Metalloprotease-mediated cleavage of antibody–drug conjugates (ADC) targets as a novel mechanism of resistance in breast cancer

Metalloprotease-mediated cleavage of antibody–drug conjugates (ADC) targets as a novel mechanism of resistance in breast cancer.

Localisation: Cancer Research Center of Marseille (CRCM)

Supervisors: Alexandre de Nonneville and Rania Ghossoub

Objectives: Antibody–drug conjugates (ADCs) are an emerging class of therapies that have dramatically improved the therapeutic arsenal in breast cancer and other cancer types. ADCs consist of monoclonal antibodies targeting tumor-specific antigens linked to chemotherapy that powerfully kill cancer cells. To date, 12 ADCs are approved by the FDA, and three are marketed in BC: two anti-HER2 and one anti-TROP2. However, as with other types of treatments, resistance is inevitable, with only a fewmechanisms beginning to be reported (1,2), including by our laboratory (3,4). In this project, our objective is to increase our understanding of the biology underlying mechanisms of resistance to ADCs, including ADC-target extracellular domain cleavage by metalloproteases, to propose potential strategies for overcoming resistance and improving the clinical activity of ADCs.

Originality: The ADAM metalloproteases are known for their role in the cleavage of the extracellular domain of transmembrane proteins. Several studies demonstrated that Her2, Trop2, and Nectin4 are cleaved by ADAM10. Interestingly, high ADAM10 expression is associated with poor response to Trastuzumab (5,6), and ADAM10 inhibition increases response to Trastuzumab in preclinicalmodels of breast cancer (5). Consequently, we hypothesize that ADAM10 cleaves the extracellular domain of ADC targets (HER2, Trop2, Nectin4), decreasing the potential antibody fixation sites, which act in turn as decoy receptors, thereby decreasing the ability of ADCs to recognize tumor cells.

Methodology: We selected BC pre-clinical models expressing ADAM10, including triple negative BC model MDA-MB-468 sensitive to Nectin4-ADC, and the HER2+ BC model SKBR3 (sensitive to HER2-ADC). ADAM10 expression will be modulated in these cells using both genetic (siRNA & CRISPR-cas9 technology, routinely used in the lab) and pharmacological (GI254023X & INCB7839 drugs) approaches. Both parental and KD/KO cells will be treated with (several doses and serial dilutions) Nectin4-ADC or HER2-ADC and the impact of these treatments on cell growth and cytotoxicity will be evaluated using CellTiterGlo and BrdU assays. We will also evaluate the levels of HER2 cleavage in BC
patients (HER2+ or HER2-low) by immunohistochemistry analysis. In parallel, we will test for the presence of soluble “cleaved fractions” of HER2 or Nectin4 in the blood samples of the same patients by ELISA assay.Expected results. We expect to define the role of metalloproteases in ADC resistance. We will be able to gauge the mechanisms involved, whether it be a reduction in the number of Ab binding sites on the cell surface, or the role of the soluble forms of the extracellular target acting as a decoy for the ADC.

References:

1. Coates, et al. Cancer Discov. 2021.
2. Mosele, et al. Ann. of Oncol. 2022.
3. Cabaud, et al. Mol Cancer Ther. 2022.
4. De Rauglaudre, et al. Mol Cancer Ther. 2022.
5. Feldinger, et al. Oncotarget. 2014.
6. Cheng, et al. Cancer Cell Int. 2021.

Applications:

Please send CV, covering letter, notes and contact details for a referee to Alexandre de Nonneville (denonnevillea@ipc.unicancer.fr) and Rania Ghossoub (rania.ghossoub@inserm.fr)