Tumor Microenvironment Responsive RNA Drug Delivery Systems: Intelligent Platforms for Sophisticated Release.

Cancer is a significant health concern, increasingly showing insensitivity to traditional treatments, highlighting the urgent need for safer and more practical treatment options. Ribonucleic acid (RNA) gene therapy drugs have demonstrated promising potential in preclinical and clinical trials for antitumor therapy by regulating tumor-related gene expression. However, RNA's poor membrane permeability and stability restrict its effectiveness in entering and being utilized in cells. An appropriate delivery system is crucial for achieving targeted tumor effects. The tumor microenvironment (TME), characterized by acidity, hypoxia, enzyme overexpression, elevated glutathione (GSH) concentration, and excessive reactive oxygen species (ROS), is essential for tumor survival. Furthermore, these distinctive features can also be harnessed to develop intelligent drug delivery systems. Various nanocarriers that respond to the TME have been designed for RNA drug delivery, showing the advantages of tumor targeting and low toxicity. This Review discusses the abnormal changes of components in TME, therapeutic RNAs' roles, underlying mechanisms, and the latest developments in utilizing vectors that respond to microenvironments for treating tumors. We hope it provides insight into creating and optimizing RNA delivery vectors to improve their effectiveness.

The formation mechanism and homeostasis of extrachromosomal DNA.

Extrachromosomal DNA, referred to as extrachromosomal DNA (ecDNA), was found in most cancers and nearly absent in normal cells. The properties of ecDNA enable tumor cells to be more responsive to various environments. The non-Mendelian genetic mechanism of ecDNA could arouse increasing tumor heterogeneity. Besides, ecDNA would promote tumor invasiveness and provide resistance mechanisms associated with poorer survival consequences. Furthermore, ecDNA could profoundly impact oncogene activation, genome instability, tumor heterogeneity, etc. Consequently, they may offer potential possibilities for tumor diagnosis and therapeutics. We primarily reviewed the classification, several primary formation mechanisms, homeostasis maintenance and frontier progress of ecDNA and late emphasized its fundamental roles in tumorigenesis and put forward some new insights.

MiR-26a-5p regulates proliferation, apoptosis, migration and invasion via inhibiting hydroxysteroid dehydrogenase like-2 in cervical cancer cell.

BACKGROUND: Evidences have indicated that miR-26a-5p regulates the malignant properties of various tumor cells. However, the influences of miR-26a-5p on proliferation, apoptosis and invasion are still vague in the cervical cancer (CC) cells. METHODS: The miRNA microarray and real-time quantitative PCR (RT-qPCR) analysis were utilized to detect the expression of miR-26a-5p in the patients with CC. Kaplan-Meier plotter was performed to evaluate the overall survival (OS) of the patients with CC. The CCK-8, flow cytometry, transwell and wound healing analyses were respectively used to analyze proliferation, migration and invasion in the CC cells. RT-qPCR, western blot and IHC analysis were executed to measure the expression of hydroxysteroid dehydrogenase like-2 (HSDL2) in the patients with CC. Bioinformatics and luciferase reporter assay were carried out to verify the relationship of miR-26a-5p and HSDL2. RESULTS: The expression of miR-26a-5p was downregulated and low expression of miR-26a-5p indicated a poor OS in patients with CC. Overexpression of miR-26a-5p significantly inhibited proliferation, migration and invasion, accelerated apoptosis in the Hela and C33A cells. The expression of HSDL2 was upregulated, and negatively correlated with miR-26a-5p in the patients with CC. HSDL2 was directly targeted by miR-26a-5p and rescue experiments displayed that HSDL2 partially abolished proliferation, apoptosis, migration, and invasion induced by miR-26a-5p in CC cells. CONCLUSIONS: MiR-26a-5p alleviated progression of CC by suppressing proliferation, migration and invasion, promoting apoptosis through downregulating HSDL2.

Progress on the role of extrachromosomal DNA in tumor pathogenesis and evolution.

