MiR-128b is down-regulated in gastric cancer and negatively regulates tumour cell viability by targeting PDK1/Akt/NF-κB axis

Canagliflozin alleviates experimentally induced benign prostate hyperplasia in a rat model: exploring potential mechanisms involving mir-128b/EGFR/EGF and JAK2/STAT3 signaling pathways through in silico and in vivo investigations

Benign prostatic hyperplasia (BPH) poses a significant health concern amongst elderly males. Canagliflozin (Cana), a selective sodium-glucose co-transporter 2 (SGLT2) inhibitor, has a powerful anti-inflammatory influence. Nevertheless, its role in treating BPH has not been clarified. Therefore, the study aimed to investigate the potential ameliorative effect of Cana on experimentally induced BPH in rats and explore the underlying mechanisms compared to the standard finasteride (Fin). The study employed histological analysis, biochemical assays using ELISA, and western blotting. Animals were categorized into four groups: Control (2.5 ml/kg CMC, orally + 3 ml/kg olive oil, subcutaneous), BPH (3 mg/kg testosterone, subcutaneous + CMC orally), Fin-treated BPH (5 mg/kg, orally), and Cana-treated BPH (5 mg/kg, orally), for 28 days. The BPH group showed obvious BPH manifestations including an increase in prostate weight (PW), prostate index (PI), dihydrotestosterone (DHT) level, and histological aberrations compared to control. Fin and Cana therapy had a comparable impact. Cana treatment significantly reduced PW and PI, besides it improved prostatic biochemical, and histopathological features compared to BPH, consistent with in silico study findings. Cana was associated with downregulation of the androgen axis, increased miR-128b expression, with a lowered expression of epidermal growth factor (EGF) and its receptor. Phosphorylation of STAT3 and its downstream proliferative markers were significantly reduced suggesting apoptotic activity. Cana markedly rescued the BPH-induced upregulation of IL-1β, and iNOS levels. Altogether, the current study demonstrates that Cana could impede BPH progression, possibly by modulating miR-128b/EGFR/EGF and JAK2/STAT3 pathways and downregulating AR, cyclin D1, and PCNA immunoreactivity.

The role of miR-128 in cancer development, prevention, drug resistance, and immunotherapy

A growing body of evidence has revealed that microRNA (miRNA) expression is dysregulated in cancer, and they can act as either oncogenes or suppressors under certain conditions. Furthermore, some studies have discovered that miRNAs play a role in cancer cell drug resistance by targeting drug-resistance-related genes or influencing genes involved in cell proliferation, cell cycle, and apoptosis. In this regard, the abnormal expression of miRNA-128 (miR-128) has been found in various human malignancies, and its verified target genes are essential in cancer-related processes, including apoptosis, cell propagation, and differentiation. This review will discuss the functions and processes of miR-128 in multiple cancer types. Furthermore, the possible involvement of miR-128 in cancer drug resistance and tumor immunotherapeutic will be addressed.

The role of miRNA-128 in the development and progression of gastrointestinal and urogenital cancer

Increasing data have shown the significance of various miRNAs in malignancy. In this regard, parallel to its biological role in normal tissues, miRNA-128 (miR-128) has been found to play an essential immunomodulatory function in the process of cancer initiation and development. The occurrence of the aberrant expression of miR-128 in tumors and the unique properties of miRNAs raise the prospect of their use as biomarkers and the next generation of molecular anticancer therapies. The function of miR-128 in malignancies such as breast, prostate, colorectal, gastric, pancreatic, esophageal, cervical, ovarian and bladder cancers and hepatocellular carcinoma is discussed in this review. Finally, the effect of exosomal miR-128 on cancer resistance to therapeutics and cancer immunotherapy in certain malignancies is highlighted.

microRNA-128-3p inhibits CD4+ regulatory T cells enrichment by targeting interleukin 16 in gastric cancer

Previous studies have confirmed that microRNA (miR)-128-3p is expressed at low levels in gastric cancer (GC), and low miR-128-3p expression promotes the growth of GC cells. However, whether the dysregulation of miR-128-3p expression affects tumor-infiltrating lymphocytes (TILs) and leads to immune escape remains unclear. In the present study, predictive bioinformatics approaches showed that miR-128-3p expression was inversely correlated with tumor-infiltrating lymphocyte enrichment. When CD4 + T cells and regulatory T cells (Tregs) were enriched, lower miR-128-3p expression was associated with worse overall survival. However, when numbers of CD8 + T cells were decreased, the upregulation of miR-128-3p expression had a favorable effect on GC prognosis. Dual-luciferase reporter assays and cell biology experiments revealed that interleukin 16 (IL16) was the target of miR-128-3p and was negatively regulated by miR-128-3p. In addition, GC cells were cocultured with T lymphocytes, and the subsequent flow cytometric analysis showed that overexpression of miR-128-3p in tumor cells decreased the percentages of CD4+ CD25+ Foxp3+ Tregs by downregulating IL16 expression in GC, whereas miR-128-3p inhibition had the opposite effect. Moreover, the recombinant IL16 reversed the effects of miR-128-3p overexpression, and a competitive antibody against the IL16 receptor CD4 also reversed the effects of miR-128-3p knockdown. These studies identified the mechanism by which the miR-128-3p/IL16 axis promotes the infiltration of CD4+ Tregs in GC, and this mechanism will be a promising therapeutic target in GC immunotherapy.

