Bone Morphogenetic Protein-4 Impairs Retinal Endothelial Cell Barrier, a Potential Role in Diabetic Retinopathy.

Bone Morphogenetic Protein 4 (BMP4) is a secreted growth factor of the Transforming Growth Factor beta (TGFß) superfamily. The goal of this study was to test whether BMP4 contributes to the pathogenesis of diabetic retinopathy (DR). Immunofluorescence of BMP4 and the vascular marker isolectin-B4 was conducted on retinal sections of diabetic and non-diabetic human and experimental mice. We used Akita mice as a model for type-1 diabetes. Proteins were extracted from the retina of postmortem human eyes and 6-month diabetic Akita mice and age-matched control. BMP4 levels were measured by Western blot (WB). Human retinal endothelial cells (HRECs) were used as an in vitro model. HRECs were treated with BMP4 (50 ng/mL) for 48 h. The levels of phospho-smad 1/5/9 and phospho-p38 were measured by WB. BMP4-treated and control HRECs were also immunostained with anti-Zo-1. We also used electric cell-substrate impedance sensing (ECIS) to calculate the transcellular electrical resistance (TER) under BMP4 treatment in the presence and absence of noggin (200 ng/mL), LDN193189 (200 nM), LDN212854 (200 nM) or inhibitors of vascular endothelial growth factor receptor 2 (VEGFR2; SU5416, 10 µM), p38 (SB202190, 10 µM), ERK (U0126, 10 µM) and ER stress (Phenylbutyric acid or PBA, 30 µmol/L). The impact of BMP4 on matrix metalloproteinases (MMP2 and MMP9) was also evaluated using specific ELISA kits. Immunofluorescence of human and mouse eyes showed increased BMP4 immunoreactivity, mainly localized in the retinal vessels of diabetic humans and mice compared to the control. Western blots of retinal proteins showed a significant increase in BMP4 expression in diabetic humans and mice compared to the control groups (p < 0.05). HRECs treated with BMP4 showed a marked increase in phospho-smad 1/5/9 (p = 0.039) and phospho-p38 (p = 0.013). Immunofluorescence of Zo-1 showed that BMP4-treated cells exhibited significant barrier disruption. ECIS also showed a marked decrease in TER of HRECs by BMP4 treatment compared to vehicle-treated HRECs (p < 0.001). Noggin, LDN193189, LDN212854, and inhibitors of p38 and VEGFR2 significantly mitigated the effects of BMP4 on the TER of HRECs. Our finding provides important insights regarding the role of BMP4 as a potential player in retinal endothelial cell dysfunction in diabetic retinopathy and could be a novel target to preserve the blood-retinal barrier during diabetes.

Anticancer Effects of the Corchorus olitorius Aqueous Extract and Its Bioactive Compounds on Human Cancer Cell Lines.

Corchorus olitorius is a common, leafy vegetable locally known as "Saluyot" in the Philippines. Several studies have reported on its various pharmacological properties, such as antioxidant, anti-inflammatory, analgesic, and anticancer properties. However, little is known about its effects on angiogenesis. This study aimed to evaluate the anticancer properties, such as the antiproliferative, anti-angiogenic, and antitumor activities, of the C. olitorius aqueous extract (CO) and its bioactive compounds, chlorogenic acid (CGA) and isoquercetin (IQ), against human melanoma (A-375), gastric cancer (AGS), and pancreatic cancer (SUIT-2), using in vitro and in ovo biological assays. The detection and quantification of CGA and IQ in CO were achieved using LC-MS/MS analysis. The antiproliferative, anti-angiogenic, and antitumor activities of CO, CGA, and IQ against A-375, AGS, and SUIT-2 cancer cell lines were evaluated using MTT and CAM assays. CGA and IQ were confirmed to be present in CO. CO, CGA, and IQ significantly inhibited the proliferation of A-375, AGS, and SUIT-2 cancer cells in a dose-dependent manner after 48 h of treatment. Tumor angiogenesis (hemoglobin levels) of A-375 and AGS tumors was significantly inhibited by CO, CGA, IQ, and a CGA-IQ combination. The growth of implanted A-375 and AGS tumors was significantly reduced by CO, CGA, IQ, and a CGA-IQ combination, as measured in tumor weight. Our investigation provides new evidence to show that CO has promising anticancer effects on various types of human cancer cells. CO and its compounds are potential nutraceutical products that could be used for cancer treatment.