The amplification of oncogenes on extrachromosomal DNA (ecDNA) provides a new mechanism for cancer cells to adapt to the changes in the tumor microenvironment and accelerate tumor evolution. These extrachromosomal elements contain oncogenes, and their chromatin structures are more open than linear chromosomes and therefore have stronger oncogene transcriptional activity. ecDNA always contains enhancer elements, and genes on ecDNA can be reintegrated into the linear genome to regulate the selective expression of genes. ecDNA lacks centromeres, and the inheritance from the parent cell to the daughter cell is uneven. This non-Mendelian genetic mechanism results in the increase of tumor heterogeneity with daughter cells that can gain a competitive advantage through a large number of copies of oncogenes. ecDNA promotes tumor invasiveness and provides a mechanism for drug resistance associated with poorer survival outcomes. Recent studies have demonstrated that the overall proportion of ecDNA in tumors is approximately 40%. In this review, we summarize the current knowledge of ecDNA in the field of tumorigenesis and development.

Selection and identification of novel peptides specifically targeting human cervical cancer.

Cervical cancer is the second most commonly diagnosed cancer and the third leading cause of cancer deaths among females in underdeveloped countries. This study aimed to identify several novel cervical cancer-specific targeting peptides (CSPs) to provide new methods for the effective diagnosis and treatment of cervical cancer. Peptide library screening in vivo was performed on human cervical cancer xenografts with Ph.D.™-12 and C7C phage display peptide libraries. Two specific peptide sequences (GDALFSVPLEVY and KQNLAEG), which were enriched in tumors, were screened, and respectively, named CSP-GD and CSP-KQ through three rounds of biopanning. The in vivo tumor-targeting ability of these peptides was identified by injecting them into mice with cervical cancer xenograft. CSPs were compounded and labeled with fluorescein isothiocyanate (FITC). The specificity and affinity of FITC-CSPs were evaluated in human cervical cancer cell lines and tissue microarrays in vitro by immunofluorescent staining. Results showed that FITC-CSP-GD and FITC-CSP-KQ evidently and specifically bound to the cell membrane and cytoplasm of SiHa, ME-180, and C-33A cells in vitro. In human cervical cancer tissue, FITC-CSP-GD and FITC-CSP-KQ strongly targeted human cervical adenocarcinoma and cervical squamous cell carcinoma tissues, respectively. A bright FITC signal was located mainly on the cell membrane and cytoplasm of tumor cells. In conclusion, the novel 12-residue peptide CSP-GD and 7-residue peptide CSP-KQ could specifically target human cervical cancer and may have the potential to be used in the diagnosis and targeted therapy of cervical cancer.

Antitumor activity of Polygonatum sibiricum polysaccharides.

Cancer is a global public health problem. Natural polysaccharides have been shown to enhance the effectiveness of cancer treatments. Polygonatum sibiricum (PS) has been used for millennia to treat diverse diseases. PS comprises numerous active constituents, including saponins, peptides, volatile oils, polysaccharides, and lectins. Many studies have highlighted the crucial role of polysaccharides in PS. Modern studies have shown that Polygonatum sibiricum polysaccharide (PSP) exhibits diverse pharmacological activities, including immunomodulatory, antitumor, antioxidant, and anti-aging effects. However, further study of the antitumor mechanisms is difficult because the activities of PSP are closely associated with its complex structural features and the different molecular weights of its components. Therefore, this review focuses on the research background and the extraction and purification of PSP. Studies related to the mechanism of the antitumor effects of PSP constituents of different molecular weights are also summarized, and perspectives on PSP research are presented.

Carrier-free nanoparticles based on self-assembly of 5-FU and copper-genistein complexes for the combined treatment of hepatocellular carcinoma.

