Project description:The effects of GATA4 silencing on global gene expression in HUH6 hepatoblastoma cells was analyzed. Using microarray analysis we identified a set of genes that are downregulated or upregulated following silencing of GATA4 in HUH6 cell line.
Project description:GATA4 is frequently epigenetically silenced in lung cancers. However, the impact of GATA4 inactivation on tumorigenesis and related therapeutic strategy remain to be determined. Through the genome-wide screening of tumor suppressing transcription factors, we demonstrate that GATA4 functions as an essential tumor suppressor in lung cancer in vitro and in vitro. Interestingly, ectopic GATA4 expression resulted in cellular senescence. Mechanistically, GATA4 up-regulates multiple miRNAs (miRNA-32, miRNA-301b, miR-320a, and miR-590) targeting TGFB2 mRNA and causes ensuing downregulation of WNT7B level to induce senescence. TGFBRI inhibitor synergizes with MEK1/2 inhibitor to promote lung cancer regression in Kras G12D/GATA4-/- mouse models. Decreased GATA4 level in clinical specimens negatively correlates with WNT7B or TGFB2 level and is significantly associated with poor prognosis.
Project description:Hepatoblastoma is a primary malignant liver tumor in children, thought to arise from abnormal liver development during the fetal period. Approximately 90% of cases harbor activating mutations in CTNNB1, which encodes β-catenin, while other genetic mutations are rare. Recent studies have shown that CTNNB1 mutations are frequently accompanied by increased expression of the transcriptional coactivator YAP, which promotes cell proliferation and suppresses apoptosis. Based on these findings, we established a hepatoblastoma model by introducing active forms of CTNNB1 and YAP into human iPSC-derived hepatoblasts. Cells transduced with both genes showed distinct morphological changes and upregulation of CTNNB1, YAP, and their downstream target genes. RNA-seq followed by Gene Set Enrichment Analysis (GSEA) revealed that the gene expression profile of these cells closely matches that of hepatoblastoma patients. Utilizing this model, we identified Prostate-Associated Gene 4 (PAGE4) as a novel candidate gene involved in hepatoblastoma progression. Functional analysis in hepatoblastoma cell lines (Huh6, HepG2) demonstrated that PAGE4 plays a role in promoting cell proliferation and resistance to apoptosis. Since PAGE4 is a known cancer/testis antigen with tumor-specific expression, it has been recognized as a potential target in cancer therapy. Our findings indicate that PAGE4 represents a novel and promising therapeutic target for hepatoblastoma.
Project description:GATA4 is frequently epigenetically silenced in lung cancers. However, the impact of GATA4 inactivation on tumorigenesis and related therapeutic strategy remain to be determined. Through the genome-wide screening of tumor suppressing transcription factors, we demonstrate that GATA4 functions as an essential tumor suppressor in lung cancer in vitro and in vitro. Interestingly, ectopic GATA4 expression resulted in cellular senescence. Mechanistically, GATA4 up-regulates multiple miRNAs (miRNA-32, miRNA-301b, miR-320a, and miR-590) targeting TGFB2 mRNA and causes ensuing downregulation of WNT7B level to induce senescence. TGFBRI inhibitor synergizes with MEK1/2 inhibitor to promote lung cancer regression in Kras G12D/GATA4-/- mouse models. Decreased GATA4 level in clinical specimens negatively correlates with WNT7B or TGFB2 level and is significantly associated with poor prognosis.
Project description:GATA4 is frequently epigenetically silenced in lung cancers. However, the impact of GATA4 inactivation on tumorigenesis and related therapeutic strategy remain to be determined. Through the genome-wide screening of tumor suppressing transcription factors, we demonstrate that GATA4 functions as an essential tumor suppressor in lung cancer in vitro and in vitro. Interestingly, ectopic GATA4 expression resulted in cellular senescence. Mechanistically, GATA4 up-regulates multiple miRNAs (miRNA-32, miRNA-301b, miR-320a, and miR-590) targeting TGFB2 mRNA and causes ensuing downregulation of WNT7B level to induce senescence. TGFBRI inhibitor synergizes with MEK1/2 inhibitor to promote lung cancer regression in Kras G12D/GATA4-/- mouse models. Decreased GATA4 level in clinical specimens negatively correlates with WNT7B or TGFB2 level and is significantly associated with poor prognosis.
Project description:The mechanisms underlying hepatoblastoma are not well defined. To address this, we generated transcriptomic profiles of normal, background, and hepatoblastoma liver samples from patients aged 0.01 months to 6 years, using RNA-sequencing. Hepatoblasoma was histologically confirmed. Here we focus on the elevation of stem cell markers and the loss of tumor suppressor proteins leading to the development of hepatoblastoma in very young children.
Project description:Hepatoblastoma remains one of the most difficult childhood tumors to treat and is alarmingly understudied. Over half of patients initially present with locally advanced or metastatic disease and the prognosis for this cohort remains dismal. In addition, many of these children have disease that is resistant to standard therapies and will require novel and targeted therapies to effectively treat or manage their disease. We previously demonstrated that Proviral Insertion site in Maloney murine leukemia virus (PIM) kinases, specifically PIM3, are overexpressed in human hepatoblastoma cells and function to promote tumorigenesis. We aimed to use CRISPR/Cas9 gene editing technology with dual gRNAs to introduce large inactivating deletions in the PIM3 gene and achieve stable PIM3 knockout (KO) in the human hepatoblastoma cell line, HuH6. PIM3 KO of hepatoblastoma cells led to significantly decreased proliferation, viability, and motility, inhibited cell-cycle progression, decreased tumor growth in a xenograft murine model, and increased animal survival. Analysis of RNA sequencing data revealed that PIM3 KO downregulated expression of pro-migratory and pro-invasive genes and upregulated expression of genes involved in apoptosis and differentiation. Furthermore, PIM3 KO decreased hepatoblastoma cancer cell stemness as evidenced by decreased tumorsphere formation, decreased mRNA abundance of stemness markers, and decreased cell surface expression of CD133, a marker of hepatoblastoma stem cell-like cancer cells. Reintroduction of PIM3 into PIM3 KO cells rescued the malignant phenotype. These findings emphasize the role of PIM3 in promoting hepatoblastoma tumorigenesis and provide evidence that targeting PIM3 may offer a novel therapeutic approach for children with hepatoblastoma.