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

Comparative safety, pharmacokinetics, and off-target assessment of 1,1-bis(3'-indolyl)-1-(p-chlorophenyl) methane in mouse and dog: implications for therapeutic development

The modified phytochemical derivative, 1,1-bis(3'-indolyl)-1-(p-chlorophenyl) methane (C-DIM12), has been identified as a potential therapeutic platform based on its capacity to improve disease outcomes in models of neurodegeneration and cancer. However, comprehensive safety studies investigating pathology and off-target binding have not been conducted. To address this, we administered C-DIM12 orogastrically to outbred male CD-1 mice for 7 days (50 mg/kg/day, 200 mg/kg/day, and 300 mg/kg/day) and investigated changes in hematology, clinical chemistry, and whole-body tissue pathology. We also delivered a single dose of C-DIM12 (1 mg/kg, 5 mg/kg, 25 mg/kg, 100 mg/kg, 300 mg/kg, 1,000 mg/kg) orogastrically to male and female beagle dogs and investigated hematology and clinical chemistry, as well as plasma pharmacokinetics over 48-h. Consecutive in-vitro off-target binding through inhibition was performed with 10 μM C-DIM12 against 68 targets in tandem with predictive off-target structural binding capacity. These data show that the highest dose C-DIM12 administered in each species caused modest liver pathology in mouse and dog, whereas lower doses were unremarkable. Off-target screening and predictive modeling of C-DIM12 show inhibition of serine/threonine kinases, calcium signaling, G-protein coupled receptors, extracellular matrix degradation, and vascular and transcriptional regulation pathways. Collectively, these data demonstrate that low doses of C-DIM12 do not induce pathology and are capable of modulating targets relevant to neurodegeneration and cancer.

Stx2 Induces Differential Gene Expression and Disturbs Circadian Rhythm Genes in the Proximal Tubule

Shiga toxin-producing Escherichia coli (STEC) causes proximal tubular defects in the kidney. However, factors altered by Shiga toxin (Stx) within the proximal tubules are yet to be shown. We determined Stx receptor Gb3 in murine and human kidneys and confirmed the receptor expression in the proximal tubules. Stx2-injected mouse kidney tissues and Stx2-treated human primary renal proximal tubular epithelial cell (RPTEC) were collected and microarray analysis was performed. We compared murine kidney and RPTEC arrays and selected common 58 genes that are differentially expressed vs. control (0 h, no toxin-treated). We found that the most highly expressed gene was GDF15, which may be involved in Stx2-induced weight loss. Genes associated with previously reported Stx2 activities such as src kinase Yes phosphorylation pathway activation, unfolded protein response (UPR) and ribotoxic stress response (RSR) showed differential expressions. Moreover, circadian clock genes were differentially expressed, suggesting Stx2-induced renal circadian rhythm disturbance. Circadian rhythm-regulated proximal tubular Na⁺-glucose transporter SGLT1 (SLC5A1) was down-regulated, indicating proximal tubular functional deterioration, and mice developed glucosuria confirming proximal tubular dysfunction. Stx2 alters gene expression in murine and human proximal tubules through known activities and newly investigated circadian rhythm disturbance, which may result in proximal tubular dysfunctions.

Expression of IFN-induced 2'-5'-oligoadenylate synthetases correlates with immune infiltration, revealing potential targets and new biomarkers for basal-like breast cancer prognosis

Triple-negative breast cancer has been classified as basal-like immune activated (BLIA), basal-like immune-suppressed (BLIS), and two other subtypes, suggesting potential immune therapeutic targets for basal-like breast cancer (BLBC). 2'-5'-Oligoadenylate synthetases (OASs), identified from differentially expressed genes (DEGs) between BLIA and BLIS breast cancers (GSE76124), are involved in antiviral activity induced by interferons. However, the association between the four OASs and prognosis or tumor-infiltrating immune cells (TIICs) remains unclear. Expression, survival data, and immune correlations for OASs in BLBC were assessed using bioinformatics tools. We found that OASs were highly expressed in BLIA breast cancer. Survival analysis suggested that high transcriptional levels of OASs were associated with better overall survival, relapse-free survival, and distant metastasis-free survival in patients with BLBC. Moreover, the prognostic value of OASs with respect to different clinicopathological factors, and especially according to lymph node metastasis, in patients with BLBC was further assessed. Our findings elucidated the expression, prognostic role, and effect of OASs in TIICs on BLBC, which might promote the development of OAS-targeted immunotherapy for BLBC.