5-Fluorouracil (5-FU) is commonly used as a chemotherapeutic drug for advanced HCC. However, the effectiveness of 5-FU is limited by the emergence of resistance and poor targeting efficiency. Combining 5-FU with natural compounds has shown promise in HCC treatment. In this study, we prepared carrier-free nanoparticles (GEN-Cu-GEN@FUA) containing 5-FU and genistein (GEN) in a synergistic ratio via a green synthesis procedure. The resulting GEN-Cu-GEN@FUA nanoparticles had a spherical or near spherical shape, a dynamic size of 129.3 ± 40.1 nm, and a high drug loading content of approximately 21.40% (5-FU) and 61.48% (GEN). These nanoparticles exhibited approximately 3.6-fold lower IC50 value than 5-FU alone in Bel-7402 cells and resulted in a 3.7-fold greater reduction in tumor weight compared to 5-FU alone in Bel-7402 tumor-bearing BALB/c mice. Importantly, the nanoparticles showed negligible systemic toxicity due to their synergistic effect on cancer cell dysfunction and significant amplification of intracellular glutathione consumption. Our findings suggest that the developed carrier-free nanomedicines offer a highly promising platform for the co-delivery of genistein (GEN) copper(II) complexes and 5-FU, with easy fabrication and great potential for clinical translation in HCC synergistic therapy.

Cisplatin-Based Combination Therapy for Enhanced Cancer Treatment.

Cisplatin, a primary chemotherapeutic drug, is of great value in the realm of tumor treatment. However, its clinical efficacy is strictly hindered by issues, such as drug resistance, relapse, poor prognosis, and toxicity to normal tissue. Cisplatin-based combination therapy has garnered increasing attention in both preclinical and clinical cancer research for its ability to overcome resistance, reduce toxicity, and enhance anticancer effects. This review examines three primary co-administration strategies of cisplatin-based drug combinations and their respective advantages and disadvantages. Additionally, seven types of combination therapies involving cisplatin are discussed, focusing on their main therapeutic effects, mechanisms in preclinical research, and clinical applications. This review also discusses future prospects and challenges, aiming to offer guidance for the development of optimal cisplatin-based combination therapy regimens for improved cancer treatment.

Targeting ENPP1 for cancer immunotherapy: Killing two birds with one stone.

Cancer immunotherapy, particularly with immune checkpoint inhibitors, has revolutionized the paradigm of cancer treatment. Nevertheless, the efficacy of cancer immunotherapy remains limited in most clinical settings due to the lack of a preexisting antitumor T-cell response in tumors. Therefore, the clinical outcomes of cancer immunotherapy must be improved crucially. With increased awareness of the importance of the innate immune response in the recruitment of T cells, as well as the onset and maintenance of the T cell response, great interest has been shown in activating the cGAS-STING signaling pathway to awaken the innate immune response, thereby orchestrating both innate and adaptive immune responses to induce tumor clearance. However, tumor cells have evolved to overexpress ectonucleotide pyrophosphate phosphodiesterase 1 (ENPP1), which degrades the immunotransmitter 2',3'-cGAMP and promotes the production of immune-suppressing adenosine, resulting in inhibition of the anticancer immune response in the tumor microenvironment. Clinically, ENPP1 overexpression is closely associated with poor prognosis in patients with cancer. Conversely, depleting or inhibiting ENPP1 has been verified to elevate extracellular 2',3'-cGAMP levels and inhibit the generation of adenosine, thereby reinvigorating the anticancer immune response for tumor elimination. A variety of ENPP1 inhibitors have recently been developed and have demonstrated significant promise for cancer immunotherapy. In this review, we provide an overview of ENPP1, dissect its immunosuppressive mechanisms, and discuss the development of ENPP1 inhibitors with the potential to further improve the efficacy of cancer immunotherapy.

Neuropharmacological insight into preventive intervention in posttraumatic epilepsy based on regulating glutamate homeostasis.

