Combinatorial effects of monoclonal anti-p120 antibody (MAbp120), liposomes and hyperthermia on MCF-7 and LOX tumor cell lines.

The human nucleolar protein p120 is highly expressed in human cancers. Its high expression in breast cancer correlates with a poor prognosis, and its overexpression in 3T3 mouse fibroblasts causes malignant transformation. This study reports that a combination of monoclonal anti-p 120 antibody (MAbp120), liposomes (Lipo), and hyperthermia (HT) resulted in enhanced antitumor effects in cultured human breast adenocarcinoma (MCF-7) and human amelanotic melanoma (LOX) cells. Monoclonal antibody uptake and intracellular localization of the protein p120 were monitored by double labeling indirect immunofluorescence. Cell growth inhibition by the combination of MAbp120 + Lipo + HT was 65% for MCF-7 cells and 96% for LOX cells. When tested on LOX cells, monoclonal antibodies (MAbB23, MAbC23) to other nucleolar proteins (B23, C23) produced only slight cytotoxicity with similar treatment protocols.