In the tumour microenvironment (TME), immunogenic cell death (ICD) plays a major role in stimulating the dysfunctional antitumour immune system. Chronic exposure of damage‐associated molecular patterns (DAMPs) attracts receptors and ligands on dendritic cells (DCs) and activates immature DCs to transition to a mature phenotype, which promotes the processing of phagocytic cargo in DCs and accelerates the engulfment of antigenic components by DCs. Consequently, via antigen presentation, DCs stimulate specific T cell responses that kill more cancer cells. The induction of ICD eventually results in long‐lasting protective antitumour immunity. Through the exploration of ICD inducers, recent studies have shown that there are many novel modalities with the ability to induce immunogenic cancer cell death. In this review, we mainly discussed and summarized the emerging methods for inducing immunogenic cancer cell death. Concepts and molecular mechanisms relevant to antitumour effects of ICD are also briefly discussed.

During tumorigenesis and development, participation of the tumor microenvironment is not negligible. As an important component in the tumor microenvironment, mesenchymal stem cells (MSCs) have been corroborated to mediate proliferation, metastasis, and drug resistance in many cancers, including osteosarcoma. What’s more, because of tumor site tropism, MSCs can be engineered to be loaded with therapeutic agents so that drugs can be precisely delivered to tumor lesions. In this review, we mainly discuss recent advances concerning the functions of MSCs in osteosarcoma and their possible clinical applications in the future.

Osteosarcoma (OS) is a common malignant cancer in children and adolescents and has a cure rate that has not improved in the last two decades. CYT997 (lexibulin) is a novel potent microtubule-targeting agent with various anticancer activities, such as proliferation inhibition, vascular disruption, and cell cycle arrest and apoptosis induction, in multiple cancers. However, the direct cytotoxic mechanisms of CYT997 have not yet been fully characterized. We evaluated apoptosis and autophagy in human osteosarcomas after treatment with CYT997 and investigated the underlying mechanisms. To explore relationships, we used the reactive oxygen species (ROS) scavenger N-acetyl cysteine (NAC), PERK inhibitor GSK2606414, ERO1 inhibitor EN460 and mitochondrial targeted protection peptide elamipretide. BALB/c-nu mice were inoculated with 143B tumor cells to investigate the in vivo effect of CYT997. We explored the efficacy and mechanism of CYT997 in osteosarcoma (OS) in vitro and in vivo and demonstrated that CYT997 potently suppresses cell viability and induces apoptosis and autophagy. CYT997 triggered production of ROS and exerted lethal effects via endoplasmic reticulum (ER) stress in OS cells. NAC attenuated these effects. The PERK inhibitor GSK2606414, which can block the ER stress pathway, reduced ROS production and enhanced cell viability. Moreover, activation of ERO1 in the ER stress pathway was responsible for inducing ROS production. ROS produced by the mitochondrial pathway also aggravate ER stress. Protection of mitochondria can reduce apoptosis and autophagy. Finally, CYT997 prominently reduced tumor growth in vivo. This study suggests that CYT997 induces apoptosis and autophagy in OS cells by triggering mutually enhanced ER stress and ROS and may thus be a promising agent against OS.

Chimeric antigen receptor‐ (CAR‐) T cell therapy is one of the most recent innovative immunotherapies and is rapidly evolving. Like other technologies, CAR‐T cell therapy has undergone a long development process, and persistent explorations of the actions of the intracellular signaling domain and make several improvements have led to the superior efficacy when anti‐CD19 CAR‐T cell treatments in B cell cancers. At present, CAR‐T cell therapy is developing rapidly, and many clinical trials have been established on a global scale, which has great commercial potential. This review mainly describes the toxicity of CAR‐T cell therapy and the challenges of CAR‐T cells in the treatment of solid tumors, and looks forward to future development and opportunities for immunotherapy and reviews major breakthroughs in CAR‐T cell therapy.