A comprehensive overview on the crosstalk between microRNAs and viral pathogenesis and infection.

Infections caused by viruses as the smallest infectious agents, pose a major threat to global public health. Viral infections utilize different host mechanisms to facilitate their own propagation and pathogenesis. MicroRNAs (miRNAs), as small noncoding RNA molecules, play important regulatory roles in different diseases, including viral infections. They can promote or inhibit viral infection and have a pro-viral or antiviral role. Also, viral infections can modulate the expression of host miRNAs. Furthermore, viruses from different families evade the host immune response by producing their own miRNAs called viral miRNAs (v-miRNAs). Understanding the replication cycle of viruses and their relation with host miRNAs and v-miRNAs can help to find new treatments against viral infections. In this review, we aim to outline the structure, genome, and replication cycle of various viruses including hepatitis B, hepatitis C, influenza A virus, coronavirus, human immunodeficiency virus, human papillomavirus, herpes simplex virus, Epstein-Barr virus, Dengue virus, Zika virus, and Ebola virus. We also discuss the role of different host miRNAs and v-miRNAs and their role in the pathogenesis of these viral infections.

BRD4 expression and its regulatory interaction with miR-26a-3p, DLG5-AS1, and JMJD1C-AS1 lncRNAs in gastric cancer progression.

Gastric cancer remains a significant health challenge despite advancements in diagnosis and treatment. Early detection is critical to reducing mortality, necessitating the investigation of molecular mechanisms underlying gastric cancer progression. This study focuses on BRD4 expression and its correlation with miR-26a-3p, DLG5-AS1, and JMJD1C-AS1 lncRNAs in gastric cancer. Analysis of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets revealed significant upregulation of BRD4 in gastric cancer tissues compared to normal tissues, correlating negatively with miR-26a-3p and positively with DLG5-AS1 and JMJD1C-AS1 lncRNAs. Quantitative RT-PCR confirmed these findings in 25 gastric cancer tissue samples and 25 normal samples. BRD4's overexpression was associated with reduced survival rates and older patient age. MiR-26a-3p, a known tumor suppressor, showed decreased expression in gastric cancer tissues, with ROC analysis suggesting it, alongside BRD4, as a potential diagnostic biomarker. Additionally, bioinformatics predicted miR-26a-3p's interaction with BRD4 mRNA. Upregulated lncRNAs DLG5-AS1 and JMJD1C-AS1 likely act as competing endogenous RNAs, sponging miR-26a-3p, thus promoting BRD4 dysregulation. These lncRNAs have not been previously studied in gastric cancer. The findings propose a novel BRD4/lncRNA/miRNA regulatory axis in gastric cancer, highlighting the potential of BRD4, DLG5-AS1, and JMJD1C-AS1 as biomarkers for early diagnosis. Further studies with larger sample sizes and in vivo and in vitro experiments are needed to elucidate this regulatory mechanism's role in gastric cancer progression.

Recent advances in gene delivery nanoplatforms based on spherical nucleic acids.

Gene therapy is a therapeutic option for mitigating diseases that do not respond well to pharmacological therapy. This type of therapy allows for correcting altered and defective genes by transferring nucleic acids to target cells. Notably, achieving a desirable outcome is possible by successfully delivering genetic materials into the cell. In-vivo gene transfer strategies use two major classes of vectors, namely viral and nonviral. Both of these systems have distinct pros and cons, and the choice of a delivery system depends on therapeutic objectives and other considerations. Safe and efficient gene transfer is the main feature of any delivery system. Spherical nucleic acids (SNAs) are nanotechnology-based gene delivery systems (i.e., non-viral vectors). They are three-dimensional structures consisting of a hollow or solid spherical core nanoparticle that is functionalized with a dense and highly organized layer of oligonucleotides. The unique structural features of SNAs confer them a high potency in internalization into various types of tissue and cells, a high stability against nucleases, and efficay in penetrating through various biological barriers (such as the skin, blood-brain barrier, and blood-tumor barrier). SNAs also show negligible toxicity and trigger minimal immune response reactions. During the last two decades, all these favorable physicochemical and biological attributes have made them attractive vehicles for drug and nucleic acid delivery. This article discusses the unique structural properties, types of SNAs, and also optimization mechanisms of SNAs. We also focus on recent advances in the synthesis of gene delivery nanoplatforms based on the SNAs.

Interaction of noncoding RNAs with hippo signaling pathway in cancer cells and cancer stem cells.

The Hippo signaling pathway has a regulatory function in the organogenesis process and cellular homeostasis, switching the cascade reactions of crucial kinases acts to turn off/on the Hippo pathway, altering the downstream gene expression and thereby regulating proliferation, apoptosis, or stemness. Disruption of this pathway can lead to the occurrence of various disorders and different types of cancer. Recent findings highlight the importance of ncRNAs, such as microRNA, circular RNA, and lncRNAs, in modulating the Hippo pathway. Defects in ncRNAs can disrupt Hippo pathway balance, increasing tumor cells, tumorigenesis, and chemotherapeutic resistance. This review summarizes ncRNAs' inhibitory or stimulatory role in - Hippo pathway regulation in cancer and stem cells. Identifying the relation between ncRNAs and the components of this pathway could pave the way for developing new biomarkers in the treatment and diagnosis of cancers.

MicroRNA-143 overexpression enhances the chemosensitivity of A172 glioblastoma cells to carmustine.

