Silencing of microRNA-517a induces oxidative stress injury in melanoma cells via inactivation of the JNK signaling pathway by upregulating CDKN1C

FOXO3 Inhibits the Cisplatin Resistance and Progression of Melanoma Cells by Promoting CDKN1C Transcription

BACKGROUND

Forkhead box O3 (FOXO3) and cyclin dependent kinase inhibitor 1 C Gene (CDKN1C) have been shown to be involved in the melanoma process, but their roles in the cisplatin (DDP) resistance of melanoma remain unclear.

METHODS

The mRNA levels of CDKN1C and FOXO3 were measured using quantitative real-time PCR. The protein levels of CDKN1C, FOXO3 and mitochondrial oxidative phosphorylation (mtOXPHOS)-related markers were determinant by western blot analysis. The DDP resistance, proliferation, and apoptosis of melanoma cells were assessed by cell counting kit 8 assay, colony formation assay and flow cytometry. Glucose consumption, lactate production and ATP level were detected to assess glycolysis. The regulation of FOXO3 on CDKN1C was confirmed by ChIP assay and dual-luciferase reporter assay. In vivo experiments were performed to evaluate the effect of FOXO3 on DDP sensitivity in melanoma tumor tissues.

RESULTS

CDKN1C and FOXO3 were downregulated in chemoresistant melanoma tissues, and their low expression levels were related to the poor prognosis of melanoma patients. Overexpression of CDKN1C and FOXO3 repressed DDP resistance, proliferation, and glycolysis, while promoted apoptosis and mtOXPHOS in DDP-resistant melanoma cells. Further analysis suggested that FOXO3 could bind to CDKN1C promoter region to enhance its transcription. Besides, CDKN1C knockdown reversed the regulation of FOXO3 on melanoma cell DDP resistance and progression. Moreover, FOXO3 overexpression enhanced the DDP sensitivity of melanoma tumor tissues in vivo.

CONCLUSION

FOXO3 promoted the transcription of CDKN1C, thereby inhibiting the DDP resistance and progression of melanoma cells.

miRNAs Involvement in Modulating Signalling Pathways Involved in Ros-Mediated Oxidative Stress in Melanoma

Reactive oxygen species (ROS) are intermediates in oxidation-reduction reactions with the capacity to modify biomolecules and temporarily or permanently alter cell behaviour through signalling pathways under physiological and pathophysiological conditions where there is an imbalance between oxidative factors and the antioxidant response of the organism, a phenomenon known as oxidative stress. Evidence suggests that the differential modulation of ROS-mediated oxidative stress occurs in the pathogenesis and progression of melanoma, and that this imbalance in redox homeostasis appears to be functionally linked to microRNA (miRNA o miRs)-mediated non-mutational epigenetic reprogramming involving genes and transcription factors. The relationship between ROS-mediated stress control, tumour microenvironment, and miRNA expression in melanoma is not fully understood. The aim of this review is to analyse the involvement of miRNAs in the modulation of the signalling pathways involved in ROS-mediated oxidative stress in melanoma. It is hoped that these considerations will contribute to the understanding of the mechanisms associated with a potential epigenetic network regulation, where the modulation of oxidative stress is consolidated as a common factor in melanoma, and therefore, a potential footprint poorly documented.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

The Roles of MiRNAs (MicroRNAs) in Melanoma Immunotherapy

Melanoma is the most aggressive form of skin cancer, characterized by life-threatening and rapidly spreading progression. Traditional targeted therapy can alleviate tumors by inactivating hyperactive kinases such as BRAF or MEK but inevitably encounters drug resistance. The advent of immunotherapy has revolutionized melanoma treatment and significantly improved the prognosis of melanoma patients. MicroRNAs (miRNAs) are intricately involved in innate and adaptive immunity and are implicated in melanoma immunotherapy. This systematic review describes the roles of miRNAs in regulating the functions of immune cells in skin and melanoma, as well as the involvement of miRNAs in pharmacology including the effect, resistance and immune-related adverse events of checkpoint inhibitors such as PD-1 and CTLA-4 inhibitors, which are used for treating cutaneous, uveal and mucosal melanoma. The expressions and functions of miRNAs in immunotherapy employing tumor-infiltrating lymphocytes and Toll-like receptor 9 agonists are also discussed. The prospect of innovative therapeutic strategies such as the combined administration of miRNAs and immune checkpoint inhibitors and the nanotechnology-based delivery of miRNAs are also provided. A comprehensive understanding of the interplay between miRNAs and immunotherapy is crucial for the discovery of reliable biomarkers and for the development of novel miRNA-based therapeutics against melanoma.

microRNAs associated with the pathogenesis and their role in regulating various signaling pathways during Mycobacterium tuberculosis infection