Nanonutraceuticals: Anti-Cancer Activity and Improved Safety of Chemotherapy by Costunolide and Its Nanoformulation against Colon and Breast Cancer.

Costunolide (COS) is a sesquiterpene lactone with anticancer properties. The present study investigated the anticancer effects of COS against the human colon (HCT116) and breast (MDA-MB-231-Luc) cancer cell lines. Inhibition of cell lines viability and IC50 of COS were assessed via an MTT assay. Furthermore, the apoptotic rate was detected by assessment of Bcl2-associated X (Bax) and B-cell lymphoma 2 (Bcl2) protein levels by flow cytometry. Xenograft mice model of HCT116 and MDA-MB-231-Luc were carried out to determine the effect of COS and its nanoparticles (COS-NPs). The results demonstrated that COS inhibited the viability of HCT116 and MDA-MB-231-Luc cells, with a half maximal inhibitory concentration value (IC50) of 39.92 µM and 100.57 µM, respectively. COS significantly increased Bax and decreased Bcl2 levels in treated cells. COS and COS-NPs, in combination with doxorubicin (DOX), significantly decreased the tumor growth of HCT116 and MDA-MB-231-Luc implants in mice. Furthermore, oral administration of COS and COS-NPs significantly decreased the viable cells and increased necrotic/apoptotic cells of HCT116 and MDA-MB-231-Luc implants. Interestingly, both COS and COS-NPs protected the cardiac muscles against DOX's cardiotoxicity. The current results indicated the promising anticancer and cardiac muscles protection of COS and COS-NPs when administered with chemotherapy.

Novel Polyethylene Glycol-Conjugated Triazole Derivative with High Thyrointegrin αvß3 Affinity in Acute Myeloid Leukemia Management.

(1) Background: Acute myeloid leukemia (AML) accounts for up to one-third of more than 60,000 leukemia cases diagnosed annually in the U.S. Primary AML cells express membrane αvß3 integrin, which is associated with adverse prognosis and resistance to chemotherapies. A novel anticancer compound Polyethylene glycol-conjugated bi-TriAzole Tetraiodothyroacetic acid (P-bi-TAT) interacts with high affinity (Ki 0.3 nM) and specificity with the thyrointegrin αvß3. We evaluated P-bi-TAT activities in two different AML models representing monocytic and myelocytic forms of acute leukemia. (2) Methods and Results: The in vivo AML models were established prior to initiation of treatment protocols by grafting human leukemia cells in immunocompromised mice. IVIS imaging scans revealed that leukemic colonies were extensively established throughout the bone marrow, liver, and lung of the untreated animals. In animals treated with P-bi-TAT at daily doses ranging from 1-10 mg/kg, subcutaneously for 2-3 weeks, IVIS imaging scans revealed 95% reduction in bone marrow colonies and leukemic colonies in liver and lung. Also, the leukemic cells were not detected in bone marrow samples of P-bi-TAT-treated animals. The anti-neoplastic effect of P-bi-TAT administration on leukemic cells was associated with marked inhibition of NF-κB activity. We conclude that experimental P-bi-TAT therapy in vivo appears extraordinarily effective against the two forms of human AML models in mice. Because the P-bi-TAT molecular target, thyrointegrin αvß3, is consistently expressed in many, if not all, clinical AML samples, P-bi-TAT-based therapy seems to have significant clinical potential in treating most AML sub-types. Hence, P-bi-TAT represents a promising targeted therapeutic agent for AML patients.

In vitro differentiation of human bone marrow stromal cells into neural precursor cells using small molecules.

