Haugas, M. | bioRxiv Science

bioRxiv2022

Targeting triple-negative breast cancer with β1-integrin binding aptamer

Targeted therapies have increased the treatment options for triple-negative breast cancer patients. However, the paucity of targetable biomarkers and tumour heterogeneity have limited the ability of precision-guided interventions to live up to their full potential. As affinity targeting ligands, aptamers show high selectivity towards target molecules. Compared to antibodies, aptamers have lower molecular weight, increased stability during transportation, reduced immunogenicity, and increased tissue uptake. Recently, we reported the discovery of GreenB1 aptamer that is internalized in cultured triple-negative MDA-MB-231 human breast cancer cells. We show that the GreenB1 aptamer specifically targets {beta}1-integrin, a protein previously linked to breast cancer cell invasiveness and migration. Aptamer binds to {beta}1-integrin with low nanomolar affinity. GreenB1 homes in the orthotopic 4T1 triple-negative breast cancer lesions modelled in mice. Our findings suggest potential applications for the GreenB1-guided precision agents for the diagnosis and therapy of triple-negative breast cancer.

molecular biology↗

bioRxiv2020

In vivo phage display: identification of organ-specific peptides using deep sequencing and differential profiling across tissues

In vivo phage display is widely used for identification of organ- or disease-specific homing peptides. However, the current in vivo phage biopanning approaches fail to assess biodistribution of specific peptide phages across tissues during the screen, thus necessitating laborious and time-consuming post-screening validation studies on individual peptide phages. Here, we adopted bioinformatics tools used for RNA sequencing for analysis of high throughput sequencing (HTS) data to estimate the representation of individual peptides during biopanning in vivo. The data from in vivo phage screen were analyzed using differential binding - relative representation of each peptide in the target organ vs. in a panel of control organs. Application of this approach in a model study using low-diversity peptide T7 phage library with spiked-in brain homing phage, demonstrated brain-specific differential binding of brain homing phage and resulted in identification of novel lung and brain specific homing peptides. Our study provides a broadly applicable approach to streamline in vivo peptide phage biopanning and to increase its reproducibility and success rate. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=90 SRC="FIGDIR/small/181974v2_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@1853e75org.highwire.dtl.DTLVardef@c7ad8corg.highwire.dtl.DTLVardef@152f4feorg.highwire.dtl.DTLVardef@15261d0_HPS_FORMAT_FIGEXP M_FIG C_FIG In vivo phage display using differential binding approach

molecular biology↗