Deep (phospho)proteomics profiling of pre- treatment needle biopsies identifies signatures of treatment resistance in HER2+ breast cancer

Patients with early-stage HER2-overexpressing breast cancer struggle with treatment resistance in 20%-40% of cases. More information is needed to predict HER2 therapy response and resistance in vivo. In this study, we perform (phospho)proteomics analysis of pre-treatment HER2+ needle biopsies of early-stage invasive breast cancer to identify molecular signatures predictive of treatment response to trastuzumab, pertuzumab, and chemotherapy. Our data show that accurate quantification of the estrogen receptor (ER) and HER2 biomarkers, combined with the assessment of associated biological features, has the potential to enable better treatment outcome prediction. In addition, we identify cellular mechanisms that potentially precondition tumors to resist therapy. We find proteins with expression changes that correlate with resistance and constitute to a strong predictive signature for treatment success in our patient cohort. Our results highlight the multifactorial nature of drug resistance in vivo and demonstrate the necessity of deep tumor profiling.

High-throughput macromolecular polymorph screening via an NMR and X-ray powder diffraction synergistic approach: the case of human insulin co-crystallized with resorcinol derivatives

Regular injections of insulin provide life-saving benefits to millions of diabetics. Apart from native insulin and insulin analogue formulations, microcrystalline insulin suspensions are also commercially available. The onset of action of the currently available basal insulins relies on the slow dissociation of insulin hexamers in the subcutaneous space due to the strong binding of small organic ligands. With the aim of identifying insulin–ligand complexes with enhanced pharmacokinetic and pharmacodynamic profiles, the binding affinity of two resorcinol-based molecules (4-chlororesorcinol and 4-bromoresorcinol) and the structural characteristics of insulin upon co-crystallization with them were investigated in the present study. `In solution' measurements were performed via saturation transfer difference (STD) NMR. Co-crystallization upon pH variation resulted in the production of polycrystalline precipitates, whose structural characteristics (i.e. unit-cell symmetry and dimension) were assessed. In both cases, different polymorphs (four and three, respectively) of monoclinic symmetry (P21 and C2 space groups) were identified via X-ray powder diffraction. The results demonstrate the efficiency of a new approach that combines spectroscopy and diffraction techniques and provides an innovative alternative for high-throughput examination of insulin and other therapeutic proteins.