Small activating RNA upregulates NIS expression: promising potential for hepatocellular carcinoma endoradiotherapy

Evaluation of Single Dose and Fractionated Dose of I-131 Radiolabeled Nanoparticles for Triple-Negative Breast Cancer Treatment

Combination chemotherapy is still the standard clinical care for triple-negative breast cancer (TNBC). However, sodium iodide symporter (NIS) uptake by TNBC has opened the potential of NIS as a molecular target for radioiodine theranostic treatments. Radiolabeled poly(lactic-co-glycolic) acid nanocarrier (NINP) was developed for NIS targeted delivery of I-131 to MDA-MB-231 cells to overcome I-131 low uptake in cancer cells and rapid clearance. The NINP diameter of 237 nm has good particle size uniformity and excellent particle stability. Radiochemical purity, radioactive stability, and radiolabeling yield of NINPs over 72 h were >95%. Cytotoxicity confirmed fractionated NINPs over 72 h to be more effective in cell death than single-dose NINP and both single and fractionated Na131I. Cellular uptake in a three-dimensional spheroid confirmed that NINP fractionated-dose achieved ~4.8-fold-higher mean fluorescent intensity than Na131I and ~2.7-fold greater reduction in cell viability compared to single-dose. The NINP fractionated-dose initiated greater cellular DNA damage to cells than single-dose NINP, resulting in inhibition of cell cycle progression, resulting in cell cycle progression being inhibited by cyclin-dependent kinases, which play a vital role in the control of MDA-MB-231 cell cycle. NINPs are biocompatible with blood, and were found to have no negative impact on red blood cells.

Anti-EpCAM Functionalized I-131 Radiolabeled Biomimetic Nanocarrier Sodium/Iodide-Symporter-Mediated Breast-Cancer Treatment

Currently, breast-cancer treatment has a number of adverse side effects and is associated with poor rates of progression-free survival. Therefore, a radiolabeled anti-EpCAM targeted biomimetic coated nanocarrier (EINP) was developed in this study to overcome some of the treatment challenges. The double emulsion method synthesized the poly(lactic-co-glycolic acid) (PLGA) nanoparticle with Na131I entrapped in the core. The PLGA nanoparticle was coated in human red blood cell membranes and labeled with epithelial cell adhesion molecule (EpCAM) antibody to enable it to target EpCAM overexpression by breast-cancer cells. Characterization determined the EINP size as 295 nm, zeta potential as −35.9 mV, and polydispersity as 0.297. EINP radiochemical purity was >95%. Results determined the EINP efficacy against EpCAM positive MCF-7 breast cancer at 24, 48, and 72 h were 69.11%, 77.84%, and 74.6%, respectively, demonstrating that the EINPs achieved greater cytotoxic efficacy supported by NIS-mediated Na131I uptake than the non-targeted 131INPs and Na131I. In comparison, fibroblast (EpCAM negative) treated with EINPs had significantly lower cytotoxicity than Na131I and 131INPs (p < 0.05). Flow cytometry fluorescence imaging visually signified delivery by EINPs specifically to breast-cancer cells as a result of anti-EpCAM targeting. Additionally, the EINP had a favorable safety profile, as determined by hemolysis.

Small Activating RNAs: Towards the Development of New Therapeutic Agents and Clinical Treatments

Small double-strand RNA (dsRNA) molecules can activate endogenous genes via an RNA-based promoter targeting mechanism. RNA activation (RNAa) is an evolutionarily conserved mechanism present in diverse eukaryotic organisms ranging from nematodes to humans. Small activating RNAs (saRNAs) involved in RNAa have been successfully used to activate gene expression in cultured cells, and thereby this emergent technique might allow us to develop various biotechnological applications, without the need to synthesize hazardous construct systems harboring exogenous DNA sequences. Accordingly, this thematic issue aims to provide insights into how RNAa cellular machinery can be harnessed to activate gene expression leading to a more effective clinical treatment of various diseases.

Network analysis reveals essential proteins that regulate sodium-iodide symporter expression in anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is the most rare and lethal form of thyroid cancer and requires effective treatment. Efforts have been made to restore sodium-iodide symporter (NIS) expression in ATC cells where it has been downregulated, yet without complete success. Systems biology approaches have been used to simplify complex biological networks. Here, we attempt to find more suitable targets in order to restore NIS expression in ATC cells. We have built a simplified protein interaction network including transcription factors and proteins involved in MAPK, TGFβ/SMAD, PI3K/AKT, and TSHR signaling pathways which regulate NIS expression, alongside proteins interacting with them. The network was analyzed, and proteins were ranked based on several centrality indices. Our results suggest that the protein interaction network of NIS expression regulation is modular, and distance-based and information-flow-based centrality indices may be better predictors of important proteins in such networks. We propose that the high-ranked proteins found in our analysis are expected to be more promising targets in attempts to restore NIS expression in ATC cells.

