scholarly journals Orphan Receptor COUP-TF Is Required for Induction of Retinoic Acid Receptor β, Growth Inhibition, and Apoptosis by Retinoic Acid in Cancer Cells

2000 ◽  
Vol 20 (3) ◽  
pp. 957-970 ◽  
Author(s):  
Bingzhen Lin ◽  
Guo-quan Chen ◽  
Dongmei Xiao ◽  
Siva Kumar Kolluri ◽  
Xihua Cao ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Growth Inhibition ◽  
Cancer Cells ◽  
Retinoic Acid Receptor ◽  
Critical Role ◽  
Orphan Receptor ◽  
Dependent Manner ◽  
Anticancer Activities ◽  
Transient Transfection Assay ◽  
Acid Receptor

ABSTRACT Retinoic acid receptor β (RARβ) plays a critical role in mediating the anticancer effects of retinoids. Expression of RARβ is highly induced by retinoic acid (RA) through a RA response element (βRARE) that is activated by heterodimers of RARs and retinoid X receptors (RXRs). However, RARβ induction is often lost in cancer cells despite expression of RARs and RXRs. In this study, we provide evidence that orphan receptor COUP-TF is required for induction of RARβ expression, growth inhibition, and apoptosis by RA in cancer cells. Expression of COUP-TF correlates with RARβ induction in a variety of cancer cell lines. In addition, stable expression of COUP-TF in COUP-TF-negative cancer cells restores induction of RARβ expression, growth inhibition, and apoptosis by RA, whereas inhibition of COUP-TF by expression of COUP-TF antisense RNA represses the RA effects. In a transient transfection assay, COUP-TF strongly induced transcriptional activity of the RARβ promoter in a RA- and RARα-dependent manner. By mutation analysis, we demonstrate that the effect of COUP-TF requires its binding to a DR-8 element present in the RARβ promoter. The binding of COUP-TF to the DR-8 element synergistically increases the RA-dependent RARα transactivation function by enhancing the interaction of RARα with its coactivator CREB binding protein. These results demonstrate that COUP-TF, by serving as an accessory protein for RARα to induce RARβ expression, plays a critical role in regulating the anticancer activities of retinoids.

scholarly journals Unraveling the physiological roles of retinoic acid receptor-related orphan receptor α

2021 ◽  
Author(s):  
Ji Min Lee ◽  
Hyunkyung Kim ◽  
Sung Hee Baek
Keyword(s):  
Retinoic Acid ◽  
Molecular Mechanisms ◽  
Cancer Metabolism ◽  
Metabolic Diseases ◽  
Retinoic Acid Receptor ◽  
Critical Role ◽  
Orphan Receptor ◽  
Orphan Nuclear Receptor ◽  
Functional Link ◽  
Acid Receptor

AbstractRetinoic acid receptor-related orphan receptor-α (RORα) is a member of the orphan nuclear receptor family and functions as a transcriptional activator in response to circadian changes. Circadian rhythms are complex cellular mechanisms regulating diverse metabolic, inflammatory, and tumorigenic gene expression pathways that govern cyclic cellular physiology. Disruption of circadian regulators, including RORα, plays a critical role in tumorigenesis and facilitates the development of inflammatory hallmarks. Although RORα contributes to overall fitness among anticancer, anti-inflammatory, lipid homeostasis, and circadian clock mechanisms, the molecular mechanisms underlying the mode of transcriptional regulation by RORα remain unclear. Nonetheless, RORα has important implications for pharmacological prevention of cancer, inflammation, and metabolic diseases, and understanding context-dependent RORα regulation will provide an innovative approach for unraveling the functional link between cancer metabolism and rhythm changes.

scholarly journals Activation of Aromatase Expression by Retinoic Acid Receptor-related Orphan Receptor (ROR) α in Breast Cancer Cells

2009 ◽  
Vol 284 (26) ◽  
pp. 17711-17719 ◽  
Author(s):  
Hiroki Odawara ◽  
Toshiharu Iwasaki ◽  
Jun Horiguchi ◽  
Nana Rokutanda ◽  
Kazumi Hirooka ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Retinoic Acid ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Retinoic Acid Receptor ◽  
Orphan Receptor ◽  
Aromatase Expression ◽  
Acid Receptor

Promyelocytic Leukemia-Retinoic Acid Receptor α Binds and Prevents Activation of the Fas Receptor and Suppresses Fas-Mediated Apoptosis.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3976-3976
Author(s):  
Rong-Hua Tao ◽  
Zuzana Berkova ◽  
Jillian Wise ◽  
Urszula Daniluk ◽  
Felipe Samaniego
Keyword(s):  
Retinoic Acid ◽  
Cancer Cells ◽  
Retinoic Acid Receptor ◽  
Critical Role ◽  
Death Receptor ◽  
Promyelocytic Leukemia ◽  
Attractive Potential ◽  
Acid Receptor ◽  
Nb4 Cells ◽  
Retinoic Acid Receptor Α

