Interferon regulatory factor-1 (IRF-1), a transcription factor and tumor suppressor involved in cell growth regulation and immune responses, has been shown to be induced by all-trans retinoic acid (ATRA). However, the factors controlling the cellular location and activity of IRF-1 are not well understood. In this study, we examined the expression of IRF-1 and its nuclear localization, DNA-binding activity, and target gene expression in human mammary epithelial MCF10A cells, a model of breast epithelial cell differentiation and carcinogenesis. Following initial treatment with ATRA, IRF-1 mRNA and protein were induced within 2 hrs, reached a peak (>30-fold induction) at 8 hrs, and declined afterwards. IRF-1 protein was predominantly cytoplasmic during this treatment. Although a second dose of ATRA or Am580 (a related retinoid selective for retinoic acid receptor-α [RARα]), given 16 hrs after the first dose, restimulated IRF-1 mRNA and protein levels to a similar level to that obtained by the first dose, IRF-1 was predominantly concentrated in the nucleus after restimulation. ATRA and Am580 also increased nuclear RARα, whereas retinoid X receptor-α (RXRa)—a dimerization partner for RARα, was localized to the nucleus upon second exposure to ATRA. However, ATRA and Am580 did not regulate the expression or activation of signal transducer and activator of transcription-1 (STAT-1), a transcription factor capable of inducing the expression of IRF-1, indicating an STAT-1–independent mechanism of regulation by ATRA and Am580. The increase in nuclear IRF-1 after retinoid restimulation was accompanied by enhanced binding to an IRF-E DNA response element, and elevated expression of an IRF-1 target gene, 2′,5′-oligoadenylate synthetase-2. The dual effect of retinoids in increasing IRF-1 mRNA and protein and in augmenting the nuclear localization of IRF-1 protein may be essential for maximizing the tumor suppressor activity and the immunosurveillance functions of IRF-1 in breast epithelial cells.
MiyamotoM, FujitaT, KimuraY, MaruyamaM, HaradaH, SudoY, MiyataT, TaniguchiT. Regulated expression of a gene encoding a nuclear factor, IRF-1, that specifically binds to IFN-beta gene regulatory elements. Cell54: 903–913, 1988.
9.
KimuraT, NakayamaK, PenningerJ, KitagawaM, HaradaH, MatsuyamaT, TanakaN, KamijoR, VilcekJ, MakTW, TaniguchiT. Involvement of the IRF-1 transcription factor in antiviral responses to interferons. Science264: 1921–1924, 1994.
10.
HaradaH, TaniguchiT, TanakaN. The role of interferon regulatory factors in the interferon system and cell growth control. Biochimie80: 641–650, 1998.
11.
RomeoG, FiorucciG, ChiantoreMV, PercarioZA, VannucchiS, AffabrisE. IRF-1 as a negative regulator of cell proliferation. J Interferon Cytokine Res22: 39–47, 2002.
12.
TanakaN, IshiharaM, KitagawaM, HaradaH, KimuraT, MatsuyamaT, LamphierMS, AizawaS, MakTW, TaniguchiT. Cellular commitment to oncogene-induced transformation or apoptosis is dependent on the transcription factor IRF-1. Cell77: 829–839, 1994.
13.
BoukerKB, SkaarTC, RigginsRB, HarburgerDS, FernandezDR, ZwartA, WangA, ClarkeR. Interferon regulatory factor-1 (IRF-1) exhibits tumor suppressor activities in breast cancer associated with caspase activation and induction of apoptosis. Carcinogenesis26: 1527–1535, 2005.
14.
ConnettJM, BadriL, GiordanoTJ, ConnettWC, DohertyGM. Interferon regulatory factor 1 (IRF-1) and IRF-2 expression in breast cancer tissue microarrays. J Interferon Cytokine Res25: 587–594, 2005.
15.
