Recent advances in nanoscience and nanotechnology radically changed the way we diagnose, treat, and prevent various diseases in all aspects of human life. Silver nanoparticles (AgNPs) are one of the most vital and fascinating nanomaterials among several metallic nanoparticles that are involved in biomedical applications. AgNPs play an important role in nanoscience and nanotechnology, particularly in nanomedicine. Although several noble metals have been used for various purposes, AgNPs have been focused on potential applications in cancer diagnosis and therapy. In this review, we discuss the synthesis of AgNPs using physical, chemical, and biological methods. We also discuss the properties of AgNPs and methods for their characterization. More importantly, we extensively discuss the multifunctional bio-applications of AgNPs; for example, as antibacterial, antifungal, antiviral, anti-inflammatory, anti-angiogenic, and anti-cancer agents, and the mechanism of the anti-cancer activity of AgNPs. In addition, we discuss therapeutic approaches and challenges for cancer therapy using AgNPs. Finally, we conclude by discussing the future perspective of AgNPs.

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Silver Nanoparticles: Synthesis, Characterization, Properties, Applications, and Therapeutic Approaches

https://aasldpubs.onlinelibrary.wiley.com/doi/epdf/10.1002/hep.29270

Circular RNA circMTO1 acts as the sponge of microRNA-9 to suppress hepatocellular carcinoma progression.

Silver nanoparticles: synthesis, properties, and therapeutic applications.

Silver Nanoparticles: Therapeutical Uses, Toxicity, and Safety Issues

Nanoparticles are emerging as a useful tool for a wide variety of biomedical, consumer and instrumental applications that include drug delivery systems, biosensors and environmental sensors. In particular, nanoparticles have been shown to offer greater specificity with enhanced bioavailability and less detrimental side effects as compared to the existing conventional therapies in nanomedicine. Hence, bionanotechnology has been receiving immense attention in recent years. However, despite the extensive use of nanoparticles today, there is still a limited understanding of nanoparticle-mediated toxicity. Both in vivo and in vitro studies have shown that nanoparticles are closely associated with toxicity by increasing intracellular reactive oxygen species (ROS) levels and/or the levels of pro-inflammatory mediators. The homeostatic redox state of the host becomes disrupted upon ROS induction by nanoparticles. Nanoparticles are also known to up-regulate the transcription of various pro-inflammatory genes, including tumor necrosis factor-α and IL (interleukins)-1, IL-6 and IL-8, by activating nuclear factor-kappa B (NF-κB) signaling. These sequential molecular and cellular events are known to cause oxidative stress, followed by severe cellular genotoxicity and then programmed cell death. However, the exact molecular mechanisms underlying nanotoxicity are not fully understood. This lack of knowledge is a significant impediment in the use of nanoparticles in vivo. In this review, we will provide an assessment of signaling pathways that are involved in the nanoparticle- induced oxidative stress and propose possible strategies to circumvent nanotoxicity.

https://www.mdpi.com/2079-4991/5/3/1163/pdf

Nanotoxicity: An Interplay of Oxidative Stress, Inflammation and Cell Death.

Anti-leukemia activity of PVP-coated silver nanoparticles via generation of reactive oxygen species and release of silver ions

Although the generation of BCR-ABL is the molecular hallmark of chronic myeloid leukemia (CML), the comprehensive molecular mechanisms of the disease remain unclear yet. Growth arrest specific 2 (GAS2) regulates multiple cellular functions including cell cycle, apoptosis and calpain activities. In the present study, we found GAS2 was up-regulated in CML cells including CD34+ progenitor cells compared to their normal counterparts. We utilized RNAi and the expression of dominant negative form of GAS2 (GAS2DN) to target GAS2, which resulted in calpain activity enhancement and growth inhibition of both K562 and MEG-01 cells. Targeting GAS2 also sensitized K562 cells to Imatinib mesylate (IM). GAS2DN suppressed the tumorigenic ability of MEG-01 cells and impaired the tumour growth as well. Moreover, the CD34+ cells from CML patients and healthy donors were transduced with control and GAS2DN lentiviral vectors, and the CD34+ transduced (YFP+) progeny cells (CD34+YFP+) were plated for colony-forming cell (CFC) assay. The results showed that GAS2DN inhibited the CFC production of CML cells by 57±3% (n = 3), while affected those of normal hematopoietic cells by 31±1% (n = 2). Next, we found the inhibition of CML cells by GAS2DN was dependent on calpain activity but not the degradation of beta-catenin. Lastly, we generated microarray data to identify the differentially expressed genes upon GAS2DN and validated that the expression of HNRPDL, PTK7 and UCHL5 was suppressed by GAS2DN. These 3 genes were up-regulated in CML cells compared to normal control cells and the growth of K562 cells was inhibited upon HNRPDL silence. Taken together, we have demonstrated that GAS2 is up-regulated in CML cells and the inhibition of GAS2 impairs the growth of CML cells, which indicates GAS2 is a novel regulator of CML cells and a potential therapeutic target of this disease.

