Targeting macrophage priming by polyphyllin VII triggers anti-tumor immunity via STING-governed cytotoxic T-cell infiltration in lung cancer

Multimodal integrated strategy for the discovery and identification of antiplatelet aggregation Q-markers in Paris polyphylla var. yunnanensis

To enhance the quality evaluation and control of traditional Chinese medicine (TCM) and ensure the safety and efficacy of clinical medication, it is imperative to establish a comprehensive quality assessment method aligned with TCM efficacy. This study uses a representative Chinese medicine with multi-origin and multi-efficacy, Paris polyphylla var. yunnanensis (PY), as an illustrative example. Surprisingly, despite the high fingerprint similarity among the 12 batches of PY samples collected from various regions in Yunnan, a notable variation in the composition and content of components was observed. The chromatographic analysis identified seven common peaks, namely, polyphyllin I, polyphyllin II, polyphyllin V, polyphyllin VI, polyphyllin VII, polyphyllin H, and polyphyllin D. In the bioactivity evaluation, an in vitro antiplatelet aggregation model induced by adenosine diphosphate was established, showcasing excellent stability. The maximum antiplatelet aggregation inhibition rate for all PY samples consistently remained stable at 73.1%-99.1%. However, the 50% inhibitory concentration (IC50 ) values exhibited a range from 1.615 to 18.200 mg/mL. This approach not only meets high-throughput screening requirements but also demonstrates remarkable discrimination. The results of chemical and bioactivity evaluations were analyzed using hierarchical cluster analysis and canonical correlation analysis. Polyphyllin I, polyphyllin II, polyphyllin VII, polyphyllin H, and polyphyllin D were identified as the Q-markers for antiplatelet aggregation in PY samples. Validation of the bioactivity for these monomer components aligned with the previously mentioned findings. Notably, this study established a spectrum-effect model for PY samples, enhancing the scientific robustness of the quality evaluation method. Furthermore, these findings offer valuable research insights for improving the quality assessment of other TCMs.

Radiation Synergizes with IL2/IL15 Stimulation to Enhance Innate Immune Activation and Antitumor Immunity

Ionizing radiation is known to possess immune modulatory properties. However, how radiotherapy (RT) may complement with different types of immunotherapies to boost antitumor responses is unclear. In mice implanted with EO771 syngeneic tumors, NL-201 a stable, highly potent CD25-independent agonist to IL2 and IL15 receptors with enhanced affinity for IL2Rβγ was given with or without RT. Flow analysis and Western blot analysis was performed to determine the mechanisms involved. STING (-/-) and CD11c+ knockout mice were implanted with EO771 tumors to confirm the essential signaling and cell types required to mediate the effects seen. Combination of RT and NL-201 to enhance systemic immunotherapy with an anti-PD-1 checkpoint inhibitor was utilized to determine tumor growth inhibition and survival, along characterization of tumor microenvironment as compared with all other treatment groups. Here, we showed that RT, synergizing with NL-201 produced enhanced antitumor immune responses in murine breast cancer models. When given together, RT and NL-201 enhanced activation of the cytosolic DNA sensor cyclic GMP-AMP synthase-stimulator of IFN genes (cGAS-STING) pathway, resulting in increased type I IFN production in dendritic cells (DC), and consequently greater tumor infiltration and more efficient priming of antigen-specific T cells. The immune stimulatory mechanisms triggered by NL-201 and RT resulted in superior tumor growth inhibition and survival benefit in both localized and metastatic cancers. Our results support further preclinical and clinical investigation of this novel synergism regimen in locally advanced and metastatic settings.

Polyphyllins in cancer therapy: A systematic review and meta-analysis of animal studies

BACKGROUND

Polyphyllins are secondary metabolites that inhibit the growth of various tumours; however, clinical trials on their use are lacking.

HYPOTHESIS/PURPOSE

In this study, we aimed to evaluate the antitumour efficacy of polyphyllins in animal models.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Electronic bibliographic databases including PubMed, Web of Science, China Science and Technology Journal Database, Wanfang Data, and China National Knowledge Infrastructure were searched for relevant articles. The Systematic Review Centre for Laboratory Animal Experimentation's Risk of Bias tool was used to assess methodological quality. RevMan V.5.4 (Cochrane) and Stata MP 17 software were used to perform a meta-analysis.

