Antitumor effect of nicotinamide combined with cisplatin in the treatment of intestinal cancer in an experimental zebrafish model

• Grant number: 23/04025-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2024
• End date: March 31, 2027
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Niels Olsen Saraiva Câmara
• Grantee: Luis Felipe Serra Moreira
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 17/05264-7 - Cell metabolism, microbiota and immune system: new paradigms in renal diseases physiopathology, AP.TEM

Abstract

Cisplatin is one of the main chemotherapeutic agents used in the treatment of various types of cancer, however, tumor cells may show resistance to the action of cisplatin and its use is associated with several adverse effects. To reduce resistance to cisplatin and its adverse effects, substances can be administered in association with chemotherapy. It is known that alkaloids such as caffeine and phenolic compounds demonstrate an anticancer effect and potential to increase the sensitivity of tumor cells against chemotherapeutic agents, in addition to reducing the damage caused by oxidative stress, through the inhibition of free radicals. There are several products that can be studied as adjuvants in chemotherapy treatment with cisplatin, such as guarana. Guarana powder has a high content of alkaloids and phenolic compounds, showing potential to reduce tumor growth and induce apoptosis and has a potent antioxidant effect, demonstrating potential to be associated with cisplatin in the treatment of intestinal cancer. Our hypothesis is that the association of guarana powder with cisplatin will be able to decrease the resistance of tumor cells, potentiate their anticancer immune effects, with increased induction of apoptosis through the regulation of the p53 protein and the Bax/Bcl-2 and reduction of PD-L1 expression, resulting in an increase in the immune response, in addition to reduce the growth of cancer cells by inhibiting the AKR/mTOR pathways. Furthermore, decrease the adverse effects of cisplatin by inhibiting free radicals through the donation of the hydrogen atom. To confirm our hypothesis, we will initially carry out an in vitro experiment administering different concentrations of guarana, cisplatin and guarana + cisplatin association in HT-29 cells, later, the in vivo experiment will be carried out by xenotransplanting HT-29 into zebrafish and submitting them to different concentrations of guarana, cisplatin and guarana + cisplatin association. A cancer induction experiment will also be carried out, administering dextran sulfate sodium and azoxymethane in zebrafish, together with doses of guarana. The HT-29 cells will have their growth evaluated through the growth curve test in the in vitro experiment, for the in vitro and in vivo experiment, the HT-29 cells will have their cell death evaluated with the Annexin V-FITC apoptosis detection kit /PI, ROS production and mitochondrial membrane potential through DFCH-DA, MitoSOX and TMRM assays. The HT-29 cells from the in vitro and in vivo experiment will have mitochondrial respiration evaluated using the Seahorse assay. Immunohistochemical analysis of HT-29 cells xenotransplanted in zebrafish will be performed. Tumor cells acquired in the three experiments will have the gene expression of cytokines evaluated through the qPCR assay. Gut histopathology, ROS determination and liver enzyme analysis will be performed for zebrafish from xenotransplantation and cancer induction experiments. The study of the antitumor immune response will be performed using macrophage and TNF reporter animals, flow cytometry and genetic analysis. Understanding the effects of the association of substances with chemotherapy drugs in the treatment against cancer will enable the emergence of new therapeutic protocols, with better results and fewer adverse effects.