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Growth arrest specific 2 is up-regulated in chronic myeloid leukemia cells and required for their growth.

TWIST2 has a dual function in tumors. Its implication in the initiation and metastasis of various solid tumors is well established, and its tumor-suppressor role in murine osteosarcoma cells has been reported recently. However, the function of TWIST2 and its underlying mechanisms in human normal and malignant hematopoiesis remain unclear. In the present study, we found that TWIST2 directly regulated p21 in human hematopoietic cells and whose silence promoted cell proliferation and cell cycle progression. Hypermethylation of TWIST2 occurred to 23 out of the 75 adult acute myeloid leukemia (AML) patients and resulted in the impaired expression of both TWIST2 and p21. Conversely, TWIST2 overexpression inhibited the growth of AML cells partially through its direct activation of p21 with intact HLH (helix-loop-helix) domain. The microarray data and gene expression validation showed that TWIST2 was sufficient to activate known tumor-suppressor genes, whereas suppress known oncogenes, which further supported its inhibitory effect against AML cells. Taken together, our data have identified a novel TWIST2-p21 axis that modulates the cell cycle of both normal and leukemic cells and demonstrated that the direct regulation of p21 by TWIST2 has a role in its tumor-suppressor function in AML.

Regulation of p21 by TWIST2 contributes to its tumor-suppressor function in human acute myeloid leukemia.

CD14 is involved in primary immune and inflammatory responses. The -159 C/T variation in the CD14 gene plays an important role in regulating CD14 expression and has been associated with the susceptibility to various diseases, including allergies. In this study, we examined the association between the C-159T polymorphism and atopic asthma susceptibility in children from Southeastern China. The study population included 746 unrelated children of Chinese Han nationality (362 patients with atopic asthma and 384 healthy controls). CD14 gene polymorphisms were identified by direct sequencing of polymerase chain reaction products. Total immunoglobulin E (IgE) levels in human serum samples were determined using an enzyme-linked immunosorbent assay. Individuals carrying the TT genotypes for rs2569190 were significantly associated with an increased risk of atopic asthma compared with those carrying the wild-type homozygous CC genotypes [adjusted odds ratio (OR) by gender and age, from 1.075-2.398, P = 0.025]. Total serum IgE levels in TT genotype carriers were significantly higher than those in CC genotype carriers in atopic asthma patients (286.3 ± 161.5 IU/mL vs 248.3 ± 147.8 IU/mL). Our data suggest that the CD14 TT genotype may be a genetic susceptibility marker for atopic asthma in Chinese Han children.

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Association of CD14 C159T polymorphism with atopic asthma susceptibility in children from Southeastern China: a case-control study.

Chronic myeloid leukemia (CML) originates from normal hematopoietic stem cells acquiring Philadelphia chromosome (Ph) to generate BCR-ABL fusion gene whose protein product has deregulated tyrosine kinase activity. Specific inhibitors against BCR-ABL, such as Imatinib mesylate (IM), have greatly improved CML management; however, no single agent is a cure yet. Delivery of microRNA (miRNA) using non-viral vectors has been utilized to inhibit various cancer cells; however, the efficacy of this approach to target CML stem/progenitor cells has not been elucidated. In this study, we firstly validated that spermine-introduced pullulan (Ps) was a robust non-viral vector for delivery of miRNA to CML cells, including the CD34+ cells from clinical isolates. We then found that the miR-181a/RALA (V-ral simian leukemia viral oncogene homolog A) axis was aberrantly expressed in the CML CD34+ cells. The delivery of miR-181a specifically inhibited the growth of CML CD34+ cells, possibly via the inhibition of RALA. In contrast, miR-181a did not evidently affect the normal hematopoietic CD34+ cells. In addition, miR-181a increased IM sensitivity of the CD34+ CML cells. Taken together, we have therefore demonstrated that the delivery of miR-181a using Ps to CML stem/progenitor cells leads to their growth inhibition and enhancement of IM sensitivity, which will possibly be beneficial to CML treatment.

Haixia Zhou

Papers

Anti-leukemia activity of PVP-coated silver nanoparticles via generation of reactive oxygen species and release of silver ions

Growth arrest specific 2 is up-regulated in chronic myeloid leukemia cells and required for their growth.

Regulation of p21 by TWIST2 contributes to its tumor-suppressor function in human acute myeloid leukemia.

Association of CD14 C159T polymorphism with atopic asthma susceptibility in children from Southeastern China: a case-control study.

Modulating the Growth and Imatinib Sensitivity of Chronic Myeloid Leukemia Stem/Progenitor Cells with Pullulan/MicroRNA Nanoparticles In Vitro.