As an aggressive malignancy, glioblastoma multiforme (GBM) is the most common type of brain tumor. The existing treatments have shown limited achievement in increasing the overall survival of patients. Therefore, identifying the key molecules involved in GBM will provide new potential therapeutic targets. Carmustine is an alkylating agent used as a supplementary therapeutic option for GBM. However, the extensive use of carmustine has been limited by uncertainty about its efficacy. MicroRNAs (miRNAs) are essential in post-transcriptional gene regulation. Many aberrantly expressed miRNAs have been detected in various types of human cancer, including GBM. In this study, we evaluated the potential therapeutic effect of miR-143 in combination with carmustine on GBM cells. A172 cells were transfected with miR-143 mimics and then treated with carmustine. To assess the cell viability, apoptosis induction, and cell cycle progression, the MTT assay, Annexin V/PI apoptosis assay, and flow cytometry were used, respectively. Furthermore, qRT-PCR assay was applied to evaluate the expression level of genes related to apoptosis. The obtained results evidenced that miR-143 transfection could promote the sensitivity of A172 cells to carmustine and enhance carmustine-induced apoptosis via modulating the expression levels of Caspase-3, Caspase-9, Bax, and Bcl-2. Also, our results revealed that combination therapy could effectively diminish cell cycle progression in A172 cells. In conclusion, these results confirmed that miR-143 could enhance carmustine-mediated suppression of cell proliferation and improve the chemosensitivity of A172 cells to this chemotherapeutic agent. Therefore, miR-143 combination therapy may be a promising GBM treatment approach.

Investigating the effect of LncRNA DLGAP1-AS2 suppression on chemosensitivity of gastric cancer to chemotherapy.

Gastric cancer, as the fifth most frequent disease and the fourth foremost cause of cancer-related death worldwide, remains a main clinical challenge due to its poor prognosis, limited treatment choices, and ability to metastasize. Combining siRNAs to suppress lncRNA with chemotherapeutic medications is a novel treatment approach that eventually increases the therapeutic efficacy of the drug while lessening its adverse effects. This study was performed with the purpose of examining the impact of inhibiting DLGAP1-AS2 expression on gastric cancer cells' drug chemosensitivity. AGS cells were cultured as the study cell line and were transfected with an optimum dose of DLGAP1-AS2 siRNA and then treated with oxaliplatin. Cell viability was examined using the MTT technique. Apoptosis and cell cycle were evaluated using Annexin V/PI staining and flow cytometry. Later, the scratch test was conducted to investigate the ability of cells to migrate, and the inhibition of the stemness of AGS cells was further investigated through the colony formation method. Finally, the qRT-PCR technique was used to assess the expression of Bax, Bcl-2, Caspase-3, p53, MMP-2, and CD44 genes. The MTT test indicated the effect of gene therapy with siRNA and oxaliplatin in combination reduced the chemotherapy drug dose to 29.92 µM and increased AGS cells' sensitivity to oxaliplatin. Also, the combination therapy caused a significant increase in apoptosis. However, it reduced the stemness feature, the rate of cell viability, proliferation, and metastasis compared to the effect of each treatment alone; the results also showed the arrest of the cell cycle in the Sub G1 phase after the combined treatment and a further reduction in the number and size of the formed colonies. Suppressing the expression of lncRNA DLGAP1-AS2 by siRNA followed by treatment with oxaliplatin can be utilized as an effective and new therapeutic technique for gastric cancer therapy.

Let-7a-3p overexpression increases chemosensitivity to carmustine and synergistically promotes autophagy and suppresses cell survival in U87MG glioblastoma cancer cells.

In terms of primary brain tumors, glioblastoma is one of the most aggressive and common brain tumors. The high resistance of glioblastoma to chemotherapy has made it vital to find alternative treatments and biological mechanisms to reduce the survival of cancer cells. Given that, the objective of the present research was to explore the potential of let-7a-3p when used in combination with carmustine in human glioblastoma cancer cells. Based on previous studies, the expression of let-7a is downregulated in the U87MG cell line. Let-7a-3p transfected into U87MG glioblastoma cells. Cell viability of the cells was assessed by MTT assay. The apoptotic induction in U87MG cancerous cells was determined through the utilization of DAPI and Annexin V/PI staining techniques. Moreover, the induction of autophagy and cell cycle arrest was evaluated by flow cytometry. Furthermore, cell migration was evaluated by the wound healing assay while colony formation assay was conducted to evaluate colony formation. Also, the expression of the relevant genes was evaluated using qRT-PCR. Transfection of let-7a-3p mimic in U87MG cells increased the expression of the miRNA and also increased the sensitivity of U87MG cells to carmustine. Let-7a-3p and carmustine induced sub-G1 and S phase cell cycle arrest, respectively. Combination treatment of let-7a-3p and carmustine synergistically increased arrested cells and induced apoptosis through regulating involved genes including P53, caspase-3, Bcl-2, and Bax. Combined treatment with let-7a-3p and carmustine also induced autophagy and increased the expression of the ATG5 and Beclin 1 (ATG6). Furthermore, let-7a-3p combined with carmustine inhibited cell migration via decreasing the expression of MMP-2. Moreover, the combination therapy decreased the ability of U87MG to form colonies through downregulating CD-44. In conclusion, our work suggests that combining let-7a-3p replacement therapy with carmustine treatment could be considered a promising strategy in treatment and can increase efficiency of glioblastoma chemotherapy.