Cascades between miRNAs, lncRNAs and the NF-κB signaling pathway in gastric cancer (Review)

Gastric cancer is a common digestive tract malignancy that is mainly treated with surgery combined with perioperative adjuvant chemoradiotherapy and biological targeted therapy. However, the diagnosis rate of early gastric cancer is low and both postoperative recurrence and distant metastasis are thorny problems. Therefore, it is essential to study the pathogenesis of gastric cancer and search for more effective means of treatment. The nuclear factor-κB (NF-κB) signaling pathway has an important role in the occurrence and development of gastric cancer and recent studies have revealed that microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are able to regulate this pathway through a variety of mechanisms. Understanding these interrelated molecular mechanisms is helpful in guiding improvements in gastric cancer treatment. In the present review, the functional associations between miRNAs, lncRNAs and the NF-κB signaling pathway in the occurrence, development and prognosis of gastric cancer were discussed. It was concluded that miRNAs and lncRNAs have complex relations with the NF-κB signaling pathway in gastric cancer. miRNAs/target genes/NF-κB/target proteins, signaling molecules/NF-κB/miRNAs/target genes, lncRNAs/miRNAs/NF-κB/genes or mRNAs, lncRNAs/target genes/NF-Κb/target proteins, and lncRNAs/NF-κB/target proteins cascades are all important factors in the occurrence and development of gastric cancer.

Regulation of Nuclear Factor-KappaB (NF-κB) signaling pathway by non-coding RNAs in cancer: Inhibiting or promoting carcinogenesis?

The nuclear factor-kappaB (NF-κB) signaling pathway is considered as a potential therapeutic target in cancer therapy. It has been well established that transcription factor NF-κB is involved in regulating physiological and pathological events including inflammation, immune response and differentiation. Increasing evidences suggest that deregulated NF-κB signaling can enhance cancer cell proliferation, metastasis and also mediate radio-as well as chemo-resistance. On the contrary, non-coding RNAs (ncRNAs) have been found to modulate NF-κB signaling pathway under different settings. MicroRNAs (miRNAs) can dually inhibit/induce NF-κB signaling thereby affecting the growth and migration of cancer cells. Furthermore, the response of cancer cells to radiotherapy and chemotherapy may also be regulated by miRNAs. Regulation of NF-κB by miRNAs may be mediated via binding to 3^/-UTR region. Interestingly, anti-tumor compounds can increase the expression of tumor-suppressor miRNAs in inhibiting NF-κB activation and the progression of cancers. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) can also effectively modulate NF-κB signaling thus affecting tumorigenesis. It is noteworthy that several studies have demonstrated that lncRNAs and circRNAs can affect miRNAs in targeting NF-κB activation. They can act as competing endogenous RNA (ceRNA) thereby reducing miRNA expression to induce NF-κB activation that can in turn promote cancer progression and malignancy.

DLX6 Antisense RNA 1 Modulates Glucose Metabolism and Cell Growth in Gastric Cancer by Targeting microRNA-4290

BACKGROUND

Gastric cancer (GC) is one of the most commonly diagnosed malignancy worldwide. DLX6 antisense RNA 1 (DLX6-AS1) is a long noncoding RNA (lncRNA) that exhibits oncogenic effects on multiple human carcinomas.

AIMS

This study aimed to investigate the regulatory effect of DLX6-AS1 in GC progression.

METHODS

The expression of DLX6-AS1 in GC tissues and cell lines was examined. The cell viability, number of clones, and apoptosis, aerobic glycolysis, and mitochondrial respiration was assessed. The effect of DLX6-AS1 on tumor growth in nude mice was also evaluated.

