RETRACTED: Godugu et al. Anti-Cancer Activities of Thyrointegrin αvß3 Antagonist Mono- and Bis-Triazole Tetraiodothyroacetic Acid Conjugated via Polyethylene Glycols in Glioblastoma. Cancers 2021, 13, 2780.

The journal retracts the article, "Anti-Cancer Activities of Thyrointegrin αvß3 Antagonist Mono- and Bis-Triazole Tetraiodothyroacetic Acid Conjugated via Polyethylene Glycols in Glioblastoma" [...].

Discovery of novel thyrointegrin αvß3 antagonist fb-PMT (NP751) in the management of human glioblastoma multiforme.

Background: Thyrointegrin αvß3 receptors are unique molecular cancer therapeutic targets because of their overexpression on cancer and rapidly dividing blood vessel cells compared and quiescent on normal cells. A macromolecule, TriAzole Tetraiodothyroacetic acid (TAT) conjugated to polyethylene glycol with a lipophilic 4-fluorobenyl group (fb-PMT and NP751), interacts with high affinity (0.21 nM) and specificity with the thyrointegrin αvß3 receptors on the cell surface without nuclear translocation in contrast to the non-polymer conjugated TAT. Methods: The following in vitro assays were carried out to evaluate NP751 including binding affinity to different integrins, transthyretin (TTR)-binding affinity, glioblastoma multiforme (GBM) cell adhesion, proliferation assays, nuclear translocations, chorioallantoic membrane model of angiogenesis, and microarray for molecular mechanisms. Additionally, in vivo studies were carried out to evaluate the anticancer efficacy of NP751, its biodistribution, and brain GBM tumor versus plasma levels kinetics. Results: NP751 demonstrated a broad spectrum of antiangiogenesis and anticancer efficacy in experimental models of angiogenesis and xenografts of human GBM cells. Tumor growth and cancer cells' viability were markedly decreased (by > 90%; P < .001) in fb-PMT-treated U87-luc or 3 different primary human GBM xenograft-bearing mice based on tumor in vivo imaging system (IVIS) imaging and histopathological examination, without relapse upon treatment discontinuation. Additionally, it effectively transports across the blood-brain barrier via its high-affinity binding to plasma TTR with high retention in brain tumors. NP751-induced effects on gene expression support the model of molecular interference at multiple key pathways essential for GBM tumor progression and vascularization. Conclusions: fb-PMT is a potent thyrointegrin αvß3 antagonist with potential impact on GBM tumor progression.

Correction: Block et al. Fluorinated Analogs of Organosulfur Compounds from Garlic (Allium sativum): Synthesis, Chemistry and Anti-Angiogenesis and Antithrombotic Studies. Molecules 2017, 22, 2081.

In the original publication [...].

Pharmacokinetics of fluorobenzyl polyethylene glycol conjugated tetraiodothyroacetic acid (NP751), a novel anticancer thyrointegrin αvß3 antagonist.

We have recently reported on the development of fb-PMT (NP751), a conjugate of the thyroid hormone metabolite tetraiodothyroacetic acid (tetrac) and monodisperse polyethylene glycol 36. It exhibited high affinity for thyrointegrin αvß3 receptor and potent anti-angiogenic and anticancer activity in vivo. The objective of the current study is to determine the pharmacokinetics (PK) of fb-PMT in experimental animals, such as mice, rats, and monkeys. NP751 was quantified using a propylene diamine-modified tetraiodothyroacetic acid (DAT) as an internal standard. The limit of quantification (LOQ) for fb-PMT was 1.5 ng/µL and the recovery efficiency was 93.9% with the developed method. The peak plasma concentration (Cmax) and the area under the curve (AUC) results at different doses in mice, rats and monkeys suggest that pharmacokinetics of NP751 is dose-dependent within the dose ranges administered. Results indicate that NP751 has comparable PK parameters that provides enough exposure as a molecularly tumor targeted molecule in multiple species and is a promising anticancer therapeutic.

Correction: Godugu et al. Nanoformulated Ajwa (Phoenix Dactylifera) Bioactive Compounds Improve the Safety of Doxorubicin without Compromising Its Anticancer Efficacy in Breast Cancer. Molecules 2020, 25, 2597.

