1,1-Bis(3'-indolyl)-1-(p-chlorophenyl)methane activates the orphan nuclear receptor Nurr1 and inhibits bladder cancer growth.

Nurr1 is an orphan nuclear receptor and a member of the nerve growth factor I-B subfamily of transcription factors with no known endogenous ligand or stimulator. We show, for the first time, evidence that Nurr1 is expressed in a panel of 11 human bladder cancer cell lines. A new class of methylene-substituted diindolylmethanes (C-DIM) were screened and 1,1-bis(3'-indolyl)-1-(p-chlorophenyl)methane (DIM-C-pPhCl) activated the ligand-binding domain of Nurr1.

ESE-1/EGR-1 pathway plays a role in tolfenamic acid-induced apoptosis in colorectal cancer cells.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are known to prevent colorectal tumorigenesis. Although antitumor effects of NSAIDs are mainly due to inhibition of cyclooxygenase activity, there is increasing evidence that cyclooxygenase-independent mechanisms may also play an important role. The early growth response-1 (EGR-1) gene is a member of the immediate-early gene family and has been identified as a tumor suppressor gene.

Role of SP transcription factors in hormone-dependent modulation of genes in MCF-7 breast cancer cells: microarray and RNA interference studies.

17beta-estradiol (E(2)) binds estrogen receptor alpha (ESR1) in MCF-7 cells and increases cell proliferation and survival through induction or repression of multiple genes. ESR1 interactions with DNA-bound specificity protein (SP) transcription factors is a nonclassical genomic estrogenic pathway and the role of SP transcription factors in mediating hormone-dependent activation or repression of genes in MCF-7 cells was investigated by microarrays and RNA interference. MCF-7 cells were transfected with a nonspecific oligonucleotide or a cocktail of small inhibitory RNAs (iSP), which knockdown SP1, SP3, and SP4 proteins, and treated with dimethylsulfoxide or 10 nM E(2) for 6 h.

Structure-dependent activation of endoplasmic reticulum stress-mediated apoptosis in pancreatic cancer by 1,1-bis(3'-indoly)-1-(p-substituted phenyl)methanes.

1,1-Bis(3'-indoly)-1-(p-substituted phenyl)methanes (C-DIM) exhibit structure-dependent activation of peroxisome proliferator-activated receptor gamma and nerve growth factor-induced Balpha (Nur77) and induce receptor-dependent and receptor-independent apoptosis in cancer cells and tumors. In this study, we investigated the activation of apoptosis in pancreatic cancer cells by p-bromo (DIM-C-pPhBr) and p-fluoro (DIM-C-pPhF) and structurally related analogues that do not activate either peroxisome proliferator-activated receptor gamma or Nur77. The ortho, meta, and para-bromo and -fluoro isomers all activated endoplasmic reticulum (ER) stress-dependent apoptosis in pancreatic cancer cells; however, methylation of the indole N group significantly decreased activity, suggesting that a free N was important for activation of ER stress.

Suppression of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced nitric-oxide synthase 2 expression in astrocytes by a novel diindolylmethane analog protects striatal neurons against apoptosis.

The progressive debilitation of motor functions in Parkinson's disease (PD) results from degeneration of dopaminergic neurons within the substantia nigra pars compacta of the midbrain. Long-term inflammatory activation of microglia and astrocytes plays a central role in the progression of PD and is characterized by activation of the nuclear factor-kappaB (NF-kappaB) signaling cascade and subsequent overproduction of inflammatory cytokines and nitric oxide (NO). Suppression of this neuroinflammatory phenotype has received considerable attention as a potential target for chemotherapy, but there are no currently approved drugs that sufficiently address this problem.

Non-classical genomic estrogen receptor (ER)/specificity protein and ER/activating protein-1 signaling pathways.