BACKGROUND: Posttraumatic epilepsy (PTE) is one of the most critical complications of traumatic brain injury (TBI), significantly increasing TBI patients' neuropsychiatric symptoms and mortality. The abnormal accumulation of glutamate caused by TBI and its secondary excitotoxicity are essential reasons for neural network reorganization and functional neural plasticity changes, contributing to the occurrence and development of PTE. Restoring glutamate balance in the early stage of TBI is expected to play a neuroprotective role and reduce the risk of PTE. AIMS: To provide a neuropharmacological insight for drug development to prevent PTE based on regulating glutamate homeostasis. METHODS: We discussed how TBI affects glutamate homeostasis and its relationship with PTE. Furthermore, we also summarized the research progress of molecular pathways for regulating glutamate homeostasis after TBI and pharmacological studies aim to prevent PTE by restoring glutamate balance. RESULTS: TBI can lead to the accumulation of glutamate in the brain, which increases the risk of PTE. Targeting the molecular pathways affecting glutamate homeostasis helps restore normal glutamate levels and is neuroprotective. DISCUSSION: Taking glutamate homeostasis regulation as a means for new drug development can avoid the side effects caused by direct inhibition of glutamate receptors, expecting to alleviate the diseases related to abnormal glutamate levels in the brain, such as PTE, Parkinson's disease, depression, and cognitive impairment. CONCLUSION: It is a promising strategy to regulate glutamate homeostasis through pharmacological methods after TBI, thereby decreasing nerve injury and preventing PTE.

Dual gatekeepers-modified mesoporous organic silica nanoparticles for synergistic photothermal-chemotherapy of breast cancer.

HYPOTHESIS: Construction of dual gatekeepers-functionalized mesoporous organic silica nanoparticles (MONs) with both physical and chemical mechanisms for modulated drug delivery properties provides one solution to the extracellular stability vs. intracellular high therapeutic efficiency of MONs that hold great potential for clinical translations. EXPERIMENTS: We reported herein facile construction of diselenium-bridged MONs decorated with dual gatekeepers, i.e., azobenzene (Azo)/polydopamine (PDA) for both physical and chemical modulated drug delivery properties. Specifically, Azo can act as a physical barrier to block DOX in the mesoporous structure of MONs for extracellular safe encapsulation. The PDA outer corona serves not only as a chemical barrier with acidic pH-modulated permeability for double insurance of minimized DOX leakage in the extracellular blood circulation but also for inducing a PTT effect for synergistic PTT and chemotherapy of breast cancer. FINDINGS: An optimized formulation, DOX@(MONs-Azo3)@PDA resulted in approximately 1.5 and 2.4 fold lower IC50 values than DOX@(MONs-Azo3) and (MONs-Azo3)@PDA controls in MCF-7 cells, respectively, and further mediated complete tumor eradication in 4T1 tumor-bearing BALB/c mice with insignificant systematic toxicity due to the synergistic PTT and chemotherapy with enhanced therapeutic efficiency.

Recent Advances and Next Breakthrough in Immunotherapy for Cancer Treatment.

With the huge therapeutic potential, cancer immunotherapy is expected to become the mainstream of cancer treatment. In the current field of cancer immunotherapy, there are mainly five types. Immune checkpoint blockade therapy is one of the most promising directions. Adoptive cell therapy is an important component of cancer immunotherapy. The therapy with the cancer vaccine is promising cancer immunotherapy capable of cancer prevention. Cytokine therapy is one of the pillars of cancer immunotherapy. Oncolytic immunotherapy is a promising novel component of cancer immunotherapy, which with significantly lower incidence of serious adverse reactions. The recent positive results of many clinical trials with cancer immunotherapy may herald good clinical prospects. But there are still many challenges in the broad implementation of immunotherapy. Such as the immunotherapy cannot act on all tumors, and it has serious adverse effects including but not limited to nonspecific and autoimmunity inflammation. Here, we center on recent progress made within the last 5 years in cancer immunotherapy. And we discuss the theoretical background, as well as the opportunities and challenges of cancer immunotherapy.

T-cell immunoglobulin and ITIM domain in cancer immunotherapy: A focus on tumor-infiltrating regulatory T cells.

