Recombinant measles virus vaccine rMV-Hu191 exerts an oncolytic effect on esophageal squamous cell carcinoma via caspase-3/GSDME-mediated pyroptosis

Insights into the different mechanisms of Autophagy and Apoptosis mediated by Morbilliviruses

Viruses are obligate intracellular parasites that have co-evolved with the host. During the course of evolution, viruses have acquired abilities to abrogate the host's immune responses by modulating the host proteins which play a pivotal role in various biological processes. One such process is the programmed cell death in virus-infected cells, which can occur via autophagy or apoptosis. Morbilliviruses are known to modulate both autophagy and apoptosis. Upon infecting a cell, the morbilliviruses can utilize autophagosomes as their nest and delay the host defense apoptotic response, and/or can promote apoptosis to escalate the virus dissemination. Moreover, there is an active interplay between these two pathways which eventually decides the fate of a virus-infected cell. Recent advances in our understanding of these processes provide a potential rationale to further explore morbilliviruses for therapeutic purposes.

Buyang Huanwu Decoction prevents hemorrhagic transformation after delayed t-PA infusion via inhibiting NLRP3 inflammasome/pyroptosis associated with microglial PGC-1α

ETHNOPHARMACOLOGICAL RELEVANCE

Delayed tissue-type plasminogen activator (t-PA) thrombolysis, which has a restrictive therapeutic time window within 4.5 h following ischemic stroke (IS), increases the risk of hemorrhagic transformation (HT) and subsequent neurotoxicity. Studies have shown that the NLRP3 inflammasome activation reversely regulated by the PGC-1α leads to microglial polarization and pyroptosis to cause damage to nerve cells and the blood-brain barrier. The effect of Buyang Huanwu Decoction (BHD), a traditional Chinese medicine prescription widely used in the recovery of IS, on HT injury after delayed t-PA treatment had been found with clinical studies, while the underlying mechanisms are reminded to be further clarified.

AIM OF THE STUDY

This study sought to investigate the therapeutic effect and the underlying mechanisms of BHD in ischemic rat brains with delayed t-PA treatment.

MATERIALS AND METHODS

The components of BHD extracts were identified by High Performance Liquid Chromatography (HPLC) and the effective components in the rat brains from BHD were analyzed by liquid chromatography-mass spectrometry (LC-MS). In vivo experiment was carried out by 5 h of middle cerebral artery occlusion (MCAO) following by t-PA infusion for 0.5 h plus reperfusion 19 h, while the in vitro BV2 cells were stimulated by lipopolysaccharide (LPS)-adenosine triphosphate (ATP) to activate microglia pyroptosis, of which the MCC950 (NLRP3 inhibitor) and NSA (GSDMD inhibitor) were adopted as reverse validation. PGC-1α siRNA was utilized to study the mechanisms of BHD against microglial polarization and pyroptosis in BV2 cells.

RESULTS

HPLC analysis demonstrated the fingerprint of BHD with six reference standards (Hydroxysafflor yellow A, Calycosin-7-glucoside, Paeoniflorin, Formononetin, Ferulic acid and Amygdalin), the last two of which can be found in rat brains by LC-MS analysis. In the following experiments, we found the major discoveries as follow: (1) BHD improved the neurological outcomes, the structural integrity of the blood-brain barrier and the neuronal structure in HT rats with MCAO following by delayed t-PA infusion; (2) the presence of t-PA promoted the suppression of PGC-1α and the activation of microglial NLRP3 inflammasome and pyroptosis in the HT rats; (3) BHD promoted the transformation of microglia from M1 to M2 type for inhibiting inflammatory response; (4) BHD restrained NLRP3 inflammasome/pyroptosis activation in microglia, prevented the translocations of NF-κB into the nucleus, as well as enhanced microglia-specific PGC-1α in ischemic rats following t-PA delayed thrombolysis; (5) BHD suppressed NLRP3 inflammasome assembly and increased PGC-1α expression in the LPS-ATP-induced BV2 cells; (6) PGC-1α silencing withdrew the protective role of BHD against NLRP3 inflammasome/pyroptosis.

CONCLUSION

Mechanistically, BHD existed the protective effect against HT injury after delayed t-PA treatment through up-regulating microglial PGC-1α to inhibit NLRP3 inflammasome and pyroptosis, and serves as a potential adjuvant therapy for HT injury.

