Ovarian cancer is the leading cause of mortality resulting from gynecologic
cancer. A common anti-ovarian
tumor drug is
cisplatin; however, repeated use of
cisplatin causes severe resistance and leads to poor long-term survival rate in
ovarian cancer patients. Recently, it was reported that
lanthanum chloride (LaCl3) may inhibit
tumor growth and induce apoptosis in certain
cancer cells. In the present study, the effect of LaCl3 on
ovarian cancer was determined in vivo and in vitro. A
cisplatin-sensitive human
ovarian cancer cell line, COC1, was used in the current study. A xenograft animal model of
ovarian cancer was established injecting COC1 or
cisplatin-resistant COC1 cells (COC1/DDP) cells into mice. A TUNEL assay was used to determine the apoptosis of the COC1 or COC1/DDP cells and a immunohistochemical assay was conducted to measure the expression of B-cell lymphoma-2, Ki67,
breast cancer 1 (BRCA)1, BRCA2 and excision repair cross-complementation group 1 in COC1 or COC1/DDP cells. It was observed that LaCl3 promoted apoptosis in COC1 and COC1/DDP cells. In addition, LaCl3 plus
cisplatin led to further increase in the expression levels of tumor suppressor genes and decrease in the expression of oncogenes. Furthermore, application of LaCl3 and
cisplatin inhibited
tumor growth in vivo in a xenograft animal model. These results indicated the synergistic role of LaCl3 on
cisplatin-induced inhibition of
cancer cell proliferation and
tumor growth, providing a potential and effective candidate for the treatment of ovarian
tumors.