RESULTS

Thirty articles were analysed including 33 independent experiments and 452 animals in this paper. Overall, tumour volume (standardised mean difference [SMD]: -3.35; 95 % confidence interval [CI]: -4.27 to -2.43; p < 0.00001) and tumour weight (SMD: -3.79; 95% CI: -4.75 to -2.82; p < 0.00001) were reduced by polyphyllins, which showed a good cancer therapeutic effect; mouse weight (SMD: -0.22; 95% CI: -0.61 to -0.18; p = 0.28) was insignificantly different, which indicated that polyphyllins did not affect the growth of the mice within the test range. Moreover, the molecular mechanisms of the antitumour activity of polyphyllins were explained, including the P53, NF-kB, AMPK, and ERK signalling pathways.

CONCLUSION

Polyphyllins inhibit the growth of cancers within the experimental dose. However, due to heterogeneity of the results of the included studies, more studies are needed to support this conclusion.

Polyphyllin VII alleviates pulmonary hypertension by inducing miR-205-5p to target the β-catenin pathway

OBJECTIVE

This study aims to investigate the impact of Polyphyllin VII (PP7) on pulmonary hypertension (PH) and elucidate the underlying mechanism involving microRNA (miR)-205-5p/β-catenin.

METHODS

The PH rat model was induced through hypoxia exposure. The effects of intraperitoneal injection of PP7 on pulmonary artery tissue pathology, hemodynamics, miR-205-5p expression and β-catenin protein levels were assessed. In vitro, pulmonary arterial smooth muscle cells (PASMCs) were subjected to hypoxic conditions. Moreover, miR-205-5p and/or β-catenin were overexpressed through transfection. PASMCs were pre-cultured in 20 μM PP7, and subsequent measurements included proliferation, apoptosis and vascular remodeling protein expression.

RESULTS

PP7 ameliorated PH symptoms in rats, upregulated miR-205-5p expression and inhibited β-catenin protein expression. Furthermore, miR-205-5p upregulation inhibited β-catenin expression in PASMCs. The overexpression of β-catenin aggravated hypoxia-induced proliferation, inhibited apoptosis and further augmented VEGF and α-SMA protein expression. Additionally, miR-205-5p overexpression alleviated the hypoxia-induced PASMC proliferation and apoptosis by inhibiting β-catenin protein expression. Under hypoxic conditions, PP7 significantly elevated miR-205-5p while downregulating β-catenin protein expression. Furthermore, inhibiting miR-205-5p counteracted the inhibitory effect of PP7 on β-catenin, consequently blocking the regulatory role of PP7 in PASMC proliferation and apoptosis.

CONCLUSION

PP7 likely modulates β-catenin protein levels by promoting miR-205-5p expression, thereby alleviating PH, vascular remodeling and airway smooth muscle remodeling.

Tespa1 deficiency reduces the antitumour immune response by decreasing CD8+T cell activity in a mouse Lewis lung cancer model

Thymocyte-expressed, positive selection-associated 1 (Tespa1) is a key molecule in T-cell development and has been linked to immune diseases. However, its role in antitumour CD8+T cell immunity remains unclear. Here, we demonstrated that Tespa1 plays an important role in antitumour CD8+T cell immunity. First, compared with wild-type (WT) mice, Lewis lung cancer cells grew faster in Tespa1 knockout (Tespa1-/-) mice, with reduced apoptosis, and decreased CD8+T cells in peripheral blood and tumor tissues. Second, the proportion of CD8+T and Th1 cells in the splenocytes of Tespa1-/- mice was lower than that in WT mice. Third, Tespa1-/- CD8+ tumor-infiltrating lymphocytes (TILs) showed weakened proliferation, invasion, cytotoxicity, and protein expression of IL-2 signalling pathway components compared to WT CD8+TILs. Furthermore, PD-1 expression in CD8+TILs was higher in Tespa1-/- than in WT mice. Lastly, CD8+TILs in WT mice improved the antitumour ability of Tespa1-/- mice. In conclusion, these findings suggest that Tespa1 plays a critical role in the tumor immune system by regulating CD8+T cells.

