An efficient human stem cells derived cardiotoxicity testing platform for testing oncotherapeutic analogues of quercetin and cinnamic acid.

Oncotherapeutics research is progressing at a rapid pace, however, not many drugs complete the successful clinical trial because of severe off-target toxicity to cardiomyocytes which ultimately leads to cardiac dysfunction. It is thus important to emphasize the need for early testing for possible cardiotoxicity of emerging oncotherapeutics. In this study, we assessed a novel stem cell-derived cardiac model for testing for cardiotoxicity of novel oncotherapeutics. We evaluated the cardiotoxic effect of synthesized derivatives of oncotherapeutics, quercetin (QMJ-2, -5, and -6) and cinnamic acid (NMJ-1, -2, and -3) using human Wharton's jelly mesenchymal stem cells-derived cardiomyocytes (WJCM) against known cardiotoxic oncologic drugs, doxorubicin, 5-fluorouracil, cisplatin. QMJ-6, NMJ-2, and NMJ-3 were not cardiotoxic and had minimum cardiac side effects. They did not show any effect on cardiomyocyte viability, caused low LDH release, and intracellular ROS production kept the calcium flux minimal and protected the active mitochondrial status in cardiomyocytes. They persevered cardiac-specific gene expression as well. However, compounds QMJ-2, QMJ-5, and NMJ-1 were cardiotoxic and the concentration needs to be reduced to prevent toxic effects on cardiomyocytes. Significantly, we were able to demonstrate that WJCM is an efficient cardiac testing model to analyze the cardiotoxicity of drugs in a human context.

Inhibition of breast cancer stem-like cells by a triterpenoid, ursolic acid, via activation of Wnt antagonist, sFRP4 and suppression of miRNA-499a-5p.

Breast cancer, one of the leading causes of death in the world, has been largely considered to be drug resistant because of a small population of drug refractory cells, the cancer stem cells (CSCs). The CSCs are tightly regulated by self-renewal pathways such as the Wnt pathway, which is further regulated by a gamut of microRNAs. In this study, we investigated the effect of ursolic acid (UA), a natural triterpene, on breast CSCs enriched from breast cancer cell lines, MCF7, MDA-MB-231 and T47D and analysed the interplay of the Wnt inhibitor, sFRP4 and an miRNA, miR-499a-5p, in mediating the effect of UA. By using caspase 3/7, ROS, migration, TCF/LEF and CAM assays, overexpressing and inhibiting miR-499a-5p and NanoString PanCancer analysis, we observed that UA had significant anti-CSC ability. There was a link between UA and Wnt/ß-catenin pathway wherein, Wnt was suppressed by upregulation of the antagonist, sFRP4. Furthermore, expression of the oncogenic miR-499a-5p was substantially diminished in CSCs after UA treatment. Notably, the axis by which miR-499a-5p acts is via the TCF/LEF machinery of the Wnt/ß-catenin pathway. Our findings indicate for the first time that UA can target breast CSCs via Wnt by suppressing miR-499a-5p and upregulating the Wnt antagonist, sFRP4.

Encapsulated human mesenchymal stem cells (eMSCs) as a novel anti-cancer agent targeting breast cancer stem cells: Development of 3D primed therapeutic MSCs.