BACKGROUND: Neurogenic differentiation of human marrow stromal stem cells (hMSCs) into neural precursor cells (NPCs) offers new hope in many neurological diseases. Stromal cells can be differentiated into NPCs using small molecules acting as chemical inducers. The aim of this study is to formulate an efficient, direct, fast and safe protocol to differentiate hMSCs into NPCs using different inducers: b-mercaptoethanol (BME), triiodothyronine (T3), and curcumin (CUR). NEW METHOD: hMSCs were subjected to either 1 mM BME, 0.5 µM T3, or 5 µM CUR. Neurogenic differentiation was determined by assessing the protein expression of PAX6, SOX2, DLX2, and GAP-43 with flow cytometry and immunofluorescence, along with Nissl staining of differentiated cells. RESULTS AND COMPARISON WITH EXISTING METHOD: It was revealed that T3 and CUR are 70-80% better than BME in terms of efficiency and safety, and surprisingly BME was a good promoting factor for cell preconditioning with limited effects on neural trans-differentiation related to its toxic effects on cell viability. CONCLUSION: Reprogramming of bone marrow stromal cells into neural cells gives hope for treating different neurological disorders. Our study shows that T3 and CUR were effective in generation of NPCs from hMSCs with preservation of cell viability. BME was a good promoting factor for cell preconditioning with limited effects on neural transdifferentiation related to its toxic effects on cell viability.

Nano-Targeting of Thyrointegrin αvß3 Receptor in Solid Tumors and Impact on Radiosensitization.

Tetraiodothyroacetic acid is a ligand of thyrointegrin αvß3, a protein that is highly expressed in various solid tumors and surrounding neovascular regions. Its nano derivative, Nano-diamino-tetrac (NDAT), has anticancer properties in preclinical models, enhances radiosensitivity, and inhibits cancer cell growth in vitro after X-ray irradiation. Using a novel experimental system developed to deliver accurate radiation dose to tumors under sterile conditions, this study establishes NDAT's radiosensitizing effect in SUIT-2 pancreatic cancer and H1299 non-small cell lung carcinoma xenografts in athymic mice for tumor-targeted radiation. In this work, low-melting-point Lipowitz alloy was used to shield normal organs and allow accurate tumor-targeted irradiation. Over a three-week period, mice with SUIT-2 xenografts received daily NDAT treatment at different doses (0, 1, 3, or 10 mg/kg body weight) and tumor-targeted irradiation (1 or 5 Gy). Validation was performed with a test dose of 30 Gy to mice bearing SUIT-2 xenografts and resulted in more than 80% reduction in tumor weight, compared to nonirradiated tumor weight. The results of this work showed that NDAT had a radiosensitizing effect in a dose-dependent manner in decreasing tumor growth and viability. An enhanced anticancer effect of NDAT (1 mg/kg body weight) was observed in mice with H1299 xenografts receiving 5 Gy tumor-targeted irradiation, indicated by decreased tumor weight and increased necrosis, compared to nonirradiated tumors. This technique demonstrated accurate tumor-targeted irradiation with new shielding methodology, and combined with thyrointegrin antagonist NDAT treatment, showed anticancer efficacy in pancreatic cancer and non-small cell lung carcinoma.

New Thyrointegrin αvß3 Antagonist with a Scalable Synthesis, Brain Penetration, and Potent Activity against Glioblastoma Multiforme.

We have previously reported that the αvß3 inhibitor P-bi-TAT, a bifunctional version of the thyroid hormone metabolite tetraiodothyroacetic acid (tetrac) conjugated to polyethylene glycol (PEG) MW 4000, has excellent efficacy in a glioblastoma multiforme (GBM) mouse model. However, bioanalysis problems due to PEG polydispersity and large-scale synthesis issues led to a search for new molecules, culminating in the discovery of fb-PMT, a conjugate of tetrac and monodisperse PEG36, with a lipophilic 4-fluorobenzyl group at the opposite end of the PEG chain. fb-PMT reduces GBM tumor growth and viability by up to 98%, is suitable for large-scale synthesis, and is amenable to bioanalysis using mass spectrometry-based detection. We also showed that changes in lipophilicity at the opposite end of the PEG chain from the active tetrac component affected the proton NMR chemical shift of the tetrac moiety in D20 and brain levels of the compound after subcutaneous dosing.

Sulfated non-anticoagulant low molecular weight heparin in the prevention of cancer and non-cancer associated thrombosis without compromising hemostasis.

