The Potential Revolution of Cancer Treatment with CRISPR Technology.

Immuno-oncology (IO) and targeted therapies, such as small molecule inhibitors, have changed the landscape of cancer treatment and prognosis; however, durable responses have been difficult to achieve due to tumor heterogeneity, development of drug resistance, and adverse effects that limit dosing and prolonged drug use. To improve upon the current medicinal armamentarium, there is an urgent need for new ways to understand, reverse, and treat carcinogenesis. Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein (Cas) 9 is a powerful and efficient tool for genome editing that has shown significant promise for developing new therapeutics. While CRISPR/Cas9 has been successfully used for pre-clinical cancer research, its use in the clinical setting is still in an early stage of development. The purpose of this review is to describe the CRISPR technology and to provide an overview of its current applications and future potential as cancer therapies.

SP3-Enabled Rapid and High Coverage Chemoproteomic Identification of Cell-State-Dependent Redox-Sensitive Cysteines.

Proteinaceous cysteine residues act as privileged sensors of oxidative stress. As reactive oxygen and nitrogen species have been implicated in numerous pathophysiological processes, deciphering which cysteines are sensitive to oxidative modification and the specific nature of these modifications is essential to understanding protein and cellular function in health and disease. While established mass spectrometry-based proteomic platforms have improved our understanding of the redox proteome, the widespread adoption of these methods is often hindered by complex sample preparation workflows, prohibitive cost of isotopic labeling reagents, and requirements for custom data analysis workflows. Here, we present the SP3-Rox redox proteomics method that combines tailored low cost isotopically labeled capture reagents with SP3 sample cleanup to achieve high throughput and high coverage proteome-wide identification of redox-sensitive cysteines. By implementing a customized workflow in the free FragPipe computational pipeline, we achieve accurate MS1-based quantitation, including for peptides containing multiple cysteine residues. Application of the SP3-Rox method to cellular proteomes identified cysteines sensitive to the oxidative stressor GSNO and cysteine oxidation state changes that occur during T cell activation.

Factors Associated With Hospitalization Among Breast Cancer Patients With COVID-19: A Diverse Multi-Center Los Angeles Cohort Study.

BACKGROUND: The SARS-CoV-2 virus has infected and killed millions of people worldwide. Breast cancer is the most prevalent cancer in women and few studies have investigated the outcomes of patients with a history of breast cancer and COVID-19. We report the clinical outcomes of patients with invasive breast cancer who tested positive for SARS-CoV-2, including hospitalization and death, and evaluate demographic and cancer-related factors associated with these outcomes. PATIENTS: Patients with a history of invasive breast cancer and positive SARS-CoV-2 test from January 1 to December 31, 2020 at two large, academic Los Angeles health systems were included. METHODS: Retrospective chart review of the electronic medical record was performed. Data for demographic and cancer-related factors were manually abstracted. Relationships between outcomes and clinical variables were evaluated using Fisher's exact test and linear regression analysis. RESULTS: Among a total of 132 patients, 40 (30.3%) were hospitalized, while 11 (8.3%) required intensive care support, and 8 patients (6.1%) died. Older age and presence of one or more additional comorbidities were associated with hospitalization and death (P = .010, P = .003, P = .034, P < .001). Hispanic/Latinx ethnicity was associated with hospitalization (P = .047). Cancer treatment was not associated with hospitalization or death. CONCLUSION: In our diverse, multi-center, breast cancer cohort, Hispanic/Latinx ethnicity, older age and presence of other comorbidities were associated with worse outcomes from COVID-19. Breast cancer treatment, including surgery, radiation, systemic therapy, and endocrine therapy, was not associated with hospitalization in our cohort. Further studies are needed to explore the relationship between breast cancer and COVID-19 outcomes.

Synthesis of Enantioenriched gem-Disubstituted 4-Imidazolidinones by Palladium-Catalyzed Decarboxylative Asymmetric Allylic Alkylation.