Small-molecule compounds target paraptosis to improve cancer therapy

According to its different occurrence mechanism, programmed cell death (PCD) is divided into apoptosis, autophagy, necrosis, paraptosis and so on. Paraptosis is morphologically different from apoptosis and autophagy, which exhibit cytoplasmic vacuolation derived from the ER, independent of caspase, absence of apoptotic morphology. Recent researches have implied that a variety of small molecule compounds, such as celastrol, curcumin, can induce paraptosis-associated cell death as the reagent to enhance anti-cancer activity. A better understanding of paraptosis will lay the foundation to develop new therapeutic strategies to treat human cancers that make full use of small-molecule compounds.

Investigation of new indole derivatives of bovine serum albumin using spectroscopic and molecular docking techniques

We investigated the interaction of two derivatives of bis (indolyl) methane with bovine serum albumin (BSA) using spectroscopic and molecular docking calculations. Fluorescence quenching measurements revealed that the quenching mechanism was static. Fӧrster energy transfer measurements, synchronous fluorescence spectroscopy and docking studies demonstrated that both bis(indolyl)methanes bound to the Trp residues of BSA. The docking study confirmed that both bis(indolyl)methanes form hydrogen bonds and van der Waals interactions with BSA. Our molecular docking study indicated that the compounds are located within the binding pocket of subdomains IIB and IB of BSA. Fourier transform infrared spectroscopy demonstrated that both bis(indolyl)methane derivatives can interact with BSA and can affect the secondary structure of BSA.

Evaluation of self-emulsified DIM-14 in dogs for oral bioavailability and in Nu/nu mice bearing stem cell lung tumor models for anticancer activity

3, 3-Diindolylmethane-14 (DIM-14), a novel lipophilic derivative of DIM, has demonstrated anticancer activity in different types of cancers. However, poor solubility and low oral bioavailability of DIM-14 limit its translational benefits in vivo. This study was carried out to improve the oral bioavailability of DIM-14 via self-emulsifying drug (SED) delivery system in dogs and to evaluate pharmacodynamic characteristics of SED against H1650 stem cell tumor models. DIM-14 was incorporated into an oil, surfactant, and co-surfactant mixture using labrafil and tween-80 to obtain SED. SED were characterized by droplet size, polydispersitiy index (PDI), zeta potential, entrapment efficiency (EE), in vitro permeability and drug release (investigated with Caco-2 monolayers and dissolution apparatus respectively). Pharmacokinetic parameters in dogs were evaluated and analyzed using Winonlin. Anti-tumor activity was carried out in H1650 lung tumor model. Particle size of SED was between 230 and 246 nm and surface charge was negative and ranged from 26.50 to 28.69 mV. Entrapment efficiency of SED was 85%. Pharmacokinetic evaluation in dogs showed increased Cmax (39.18 ± 7.34 vs 21.68 ± 6.3 μg·dL-1), higher AUC0-t (34,481.34 ± 1125.46 vs 14,159.53 ± 702.20 μg·min·dL-1) and improved absorption with 3 times more bioavailability of SED compared to DIM-14 solution. SED showed ~30-59% tumor volume/weight reduction in H1650 tumor model compared to DIM-P solution. Our studies demonstrate the potential application of self-emulsifying drug delivery system (SEDDS), that enhances oral absorption of DIM-14 and increased anti-tumor activity against lung tumor models.