T-cell immunoglobulin and ITIM domain (TIGIT) is a novel type of immune checkpoint. Importantly, immune checkpoint molecules promote cancer progression by various antitumor suppressive mechanisms. TIGIT is an inhibitory receptor expressed on T cells, natural killer cells, and regulatory T cells that was recently attracted attention as a major emerging target for cancer immunotherapy. Regulatory T cells (Tregs) play crucial roles in immune homeostasis. Specifically, tumor-infiltrating Tregs promote cancer progression by restricting antitumor immunity and supporting tumor immune escape. In this review, we summarized the current understanding on TIGIT and tumor-infiltrating Tregs. Here, we reviewed the latest advances in the understanding of mechanisms causing tumor-infiltrating Tregs abundance to optimize Tregs targeted therapy. Collectively, anti-TIGIT targeting Tregs hold great promise for potent cancer target therapy.

Interaction of aging and Immunosenescence: New therapeutic targets of aging.

Aging is a natural physiological process, but aging can increase the prevalence and mortality of chronic diseases in the elderly. It involves multiple organs and systems, and an essential aspect of aging is immunosenescence. With the increase of age, the immune system has undergone a series of changes and disorders. These changes have led to a decline in the resistance of the elderly to infection, reduced immunity to vaccines, increased incidence of cancer and autoimmune diseases, and an increased structural prevalence of low-grade inflammation. Moreover, affecting the aging process to a certain extent. This review introduces the changes in the immune system during aging and discusses the consequences and effects of these changes. And its effect on the aging process and the methods and ways of anti-aging were discussed.

Tumor microenvironment based stimuli-responsive CRISPR/Cas delivery systems: A viable platform for interventional approaches.

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) systems have emerged as robust tools in cancer gene therapy due to their simplicity and versatility. Nevertheless, the genome editing efficiency in tumor sites and the clinical applications of CRISPR/Cas have been compromised by non-specific delivery and genotoxicity. Recently, intelligent delivery systems incorporating sensitive materials in response to endogenous stimuli of the tumor microenvironment (TME) have represented viable platforms for tumor-specific genome editing and reduced side effects of CRISPR/Cas. Spurred by this promising direction, this review first introduces the CRISPR/Cas systems widely employed in cancer therapeutic explorations. Various types of CRISPR/Cas delivery systems sensitive to the stimuli in TME and typical dual-/multiple-responsive CRISPR/Cas carriers are further discussed, emphasizing the correlations between sensitive components and spatiotemporal delivery mechanisms. The genome editing efficiencies of CRISPR/Cas-loaded stimuli-responsive carriers are also summarized both in vitro and in vivo. Collectively, stimuli-responsive CRISPR/Cas delivery systems hold great promise for potent cancer gene therapy.

Targeting STING for cancer immunotherapy: From mechanisms to translation.

Cancer immunotherapy with immune checkpoint inhibitors has achieved unprecedented success in cancer treatment; However, only a subset of patients achieved clinical benefit from this treatment, underscoring the urgent need to identify new strategies to enhance the clinical efficacy of immune checkpoint inhibitors. Given the essential role of innate immunity in cancer immune surveillance, tremendous effort has been focused on the innate immune pathways that can be pharmacologically modulated to improve the clinical outcome of checkpoint inhibitors. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway plays essential roles in host defense against cancers. Activation of the cGAS-STING signaling pathway induces the expression of type I interferons and proinflammatory cytokines, culminating in promotion of a robust adaptive antitumor immunity. As part of this innate immune signaling pathway, STING is ubiquitously expressed in immune and nonimmune cells. STING activation has been demonstrated to propagate the cancer immunity cycle, remodel the tumor microenvironment, and ultimately eliminate tumor cells. The immunomodulatory roles of STING enable it to be an appealing target for cancer immunotherapy. As such, STING agonists that are capable of triggering antitumor immune responses have been developed in recent years, and several of them have advanced into clinical trials. In this review, we first give an overview on the STING signaling pathway, then dissect the roles of STING activation in different steps of the cancer immunity cycle and finally discuss the development of STING agonists as well as challenges with STING activation, with the potential to make cancer immunotherapy with STING agonists more effective.