In the original publication [...].

Correction: Godugu et al. Anti-Cancer Activities of Thyrointegrin αvß3 Antagonist Mono- and Bis-Triazole Tetraiodothyroacetic Acid Conjugated via Polyethylene Glycols in Glioblastoma. Cancers 2021, 13, 2780.

In the original publication [...].

Curcumin, thymoquinone, and 3, 3'-diindolylmethane combinations attenuate lung and liver cancers progression.

Cancer can develop due to abnormal cell proliferation in any body's cells, so there are over a hundred different types of cancer, each with its distinct behavior and response to treatment. Therefore, many studies have been conducted to slow cancer progression and find effective and safe therapies. Nutraceuticals have great attention for their anticancer potential. Therefore, the current study was conducted to investigate the anticancer effects of curcumin (Cur), thymoquinone (TQ), and 3, 3'-diindolylmethane (DIM) combinations on lung (A549) and liver (HepG2) cancer cell lines' progression. Results showed that triple (Cur + TQ + DIM) and double (Cur + TQ, Cur + DIM, and TQ + DIM) combinations of Cur, TQ, and DIM significantly increased apoptosis with elevation of caspase-3 protein levels. Also, these combinations exhibited significantly decreased cell proliferation, migration, colony formation activities, phosphatidylinositol 3-kinase (PI3K), and protein kinase B (AKT) protein levels with S phase reduction. Triple and double combinations of Cur, TQ, and DIM hindered tumor weight and angiogenesis of A549 and HepG2 implants in the chorioallantoic membrane model. Interestingly, Cur, TQ, and DIM combinations are considered promising for suppressing cancer progression via inhibiting tumor angiogenesis. Further preclinical and clinical investigations are warranted.

Edible Green Solvent for Optimized Catechins Extraction from Green Tea Leaves: Anti-Hypercholesterolemia.

Catechin polyphenols are the major bioactive ingredients in green tea with various human health benefits. Extraction of catechins from green tea (GTE) leaves at optimized standard conditions is still a challenging approach. An optimized, rapid, and economic extraction method is industrially needed. We hypothesized that certain extraction techniques in the presence of natural polymers and antioxidants might improve GTE catechin extraction yield and its biological activity. The effect of microwave (30-60 seconds irradiation in a typical kitchen microwave) assisted extraction (MAE) and ultrasonic assisted extraction (UAE) techniques were evaluated separately and in combination. To study the effect of the extraction solvent, nine edible green solvent combinations were investigated namely water, ascorbic acid, chitosan/ascorbic acid, carboxymethylcellulose /ascorbic acid, methylcellulose /ascorbic acid, chitosan/methylcellulose/ascorbic acid, methylcellulose, chitosan/acetic acid, and ethanol. The amounts of extracted catechins from green tea leaves were quantified with HPLC-UV. Data showed that the use of MAE & UAE technique was the optimal in producing a higher extraction yield of catechins. Chitosan/ascorbic acid was the optimized solvent with high extraction efficiencies of catechins. Studies in high fat diet fed animals demonstrated significant reduction of total cholesterol and LDL-C by GTE after 3 weeks of oral daily administration. In conclusion, efficient extraction, and stabilization of catechins from green tea leaves demonstrated a significant lowering of high fat diet-mediated elevation in blood cholesterol and LDL-C levels.

Anticancer Efficacy and Mechanisms of a Dual Targeting of Norepinephrine Transporter and Thyrointegrin αvß3 Antagonist in Neuroblastoma.

