HOX genes encode a family of homeodomain-containing transcription factors involved in the determination of cell fate and identity during embryonic development. They also behave as oncogenes in some malignancies. In this study, we found high expression of the HOXD9 gene transcript in glioma cell lines and human glioma tissues by quantitative real-time PCR. Using immunocytochemistry, we observed HOXD9 protein expression in human brain tumor tissues, including astrocytomas and glioblastomas. To investigate the role of HOXD9 in gliomas, we silenced its expression in the glioma cell line U87 using HOXD9-specific siRNA, and observed decreased cell proliferation, cell cycle arrest, and induction of apoptosis. It was suggested that HOXD9 contributes to both cell proliferation and/or cell survival. The HOXD9 gene was highly expressed in a side population (SP) of SK-MG-1 cells that was previously identified as an enriched-cell fraction of glioma cancer stem-like cells. HOXD9 siRNA treatment of SK-MG-1 SP cells resulted in reduced cell proliferation. Finally, we cultured human glioma cancer stem cells (GCSCs) from patient specimens found with high expression of HOXD9 in GCSCs compared with normal astrocyte cells and neural stem/progenitor cells (NSPCs). Our results suggest that HOXD9 may be a novel marker of GCSCs and cell proliferation and/or survival factor in gliomas and glioma cancer stem-like cells, and a potential therapeutic target.
Functional analysis of HOXD9 in human gliomas and glioma cancer stem cells.
Cell line
View SamplesNasu-Hakola disease (NHD), also designated polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), is a rare autosomal recessive disorder characterized by progressive presenile dementia and formation of multifocal bone cysts, caused by a loss-of-function mutation of DAP12 or TREM2. TREM2 and DAP12 constitute a receptor/adaptor complex expressed on osteoclasts, dendritic cells, macrophages, monocytes, and microglia. At present, the precise molecular mechanisms underlying development of leukoencephalopathy and bone cysts in NHD remain largely unknown. We established THP-1 human monocyte clones that stably express small interfering RNA (siRNA) targeting DAP12 for serving as a cellular model of NHD. Genome-wide transcriptome analysis identified a set of 22 genes consistently downregulated in DAP12 knockdown cells. They constituted the molecular network closely related to the network defined by cell-to-cell signaling and interaction, hematological system development and function, and inflammatory response, where NF-kappaB acts as a central regulator. These results suggest that a molecular defect of DAP12 in human monocytes deregulates the gene network pivotal for maintenance of myeloid cell function in NHD. We found that both DAP12 knockdown and control clones were capable of equally responding to phorbol 12-myristate 13-acetate (PMA), a known inducer of morphological differentiation of THP-1 cells, by exhibiting almost similar gene expression profiles between both, following a 24-hour exposure to 50 nM PMA.
Gene expression profile of THP-1 monocytes following knockdown of DAP12, a causative gene for Nasu-Hakola disease.
Specimen part
View SamplesNasu-Hakola disease (NHD), also designated polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), is a rare autosomal recessive disorder characterized by progressive presenile dementia and formation of multifocal bone cysts, caused by a loss-of-function mutation of DAP12 or TREM2. TREM2 and DAP12 constitute a receptor/adaptor complex expressed on osteoclasts, dendritic cells, macrophages, monocytes, and microglia. At present, the precise molecular mechanisms underlying development of leukoencephalopathy and bone cysts in NHD remain largely unknown. We established THP-1 human monocyte clones that stably express small interfering RNA (siRNA) targeting DAP12 for serving as a cellular model of NHD. Genome-wide transcriptome analysis identified a set of 22 genes consistently downregulated in DAP12 knockdown cells. They constituted the molecular network closely related to the network defined by cell-to-cell signaling and interaction, hematological system development and function, and inflammatory response, where NF-kappaB acts as a central regulator. These results suggest that a molecular defect of DAP12 in human monocytes deregulates the gene network pivotal for maintenance of myeloid cell function in NHD.
Gene expression profile of THP-1 monocytes following knockdown of DAP12, a causative gene for Nasu-Hakola disease.
Specimen part, Cell line
View SamplesHere we uncover antagonistic regulation of transcript levels in the germline of Caenorhabditis elegans hermaphrodites. The histone methyltransferase MES-4 marks genes expressed in the germline with methylated Lys36 on histone H3 (H3K36me) and promotes their transcription; MES-4 also represses genes normally expressed in somatic cells and genes on the X chromosomes. The DRM complex, which includes E2F/DP and Retinoblastoma homologs, affects germline gene expression and prevents excessive repression of X-chromosome genes. Using genome-scale analyses of germline tissue, we show that common germline-expressed genes are activated by MES-4 and repressed by DRM, and that MES-4 and DRM co-bind many germline-expressed genes. Reciprocally, MES-4 represses and DRM activates a set of autosomal soma-expressed genes and overall X-chromosome gene expression. Mutations in mes-4 or the DRM subunit lin-54 oppositely skew target transcript levels and cause sterility; a double mutant restores near wild-type transcript levels and germ cell development. Together, yin-yang regulation by MES-4 and DRM ensures transcript levels appropriate for germ cell function, elicits robust but not excessive dampening of X-chromosome-wide transcription, and may poise genes for future expression changes. Our study reveals that conserved transcriptional regulators implicated in development and cancer counteract each other to fine-tune transcript dosage.
