Objective: This study inquired into the mechanism of cancer vascular metastasis.
Methods: The immunohistochemical method was adopted in determining the expression of intercellular adhesion molecule-1 (ICAM-1) and nuclear factor kappa B (NF kappa Bp65) on the peritumoral rectum tissues and metastatic lymph nodes of 8 patients and on the rectum tissues and lymph nodes of 5 normal human subjects. Also, the method of in situ hybridization was employed in detecting the binding site of NF kappa Bp65 on vascular endothelial cells.
Results: It was found that the proteins of ICAM-1 and NF kappa Bp65 were expressed on the vascular endothelial cells of the rectum adenocarcinoma patients, and there was a NF kappa B binding consensus sequences on ICAM-1 promoter in the vascular endothelial cells of the rectum adenocarcinoma patients. When DIG-AKP labeled 38-bp oligonucleotide probe was used, there was no expression of ICAM-1 and NF kappa Bp65 on the vascular endothelial cells of the normal human lymph node and rectum tissues.
Conclusion: The above data suggest that the activation of ICAM-1 promoter may critically depend on NF kappa Bp65 homodimers or heterodimers binding to a variant kappa B site on the vascular endothelial cells of human rectum adenocarcinoma. These may indicate the potential roles of NF kappa B in cancer metastasis, thus giving clues to the development of a novel anti-metastasis strategy.