Background: In neuroendocrine tumors, the norepinephrine transporter (NET) is very active and has been exploited for diagnostic imaging purposes and/or therapy with localized radiotherapy. Integrin αvß3 is generously expressed by and/or activated on cancer cells, but not by nonmalignant cells. Purpose: In the present investigation, the anticancer efficacy of the dual targeting of norepinephrine transporter (NET), benzylguanidine (BG), and thyrointegrin αvß3 receptors antagonist triazole tetraiodothyroacetic acid (TAT) conjugated via the non-cleavable linker polyethylene glycol (P, PEG400) in the treatment of human neuroblastoma was evaluated. Experimental approach: The synthesized dual targeting compound, a novel new chemical entity named BG-P400-TAT, has purity > 98% and was formulated and tested in neuroblastoma models using neuroblastoma cell lines (SK-N-FI, SMS-KCN and SMS-KANR) implanted in SCID and NSG mice models. Key Results: BG-P400-TAT demonstrated significant (**P<0.01, ***P< 0.001) suppression of neuroblastoma tumor progression, growth, and viability in both mice models implanted with the neuroblastoma. The pharmacokinetic and biodistribution profile of BG-P400-TAT showed a significant increase in BG-P400-TAT levels in plasma and xenografts of NSG compared to SCID mice. Further our RNAseq genome-wide expression profiling experiments in neuroblastoma cell line SKNAS results showed that BG-P400-TAT treatment altered the signal transduction pathways, intracellular multiprotein complexes and Independent GSEA. Conclusion & Implications: BG-P400-TAT represents a potential lead candidate for the treatment of neuroblastoma and other neuroendocrine tumors.

Triazole Modified Tetraiodothyroacetic Acid Conjugated to Polyethylene Glycol, a Thyrointegrin αvß3 Antagonist as a Radio- and Chemo-Sensitizer in Pancreatic Cancer.

Thyroid hormone L thyroxine stimulates pancreatic carcinoma cell proliferation via thyrointegrin αvß3 receptors, and antagonist tetraiodothyroacetic acid (tetrac) inhibits cancer cell growth. Chemically modified bis-triazole-tetrac conjugated with polyethylene glycol (P-bi-TAT) has higher binding affinity to αvß3 receptors compared to tetrac. We investigated the antiproliferation effect of P-bi-TAT in pancreatic cancer cells (SUIT2) and its radio- and chemo-sensitizing roles in a mouse model of pancreatic cancer. P-bi-TAT treatment increased tumor-targeted radiation-induced cell death and decreased tumor size. P-bi-TAT acted as a chemo-sensitizer and enhanced the 5-fluorouracil (5FU) effect in decreasing pancreatic tumor weight compared to 5FU monotherapy. Withdrawal of treatment continued the tumor regression; however, the 5FU group showed tumor regrowth. The mechanisms of the anti-cancer activity of P-bi-TAT on SUIT2 cells were assessed by microarray experiments, and genome-wide profiling identified significant alterations of 1348 genes' expression. Both down-regulated and up-regulated transcripts suggest that a molecular interference at the signaling pathway-associated gene expression is the prevalent mode of P-bi-TAT anti-cancer activity. Our data indicate that non-cytotoxic P-bi-TAT is not only an anti-cancer agent but also a radio-sensitizer and chemo-sensitizer that acts on the extracellular domain of the cell surface αvß3 receptor.

Effects of Anticancer Agent P-bi-TAT on Gene Expression Link the Integrin Thyroid Hormone Receptor to Expression of Stemness and Energy Metabolism Genes in Cancer Cells.

Chemically modified forms of tetraiodothyroacetic acid (tetrac), an L-thyroxine derivative, have been shown to exert their anticancer activity at plasma membrane integrin αvß3 of tumor cells. Via a specific hormone receptor on the integrin, tetrac-based therapeutic agents modulate expression of genes relevant to cancer cell proliferation, survival and energy metabolism. P-bi-TAT, a novel bivalent tetrac-containing synthetic compound has anticancer activity in vitro and in vivo against glioblastoma multiforme (GBM) and other types of human cancers. In the current study, microarray analysis was carried out on a primary culture of human GBM cells exposed to P-bi-TAT (10-6 tetrac equivalent) for 24 h. P-bi-TAT significantly affected expression of a large panel of genes implicated in cancer cell stemness, growth, survival and angiogenesis. Recent interest elsewhere in ATP synthase as a target in GBM cells caused us to focus attention on expression of genes involved in energy metabolism. Significantly downregulated transcripts included multiple energy-metabolism-related genes: electron transport chain genes ATP5A1 (ATP synthase 1), ATP51, ATP5G2, COX6B1 (cytochrome c oxidase subunit 6B1), NDUFA8 (NADH dehydrogenase (ubiquinone) FA8), NDUFV2I and other NDUF genes. The NDUF and ATP genes are also relevant to control of oxidative phosphorylation and transcription. Qualitatively similar actions of P-bi-TAT on expression of subsets of energy-metabolism-linked genes were also detected in established human GBM and pancreatic cancer cell lines. In conclusion, acting at αvß3 integrin, P-bi-TAT caused downregulation in human cancer cells of expression of a large number of genes involved in electron transport and oxidative phosphorylation. These observations suggest that cell surface thyroid hormone receptors on αvß3 regulate expression of genes relevant to tumor cell stemness and energy metabolism.

