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  2. An amino acid transporter subunit as an antibody-drug conjugate target in colorectal cancer

An amino acid transporter subunit as an antibody-drug conjugate target in colorectal cancer

  • J Exp Clin Cancer Res. 2023 Aug 9;42(1):200. doi: 10.1186/s13046-023-02784-0.
Juan Carlos Montero 1 2 3 Sofía Del Carmen 4 Mar Abad 4 José M Sayagués 4 5 Antonio Barbáchano 5 6 Asunción Fernández-Barral 5 6 Alberto Muñoz 5 6 Atanasio Pandiella 7 8
Affiliations

Affiliations

  • 1 Institute of Biomedical Research of Salamanca (IBSAL), Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), Salamanca, Spain. jcmon@usal.es.
  • 2 Department of Pathology and IBSAL, University Hospital of Salamanca, Salamanca, Spain. jcmon@usal.es.
  • 3 CIBERONC, Madrid, Spain. jcmon@usal.es.
  • 4 Department of Pathology and IBSAL, University Hospital of Salamanca, Salamanca, Spain.
  • 5 CIBERONC, Madrid, Spain.
  • 6 Instituto de Investigaciones Biomédicas 'Alberto Sols', CSIC-Autonomous University of Madrid, and Instituto de Investigación Sanitaria del Hospital Universitario La Paz, Madrid, Spain.
  • 7 Institute of Biomedical Research of Salamanca (IBSAL), Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), Salamanca, Spain. atanasio@usal.es.
  • 8 CIBERONC, Madrid, Spain. atanasio@usal.es.
Abstract

Background: Advanced colorectal Cancer (CRC) is difficult to treat. For that reason, the development of novel therapeutics is necessary. Here we describe a potentially actionable plasma membrane target, the amino acid transporter protein subunit CD98hc.

Methods: Western blot and immunohistochemical analyses of CD98hc protein expression were carried out on paired normal and tumoral tissues from patients with CRC. Immunofluorescence and western studies were used to characterize the action of a DM1-based CD98hc-directed antibody-drug conjugate (ADC). MTT and Annexin V studies were performed to evaluate the effect of the anti-CD98hc-ADC on cell proliferation and Apoptosis. CRISPR/Cas9 and shRNA were used to explore the specificity of the ADC. In vitro analyses of the antitumoral activity of the anti-CD98hc-ADC on 3D patient-derived normal as well as tumoral organoids were also carried out. Xenografted CRC cells and a PDX were used to analyze the antitumoral properties of the anti-CD98hc-ADC.

Results: Genomic as well proteomic analyses of paired normal and tumoral samples showed that CD98hc expression was significantly higher in tumoral tissues as compared to levels of CD98hc present in the normal colonic tissue. In human CRC cell lines, an ADC that recognized the CD98hc ectodomain, reached the lysosomes and exerted potent antitumoral activity. The specificity of the CD98hc-directed ADC was demonstrated using CRC cells in which CD98hc was decreased by shRNA or deleted using CRISPR/Cas9. Studies in patient-derived organoids verified the antitumoral action of the anti-CD98hc-ADC, which largely spared normal tissue-derived colon organoids. In vivo studies using xenografted CRC cells or patient-derived xenografts confirmed the antitumoral activity of the anti-CD98hc-ADC.

Conclusions: The studies herewith reported indicate that CD98hc may represent a novel ADC target that, upon well-designed clinical trials, could be used to increase the therapeutic armamentarium against CRC.

Keywords

Antibody–drug conjugates; CD98hc; Colorectal cancer; Targeted therapy.

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