Synthesis, characterization, and evaluation of pH-sensitive doxorubicin-loaded functionalized graphene oxide in osteosarcoma cells.

Introduction: Doxorubicin (DOX) is one of the most common drugs in cancer treatment. However, its partial solubility along with the high incidence of side effects remains a challenge to tackle. To address these issues, we designed a formulation based on graphene oxide (GO) and used it as an anticancer drug delivery system. Methods: The physical and chemical properties of the formulation were studied using FTIR, SEM, EDX, Mapping, and XRD. Release studies in the in vitro condition were used to evaluate the pH sensitivity of drug release from nanocarriers. Other in vitro studies, including uptake assay, MTT, and apoptosis assay were carried out on the osteosarcoma cell line. Results: in vitro release studies confirmed that the synthesized formulation provides a better payload release profile in acidic conditions, which is usually the case in the tumor site. On the OS cell line, the cytotoxicity of the DOX-loaded nanocarrier (IC50=0.293 µg/mL) and early apoptosis rate (33.80 % ) were higher in comparison to free DOX (IC50=0.472 µg/mL, and early apoptosis rate= 8.31 % ) after 48 hours. Conclusion: In summary, our results suggest a DOX-loaded graphene oxide carrier as a potential platform for targeting cancer cells.

Vitamin D in respiratory viral infections: a key immune modulator?

Respiratory viral infections are common respiratory diseases. Influenza viruses, RSV and SARS-COV2 have the potential to cause severe respiratory infections. Numerous studies have shown that unregulated immune response to these viruses can cause excessive inflammation and tissue damage. Therefore, regulating the antiviral immune response in the respiratory tract is of importance. In this regard, recent years studies have emphasized the importance of vitamin D in respiratory viral infections. Although, the most well-known role of vitamin D is to regulate the metabolism of phosphorus and calcium, it has been shown that this vitamin has other important functions. One of these functions is immune regulation. Vitamin D can regulate the antiviral immune response in the respiratory tract in order to provide an effective defense against respiratory viral infections and prevention from excessive inflammatory response and tissue damage. In addition, this vitamin has preventive effects against respiratory viral infections. Some studies during the COVID-19 pandemic have shown that vitamin D deficiency may be associated with a higher risk of mortality and sever disease in patients with COVID-19. Since, more attention has recently been focused on vitamin D. In this article, after a brief overview of the antiviral immune response in the respiratory system, we will review the role of vitamin D in regulating the antiviral immune response comprehensively. Then we will discuss the importance of this vitamin in influenza, RSV, and COVID-19.

Role of exosomal miRNA in chemotherapy resistance of Colorectal cancer: A systematic review.

The third most common malignancy has been identified as Colorectal cancer (CRC) that conducive to death in most cases. Chemoresistance is a common obstacle to CRC treatment. Circulating exosomal microRNAs (miRNAs) have been shown to reverse chemo-resistance and are promising biomarkers for CRC. The capacity of engineered exosomes to cross biological barriers and deliver functional miRNAs could be used to achieve these proposes. The object of this review is the investigation of the role of exosomal miRNA in the chemo-resistance, diagnosis, and prognosis of CRC. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, electronic databases, PubMed, EMBASE, Web of Science, Scopus were searched from January 1990 to November 2020. Ultimately, eight articles included five in vitro (16 cell lines) and three in vivo examinations. Three studies demonstrated that increasing or decreasing mRNA expression was associated with increasing and decreasing cell proliferation in vitro. The presence of miRNA in two studies increased the sensitivity of the drug and exhibited a considerable growth inhibitory effect on cancer cell proliferation. The apoptotic rate was significantly increased in four studies by increased mRNA expression and reduced mrna expression. Tumor volume of xenograft models in three studies suppressed by antitumor miRNA activity. In contrast, anti-miRNA activity in one study decreased the tumor volume. Exosomal miRNAs can be regulators of chemo-resistance and predict adverse outcomes in CRC patients. In sum, exosomes containing miRNAs can be a promising biomarker for the prognosis and diagnosis of CRC. Subsequent research should be a focus on delineating the function of exosomal miRNA before clinical use.

Long noncoding RNA SNHG7-miRNA-mRNA axes crosstalk with oncogenic signaling pathways in human cancers.

LncRNAs and miRNAs are the two most important non-coding RNAs, which have been identified to be associated with cancer progression or prevention. The dysregulation of lncRNAs conducts tumorigenesis and metastasis in different ways. One of the mechanisms is that lncRNAs interact with miRNAs to regulate distinct cellular and genomic processes and cancer progression. LncRNA SNHG7 as an oncogene sponges miRNAs and develops lncRNA-miRNA-mRNA axes, leading to the regulation of several signaling pathways such as Wnt/ß-Catenin, PI3K/AKT/mTOR, SIRT1, and Snail-EMT. Therefore, in this article, after a brief overview of lncRNA SNHG7-miRNA-mRNA axes' contribution to cancer development, we will discuss the role of lncRNA SNHG7 in the genes expression and signaling pathways related to cancers development via acting as a ceRNA.