Steroid and triterpenoid saponins from the rhizomes of Paris polyphylla var. stenophylla

Five new saponins, including three steroid saponins, paristenoids A-C (1-3), and two triterpenoid saponins, paristenoids D-E (4-5), along with four known ones (6-9) were isolated from the rhizomes of Paris polyphylla var. stenophylla. The structures of the isolated compounds were identified mainly by detailed spectroscopic analysis, including extensive 1D and 2D NMR, MS, as well as chemical methods. Compound 3 is a new cyclocholestanol-type steroidal saponin with a rare 6/6/6/5/5 fused-rings cholestanol skeleton, and this skeleton has been first found from the genus Paris. The cytotoxicities of the isolated compounds against three human three glioma cell lines (U87MG, U251MG and SHG44) were evaluated, and compound 7 displayed certain inhibitory effect with IC50 values of 15.22 ± 1.73, 18.87 ± 1.81 and 17.64 ± 1.69 μmol·L-1, respectively.

Transforming Cold Tumors into Hot Ones with a Metal-Organic Framework-Based Biomimetic Nanosystem for Enhanced Immunotherapy

Immunotherapy has revolutionized the landscape in clinical tumor therapy, although the response rates in "cold" tumors are relatively low owing to the complex tumor microenvironment (TME). Cyclic guanosine monophosphate-adenosine monophosphate synthase/stimulator of interferon genes (cGAS/STING) pathway-inducing agents can reprogram the TME; however, their applications remain underutilized. Herein, we engineered a facile manganese-based metal-organic framework (Mn-MOF) encapsulating polyphyllin I (PPI) and coated it with red blood cell (RBC) membranes (RBC@Mn-MOF/PPI) that enhanced the cGAS/STING-mediated antitumor immunity. RBC@Mn-MOF/PPI was engineered by camouflaging it with a biomimetic RBC membrane for prolonged blood circulation and immune escape, which was also extended with TME-sensitive properties for triggering the release of PPI and Mn²⁺ to remodel the suppressive TME and augment antitumor immune responses. Furthermore, RBC@Mn-MOF/PPI helped transform cold tumors into "hot" ones by activating immune cells, as evidenced via dendritic cell maturation, cytotoxic T lymphocyte infiltration, and natural killer cell recruitment, thereby targeting primary and abscopal tumors and lung metastatic nodules. Therefore, our engineered nanosystem represents a novel strategy to transform immunologically "cold" tumors into "hot" ones by activating the cGAS/STING pathway, thereby addressing the major challenges associated with immunotherapy.

Cytotoxic steroidal glycosides from the rhizomes of Paris polyphylla var. yunnanensis

Paris polyphylla var. yunnanensis (Franch.) Hand.-Mazz. (Melanthiaceae), an important specie of the genus Paris, has long been in a traditional Chinese medicine (TCM) for a long time. This study aimed to isolate and identify the structures of bioactive saponins from the rhizomes of P. polyphylla var. yunnanensis and evaluate their cytotoxicity against BxPC-3, HepG2, U373 and SGC-7901 carcinoma cell lines. Seven previously undescribed and seven known saponins were identified, and Paris saponins VII (PSVII) showed significant cytotoxicity against the BxPC-3 cell line with IC₅₀ values of 3.59 μM. Furthermore, flow cytometry, transmission electron microscopy and western-bolt analysis revealed that PSVII inhibited the proliferation of BxPC-3 cells and might be involved in inducing apoptosis and pyroptosis by activating caspase-3, -7 and caspase-1, respectively.