In Vivo Clearance of Apoptotic Debris From Tumor Xenografts Exposed to Chemically Modified Tetrac: Is There a Role for Thyroid Hormone Analogues in Efferocytosis?

Apoptosis is induced in cancer cells and tumor xenografts by the thyroid hormone analogue tetraiodothyroacetic acid (tetrac) or chemically modified forms of tetrac. The effect is initiated at a hormone receptor on the extracellular domain of plasma membrane integrin αvß3. The tumor response to tetrac includes 80% reduction in size of glioblastoma xenograft in two weeks of treatment, with absence of residual apoptotic cancer cell debris; this is consistent with efferocytosis. The molecular basis for efferocytosis linked to tetrac is incompletely understood, but several factors are proposed to play roles. Tetrac-based anticancer agents are pro-apoptotic by multiple intrinsic and extrinsic pathways and differential effects on specific gene expression, e.g., downregulation of the X-linked inhibitor of apoptosis (XIAP) gene and upregulation of pro-apoptotic chemokine gene, CXCL10. Tetrac also enhances transcription of chemokine CXCR4, which is relevant to macrophage function. Tetrac may locally control the conformation of phagocyte plasma membrane integrin αvß3; this is a cell surface recognition system for apoptotic debris that contains phagocytosis signals. How tetrac may facilitate the catabolism of the engulfed apoptotic cell debris requires additional investigation.

Novel oral nano-hepatic targeted anti-PCSK9 in hypercholesterolemia.

Proprotein convertase subtilisin/kexin type 9 is a protease enzyme secreted by liver that downregulates hepatic low-density lipoprotein receptor (LDLR) by binding and chaperoning LDLR to lysosomes for degradation, causing hypercholesteremia. The development of anti-PCSK9 therapeutics attracted considerable attention for the management of cardiovascular disease risk. However, only subcutaneous injectable PCSK9 monoclonal antibodies have been FDA approved. Oral administration of small-molecule PCSK9 inhibitors has the potential to become a practical therapeutic option if achievable. In the present work, we used nanotechnological approaches to develop the first small oral molecule nano-hepatic targeted anti-PCSK9. Using high-throughput optimization and a series of evaluations, a stable water-dispersible 150-200 nm nano-encapsulated drug (named P-4) conjugated with hepatic targeting moiety was synthesized and characterized (named P-21). Pharmacodynamic (PD), pharmacokinetic (PK) and bioavailability studies were conducted using a high fat diet nutritionally induced hypercholesterolemia mouse model to evaluate the efficacy of P-21 as an anti-PCSK9 LDL-cholesterol lowering hepatic targeted nanodrug. The PD results demonstrate that P-21 in a dose-dependent manner is highly effective in lowering LDL-C by 50-90%. PK results show the maximum plasma concentration (Cmax) of P-4 was observed after 30 min of administration with 31% oral bioavailability and had a sustained longer half-life up to 24 h. In vivo safety studies in rats showed no apparent adverse effects, normal chemical biomarkers and normal histopathological findings in all P-21 treated groups at different escalating doses. Compared to the FDA-approved monoclonal antibodies, P-21 offers a more efficient, and practical treatment protocol for targeting uncontrolled hypercholesterolemia in reducing the risk of cardiovascular diseases. The present study introduced a nano-targeted drug delivery approaches for PCSK9/LDLR antagonist.