Lactic acid, a driver of tumor-stroma interactions.

Warburg effect is one of the hallmarks of tumor favoring the suppression of normal oxidative phosphorylation (OxPhos) and the adaptation to hypoxia. In addition to providing continuous energy to meet the demands of tumors, acceleratedWarburg effect also producesa large amount of lactic acid. Lactic acid shuttles between different cell populations within the tumor microenvironment (TME) and confers tumor cells to interact with surrounding cells, which has emerged as a new phenomenon in the field of tumor biology and tumorigenesis. Lactic acid not only fulfills the energetic demands of stromal cells, but becomes a major regulator of their activity by serving as a signaling molecule. Activated stromal cells in turn support tumor development. In this review, we discuss the role of lactic acid in transformation and oncogenic function of stromal cells including fibroblasts, macrophages, adipocytes and vascular endothelial cells, and suggest the relevance of lactic acid in therapy response and essential questions in this field.

Targeting PRAS40: a novel therapeutic strategy for human diseases.

Proline-rich Akt substrate of 40 kD (PRAS40) is not only the substrate of protein kinase B (PKB/Akt), but also the binding protein of 14-3-3 protein. PRAS40 is expressed in a variety of tissues in vivo and has multiple phosphorylation sites, which its activity is closely related to phosphorylation. Studies have shown that PRAS40 is involved in regulating cell growth, cell apoptosis, oxidative stress, autophagy and angiogenesis, as well as various of signalling pathways such as mammalian target of mammalian target rapamycin (mTOR), protein kinase B (PKB/Akt), nuclear factor kappa-B(NF-κB), proto-oncogene serine/threonine-protein kinase PIM-1(PIM1) and pyruvate kinase M2 (PKM2). The interactive roles between PRAS40 and these signal proteins were analysed by bioinformatics in this paper. Moreover, it is of great necessity for analyse the important roles of PRAS40 in some human diseases including cardiovascular disease, ischaemia-reperfusion injury, neurodegenerative disease, cancer, diabetes and other metabolic diseases. Finally, the effects of miRNA on the regulation of PRAS40 function and the occurrence and development of PRAS40-related diseases are also discussed. Overall, PRAS40 is expected to be a drug target and provide a new treatment strategy for human diseases.

Mechanisms of immune escape in the cancer immune cycle.

Cancer is a critical issue globally with high incidence and mortality, imposing great burden on the society. Although great progress has been made in immunotherapy based on immune checkpoint, only a subset of patients responds to this treatment, suggesting that cancer immune evasion is still a major barrier in current immunotherapy. There are a series of factors contributing to immune evasion despite in an immunocompetent environment. Given that these factors are involved in different steps of the cancer immune cycle. In this review, we discuss the mechanisms of immune escape in each step of the cancer immune cycle and then present therapeutic strategies for overcoming immune escape, with the potential to better understand the determinants of immune escape and make anti-tumor immunity more effective.

Intelligent polymeric micelles for multidrug co-delivery and cancer therapy.

Polymeric micelles (PMs) play a vital role in multidrug co-delivery and cancer treatment. However, the development of intelligent PMs further allows PMs to accurately -target tumour, selectively release cargo multidrug and increase uptake. Therefore, targets, controlled release and uptake of intelligent PMs should be paid more attention to improvement synergistic therapeutic outcomes and minimize side effects. In this review, tumour targeting of co-delivery intelligent PMs and its intracellular trafficking mechanisms were overviewed. And this review provides a comprehensive summarization of several intelligent co-delivery PMs. Such a system could control the multidrug to be released simultaneously or sequentially by special properties of tumour microenvironment (TME) (including acidic PH, redox, overexpressed enzyme, excessive temperature) and external environment trigger. Additionally, limitations, clinical translation and future perspectives of intelligent co-delivery PMs were also being discussed in this article.