Comparative analysis of the DNA damage response induced by BNCT in human cell lines of different cancers

PERALTA T; ROSSICH L; NIEVAS S; PERONA M; CARPANO M,; CUROTTO P; POZZI E; THORP S; PISAREV M; JUVENAL G; DAGROSA MA

Granada

Congreso; 19TH iNTERNATIONAL CONGRESS OF NEUTRON CAPTURE THERAPY (ICNCT); 2021

Introduction: The Boron Neutron Capture Therapy (BNCT) is a two-steps procedure to treat different cancers. As first step a boron compound with very high propensity to capture neutrons is administrated to the patient. In the second step takes place the irradiation of the tumor area with thermal neutrons. The neutrons cause nuclear fission of the 10B atom resulting in the emission of 4He and 7Li nuclei and gamma radiation causing direct and indirect damage to the DNA. Due to the need to continue researching the molecular pathways involved in the response to DNA damage after BNCT, a study was carried out that hypothesized the existence of an interaction between TGF beta pathway and the ATM-initiated DNA repair pathway. The TGF-beta pathway has as its main effectors the SMAD proteins, which, depending on their type, play a tumor promoter or suppressor role (1). The antitumor role of SMAD2 is documented by forming a complex with SMAD4 to promote apoptosis and prevent tumor development (2). As well as the pro-tumor role of SMAD7 is described by two mechanisms, promoting genomic instability and inhibiting the TGF-beta pathway by acting as a regulator by negative feedback (3). Materials and Methods: Three human cell lines of colon adenocarcinoma (HT29), undifferentiated thyroid cancer (8505c) and melanoma (M8), were seeded in bottles of 25 cm2 and each one was separated in three groups: 1) BNCT (using 0.925 mM of boronophenylalanine plus neutrons), NCT (neutrons alone) and Control. The irradiation was carried out in RA-3 reactor (Neutron flux of 1.10 10 n / cm2 sec) and the total physical absorbed dose was 3 Gy. After 2 h of incubation at 37 ° C, the total RNA was extracted with Trizol and RT-qPCR was performed for each gene: TGF beta1, SMAD2 SMAD7, ATM and ATR. Results: In the HT29 cell line the comparison between the BNCT and Control groups showed a significant decrease in the expression of ATM (p