids, susceptibility to enzymatic degradation, large size, and electrostatic charge density. Nanoparticle-based advanced drug delivery systems are currently being explored as flexible systems allowing to overcome these limitations. In this review, an updated summary of the most recent studies using nanoparticle-based advanced drug delivery systems to improve the delivery of nucleic acids and phytoceuticals for the treatment of LC and COPD is provided. This review highlights the enormous relevance of these delivery systems as tools that are set to facilitate the clinical application of novel categories of therapeutics with poor pharmacokinetic properties.

Efficient polymeric nanoparticles for RNAi in macrophage reveal complex effects on polarization markers upon knockdown of STAT3/STAT6

Tumor associated macrophages (TAMs) are the most abundant immune cell type in the tissue microenvironment, affecting tumor progression, metastasis and therapeutic response. Different macrophage activation ("polarization") states can be distinguished: resting (M0; non-activated), pro-inflammatory/anti-tumorigenic (M1) and anti-inflammatory/pro-tumorigenic (M2). When exploring macrophages as targets in novel cancer immunotherapy approaches, TAM repolarization from the M2 into the M1 phenotype is an intriguing strategy to block their pro-tumoral and enhance their anti-tumoral properties. In the context of RNAi-based gene knockdown of M2 promoting genes, major bottlenecks include cellular siRNA delivery and correct intracellular processing. This is particularly true in case of macrophages as a cell type well-known to be notoriously hard-to-transfect. Among polymeric nanocarriers, the cationic polymer polyethylenimine (PEI) is widely explored for delivering nucleic acids. Further advanced nanocarriers are tyrosine-modified polymers based on PEI or polypropylenimine dendrimers (PPI) for highly efficient siRNA delivery in vitro and in vivo. In this paper, we explored a panel of PEI- or PPI-based nanoparticle systems for siRNA-mediated gene knockdown efficacy in macrophages and subsequent TAM repolarization. The tyrosine-modified linear 10 kDa PEI (LP10Y) or branched 5 kDa PEI (P5Y) as well as a tyrosine-modified PPI (PPI-Y) were found most efficient for gene knockdown in macrophage cell lines or primary macrophages, independent of their polarization. Knockdown of STAT6 or STAT3 led to repolarization of M2 macrophages, as indicated by alterations in various M2 and M1 marker levels. This highly specific approach also demonstrated non-redundant functions of STAT3 and STAT6. Importantly, macrophage re-polarization from M2 to M1 upon PPI-Y/siRNA-mediated STAT6 knockdown increased tumor cell phagocytosis in a co-culture model. In conclusion, we identify certain tyrosine-modified PEI- or PPI-based nanoparticles as particularly efficient for macrophage transfection, and the specific, siRNA-mediated STAT6 knockdown as a promising approach for macrophage repolarization and enhancement of their tumor cell suppressive role.

Mendelian randomization combined with multi-omics explores the relationship between heart failure and cancer

Background: Whether there is an association between HF (HF) and cancer has not been conclusively established, and it is not clear whether patients with cancer can share similar hospitalization strategies and outcomes with patients with HF. Methods: Genome-wide association summary statistics were performed using a two-sample Mendelian randomization (MR) method for HF patients and cancer patients from the GWAS directory, with co-localization and Summary Data-Based Mendelian Randomization (SMR) analyses to identify HF-associated genes, and transcriptomic analyses to analyze the roles of these genes in the clinical diagnosis and targeted therapies of multiple cancer types. Results: Two-sample MR analysis showed that increased risk of HF was associated with decreased risk of cervical, brain, breast, colorectal, lung, and skin cancers, and co-localization combined with SMR analysis identified ABO and SURF1 as HF-associated genes, and transcriptomic analyses showed that ABO is a risk factor for HF and a protective factor against cancer, whereas SURF1 is a protective factor against HF and a protective factor against cancer. Conclusion: There was no causal relationship between heart failure and cancers (Cervical, brain, breast, colorectal, lung and skin cancers) risk factors, however there was a trend toward a negative causal relationship between heart failure and cancers (Cervical, brain, breast, colorectal, lung and skin cancers) occurrence.

Transitional Insight into the RNA-Based Oligonucleotides in Cancer Treatment

Conventional cancer therapies with chemodrugs suffer from various disadvantages, such as irreversible side effects on the skin, heart, liver, and nerves with even fatal consequences. RNA-based therapeutic is a novel technology which offers great potential as non-toxic, non-infectious, and well-tolerable platform. Herein, we introduce different RNA-based platforms with a special focus on siRNA, miRNA, and mRNA applications in cancer treatment in order to better understand the details of their therapeutic effects. Of note, the co-delivery of RNAs with other distinct RNA or drugs has provided safe, efficient, and novel treatment modalities for cancer treatment.

Advances and challenges in the treatment of lung cancer

Lung cancer accounts for a relatively high proportion of malignant tumors. As the most prevalent type of lung cancer, non-small cell lung cancer (NSCLC) is characterized by high morbidity and mortality. Presently, the arsenal of treatment strategies encompasses surgical resection, chemotherapy, targeted therapy and radiotherapy. However, despite these options, the prognosis remains distressingly poor with a low 5-year survival rate. Therefore, it is urgent to pursue a paradigm shift in treatment methodologies. In recent years, the advent of sophisticated biotechnologies and interdisciplinary integration has provided innovative approaches for the treatment of lung cancer. This article reviews the cutting-edge developments in the nano drug delivery system, molecular targeted treatment system, photothermal treatment strategy, and immunotherapy for lung cancer. Overall, by systematically summarizing and critically analyzing the latest progress and current challenges in these treatment strategies of lung cancer, we aim to provide a theoretical basis for the development of novel drugs for lung cancer treatment, and thus improve the therapeutic outcomes for lung cancer patients.

KDF1 Promoted Proliferation, Migration and Invasion of Lung Adenocarcinoma Cells through Activating STAT3 and AKT Pathway

KDF1 has been reported to be correlated with carcinogenesis. However, its role and mechanism are far from clear. To explore the possible role and underlying mechanism of KDF1 in lung adenocarcinoma (LUAD), we investigated KDF1 expression in LUAD tissues and the influence of KDF1 in the phenotype of LUAD cells (A549 and PC-9) as well as the underlying mechanism. Compared to non-tumor lung epithelial cells, KDF1 was upregulated in the cancer cells of the majority of LUAD patients, and its expression was correlated with tumor size. Patients with enhanced KDF1 in cancer cells (compared with paired adjacent non-neoplastic lung epithelial cells) had shorter overall survival than patients with no increased KDF1 in cancer cells. Knockdown of KDF1 inhibited the migration, proliferation and invasion of LUAD cells in vitro. And overexpression of KDF1 increased the growth of the subcutaneous tumors in mice. In terms of molecular mechanisms, overexpression of KDF1 induced the expression of AKT, p-AKT and p-STAT3. In KDF1-overexpressing A549 cells, inhibition of the STAT3 pathway decreased the level of AKT and p-AKT, whereas inhibition of the AKT pathway had no effect on the activation of STAT3. Inhibition of STAT3 or AKT pathways reversed the promoting effects of KDF1 overexpression on the LUAD cell phenotype and STAT3 inhibition appeared to have a better effect. Finally, in the cancer cells of LUAD tumor samples, the KDF1 level was observed to correlate positively with the level of p-STAT3. All these findings suggest that KDF1, which activates STAT3 and the downstream AKT pathway in LUAD, acts as a tumor-promoting factor and may represent a therapeutic target.