GT198 Expression Defines Mutant Tumor Stroma in Human Breast Cancer

Human breast cancer precursor cells remain to be elucidated. Using breast cancer gene product GT198 (PSMC3IP; alias TBPIP or Hop2) as a unique marker, we revealed the cellular identities of GT198 mutant cells in human breast tumor stroma. GT198 is a steroid hormone receptor coactivator and a crucial factor in DNA repair. Germline mutations in GT198 are present in breast and ovarian cancer families. Somatic mutations in GT198 are present in ovarian tumor stromal cells. Herein, we show that human breast tumor stromal cells carry GT198 somatic mutations and express cytoplasmic GT198 protein. GT198(+) stromal cells share vascular smooth muscle cell origin, including myoepithelial cells, adipocytes, capillary pericytes, and stromal fibroblasts. Frequent GT198 mutations are associated with GT198(+) tumor stroma but not with GT198(-) tumor cells. GT198(+) progenitor cells are mostly capillary pericytes. When tested in cultured cells, mutant GT198 induces vascular endothelial growth factor promoter, and potentially promotes angiogenesis and adipogenesis. Our results suggest that multiple lineages of breast tumor stromal cells are mutated in GT198. These findings imply the presence of mutant progenitors, whereas their descendants, carrying the same GT198 mutations, are collectively responsible for forming breast tumor microenvironment. GT198 expression is, therefore, a specific marker of mutant breast tumor stroma and has the potential to facilitate diagnosis and targeted treatment of human breast cancer

Emerging roles of lipid metabolism in cancer metastasis

Abstract Cancer cells frequently display fundamentally altered cellular metabolism, which provides the biochemical foundation and directly contributes to tumorigenicity and malignancy. Rewiring of metabolic programmes, such as aerobic glycolysis and increased glutamine metabolism, are crucial for cancer cells to shed from a primary tumor, overcome the nutrient and energy deficit, and eventually survive and form metastases. However, the role of lipid metabolism that confers the aggressive properties of malignant cancers remains obscure. The present review is focused on key enzymes in lipid metabolism associated with metastatic disease pathogenesis. We also address the function of an important membrane structure-lipid raft in mediating tumor aggressive progression. We enumerate and integrate these recent findings into our current understanding of lipid metabolic reprogramming in cancer metastasis accompanied by new and exciting therapeutic implications

Mesophase Pitch-Based Carbon Fibers: Accelerated Stabilization of Pitch Fibers under Effective Plasma Irradiation-Assisted Modification

Stabilization is the most complicated and time-consuming step in the manufacture of carbon fibers (CFs), which is important to prepare CFs with high performance. Accelerated stabilization was successfully demonstrated under effective plasma irradiation-assisted modification (PIM) of mesophase pitch fibers (PFs). The results showed that the PIM treatment could obviously introduce more oxygen-containing groups into PFs, which was remarkably efficient in shortening the stabilization time of PFs with a faster stabilization heating rate, as well as in preparing the corresponding CFs with higher performance. The obtained graphitized fiber (GF-5) from the PF-5 under PIM treatment of 5 min presented a higher tensile strength of 2.21 GPa, a higher tensile modulus of 502 GPa, and a higher thermal conductivity of 920 W/m·K compared to other GFs. Therefore, the accelerated stabilization of PFs by PIM treatment is an efficient strategy for developing low-cost pitch-based CFs with high performance

Alternative splicing switch from CoAA to CoAM during P19 embryonal carcinoma cell differentiation

<p><b>Copyright information:</b></p><p>Taken from "Switched alternative splicing of oncogene CoAA during embryonal carcinoma stem cell differentiation"</p><p></p><p>Nucleic Acids Research 2007;35(6):1919-1932.</p><p>Published online 1 Mar 2007</p><p>PMCID:PMC1874587.</p><p>© 2007 The Author(s)</p> () Undifferentiated P19 cells (EC) were induced with 500 nM retinoic acid (RA) in suspension culture up to 4 days to form embryoid bodies (EB2–EB4) which were trypsinized and further differentiated in the tissue culture dish for an additional 12 days in the absence of RA (D3–D12). Total RNA was isolated and normalized at each stage and analyzed using gene-specific primers as indicated by RT-PCR. GAPDH was the control. () CoAA and CoAM were analyzed by RT-PCR using shared primers. () The relative quantity of CoAA and CoAM was analyzed by quantitative real-time PCR. () Mouse ES cells were induced with 1 μM RA for 6 days. The EB was undisrupted in continuous culture for 15 days in the absence of RA. RT-PCR was carried out using RNA isolated at each stage

Negative effects of retinoic acid on stem cell niche of mouse incisor

AbstractThe continuous growth of mouse incisors depends on epithelial stem cells (SCs) residing in the SC niche, called labial cervical loop (LaCL). The homeostasis of the SCs is subtly regulated by complex signaling networks. In this study, we focus on retinoic acid (RA), a derivative of Vitamin A and a known pivotal signaling molecule in controlling the functions of stem cells (SCs). We analyzed the expression profiles of several key molecules of the RA signaling pathway in cultured incisor explants upon exogenous RA treatment. The expression patterns of these molecules suggested a negative feedback regulation of RA signaling in the developing incisor. We demonstrated that exogenous RA had negative effects on incisor SCs and that this was accompanied by downregulation of Fgf10, a mesenchymally expressed SC survival factor in the mouse incisor. Supplement of Fgf10 in incisor cultures completely blocked RA effects by antagonizing apoptosis and increasing proliferation in LaCL epithelial SCs. In addition, Fgf10 obviously antagonized RA-induced downregulation of the SC marker Sox2 in incisor epithelial SCs. Our findings suggest that the negative effects of RA on incisor SCs result from inhibition of mesenchymal Fgf10

