Erratum: Wagner, A.E., et al. SP8 Promotes an Aggressive Phenotype in Hepatoblastoma via FGF8 Activation. Cancers 2020, 12, 2294.

Two contributors' names were missing in the original version of the authorship of the paper [...].

SP8 Promotes an Aggressive Phenotype in Hepatoblastoma via FGF8 Activation.

Hepatoblastoma (HB) is the most common malignant liver tumor in childhood and it generally has a good prognosis. However, if associated with aggressive metastatic disease, outcome is still poor. The molecular mechanisms leading to metastatic spread in HB patients are still unknown. By combining RNA-sequencing and a genome-wide methylome analysis, we identified the transcription factor SP8 and the growth factor FGF8 among the most strongly upregulated genes in metastatic HB cases, with a concomitant robust demethylation of the respective promoter regions. Of note, high expression of both candidates was associated with the aggressive C2 subtype of the 16-gene signature and poor survival. Chromatin immunoprecipitation revealed a direct transcriptional regulation of FGF8 through binding of SP8 to the FGF8 promoter. Gain- and loss-of-function experiments proved promoting effects of SP8 on motility, self-renewal, migration, and the invasive potential of HB cells. Moreover, stable overexpression of SP8 in Hep3B cells resulted in the acquisition of a mesenchymal phenotype and a strong upregulation of epithelial-mesenchymal transition-associated genes. Using KRAB-mediated CRISPR-dCas9 interference directed against FGF8, we could show that FGF8 is essential for the SP8-mediated aggressive tumor behavior. Treatment of HB cell lines with the pan SP family inhibitor mithramycin A resulted in a significant inhibition of their clonogenic growth. In summary, we identified SP8 and FGF8 as key players in aggressive traits of HB and propose SP8 inhibiting drugs as a new effective treatment strategy especially for metastatic tumors.

High expression of IGF2-derived intronic miR-483 predicts outcome in hepatoblastoma.

BACKGROUND: The role of microRNAs (miRs) as biomarkers to predict outcome in hepatoblastoma (HB), the most common malignant liver tumor in childhood, has still to be determined. Recently, the so-called four-miR signature has been described to efficiently stratify HB patients according to their prognosis. OBJECTIVE: We examined the recently described four-miR signature for its clinical relevance in an independent validation cohort of HB patients and tried to optimize its predictive value by analyzing four additional miRs involved in HB biology. METHODS: Expression of eight miR was determined in 29 tumor and 10 normal liver samples by TaqMan assays and association studies and Kaplan-Meier estimators determined their clinical relevance. RESULTS: Stratifying HB patients by the four-miR signature showed no difference in patients' outcome, which was also reflected by the lack of association with any clinical risk parameter. Adding miR-23b-5p and miR-23b-3p did also not increase its discriminating power. However, the integration of miR-483-5p and miR-483-3p into the four-miR signature could predict patients with poor outcome that were associated with large tumors and vessel invasive growth with high accuracy. CONCLUSIONS: The expansion of the four-miR signature by miR-483 serves as a useful biomarker to predict outcome of HB patients.