LuoXM, RossAC. Physiological and receptor-selective retinoids modulate interferon-gamma signaling by increasing the expression, nuclear localization, and functional activity of interferon regulatory factor-1. J Biol Chem280: 36228–36236, 2005.
16.
AranyI, WhiteheadWE, GrattendickKJ, EmberIA, TyringSK. Suppression of growth by all-trans retinoic acid requires prolonged induction of interferon regulatory factor 1 in cervical squamous carcinoma (SiHa) cells. Clin Diagn Lab Immunol9: 1102–1106, 2002.
17.
PelicanoL, LiF, SchindlerC, Chelbi-AlixMK. Retinoic acid enhances the expression of interferon-induced proteins: evidence for multiple mechanisms of action. Oncogene15: 2349–2359, 1997.
18.
PercarioZA, GiandomenicoV, FiorucciG, ChiantoreMV, VannucchiS, HiscottJ, AffabrisE, RomeoG. Retinoic acid is able to induce interferon regulatory factor 1 in squamous carcinoma cells via a STAT-1 independent signalling pathway. Cell Growth Differ10: 263–270, 1999.
19.
SouleHD, MaloneyTM, WolmanSR, PetersonWDJr., BrenzR, McGrathCM, RussoJ, PauleyRJ, JonesRF, BrooksSC. Isolation and characterization of a spontaneously immortalized human breast epithelial cell line, MCF-10. Cancer Res50: 6075–6086, 1990.
20.
FernandezSV, RussoIH, RussoJ. Estradiol and its metabolites 4-hydroxyestradiol and 2-hydroxyestradiol induce mutations in human breast epithelial cells. Int J Cancer118: 1862–1868, 2006.
21.
TanakaN, TaniguchiT. The interferon regulatory factors and oncogenesis. Semin Cancer Biol10: 73–81, 2000.
PengX, YunD, ChristovK. Breast cancer progression in MCF10A series of cell lines is associated with alterations in retinoic acid and retinoid X receptors and with differential response to retinoids. Int J Oncol25: 961–971, 2004.
24.
ChenQ, MaY, RossAC. Opposing cytokine-specific effects of all trans-retinoic acid on the activation and expression of signal transducer and activator of transcription (STAT)-1 in THP-1 cells. Immunology107: 199–208, 2002.
25.
WatanabeN, SakakibaraJ, HovanessianAG, TaniguchiT, FujitaT. Activation of IFN-beta element by IRF-1 requires a posttranslational event in addition to IRF-1 synthesis. Nucleic Acids Res19: 4421–4428, 1991.
26.
AllenbyG, BocquelMT, SaundersM, KazmerS, SpeckJ, RosenbergerM, LoveyA, KastnerP, GrippoJF, ChambonP, LevinAA. Retinoic acid receptors and retinoid X receptors: interactions with endogenous retinoic acids. Proc Natl Acad Sci U S A90: 30–34, 1993.
SaniBP, ZhangX, HillDL, ShealyYF. Retinyl methyl ether: binding to transport proteins and effect on transcriptional regulation. Biochem Biophys Res Commun223: 293–298, 1996.
29.
GianniM, Li CalziM, TeraoM, GuisoG, CacciaS, BarbuiT, RambaldiA, GarattiniE. AM580, a stable benzoic derivative of retinoic acid, has powerful and selective cyto-differentiating effects on acute promyelocytic leukemia cells. Blood87: 1520–1531, 1996.
30.
TaniguchiT, OgasawaraK, TakaokaA, TanakaN. IRF family of transcription factors as regulators of host defense. Annu Rev Immunol19: 623–655, 2001.
31.
Yu-LeeLY. Prolactin modulation of immune and inflammatory responses. Recent Prog Horm Res57: 435–455, 2002.
32.
Le StunffC, RotweinP. Growth hormone stimulates interferon regulatory factor-1 gene expression in the liver. Endocrinology139: 859–866, 1998.
33.