A novel bisindole-PBD conjugate causes DNA damage induced apoptosis via inhibition of DNA repair pathway

DNA damage response (DDR) that includes cell cycle check points, DNA repair, apoptosis, and senescence is intimately linked with cancer. It shields an organism against cancer development when genomic integrity fails. DNA repair pathways protect the cells from tumor progression caused as a result of DNA damage induced by irradiation or due to chemotherapeutic treatment. Many promising anticancer agents have been identified that target specific DNA repair pathways in response to DNA damage thereby leading to apoptosis. Here we identified a novel bisindole-PBD conjugate that possess potent anticancer activity in breast cancer cells. Further studies aimed at understanding the mechanism of action of the molecule showed its role in DNA damage induced apoptosis via inhibition of DNA repair pathway. Trypan blue and BrdU assay exhibited a dose-dependent effect. Single-stranded DNA damage was observed by COMET assay. In addition DNA damage induced ROS generation with simultaneous activation of ATM and ATR upon compound treatment was observed. Further downregulation of Bcl-XL and activation of Bax showed DNA damage induced apoptosis in MCF-7 and MDAMB-231 cells. In conclusion, it can be summarized that bisindole-PBD conjugate induces DNA damage in a dose dependent (2, 4, and 8 μM) manner by inhibiting the DNA repair genes.

EphA2 targeting pegylated nanocarrier drug delivery system for treatment of lung cancer

PURPOSE

Evaluation of tumor targeting pegylated EphA2 peptide coated nanoparticles (ENDDs) of a novel anticancer agent DIM-C-pPhC6H5 (DIM-P) and Docetaxel (DOC) and investigate its antitumor activity and potential for treatment of lung cancer.

METHODS

Nanoparticles were prepared with DIM-P and DOC (NDDs) using Nano-DeBEE. ENDDs were prepared by conjugating NDDs with 6His-PEG2K-EphA2 peptide and characterized for physicochemical properties, binding assay, cytotoxicity, cellular uptake studies, drug release and pharmacokinetic parameters. Anti-tumor activity of ENDDs was evaluated using a metastatic H1650 and orthotopic A549 tumor models in nude mice and tumor tissue were analyzed by RT-PCR and immunohistochemistry.

RESULTS

Particle size and entrapment efficiency of ENDDs were 197 ± 21 nm and 95 ± 2%. ENDDs showed 32.5 ± 3.5% more cellular uptake than NDDs in tumor cells. ENDDs showed 23 ± 3% and 26 ± 4% more tumor reduction compared to NDDs in metastatic and orthotopic tumor models, respectively. In-vivo imaging studies using the Care stream MX FX Pro system showed (p < 0.001) 40-60 fold higher flux for ENDDs compared to NDDs at tumor site.

CONCLUSIONS

The results emanating from these studies demonstrate anti-cancer potential of DIM-P and the role of ENDDs as effective tumor targeting drug delivery systems for lung cancer treatment.

Targeting NR4A1 (TR3) in cancer cells and tumors

INTRODUCTION

Nuclear receptor 4A1(NR4A1) (testicular receptor 3 (TR3), nuclear hormone receptor (Nur)77) is a member of the nuclear receptor superfamily of transcription factors and is highly expressed in multiple tumor types. RNA interference studies indicate that NR4A1 exhibits growth-promoting, angiogenic and prosurvival activity in most cancers.

AREAS COVERED

Studies on several apoptosis-inducing agents that activate nuclear export of NR4A1, which subsequently forms a mitochondrial NR4A1-bcl-2 complex that induces the intrinsic pathway for apoptosis are discussed. Cytosporone B and related compounds that induce NR4A1-dependent apoptosis in cancer cells through both modulation of nuclear NR4A1 and nuclear export are discussed. A relatively new class of diindolylmethane analogs (C-DIMs) including 1,1-bis(3'-indolyl)-1-(p-methoxyphenyl)methane (DIM-C-pPhOCH(3)) (NR4A1 activator) and 1,1-bis(3'-indolyl)-1-(p-hydroxyphenyl)methane (DIM-C-pPhOH) (NR4A1 deactivator) are discussed in more detail. These anticancer drugs (C-DIMs) act strictly through nuclear NR4A1 and induce apoptosis in cancer cells and tumors.