Expression of CoAA in embryoid body of P19 cells and in brain of mouse embryo

<p><b>Copyright information:</b></p><p>Taken from "Switched alternative splicing of oncogene CoAA during embryonal carcinoma stem cell differentiation"</p><p></p><p>Nucleic Acids Research 2007;35(6):1919-1932.</p><p>Published online 1 Mar 2007</p><p>PMCID:PMC1874587.</p><p>© 2007 The Author(s)</p> () Evaluation of anti-RRM and anti-CoAA antibodies using western blot analysis by overexpression of CoAA and CoAM in 293 cells. () Light microscopy of P19 cells at indicated differentiation stages (×400). () Embryoid body at Day 4 was paraffin-embedded, sectioned and stained with anti-RRM (against both CoAA and CoAM), anti-CoAA (against CoAA only) and anti-active caspase-3 (against cleaved caspase-3) antibodies. Two representative views are shown (×400). Enlarged views are shown below. The results show CoAM and active caspase-3 staining in the EB cavity. () Western blot analysis of CoAA, CoAM and CoAR at indicated differentiation stages of P19 cells. () Immunohistochemistry analyses of mouse embryonic brain at gestation stages of E12.5 and E15.5. The sagittal sections were stained with affinity-purified anti-CoAA antibody (1:200) and counterstained with hematoxylin (×400)

Overexpression of CoAM and treatment with CoAA siRNA induce Sox6 expression in the absence of retinoic acid

<p><b>Copyright information:</b></p><p>Taken from "Switched alternative splicing of oncogene CoAA during embryonal carcinoma stem cell differentiation"</p><p></p><p>Nucleic Acids Research 2007;35(6):1919-1932.</p><p>Published online 1 Mar 2007</p><p>PMCID:PMC1874587.</p><p>© 2007 The Author(s)</p> P19 cells were transfected with CoAM or with CoAA-specific siRNA (25 nM) at the EC stage, and then were cultured in suspension for 4 days in the absence of RA induction. The cells were trypsinized, plated and further cultured for 3 days. The untreated and RA-induced (for 4 days) P19 cells were similarly cultured as controls. RT-PCR analyses were carried out with indicated marker genes at each indicated stage

Tentative model of CoAA alternative splicing regulation in the embryoid body of stem cells

<p><b>Copyright information:</b></p><p>Taken from "Switched alternative splicing of oncogene CoAA during embryonal carcinoma stem cell differentiation"</p><p></p><p>Nucleic Acids Research 2007;35(6):1919-1932.</p><p>Published online 1 Mar 2007</p><p>PMCID:PMC1874587.</p><p>© 2007 The Author(s)</p> CoAA is produced by alternative splicing with inclusion of the second exon. A competitive 5′ alternative splicing event excluding a portion of the second exon (2b) produces a dominant negative variant, CoAM, which lacks the activation domain. The basal promoter of the CoAA gene, shown as an open box, promotes splicing of the CoAA form, which is expressed in the outer layer of the embryoid body (gray). The upstream -regulating sequence, shown as a filled box, promotes alternative splicing of CoAM, which is expressed in the cavity of EB (white). The loss of upstream -regulating element in cancer may prevent the alternative splicing switch and disrupt stem cell differentiation

The Inhibition of miR-873 Provides Therapeutic Benefit in a Lipopolysaccharide-Induced Neuroinflammatory Model of Parkinson’s Disease

Background and Purpose. Alterations in cholesterol homeostasis have been reported in cell and animal models of Parkinson’s disease (PD), although there are inconsistent data about the association between serum cholesterol levels and risk of PD. Here, we investigated the effects of miR-873 on lysosomal cholesterol homeostasis and progressive dopaminergic neuron damage in a lipopolysaccharide-(LPS) induced model of PD. Experimental Approach. To evaluate the therapeutic benefit of the miR-873 sponge, rats were injected with a LV-miR-873 sponge or the control vector 3 days before the right-unilateral injection of LPS into the substantia nigra (SN) pars compacta, or 8 and 16 days after LPS injection. Normal SH-SY5Y cells or SH-SY5Y cells overexpressing α-synuclein were used to evaluate the distribution of α-synuclein and cholesterol in lysosomes and to assess the autophagic flux after miR-873 transfection or ABCA1 silencing. The inhibition of miR-873 significantly ameliorated the LPS-induced accumulation of α-synuclein and loss of dopaminergic neurons in the SN at the early stage. miR-873 mediated the inhibition of ABCA1 by LPS. miR-873 transfection or ABCA1 silencing increased the lysosomal cholesterol and α-synuclein levels, and decreased the autophagic flux. The knockdown of ABCA1 or A20, which are the downstream target genes of miR-873, exacerbated the damage to LPS-induced dopaminergic neurons. Conclusion and Implications. The results suggest that the inhibition of miR-873 may play a dual protective role by improving intracellular cholesterol homeostasis and neuroinflammation in PD. The therapeutic effects of the miR-873 sponge in PD may be due to the upregulation of ABCA1 and A20