A variety of enantioenriched gem-disubstituted 4-imidazolidinones were prepared in up to >99% yield and 95% ee by the Pd-catalyzed decarboxylative asymmetric allylic alkylation of imidazolidinone-derived ß-amidoesters. In the process of preparing these substrates, a rapid synthetic route to 4-imidazolidinone derivatives was developed, beginning from 2-thiohydantoin. The orthogonality of the benzoyl imide and tert-butyl carbamate groups used to protect these nitrogen-rich products was demonstrated, enabling potential applications in drug design.

Palladium-Catalyzed Decarboxylative Asymmetric Allylic Alkylation of 1,4-Diazepan-5-ones.

We report the palladium-catalyzed asymmetric allylic alkylation of 1,4-diazepan-5-ones. This reaction proceeds smoothly to give gem-disubstituted diazepanone heterocycles bearing various functional groups in up to >99% yield and up to 95% ee. An electron-rich p-anisoyl lactam protecting group and the use of a nonpolar solvent proved crucial to obtaining high enantioselectivity in most cases. Additionally, we demonstrate the use of our methodology in the synthesis of a gem-disubstituted analogue of the FDA-approved anti-insomnia drug suvorexant.

Incorporation of a chiral gem-disubstituted nitrogen heterocycle yields an oxazolidinone antibiotic with reduced mitochondrial toxicity.

gem-Disubstituted N-heterocycles are rarely found in drugs, despite their potential to improve the drug-like properties of small molecule pharmaceuticals. Linezolid, a morpholine heterocycle-containing oxazolidinone antibiotic, exhibits significant side effects associated with human mitochondrial protein synthesis inhibition. We synthesized a gem-disubstituted linezolid analogue that when compared to linezolid, maintains comparable (albeit slightly diminished) activity against bacteria, comparable in vitro physicochemical properties, and a decrease in undesired mitochondrial protein synthesis (MPS) inhibition. This research contributes to the structure-activity-relationship data surrounding oxazolidinone MPS inhibition, and may inspire investigations into the utility of gem-disubstituted N-heterocycles in medicinal chemistry.

Enantioselective synthesis of gem-disubstituted N-Boc diazaheterocycles via decarboxylative asymmetric allylic alkylation.

An enantioselective synthesis of diverse N4-Boc-protected α,α-disubstituted piperazin-2-ones using the palladium-catalyzed decarboxylative allylic alkylation reaction has been achieved. Using a chiral Pd-catalyst derived from an electron deficient PHOX ligand, chiral piperazinones are synthesized in high yields and enantioselectivity. The chiral piperazinone products can be deprotected and reduced to valuable gem-disubstituted piperazines. This reaction is further extended to enable the enantioselective synthesis of α,α-disubstituted tetrahydropyrimidin-2-ones, which are hydrolyzed into corresponding chiral ß2,2-amino acids.

Structure-based design, synthesis, and characterization of dual hotspot small-molecule HIV-1 entry inhibitors.

Cellular infection by HIV-1 is initiated with a binding event between the viral envelope glycoprotein gp120 and the cellular receptor protein CD4. The CD4-gp120 interface is dominated by two hotspots: a hydrophobic gp120 cavity capped by Phe43(CD4) and an electrostatic interaction between residues Arg59(CD4) and Asp368(gp120). The CD4 mimetic small-molecule NBD-556 (1) binds within the gp120 cavity; however, 1 and related congeners demonstrate limited viral neutralization breadth. Herein, we report the design, synthesis, characterization, and X-ray structures of gp120 in complex with small molecules that simultaneously engage both binding hotspots. The compounds specifically inhibit viral infection of 42 tier 2 clades B and C viruses and are shown to be antagonists of entry into CD4-negative cells. Dual hotspot design thus provides both a means to enhance neutralization potency of HIV-1 entry inhibitors and a novel structural paradigm for inhibiting the CD4-gp120 protein-protein interaction.