17beta-estradiol binds to the estrogen receptor (ER) to activate gene expression or repression and this involves both genomic (nuclear) and non-genomic (extranuclear) pathways. Genomic pathways include the classical interactions of ligand-bound ER dimers with estrogen-responsive elements in target gene promoters. ER-dependent activation of gene expression also involves DNA-bound ER that subsequently interacts with other DNA-bound transcriptions factors and direct ER-transcription factor (protein-protein) interactions where ER does not bind promoter DNA.

5,5'-Dibromo-bis(3'-indolyl)methane induces Kruppel-like factor 4 and p21 in colon cancer cells.

Bis(3'-indolyl)methane (DIM) is a metabolite of the phytochemical indole-3-carbinol, and both compounds exhibit a broad spectrum of anticancer activities. We have developed a series of synthetic symmetrical ring-substituted DIM analogues, including 5,5'-dibromoDIM, which are more potent than DIM as inhibitors of cancer cell and tumor growth. In colon cancer cells, 5,5'-dibromoDIM decreased cell proliferation and inhibited G(0)-G(1)- to S-phase progression, and this was accompanied by induction of the cyclin-dependent kinase inhibitor p21 in HT-29 and RKO colon cancer cells.

In vivo profiling of estrogen receptor/specificity protein-dependent transactivation.

17beta-Estradiol (E2) activates the estrogen receptor (ER) through multiple genomic and nongenomic pathways in various tissues/organs. ERalpha/specificity protein-dependent activation of E2-responsive genes containing GC-rich promoters has been identified in breast and other cancer cell lines, and in this study, we describe transgenic animals overexpressing a transgene containing three tandem GC-rich sites linked to a minimal TATA or thymidine kinase promoter and a luciferase gene. Several mouse lines expressing the transgenes were characterized and, in line 15, E2 induced a 9-fold increase in luciferase activity in the female mouse uterus, and the synthetic estrogens bisphenol A and nonylphenol also induced uterine luciferase activity.

Curcumin decreases specificity protein expression in bladder cancer cells.

Curcumin is the active component of tumeric, and this polyphenolic compound has been extensively investigated as an anticancer drug that modulates multiple pathways and genes. In this study, 10 to 25 micromol/L curcumin inhibited 253JB-V and KU7 bladder cancer cell growth, and this was accompanied by induction of apoptosis and decreased expression of the proapoptotic protein survivin and the angiogenic proteins vascular endothelial growth factor (VEGF) and VEGF receptor 1 (VEGFR1). Because expression of survivin, VEGF, and VEGFR1 are dependent on specificity protein (Sp) transcription factors, we also investigated the effects of curcumin on Sp protein expression as an underlying mechanism for the apoptotic and antiangiogenic activity of this compound.

Cancer chemotherapy with indole-3-carbinol, bis(3'-indolyl)methane and synthetic analogs.

Indole-3-carbinol (I3C) conjugates are phytochemicals expressed in brassica vegetables and have been associated with the anticancer activities of vegetable consumption. I3C and its metabolite bis(3'-indolyl)methane (DIM) induce overlapping and unique responses in multiple cancer cell lines and tumors, and these include growth inhibition, apoptosis and antiangiogenic activities. The mechanisms of these responses are complex and dependent on cell context.

1,1-Bis(3'-indolyl)-1-(p-substituted phenyl)methanes inhibit colon cancer cell and tumor growth through activation of c-jun N-terminal kinase.

1,1-Bis(3'-indolyl)-1-(p-substituted phenyl)methanes (C-DIMs) activate the orphan receptors peroxisome proliferator-activated receptor gamma (PPARgamma) and Nur77 and induce receptor-dependent and -independent apoptotic pathways in colon and other cancer cells. Structure-activity studies show that the p-bromo (DIM-C-pPhBr) and p-fluoro (DIM-C-pPhF) analogs, which exhibit minimal activation of Nur77 and PPARgamma, induce expression of CCAAT/enhancer-binding protein homologous protein (CHOP/GADD153) in colon cancer cells. Moreover, among a series of bromo and fluoro C-DIM analogs, their induction of CHOP was dependent on the position of the phenyl substituents (para >/= meta >/= ortho) and required a free indole group.