Despite more than a decade of active study, tuberculosis (TB) remains a serious health concern across the world, and it is still the biggest cause of mortality in the human population. Pathogenic bacteria recognize host-induced responses and adapt to those hostile circumstances. This high level of adaptability necessitates a strong regulation of bacterial metabolic characteristics. Furthermore, the immune reponse of the host virulence factors such as host invasion, colonization, and survival must be properly coordinated by the pathogen. This can only be accomplished by close synchronization of gene expression. Understanding the molecular characteristics of mycobacterial pathogenesis in order to discover therapies that prevent or resolve illness relies on the bacterial capacity to adjust its metabolism and replication in response to various environmental cues as necessary. An extensive literature details the transcriptional alterations of host in response to in vitro environmental stressors, macrophage infection, and human illness. Various studies have recently revealed the finding of several microRNAs (miRNAs) that are believed to play an important role in the regulatory networks responsible for adaptability and virulence in Mycobacterium tuberculosis. We highlighted the growing data on the existence and quantity of several forms of miRNAs in the pathogenesis of M. tuberculosis, considered their possible relevance to disease etiology, and discussed how the miRNA-based signaling pathways regulate bacterial virulence factors.

miR-517b-3p promotes the progression of portal vein tumor thrombus via activating Wnt/β-catenin signaling pathway in hepatocellular carcinoma

AIMS

This study was aimed to investigate the expression patterns and prognostic value of microRNA-517b-3p (miR-517b-3p) in hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT).

METHODS

The expression of miR-517b-3p in PVTT tissues and cells was estimated using qRT-PCR. Through Kaplan-Meier survival analysis, Cox regression assay and ROC analysis, the significance of miR-517b-3p was explored. In addition, cell experiments were performed to examine the functional role of miR-517b-3p during progression of PVTT. Moreover, the biological process and biological pathway analysis analyses were conducted through GSEA and FunRich. Besides, the protein-protein interaction (PPI) network of the DEGs was established through cBioPortal website.

RESULTS

Compared with the controls, the miR-517b-3p was upregulated in both PVTT tissues and cells. The upregulated miR-517b-3p, which served as a potential diagnostic biomarker to distinguish PVTT from PT and controls, was associated with poor overall survival and acted as an independent prognostic factor. The cell proliferation, migration and invasion were proved to be enhanced by overexpression of miR-517b-3p. Furthermore, Wnt/β-catenin signaling was suppressed by miR-517b-3p knockdown and might be involved in the progression of PVTT.

CONCLUSION

miR-517b-3p may promote PVTT cell proliferation, migration and invasion via activation of Wnt/β-catenin signaling pathway. Meanwhile, miR-517b-3p has overexpression in PVTT samples, and serves as a candidate diagnostic and prognostic biomarker in HCC patients with PVTT.

Regulation of miRNAs Expression by Mutant p53 Gain of Function in Cancer

The p53 roles have been largely described; among them, cell proliferation and apoptosis control are some of the best studied and understood. Interestingly, the mutations on the six hotspot sites within the region that encodes the DNA-binding domain of p53 give rise to other very different variants. The particular behavior of these variants led to consider p53 mutants as separate oncogene entities; that is, they do not retain wild type functions but acquire new ones, namely Gain-of-function p53 mutants. Furthermore, recent studies have revealed how p53 mutants regulate gene expression and exert oncogenic effects by unbalancing specific microRNAs (miRNAs) levels that provoke epithelial-mesenchymal transition, chemoresistance, and cell survival, among others. In this review, we discuss recent evidence of the crosstalk between miRNAs and mutants of p53, as well as the consequent cellular processes dysregulated.

Synthesis, anticancer evaluation and molecular docking of new benzothiazole scaffolds targeting FGFR-1

This work deals with the design and synthesis of a series of new substituted 2-arylbenzothiazole compounds attached to 4-oxothiazolidin-2-ylidene ring 2-12 and chain elongation with different amino acids and their corresponding ester derivatives 13-18. All prepared derivatives were screened for their in vitro cytotoxicity activities against two cancer cell lines (HepG-2 and MCF-7) in comparison with doxorubicin; in addition to their safety towards thenormal cell line. Furthermore, all compounds 2-18 were evaluated as FGFR-1 inhibitors using AZD4547 as a reference. The 4-oxothiazolidin-2-ylidene derivatives 3 and 8 exhibited the highest cytotoxic activity (IC_{50 HepG-2} = 2.06, 2.21 µM and IC_{50 MCF-7} = 0.73, 0.77 µM, respectively) through their promising FGFR-1 suppression effects (IC₅₀ = 16.31 and 18.08 nM, respectively) in comparison to AZD4547 (IC₅₀ = 21.45 nM). Cell cycle and apoptosis analysis indicated that compounds 3 and 8 induce pronounced increase in the cell percentages at pre-G₁ and G₂/M phase compared to the untreated MCF-7 cancer cells, in addition to their up regulation of caspase-3/7/9. The molecular docking simulation was created to elucidate the binding modes of benzothiazole derivatives 1-18 bearing various scaffolds within the ATP-binding pocket of FGFR-1 enzyme compared with AZD4547.

MicroRNA Signature in Melanoma: Biomarkers and Therapeutic Targets

Melanoma is the utmost fatal kind of skin neoplasms. Molecular changes occurring during the pathogenic processes of initiation and progression of melanoma are diverse and include activating mutations in BRAF and NRAS genes, hyper-activation of PI3K/AKT pathway, inactivation of p53 and alterations in CDK4/CDKN2A axis. Moreover, several miRNAs have been identified to be implicated in the biology of melanoma through modulation of expression of genes being involved in these pathways. In the current review, we provide a summary of the bulk of information about the role of miRNAs in the pathobiology of melanoma, their possible application as biomarkers and their emerging role as therapeutic targets for this kind of skin cancer.