RESULTS

DLX6-AS1 was overexpressed in GC tissues and cell lines. DLX6-AS1 knockdown by short hairpin RNA (shRNA) significantly inhibited cell viability and colony formation, and induced apoptosis. DLX6-AS1 silencing impaired aerobic glycolysis but stimulated mitochondrial respiration in GC cells. miR-4290 was confirmed as a downstream target of DLX6-AS1, and their expression levels were inversely correlated. GC cells expressing sh-DLX6-AS1 showed significantly lower level of 3-phosphoinositide-dependent protein kinase 1 (PDK1), a target of miR-4290, compared to cells expressing control shRNA. In addition, the suppressed GC cell malignancy upon DLX6-AS1 knockdown could be prominently reversed by PDK1 overexpression. Meanwhile, PDK1 overexpression enhanced aerobic glycolysis but repressed mitochondrial respiration under sh-DLX6-AS1 treatment. Furthermore, DLX6-AS1 knockdown significantly delayed the tumor growth in a mouse xenograft model inoculated with GC cells.

CONCLUSIONS

LncRNA DLX6-AS1 regulated tumor growth and aerobic glycolysis in GC by targeting miR-4290 and PDK1, suggesting DLX6-AS1 might serve as a novel potential therapeutic target for GC treatment from bench to clinic.

MicroRNA in Gastric Cancer Development: Mechanisms and Biomarkers

Gastric cancer (GC) is one of the most common and difficult diseases to treat. The study of signaling pathway regulation by microRNA provides information on the mechanisms of GC development and is the basis for biomarker creation. In this study, a circuit of microRNA interactions with signaling pathways was constructed. The microRNAs, associated with metastasis and chemoresistance, are described. In most cases, microRNAs in GC regulate the Wnt/β-catenin, PI3K/AKT/mTOR, RAS/RAF/ERK/MAPK, NF-kB, TGF-β, and JAK/STAT pathways. Part of the microRNA acts on several target genes that function in different pathways. This often leads to an intensification of the induced processes. MicroRNAs have also been described that have the opposite effect on different pathways, causing different functional consequences. By acting on several target genes, or genes associated with several pathways, microRNAs can function in a signaling network. MicroRNAs associated with metastasis most often interact with the Wnt/β-catenin pathway. MicroRNAs affecting chemoresistance, in most cases, affect the regulators of apoptosis and are associated with the PI3K/AKT/mTOR pathway. The characteristics of microRNAs proposed as candidates for GC biomarkers were analyzed. The currently developed diagnostic and prognostic panels of microRNAs are also considered.

MicroRNAs in gastric cancer: Biomarkers and therapeutic targets

MicroRNAs (miRNAs) are a group of non-coding RNAs that have critical roles in regulation of expression of genes. They can inhibit or decrease expression of target genes mostly via interaction with 3' untranslated region of their targets. Their crucial roles in the regulation of expression of tumor suppressor genes and oncogenes have potentiated them as contributors in tumorigenesis. Moreover, their stability in body fluids has enhanced their potential as cancer biomarkers. In the present review article, we describe the role of miRNAs in the pathogenesis of gastric cancer and advances in application of miRNAs as biomarkers and therapeutic targets in this kind of malignancy.

Metabolic reprogramming results in abnormal glycolysis in gastric cancer: a review

The Warburg effect in tumor cells involves the uptake of high levels of glucose, enhanced glycolysis, and the metabolism of pyruvate to lactic acid rather than oxidative phos-phorylation to generate energy under aerobic conditions. This effect is closely related to the occurrence, invasion, metastasis, drug resistance, and poor prognosis of gastric cancer (GC). Current research has further demonstrated that the Warburg effect in GC cells is not only mediated by the glycolysis pathway, but also includes roles for mitochondria, noncoding RNAs, and other proteins that do not directly regulate metabolism. As a result, changes in the glycolysis pathway not only lead to abnormal glucose metabolism, but they also affect mitochondrial functions, cellular processes such as apoptosis and cell cycle regulation, and the metabolism of lipids and amino acids. In this review, we discuss metabolic reprogramming in GC based on glycolysis, a possible link between glucose metabolism, lipid metabolism, and amino acid metabolism, and we clarify the role of mitochondria. We also examine recent studies of metabolic inhibitors in GC.

Phosphoinositide-dependent kinase 1-associated glycolysis is regulated by miR-409-3p in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most popular kidney cancer in adults. Metabolic shift toward aerobic glycolysis is a fundamental factor for ccRCC therapy. MicroRNAs (miRNAs) are thought to be important regulators in ccRCC development and progression. Phosphoinositide-dependent kinase 1 (PDK1) is required for metabolic activation; however, the role of PDK1-induced glycolytic metabolism regulated by miRNAs is unclear in ccRCC. So, the purpose of the current study is to elucidate the underlying mechanism in ccRCC cell metabolism mediated by PDK1. Our results revealed that miR-409-3p inhibited glycolysis by regulating PDK1 expression in ccRCC cells. We also found that miR-409-3p was regulated by hypoxia. Our results indicated that PDK1 facilitated ccRCC cell glycolysis, regulated by miR-409-3p in hypoxia.

