Radioterapia metabólica com Iodo-131 associada à modulação in vitro da Expressão Gênica e de miRNAs envolvidos na Angiogênese em Colangiocarcinoma

Abstract

Introduction - Cholangiocarcinoma (CCA), the second most common hepatic neoplasm, is classified into intrahepatic (iCCA), perihilar (pCCA), and distal (dCCA). Considering the high heterogeneity of CCA, genomic and molecular characterization has expanded therapeutic actions. Radiotherapy with iodine-131 (131I), widely used in thyroid tumors, has potential application in liver neoplasms. Objectives To evaluate the effects of radiotherapy with 131I on gene expression of vascular endothelial growth factor (VEGFA) and hypoxia-inducible factor (HIF1A) as well as target miRNAs (101-3p, 126-3p, 145- 3p, 142-3p, 210-5p and 224-3p) in intrahepatic (HuCCT-1) and extrahepatic (TFK-1) CCA cell lines. Material and Methods - Human CCA cell lines (TFK-1 and HuCCT-1) and non-malignant intrahepatic cholangiocyte cell line (H69) were cultured. TFK-1 and HuCCT-1 were irradiated with 131I (doses: 1, 20, and 60Gy) at different exposure times (2 hours, 48 hours, and 12 days). After exposure, RNA and miRNA extraction was performed, for expression analyzes by RT-PCR, with results expressed as relative expression unit on a log2 fold change basis. Results In all dosages and periods, HIF1A underexpression was observed, with emphasis on doses of 1Gy after 48 hours (-0.97), followed by 20Gy (-0.60) in the HuCCT-1 cell line. The TFK-1 cell line showed reduced HIF1A values at the 60Gy dose after 2 hours (-4.0), followed by 20Gy (-3.86) and 1Gy (- 2.67) after 48 hours. There was also underexpression in all doses and periods for VEGFA in the HuCCT-1 cell line, notably at 1Gy (-0.82 48 hours) and 60Gy (-2.06 12 days). For the TFK-1 cell line, there was VEGFA underexpression for 20Gy after 12 days (- 2.09), followed by 48 hours (-0.92), and for 60Gy after 2 hours (-1.32). Regarding miRNAs, in the HuCCT-1 cell line, underexpression of miRNA-224-3p and miRNA-101- 3p was highlighted in all doses and periods, particularly for 60Gy (-1.69) after 2 hours and 12 days (-8.34), respectively; the same occurred for the oncomiR 210-5p, with emphasis on 20Gy after 48 hours (-1.12). On the other hand, other tumor-suppressor miRNAs showed elevated values in 126-3p (60Gy: 2.65), 142-3p (1Gy: 6.94), and 145- 3p (20Gy: 7.38) after 2 hours and 48 hours for the others, respectively. The TFK-1 cell line showed negative values in all doses and periods only for miRNA-126-3p, particularly for 1Gy and 60Gy after 2 hours (-8.97; -8.38, respectively). Conversely, other tumorsuppressor miRNAs showed increased values mainly after 48 hours (101-3p - 1Gy: 4.87), 2 hours (142-3p - 20Gy: 1.21), and 12 days (145-3p - 1Gy: 2.26; and 224-3p 20Gy: 2.78). The oncomiR-210-5p showed a reduction, particularly for 60Gy after 12 days (- 0.57), but overexpression after 48 hours at the 1Gy dose (2.51). Conclusion - The potential of Radiotherapy with 131I in modulating the expression of VEGFA and HIF1A genes and miRNAs is emphasized, depending on the dose and exposure time, contributing to the understanding of molecular mechanisms involved in angiogenesis, highlighting the relevance of this therapeutic modality for CCA.