NIR-responsive copper nanoliposome composites for cascaded ferrotherapy via ferroptosis actived ICD and IFN-γ released

Metallic biomaterials activate tumor ferroptosis by increasing oxidative stress, but their efficacy is severely limited in tumor microenvironment. Although interferon gamma (IFN-γ) can promote tumor ferroptosis sensitivity by inhibiting the antioxidant system and promoting lipid accumulation, this effect limited by the lack of IFN-γ accumulation in tumors. Herein, we report a near-infrared (NIR)-responsive HCuS nanocomposite (HCuS-PE@TSL-tlyp-1) that can stimulate immunogenic cell death (ICD)-mediated IFN-γ secretion through exogenous oxidative stress, thereby achieving cascaded ferrotherapy by mutually reinforcing ferroptosis and systemic immunity. Upon laser irradiation, the dissolution of the thermal coating, and the introduction of Cu ions and piperazine-erastin (PE) simultaneously induce oxidative stress by reactive oxygen species (ROS)/lipid peroxide (LPO) accumulation and deplete cystine-glutamate transporter (xCT)/GSH. The onset of oxidative stress-mediated ferroptosis is thus achieved, and ICD is triggered, significantly promoting cytotoxic T-cell (CTL) infiltration for IFN-γ secretion. Furthermore, IFN-γ induces immunogenic tumor ferroptosis by inhibiting xCT-antioxidant pathways and enhancing the ACSL4-fatty acid recruitment pathway, which further promotes sensitivity to ferroptosis in cells. These HCuS nanocomposites combined with aPD-L1 effectively in inhibiting tumor metastasis and recurrence. Importantly, these cascade ferrotherapy results broadens the application of HCuS biomaterials.

Iron-based nanoscale coordination polymers synergistically induce immunogenic ferroptosis by blocking dihydrofolate reductase for cancer immunotherapy

Iron is indispensable for cancer cell survival and cancer cells are more vulnerable to ferroptosis than normal cells. Ferroptosis holds promise for overcoming chemoresistance and inducing tumor immunogenic cell death, which offers new possibilities for cancer immunotherapy. However, the prevalence of immunogenic ferroptosis in cancer cells is diminished because of the high levels of reducing substances within tumor microenvironments. Ferroptosis-needed iron is overdose for livings, which is also an obstacle for effective immune responses. In this study, we construct self-assembled carrier-free nanoscale coordination polymers based on iron and methotrexate (MFe-NCPs). The low-dose-iron-induced immunogenic ferroptosis is obviously enhanced by methotrexate via inhibiting dihydrofolate reductase and abating substance reduction, respectively. Of note, MFe-NCPs sequentially promoted antigen presentation, immune activation, T cell infiltration and boosted the therapeutic effect of immune checkpoint blockade therapy.

Inhibition of ALG3 stimulates cancer cell immunogenic ferroptosis to potentiate immunotherapy

Immune checkpoint blockade therapy has drastically improved the prognosis of certain advanced-stage cancers. However, low response rates and immune-related adverse events remain important limitations. Here, we report that inhibiting ALG3, an a-1,3-mannosyltransferase involved in protein glycosylation in the endoplasmic reticulum (ER), can boost the response of tumors to immune checkpoint blockade therapy. Deleting N-linked glycosylation gene ALG3 in mouse cancer cells substantially attenuates their growth in mice in a manner depending on cytotoxic T cells. Furthermore, ALG3 inhibition or N-linked glycosylation inhibitor tunicamycin treatment synergizes with anti-PD1 therapy in suppressing tumor growth in mouse models of cancer. Mechanistically, we found that inhibiting ALG3 induced deficiencies of post-translational N-linked glycosylation modification and led to excessive lipid accumulation through sterol-regulated element-binding protein (SREBP1)-dependent lipogenesis in cancer cells. N-linked glycosylation deficiency-mediated lipid hyperperoxidation induced immunogenic ferroptosis of cancer cells and promoted a pro-inflammatory microenvironment, which boosted anti-tumor immune responses. In human subjects with cancer, elevated levels of ALG3 expression in tumor tissues are associated with poor patient survival. Taken together, we reveal an unappreciated role of ALG3 in regulating tumor immunogenicity and propose a potential therapeutic strategy for enhancing cancer immunotherapy.