EXPERT OPINION

It is clear that NR4A1 plays an important pro-oncogenic role in cancer cells and tumors, and there is increasing evidence that this receptor can be targeted by anticancer drugs that induce cell death via NR4A1-dependent and -independent pathways. Since many of these compounds exhibit relatively low toxicity, they represent an important class of mechanism-based anticancer drugs with excellent potential for clinical applications.

Characterization of variant diphtheria toxin-interleukin-3 fusion protein, DTIL3K116W, for phase I clinical trials

We have produced clinical grade of DTIL3K116W, a variant diphtheria toxin-interleukin-3 fusion protein, for treatment of acute myeloid leukemia. The product was filter sterilized, aseptically vialed, and stored at -80 degrees C. It was characterized by Coomassie-stained SDS-PAGE, endotoxin assay, cytotoxicity assay, sterility, mass spectroscopy, receptor binding affinity, ADP-ribosylation, inhibition of normal human CFU-GM, disulfide bond analysis, immunoblots, stability, size exclusion chromatography-HPLC, sequencing, and immunohistochemistry. Vialed product was sterile in 0.25 M NaCl/5 mM Tris, pH 7.9, and had a protein concentration of 1.08 mg/ml. Purity by SDS-PAGE was >99%. Aggregates by HPLC were <1%. Endotoxin levels were 0.296EU/mg. Peptide mapping and mass spectroscopy confirmed its composition and molecular weight. The vialed drug kept reactivity with anti-IL3 and DT antibodies. Potency study revealed a 48-h EC(50) of 0.5 pM on TF1/H-ras cell. Its binding properties were confirmed by competitive experiments showing IC(50) of 1.4 nM. ADP-ribosylation activity was equivalent to DTGM-CSF. Drug did not react with tested frozen human tissue sections by immunohistochemistry. There was no evidence of loss of solubility, proteolysis aggregation, or loss of potency over 6 months at -80 degrees C. Further, the drug was stable at 4 and 25 degrees C in the plastic syringe and administration tubing for 48 h.

Exploring bis-(indolyl)methane moiety as an alternative and innovative CAP group in the design of histone deacetylase (HDAC) inhibitors

In order to gather further knowledge about the structural requirements on histone deacetylase inhibitors (HDACi), starting from the schematic model of the common pharmacophore that characterizes this class of molecules (surface recognition CAP group-connection unit-linker region-Zinc Binding Group), we designed and synthesized a series of hydroxamic acids containing a bis-(indolyl)methane moiety. HDAC inhibition profile and antiproliferative activity were evaluated.

A Role for the PPARgamma in Cancer Therapy

In 1997, the first published reports highlighted PPARgamma as a novel cancer therapeutic target regulating differentiation of cancer cells. A subsequent flurry of papers described these activities more widely and fuelled further enthusiasm for differentiation therapy, as the ligands for the PPARgamma were seen as well tolerated and in several cases well-established in other therapeutic contexts. This initial enthusiasm and promise was somewhat tempered by contradictory findings in several murine cancer models and equivocal trial findings. As more understanding has emerged in recent years, a renaissance has occurred in targeting PPARgamma within the context of either chemoprevention or chemotherapy. This clarity has arisen in part through a clearer understanding of PPARgamma biology, how the receptor interacts with other proteins and signaling events, and the mechanisms that modulate its transcriptional actions. Equally greater translational understanding of this target has arisen from a clearer understanding of in vivo murine cancer models. Clinical exploitation will most likely require precise and quantifiable description of PPARgamma actions, and resolution of which targets are the most beneficial to target combined with an understanding of the mechanisms that limits its anticancer effectiveness.