Targeting the myeloid checkpoint receptor SIRPα potentiates innate and adaptive immune responses to promote anti-tumor activity.

Background: Signal regulatory protein α (SIRPα) is a myeloid-lineage inhibitory receptor that restricts innate immunity through engagement of its cell surface ligand CD47. Blockade of the CD47-SIRPα interaction synergizes with tumor-specific antibodies and T-cell checkpoint inhibitors by promoting myeloid-mediated antitumor functions leading to the induction of adaptive immunity. Inhibition of the CD47-SIRPα interaction has focused predominantly on targeting CD47, which is expressed ubiquitously and contributes to the accelerated blood clearance of anti-CD47 therapeutics.

Discovery of high affinity, pan-allelic, and pan-mammalian reactive antibodies against the myeloid checkpoint receptor SIRPα.

Targeting the CD47-signal-regulatory protein α (SIRPα) pathway represents a novel therapeutic approach to enhance anti-cancer immunity by promoting both innate and adaptive immune responses. Unlike CD47, which is expressed ubiquitously, SIRPα expression is mainly restricted to myeloid cells and neurons. Therefore, compared to CD47-targeted therapies, targeting SIRPα may result in differential safety and efficacy profiles, potentially enabling lower effective doses and improved pharmacokinetics and pharmacodynamics.

ALX148 blocks CD47 and enhances innate and adaptive antitumor immunity with a favorable safety profile.

CD47 is a widely expressed cell surface protein that functions as an immune checkpoint in cancer. When expressed by tumor cells, CD47 can bind SIRPα on myeloid cells, leading to suppression of tumor cell phagocytosis and other innate immune functions. CD47-SIRPα signaling has also been implicated in the suppression of adaptive antitumor responses, but the relevant cellular functions have yet to be elucidated.

Rationally Designed PI3Kα Mutants to Mimic ATR and Their Use to Understand Binding Specificity of ATR Inhibitors.

ATR, a protein kinase in the PIKK family, plays a critical role in the cell DNA-damage response and is an attractive anticancer drug target. Several potent and selective inhibitors of ATR have been reported showing significant antitumor efficacy, with most advanced ones entering clinical trials. However, due to the absence of an experimental ATR structure, the determinants contributing to ATR inhibitors' potency and specificity are not well understood.

Expression, purification and characterization of inactive and active forms of ERK2 from insect expression system.

Extracellular signal-regulated kinase 2 (ERK2) is a serine/threonine protein kinase involved in many cellular programs, such as cell proliferation, differentiation, motility and programed cell-death. It is therefore considered an important target in the treatment of cancer. In an effort to support biochemical screening and small molecule drug discovery, we established a robust system to generate both inactive and active forms of ERK2 using insect expression system.

Structure-Based Drug Design of Novel Potent and Selective Tetrahydropyrazolo[1,5-a]pyrazines as ATR Inhibitors.

A saturation strategy focused on improving the selectivity and physicochemical properties of ATR inhibitor HTS hit 1 led to a novel series of highly potent and selective tetrahydropyrazolo[1,5-a]pyrazines. Use of PI3Kα mutants as ATR crystal structure surrogates was instrumental in providing cocrystal structures to guide the medicinal chemistry designs. Detailed DMPK studies involving cyanide and GSH as trapping agents during microsomal incubations, in addition to deuterium-labeled compounds as mechanistic probes uncovered the molecular basis for the observed CYP3A4 TDI in the series.

Pim2 is required for maintaining multiple myeloma cell growth through modulating TSC2 phosphorylation.

Multiple myeloma (MM) is the second most common hematologic malignancy. Despite recent treatment advances, it remains incurable. Here, we report that Pim2 kinase expression is highly elevated in MM cells and demonstrate that it is required for MM cell proliferation.

High-level soluble expression, purification and characterization of active human midkine from Escherichia coli.

Midkine (MDK) belongs to a class of heparin-binding growth factors and is highly expressed in a number of cancers. MDK is a cysteine-rich 13 kDa protein containing five disulfide bonds. In this study, we expressed recombinant human MDK (rhMDK) in Escherichia coli Origami 2 (DE3) strain, which carries a (trxB(-)/gor(522)(-)) double mutation.

Identification of novel small-molecule inhibitors for human transketolase by high-throughput screening with fluorescent intensity (FLINT) assay.

The metabolic enzyme transketolase (TK) plays a crucial role in tumor cell nucleic acid synthesis, using glucose through the elevated nonoxidative pentose phosphate pathway (PPP). Identification of inhibitors specifically targeting TK and preventing the nonoxidative PPP from generating the RNA ribose precursor, ribose-5-phosphate, provides a novel approach for developing effective anticancer therapeutic agents. The full-length human transketolase gene was cloned and expressed in Escherichia coli and the recombinant human transketolase protein purified to homogeneity.

Deacetoxycephalosporin C synthase isozymes exhibit diverse catalytic activity and substrate specificity.

The biosynthesis of cephalosporins involving a thiozolidine ring expansion is catalyzed by deacetoxycephalosporin C synthase (DAOCS). In this study, three DAOCS isozymes were cloned and expressed as active enzymes together with Streptomyces jumonjinensis DAOCS that was newly isolated and partially characterized. The enzymes showed excellent substrate conversion for penicillin G, phenethicillin, ampicillin and carbenicillin, but they were less effective in the ring expansion of penicillin V, amoxicillin and metampicillin.