Cotargeting CDK4/6 and BRD4 Promotes Senescence and Ferroptosis Sensitivity in Cancer.

Unlabelled: Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are approved for breast cancer treatment and show activity against other malignancies, including KRAS-mutant non-small cell lung cancer (NSCLC). However, the clinical efficacy of CDK4/6 inhibitors is limited due to frequent drug resistance and their largely cytostatic effects. Through a genome-wide cDNA screen, we identified that bromodomain-containing protein 4 (BRD4) overexpression conferred resistance to the CDK4/6 inhibitor palbociclib in KRAS-mutant NSCLC cells.

Alanine supplementation exploits glutamine dependency induced by SMARCA4/2-loss.

SMARCA4 (BRG1) and SMARCA2 (BRM) are the two paralogous ATPases of the SWI/SNF chromatin remodeling complexes frequently inactivated in cancers. Cells deficient in either ATPase have been shown to depend on the remaining counterpart for survival. Contrary to this paralog synthetic lethality, concomitant loss of SMARCA4/2 occurs in a subset of cancers associated with very poor outcomes.

Identification and characterization of hippuristanol-resistant mutants reveals eIF4A1 dependencies within mRNA 5' leader regions.

Hippuristanol (Hipp) is a natural product that selectively inhibits protein synthesis by targeting eukaryotic initiation factor (eIF) 4A, a DEAD-box RNA helicase required for ribosome recruitment to mRNA templates. Hipp binds to the carboxyl-terminal domain of eIF4A, locks it in a closed conformation, and inhibits its RNA binding. The dependencies of mRNAs for eIF4A during initiation is contingent on the degree of secondary structure within their 5' leader region.

Tracing MYC Expression for Small Molecule Discovery.

Our inability to effectively "drug" targets such as MYC for therapeutic purposes requires the development of new approaches. We report on the implementation of a phenotype-based assay for monitoring MYC expression in multiple myeloma cells. The open reading frame (ORF) encoding an unstable variant of GFP was engineered immediately downstream of the MYC ORF using CRISPR/Cas9, resulting in co-expression of both proteins from the endogenous MYC locus.

Developing anti-neoplastic biotherapeutics against eIF4F.

Biotherapeutics have revolutionized modern medicine by providing medicines that would not have been possible with small molecules. With respect to cancer therapies, this represents the current sector of the pharmaceutical industry having the largest therapeutic impact, as exemplified by the development of recombinant antibodies and cell-based therapies. In cancer, one of the most common regulatory alterations is the perturbation of translational control.

Foot-and-mouth disease virus leader proteinase: structural insights into the mechanism of intermolecular cleavage.

Translation of foot-and-mouth disease virus RNA initiates at one of two start codons leading to the synthesis of two forms of leader proteinase L(pro) (Lab(pro) and Lb(pro)). These forms free themselves from the viral polyprotein by intra- and intermolecular self-processing and subsequently cleave the cellular eukaryotic initiation factor (eIF) 4 G. During infection, Lb(pro) removes six residues from its own C-terminus, generating sLb(pro).

The leader proteinase of foot-and-mouth disease virus: structure-function relationships in a proteolytic virulence factor.

The leader proteinase (Lpro) of the foot-and-mouth disease virus inhibits the host innate immune response by at least three different mechanisms. The most well-characterised of these is the prevention of the synthesis of cytokines such as interferons immediately after infection, brought about by specific proteolytic cleavage of the eukaryotic initiation factor 4G. This prevents the recruitment of capped cellular mRNA; however, the viral RNA can be translated under these conditions.

Comparison of self-processing of foot-and-mouth disease virus leader proteinase and porcine reproductive and respiratory syndrome virus leader proteinase nsp1α.

The foot-and-mouth disease virus leader proteinase (Lb(pro)) cleaves itself off the nascent viral polyprotein. NMR studies on the monomeric variant Lb(pro) L200F provide structural evidence for intramolecular self-processing. (15)N-HSQC measurements of Lb(pro) L200F showed specifically shifted backbone signals in the active and substrate binding sites compared to the monomeric variant sLb(pro), lacking six C-terminal residues.