Discovery of Potent and Selective G9a Degraders for the Treatment of Pancreatic Cancer.

G9a, which was initially identified as a histone H3 Lys9 (H3K9) methyltransferase, is potentially an attractive therapeutic target for human cancers. Despite its importance, there is no available selective G9a chemical probe because its homologous protein GLP shares approximately 80% of its sequence with G9a. The development of G9a chemical probes with high selectivity for G9a over GLP is a big challenge but is extremely valuable for understanding G9a-related biology. Herein, we developed a first-in-class selective G9a degrader G9D-4, which induced a dose- and time-dependent G9a degradation without degradation of GLP. G9D-4 exhibited effective antiproliferative activities in a panel of pancreatic cancer cell lines and was able to sensitize KRASG12D mutant pancreatic cancer cells to KRASG12D inhibitor MRTX1133. These data clearly demonstrated the practicality and importance of a selective G9a degrader as a preliminary chemical probe suitable for understanding G9a-related biology and a promising strategy for the treatment of pancreatic cancer.

Switchable Regioselective C-H Activation/Annulation of Acrylamides with Alkynes for the Synthesis of 2-Pyridones.

A catalyst-based switchable regioselective C-H activation/annulation of acrylamides with propargyl carbonates has been developed, delivering C5 or C6 alkenyl substituted 2-pyridones. This robust protocol proceeds with a broad substrate scope and good functional group tolerance under redox-neutral reaction conditions. More significantly, this reaction is highly effective with previously challenging unsymmetrical alkynes, including unbiased alkyl-alkyl substituted alkynes, with perfect and switchable regioselectivity. Additionally, mechanistic studies and DFT calculations were performed to shed light on the switchable regioselectivity.

Discovery of potent PROTAC degraders of Pin1 for the treatment of acute myeloid leukemia.

Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (Pin1) is overexpressed and/or overactivated in many human cancers and has been shown to play a critical role during oncogenesis. Despite the potential of Pin1 as a drug target, its successful targeting has proved to be challenging. We speculate that only blocking the enzymatic function of Pin1 with inhibitors may not be sufficient to lead to a total loss-of-function. Here, we report the discovery of P1D-34, a first-in-class and potent PROTAC degrader of Pin1, which induced Pin1 degradation with a DC50 value of 177 nM and exhibited potent degradation-dependent anti-proliferative activities in a panel of acute myeloid leukemia (AML) cell lines. In contrast, Pin1 inhibitor Sulfopin did not show activity. More significantly, P1D-34 could sensitize Bcl-2 inhibitor ABT-199 in Bcl-2 inhibitor-resistant AML cells, highlighting the potential therapeutic value of targeted Pin1 degradation for Bcl-2 inhibitor-resistant AML treatment. Further mechanism study revealed that P1D-34 led to the up-regulation of ROS pathway and down-regulation of UPR pathway to induce cell DNA damage and apoptosis. Notably, we further demonstrated that treatment with the combination formula of glucose metabolism inhibitor 2-DG and P1D-34 led to a notable synergistic anti-proliferative effect, further expanding its applicability. These data clearly reveal the practicality and importance of PROTAC as a preliminary tool compound suitable for assessment of Pin1-dependent pharmacology and a promising strategy for AML treatment.