VT68.2: An Antibody to Chondroitin Sulfate Proteoglycan 4 (CSPG4) Displays Reactivity against a Tumor-Associated
Bernice Nounamo1, Fariba Jousheghany1, Eric Robb Siegel2
1Department of Pathology, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR 72205, USA.
Abstract:
The anti-CSPG4 monoclonal antibodies (mAbs) have shown anti-tumor activity and therapeutic potential for treating breast cancer. In addition, CSPG4 is a dominant tumor-associated antigen that is also involved in normal-tissue development in humans. Therefore, the potential for off-tumor activity remains a serious concern when targeting CSPG4 therapeutically. Previous work suggested that glycans contribute to the binding of specific anti-CSPG4 antibodies to tumor cells, but the specificity and importance of this contribution are unknown. In this study, the reactivity of anti-CSPG4 mAbs was characterized with a peptide mimetic of carbohydrate antigens expressed in breast cancer. ELISA, flow cytometry, and microarray assays were used to screen mAbs for their ability to bind to carbohydrate-mimicking peptides (CMPs), cancer cells, and glycans. The mAb VT68.2 displayed a distinctly strong binding to a CMP (P10s) and bound to triple-negative breast cancer cells. In addition, VT68.2 showed a higher affinity for N-linked glycans that contain terminal fucose and fucosylated lactosamines. The functional assays demonstrated that VT68.2 inhibited cancer cell migration. These results define the glycoform reactivity of an anti-CSPG4 antibody and may lead to the development of less toxic therapeutic approaches that target tumor-specific glyco-peptides.
Insights
This study characterizes anti-CSPG4 monoclonal antibodies (mAbs) for breast cancer therapy. The mAb VT68.2 targets specific glyco-peptides, inhibiting cancer cell migration and potentially reducing off-tumor toxicity.
Area of Science:
- Oncology
- Immunology
- Glycobiology
Background:
- Anti-CSPG4 monoclonal antibodies (mAbs) show therapeutic potential for breast cancer.
- CSPG4 is a tumor antigen, but its role in normal tissue development raises concerns about off-tumor activity.
- The contribution of glycans to anti-CSPG4 antibody binding specificity is not well understood.
Purpose of the Study:
- To characterize the glycoform reactivity of anti-CSPG4 mAbs.
- To investigate the binding specificity of anti-CSPG4 mAbs to carbohydrate antigens.
- To evaluate the therapeutic potential of targeting CSPG4-specific glyco-peptides.
Main Methods:
- Screening of anti-CSPG4 mAbs using ELISA, flow cytometry, and microarray assays.
- Testing mAb binding to carbohydrate-mimicking peptides (CMPs), cancer cells, and glycans.
- Functional assays to assess the impact of mAb binding on cancer cell migration.
Main Results:
- The mAb VT68.2 demonstrated strong binding to a specific CMP (P10s) and triple-negative breast cancer cells.
- VT68.2 exhibited higher affinity for N-linked glycans containing terminal fucose and fucosylated lactosamines.
- Functional assays confirmed that VT68.2 inhibited cancer cell migration.
Conclusions:
- The glycoform reactivity of the anti-CSPG4 antibody VT68.2 has been defined.
- Targeting tumor-specific glyco-peptides may lead to more effective and less toxic breast cancer therapies.
- This research paves the way for developing targeted therapies with reduced off-tumor effects.