Quercetin and Methotrexate in Combination have Anticancer Activity in Osteosarcoma Cells and Repress Oncogenic MicroRNA-223.

INTRODUCTION: Osteosarcoma (OS) is one of the most common bone neoplasms in adolescents. Notable short- and long-term toxic effects of OS chemotherapy regimens have been reported. Hence, new chemotherapeutic agents with the ability to potentiate OS chemotherapy drugs and protect non-tumorous tissues are required. METHODS: Saos-2 cells were treated with Methotrexate (MTX) and Quercetin (Que) (a polyphenolic flavonoid with anti-tumor effects) alone and in combination. MTT assay was performed to investigate the cytotoxicity of the drugs. Moreover, apoptosis-involved genes, including miR-223, p53, BCL-2, CBX7, and CYLD expression were analyzed via qRT-PCR. Annexin V-FITC/PI kit was employed to assess the apoptosis rate. RESULTS: The MTT results showed that Que increases MTX cytotoxicity on OS cells. The measured IC50s are 142.3 µM for QUE and 13.7 ng/ml for MTX. A decline in MTX IC50 value was observed from 13.7 ng/ml to 8.45 ng/ml in the presence of Que. Moreover, the mRNA expression outcomes indicated that the combination therapy significantly up-regulates the tumor suppressor genes, such as p53, CBX7, and CYLD, and declines anti-apoptotic genes BCL-2 and miR-223, which can lead to proliferation inhibition and apoptosis inducement. Furthermore, the apoptosis rate increased significantly from 6.03% in the control group to 38.35% in Saos-2 cells that were treated with the combination of MTX and Que. CONCLUSION: Que, with the potential to boost the anticancer activity of MTX on Saos-2 cancer cells through proliferation inhibition and apoptosis induction, is a good candidate for combination therapy.

The Effect of TQ and Cis in OS.

INTRODUCTION: Osteosarcoma (OS) is a primary bone sarcoma with a high recurrence rate and poorer prognosis. The application of natural agents in combinational therapies can increase the efficacy of treatment and decrease the side effects. Herein, we aimed to evaluate the effects of Thymoquinone (TQ) combined with Cisplatin on apoptosis and its underlying mechanisms in the Saos-2 cells. METHODS: The effects of TQ and Cisplatin on Saos-2 cell viability were measured using an MTT assay. Western blotting was applied for the measurement of γH2AX protein expression. The expression levels of 8-Hydroxy-2'-deoxyguanosine (8-oxo-dG) were evaluated by enzyme-linked immunosorbent assay (ELISA). DCFH-DA fluorescence dye was used to detect reactive oxygen species (ROS) formation. For evaluation of apoptosis, flow cytometry was employed. RESULTS: TQ dramatically promotes the cytotoxic effects of Cisplatin. TQ considerably enhanced the expression levels of 8-oxo-dG and γ-H2AX in Saos-2 cells. After TQ treatment, ROS levels were increased; furthermore, TQ treatment resulted in the potentiation of Cisplatin-induced apoptosis in Saos-2 cells compared to either TQ or Cisplatin treated cells. CONCLUSION: In general, TQ plus Cisplatin resulted in potentiated cellular cytotoxicity by increasing ROS level and inducing oxidative DNA damage, leading to the potent induction of apoptosis in tumor cells.

Molecular mechanisms involved in DNA repair in human cancers: An overview of PI3k/Akt signaling and PIKKs crosstalk.

The cellular genome is frequently subjected to abundant endogenous and exogenous factors that induce DNA damage. Most of the Phosphatidylinositol 3-kinase-related kinases (PIKKs) family members are activated in response to DNA damage and are the most important DNA damage response (DDR) proteins. The DDR system protects the cells against the wrecking effects of these genotoxicants and repairs the DNA damage caused by them. If the DNA damage is severe, such as when DNA is the goal of chemo-radiotherapy, the DDR drives cells toward cell cycle arrest and apoptosis. Some intracellular pathways, such as PI3K/Akt, which is overactivated in most cancers, could stimulate the DDR process and failure of chemo-radiotherapy with the increasing repair of damaged DNA. This signaling pathway induces DNA repair through the regulation of proteins that are involved in DDR like BRCA1, HMGB1, and P53. In this review, we will focus on the crosstalk of the PI3K/Akt and PIKKs involved in DDR and then discuss current achievements in the sensitization of cancer cells to chemo-radiotherapy by PI3K/Akt inhibitors.

Cytotoxicity and apoptosis of nanoparticles on osteosarcoma cells using doxorubicin and methotrexate: A systematic review.

