Knockdown of miR-183 Enhances the Cisplatin-Induced Apoptosis in Esophageal Cancer Through Increase of FOXO1 Expression

MicroRNA-183 cluster: a promising biomarker and therapeutic target in gastrointestinal malignancies

Small non-coding RNAs (microRNA, miR), powerful epigenetic regulators, were found involved in the regulation of most biological functions via post-translational inhibition of protein expression. Increased expression of pro-oncogenic miRs (known as miR cancer biomarkers) and inhibition of pro-apoptotic miR expression have been demonstrated in different tumors. The recently identified miR-183 was found implicated in gastrointestinal tumor metabolism regulation. Elevated miR-183 expression and cancer-promoting effects were reported in esophageal and colorectal cancers, which was partially contradicted by controversial data observed in gastric cancers. Anti-cancer effect of miR-183 in gastric cancer cells was associated with the Bim-1 and Ezrin genes regulation. Many studies indicated that miR-183 can inhibit tumor suppressor genes in most cell lines, promoting tumor cell proliferation and migration. Increased miR-183 level results in the downregulation of FOXO1, PDCD4, and other tumor suppressor genes in gastrointestinal tumor cells. MiR-183 also influences the signaling of PI3K/AKT/mTOR, Wnt/β-catenin, and Bcl-2/p53 signaling pathways. Mir-183 inhibits apoptosis and autophagy, and promotes epithelial-to-mesenchymal transition, cancer cell proliferation, and migration. Accordingly, gastrointestinal cancer occurrence, development of chemoradiotherapy resistance, recurrence/metastasis, and prognosis were associated with miR-183 expression. The current study assessed reported miR-183 functions and signaling, providing new insights for the diagnosis and treatment of gastrointestinal malignancies.

The interplay of signaling pathways and miRNAs in the pathogenesis and targeted therapy of esophageal cancer

Globally, esophageal cancer (EC) is the 6th leading cause of cancer-related deaths and the second deadliest gastrointestinal cancer. Multiple genetic and epigenetic factors, such as microRNAs (miRNAs), influence its onset and progression. miRNAs are short nucleic acid molecules that can regulate multiple cellular processes by regulating gene expression. Therefore, EC initiation, progression, apoptosis evasions, invasion capacity, promotion, angiogenesis, and epithelial-mesenchymal transition (EMT) enhancement are associated with miRNA expression dysregulation. Wnt/-catenin signaling, Mammalian target of rapamycin (mTOR)/P-gp, phosphoinositide-3-kinase (PI3K)/AKT/c-Myc, epidermal growth factor receptor (EGFR), and transforming growth factor (TGF)-β signaling are crucial pathways in EC that are controlled by miRNAs. This review was conducted to provide an up-to-date assessment of the role of microRNAs in EC pathogenesis and their modulatory effects on responses to various EC treatment modalities.

MicroRNAs as master regulators of FOXO transcription factors in cancer management

MicroRNAs are critical regulators of the plethora of genes, including FOXO "forkhead" dependent transcription factors, which are bonafide tumour suppressors. The FOXO family members modulate a hub of cellular processes like apoptosis, cell cycle arrest, differentiation, ROS detoxification, and longevity. Aberrant expression of FOXOs in human cancers has been observed due to their down-regulation by diverse microRNAs, which are predominantly involved in tumour initiation, chemo-resistance and tumour progression. Chemo-resistance is a major obstacle in cancer treatment. Over 90% of casualties in cancer patients are reportedly associated with chemo-resistance. Here, we have primarily discussed the structure, functions of FOXO and also their post-translational modifications which influence the activities of these FOXO family members. Further, we have addressed the role of microRNAs in carcinogenesis by regulating the FOXOs at post-transcriptional level. Therefore, microRNAs-FOXO axis can be exploited as a novel cancer therapy. The administration of microRNA-based cancer therapy is likely to be beneficial to curb chemo-resistance in cancers.

Short Linear Motifs Orchestrate Functioning of Human Proteins during Embryonic Development, Redox Regulation, and Cancer

Short linear motifs (SLiMs) are evolutionarily conserved functional modules of proteins that represent amino acid stretches composed of 3 to 10 residues. The biological activities of two short peptide segments of human alpha-fetoprotein (AFP), a major embryo-specific and cancer-related protein, have been confirmed experimentally. This is a heptapeptide segment LDSYQCT in domain I designated as AFP14–20 and a nonapeptide segment EMTPVNPGV in domain III designated as GIP-9. In our work, we searched the UniprotKB database for human proteins that contain SLiMs with sequence similarity to the both segments of human AFP and undertook gene ontology (GO)-based functional categorization of retrieved proteins. Gene set enrichment analysis included GO terms for biological process, molecular function, metabolic pathway, KEGG pathway, and protein–protein interaction (PPI) categories. We identified the SLiMs of interest in a variety of non-homologous proteins involved in multiple cellular processes underlying embryonic development, cancer progression, and, unexpectedly, the regulation of redox homeostasis. These included transcription factors, cell adhesion proteins, ubiquitin-activating and conjugating enzymes, cell signaling proteins, and oxidoreductase enzymes. They function by regulating cell proliferation and differentiation, cell cycle, DNA replication/repair/recombination, metabolism, immune/inflammatory response, and apoptosis. In addition to the retrieved genes, new interacting genes were identified. Our data support the hypothesis that conserved SLiMs are incorporated into non-homologous proteins to serve as functional blocks for their orchestrated functioning.