Abstract Abstract 3976 Poster Board III-912 Fas plays a critical role in cell proliferation and in the selective killing of autoreactive lymphocytes and abnormal cells, including infected cells. To explain the common expression of Fas and the resistance to the Fas killing observed in some normal and cancer cells, we have screened cells for potential regulators of the Fas death receptor. By using mass spectroscopy analysis of Fas-associated proteins, we identified a group of peptides derived from promyelocytic leukemia (PML). PML enhances pro-apoptotic signaling, while the promyelocytic leukemia–retinoic acid receptor α (PMLRARα) activates pro-survival pathways. Given these opposing functions, we tested whether PMLRARα, which typically operates in a dominant-negative manner, blocks Fas-mediated apoptosis. Co-immunoprecipitation analysis demonstrated that PMLRARα interacts with Fas in acute promyelocytic leukemia (APL)-derived NB4 cells, U937-PR9 cells and in APL primary cells. The binding of PMLRARα to Fas was mapped to the B-box domain of PMLRARα. Flow cytometry analysis of propidium iodide-stained and Annexin-V-stained cells challenged with Fas ligand (FasL) or agonistic anti-Fas antibody (CH-11) indicated that the presence of PMLRARα was associated with blocked Fas-mediated apoptosis at early and late stages. The knockdown of PMLRARα with shRNA sensitized the NB4 cells to Fas-mediated apoptosis. Expression of PMLRARα in U937-PR9 cells prevented Fas-mediated cleavage of procaspase-8 and also prevented procaspase-8 from binding to the Fas complex upon stimulation with the agonistic anti-Fas antibody (CH-11). Further analysis indicated that PMLRARα bound to FLIPL/S and forms an apoptotic inhibitory complex with Fas, which prevents Fas activation. The data suggest that tissue-specific inhibitors of Fas such as PMLRARα block Fas-mediated apoptosis and thus can contribute to cancer development. Our results may provide an explanation for the long-known role of PMLRARα and PML in the regulation of Fas signaling, which we have shown to occur by direct regulation. We have identified an attractive potential target to the regulation of apoptosis at the PMLRARα-Fas and PML-Fas interfaces. By neutralizing the effect of death receptor inhibitors such as PMLRARα and other potential inhibitors, we can improve on the success of the many chemotherapeutic treatments that depend on activation of death receptors for effective elimination of cancer cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Hepatocyte nuclear factor-6 stimulates transcription of the alpha-fetoprotein gene and synergizes with the retinoic-acid-receptor-related orphan receptor alpha-4

2003 ◽  
Vol 369 (3) ◽  
pp. 583-591 ◽  
Author(s):  
Habib NACER-CHERIF ◽  
Brigitte BOIS-JOYEUX ◽  
Guy G. ROUSSEAU ◽  
Frédéric P. LEMAIGRE ◽  
Jean-Louis DANAN
Keyword(s):  
Retinoic Acid ◽  
Retinoic Acid Receptor ◽  
Orphan Receptor ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Acid Receptor ◽  
Splicing Isoforms ◽  
Liver Gene ◽  
A Site ◽  
Putative Binding Site

The rat α-fetoprotein (afp) gene is controlled by three enhancers whose function depends on their interaction with liver-enriched transcription factors. The afp enhancer III, located at −6kb, is composed of three regions that act in synergy. Two of these regions, called s1 and s2, contain a putative binding site for hepatocyte nuclear factor-6 (HNF-6). This factor is the prototype of the ONECUT family of cut-homoeodomain proteins and is a known regulator of liver gene expression in adults and during development. We show here that the two splicing isoforms of HNF-6 bind to a site in the s1 region and in the s2 region. The core sequence of the s1 site corresponds to none of the known HNF-6 binding sites. Nevertheless, the binding properties of the s1 site are identical with those of the s2 site and of previously characterized HNF-6 binding sequences. The HNF-6 consensus should therefore be rewritten as DRRTCVATND. Binding of HNF-6 to the s1 and s2 sites requires both the cut and the homoeo domains, is co-operative and induces DNA bending. HNF-6 strongly stimulates the activity of the afp enhancer III in transient transfection experiments. This effect requires the stereo-specific alignment of the two HNF-6 sites. Moreover, HNF-6 stimulates the enhancer in synergy with the retinoic-acid-receptor-related orphan receptor α (RORα), which binds to a neighbouring site in the s1 region. Thus expression of the afp gene requires functional interactions between HNF-6 molecules and between HNF-6 and RORα.

Sign in / Sign up

Export Citation Format

Share Document