Biology subjects

Mock, J.

Publications and source records attributed to Mock, J..

3 recordsLinked to original sources

bioRxiv2022

A novel dimeric FAP-targeting small molecule-radio conjugate with high and prolonged tumour uptake

Imaging procedures based on small molecule-radio conjugates (SMRCs) targeting fibroblast activation protein (FAP) have recently emerged as a powerful tool for the diagnosis of a wide variety of tumours. However, the therapeutic potential of radiolabeled FAP-targeting agents is limited by their short residence time in neoplastic lesions. In this work, we present the development and in vivo characterization of BiOncoFAP, a new dimeric FAP-binding motif with extended tumour residence time and favorable tumour-to-organ ratio. MethodsThe binding properties of BiOncoFAP and its monovalent OncoFAP analogue were assayed against recombinant hFAP. Preclinical experiments with [177Lu]Lu-OncoFAP-DOTAGA (177Lu-OncoFAP) and [177Lu]Lu-BiOncoFAP-DOTAGA (177Lu-BiOncoFAP) were performed in mice bearing FAP-positive HT-1080 tumours. ResultsOncoFAP and BiOncoFAP displayed comparable sub-nanomolar dissociation constants towards hFAP in solution, but the bivalent BiOncoFAP bound more avidly to the target immobilized on solid supports. In a comparative biodistribution study, 177Lu-BiOncoFAP exhibited a more stable and prolonged tumour uptake than 177Lu-OncoFAP ([~]20% ID/g vs [~]4% ID/g, at 24h p.i., respectively). Notably, 177Lu-BiOncoFAP showed favorable tumour-to-organ ratios with low kidney uptake. Both 177Lu-OncoFAP and 177Lu-BiOncoFAP displayed potent anti-tumour efficacy when administered at therapeutic doses in tumour bearing mice. Conclusions177Lu-BiOncoFAP is a promising candidate for radioligand therapy of cancer, with favorable in vivo tumour-to-organ ratio, long tumour residence time and potent anti-cancer efficacy.

pharmacology and toxicology↗

bioRxiv2021

MK2 Expression Promotes Non-Small Cell Lung Cancer Cell Death and Predicts Survival

Non-small cell lung cancers demonstrate intrinsic resistance to cell death even in response to chemotherapy. Previous work suggested that defective nuclear translocation of active caspase 3 may play a role in resistance to cell death. Separately, our group has identified that mitogen activated protein kinase activated protein kinase 2 (MK2) is required for nuclear translocation of active caspase 3 in the execution of apoptosis. This study demonstrates a relatively low expression of MK2 in non-small cell lung carcinoma cell lines compared to small cell carcinoma cell lines. Further, overexpression of MK2 in non-small cell lung carcinoma cell lines results in increased caspase 3 activity and caspase 3 mediated cell death. Higher MK2 transcript levels were observed in patients with earlier-stage non-small cell lung cancer. Higher expression of MK2 is associated with better survival in patients with early stage non-small cell lung cancer across two independent clinical datasets. Using data sets spanning multiple cancer types, we observed improved survival with higher MK2 expression was unique to lung adenocarcinoma. Mechanistically, MK2 promotes nuclear translocation of caspase 3 leading to PARP1 cleavage and execution of cell death. While MK2 can directly phosphorylate caspase 3, neither phosphorylation status of caspase 3 nor the kinase activity of MK2 impacts caspase 3 activation, nuclear translocation and execution of cell death. Rather, a non-kinase function of MK2, specifically trafficking via its nuclear localization sequence, is required for caspase 3 mediated cell death. In summary this study highlights the importance of a non-enzymatic function of MK2 in the execution of apoptosis, which may be leveraged in the adjunctive treatment of NSCLC or other conditions where regulation of apoptosis is crucial.

cancer biology↗

bioRxiv2020

Antibody-mediated delivery of LIGHT to the tumor boosts Natural Killer cells and delays tumor progression

BackgroundLIGHT is a member of the TNF superfamily, which has been claimed to mediate anti-tumor activity on the basis of cancer cures observed in immunocompetent mice bearing transgenic LIGHT-expressing tumors. The preclinical development of a LIGHT-based therapeutic has been hindered by the lack of functional stability exhibited by this protein. MethodsHere, we describe the cloning, expression and characterization of five antibody-LIGHT fusion proteins, directed against the alternatively-spliced EDA domain of fibronectin, a conserved tumor-associated antigen. ResultsAmong the five tested formats, only the sequential fusion of the F8 antibody in single-chain diabody format, followed by the LIGHT homotrimer expressed as a single polypeptide, yielded a protein (termed "F8-LIGHT") which was not prone to aggregation. A quantitative biodistribution analysis in tumor bearing mice, using radioiodinated protein preparations, confirmed that F8-LIGHT was able to preferentially accumulate at the tumor site, with a tumor-to-blood ratio of ca. five to one twenty-four hours after intravenous administration. Tumor therapy experiments, performed in two murine tumor models (CT26 and WEHI-164), featuring different levels of lymphocyte infiltration into the neoplastic mass, revealed that F8-LiGHT could significantly reduce tumor cell growth and was more potent than a similar fusion protein (KSF-LIGHT), directed against hen egg lysozyme and serving as negative control of irrelevant specificity in the mouse. At a mechanistic level, the activity of F8-LiGHT was mainly due to an intratumoral expansion of Natural Killer cells, whereas there was no evidence of expansion of CD8+ T cells, neither in the tumor, nor in draining lymph nodes. ConclusionWe developed a novel recombinant LIGHT fusion protein, able to accumulate at the site of disease and which displayed anti-tumor activity in two mouse models of cancer.

immunology↗