INTRODUCTION: Cancer-associated thrombosis (CAT) accounts for about 20% of all cases of Venous Thromboembolism (VTE). Tissue factor (TF) is documented to be highly expressed on cancer cells and pathological angiogenic endothelial cells. Here, we used a novel oxidized sulfated ultra-LMWH, S-NACH, which is devoid of anti-factor Xa and IIa activities with limited to no systemic anticoagulant effects. This sulfated form has enhanced binding to vascular endothelial cells (EC) and releases and potentiates the action of tissue factor pathway inhibitor (TFPI). S-NACH binds with high affinity to EC, releases and binds to EC TFPI, and promotes vascular antithrombotic effect with limited to no risk of bleeding complications. MATERIALS AND METHODS: We investigated the effects of S-NACH on clot kinetics in vitro and in vivo. Also, we investigated the effects of S-NACH on CAT mediated by human acute leukemia cells (K562) and human pancreatic cancer cells (SUIT2). RESULTS: S-NACH was associated with ~3-fold increase of TFPI 2 levels within 3 h. Also, S-NACH reversed the hypercoagulability state that is associated with cancer cells in vitro. In vivo, S-NACH at 20 mg/kg subcutaneously (SC) had no effect on bleeding time compared to both tinzaparin and enoxaparin at 5 mg/kg SC. S-NACH did not show any anti-IIa or anti-Xa activities in comparison to tinzaparin and enoxaparin (p < 0.001). CONCLUSION: Data suggest the importance of S-NACH through its EC binding, EC TFPI release and its interaction with TFPI in enhancing its activity in the prevention of cancer and non-cancer associated thrombosis with limited to no bleeding complications.

Targeting Thyrointegrin αvß3 Using Fluorobenzyl Polyethylene Glycol Conjugated Tetraiodothyroacetic Acid (NP751) in Acute Myeloid Leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is associated with poor long-term survival, even with newer therapeutic agents. Here, we show the results of our preclinical study, in which we evaluated the efficacy of a new thyrointegrin αvß3 antagonist, named fluorobenzyl polyethylene glycol conjugated tetraiodothyroacetic acid (fb-PMT). METHODS AND RESULTS: fb-PMT (NP751) is a potent αvß3 antagonist of molecular weight of 2,478.9 Da. it represents a conjugate of tetraiodothyroacetic acid (tetrac) and monodisperse polyethylene glycol (PEG36), with a 4-fluorobenzyl group capping the other end of the PEG. fb-PMT effectively suppresses the malignant growth of human acute myeloid leukemia (AML) after successful engraftment in transgenic NSG-S xenograft mouse models of either established human AML cell line or primary AML cells. Daily treatment with fb-PMT (1-10 mg/kg body weight) subcutaneously (s.c.) for 3-4 weeks was associated with marked regression of leukemogenesis and extended survival in both models. The efficiency of the fb-PMT therapy was verified using in vivo imaging system (IVIS) imaging, flow cytometry, and histopathological examination to monitor the engraftment of leukemic cells in the bone marrow and other organs. fb-PMT therapy for 3-4 weeks at 3 and 10 mg/kg daily doses exhibited significant reduction (p < 0.0001) of leukemic cell burden of 74% and >95%, respectively. All fb-PMT-treated mice in the 10 mg/kg treatment arm successfully maintained remission after discontinuing the daily treatment. Comprehensive fb-PMT safety assessments demonstrated excellent safety and tolerability at multiple folds above the anticipated human therapeutic doses. Lastly, our genome-wide microarray screens demonstrated that fb-PMT works through the molecular interference mechanism with multiple signaling pathways contributing to growth and survival of leukemic cells. CONCLUSION: Our preclinical findings of the potent anticancer activities of fb-PMT and its favorable safety profiles warrant its clinical investigation for the effective and safe management of AML.

A New Eucalyptol-Rich Lavender (Lavandula stoechas L.) Essential Oil: Emerging Potential for Therapy against Inflammation and Cancer.

