title: A search for multidrug resistance modulators: the effects of retinoids in human colon carcinoma cells.
abstract: The development of multidrug resistance (MDR) is one of the major causes of failure in cancer therapy. The use of cell lines with acquired resistance to anticancer agents represents a very good tool for investigation into the possibility of reversal of MDR. In this study the ability of all-trans-retinoic acid (RA) and its derivative 6-OH-11-O-hydroxyphenanthrene (IIF; pat. WIPO W000 /117143) as antitumor agents was investigated in the human colon carcinoma cell line LoVo and in the counterpart resistant derivative LoVo/MDR cell line. Cell proliferation was measured by MTT assay, apoptosis was evaluated using DNA fragmentation and Annexin V detection assay. Retinoids suppressed cell proliferation in a time- and dose-dependent manner. Interestingly, IIF was significantly more effective than RA, particularly on LoVo/MDR cells. RA and IIF induced apoptosis in both cell lines, with IIF effect significantly higher than that of RA. Furthermore, on the basis that MDR phenotype is often caused by drug efflux due to overexpression of the membrane P-glycoprotein (P-gp), it was demonstrated that RA and IIF reduced P-gp synthesis in LoVo/MDR cells. Our results suggest that IIF could be a powerful tool in the development of colon carcinoma treatments, even when tumor cells present an MDR phenotype.
authors.affiliation: Department of Experimental Evolutive Biology, University of Bologna, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Bartolini
authors.forename: M
authors.initials: M
authors.lastname: Orlandi
authors.forename: A
authors.initials: A
authors.lastname: Papi
authors.forename: K
authors.initials: K
authors.lastname: Ammar
authors.forename: F
authors.initials: F
authors.lastname: Guerra
authors.forename: A M
authors.initials: AM
authors.lastname: Ferreri
authors.forename: P
authors.initials: P
authors.lastname: Rocchi
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000230:Adenocarcinoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D018432:Drug Resistance, Multiple / Q000187:drug effects*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D005562:Formazans / Q000378:metabolism; D006801:Humans; D013778:Tetrazolium Salts / Q000378:metabolism; D014212:Tretinoin / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D005562:Formazans; C475805:IIF compound; D013778:Tetrazolium Salts; C079782:MTT formazan; D014212:Tretinoin