Cancer immune therapy with PD-1-dependent CD137 co-stimulation provides localized tumour killing without systemic toxicity.

Expression of the cell surface receptor CD137 has been shown to enhance anti-cancer T cell function via engagement with its natural ligand 4-1BBL. CD137 ligation with engineered ligands has emerged as a cancer immunotherapy strategy, yet clinical development of agonists has been hindered by either toxicity or limited efficacy. Here we show that a CD137/PD-1 bispecific antibody, IBI319, is able to overcome these limitations by coupling CD137 activation to PD-1-crosslinking. In CT26 and MC38 syngeneic mouse tumour models, IBI319 restricts T cell co-stimulation to PD-1-rich microenvironments, such as tumours and tumour-draining lymph nodes, hence systemic (liver) toxicity arising from generalised T cell activation is reduced. Besides limiting systemic T cell co-stimulation, the anti-PD-1 arm of IBI319 also exhibits checkpoint blockade functions, with an overall result of T and NK cell infiltration into tumours. Toxicology profiling in non-human primates shows that IBI319 is a well-tolerated molecule with IgG-like pharmacokinetic properties, thus a suitable candidate for further clinical development.

CRMP2 is a therapeutic target that suppresses the aggressiveness of breast cancer cells by stabilizing RECK.

Metastatic breast cancer is characterized by high mortality and limited therapeutic target. During tumor metastasis, cytoskeletal reorganization is one of the key steps in the migration and invasion of breast cancer cells. Collapsin response mediator protein 2 (CRMP2) is a cytosolic phosphoprotein that plays an important role in regulating cytoskeletal dynamics. Previous researches have reported that altered CRMP2 expression is associated with breast cancer progression, but the underlying mechanism remains poorly understood. Here, we show that CRMP2 expression is reduced in various subtypes of breast cancers and negatively correlated with lymphatic metastasis. Overexpression of CRMP2 significantly inhibits invasion and stemness in breast cancer cells, while downregulation of CRMP2 promotes cell invasion, which is not required for tubulin polymerization. Mechanistic studies demonstrate that CRMP2 interacts with RECK, prevents RECK degradation, which, in turn, blocks NF-κB and Wnt signaling pathways. Furthermore, we find that phosphorylation of CRMP2 at T514 and S522 remarkably abolishes its functions to bind with RECK and to inhibit cell invasion. Pharmacologic rescue of CRMP2 expression suppressed breast cancer metastasis in vitro and in vivo and stimulated a synergetic effect with FN-1501 that induces CRMP2 dephosphorylation. Collectively, this study highlights the potential of CRMP2 as a therapeutic target in breast cancer metastasis and reveals a distinct mechanism of CRMP2.

Oroxylin A suppresses ACTN1 expression to inactivate cancer-associated fibroblasts and restrain breast cancer metastasis.

Tumor initiation and progression are not only ascribed to the behavior of cancer cells, but also profoundly influenced by the tumor microenvironment. Inside, cancer-associated fibroblasts (CAFs) have become key factors to accelerate growth and metastasis for the abundance in most solid tumors. Our group previously reported that Oroxylin A (OA), a flavone from Scutellaria Baicalensis Georgi, possess the ability to suppress growth and invasion of several tumor cells. However, the regulatory effect of OA on stromal microenvironment is poorly understood. In this study, breast cancer-induced fibroblasts and primary breast CAFs from MMTV-PyMT mice were used to evaluate the influence of OA on the activation of fibroblasts. Results showed that OA could decrease the expression of α-SMA, fibronectin, vimentin and matrix metalloproteinases (MMPs). Thus, OA-deactivated CAFs did not further promote the proliferation and invasion in breast cancer cells. In vivo experiments, OA could also impede tumor metastasis through exhausting progressive CAFs. Mechanically, OA could specifically bind ACTN1 and significantly inhibit its expression to prevent CAF activation. As a consequence, OA could decrease the phosphorylation of FAK and STAT3, and reduce the secretion of CCL2 in CAFs. Altogether, OA could remodel stromal microenvironment and it is a potential therapeutic agent in breast cancer.

The Application of Ferroptosis in Diseases.

Ferroptosis is a new kind of regulated cell death that is characterized by highly iron-dependent lipid peroxidation. Ferroptosis involves various biology processes, such as iron metabolism, lipid metabolism, oxidative stress and biosynthesis of nicotinamide adenine dinucleotide phosphate (NADPH), glutathione (GSH) and coenzyme Q10 (CoQ10). A growing body of evidence suggests that ferroptosis is associated with cancer and neurodegenerative diseases (Alzheimer's disease, Parkinson's disease and Huntington's disease). This finding has helped develop a novel cytoprotective strategy to protect cells in neurodegenerative, blood and heart diseases by inhibiting ferroptosis. Meanwhile, the selective induction of ferroptosis has been adopted as a potential treatment strategy in some kinds of cancer. This review aims to summarize the mechanism of ferroptosis regulation and relevance to pathological physiology.

Correction to: Artemisinin derivatives inactivate cancer-associated fibroblasts through suppressing TGF-ß signaling in breast cancer.

In the original publication of this article [1], Fig. 3 is wrong, but does not affect discussions and conclusions drawn in the article.

Artemisinin derivatives inactivate cancer-associated fibroblasts through suppressing TGF-ß signaling in breast cancer.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are activated fibroblasts associated with cancer. They have an important role in tumor growth and metastasis. Artemisinin (ART) is a sesquiterpene lactone extracted from Chinese herb qinghao, and artemether (ARM), artesunate (ARS) and dihydroartemisinin (DHA) were synthesized derivatives of artemisinin, which also have anti-malarial and anti-cancer effects such as artemisinin. METHODS: In this study, we investigated the in-vitro and in-vivo effects of artemisinin derivatives on inactivating cancer-associated fibroblasts and uncovered its underlying mechanism. RESULTS: We demonstrated that ARS and DHA could revert L-929-CAFs and CAFs from activated to inactivated state in vitro. Mechanically, ARS and DHA could suppress TGF-ß signaling to inhibit activation of L-929-CAFs and CAFs, and decreased interaction between tumor and tumor microenvironment. The results showed that ARS and DHA could suppress CAFs-induced breast cancer growth and metastasis in the orthotopic model. Conformably, ARS and DHA suppressed TGF-ß signaling to inactivate cancer-associated fibroblasts and inhibit cancer metastasis in vivo. CONCLUSIONS: Artemisinin derivatives are potential therapeutic agents for the treatment of breast cancer.