LncRNA MIR205HG regulates melanomagenesis via the miR-299-3p/VEGFA axis

In this study, we investigated the role of lncRNA MIR205HG in melanomagenesis. Quantitative real-time PCR (qRT-PCR) analysis showed that MIR205HG levels were significantly upregulated in melanoma cell lines compared to normal human melanocytes. Similarly, MIR205HG levels were significantly higher melanoma tissues than adjacent normal skin tissues (n=30). CCK-8 and flow cytometry assays showed that MIR205HG knockdown significantly decreased the viability of melanoma cells. Dual luciferase reporter and RNA pull-down assays confirmed that MIR205HG directly binds to microRNA (miR)-299-3p. Targetscan analysis and dual luciferase reporter assays showed that miR-299-3p directly binds to the 3'UTR of VEGFA mRNA. Wound healing and transwell invasion assays showed that MIR205HG knockdown decreased in vitro migration and invasiveness of melanoma cells, and these effects were reversed by treatment with miR-299-3p inhibitor. MIR205HG-silenced melanoma cells showed increased miR-299-3p expression and lower levels of both VEGFA mRNA and protein. Tumor volumes were significantly smaller in nude mice xenografted with MIR205HG knockdown melanoma cells than the controls. These results demonstrate that MIR205HG supports melanoma growth via the miR-299-3p/VEGFA axis. This makes MIR205HG a potential therapeutic target for the treatment of melanoma.

Computational Drug Repositioning Identifies Statins as Modifiers of Prognostic Genetic Expression Signatures and Metastatic Behavior in Melanoma

Despite advances in melanoma treatment, more than 70% of patients with distant metastasis die within 5 years. Proactive treatment of early melanoma to prevent metastasis could save lives and reduce overall healthcare costs. Currently, there are no treatments specifically designed to prevent early melanoma from progressing to metastasis. We used the Connectivity Map to conduct an in silico drug screen and identified 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) as a drug class that might prevent melanoma metastasis. To confirm the in vitro effect of statins, RNA sequencing was completed on A375 cells after treatment with fluvastatin to describe changes in the melanoma transcriptome. Statins induced differential expression in genes associated with metastasis and are used in commercially available prognostic tests for melanoma metastasis. Finally, we completed a chart review of 475 patients with melanoma. Patients taking statins were less likely to have metastasis at the time of melanoma diagnosis in both univariate and multivariate analyses (24.7% taking statins vs. 37.6% not taking statins, absolute risk reduction = 12.9%, P = 0.038). These findings suggest that statins might be useful as a treatment to prevent melanoma metastasis. Prospective trials are required to verify our findings and to determine the mechanism of metastasis prevention.

miR-541 serves as a prognostic biomarker of osteosarcoma and its regulatory effect on tumor cell proliferation, migration and invasion by targeting TGIF2

Background

Several studies reported the dysregulation of miR-541 in the progression of some human malignancies. Osteosarcoma (OS) is one of the most common primary malignant bone tumors. This study aimed to assess the expression and clinical significance of miR-541 in OS patients and explore the biological function of miR-541 in tumor progression.

Methods

Expression of miR-541 was detected by quantitative real-time PCR, and its prognostic value was evaluated using Kaplan-Meier survival analysis. The biological function of miR-541 was examined by analyzing its effects on OS cell proliferation, migration and invasion. Additionally, the underlying potential target of miR-541 was predicated and analyzed.

Results

The expression of miR-541 was significantly decreased in OS tissues and cell lines. The deregulated expression of miR-541 in tumor tissues was associated with the overall survival of OS patients and was a potential independent prognostic indicator. In OS cells, the overexpression of miR-541 could inhibit cell proliferation, migration and invasion. The luciferase activity results indicated that TGIF2 was a potential target of miR-541.

Conclusion

The results of this study revealed that the decreased miR-541 expression in OS patients may serve as a prognostic biomarker, and that the overexpression of miR-541 in OS cells results in inhibited cell proliferation, migration and invasion, indicating the potential of miR-541 as a therapeutic target in OS treatment.

When Oxidative Stress Meets Epigenetics: Implications in Cancer Development

Cancer is one of the leading causes of death worldwide and it can affect any part of the organism. It arises as a consequence of the genetic and epigenetic changes that lead to the uncontrolled growth of the cells. The epigenetic machinery can regulate gene expression without altering the DNA sequence, and it comprises methylation of the DNA, histones modifications, and non-coding RNAs. Alterations of these gene-expression regulatory elements can be produced by an imbalance of the intracellular environment, such as the one derived by oxidative stress, to promote cancer development, progression, and resistance to chemotherapeutic treatments. Here we review the current literature on the effect of oxidative stress in the epigenetic machinery, especially over the largely unknown ncRNAs and its consequences toward cancer development and progression.