[Participation of ICAM-1 in the cytotoxicity of TM-TNF-alpha mediated by TNF receptor I].

Aim: To identify membrane-associated molecules involved in the tumoricidal cytotoxicity of TM-TNF-alpha and to explore the molecular mechanism underlying the tumoricidal cytotoxicity of TM-TNF-alpha and differences of biological effects between TM-TNF-alpha and sTNF.

Methods: Antibody blocking test and RT-PCR were used to evaluate the role of ICAM-1 and VCAM-1 in the cytotoxicity of TM-TNF-alpha mediated by TNFR I or TNFR II.

Results: After the ICAM-1 expressed on the membrane of MCF-7 cells(expressing TNFRI) was blocked, the cytotoxicity of TM-TNF-alpha to this cell lines decreased significantly, while blocking VCAM-1 had no effect. Blocking ICAM-1 or VCAM-1 expressed on the membrane of HL-60 cells(expressing TNFRII)had no significant effects on the cytotoxicity of TM-TNF-alpha to this cell lines.

Conclusion: ICAM-1 participates in the cytotoxicity of TM-TNF mediated by TNFRI.