RESUMEN
BACKGROUND: Breast cancer is one of the most common types among women. Its incidence progressively increases with age, especially after age 50. Platinum compounds are not efficient in the treatment of breast cancer, highlighting the use of other metals for the development of new chemotherapeutic agents. OBJECTIVE: This paper aims to obtain three new ruthenium compounds that incorporate sulfur amino acids in their structures and to investigate their cytotoxic activity in breast tumor cell lines. METHODS: Complexes with general formula [Ru(AA)(dppb)(bipy)] (complexes 1 and 2) or [Ru(AA)(dppb) (bipy)]PF6 (complex 3), where AA = L-cysteinate (1), D-penicillaminate (2), and L-deoxyalliinate (3), dppb = 1,4-bis(diphenylphosphino)butane and 2,2´-bipyridine, were obtained from the cis-[RuCl2(dppb)(bipy)] precursor. The cytotoxicity of the complexes on MDA-MB-231 (triple negative human breast cancer); MCF-7 (double positive human breast cancer) and V79 (hamster lung fibroblast) was performed by the MTT (4,5- dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide) method. The control agent was the cisplatin, which is a commercially available drug for cancer treatment. RESULTS: In complexes (1) and (2), the ligands are coordinated to the metal center by nitrogen and sulfur atoms, while in complex (3), coordination is through the oxygen and nitrogen atoms. These suggestions are based on the infrared and 31P{1H} NMR data. For complexes (1) and (2), their X-ray structures were determined confirming this suggestion. The three complexes are stable in a mixture of DMSO (80%) and biological medium (20%) for at least 48h and presented cytotoxicity against the MDA-MB-231 and MCF-7 tumor cells with reasonable selectivity indexes. CONCLUSION: Our work demonstrated that ruthenium complexes containing sulfur amino acids, bipyridines and bisphosphines showed cytotoxicity against the MDA-MB-231 and MCF-7 cancer cell lines, in vitro, and that they interact weakly with the DNA (Deoxyribonucleic Acid) and the HSA (Human Serum Albumin) biomolecules.
Asunto(s)
Aminoácidos/farmacología , Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Complejos de Coordinación/farmacología , Rutenio/farmacología , Azufre/farmacología , Aminoácidos/química , Antineoplásicos/síntesis química , Antineoplásicos/química , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , ADN/química , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Rutenio/química , Albúmina Sérica Humana/química , Relación Estructura-Actividad , Azufre/químicaRESUMEN
BACKGROUND: This study examines the association between optimistic perceptions about AIDS and unprotected sex among men who have sex with men (MSM) in the city of São Paulo, Brazil. METHODS: A cross-sectional study was carried out among MSM in leisure areas of São Paulo in 2003. We interviewed 161 participants aged 18-30 years. RESULTS: Thirty-nine per cent (95% confidence interval 32-47%) reported unprotected anal sex with steady or casual partners in the previous 6 months. The optimistic perception score created for this study was associated with unprotected sex (P = 0.01) and higher education (P = 0.02). The quartile with the most optimistic perception was 1.8 times more likely to engage in unprotected anal sex compared with the quartile with the least optimistic perception. CONCLUSION: This study suggests that the current situation regarding AIDS, which is seemingly favourable, may create optimistic perceptions leading to unprotected sexual practices. Prevention programmes, particularly for MSM, need to take this into account.