A conditioned medium from a human liposarcoma-derived cell line induces p53-dependent apoptosis in several tumor cell lines

A novel cell line, named LSA, has been obtained, stabilized, and characteri zed from a human liposarcoma. These cells have morphological and biochemica l features strongly resembling the adipocytes and were able to grow in the Ham's F12 medium, in presence or absence of FCS. A conditioned medium (LSA- CM) was obtained by growing the LSA cells in the F12 medium in the absence of FCS. LSA-CM had cytostatic and cytotoxic effects (apoptosis and necrosis ) associated with down-regulation of c-myc and upregulation of p53 in sever al human cell lines (breast, lung, glioblastoma, etc.). The MCF-7 and gliob lastoma cells were killed by LSA-CM in 5-6 days, whereas the same cells wer e killed by LSA-CM co incubated with low doses of cisplatin in 30 h. LSA-CM peri-tumoral injections for 15 days in Balb-c-fc3H mice affected by mammar y tumors, resulted in the rapid disruption of tumors and absence of metasta ses. In contrast, in the untreated animals the tumor masses were 4 times la rger than initial lesions, and numerous metastases were found in the lungs. The toxicity analysis of LSA-CM, performed on three different animal speci es, showed that LSA-CM is absolutely free of acute, subacute, and subcronic toxicity. The possible use of LSA-CM/cisplatin for cancer treatment is dis cussed.