Avaliação do potencial antitumoral de derivados de pirazolinas para o tratamento do câncer de bexiga

Abstract

Bladder cancer is the 9th most common malignancy in the world. Approximately 75% of bladder cancer are non-muscle invasive, which has a low rate of progression but a high risk of recurrence. The remaining 25% are muscle invasive and present less favorable prognosis with high risk of metastasis. Current chemotherapy is often limited mainly due to toxicity and development of drug resistance. Therefore, there is a continued commitment to discover new anticancer agents. Pyrazolines are dihydro pyrazoles, which contain two adjacente nitrogen atoms in their five membered ring. Many recent studies have shown that pyrazolines are promising antitumor agent in many types of cancer, however, there are no reports in bladder cancer. In the presente study, was evaluated the antitumor potenctial of pyrazoline derivatives in bladder cancer cell lines. The determination of citotocixity of the compounds was performed using MTT assay, the compounds 1-thiocarbamoyl-3,5-diphenyl-4,5-dihydro-1H-pyrazole (2a) and 1-thiocarbamoyl-5-(4-chlorophenyl)-3-phenyl-4,5-dihydro-1H-pyrazole (2c) which had the best cytotoxic activity in this assay, in 5637 cells, were subjected to other biological assays. Molecular modeling studies were performed to predict oral bioavailability and toxicity of the compounds. Clonogenic assay and flow cytometric analysis were used to acess colony formation, apoptosis induction and cell cycle distribution in 5637 cell line. Ultimately, the effect of combining derivaties 2a and 2c with gemcitabine was also evaluated. Our results demonstrated that the compounds containing the substituents hydrogen (2a) and chlorine (2c) showed the best antitumor activity in 5637 (IC50 69.14 e 66.94 μM, respectivaly). Molecular modeling studies indicated that pyrazoline derivatives 2a-d had an apropriate criteria to oral bioavailability and low toxicity. Compounds 2a and 2c significantly decreased colony formation. Furthemore, pyrazoline 2a induced apoptosis and arrest cell cycle in G2/M phase while pyrazoline 2c disrupts the cell cycle in G0/G1 phase. The effect of combining derivatives 2a and 2c with gemcitabine was synergistic. Moreover, the combination with pyrazoline 2a demonstrated a significant increase in inhibition of cell growth when compared to individual treatments. Therefore, pyrazoline derivatives 2a and 2c may have potential for future clinical application in the treatment of bladder cancer.