Absorption and biological activity of phytochemical-rich extracts from açai (Euterpe oleracea Mart.) pulp and oil in vitro.

Polyphenolic extracts from various fruits and vegetables have been shown to exert growth inhibitory effects in cell culture studies. Whereas individual polyphenolic compounds have been extensively evaluated, understanding of the biological activity of polyphenolic extracts from natural sources is limited and critical to the understanding of their potential effects on the human body. This study investigated the absorption and antiproliferative effects of phytochemical extracts from acai pulp and a polyphenolic-enriched acai oil obtained from the fruit pulp of the acai berry ( Euterpe oleracea Mart.

Ligand structure-dependent activation of estrogen receptor alpha/Sp by estrogens and xenoestrogens.

This study investigated the effects of E2, diethylstilbestrol (DES), antiestrogens, the phytoestrogen resveratrol, and the xenoestrogens octylphenol (OP), nonylphenol (NP), endosulfan, kepone, 2,3,4,5-tetrachlorobiphenyl-4-ol (HO-PCB-Cl(4)), bisphenol-A (BPA), and 2,2-bis-(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE) on induction of luciferase activity in breast cancer cells transfected with a construct (pSp1(3)) containing three tandem GC-rich Sp binding sites linked to luciferase and wild-type or variant ERalpha. The results showed that induction of luciferase activity was highly structure-dependent in both MCF-7 and MDA-MB-231 cells. Moreover, RNA interference assays using small inhibitory RNAs for Sp1, Sp3 and Sp4 also demonstrated structure-dependent differences in activation of ERalpha/Sp1, ERalpha/Sp3 and ERalpha/Sp4.

Structure-dependent inhibition of bladder and pancreatic cancer cell growth by 2-substituted glycyrrhetinic and ursolic acid derivatives.

Derivatives of oleanolic acid, ursolic acid and glycyrrhetinic acid substituted with electron-withdrawing groups at the 2-position in the A-ring which also contains a 1-en-3-one structure are potent inhibitors of cancer cell growth. In this study, we have compared the effects of several 2-substituted analogs of triterpenoid acid methyl esters derived from ursolic and glycyrrhetinic acid on proliferation of KU7 and 253JB-V bladder and Panc-1 and Panc-28 pancreatic cancer cells. The results show that the 2-cyano and 2-trifluoromethyl derivatives were the most active compounds.

1,1-bis(3'-indolyl)-1-(p-substituted phenyl)methanes decrease mitochondrial membrane potential and induce apoptosis in endometrial and other cancer cell lines.

1,1-Bis(3'-indolyl)-1-(p-substituted phenyl)methanes, containing p-t-butyl (DIM-C-pPhtBu) and phenyl (DIM-C-pPhC(6)H(5)) substituents, are peroxisome proliferator-activated receptor gamma (PPARgamma) agonists; however, DIM-C-pPhtBu-induced growth inhibition and cell death in human HEC1A endometrial cancer cells is PPARgamma-independent. DIM-C-pPhtBu decreased mitochondrial membrane potential (MMP) and promoted the release of cytochrome c and caspase activation and nuclear uptake of endonuclease G leading to apoptosis of HEC1A cells. DIM-C-pPhtBu specifically targeted the mitochondrial permeability transition pore complex (PTPC) because the DIM-C-pPhtBu-induced pro-apoptotic responses were inhibited by atractyloside (Atra), a compound that specifically interacts with the inner mitochondrial membrane adenine nucleotide transport (ANT) proteins.

Ligand-dependent interactions of the Ah receptor with coactivators in a mammalian two-hybrid assay.

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a high affinity ligand for the aryl hydrocarbon receptor (AhR). In this study, we investigated structure-dependent differences in activation of the AhR by a series of halogenated aromatic hydrocarbons. TCDD, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 3,3',4,4',5-pentachlorobiphenyl (PCB126) induced CYP1A1-dependent activities in HEK293 human embryonic kidney, Panc1 pancreatic cancer, and Hepa1c1c7 mouse hepatoma cell lines.