BACKGROUND/AIM: natural products are a potential source for drug discovery and development of cancer chemoprevention. Considering that drugs currently available for the treatment of inflammatory and cancer conditions show undesirable side effects, this research was designed to evaluate, for the first time, the in vitro anticancer activity of Algerian Lavandula stoechas essential oil (LSEO) against different cancer cell lines, as well as its in vitro and in vivo topical and acute anti-inflammatory properties. MATERIALS AND METHODS: the LSEO was extracted by steam distillation, and chemical composition analysis was performed using gas chromatography. The main compounds identified in LSEO were oxygenated monoterpenes, such as 1,8-Cineole (61.36%). LSEO exhibited a potent anti-inflammatory activity using the xylene-induced mouse ear edema model. RESULTS: LSEO (200 and 20 mg/kg) was able to significantly reduce (p < 0.05) the carrageenan-induced paw edema with a similar effect to that observed for the positive control. Topical application of LSEO at doses of 82 and 410 mg/kg significantly reduced acute ear edema in 51.4% and 80.1% of the mice, respectively. Histological analysis confirmed that LSEO inhibited the skin inflammatory response. Moreover, LSEO was tested for its antitumor activity against different cancer cell lines. LSEO was found to be significantly active against human gastric adenocarcinoma (AGS), Melanoma MV3, and breast carcinoma MDA-MB-231 cells, with median inhibitory concentration (IC50) values of 0.035 ± 0.018, 0.06 ± 0.022 and 0.259 ± 0.089 µL/mL, respectively. Altogether, these results open a new field of investigation into the characterization of the molecules involved in anti-proliferative processes. CONCLUSION: We suggest that LSEO, with 1,8-Cineole as the major active component, is a promising candidate for use in skin care products with anti-inflammatory and anticancer properties. The results of this study may provide an experimental basis for further systematic research, rational development, and clinical utilization of lavender resources.

Senescent Colon and Breast Cancer Cells Induced by Doxorubicin Exhibit Enhanced Sensitivity to Curcumin, Caffeine, and Thymoquinone.

Cellular senescence is a process of physiological growth arrest that can be induced by intrinsic or extrinsic stress signals. Some cancer therapies are associated with senescence of cancer cells with a typical cell cycle arrest. Doxorubicin (Dox) induces senescence by a p53-dependent pathway and telomere dysfunction of numerous cancers. However, cellular senescence induces suppression in proliferation activity, and these cells will remain metabolically active and play an important role in tumor relapse and development of drug resistance. In the current study, we investigated the apoptotic effect of curcumin (Cur), caffeine (Caff), and thymoquinone (TQ) on senescent colon cancer HCT116 and breast cancer MCF7 cell lines treated with Dox. Results showed typical senescence markers including decreased bromodeoxyuridine incorporation, increased accumulation of senescence-associated ß-galactosidase (SA-ß-gal), cell cycle arrest, and upregulation of p53, P-p53, and p21 proteins. Annexin-V analysis by flow cytometry revealed 2- to 6-fold increases in annexin-V-positive cells in Dox-treated MCF7 and HCT116 cells by Cur (15 µM), Caff (10 mM), and TQ (50 µM; P < .001). In comparison between proliferative and senescent of either HCT116 or MCF7 cells, Caff at 15 mM and TQ at 25 µM induced significant increases in apoptosis of Dox-treated cells compared with proliferative cells (P < .001). Data revealed that Cur, Caff, and TQ potentially induced apoptosis of both proliferative and senescent HCT116 and MCF7 cells. In vivo and clinical trials are of great importance to validate this result.

Current and Future Molecular Targets for Acute Myeloid Leukemia Therapy.

OPINION STATEMENT: Acute myeloid leukemia (AML) disease prognosis is poor and there is a high risk of chemo-resistant relapse for both young and old patients. Thus, there is a demand for alternative and target-specific drugs to improve the 5-year survival rate. Current treatment mainstays include chemotherapy, or mutation-specific targeting molecules including FLT3 inhibitors, IDH inhibitors, and monoclonal antibodies. Efforts to devise new, targeted therapy have included recent advances in methods for high-throughput genomic screening and the availability of computer-assisted techniques for the design of novel agents predicted to specifically inhibit mutant molecules involved in leukemogenesis. Crosstalk between the leukemia cells and the bone marrow microenvironment through cell surface molecules, such as the integrins αvß3 and αvß5, might influence drug response and AML progression. This review article focuses on current AML treatment options, new AML targeted therapies, the role of integrins in AML progression, and a potential therapeutic agent-integrin αvß3 antagonist.

Novel Targeted Nano-Parthenolide Molecule against NF-kB in Acute Myeloid Leukemia.