The safe development of nanotechnology and usage of nanoparticles (NPs) require the cellular toxicity examination of these NPs. Systematic studies are necessary to collect related data and comparison of the physicochemical features of NPs and their effects on cellular viability on model systems. In the present study, we systematically reviewed original studies, which investigated the cytotoxic effects and apoptosis of free NPs (loaded with doxorubicin (Dox)/or methotrexate (MTX)) via in vitro models. Articles were systematically collected by screening the literature published online in the following databases; PUBMED and SCOPUS and Web of Science and EMBASE. 23 in vitro cytotoxicity studies with 8 apoptosis examinations were found on osteosarcoma (OS) cell lines (mostly on MG-63). 43.47% of the synthesized NPs (10 studies) showed no cytotoxicity to OS cells. 39.13% of the synthesized NPs (9 studies) showed time and/or concentration related-cytotoxicity. Potent cytotoxic synthesized NP did not state. Significance difference between the half-maximal inhibitory concentration (IC50) of drug and drug/NP reported in all studies. Involved NPs in this systematic review for delivery of Dox/or MTX to OS cells have higher safety index and biocompatibility, although small and positively charged NPs acted more toxic in comparison to larger and negative ones, apoptosis rate like cytotoxicity index was notable in drug/NP group, to apply them in clinical works. Future studies are required to address the mechanisms involved in cytotoxicity and apoptosis with a special focus on in vivo investigations.

Multiple interactions between melatonin and non-coding RNAs in cancer biology.

The melatonin hormone secreted by the pineal gland is involved in physiological functions such as growth and maturation, circadian cycles, and biological activities including antioxidants, anti-tumor, and anti-ischemia. Melatonin not only interacts with proteins but also has functional effects on regulatory RNAs such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs). In this study, we overview various physiological and pathological conditions affecting melatonin through lncRNA and miRNA. The information compiled herein will serve as a solid foundation to formulate ideas for future mechanistic studies on melatonin. It will also provide a chance to more clarify the emerging functions of the non-coding transcriptome.

The importance of co-delivery of nanoparticle-siRNA and anticancer agents in cancer therapy.

According to global statistics, cancer is the second leading cause of death worldwide. Because of the heterogeneity of cancer, single-drug therapy has many limitations due to low efficacy. Therefore, combination therapy with two or more therapeutic agents is being arisen. One of the most important approaches in cancer therapy is the shot down of key genes involved in apoptotic processes and cell cycle. In this regard, siRNA is a good candidate, a highly attractive method to suppressing tumor growth and invasion. Combination therapy with siRNAs and chemotherapeutic agents can overcome the multidrug resistance and increase apoptosis. The efficient delivery of siRNA to the target cell/tissue/organ has been a challenge. To overcome these challenges, the presence of suitable delivery systems by using nanoparticles is interesting. In this review, we discuss the current challenges for successful RNA interference. Also, we suggested proper a strategy for delivering siRNA that can be useful in targeting therapy. Finally, the combination of a variety of anticancer drugs and siRNA through acceptable delivery systems and their effects on cell cycle and apoptosis will be evaluated.

Stabilization of telomere by the antioxidant property of polyphenols: Anti-aging potential.

Aging is a form of a gradual loss of physiological integrity that results in impaired cellular function and ultimately increased vulnerability to disease and death. This process is a significant risk factor for critical age-related disorders such as cancer, diabetes, cardiovascular disease, and neurological conditions. Several mechanisms contribute to aging, most notably progressive telomeres shortening, which can be counteracted by telomerase enzyme activity and increasing in this enzyme activity associated with partly delaying the onset of aging. Individual behaviors and environmental factors such as nutrition affect the life-span by impact the telomerase activity rate. Healthy eating habits, including antioxidant intakes, such as polyphenols, can have a positive effect on telomere length by this mechanism. In this review, after studying the underlying mechanisms of aging and understanding the relationships between telomeres, telomerase, and aging, it has been attempted to explain the effect of polyphenols on reversing the oxidative stress and aging process.

Graphene Oxide: A Promising Material for Regenerative Medicine and Tissue Engineering.

Regenerative medicine and tissue engineering have been considered pioneer fields in the life sciences, with an ultimate goal of restoring or switching lost or impaired body parts. Graphene oxide (GO) is the product of graphene oxidation and presents a great opportunity to make substantial progress in the field of regenerative medicine; for example, it supports the possibility of creating a cellular niche for stem cells on a nanoparticle surface. GO creates a fascinating structure for regulating stem cell behavior, as it can potentially applied to the noninvasive chase of stem cells in vivo, the liberation of active biological factors from stem cell-containing delivery systems, and the intracellular delivery of factors such as growth factors, DNA, or synthetic proteins in order to modulate stem cell differentiation and proliferation. Due to the interesting physicochemical properties of GO and its possible usage in tissue engineering approaches, the present review aims to elaborate on the ways in which GO can improve current regenerative strategies. In this respect, the applicability of GO to the repair and regeneration of various tissues and organs, including cardiac muscle, skeletal muscle, and nervous, bone, cartilage, adipose, and skin tissues, is discussed.