Monoclonal antibody G250 targeting CA Ⅸ: Binding specificity, internalization and therapeutic effects in a non‑renal cancer model

  • Authors:
    • Miriam Zatovicova
    • Lenka Jelenska
    • Alzbeta Hulikova
    • Peter Ditte
    • Zuzana  Ditte
    • Lucia Csaderova
    • Eliska Svastova
    • Wolfgang Schmalix
    • Volker  Boettger
    • Paul Bevan
    • Jaromir Pastorek
    • Silvia Pastorekova
  • View Affiliations

  • Published online on: September 17, 2014     https://doi.org/10.3892/ijo.2014.2658
  • Pages: 2455-2467
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Abstract

G250 (Girentuximab) is a chimeric IgG1 monoclonal antibody (MAb) currently being evaluated as an immunotherapy for kidney cancer. It targets carbonic anhydrase protein (CA Ⅸ), a transmembrane carbonic anhydrase (CA) isoform, which is regulated by VHL/HIF pathway and hence expressed in the majority of renal cell carcinomas (RCCs) as well as in hypoxic non‑RCC tumours. CA Ⅸ functions in pH regulation and cell migration/invasion, and supports tumour cell survival in hypoxia and/or acidosis. It contains a highly active extracellular catalytic domain (CA) extended N‑terminally with a proteoglycan‑like region and C‑terminally with short transmembrane and intracellular regions. Here we characterize the binding and internalization properties of G250, as well as its therapeutic effects in animal model, and discuss the impact of G250‑mediated immunotherapy in non‑RCC tumours. We demonstrated that G250 MAb recognizes a conformational epitope in the CA domain, detects the soluble CA Ⅸ ectodomain (ECD), but not the splicing variant, and does not cross‑react with CA Ⅰ, Ⅱ, and Ⅻ isoforms. We showed that G250 internalizes via clathrin‑coated vesicles, escapes degradation in lysosomes and enters the recycling pathway via the perinuclear compartment. This results in long intracellular persistence and enables consecutive internalization cycles. Moreover, the recycled antibody maintains an intact Fc portion potentially capable of continuous induction of antibody‑dependent cell‑mediated cytotoxicity (ADCC) response, thus explaining its therapeutic efficacy. Finally, we showed that G250 treatment is effective against HT‑29 colorectal carcinoma xenografts that differ from RCC by more heterogeneous, hypoxia‑related expression of CA Ⅸ. These results suggest potential therapeutic usefulness of the G250 MAb in non‑RCC tumours.
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December-2014
Volume 45 Issue 6

Print ISSN: 1019-6439
Online ISSN:1791-2423

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Spandidos Publications style
Zatovicova M, Jelenska L, Hulikova A, Ditte P, Ditte Z, Csaderova L, Svastova E, Schmalix W, Boettger V, Bevan P, Bevan P, et al: Monoclonal antibody G250 targeting CA Ⅸ: Binding specificity, internalization and therapeutic effects in a non‑renal cancer model. Int J Oncol 45: 2455-2467, 2014
APA
Zatovicova, M., Jelenska, L., Hulikova, A., Ditte, P., Ditte, Z., Csaderova, L. ... Pastorekova, S. (2014). Monoclonal antibody G250 targeting CA Ⅸ: Binding specificity, internalization and therapeutic effects in a non‑renal cancer model. International Journal of Oncology, 45, 2455-2467. https://doi.org/10.3892/ijo.2014.2658
MLA
Zatovicova, M., Jelenska, L., Hulikova, A., Ditte, P., Ditte, Z., Csaderova, L., Svastova, E., Schmalix, W., Boettger, V., Bevan, P., Pastorek, J., Pastorekova, S."Monoclonal antibody G250 targeting CA Ⅸ: Binding specificity, internalization and therapeutic effects in a non‑renal cancer model". International Journal of Oncology 45.6 (2014): 2455-2467.
Chicago
Zatovicova, M., Jelenska, L., Hulikova, A., Ditte, P., Ditte, Z., Csaderova, L., Svastova, E., Schmalix, W., Boettger, V., Bevan, P., Pastorek, J., Pastorekova, S."Monoclonal antibody G250 targeting CA Ⅸ: Binding specificity, internalization and therapeutic effects in a non‑renal cancer model". International Journal of Oncology 45, no. 6 (2014): 2455-2467. https://doi.org/10.3892/ijo.2014.2658