Design, synthesis, and evaluation of 4(1H)-quinolinone and urea derivatives as KRASG12C inhibitors with potent antitumor activity against KRAS-mutant non-small cell lung cancer.

KRASG12C is the most prevalent KRAS mutation in non-small cell lung cancer (NSCLC) and has emerged as a promising therapeutic target. Herein, two series of novel 4(1H)-quinolinone and urea compounds were designed based on the reported KRASG12C inhibitor SH-9. Many compounds showed significantly growth inhibitory activity against human NSCLC cells with KRASG12C mutation in cell viability assays. Compound 20a exhibited an IC50 value of 0.5 µM in KRASG12C-mutant NCI-H358 cells with 21-fold selectivity over KRASWT NCI-H2228 cells. LC-MS analysis indicated that compounds 14c, 14h and 20a covalently bound to KRASG12C rather than KRASWT. Moreover, these compounds could remarkably trap KRASG12C in its inactive state by blocking SOS1-mediated GDP/GTP exchange. Furthermore, treatment of NCI-H358 but not NCI-H2228 cells with 20a dose-dependently reduced the phosphorylation of KRAS downstream effectors ERK and AKT. Importantly, 20a significantly inhibited tumor growth in NCI-H358 xenograft models by suppressing KRASG12C signalling. These results indicate that 20a is a promising candidate worthy of further investigation.

Mannose-targeting Concanavalin A-Epirubicin Conjugate for Targeted Intravesical Chemotherapy of Bladder Cancer.

Intravesical instillation of chemotherapeutic drugs such as epirubicin (EPI) is routinely used to prevent tumor recurrence and progression after transurethral resection of bladder tumor. However, the lack of tumor selectivity often causes severe damage to normal bladder urothelium leading to intolerable side effects. Here, we analyzed abnormal changes in glycosylation in bladder cancer and identified mannose as the most aberrantly expressed glycan on the surface of bladder cancer cell lines and human bladder tumor tissues. We then constructed a lectin-drug conjugate by linking concanavalin A (ConA) - a lectin that specifically binds to mannose, with EPI through a pH-sensitive linker. This ConA-EPI conjugate conferred EPI with mannose-targeting ability and selectively internalized cancer cells in vitro. This conjugate showed selective cytotoxicity to cancer cells in vitro and better antitumor activity in an orthotopic mouse model of bladder cancer. Our lectin-drug conjugation strategy makes targeted intravesical chemotherapy of bladder cancer possible.

Design and synthesis of novel 2-arylbenzimidazoles as selective mutant isocitrate dehydrogenase 2 R140Q inhibitors.

A series of novel 2-arylbenzimidazoles have been designed, synthesized and evaluated for their inhibitory activity against IDH2 R140Q mutant. The preliminary results indicated that four compounds 7b, 7c, 7m and 7r displayed the potent inhibitory activity against IDH2 R140Q mutant. Among them, compound 7c showed the highest inhibitory activity, with the IC50 value of 0.26 µM, which was more active than positive control enasidenib. The exquisite selectivity of 7c for IDH2 R140Q mutant isoform was demonstrated by the poor activity against the IDH1 R132C mutant, IDH1 R132H mutant, wild-type IDH1, IDH2 R172K mutant and the wild-type IDH2.