EGFR tyrosine kinase inhibitor (EGFR-TKI) has been used successfully in clinic for the treatment of solid tumors. In the present study, we reported the discovery of from our in-house diverse compound library, which was validated to be a potent and selective EGFR-TKI. showed excellent inhibitory activities against EGFR (IC = 0.81 nmol/L), EGFR (IC = 1.2 nmol/L) and EGFR (IC = 1.1 nmol/L), but was less effective or even inactive against other nine kinases. also displayed excellent antiproliferative activities against a panel of human cancer cell lines, and exhibited the ability to reduce colony formation and wound healing the same as gefitinib. We found that upon oral administration showed better anti-tumor activity in A431 bearing xenograft mouse models compared to gefitinib. In addition, showed better intestinal absorption than gefitinib and had favorable pharmacokinetic properties and microsomal metabolic stability in different species. These studies indicate that has strong antitumor activity and , and could be used for the development of anti-lung cancer agent targeting EGFR.

Targeting immune checkpoints such as programmed cell death protein 1 (PD-1) and programmed death ligand-1 (PD-L1) have been approved for treating melanoma, gastric cancer (GC) and bladder cancer with clinical benefit. Nevertheless, many patients failed to respond to anti-PD-1/PD-L1 treatment, so it is necessary to seek an alternative strategy for traditional PD-1/PD-L1 targeting immunotherapy. Here with the data from The Cancer Genome Atlas (TCGA) and our in-house tissue library, PD-L1 expression was found to be positively correlated with the expression of ubiquitin-specific processing protease 7 (USP7) in GC. Furthermore, USP7 directly interacted with PD-L1 in order to stabilize it, while abrogation of USP7 attenuated PD-L1/PD-1 interaction and sensitized cancer cells to T cell killing