The peroxisome proliferator-activated receptor-gamma agonist 1,1-bis(3'-indolyl)-1-(p-trifluoromethylphenyl)methane suppresses manganese-induced production of nitric oxide in astrocytes and inhibits apoptosis in cocultured PC12 cells.

Reactive astrogliosis is a prominent neuropathologic feature of manganism, a neurodegenerative disorder caused by excessive accumulation of manganese (Mn) in the basal ganglia. Activation of astrocytes has been linked to neuronal injury in manganism resulting from overproduction of inflammatory mediators, including tumor necrosis factor-alpha (TNFalpha), interferon-gamma (IFNgamma), interleukin-1beta (IL-1beta), and nitric oxide (NO), but the signaling mechanisms by which Mn regulates these factors remain poorly understood. We previously reported that Mn enhances production of NO in activated astrocytes that promotes apoptosis in cocultured neuronal cells by a mechanism involving the transcription factor nuclear factor-kappaB (NF-kappaB) (Liu et al.

The oncogenic microRNA-27a targets genes that regulate specificity protein transcription factors and the G2-M checkpoint in MDA-MB-231 breast cancer cells.

There is evidence that specificity proteins (Sp), such as Sp1, Sp3, and Sp4, are overexpressed in tumors and contribute to the proliferative and angiogenic phenotype associated with cancer cells. Sp1, Sp3, and Sp4 are expressed in a panel of estrogen receptor (ER)-positive and ER-negative breast cancer cell lines, and we hypothesized that regulation of their expression may be due to microRNA-27a (miR-27a), which is also expressed in these cell lines and has been reported to regulate the zinc finger ZBTB10 gene, a putative Sp repressor. Transfection of ER-negative MDA-MB-231 breast cancer cells with antisense miR-27a (as-miR-27a) resulted in increased expression of ZBTB10 mRNA and decreased expression of Sp1, Sp3, and Sp4 at the mRNA and protein levels and also decreased activity in cells transfected with constructs containing Sp1 and Sp3 promoter inserts.

1,1-bis(3'-indolyl)-1-(p-substitutedphenyl)methanes induce apoptosis and inhibit renal cell carcinoma growth.

Purpose: 1,1-Bis(3'-indolyl)-1-(p-substitutedphenyl)methanes [methylene-substituted diindolylmethanes (C-DIM)] containing p-trifluoromethyl, p-t-butyl, and p-phenyl substituents activate peroxisome proliferator-activated receptor gamma (PPARgamma) and inhibit growth of several different cancer cell lines through receptor-dependent and receptor-independent pathways. The purpose of this study is to investigate the anticancer activity of these compounds in renal cell carcinoma.

Experimental Design: The anticancer activity of the p-t-butyl-substituted C-DIM compound (DIM-C-pPhtBu) was investigated in ACHN and 786-0 renal cell carcinoma cell lines and in an orthotopic model for renal carcinogenesis using ACHN cells injected directly into the kidney.

Vascular endothelial growth factor receptor-2 expression is down-regulated by 17beta-estradiol in MCF-7 breast cancer cells by estrogen receptor alpha/Sp proteins.

17beta-Estradiol (E2) induces and represses gene expression in breast cancer cells; however, the mechanisms of gene repression are not well understood. In this study, we show that E2 decreases vascular endothelial growth factor receptor 2 (VEGFR2) mRNA levels in MCF-7 cells, and this gene was used as a model for investigating pathways associated with E2-dependent gene repression. Deletion analysis of the VEGFR2 promoter indicates that the proximal GC-rich motifs at -58 and -44 are critical for the E2-dependent decreased response in MCF-7 cells.

Methyl 2-cyano-3,11-dioxo-18 beta-olean-1,12-dien-30-oate is a peroxisome proliferator-activated receptor-gamma agonist that induces receptor-independent apoptosis in LNCaP prostate cancer cells.

