Targeted anti-tumor agents and their cytotoxicity on gastric cancer cells in vitro

Area of Science:

• Oncology
• Immunology
• Pharmacology

Background:

• Monoclonal antibodies offer targeted delivery for cancer therapeutics.
• Chemotherapeutic drugs and toxins can be conjugated to antibodies to enhance selectivity.
• Developing targeted drug delivery systems is crucial for improving cancer treatment efficacy.

Purpose of the Study:

• To conjugate chemotherapeutic drugs and toxins with specific monoclonal antibodies.
• To evaluate the antigen-binding capacity of the antibody conjugates.
• To assess the selective cytotoxic effects of these conjugates on target cancer cells.

Main Methods:

• Conjugation of methotrexate, daunomycin, mitomycin C, ricin, and ricin A chain to murine monoclonal antibodies MGb2 and MG11.
• Direct linkage or linkage via human serum albumin as an intermediary.
• Enzyme-Linked Immunosorbent Assay (ELISA) to assess antigen-binding capacity.
• Chronic cytotoxicity assays on human gastric cancer cells (KATOIII) and non-target cells.

Main Results:

• Antibody-drug conjugates retained antigen-binding capacity after conjugation.
• Conjugates exhibited highly selective cytotoxic effects on target cells.
• Cytotoxicity on KATOIII cells was comparable to free drugs/ricin but superior to irrelevant conjugates.
• Minimal effect observed on non-target cells, indicating antibody-mediated targeting.

Conclusions:

• Monoclonal antibody-drug conjugates can be effectively prepared while maintaining antibody function.
• These conjugates demonstrate significant selective cytotoxicity against target cancer cells.
• The selective targeting of cancer cells by these conjugates is mediated by the monoclonal antibodies.