The Microtubule Destabilizer Eribulin Synergizes with STING Agonists to Promote Antitumor Efficacy in Triple-Negative Breast Cancer Models

Eribulin is a microtubule destabilizer used in the treatment of triple-negative breast cancer (TNBC). Eribulin and other microtubule targeted drugs, such as the taxanes, have shared antimitotic effects, but differ in their mechanism of microtubule disruption, leading to diverse effects on cellular signaling and trafficking. Herein, we demonstrate that eribulin is unique from paclitaxel in its ability to enhance expression of the immunogenic cytokine interferon beta (IFNβ) in combination with STING agonists in both immune cells and TNBC models, including profound synergism with ADU-S100 and E7766, which are currently undergoing clinical trials. The mechanism by which eribulin enhances STING signaling is downstream of microtubule disruption and independent of the eribulin-dependent release of mitochondrial DNA. Eribulin did not override the requirement of ER exit for STING activation and did not inhibit subsequent STING degradation; however, eribulin significantly enhanced IRF3 phosphorylation and IFNβ production downstream of the RNA sensing pathway that converges on this transcription factor. Additionally, we found that eribulin enhanced the population of activated CD4⁺ T-cells in vivo when combined with either a STING agonist or tumor, demonstrating the ability to function as an immune adjuvant. We further interrogated the combination of eribulin with ADU-S100 in the MMTV-PyVT spontaneous murine mammary tumor model where we observed significant antitumor efficacy with combination treatment. Together, our findings demonstrate that microtubule targeted chemotherapeutics have distinct immunological effects and that eribulin's ability to enhance innate immune sensing pathways supports its use in combination with immunotherapies, such as STING agonists, for the more effective treatment of TNBC and other malignancies.

Cancer immunotherapy based on image-guided STING activation by nucleotide nanocomplex-decorated ultrasound microbubbles

The cytosolic innate immune sensor cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is crucial for priming adaptive antitumour immunity through antigen-presenting cells (APCs). Natural agonists, such as cyclic dinucleotides (CDNs), activate the cGAS-STING pathway, but their clinical translation is impeded by poor cytosolic entry and serum stability, low specificity and rapid tissue clearance. Here we developed an ultrasound (US)-guided cancer immunotherapy platform using nanocomplexes composed of 2'3'-cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) electrostatically bound to biocompatible branched cationic biopolymers that are conjugated onto APC-targeting microbubbles (MBs). The nanocomplex-conjugated MBs engaged with APCs and efficiently delivered cGAMP into the cytosol via sonoporation, resulting in activation of cGAS-STING and downstream proinflammatory pathways that efficiently prime antigen-specific T cells. This bridging of innate and adaptive immunity inhibited tumour growth in both localized and metastatic murine cancer models. Our findings demonstrate that targeted local activation of STING in APCs under spatiotemporal US stimulation results in systemic antitumour immunity and improves the therapeutic efficacy of checkpoint blockade, thus paving the way towards novel image-guided strategies for targeted immunotherapy of cancer.

Natural compounds: A new perspective on targeting polarization and infiltration of tumor-associated macrophages in lung cancer

With the development in tumor immunology, people are gradually understanding the complexity and diversity of the tumor microenvironment immune status and its important effect on tumors. Tumor-associated macrophages (TAMs), an important part of the tumor immune microenvironment, have a double effect on tumor growth and metastasis. Many studies have focused on lung cancer, especially non-small cell lung cancer and other "hot tumors" with typical inflammatory characteristics. The polarization and infiltration of TAMs is an important mechanism in the occurrence and development of malignant tumors, such as lung cancer, and in the tumor immune microenvironment. Therapeutic drugs designed for these reasons are key to targeting TAMs in the treatment of lung cancer. A large number of reports have suggested that natural compounds have a strong potential of affecting immunity by targeting the polarization and infiltration of TAMs to improve the immune microenvironment of lung cancer and exert a natural antitumor effect. This paper discusses the infiltration and polarization effects of natural compounds on lung cancer TAMs, provides a detailed classification and systematic review of natural compounds, and summarizes the bias of different kinds of natural compounds by affecting their antitumor mechanism of TAMs, with the aim of providing new perspectives and potential therapeutic drugs for targeted macrophages in the treatment of lung cancer.