Effects of sevelamer carbonate versus calcium acetate on vascular calcification, inflammation, and endothelial dysfunction in chronic kidney disease.

Hyperphosphatemia is present in most patients with end-stage renal disease (ESRD) and has been associated with increased cardiovascular mortality. Phosphate binders (calcium-based and calcium free) are the mainstay pharmacologic treatment to lower phosphorus levels in patients with ESRD. We evaluated biochemical markers of vascular calcification, inflammation, and endothelial dysfunction in patients with chronic kidney disease (CKD) treated with sevelamer carbonate (SC) versus calcium acetate (CA). Fifty patients with CKD (stages 3 and 4) were enrolled and assigned to treatment with SC and CA for 12 weeks. At the end of the study the biomarkers of vascular calcification, inflammation, and endothelial dysfunction were analyzed. A significant increase in HDL-cholesterol was observed with SC but not with CA in patients with CKD. Treatment with SC reduced serum phosphate, calcium phosphate, and FGF-23 levels and there was no change with CA treatment. The inflammatory markers IL-8, IFN-γ, and TNFα decreased with response to both treatments. The levels of IL-6 significantly increased with CA treatment and no change was observed in the SC treatment group. SC showed favorable effects on anti-inflammatory and vascular calcification biomarkers compared to CA treatment in patients with CKD stages 3 and 4 with normal phosphorous values.

Norepinephrine transporter analog benzylguanidine-conjugated nanoparticles for the delivery of paclitaxel in neuroblastoma.

Aim: We previously synthesized a polyethylene glycol-based norepinephrine transporter-targeted agent, BG-P-TAT, which has a benzylguanidine and a triazolyl-tetrac group. This targeted conjugate showed suppression of neuroblastoma tumor progression. In this study we aimed to synthesize nanoparticles to encapsulate the chemotherapeutic agent paclitaxel for targeting neuroblastoma tumors by using benzylguanidine so that it can compete with norepinephrine for uptake by neuroendocrine cells. Methods: Biocompatible poly(lactide-co-glycolic acid)-polyethylene glycol was chosen to prepare targeted nanoparticles for safe delivery of the chemotherapy agent paclitaxel. Result: Paclitaxel concentration was 60% higher in neuroblastoma tumors of mice treated with paclitaxel encapsulated in targeted nanoparticles than with non-targeted nanoparticles. Conclusion: These findings support the targeted delivery of paclitaxel as a chemotherapeutic agent for neuroblastoma.

Thymoquinone and Costunolide Induce Apoptosis of Both Proliferative and Doxorubicin-Induced-Senescent Colon and Breast Cancer Cells.

Doxorubicin (Dox) induces senescence in numerous cancer cell types, but these senescent cancer cells relapse again if they are not eliminated. On this principle, we investigated the apoptotic effect of thymoquinone (TQ), the active ingredient of Nigella sativa seeds and costunolide (COS), the active ingredient of Costus speciosus, on the senescent colon (Sen-HCT116) and senescent breast (Sen-MCF7) cancer cell lines in reference to their corresponding proliferative cells to rapidly eliminate the senescent cancer cells. The senescence markers of Sen-HCT116 and Sen-MCF7 were determined by a significant decrease in bromodeoxyuridine (BrdU) incorporation and significant increases in SA-ß-gal, p53, and p21 levels. Then proliferative, Sen-HCT116, and Sen-MCF7 cells were subjected to either TQ (50 µM) or COS (30 µM), the Bcl2-associated X protein (Bax), B-cell lymphoma 2 (Bcl2), caspase 3 mRNA expression and its activity were established. Results revealed that TQ significantly increased the Bax/Bcl2 ratio in HCT116 + Dox5 + TQ, MCF7 + TQ, and MCF7 + Dox5 + TQ compared with their corresponding controls. COS significantly increased the Bax/Bcl2 ratio in HCT116 + Dox5 + TQ and MCF7 + Dox5 + TQ compared with their related controls. Also, TQ and COS were significantly increased caspase 3 activity and cell proliferation of Sen-HCT116 and Sen-MCF7. The data revealed a higher sensitivity of senescent cells to TQ or COS than their corresponding proliferative cells.

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.