Project description:Somatostatin receptor 2 (SSTR2) is overexpressed in neuroendocrine tumors (NETs) and meningiomas. The objective of this study was to develop an SSTR2-targeted therapy to treat both tumor types. We engineered and humanized an anti-SSTR2 monoclonal antibody (mAb) demonstrating strong cancer cell binding, internalization in cancer cells, and tumor specificity, as evidenced by flow cytometry, confocal microscopy, and live-animal imaging. Antibody-drug conjugates (ADCs) were generated by conjugating the SSTR2 mAb with potent payloads, including monomethyl auristatin F (MMAF) or mertansine (DM1). In vitro assessments revealed high cytotoxicity across diverse NET subtypes and meningioma cell lines. In vivo efficacy was confirmed in two mouse models, i.e. subcutaneous NET xenografts and intracranial meningioma xenografts, where treatment inhibited proliferation, induced apoptosis and cell death, exhibited minimal toxicity, and extended survival. The mechanism of action was further elucidated through bulk RNA sequencing post-treatment. These findings highlight the therapeutic potential of our humanized SSTR2 mAb for targeted payload delivery in NETs and meningiomas.
Project description:NF1 is a tumor suppressor widely mutated across several cancers. Its best characterized function is the inhibition of RAS signaling through its GTPase-Activating Protein (GAP) domain. Additional functions have been proposed but not deeply investigated, due to its large size and complex domain structure. Here, combining patient data, in vitro/in vivo models and protein biochemistry, we show that NF1 is a novel Microtubule-Associated Protein (MAP) that modulates microtubular dynamics and intra-tubular repair. NF1 loss results in mitotic defects such as prolonged mitosis, supranumerary centrosomes and chromosome missegregation, leading to low-grade aneuploidy in cell lines and patients. Loss of NF1-mediated intratubular repair creates a liability specifically targetable by maytansinoids, a class of microtubule-depolymerizing agents widely used as payloads in Antibody-Drug Conjugates such as Trastuzumab-Emtansine (T-DM1). Our results directly imply loss of intratubular repair as a driver of tumorigenesis, and NF1 as the first ADC payload-associated biomarker.
Project description: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: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: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).