The cGAS-STING Pathway: A Promising Immunotherapy Target

With the continuous development of immunotherapy, researchers have paid more attention to the specific immune regulatory mechanisms of various immune responses in different diseases. As a novel and vital innate immune signal pathway, the cGAS-STING signal pathway activated by nucleic acid substances, interplays with other immune responses, by which it participates in regulating cancer, autoimmune and inflammatory diseases, microbial and parasitic infectious diseases, and other diseases. With the exception of its role in innate immunity, the growing list of researches demonstrated expanding roles of the cGAS-STING signal pathway in bridging the innate immunity (macrophage polarization) with the adaptive immunity (T lymphocytes differentiation). Macrophages and T lymphocytes are the most representative cells of innate immunity and adaptive immunity, respectively. Their polarization or differentiation are involved in the pathogenesis and progression of various diseases. Here we mainly summarized recent advanced discoveries of how the cGAS-STING signal pathway regulated macrophages polarization and T lymphocytes differentiation in various diseases and vaccine applications, providing a promising direction for the development and clinical application of immunotherapeutic strategies for related diseases.

New Steroidal Saponins Isolated from the Rhizomes of Paris mairei

The genus Paris is an excellent source of steroidal saponins that exhibit various bioactivities. Paris mairei is a unique species and has been widely used as folk medicine in Southwest China for a long time. With the help of chemical methods and modern spectra analysis, five new steroidal saponins, pamaiosides A–E (1–5), along with five known steroidal saponins 6–10, were isolated from the rhizomes of Paris mairei. The cytotoxicity of all the new saponins was evaluated against human pancreatic adenocarcinoma PANC-1 and BxPC3 cell lines.

Chemical Constituents and Pharmacological Activities of Steroid Saponins Isolated from Rhizoma Paridis

Rhizoma Paridis, the rhizome of liliaceous plants Paris polyphylla, is one of the most commonly used herbal drugs in China. Phytochemical and pharmacological studies have shown that steroid saponins were the major effective ingredients of Rhizoma Paridis to exert antitumor, anti-inflammatory, hemostasis, and antifibrosis functions. In this review, we discussed the chemical structures of steroid saponins and their related biological activity and mechanisms in cellular and animal models, aiming to provide a reference for future comprehensive exploitation and development of saponins.

Bringing Macrophages to the Frontline against Cancer: Current Immunotherapies Targeting Macrophages

Macrophages are found in all tissues and display outstanding functional diversity. From embryo to birth and throughout adult life, they play critical roles in development, homeostasis, tissue repair, immunity, and, importantly, in the control of cancer growth. In this review, we will briefly detail the multi-functional, protumoral, and antitumoral roles of macrophages in the tumor microenvironment. Our objective is to focus on the ever-growing therapeutic opportunities, with promising preclinical and clinical results developed in recent years, to modulate the contribution of macrophages in oncologic diseases. While the majority of cancer immunotherapies target T cells, we believe that macrophages have a promising therapeutic potential as tumoricidal effectors and in mobilizing their surroundings towards antitumor immunity to efficiently limit cancer progression.

HBsAg Dampened STING Associated Activation of NK Cells in HBeAg-Negative CHB Patients

NK cells play crucial roles in defending against persistent HBV. However, NK cells present dysfunction in chronic hepatitis B virus (CHB) infection, and the associated mechanism is still not fully understood. Except for the regulatory receptors, NK cells could also be regulated by the surface and intracellular pattern recognition receptors (PRRs). In the present study, we found that the level of the adaptor of DNA sensor STING in NK cells was significantly decreased in HBeAg-negative CHB patients, and it was positively associated with the degranulation ability of NK cells. Compared to NK cells from healthy donors, NK cells from HBeAg-negative CHB patients displayed a lower responsiveness to cGAMP stimulation. Further investigation showed that HBsAg could inhibit the STING expression in NK cells and suppress the response of NK cells to cGAMP. Significantly, STAT3 was identified to be a transcription factor that directly regulated STING transcription by binding to the promoter. In addition, STAT3 positively regulated the STING associated IFN-α response of NK cells. These findings suggested that STING is an important adaptor in NK cell recognition and activation, while HBsAg disturbs NK cell function by the STAT3-STING axis, providing a new mechanism of NK disability in HBeAg-negative CHB infection.