Arginine methylation is a critical post-translational modification that plays multifaceted biological functions. However, the manipulation of protein arginine methylation largely depends on genetic or pharmaceutic inhibition of the regulatory enzymes, protein arginine methyltransferases (PRMTs), or non-methylation substitution of corresponding arginine residue to lysine or alanine of protein of interest (POI), which inevitably affects other substrates, or disrupts the structure of POI. Thus, it urges an approach to specifically modulate the arginine methylation of a POI under physiological conditions. To this end, we report the discovery of a methylation tagging system (MeTAG), that enables targeted modification of protein arginine methylation. Through bridging the methyltransferase PRMT5 proximity to a POI, MeTAG facilitates the arginine methylation of POIs, including known arginine methylated proteins, androgen receptor (AR) and protein kinase B (AKT), as well as a neo-substrate E1A binding protein (p300), in a reversible and PRMT5-dependent manner. Moreover, MeTAG can regulate downstream signaling in a methylation dependent manner, leading to downregulation of PSMA mRNA level and activation of AKT. Therefore, MeTAG represents a feasible approach to modulate protein methylation and thereby perturbs protein function in biological and therapeutic contexts.

Objective    To explore the short-term efficacy and safety of pembrolizumab combined with chemotherapy in the neoadjuvant treatment of non-small cell lung cancer. Methods    The clinical data of 11 male patients with non-small cell lung cancer who underwent pembrolizumab combined with neoadjuvant chemotherapy in the Department of Thoracic Surgery, the First Affiliated Hospital of Xi'an Jiaotong University from December 2019 to June 2021 were retrospectively analyzed. The average age of the patients was 52.0-79.0 (62.0±6.9) years. The imaging data and pathological changes before and after neoadjuvant treatment were compared, and adverse reactions during neoadjuvant treatment were recorded. Objective remission rate (ORR) and main pathological remission rate (MPR) and pathological complete remission rate (pCR) were the main observation endpoints. Results    After preoperative neoadjuvant therapy with pembrolizumab combined with platinum or paclitaxel, all patients successfully underwent thoracoscopic radical resection of lung cancer. The ORR was 72.7%, and the MPR was 81.8%. Among them, 45.5% of patients achieved pCR. The main adverse reactions were hypoalbuminemia, decreased appetite and nausea. The mortality rate within 30 days after surgery was 0, and no tumor metastasis was observed. Conclusion    Pembrolizumab combined with neoadjuvant chemotherapy is safe and feasible to treat non-small cell lung cancer, and the short-term efficacy is beneficial.