Nanomedicines hold great potential in anticancer therapy by modulating the biodistribution of nanomaterials and initiating targeted oxidative stress damage, but they are also limited by the inherent self-protection mechanism and the evolutionary treatment resistance of cancer cells. New emerging explorations of regulated cell death (RCD), including processes related to autophagy, ferroptosis, pyroptosis, and necroptosis, substantially contribute to the augmented therapeutic efficiency of tumors by increasing the sensitivity of cancer cells to apoptosis. Herein, paradigmatic studies of RCD-mediated synergistic tumor nanotherapeutics are introduced, such as regulating autophagy-enhanced photodynamic therapy (PDT), targeting ferroptosis-sensitized sonodynamic therapy (SDT), inducing necroptosis-augmented photothermal therapy (PTT), and initiating pyroptosis-collaborative chemodynamic therapy (CDT), and the coordination mechanisms are discussed in detail. Multiangle analyses addressing the present challenges and upcoming prospects of RCD-based nanomedicines have also been highlighted and prospected for their further strengthening and the broadening of their application scope. It is believed that up-and-coming coadjutant therapeutic methodologies based on RCDs will considerably impact precision nanomedicine for cancer.

Targeting regulated cell death in tumor nanomedicines

The multifaceted roles of gasdermins in cancer biology and oncologic therapies.

Pyroptosis is commonly induced by the gasdermin (GSDM) family and is accompanied by the release of inflammatory cytokines such as IL-1β and IL-18. Recently, increasing evidence suggests that pyroptosis plays a role in respiratory diseases. This review aimed to summarize the roles and mechanisms of pyroptosis in inflammation-related respiratory diseases. There are several pathways involved in pyroptosis, such as the canonical inflammasome-induced pathway, non-canonical inflammasome-induced pathway, caspase-1/3/6/7/GSDMB pathway, caspase-8/GSDMC pathway, caspase-8/GSDMD pathway, and caspase-3/GSEME pathway. Pyroptosis may be involved in asthma, chronic obstructive pulmonary disease (COPD), lung cancer, acute lung injury (ALI), silicosis, pulmonary hypertension (PH), and tuberculosis (TB), in which the NLRP3 inflammasome-induced pathway is mostly highlighted. Pyroptosis contributes to the deterioration of asthma, COPD, ALI, silicosis, and PH. In addition, pyroptosis has dual effects on lung cancer and TB. Additionally, whether pyroptosis participates in cystic fibrosis (CF) and sarcoidosis or not is largely unknown, though the activation of NLRP3 inflammasome is found in CF and sarcoidosis. In conclusion, pyroptosis may play a role in inflammation-related respiratory diseases, providing new therapeutic targets. 

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Pyroptosis in inflammation-related respiratory disease

Therapy resistance, which leads to the development of loco-regional relapses and distant metastases after treatment, constitutes one of the major problems that head and neck squamous cell carcinoma (HNSCC) patients currently face. Thus, novel therapeutic strategies are urgently needed. Targeted drug delivery to the chemokine receptor 4 (CXCR4) represents a promising approach for HNSCC management. In this context, we have developed the self-assembling protein nanotoxins T22-PE24-H6 and T22-DITOX-H6, which incorporate the de-immunized catalytic domain of Pseudomonas aeruginosa (PE24) exotoxin A and the diphtheria exotoxin (DITOX) domain, respectively. Both nanotoxins contain the T22 peptide ligand to specifically target CXCR4-overexpressing HNSCC cells. In this study, we evaluate the potential use of T22-PE24-H6 and T22-DITOX-H6 nanotoxins for the treatment of HNSCC.T22-PE24-H6 and T22-DITOX-H6 CXCR4-dependent cytotoxic effect was evaluated in vitro in two different HNSCC cell lines. Both nanotoxins cell death mechanisms were assessed in HNSCC cell lines by phase-contrast microscopy, AnnexinV/ propidium iodide (PI) staining, lactate dehydrogenase (LDH) release assays, and western blotting. Nanotoxins antitumor effect in vivo was studied in a CXCR4+ HNSCC subcutaneous mouse model. Immunohistochemistry, histopathology, and toxicity analyses were used to evaluate both nanotoxins antitumor effect and possible treatment toxicity. GSMDE and CXCR4 expression in HNSCC patient tumor samples was also assessed by immunohistochemical staining.First, we found that both nanotoxins exhibit a potent CXCR4-dependent cytotoxic effect in vitro. Importantly, nanotoxin treatment triggered caspase-3/Gasdermin E (GSDME)-mediated pyroptosis. The activation of this alternative cell death pathway that differs from traditional apoptosis, becomes a promising strategy to bypass therapy resistance. In addition, T22-PE24-H6 and T22-DITOX-H6 displayed a potent antitumor effect in the absence of systemic toxicity in a CXCR4+ subcutaneous HNSCC mouse model. Lastly, GSDME was found to be overexpressed in tumor tissue from HNSCC patients, highlighting the relevance of this strategy.Altogether, our results show that T22-PE24-H6 and T22-DITOX-H6 represent a promising therapy for HNSCC patients. Remarkably, this is the first study showing that both nanotoxins are capable of activating caspase-3/GSDME-dependent pyroptosis, opening a novel avenue for HNSCC treatment. 

