[Effects of lanthanum and cerium on malignant proliferation and expression of tumor-related gene].

Cultured human gastric cancer cell line PAMC82 was studied in vitro to further verify anti-tumor effect sof rare-earth elements and explore their mechanism of tumor inhibition. Inhibitory effects of elements lanthanum and cerium on cell growth, reverse effects of them on reduction of malignancy and effects of them on level of expression of oncogene and cancer suppressor gene were observed. Lanthanum chloride, cerium chloride and mixed rare-earth chloride at levels of 0.5 to 1.5 mmol/L could inhibit obviously growth of cancer cells and change cell morphology and microtubule structure of PAMC82, similar to that of normal cells, their colony-forming ability lowered in soft agar, and expression of tumor suppressor gene p53, p16 and p21 increased and that of gene nm23 lowered.