Breast cancer is a leading cause of mortality in women across the globe. The major reason for its recurrence and high mortality is due to the presence of a drug refractory and self-renewing population of cells, the cancer stem cells (CSCs). Mesenchymal stem cells (MSCs) have recently emerged as a promising cell-based therapeutic agent for the treatment of different cancer types. However, the anti-tumor effect of MSCs has been indicated to be substantially reduced by their in vivo tumor-trophic migration property and direct cell-to-cell integration with tumor stromal elements. To address this drawback, the present study uses a biomaterial, sodium alginate, for the encapsulation of MSCs from the perinatal tissue, Wharton's jelly (WJMSCs) into microbeads, to study the effect of WJMSCs beads on breast CSCs derived from two breast cancer cell lines, MDA-MB-231 and MCF7. Encapsulation with sodium alginate facilitated the prevention of direct cell-to-cell interaction and these microbeads provided a three-dimensional (3D) microenvironment for the encapsulated WJMSCs (eWJMSCs). Compared to two dimensional (2D) culture, eWJMSC increased proliferation of WJMSCs with an increase in pluripotency genes, epithelial to mesenchymal transition (EMT), immune-modulation, and angiogenesis. Interestingly, the tumor invasion suppressor protein E-cadherin was highly expressed in eWJMSCs as shown by Western blot analysis. In addition, eWJMSCs had an increased secretion of anti-inflammatory cytokines VEGF, TGF-ß, TNF-α, IFN-γ, IL-10 and -6, and IL-3ß when compared to 2D culture. Treatment of CSCs with eWJMSCs reduced cell viability, inhibited migration, and exerted an anti-angiogenic effect. eWJMSCs treatment of CSCs increased caspase 3/7 activity, nitric oxide production, and reactive oxygen species production, suggesting its anti-tumorigenic activity. Gene expression analysis revealed that CSCs treated with eWJMSCs had a downregulation of pro-proliferation markers, drug transporters, epithelial-mesenchymal transition-associated markers, and angiogenesis related genes. The mode of anti-proliferative action of WJMSCs beads was possibly through inhibition of the Wnt/ß-catenin signaling pathway as indicated by the upregulation of the Wnt antagonists sFRP4 and DKK1. These data suggest that alginate-encapsulated WJMSCs could be an efficient cell contact-free system for developing stem cell-based therapies for CSCs.

Amelioration of methylmercury induced neural damage by essential oil of Selinum vaginatum (Edgew) C. B. Clarke.

Methylmercury (MeHg), an organometallic contaminant is a well spotted cause for a series of disorders, especially in the central nervous system. As there is no proper treatment, Selinum vaginatum (Edgew) C. B. Clarke, a traditional medicinal plant, is taken in the present study for assessing its neuroprotective effect against MeHg induced toxicity using rat brain mitochondrial fractions. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide dye (MTT) assay indicated that there was a reduction in the mitochondrial viability in MeHg treated sample and IC50 value recorded was 2.5µg/ml. Biochemical analysis showed that there was a significant inhibition of glutathione levels (GSH) and catalase activity and an elevation of thiobarbituric acid reactive substances (TBARS) levels in MeHg treated sample. These changes were prevented by co-incubation with essential oil extracted from Selinum vaginatum. The GSH reduction caused by MeHg is restored by essential oil, endorsing its chelating effect, an important molecular mechanism of defense against oxidative injury. Some of the major compounds are detected in Gas chromatography-mass spectrometry (GC-MS) analysis of essential oil, which could be accountable for its neuroprotection against MeHg.

Nanoparticles generated from a tryptophan derivative: physical characterization and anti-cancer drug delivery.

Surging reports of peptide-based nanosystems and their growing potency in terms of biological utility demand for the search of newer and simpler peptide-based systems that could serve as smart templates for the development of self-assembled nanostructures. Use of simple amino acids as monomeric building blocks for synthesizing ensembles of nanostructures have gained momentum in this direction with some reports focusing on the development of nanosystems from single or modified single amino acids. In this work, we have demonstrated self-assembly and nanoparticle formation ability of a single amino acid derivative, N-alpha-(9-fluorenylmethyloxycarbonyl)-N(in)-tert-butyloxycarbonyl-L-tryptophan [Fmoc-Trp(Boc)-OH]. The nanoparticles formed by the amino acid were found to be stable to various environmental perturbations like temperature, salts and showed responsiveness to pH change. These were capable of loading and releasing different bioactive molecules and were biocompatible. These systems demonstrated high cellular uptake and doxorubicin-loaded nanoparticles were found to be more efficient in killing glioma cells as compared to the drug alone. Thus, their simple amino acid-based origin along with the ability to ferry bioactive molecules to various cells, endows them the suitability for future applications in the field of drug delivery.