The targeted nano-encapsulation of anticancer drugs can improve drug delivery and the selective targeting of cancer cells. Nuclear factor kappa B (NF-kB) is a regulator for different biological responses, including cell proliferation and differentiation. In acute myeloid leukemia (AML), constitutive NF-κB has been detected in more than 50% of cases, enabling leukemic cells to resist apoptosis and stimulate uncontrolled proliferation. We evaluated NF-kB expression in bone marrow samples from 103 patients with AML using quantitative real time polymerase chain reaction (RT-PCR) and found that expression was increased in 80.5% (83 out 103) of these patients with AML in comparison to the control group. Furthermore, overexpressed transmembrane glycoprotein (CD44) on leukemic cells in comparison to normal cells is known to play an important role in leukemic cell engraftment and survival. We designed poly lactide co-glycolide (PLGA) nanoparticles conjugated with antiCD44 and encapsulating parthenolide (PTL), a nuclear factor kappa B (NF-kB) inhibitor, in order to improve the selectivity and targeting of leukemic cells and to spare normal cells. In vitro, in leukemic cell lines Kasumi-1, KG-1a, and THP-1, proliferation was decreased by 40% (** p < 0.01) with 5 µM PLGA-antiCD44-PTL nanoparticles in comparison to the same concentration of free PTL (~10%). The higher uptake of the nanoparticles by leukemic cells was confirmed with confocal microscopy. In conclusion, PLGA-antiCD44-PTL nanoparticles improved the bioavailability and selective targeting of leukemic cells, thus holding promise as a drug delivery system to improve the cure rate of AML.

Prognostic value of some inflammatory markers in patients with lymphoma.

Background: Lymphoma is a group of blood cell tumors which develop from lymphocytes. The main forms of lymphoma are Hodgkin lymphoma (HL) and non-HL (NHL). Cytokines may contribute to lymphoma and they are related to risk NHL and HL. Aim: Assessment of the serum level of certain inflammatory markers as complementary indicators to confirm diagnosis of lymphoma patients that may be subjected to more invasive biopsy methods. Method: The serum levels of interleukin (IL)-1ß (IL-1ß), IL-6, IL-10, tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1), granulocyte colony-stimulating factor (G-CSF), and eotaxin were assessed by Bio-Plex Pro assays in 81 lymphoma patients and 44 NHL and 37 HL patients before and after chemotherapy treatment as well as 20 healthy persons as a control group. Results: Lymphoma patients showed significantly raised marker levels before treatment and significantly reduced levels related to pre-treatment and controls of post-treatment for most of the markers. MCP-1 reported the highest diagnostic accuracy. G-CSF significantly raised pre-treatment and TNF-α. MCP-1 significantly increased in post treated HL compared with NHL. In order to distinguish HL from NHL, G-CSF reported the highest diagnostic accuracy. NHL patients reported complete remission (CR) and those who reported stable disease (SD) and progressive disease (PD) represented 25% and 38% respectively compared with 16% and 27% of HL patients, while partial remission (PR) of HL patients were 56% compared with 36% of NHL patients. Conclusion: Most of the markers were significantly increased in pre-treatment but significantly decreased post-treatment. However, it was not considerably enough to get better prognosis of the disease. Elevated serum levels of inflammatory markers correlate with disease severity and low benefit from treatment.

Current status and future direction in the management of malignant melanoma.

The incidence of malignant melanoma is increasing rapidly on a global scale. Although some types of melanoma, for example primary cutaneous melanoma, can be managed by surgery, metastatic melanoma cannot and it has a high mortality rate. Both oncogene and immune-targeted strategies have shown marked efficacy in some patients, but their effect on overall survival is still variable. Therefore, newer therapeutic approaches are needed. Fortunately, new advances in molecular medicine have led to an understanding of an individual patient's cancer at the genomic level. This information is now being used in all stages of cancer treatment including diagnosis, treatment selection, and treatment monitoring. This new strategy of personalized medicine may lead to marked shifts in immunotherapeutic treatment approaches such as individualized cancer vaccines and adoptive transfer of genetically modified T cells. This review provides an overview of recent approaches in cancer research and expected impact on the future of treatment for metastatic melanoma.

Nanoparticulate Tetrac Inhibits Growth and Vascularity of Glioblastoma Xenografts.