/pdf/cxcr4-targeted-nanotoxins-induce-gsdme-dependent-pyroptosis-3ocmggv8.pdf

CXCR4-targeted nanotoxins induce GSDME-dependent pyroptosis in head and neck squamous cell carcinoma

/pdf/cxcr4-targeted-nanotoxins-induce-gsdme-dependent-pyroptosis-3j7ilwot.pdf

The side effects of platinum-based chemotherapy are important factors limiting the survival of oral squamous cell carcinoma (OSCC) patients. Current research suggests that pyroptosis is involved in this process. However, how this mechanism can be used to reduce side effects has not yet been elucidated. In this study, we reported that GSDME was expressed at higher levels in normal tissues than in cancerous tissues in OSCC patients and was the main cause of platinum-based side effects. In an OSCC xenograft model, the inflammatory status and GSDME expression were increased after cisplatin chemotherapy. Cellular experiments showed that higher expression of GSDME was associated with less chemoresistance to cisplatin. A subsequent study demonstrated that cisplatin treatment promotes the maturation of caspase-3, triggers GSDME-mediated pyroptosis and induces cell death. When the amino acid sequence of GSDME cleaved by caspase-3 was mutated, cellular death and pyroptosis induced by cisplatin were significantly inhibited. Moreover, application of vitamin D during cisplatin-based chemotherapy could successfully inhibit GSDME cleavage and pyroptotic cell death in vitro and in vivo. Taken together, our study revealed that vitamin D can inhibit caspase-3-mediated GSDME cleavage and thus reduce normal tissue pyroptosis, relieving chemotherapeutic side effects. Inhibition of systemic GSDME during chemotherapy is currently unachievable. Vitamin D supplementation during chemotherapy in OSCC patients might be able to reduce the process described above and benefit patients. However, additional follow-up clinical studies are needed.

Inhibition of caspase-3-mediated GSDME-derived pyroptosis aids in noncancerous tissue protection of squamous cell carcinoma patients during cisplatin-based chemotherapy.

A convenient method for distinguishing human and mouse cells in situ.

The mouse xenograft model is one of the most widely used animal model for biomedicine research. It is vital to distinguish the cells from different species, especially for the spatial distribution information. However, the available strategies of species-specific detection are either inapplicable in situ or of low specificity. Here, we reported a method based on DAPI staining, which offers an effective, convenient way that accurately identifies human and mouse nuclei at single-cell level in situ. This method was proven to be effective in cell co-culture and tumor xenograft tissue section. Microscopic imaging results shows obvious DAPI plaques-like structures in mouse nuclei, but absent in human nuclei. Moreover, we found these structures are co-localized with mouse major satellite DNA, which is located pericentromere in mouse, but absent in human. Our study provides a high-performance method that can be widely used for distinguish human and mouse cell in situ.

/pdf/a-new-method-for-distinguishing-human-and-mouse-cells-in-4olrgz3lzh.pdf

Yongqiang Wang

Papers

Inhibition of caspase-3-mediated GSDME-derived pyroptosis aids in noncancerous tissue protection of squamous cell carcinoma patients during cisplatin-based chemotherapy.

A convenient method for distinguishing human and mouse cells in situ.

A new method for distinguishing human and mouse cells in situ