Simultaneous quantification of antibody-RNA conjugates and the transcriptome by single cell RNA-sequencing
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ABSTRACT: Undifferentiated and differentiated Keratinocytes (AG1478 treated) were stained with antibody-RNA conjugates (targeting EGFR and ITGA6) to measure protein-based differentiation changes in conjunction with single-cell transcriptomics.
Project description:Undifferentiated and differentiated Keratinocytes (AG1478 treated) were stained with antibody-RNA conjugates to measure protein-based diffrentiation changes in conjunction with single-cell transcriptomics. The cells were crosslinked and stained according to the RAID procedure to allow intracellular immunostaining. Antibodies used in this experiment are (TGM1, NOTCH1, KLK6, JAG1, phospho-RPS6, phospho-FAK).
Project description:EGFR expression in primary mammary tumors predicts for decrease patient surival, but targeted EGFR inhibitors have failed to improve patient outcomes. To identifiy mediators of resistance to EGFR inhibition in breast cancer, normal murine mammary gland (NMuMG) cells specifcally transformed by overexpression of EGFR (NME) were cultured under 3D conditions in the presence of the EGFR inhibitor AG1478. Using this approach we were able to isolate a cell conlony that demonstrated sponaneous resistance to inhibition of EGFR. These AG1478 resistant (AGR) cells were expanded in vitro and analysed by microarray.
Project description:Objectives Pyrrolobenzodiazepine (PBD) dimers, tethered through inert propyldioxy or pentyldioxy linkers, possess potent bactericidal activity against a range of Gram-positive bacteria by virtue of their capacity to cross-link duplex DNA in sequence-selective fashion. Here we attempt to improve the antibacterial activity and cytotoxicity profile of PBD-containing conjugates by extension of dimer linkers and replacement of one PBD unit with phenyl-substituted or benzo-fused heterocycles that facilitate non-covalent interactions with duplex DNA. Methods DNase I footprinting was used to identify high-affinity DNA binding sites. A staphylococcal gene microarray was used to assess epidemic methicillin-resistant Staphylococcus aureus 16 phenotypes induced by PBD conjugates. Molecular dynamics simulations were employed to investigate the accommodation of compounds within the DNA helix. Results Increasing the length of the linker in PBD dimers led to a progressive reduction in antibacterial activity, but not in their cytotoxic capacity. Complex patterns of DNA binding were noted for extended PBD dimers. Modelling of DNA strand cross-linking by PBD dimers indicated distortion of the helix. A majority (26 of 43) of PBD-biaryl conjugates possessed potent antibacterial activity with little or no helical distortion and a more favourable cytotoxicity profile. Bactericidal activity of PBD-biaryl conjugates was determined by inability to excise covalently bound drug molecules from bacterial duplex DNA. Conclusions PBD-biaryl conjugates have a superior antibacterial profile compared with PBD dimers such as ELB-21. We have identified six PBD-biaryl conjugates as potential drug development candidates. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-118]
Project description:Approximately 15% of lung cancer cases are not associated with smoking and show molecular and clinical characteristics distinct from those in smokers. Epidermal growth factor receptor (EGFR) gene mutations, which are correlated with sensitivity to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), are more frequent in never-smoker lung cancers. In this study, microRNA (miRNA) expression profiling of 28 never-smoker lung cancer cases identified aberrantly expressed miRNAs, which were much fewer than in lung cancers of smokers and included miRNAs previously identified (e.g., upregulated miR-21) and unidentified (e.g., downregulated miR-138) in those smoker cases. The changes in expression of some of these miRNAs were more remarkable in cases with EGFR mutations than in those without: the most upregulated miRNA, miR-21, was more abundant in cancers with EGFR mutation. A significant correlation between phosphorylated-EGFR (p-EGFR) and miR-21 levels in lung carcinoma cell lines and the suppression of miR-21 by an EGFR-TKI, AG1478, suggested that the EGFR signaling pathway positively regulated miR-21 expression. In a never-smoker-derived lung adenocarcinoma cell line H3255 with mutant EGFR and high levels of p-EGFR and miR-21, antisense inhibition of miR-21 enhanced AG1478-induced apoptosis. In a never-smoker-derived adenocarcinoma cell line H441 with wild-type EGFR, the antisense miR-21 not only showed the additive effect with AG1478 but also induced apoptosis by itself. These results suggest that aberrantly increased expression of miR-21, which is further enhanced by the activated EGFR signaling pathway, plays a critical role in lung carcinogenesis in never-smokers and is a potential therapeutic target in both EGFR mutant and wild-type cases.
