title: A possible anti-proliferative and anti-metastatic effect of irradiated riboflavin in solid tumours.
abstract: Riboflavin is a potent photosensitizer as well as part of the vitamin B complex. Recently we demonstrated that the products generated by irradiation of riboflavin have potential as anti-leukaemic therapy. The possible action, however, of the riboflavin photoproducts in solid cancers has not been addressed. Hence, we investigated the effects of irradiated riboflavin on androgen-independent human prostate cancer cells (PC3), a known model for solid tumour cells with an exceptional resistance to therapy. Our results show that riboflavin photoproducts are cytotoxic to these cells in a FasL-Fas-dependent manner. Furthermore, irradiated riboflavin inhibited matrix-degrading proteases, caused downregulation of VEGF and upregulation of TIMP1 suggesting anti-metastatic potential. Together, these results show that the anti-neoplastic action of riboflavin photoproducts is not limited to haematological malignancies, warranting clinical studies in solid tumours.
authors.affiliation: Departamento de Bioquímica, Universidade Estadual de Campinas, Brazil.
authors.forename: Karla Cristiana
authors.initials: KC
authors.lastname: de Souza Queiroz
authors.forename: Willian Fernando
authors.initials: WF
authors.lastname: Zambuzzi
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Santos de Souza
authors.forename: Rodrigo Augusto
authors.initials: RA
authors.lastname: da Silva
authors.forename: Daisy
authors.initials: D
authors.lastname: Machado
authors.forename: Giselle Zenker
authors.initials: GZ
authors.lastname: Justo
authors.forename: Hernandes F
authors.initials: HF
authors.lastname: Carvalho
authors.forename: Maikel P
authors.initials: MP
authors.lastname: Peppelenbosch
authors.forename: Carmen Veríssima
authors.initials: CV
authors.lastname: Ferreira
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured / Q000187:drug effects; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008297:Male; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy* / Q000556:secondary; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011467:Prostate / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D051381:Rats; D012256:Riboflavin / Q000494:pharmacology*
chemical_list: D017319:Photosensitizing Agents; D020169:Caspases; D012256:Riboflavin