Project description:Sorafenib is a multi-kinase blocker and one of the few suggested drug treatments for aggressive hepatocellular carcinoma (HCC) patients. However, drug resistance to sorafenib may often occur over time and cause further tumor aggression. Recently, cancer stem cells were found in HCC and were speculated to be involved in tumor progression. SOX9 is highly expressed in HCC cancer stem cells and promotes cell proliferation and self-renewal. Meanwhile, HCC patients with higher SOX9 expression show poorer prognosis [1]. Whether SOX9 is involved in sorafenib resistance in HCC is still unclear. Here, we found that sorafenib treatment increased SOX9 expression in HCC cell lines. Overexpression of exogenous SOX9 in HCC increased sorafenib resistance both in vitro and in vivo, whereas down-regulation led to inhibition of sorafenib resistance. Knock-down of SOX9 by RNA interference caused down-regulation of downstream genes, including ATP binding cassette subfamily G member 2 (ABCG2). The drug resistance to sorafenib caused by SOX9 overexpression could be ameliorated by overexpression of SOX9 in combination withby ABCG2 inhibition in HCC cell lines. In the cohort of patients resistant to sorafenib, we found that patients with lower SOX9 expression had more prolonged overall survival (OS) and progression-free survival (PFS). Cox analysis shows that SOX9 expression exerts as an independent risk factor for HCC, and logistic regression analysis reveals that SOX9 expression, tumor capsule deficiency, tumor diameters, and microvascular invasion are risk factors for poor prognosis of HCC patients. These findings demonstrate that SOX9 enhances sorafenib resistance and may regulate this process by modulating ABCG2 expression.
Project description:Introduction: In addition to the well-known cartilage extracellular matrix-related expression of Sox9, we demonstrated that chondrogenic differentiation of progenitor cells is driven by a sharply defined bi-phasic expression of Sox9: an immediate early and a late (extracellular matrix associated) phase expression. In this study we aimed to determine what biological processes are driven by Sox9 during this early phase of chondrogenic differentiation. Materials: Sox9 expression in ATDC5 cells was knocked-down by siRNA transfection at the day before chondrogenic differentiation or at day 6 of differentiation. Samples were harvested at 2 hours, and 7 days of differentiation. The transcriptomes (RNA-seq approach) and proteomes (Label-free proteomics approach) were compared using pathway and network analyses. Total protein translational capacity was evaluated with the SuNSET assay, active ribosomes with polysome profiling and ribosome modus with bicistronic reporter assays. Results: Early Sox9 knockdown severely inhibited chondrogenic differentiation weeks later. Sox9 expression during the immediate early phase of ATDC5 chondrogenic differentiation regulated the expression of ribosome biogenesis factors and ribosomal protein subunits. This was accompanied by decreased translational capacity following Sox9 knockdown, and this correlated to lower amounts of active mono- and polysomes. Moreover, cap- versus IRES-mediated translation was altered by Sox9 knockdown. Sox9 overexpression was able to induce reciprocal effects to the Sox9 knockdown. Conclusion: Here we identified an essential new function for Sox9 during early chondrogenic differentiation. A role for Sox9 in regulation of ribosome amount, activity and/or composition may be crucial in preparation for the demanding proliferative phase and subsequent cartilage extracellular matrix-production of chondroprogenitors in the growth plate in vivo.
Project description:HCC cell line, Huh-7 cells and HCC-LM3 cells, was transfected with sh-WDR4-2 or sh-NC for 48hr to knockdown WDR4 expression, and check the downstream mRNA changes.
Project description:Staphylococcal nuclease domain-containing protein 1 (SND1) is overexpressed in human hepatocellular carcinoma (HCC) and positively regulates development and progression of HCC. We established stable clones expressing SND1 shRNA in QGY-7703 cells and analyzed the gene expression profiles of a control clone and two SND1 knockdown clones to check what genes are regulated by SND1. Steady-state proliferating cells were collected for RNA extraction and Affymetrix microarray hybridization. Three biological replicates each of a control clone and 2 SND1 knockdown clones.
Project description:Human ß cell dedifferentiation as a potent mechanism of diabetes is gaining prominence. Several data suggest an upregulation of the transcription factor SOX9, a progenitor and duct cell marker during ß cell dedifferentiation. However, its targets in such cells need more understanding. Here, we overexpressed SOX9 and a constitutively active mutant (VP16-SOX9∆TAD) in Human pancreatic beta EndoC-ßH1 cells in order to understand its targets.
Project description:Staphylococcal nuclease domain-containing protein 1 (SND1) is overexpressed in human hepatocellular carcinoma (HCC) and positively regulates development and progression of HCC. We established stable clones expressing SND1 shRNA in QGY-7703 cells and analyzed the gene expression profiles of a control clone and two SND1 knockdown clones to check what genes are regulated by SND1.