TaitL, SouleHD, RussoJ. Ultrastructural and immunocytochemical characterization of an immortalized human breast epithelial cell line, MCF-10. Cancer Res50: 6087–6094, 1990.
34.
Yu-LeeLY, HrachovyJA, StevensAM, SchwarzLA. Interferon-regulatory factor 1 is an immediate-early gene under transcriptional regulation by prolactin in Nb2 T cells. Mol Cell Biol10: 3087–3094, 1990.
35.
GilmourKC, ReichNC. Receptor to nucleus signaling by prolactin and interleukin 2 via activation of latent DNA-binding factors. Proc Natl Acad Sci U S A91: 6850–6854, 1994.
36.
ConnettJM, HuntSR, HickersonSM, WuSJ, DohertyGM. Localization of IFN-gamma-activated Stat1 and IFN regulatory factors 1 and 2 in breast cancer cells. J Interferon Cytokine Res23: 621–630, 2003.
37.
GorlichD, KutayU. Transport between the cell nucleus and the cytoplasm. Annu Rev Cell Dev Biol15: 607–660, 1999.
38.
FomerodM, OhnoM, YoshidaM, MattajIW. CRM1 is an export receptor for leucine-rich nuclear export signals. Cell90: 1051–1060, 1997.
39.
SchaperF, KirchhoffS, PosemG, KosterM, OumardA, SharfR, LeviBZ, HauserH. Functional domains of interferon regulatory factor I (IRF-1). Biochem J335: 147–157, 1998.
40.
LinR, HiscottJ. A role for casein kinase II phosphorylation in the regulation of IRF-1 transcriptional activity. Mol Cell Biochem191: 169–180, 1999.
41.
LinXF, ZhaoBX, ChenHZ, YeXF, YangCY, ZhouHY, ZhangMQ, LinSC, WuQ. RXRalpha acts as a carrier for TR3 nuclear export in a 9-cis retinoic acid-dependent manner in gastric cancer cells. J Cell Sci117: 5609–5621, 2004.
42.
YasminR, WilliamsRM, XuM, NoyN. Nuclear import of the retinoid X receptor, the vitamin D receptor, and their mutual heterodimer. J Biol Chem280: 40152–40160, 2005.
43.
LinR, YangL, ArguelloM, PenafuerteC, HiscottJ. A CRM1-dependent nuclear export pathway is involved in the regulation of IRF-5 subcellular localization. J Biol Chem280: 3088–3095, 2005.
44.
BarnesBJ, KellumMJ, PinderKE, FrisanchoJA, PithaPM. Interferon regulatory factor 5, a novel mediator of cell cycle arrest and cell death. Cancer Res63: 6424–6431, 2003.
45.
KumarKP, McBrideKM, WeaverBK, DingwallC, ReichNC. Regulated nuclear-cytoplasmic localization of interferon regulatory factor 3, a subunit of double-stranded RNA-activated factor 1. Mol Cell Biol20: 4159–4168, 2000.
46.
BeheraAK, KumarM, LockeyRF, MohapatraSS. 2′-5′ oligoadenylate synthetase plays a critical role in interferon-gamma inhibition of respiratory syncytial virus infection of human epithelial cells. J Biol Chem277: 25601–25608, 2002.
47.
MullanPB, HoseyAM, BuckleyNE, QuinnJE, KennedyRD, JohnstonPG, HarkinDP. The 2,5 oligoadenylate synthetase/RNaseL pathway is a novel effector of BRCA1- and interferon-gamma-mediated apoptosis. Oncogene24: 5492–5501, 2005.
48.
MalathiK, ParanjapeJM, GanapathiR, SilvermanRH. HPC1/RNA-SEL mediates apoptosis of prostate cancer cells treated with 2′,5′-oligoadenylates, topoisomerase 1 inhibitors, and tumor necrosis factor-related apoptosis-inducing ligand. Cancer Res64: 9144–9151, 2004.