Gasdermin E mediates pyroptosis in the progression of hepatocellular carcinoma: a double-edged sword

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer worldwide. It usually develops due to viral hepatitis or liver cirrhosis. The molecular mechanisms involved in HCC pathogenesis are complex and incompletely understood. Gasdermin E (GSDME) is a tumor suppressor gene and is inhibited in most cancers. Recent studies have reported that, unlike those in most tumors, GSDME is highly expressed in liver cancer, and GSDME expression in HCC is negatively associated with prognosis, suggesting that GSDME may promote HCC. However, antitumor drugs can induce pyroptosis through GSDME, killing HCC cells. Therefore, GSDME may both inhibit and promote HCC development. Because functional studies of GSDME in HCC are limited, the precise molecular mechanisms of GSDME in liver cancer remain unclear. In this article, we have reviewed the role, related mechanisms, and clinical importance of GSDME at the onset and development of HCC to provide a theoretical foundation to improve the clinical diagnosis and treatment of liver cancer.

A novel approach for breast cancer treatment: the multifaceted antitumor effects of rMeV-Hu191

BACKGROUND

The therapeutic potential of oncolytic measles virotherapy has been demonstrated across various malignancies. However, the effectiveness against human breast cancer (BC) and the underlying mechanisms of the recombinant measles virus vaccine strain Hu191 (rMeV-Hu191) remain unclear.

METHODS

We utilized a range of methods, including cell viability assay, Western blot, flow cytometry, immunofluorescence, SA-β-gal staining, reverse transcription quantitative real-time PCR, transcriptome sequencing, BC xenograft mouse models, and immunohistochemistry to evaluate the antitumor efficacy of rMeV-Hu191 against BC and elucidate the underlying mechanism. Additionally, we employed transcriptomics and gene set enrichment analysis to analyze the lipid metabolism status of BC cells following rMeV-Hu191 infection.

RESULTS

Our study revealed the multifaceted antitumor effects of rMeV-Hu191 against BC. rMeV-Hu191 induced apoptosis, inhibited proliferation, and promoted senescence in BC cells. Furthermore, rMeV-Hu191 was associated with changes in oxidative stress and lipid homeostasis in infected BC cells. In vivo, studies using a BC xenograft mouse model confirmed a significant reduction in tumor growth following local injection of rMeV-Hu191.

CONCLUSIONS

The findings highlight the potential of rMeV-Hu191 as a promising treatment for BC and provide valuable insights into the mechanisms underlying its oncolytic effect.

Harnessing Pyroptosis for Cancer Immunotherapy

Cancer immunotherapy is a novel pillar of cancer treatment that harnesses the immune system to fight tumors and generally results in robust antitumor immunity. Although immunotherapy has achieved remarkable clinical success for some patients, many patients do not respond, underscoring the need to develop new strategies to promote antitumor immunity. Pyroptosis is an immunostimulatory type of regulated cell death that activates the innate immune system. A hallmark of pyroptosis is the release of intracellular contents such as cytokines, alarmins, and chemokines that can stimulate adaptive immune activation. Recent studies suggest that pyroptosis promotes antitumor immunity. Here, we review the mechanisms by which pyroptosis can be induced and highlight new strategies to induce pyroptosis in cancer cells for antitumor defense. We discuss how pyroptosis modulates the tumor microenvironment to stimulate adaptive immunity and promote antitumor immunity. We also suggest research areas to focus on for continued development of pyroptosis as an anticancer treatment. Pyroptosis-based anticancer therapies offer a promising new avenue for treating immunologically 'cold' tumors.

The multifaceted roles of GSDME-mediated pyroptosis in cancer: therapeutic strategies and persisting obstacles

Pyroptosis is a novel regulated cell death (RCD) mode associated with inflammation and innate immunity. Gasdermin E (GSDME), a crucial component of the gasdermin (GSDM) family proteins, has the ability to convert caspase-3-mediated apoptosis to pyroptosis of cancer cells and activate anti-tumor immunity. Accumulating evidence indicates that GSDME methylation holds tremendous potential as a biomarker for early detection, diagnosis, prognosis, and treatment of tumors. In fact, GSDME-mediated pyroptosis performs a dual role in anti-tumor therapy. On the one side, pyroptotic cell death in tumors caused by GSDME contributes to inflammatory cytokines release, which transform the tumor immune microenvironment (TIME) from a 'cold' to a 'hot' state and significantly improve anti-tumor immunotherapy. However, due to GSDME is expressed in nearly all body tissues and immune cells, it can exacerbate chemotherapy toxicity and partially block immune response. How to achieve a balance between the two sides is a crucial research topic. Meanwhile, the potential functions of GSDME-mediated pyroptosis in anti-programmed cell death protein 1 (PD-1) therapy, antibody-drug conjugates (ADCs) therapy, and chimeric antigen receptor T cells (CAR-T cells) therapy have not yet been fully understood, and how to improve clinical outcomes persists obscure. In this review, we systematically summarize the latest research regarding the molecular mechanisms of pyroptosis and discuss the role of GSDME-mediated pyroptosis in anti-tumor immunity and its potential applications in cancer treatment.