Project description:Antibody-drug conjugates (ADCs) are a rapidly developing therapeutic approach in cancer treatment that has shown remarkable efficacy in breast cancer. Despite the promising efficacy of anti-HER2 ADCs, many patients are still experiencing disease progression under treatment. Here, by analyzing the transcriptome data from patient-derived organoid models, I-SPY2 trial, and resistant cell lines, we identified that SNX10 deficiency conferred anti-HER2 ADCs resistance. Low levels of SNX10 attenuated HER2 recycling and promoted HER2 trafficking into lysosomes. We also noticed that the lack of interaction between SNX10 and the transcription factor STAT1 inhibited its activation, while STAT1 binds to the promoter region of RAB11A and regulates its transcription. Thus, the lack of SNX10 inhibited HER2 recycling by downregulating RAB11A, decreased cell-surface HER2, and caused anti-HER2 ADC resistance.
Project description:Approximately 15% of lung cancer cases are not associated with smoking and show molecular and clinical characteristics distinct from those in smokers. Epidermal growth factor receptor (EGFR) gene mutations, which are correlated with sensitivity to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), are more frequent in never-smoker lung cancers. In this study, microRNA (miRNA) expression profiling of 28 never-smoker lung cancer cases identified aberrantly expressed miRNAs, which were much fewer than in lung cancers of smokers and included miRNAs previously identified (e.g., upregulated miR-21) and unidentified (e.g., downregulated miR-138) in those smoker cases. The changes in expression of some of these miRNAs were more remarkable in cases with EGFR mutations than in those without: the most upregulated miRNA, miR-21, was more abundant in cancers with EGFR mutation. A significant correlation between phosphorylated-EGFR (p-EGFR) and miR-21 levels in lung carcinoma cell lines and the suppression of miR-21 by an EGFR-TKI, AG1478, suggested that the EGFR signaling pathway positively regulated miR-21 expression. In a never-smoker-derived lung adenocarcinoma cell line H3255 with mutant EGFR and high levels of p-EGFR and miR-21, antisense inhibition of miR-21 enhanced AG1478-induced apoptosis. In a never-smoker-derived adenocarcinoma cell line H441 with wild-type EGFR, the antisense miR-21 not only showed the additive effect with AG1478 but also induced apoptosis by itself. These results suggest that aberrantly increased expression of miR-21, which is further enhanced by the activated EGFR signaling pathway, plays a critical role in lung carcinogenesis in never-smokers and is a potential therapeutic target in both EGFR mutant and wild-type cases. Twenty-eight pairs of lung cancer tissues and corresponding noncancerous lung tissues were obtained from never-smokers who had undergone surgical resection from 2000 to 2004 at the University of Maryland Medical Center (n=15), Mayo Clinic (n=7) in United States and Hamamatsu University School of Medicine (n=6) in Japan.
Project description:To determine as a proxy transcriptional activation after induction of differentiation, we performed H3K4me3 ChIP-seq experiment of primary human keratinocytes that were treated with EGFR inhibitor AG1478 and BMP2/7 for 6 hours.
Project description:Innate pattern recognition receptors, including toll-like receptors (TLRs), can alter the tumor microenvironment and prime adaptive anti-tumor immunity. However, TLR agonists have not been well-tolerated due to toxicities associated with widespread immune activation following systemic administration. To design a therapeutic that is suitable for systemic delivery and capable of eliciting a tumor-targeted response, we developed a novel class of immune-stimulating antibody conjugates (ISACs) comprising a TLR7/8 agonist conjugated to tumor-targeting antibodies. Systemically administered anti-HER2 ISACs were well-tolerated in vivo and elicited robust activation of intratumoral myeloid cells, resulting in tumor clearance and subsequent immunological memory. In vitro potency and in vivo efficacy required tandem activity driven by intact Fc functionality and TLR agonism to enable phagocytosis and T cell-mediated anti-tumor immunity. ISAC-mediated immunological memory was not limited to HER2, as ISAC-treated mice were protected from rechallenge with a HER2-negative tumor. These results provide strong rationale for the clinical development of ISACs and show that synergy between FcgR and TLR7/8 signaling contributes to the mechanism of ISAC-mediated anti-tumor immunity.