Methyl 2-cyano-3,11-dioxo-18beta-olean-1,12-diene-30-oate (beta-CDODA-Me) is a synthetic analog of the naturally occurring triterpenoid glycyrrhetinic acid, which contains a 2-cyano substituent in the A-ring. beta-CDODA-Me was a potent inhibitor of LNCaP prostate cancer cell growth (IC(50) approximately 1 muM) and activated peroxisome proliferator-activated receptor gamma (PPARgamma), whereas analogs without the cyano group were weakly cytotoxic and did not activate PPARgamma. beta-CDODA-Me induced p21 and p27, down-regulated cyclin D1 protein expression, and induced two other proapoptotic proteins, namely nonsteroidal anti-inflammatory drug-activated gene-1 and activating transcription factor-3.

1,1-bis(3'-indolyl)-1-(p-methoxyphenyl)methane activates Nur77-independent proapoptotic responses in colon cancer cells.

1,1-Bis(3'-indolyl)-1-(p-methoxyphenyl)methane (DIM-C-pPhOCH(3)) is a methylene-substituted diindolylmethane (C-DIM) analog that activates the orphan receptor nerve growth factor-induced-Balpha (NGFI-Balpha, Nur77). RNA interference studies with small inhibitory RNA for Nur77 demonstrate that DIM-C-pPhOCH(3) induces Nur77-dependent and -independent apoptosis, and this study has focused on delineating the Nur77-independent proapoptotic pathways induced by the C-DIM analog. DIM-C-pPhOCH(3) induced caspase-dependent apoptosis in RKO colon cancer cells through decreased mitochondrial membrane potential which is accompanied by increased mitochondrial bax/bcl-2 ratios and release of cytochrome c into the cytosol.

Role of specificity protein transcription factors in estrogen-induced gene expression in MCF-7 breast cancer cells.

Deletion analysis of several 17beta-estradiol (E(2))-responsive genes have identified GC-rich sites that are associated with hormone-induced transactivation in MCF-7 breast cancer cells. However, the role of individual specificity proteins (Sps) in mediating hormone-induced gene expression has not been unequivocally determined. In transient transfection studies using E(2)-responsive GC-rich promoters from the E(2)F1, carbamoylphosphate synthetase/aspartate transcarbamylase/dihydroorotase (CAD), and retinoic acid receptor alpha (RAR alpha) genes, RNA interference using small inhibitory RNAs for Sp1 (iSp1), Sp3 (iSp3), and Sp4 (iSp4) decreased both basal and E(2)-induced transactivation.

1,1-Bis(3'-indolyl)-1-(p-biphenyl)methane inhibits basal-like breast cancer growth in athymic nude mice.

Introduction: 1,1-Bis (3'-indolyl)-1-(p-biphenyl) methane (CDIM9) has been identified as a new peroxisome proliferator-activated receptor (PPAR)-gamma agonist that exhibits both receptor dependent and independent antitumor activities. CDIM9 has not previously been studied with respect to its effects against basal-like breast cancer. Our goal in the present study was to investigate the anti-basal-like breast tumor activity of CDIM9 in vitro and in vivo.

2-cyano-lup-1-en-3-oxo-20-oic acid, a cyano derivative of betulinic acid, activates peroxisome proliferator-activated receptor gamma in colon and pancreatic cancer cells.

Betulinic acid (BA) is a phytochemical triterpenoid acid from bark extracts and is cytotoxic to cancer cells and tumors. We modified the A-ring of BA to give a 2-cyano-1-en-3-one moiety and the effects of the 2-cyano-lup-1-en-3-oxo-20-oic acid (CN-BA), 2-cyano derivative of BA, and its methyl ester (CN-BA-Me) were investigated in colon and pancreatic cancer cells. Both CN-BA and CN-BA-Me were highly cytotoxic to Panc-28 pancreatic and SW480 colon cancer cells.