Design, Synthesis, and Biological Evaluation of Potent and Selective PROTAC Degraders of Oncogenic KRASG12D.

KRASG12D, the most frequent KRAS oncogenic mutation, is a promising target for cancer therapy. Herein, we report the design, synthesis, and biological evaluation of a series of KRASG12D PROTACs by connecting the analogues of MRTX1133 and the VHL ligand. Structural modifications of the linker moiety and KRAS inhibitor part suggested a critical role of membrane permeability in the degradation activity of the KRASG12D PROTACs. Mechanism studies with the representative compound 8o demonstrated that the potent, rapid, and selective degradation of KRASG12D induced by 8o was via a VHL- and proteasome-dependent manner. This compound selectively and potently suppressed the growth of multiple KRASG12D mutant cancer cells, displayed favorable pharmacokinetic and pharmacodynamic properties in mice, and showed significant antitumor efficacy in the AsPC-1 xenograft mouse model. Further optimization of 8o appears to be promising for the development of a new chemotherapy for KRASG12D-driven cancers as the complementary therapeutic strategy to KRAS inhibition.

Design, Synthesis, and Bioevaluation of Pyrido[2,3-d]pyrimidin-7-ones as Potent SOS1 Inhibitors.

The use of small molecular modulators to target the guanine nucleotide exchange factor SOS1 has been demonstrated to be a promising strategy for the treatment of various KRAS-driven cancers. In the present study, we designed and synthesized a series of new SOS1 inhibitors with the pyrido[2,3-d]pyrimidin-7-one scaffold. One representative compound 8u showed comparable activities to the reported SOS1 inhibitor BI-3406 in both the biochemical assay and the 3-D cell growth inhibition assay. Compound 8u obtained good cellular activities against a panel of KRAS G12-mutated cancer cell lines and inhibited downstream ERK and AKT activation in MIA PaCa-2 and AsPC-1 cells. In addition, it displayed synergistic antiproliferative effects when used in combination with KRAS G12C or G12D inhibitors. Further modifications of the new compounds may give us a promising SOS1 inhibitor with favorable druglike properties for use in the treatment of KRAS-mutated patients.

Toward evaluation of multiresolution cortical thickness estimation with FreeSurfer, MaCRUISE, and BrainSuite.

Advances in Magnetic Resonance Imaging hardware and methodologies allow for promoting the cortical morphometry with submillimeter spatial resolution. In this paper, we generated 3D self-enhanced high-resolution (HR) MRI imaging, by adapting 1 deep learning architecture, and 3 standard pipelines, FreeSurfer, MaCRUISE, and BrainSuite, have been collectively employed to evaluate the cortical thickness. We systematically investigated the differences in cortical thickness estimation for MRI sequences at multiresolution homologously originated from the native image. It has been revealed that there systematically exhibited the preferences in determining both inner and outer cortical surfaces at higher resolution, yielding most deeper cortical surface placements toward GM/WM or GM/CSF boundaries, which directs a consistent reduction tendency of mean cortical thickness estimation; on the contrary, the lower resolution data will most probably provide a more coarse and rough evaluation in cortical surface reconstruction, resulting in a relatively thicker estimation. Although the differences of cortical thickness estimation at the diverse spatial resolution varied with one another, almost all led to roughly one-sixth to one-fifth significant reduction across the entire brain at the HR, independent to the pipelines we applied, which emphasizes on generally coherent improved accuracy in a data-independent manner and endeavors to cost-efficiency with quantitative opportunities.

Design, synthesis and structure-activity relationship studies of pyrido[2,3-d]pyrimidin-7-ones as potent Janus Kinase 3 (JAK3) covalent inhibitors.

Aberrantly activated Janus kinase 3 (JAK3) has been constantly detected in various immune disorders and hematopoietic cancers, suggesting its potential of being an attractive therapeutic target for these indications. Clinical benefits of drugs selectively targeting JAK3 versus pan-JAK inhibitors remain unclear. In this study, we report the design and synthesis of a new series of JAK3 covalent inhibitors with a pyrido[2,3-d]pyrimidin-7-one scaffold. After the extensive SAR study, compound 10f emerged to be the most potent JAK3 inhibitor with an IC50 value of 2.0 nM. It showed excellent selectively proliferation inhibitory activity against U937 cells harboring JAK3 M511I mutation, while remained weakly active to the other tested cancer cells. Compound 10f also dose-dependently inhibited the phosphorylation of JAK3 and its downstream signal STAT5 in U937 cells. Taken together, 10f may serve as a promising tool molecule for treating cancers with aberrantly activated JAK3.

Learning a Phenotypic-Attribute Attentional Brain Connectivity Embedding for ADHD Classification using rs-fMRI.

Automated diagnosis of Attention Deficit/Hyperactivity Disorder (ADHD) from brain's functional imaging has gained more interest due to its high prevalence rates among children. While phenotypic information, such as age and gender, is known to be important in diagnosing ADHD and critically affects the representation derived from fMRI brain images, limited studies have integrated phenotypic information when learning discriminative embedding from brain imaging for such an automatic classification task. In this work, we propose to integrate age and gender attributes through attention mechanism that is jointly optimized when learning a brain connectivity embedding using convolutional variational autoencoder derived from resting state functional magnetic resonance imaging (rs-fMRI) data. Our proposed framework achieves a state-of-the-art average of 86.22% accuracy in ADHD vs. typical develop control (TDC) binary classification task evaluated across five public ADHD-200 competition datasets. Furthermore, our analysis points out that there are insufficient linked connections to the brain region of precuneus in the ADHD group.

Discovery and optimization of 3-(2-(Pyrazolo[1,5-a]pyrimidin-6-yl)ethynyl)benzamides as novel selective and orally bioavailable discoidin domain receptor 1 (DDR1) inhibitors.

Discoidin domain receptor 1 (DDR1) is an emerging potential molecular target for new anticancer drug discovery. We have discovered a series of 3-(2-(pyrazolo[1,5-a]pyrimidin-6-yl) ethynyl)benzamides that are selective and orally bioavailable DDR1 inhibitors. The two most promising compounds (7rh and 7rj) inhibited the enzymatic activity of DDR1, with IC50 values of 6.8 and 7.0 nM, respectively, but were significantly less potent in suppressing the kinase activities of DDR2, Bcr-Abl, and c-Kit. Further study revealed that 7rh bound with DDR1 with a Kd value of 0.6 nM, while it was significantly less potent to the other 455 kinases tested. The S(35) and S(10) selectivity scores of 7rh were 0.035 and 0.008, respectively. The compounds also potently inhibited the proliferation of cancer cells expressing high levels of DDR1 and strongly suppressed cancer cell invasion, adhesion, and tumorigenicity. Preliminary pharmacokinetic studies suggested that they possessed good PK profiles, with oral bioavailabilities of 67.4% and 56.2%, respectively.