Reevaluation of the Effect of Iodine on Thyroid Cell Survival and Function Using PCCL3 and Nthy-ori 3-1 Cells

The appropriate amount of iodine is critical for normal function of thyroid cells synthesizing thyroid hormones. Although normal thyroid cell lines such as rat PCCL3 and FRTL5 and human Nthy-ori 3-1 have been widely used for in vitro studies on physiological and pathophysiological effects of iodine on thyroid cells, we have recently pointed out the critical differences between FRTL5/PCCL3 cells and Nthy-ori 3-1 cells. Therefore, we here directly compared some of the cellular characteristics—iodine uptake, differentiated status, iodine-induced cytotoxicity, and iodine-regulation of autophagy—between PCCL3 and Nthy-ori 3-1 cells. PCCL3 cells express messenger RNAs for thyrotropin receptor and sodium/iodine symporter and incorporate iodine in a thyrotropin-dependent manner, whereas Nthy-ori 3-1 cells do not either. Nevertheless, both cells were comparably resistant to iodine cytotoxicity: Only far excess iodine (5 × 10^–2 M) killed 20% to 40% cells in 24 hours with perchlorate exhibiting no effect, suggesting this cytotoxic effect is due to extracellular iodine. In contrast, a wide range of iodine (5 × 10^–9 to 5 × 10^–2 M) induced autophagy in PCCL3 cells, which was abolished by perchlorate, indicating intracellular iodine-induction of autophagy, but this effect was not observed in Nthy-ori 3-1 cells. In conclusion, it is critical to discriminate the effect of iodine incorporated into cells from that of extracellular iodine on thyroid cells. Iodine-uptake competent thyroid cells such as PCCL3 and FRTL5 cells, not Nthy-ori 3-1 cells, should be used for studies on iodine effect on thyroid cells.

Therapeutic Potential of Small Activating RNAs (saRNAs) in Human Cancers

Background:

RNA is increasingly recognized as a powerful molecule that can be used to control gene expression. Sophisticated, well-engineered RNA-based regulators are being developed as oligotherapeutics.

Methods:

In particular, small activating RNAs (saRNAs) are promising therapeutic options for targeting human diseases. Numerous saRNAs targeting multiple cancers have been developed in preclinical models. One saRNA targeting C/EBPα is currently undergoing clinical trials in liver cancer.

Results and

Conclusion:

In this review, we describe the current working model of the intracellular mechanism of saRNA, discuss the recent progress of saRNA therapeutics in preclinical and clinical trials, and current advances in targeted delivery using aptamers in detail.

Activating the Chromatin by Noncoding RNAs

SIGNIFICANCE

The extent and breadth of transcription have recently been uncovered and this has revealed an extensive array of noncoding RNAs (ncRNAs). The biological role and significance of these ncRNAs have been realized and to date it appears that ncRNAs may have many important regulatory functions. ncRNAs are multifaceted and they induce a complexity of different types of transcriptional and posttranscriptional regulation, including gene activation. Recent Advances: Association of ncRNAs with gene activation is an important finding. Not only enhancer RNA (eRNA) but other types of ncRNAs, including small RNA (sRNA), long-noncoding RNA (lncRNA), microRNA (miRNA), and PIWI-associated RNA (piRNA), have also been implicated in gene activation. Interestingly, they often coincide with histone modifications that favor an open chromatin. In addition, these ncRNAs can recruit key factors important for transcription, including RNA polymerase II. They may directly bind the genomic DNA or act as scaffolds; alternatively, they may loop the chromatin to enhance transcription.

CRITICAL ISSUES

Although the role of small activating (sa)RNAs has been considerably studied, the roles of miRNAs and piRNAs in gene activation still need to be substantiated and issues of specificity require further studies.

FUTURE DIRECTIONS

The ncRNA field is coming out of its infancy and we are gaining a global picture of the importance of ncRNAs. However, detailed mechanisms of action of the different ncRNAs are still to be determined. This may reveal novel ways of transcriptional regulation, which will facilitate our ability to utilize these regulatory pathways for research and therapeutic purposes. Antioxid. Redox Signal. 29, 813-831.