Opposing activities of DRM and MES-4 tune gene expression and X-chromosome repression in Caenorhabditis elegans germ cells.
Sex
View SamplesHyperthermia (HT) treatments in combination with either chemotherapy, radiotherapy or both are used for patients with cancer in various organs. However, the acquisition of thermotolerance in cancer cells due to the increase in cytoprotective proteins attenuates the therapeutic effects of HT. BAG3 (BCL2-associated athanogene 3) is a cytoprotective protein that acts against various stresses including heat stress. Recently, we demonstrated that the inhibition of BAG3 improves cell death sensitivity to HT in cancer cells. However, a detailed molecular mechanism involved in the enhancement of HT sensitivity by BAG3-knockdown (KD) in cancer cells is unclear.
Network analysis of genes involved in the enhancement of hyperthermia sensitivity by the knockdown of BAG3 in human oral squamous cell carcinoma cells.
Sex, Age, Specimen part, Cell line
View SamplesHyperthermia (HT) is widely used to treat patients with various cancers. In general, HT elicits a wide spectrum of stress responses, such as induction of heat shock proteins, protein aggregation and cell death in mammalian cells. Although many biological processes are affected by HT, the overall responses to HT in mammalian cells remain unknown.
Identification of common gene networks responsive to mild hyperthermia in human cancer cells.
Specimen part, Cell line, Treatment, Time
View SamplesHyperthermia (HT) is widely used to treat patients with various cancers. In general, HT elicits a wide spectrum of stress responses such as induction of heat shock proteins, protein aggregation and cell death in mammalian cells. Although many biological processes are affected by HT, the overall responses to HT in mammalian cells remain unknown.
Identification of common gene networks responsive to mild hyperthermia in human cancer cells.
Sex, Age, Specimen part, Cell line, Treatment
View SamplesHyperthermia is widely used to treat patients with various cancers. The 42.5C is well known as inflection point of hyperthermia and generally up to 42C of hyperthermia is used in clinical case to combine with other therapy. Here, the effects of heat stress at 42 or 44C for 90 min on the gene expression in HSC-3 human oral squamous carcinoma cells were investigated using an Affymetrix GeneChip system. The cells were treated with heat stress (42 or 44C for 90 min) and followed by incubation for 0, 6, or 12 h at 37C. The percentage of cell death was 5.0 1.5 (mean SD) at 42C for 12 h and 17.4 0.6 at 44C for 12 h. Of approximately 47,000 probe sets analyzed, many genes that were differentially expressed by a factor 2.0 or greater were identified in the cells treated with heat stress at 42 and 44C.
Gene networks related to the cell death elicited by hyperthermia in human oral squamous cell carcinoma HSC-3 cells.
Cell line, Treatment, Time
View SamplesAlthough an appropriate range of fluoride is thought to be safe and effective, excessive fluoride intake results in toxic effects in either hard tissues of teeth and skeleton or soft tissues of kidney, lung and brain. It is also well known that fluoride at a millimolar range elicits the complex cellular responses such as enzyme activity, signal transduction and apoptosis in many kinds of cells. However, its toxic effects are still unclear.
Genes and gene networks involved in sodium fluoride-elicited cell death accompanying endoplasmic reticulum stress in oral epithelial cells.
Specimen part, Cell line, Treatment, Time
View SamplesBackground: Glioblastoma is the most aggressive form of brain tumors showing resistance to treatment with various chemotherapeutic agents. The most effective way to eradicate glioblastoma requires the concurrent inhibition of multiple signaling pathways and target molecules involved in the progression of glioblastoma. Recently, we obtained a series of 1,2,3,4-tetrahydroisoquinoline alkaloids with potent anti-cancer activities, including ecteinascidin-770 (ET-770; the compound 1a) and renieramycin M (RM; the compound 2a) from Thai marine invertebrates, together with a 2-N-4-pyridinecarbonyl derivative of ET-770 (ET-770-DR; the compound 3). We attempted to characterize the molecular pathways responsible for cytotoxic effects of these compounds on a human glioblastoma cell line U373MG. Methods: We studied the genome-wide gene expression profile on microarrays and molecular networks by using pathway analysis tools of bioinformatics. Results: All of these compounds dissolved in dimethyl sulfoxide (DMSO) as a vehicle induced apoptosis of U373MG cells at nanomolar concentrations. The compound 3 reduced the expression of 417 genes and elevated the levels of 84 genes, while ET-770 downregulated 426 genes and upregulated 45 genes. RM decreased the expression of 274 genes and increased the expression of 9 genes. The set of 196 downregulated genes and 6 upregulated genes showed an overlap among all the compounds, suggesting an existence of the common pathways involved in induction of apoptosis. We identified the ErbB (EGFR) signaling pathway as one of the common pathways enriched in the set of downregulated genes, composed of PTK2, AKT3, and GSK3B serving as key molecules that regulate cell movement and the nervous system development. Furthermore, a GSK3B-specific inhibitor induced apoptosis of U373MG cells, supporting an anti-apoptotic role of GSK3B. Conclusion: Molecular network analysis is a useful approach not only to characterize the glioma-relevant pathways but also to identify the network-based effective drug targets.
Molecular network profiling of U373MG human glioblastoma cells following induction of apoptosis by novel marine-derived anti-cancer 1,2,3,4-tetrahydroisoquinoline alkaloids.
Specimen part, Cell line, Treatment
View Samples