Circulating miR-21 as a prognostic biomarker in HCC treated by CT-guided high-dose rate brachytherapy.

BACKGROUND AND AIMS: Prognostic biomarkers identifying patients with early tumor progression after local ablative therapy remain an unmet clinical need. The aim of this study was to investigate circulating miR-21 and miR-210 levels as prognostic biomarkers of HCC treated by CT-guided high-dose rate brachytherapy (HDR-BT). MATERIALS AND METHODS: 24 consecutive HCC patients (BCLC A and B) treated with CT-guided HDR-BT (1 × 15 Gy) were included in this prospective IRB-approved study. RT-PCR was performed to quantify miR-21 and miR-210 levels in blood samples acquired prior to and 2 d after HDR-BT. Follow-up imaging (contrast-enhanced liver MRI and whole-body CT) was performed in 3 months follow-up intervals. Therapy response was assessed with patients classified as either responders or non-responders (12 each). Responders were defined as having no local or diffuse systemic progression within 6 months and no diffuse systemic progression exceeding 3 nodules/nodule diameter > 3 cm from 6 months to 2 years. Non-responders had recurrence within 6 months and/or tumor progression with > 3 nodules or individual lesion diameter > 3 cm or extrahepatic disease within two years, respectively. Biostatistics included parametric and non-parametric testing (Mann-Whitney-U-test), as well as Kaplan-Meier curve construction. RESULTS: The responder group demonstrated significantly decreasing miR-21 values 2 d post therapy compared to non-responders (median miR-21 2-ΔΔCт: responders 0.73 [IQR 0.34], non-responders 1.53 [IQR 1.48]; p = 0.0102). miR-210 did not show any significant difference between responders and non-responders (median miR-210 2-ΔΔCт: responders 0.74 [IQR 0.45], non-responders 0.99 [IQR 1.13]; p = 0.8399). Kaplan-Meier curves demonstrated significantly shorter time to systemic progression for increased miR-21 (p = 0.0095) but not miR-210 (p = 0.7412), with events accumulating > 1 year post therapy in non-responders (median time to systemic progression 397 days). CONCLUSION: Increasing circulating miR-21 levels are associated with poor response and shorter time to systemic progression in HDR-BT-treated HCC. This proof-of-concept study provides a basis for further investigation of miR-21 as a prognostic biomarker and potential stratifier in future clinical trials of interventional oncology therapies. TRIAL REGISTRATION: In this monocentric clinical study, we analyzed prospectively acquired data of 24 patients from the "ESTIMATE" patient cohort (Studiennummer: DRKS00010587, Deutsches Register Klinischer Studien). Ethical approval was provided by the ethics committee "Ethikkommission bei der LMU München" (reference number "17-346") on June 20, 2017 and August 26, 2020.

Agonist of RORA Attenuates Nonalcoholic Fatty Liver Progression in Mice via Up-regulation of MicroRNA 122.

BACKGROUND & AIMS: Development of nonalcoholic steatohepatitis (NASH) is associated with reductions in hepatic microRNA122 (MIR122); the RAR related orphan receptor A (RORA) promotes expression of MIR122. Increasing expression of RORA in livers of mice increases expression of MIR122 and reduces lipotoxicity. We investigated the effects of a RORA agonist in mouse models of NASH. METHODS: We screened a chemical library to identify agonists of RORA and tested their effects on a human hepatocellular carcinoma cell line (Huh7). C57BL/6 mice were fed a chow or high-fat diet (HFD) for 4 weeks to induce fatty liver. Mice were given hydrodynamic tail vein injections of a MIR122 antagonist (antagomiR-122) or a control antagomiR once each week for 3 weeks while still on the HFD or chow diet, or intraperitoneal injections of the RORA agonist RS-2982 or vehicle, twice each week for 3 weeks. Livers, gonad white adipose, and skeletal muscle were collected and analyzed by reverse-transcription polymerase chain reaction, histology, and immunohistochemistry. A separate group of mice were fed an atherogenic diet, with or without injections of RS-2982 for 3 weeks; livers were analyzed by immunohistochemistry, and plasma was analyzed for levels of aminotransferases. We analyzed data from liver tissues from patients with NASH included in the RNA-sequencing databases GSE33814 and GSE89632. RESULTS: Injection of mice with antagomiR-122 significantly reduced levels of MIR122 in plasma, liver, and white adipose tissue; in mice on an HFD, antagomiR-122 injections increased fat droplets and total triglyceride content in liver and reduced ß-oxidation and energy expenditure, resulting in significantly more weight gain than in mice given the control microRNA. We identified RS-2982 as an agonist of RORA and found it to increase expression of MIR122 promoter activity in Huh7 cells. In mice fed an HFD or atherogenic diet, injections of RS-2982 increased hepatic levels of MIR122 precursors and reduced hepatic synthesis of triglycerides by reducing expression of biosynthesis enzymes. In these mice, RS-2982 significantly reduced hepatic lipotoxicity, reduced liver fibrosis, increased insulin resistance, and reduced body weight compared with mice injected with vehicle. Patients who underwent cardiovascular surgery had increased levels of plasma MIR122 compared to its levels before surgery; increased expression of plasma MIR122 was associated with increased levels of plasma free fatty acids and levels of RORA. CONCLUSIONS: We identified the compound RS-2982 as an agonist of RORA that increases expression of MIR122 in cell lines and livers of mice. Mice fed an HFD or atherogenic diet given injections of RS-2982 had reduced hepatic lipotoxicity, liver fibrosis, and body weight compared with mice given the vehicle. Agonists of RORA might be developed for treatment of NASH.