Antagonistic effect of selenium on mercuric chloride in the central immune organs of chickens: The role of microRNA-183/135b-FOXO1/TXNIP/NLRP3 inflammasome axis

Mercury (Hg) is a persistent environmental and industrial pollutant that accumulated in the body and induces oxidative stress and inflammation damage. Selenium (Se) has been reported to antagonize immune organs damage caused by heavy metals. Here, we aimed to investigate the prevent effect of Se on mercuric chloride (HgCl₂ )-induced thymus and bursa of Fabricius (BF) damage in chickens. The results showed that HgCl₂ caused immunosuppression by reducing the relative weight, cortical area of the thymus and BF, and the number of peripheral blood lymphocytes. Meanwhile, HgCl₂ induced oxidative stress and imbalance in cytokines expression in the thymus and BF. Further, we found that thioredoxin-interacting protein (TXNIP) and the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome mediated HgCl₂ -induced oxidative stress and inflammation. Mechanically, the targeting and inhibitory effect of microRNA (miR)-135b/183 on forkhead box O1 (FOXO1) were an upstream event for HgCl₂ -activated TXNIP/NLRP3 inflammasome pathway. Most importantly, Se effectively attenuated the aforementioned damage in the thymus and BF caused by HgCl₂ and inhibited the TXNIP/NLRP3 inflammasome pathway by reversing the expression of FOXO1 through inhibiting miR-135b/183. In conclusion, the miR-135b/183-FOXO1/TXNIP/NLRP3 inflammasome axis might be a novel mechanism for Se to antagonize HgCl₂ -induced oxidative stress and inflammation in the central immune organs of chickens.

MicroRNA-485-5p inhibits glioblastoma progression by suppressing E2F transcription factor 1 under cisplatin treatment

Cisplatin (CDDP) has been widely used for glioblastoma treatment. miR-485-5p and E2F transcription factor 1 (E2F1) dysfunction has been reported in glioblastoma. Nonetheless, whether CDDP affects glioblastoma progression via the miR-485-5p-E2F1 axis requires investigation. The expression of miR-485-5p and E2F1 was investigated by quantitative real-time polymerase chain reaction or western blotting in glioblastoma tissues and cell lines. The interaction between miR-485-5p and E2F1 was confirmed using a luciferase assay. The malignancy of glioblastoma was detected using Cell Counting Kit-8, bromodeoxyuridine (BrdU), cell adhesion, flow cytometry, and transwell assays. We identified miR-485-5p downregulation and E2F1 upregulation in glioblastoma, and miR-485-5p inhibited cell growth and elevated cell apoptosis in glioblastoma cells after CDDP treatment. Moreover, miR-485-5p targeting E2F1 repressed cell growth and improved cell apoptosis in glioblastoma cells after CDDP treatment. Our study revealed that CDDP retarded glioblastoma cell development via the miR-485-5p-E2F1 axis, which may be a new direction for glioblastoma therapy.

miR-183-5p Promotes HCC Migration/Invasion via Increasing Aerobic Glycolysis

Background

The mortality and morbidity of hepatocellular carcinoma (HCC) are still unacceptably high, despite decades of extensive studies. Aerobic glycolysis is a hallmark of cancer metabolism, closely relating to invasion and metastasis of HCC. MicroRNAs (miRNAs) are involved in the regulation of aerobic glycolysis. miR-183-5p, an oncogenic miRNA, is highly expressed in HCC, but the regulatory mechanism of miR-183-5p in migration, invasion and aerobic glycolysis in HCC remains unclear.

Purpose

To elucidate whether miR-183-5p affects aerobic glycolysis to regulate the migration and invasion of HCC, and to explore its regulatory mechanism.

Methods

We attempted to observe the effects of miR-183-5p on the migration and invasion of HepG2 cells by a wound-healing assay and Transwell assays. The effect of miR-183-5p on glycolysis was determined by glucose uptake and lactate generation. Western blot and qPCR were used to detect the relevant proteins and miRNA expression.

Results

Our results show that miR-183-5p promoted migration and invasion, enhanced glycolysis via increasing glucose uptake and lactate generation, and up-regulated glycolysis-related gene (PKM2, HK2, LDHA, GLUT1) expression in HepG2 cells. Further experiments indicated that miR-183-5p could decrease PTEN expression, but increased Akt, p-Akt and mTOR expression in HepG2 cells.

Conclusion

These findings suggest that miR-183-5p may promote HCC migration and invasion via increasing aerobic glycolysis through targeting PTEN and then activating Akt/mTOR signaling.

miRNAs Involved in Esophageal Carcinogenesis and miRNA-Related Therapeutic Perspectives in Esophageal Carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs that play a pivotal role in many aspects of cell biology, including cancer development. Within esophageal cancer, miRNAs have been proved to be involved in all phases of carcinogenesis, from initiation to metastatic spread. Several miRNAs have been found to be dysregulated in esophageal premalignant lesions, namely Barrett’s esophagus, Barrett’s dysplasia, and squamous dysplasia. Furthermore, numerous studies have investigated the alteration in the expression levels of many oncomiRNAs and tumor suppressor miRNAs in esophageal squamous cell carcinoma and esophageal adenocarcinoma, thus proving how miRNAs are able modulate crucial regulatory pathways of cancer development. Considering these findings, miRNAs may have a role not only as a diagnostic and prognostic tool, but also as predictive biomarker of response to anti-cancer therapies and as potential therapeutic targets. This review aims to summarize several studies on the matter, focusing on the possible diagnostic–therapeutic implications.