Anti-FAP single-chain-antibody fragments(Boehringer Ingelheim/Stuttgart University)

Epidermal growth factor receptor (EGFR)-dependent signaling contributes to the pathophysiology of asthma. However, these findings have not been translated into a clinical application. We recently generated ferritin H-chain protein (FTH1)-based nanoparticles with an anti-EGFR single-chain Fv (anti-EGFR scFv) on the surface of FTH1, namely, anti-EGFR scFv-FTH1/FTH1 nanoparticles. In the present study, we found that these nanoparticles could specifically bind to EGFR-expressing cells, leading to downregulation of EGFR and mucin 5AC (MUC5AC) protein expression and growth suppression of House Dust Mite (HDM)-stimulated human bronchial epithelial 16HBE and lipopolysaccharides (LPS)-activated murine macrophage-like RAW264.7 cells. In vivo, intraperitoneal administration of anti-EGFR scFv-FTH1/FTH1 nanoparticles, but not FTH1 nanoparticles, alleviated the major pathological symptoms including airway hyperresponsiveness, airway inflammation, goblet cell hyperplasia, mucus hyperproduction, and increased release of Th2 cytokines in an allergen ovalbumin (OVA)-induced asthma mouse model. Importantly, during the dosing period these nanoparticles were safe for both heathy and asthmatic mice, and more effective in controlling airway inflammation than cetuximab, an EGFR monoclonal antibody. Altogether, our studies provide insights into the control of airway inflammation for treatment of asthma by targeting EGFR. The similar strategy can be used to fabricate scFv-based recombinant protein nanoparticles for other clinical applications.

Early luminal breast cancer (BC) represents 70% of newly diagnosed BC cases. Among them, small (under 2 cm) BC without lymph node metastasis (classified as T1N0) have been rarely studied, as their prognosis is generally favorable. Nevertheless, up to 5% of luminal T1N0 BC patients relapse with distant metastases that ultimately prove fatal. The aim of our work was to identify the mechanisms involved in metastatic recurrence in these patients.

Our study addresses the role that autonomous and non-autonomous tumor cell features play with regard to distant recurrence in early luminal BC patients. We created a cohort of T1N0 luminal BC patients (tumors between 0.5–2 cm without lymph node metastasis) with metastatic recurrence (“cases”) and corresponding “controls” (without relapse) matched 1:1 on main prognostic factors: age, grade, and proliferation. We deciphered different characteristics of cancer cells and their tumor micro-environment (TME) by deep analyses using immunohistochemistry. We performed in vitro functional assays and highlighted a new mechanism of cooperation between cancer cells and one particular subset of cancer-associated fibroblasts (CAF).

We found that specific TME features are indicative of relapse in early luminal BC. Indeed, quantitative histological analyses reveal that “cases” are characterized by significant accumulation of a particular CAF subset (CAF-S1) and decrease in CD4+T lymphocytes, without any other association with immune cells. In multivariate analysis, TME features, in particular CAF-S1 enrichment, remain significantly associated with recurrence, thereby demonstrating their clinical relevance. Finally, by performing functional analyses, we demonstrated that CAF-S1 pro-metastatic activity is mediated by the CDH11/osteoblast cadherin, consistent with bones being a major site of metastases in luminal BC patients.

This study shows that distant recurrence in T1N0 BC is strongly associated with the presence of CAF-S1 fibroblasts. Moreover, we identify CDH11 as a key player in CAF-S1-mediated pro-metastatic activity. This is independent of tumor cells and represents a new prognostic factor. These results could assist clinicians in identifying luminal BC patients with high risk of relapse. Targeted therapies against CAF-S1 using anti-FAP antibody or CDH11-targeting compounds might help in preventing relapse for such patients with activated stroma.