Background: To evaluate the inhibition effect of immunoconjugate of doxorubicin(DXR) with a monoclonal antibody, 5F11 on human lung cancer cells and its reversal effect on resistant lung cancer cells to chemotherapeutic drug.
Methods: DXR was attached to 5F11 using dilute glutaraldehyde crossing.The antitumor activity of immunoconjugate, 5F11-DXR, against the sensitive antigen-positive cell line, A2, drug-resistant antigen-positive cell lines, 801-D and 801-DDXR, and antigen-negative cell line, ascite cancer cell was evaluated by human tumor cell cloning assay and dye exclusion assay.
Results: According to the results of various assays, comparing with single DXR, 5F11-DXR could significantly increase the cytotoxicity to A2, 801-D and 801-DDXR cell lines with a DXR concentration of 0.4 μg/ml(P<0.05), and this difference was even more distinct to A2 cell line with lower concentration of DXR (0.04 μg/ml). However, there was no remarkable difference between 5F11-DXR and single DXR in cytotoxicity to antigen-negative ascite cancer cell(P>0.05).
Conclusions: 5F11-DXR can remarkably increase the cytotoxicity of DXR to the sensitive target cells and even effectively reverse the drug-resistant cell lines to DXR. There is no significant difference between 5F11-DXR and DXR in killing antigen-negative cancer cells.