Project description:We performed microarray analyses to examine whether TAp63alpha is able to induce the expression of several pro-apoptotic and immunosystem related genes in Hep3B (hepatoma) cells. We investigated the downstream mechanisms by which TAp53 elicits apoptosis.
Project description:Hep3B cells were treated with the chemotherapeutic drug bleomycin. RNA was isolated after 18 h, 24 h and 36 h. The status of the gene expression was examined in response to treatment with bleomycin,
Project description:Methylation of CpG islands is associated with transcriptional repression and, in cancer, leads to the abnormal silencing of tumor-suppressor genes. Genome wide methylation profiling of myeloid leukemia cell lines identified a large number of genes with aberrantly methylated CpG islands. Comparative mRNA expression analysis suggests that more than half of these genes show extremely low or absent expression in normal cells, suggesting that hypermethylation in cancer may be independent of the transcriptional status of the affected gene. Experiment Overall Design: The expression profiles of the three leukemia cell lines KG-1, U937 and THP-1 was compared to normal human blood monocytes (reference). The set includes a single hybridization for each sample.
Project description:The aim of the experiment was to analyse the gene expression differences between MEFs containing TAp73 or without TAp73, at basal levels in normal culture conditions, and upon treatment with hypoxia (by incubation in 1% oxygen) for 4 or 8 hrs. The analysis indicate that absence of TAp73 leads to changes in multiple cellular and biological processes.
Project description:The aim of the experiment was to analyse the gene expression differences between MEFs containing TAp73 or without TAp73, at basal levels in normal culture conditions, and upon treatment with hypoxia (by incubation in 1% oxygen) for 4 or 8 hrs. The analysis indicate that absence of TAp73 leads to changes in multiple cellular and biological processes. TAp73-/- and Tap73+/+ MEFs that were untreated, or treated with hypoxia (in 1% oxygen) for 4 and 8 hours were used for gene expression analysis
Project description:Although being essential to respiratory and reproductive tracts multiciliogenesis, TAp73 is dispensable for multiciliogenesis in the ventricles. TAp73 KO is accompanied by dramatic changes in ciliogenic microRNAs miR34bc and miR449 family members, suggestin TAp73 functions partially thorugh posttranscriptional nodes in brain ciliogenesis.
Project description:Hepatocyte dedifferentiation is a major source of hepatocellular carcinoma (HCC), but its mechanisms are unknown. We explored the p73 expression in HCC tumors and studied the effects of transcriptionally active p73 (TAp73) in HCC cells. Expression profiles of p73 and patient clinical data were collected from the Genomic Data Commons (GDC) data portal and the TSVdb database, respectively. Global gene expression profiles were determined by pan-genomic 54K microarrays. The Gene Set Enrichment Analysis was used to identify TAp73-regulated gene sets. The effects of TAp73 were analyzed in monolayer cell culture, 3D-tumoroid and xenograft models in zebrafish using western blot, flow cytometry, fluorescence imaging, real-time polymerase chain reaction (RT-PCR), immunohistochemistry and morphological examination. TAp73 was significantly upregulated in HCC, and its high expression indicated poor patient survival. The induced expression of TAp73 caused landscape expression changes including genes involved in growth signaling, cell cycle, stress response, immunity, metabolism and development. HCC cells overexpressing TAp73 had lost hepatocyte lineage biomarkers including ALB, CYP3A4, AFP, HNF4α. In contrast, TAp73 upregulated genes promoting cholangiocyte lineage such as YAP, JAG1 and ZO-1, accompanied with an increase in metastatic ability. Our findings strongly suggest that TAp73 is a major promoter of malignant dedifferentiation of HCC cells Hepatocellular carcinoma (HCC) is a highly complex and heterogeneous type of cancer. Hepatocyte dedifferentiation is one of the important steps in the development of HCC. However, its molecular mechanisms are not well known. In this study, we report that TAp73 which is the major transcriptionally active form of p73 is overexpressed in HCC. Mechanically, TAp73 suppresses the expression of the hepatocyte markers including CYP3A4, AFP, ALB, HNF4a, while increasing the expression of several cholangiocyte markers in HCC cell lines. In conclusion, this report reveals a pro-oncogenic role for TAp73 in liver cancer.
Project description:Cancer stem cells (CSCs) are resistant to conventional chemotherapy and are hence responsible for cancer relapse. Pluripotency is a characteristic of CSCs which allows them to rapidly proliferate while maintaining the ability to differentiate into various lineages. We found that TAp73, but not its homologue p53, is required for the pluripotency of CSCs. TAp73 knockdown (KD) decreased SOD1 levels, increased ROS production and disturbed metabolism which induced differentiation and abrogated pluripotency in CSCs. TAp73 related decrease in pluripotency is linked to increased autophagy and senescence in CSCs. Furthermore, TAp73 KD also decreased the levels of pluripotency factor Sox-2 within heterogeneous cancer cell lines. Interestingly, TAp73-deficient CSCs strongly lose tumorigenic potential in mice and tumors that did form had significantly lower levels of SOD1 and pluripotency marker Oct4. Our findings reveal a unique role of TAp73 in CSCs development that is important to consider while devising future therapeutic strategies against cancer.
Project description:Changes in tissue homeostasis, acquisition of invasive cell characteristics and tumor formation can often be linked to the loss of epithelial cell polarity. In carcinogenesis, the grade of neoplasia correlates with impaired cell polarity. In Drosophila, lgl, dlg and scribble, which are components of the epithelial apico-basal cell polarity machinery, act as tumor suppressors and orthologs of this evolutionary conserved pathway are lost in human carcinoma with high frequency. However, a mechanistic link between neoplasia and vertebrate orthologs of these tumor suppressor genes remains to be fully explored at the organismal level. Here, we show that the pen/lgl2 mutant phenotype shares two key cellular and molecular features of mammalian malignancy: cell autonomous epidermal neoplasia and epithelial-to-mesenchymal-transition (EMT) of basal epidermal cells including the differential expression of several regulators of EMT. Further we found that epidermal neoplasia and EMT in pen/lgl2 mutant epidermal cells is promoted by ErbB signalling, a pathway of high significance in human carcinomas. Intriguingly, EMT in the pen/lgl2 mutant is facilitated specifically by ErbB2 mediated E-cadherin mislocalization and not via canonical snail dependent down-regulation of E-cadherin expression. Our data reveal that pen/lgl2 functions as a tumor suppressor gene in vertebrates, establishing zebrafish pen/lgl2 mutants as a valuable cancer model.