Thyroid hormone as L-thyroxine (T4) stimulates proliferation of glioma cells in vitro and medical induction of hypothyroidism slows clinical growth of glioblastoma multiforme (GBM). The proliferative action of T4 on glioma cells is initiated nongenomically at a cell surface receptor for thyroid hormone on the extracellular domain of integrin αvß3. Tetraiodothyroacetic acid (tetrac) is a thyroid hormone derivative that blocks T4 action at αvß3 and has anticancer and anti-angiogenic activity. Tetrac has been covalently bonded via a linker to a nanoparticle (Nanotetrac, Nano-diamino-tetrac, NDAT) that increases the potency of tetrac and broadens the anticancer properties of the drug. In the present studies of human GBM xenografts in immunodeficient mice, NDAT administered daily for 10 days subcutaneously as 1 mg tetrac equivalent/kg reduced tumor xenograft weight at animal sacrifice by 50%, compared to untreated control lesions (p < 0.01). Histopathological analysis of tumors revealed a 95% loss of the vascularity of treated tumors compared to controls at 10 days (p < 0.001), without intratumoral hemorrhage. Up to 80% of tumor cells were necrotic in various microscopic fields (p < 0.001 vs. control tumors), an effect attributable to devascularization. There was substantial evidence of apoptosis in other fields (p < 0.001 vs. control tumors). Induction of apoptosis in cancer cells is a well-described quality of NDAT. In summary, systemic NDAT has been shown to be effective by multiple mechanisms in treatment of GBM xenografts.

Acute myeloid leukemia stem cell markers in prognosis and targeted therapy: potential impact of BMI-1, TIM-3 and CLL-1.

Acute myeloid leukemia (AML) patients show high relapse rates and some develop conventional chemotherapy resistance. Leukemia Stem Cells (LSCs) are the main player for AML relapses and drug resistance. LSCs might rely on the B-cell-specific Moloney murine leukemia virus integration site-1 (BMI-1) in promoting cellular proliferation and survival. Growth of LSCs in microenvironments that are deprived of nutrients leads to up-regulation of the signaling pathways during the progression of the disease, which may illustrate the sensitivity of LSCs to inhibitors of those signaling pathways as compared to normal cells. We analyzed the expression of LSC markers (CD34, CLL-1, TIM-3 and BMI-1) using quantitative RT-PCR in bone marrow samples of 40 AML patients of different FAB types (M1, M2, M3, M4, M5, and M7). We also studied the expression of these markers in 2 AML cell lines (Kasumi-1 and KG-1a) using flow cytometry and quantitative RT-PCR. The overexpression of TIM-3, CLL-1, and BMI-1 was markedly correlated with poor prognosis in these patients. Our in vitro findings demonstrate that targeting BMI-1, which markedly increased in the leukemic cells, was associated with marked decrease in leukemic burden. This study also presents results for blocking LSCs' surface markers CD44, CLL-1, and TIM-3. These markers may play an important role in elimination of AML. Our study indicates a correlation between the expression of markers TIM-3, CLL-1, and especially of BMI-1 and the aggressiveness of AML and thus the potential impact of prognosis and therapies that target LSCs on improving the cure rates.

Synthesis of MR-49, a deiodinated analog of tetraiodothyroacetic acid (tetrac), as a novel pro-angiogenesis modulator.

The tyrosine-based hormones 3,3',5-triiodo-l-thyronine (l-T3) and l-thyroxine (l-T4) that are produced by the thyroid gland control metabolic functions. Iodothyronine deiodinase enzymes convert l-T4 to l-T3, the form of thyroid hormone critical to genomic actions within cells and regulation of metabolism, and to reverse-l-T3, a hormone isoform that is largely inactive. We used tertiary amines in a study of deiodination based on derivatives of tetraiodothyroacetic acid (tetrac)-a naturally occurring derivative of l-T4-to mimic the action of the iodothyronine deiodinases and deiodination of the outer ring iodines. Deiodinated tetrac, MR-49, was found to be pro-angiogenic, with this activity exceeding that of l-T3 and l-T4 in a hemoglobin Matrigel® plug assay of angiogenesis. Tetrac is anti-angiogenic via several nongenomic pathways, and the present studies of MR-49 reveal the critical contribution of outer ring iodines to the angiogenic properties of thyroid hormone analogues, which may have utility as pro-angiogenic pharmaceuticals.