Shangguan, W. | bioRxiv Science

bioRxiv2024

Fibrillarin modulates fetal hemoglobin silencing

Decoding the molecular mechanisms underlying human fetal ({gamma}) globin gene silencing impacts therapeutic strategies for {beta}-thalassemia and sickle cell disease. Here, we identified a nucleolar protein, fibrillarin (FBL), which mediates the methylation of glutamine104 in histone H2A and functions as a repressor of the {gamma}-globin gene in cultured erythroid cells, including those from {beta}-thalassemia patients. Conditional Fbl depletion in adult {beta}-YAC transgenic mice or in {beta}IVS-2-654-thalassemic mice reactivated the human {gamma}-globin gene or murine embryonic globin expression, respectively, which corrects hematologic and pathologic defects in {beta}-thalassemic mice. We showed that FBL plays a dual role in activating BCL11A expression and repressing {gamma}-globin gene expression, which is dependent on its histone methyltransferase activity. Our study may provide an alternative strategy for therapeutic targeted treatment of {beta}-hemoglobinopathies.

molecular biology↗

bioRxiv2018

Lin28B is involved in curcumin-reversed paclitaxel chemoresistance and associated with poor prognosis in hepatocellular carcinoma

Chemoresistance remains a big challenge in hepatocellular carcinoma (HCC) treatment. Several studies indicated that RNA-binding protein Lin28B serves an oncogenic role in HCC, but its activity in HCC chemotherapy has never been assessed. In this study, we found that overexpression of Lin28B significantly increased the paclitaxel chemoresistance in two different HCC cells lines while silencing Lin28B reduced the chemoresistance in paclitaxel-resistance HCC cells. Curcumin, a natural anti-cancer agent, increased the sensitivity of HCC cells to paclitaxel through inhibiting NF-{kappa}B stimulated Lin28B expression both in vitro and in vivo. Furthermore, by analyzing TCGA (The Cancer Genome Atlas) LIHC (liver hepatocellular carcinoma) and GSE14520 databases, we found that Lin28B was highly up-regulated in HCC tissue compared with that in normal tissue and associated with -fetoprotein levels, and that patients with Lin28B higher expression had a significant shorter overall survival time than those with Lin28B lower expression. Our data reveal that Lin28B may serve as a predictive biomarker and a treatment target to reverse HCC chemotherapy resistance in future clinical practice.\n\nSummary statementupregulation of Lin28B not only confers poor prognosis in HCC patients but also increases chemoresistance in HCC cells. Thus, Lin28B may serve as a predictive biomarker for use to reverse chemoresistance in clinical practice.

cell biology↗