Coupling tumor necrosis factor-alpha with alphaV integrin ligands improves its antineoplastic activity

Area of Science:

• Oncology
• Molecular Biology
• Biotechnology

Background:

• Tumor necrosis factor-alpha (TNF) exhibits potent anticancer effects in preclinical models but is limited in clinical use due to severe toxicity.
• Previous research demonstrated improved TNF therapeutic index by targeting aminopeptidase N (CD13), a marker on angiogenic vessels.

Purpose of the Study:

• To investigate the potential of targeting other tumor blood vessel markers using TNF conjugates.
• To evaluate the efficacy of a novel TNF-peptide conjugate targeting alpha(V) integrins in combination with melphalan for cancer treatment.

Main Methods:

• Recombinant DNA technology was used to fuse TNF with the ACDCRGDCFCG peptide, a known ligand for alpha(V) integrins.
• Antitumor effects were assessed in tumor-bearing mice treated with the conjugate and melphalan.
• Cell adhesion assays, competitive binding experiments with anti-integrin antibodies, and cytolytic assays were performed to confirm binding and cytotoxic activity.

Main Results:

• Subnanogram doses of the ACDCRGDCFCG-TNF conjugate combined with melphalan induced significant antitumor effects in mice.
• The Arg-Gly-Asp moiety of the peptide demonstrated interaction with alpha(V)beta(3) integrin and other cell adhesion receptors.
• The conjugate exhibited direct cytotoxic effects, indicating functional TNF receptor binding and induction of cell death signals.

Conclusions:

• Coupling TNF with alpha(V) integrin ligands enhances its antineoplastic activity and improves its therapeutic index.
• Vascular targeting of tumor vasculature using ligands like ACDCRGDCFCG represents a viable strategy for improving TNF-based cancer therapies.
• This approach is potentially applicable to various endothelial markers beyond CD13 for broader therapeutic applications.