Abstract 3041: Co-administration of iRGD and therapeutic EGFR-antibodies Cetuximab and Panitumumab enhances drug penetration in NSCLC PDX based 3D multicellular spheroids
Authors: Lashuk Kanstantsin , Klett Hagen , Kolica Agon , Göttlich Claudia , Schüler Julia 
Published: September 2020

Abstract
Three-dimensional (3D) cell culture platforms are increasingly being used in cancer research and drug development. Using patient derived xenograft (PDX) as tumor cell source the clinical relevance of those platforms increases significantly. In combination with live cell imaging capabilities a powerful tool for dynamic studies of drug-cell interactions arises. In the current study we determined the penetration of anti-EGFR antibodies cetuximab and panitumumab in NSCLC spheroids in different culture conditions (w/wo human dermal fibroblasts, HDF) and in combination with the permeabilization-enhancing peptide iRGD. Six different NSCLC PDX models were selected based on their EGFR protein expression level (ranging from high to low determined by immunohistochemistry on PDX tissue). Cetuximab and panitumumab, were labelled with an Alexa-Fluor488 dye and their real-time uptake kinetics were quantified in an IncuCyte S3 device (1 image/well/h, Sartorius). Apart from the absolute fluorescence within the spheroid, we developed a mathematical description, fitting intensity levels in separate regions of the spheroids to estimate spatial dependent penetration of the compound in a time-resolved manner. The accumulation of EGFR antibodies over time was positively correlated with the target expression on the corresponding PDX. In addition, the invasion of the antibodies was significantly influenced by the compactness of the spheroids. The compactness of the tumor spheroid was model immanent and dependent on the molecular make-up of the respective tumor line. Enhancing the compactness by adding HDF to the tumor spheroid reduced the infiltration of both tested antibodies markedly. The simultaneous treatment of anti-EGFR antibodies with iRGD enhanced the penetration capacity in a dose dependent manner. The data of the current study highlight the importance of the tumor microenvironment (TME) for the sensitivity of tumor cells towards anticancer treatment. The modulation of the TME will be an important approach to increase antitumoral activity by enhancing the compound concentration in the tumor tissue. In general, this screening approach can be applied to fluorescence-labelled large molecules as well as compounds with intrinsic fluorescence characteristics. The combination of life cell imaging and image analysis is a promising tool in preclinical drug development to optimize compounds with regard to tissue penetration and binding efficiency.
Citation Format: Kanstantsin Lashuk, Hagen Klett, Agon Kolica, Claudia Göttlich, Julia Schüler. Co-administration of iRGD and therapeutic EGFR-antibodies Cetuximab and Panitumumab enhances drug penetration in NSCLC PDX based 3D multicellular spheroids [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3041.