Editor’s Pick: Pyruvate Kinase and Gastric Cancer: A Potential Marker

Gastric cancer is the second most common cause of cancer-related deaths worldwide, and the 5-year overall survival rate for advanced gastric cancer is ≤25%. Metabolism is a critical process for maintaining growth and other functions in cancer cells; in these cells, the metabolic process shifts from oxidative phosphorylation to aerobic glycolysis and the expression of pyruvate kinase (PK) splice isoform M2 (PKM2) is upregulated. A PubMed search focussing on PK in gastric cancer was conducted and 32 articles were initially collected; 12 articles were subsequently excluded from this review. PKM2 is responsible for tumour growth and invasion and correlates with short survival times and cancer differentiation. Pyruvate dehydrogenase kinase 1 is associated with cell proliferation, lymph node metastasis, and invasion. Measurement of PKM2 or pyruvate dehydrogenase kinase 1 in the blood or stools could be a good marker for gastric cancer in combination with the glycoprotein CA72-4. The review arose from the need for new biomarkers in the management of gastric cancer and had the primary objective of determining whether PK could be used as a marker to diagnose and monitor gastric cancer.

PDK1 governs thromboxane generation and thrombosis in platelets by regulating activation of Raf1 in the MAPK pathway

Essentials Phosphoinositide 3-kinase and MAPK pathways crosstalk via PDK1. PDK1 is required for adenosine diphosphate-induced platelet activation and thromboxane generation. PDK1 regulates RAF proto-oncogene Ser/Thr kinase (Raf1) activation in the MAPK pathway. Genetic ablation of PDK1 protects against platelet-dependent thrombosis in vivo.

SUMMARY

Background Platelets are dynamic effector cells with functions that span hemostatic, thrombotic and inflammatory continua. Phosphoinositide-dependent protein kinase 1 (PDK1) regulates protease-activated receptor 4-induced platelet activation and thrombus formation through glycogen synthase kinase3β. However, whether PDK1 also signals through the ADP receptor and its functional importance in vivo remain unknown. Objective To establish the mechanism of PDK1 in ADP-induced platelet activation and thrombosis. Methods We assessed the role of PDK1 on 2MeSADP-induced platelet activation by measuring aggregation, thromboxane generation and phosphorylation events in the presence of BX-795, which inhibits PDK1, or by using platelet-specific PDK1 knockout mice and performing western blot analysis. PDK1 function in thrombus formation was assessed with an in vivo pulmonary embolism model. Results PDK1 inhibition with BX-795 reduced 2-methylthio-ADP (2MeSADP)-induced aggregation of human and murine platelets by abolishing thromboxane generation. Similar results were observed in pdk1-/- mice. PDK1 was also necessary for the phosphorylation of mitogen-activated protein kinase kinase 1/2 (MEK1/2), extracellular signal-regulated kinase 1/2, and cytosolic phospholipase A2, indicating that PDK1 regulates an upstream kinase in the mitogen-activated protein kinase (MAPK) pathway. We next determined that this upstream kinase is Raf-1, a serine/threonine kinase that is necessary for the phosphorylation of MEK1/2, as pharmacological inhibition and genetic ablation of PDK1 were sufficient to prevent Raf1 phosphorylation. Furthermore, in vivo inhibition or genetic ablation of PDK1 protected mice from collagen/epinephrine-induced pulmonary embolism. Conclusion PDK1 governs thromboxane generation and thrombosis in platelets that are stimulated with 2MeSADP by regulating activation of the MAPK pathway.

NF-κB Signaling in Gastric Cancer

Gastric cancer is a leading cause of cancer death worldwide. Diet, obesity, smoking and chronic infections, especially with Helicobacter pylori, contribute to stomach cancer development. H. pylori possesses a variety of virulence factors including encoded factors from the cytotoxin-associated gene pathogenicity island (cagPAI) or vacuolating cytotoxin A (VacA). Most of the cagPAI-encoded products form a type 4 secretion system (T4SS), a pilus-like macromolecular transporter, which translocates CagA into the cytoplasm of the host cell. Only H. pylori strains carrying the cagPAI induce the transcription factor NF-κB, but CagA and VacA are dispensable for direct NF-κB activation. NF-κB-driven gene products include cytokines/chemokines, growth factors, anti-apoptotic factors, angiogenesis regulators and metalloproteinases. Many of the genes transcribed by NF-κB promote gastric carcinogenesis. Since it has been shown that chemotherapy-caused cellular stress could elicit activation of the survival factor NF-κB, which leads to acquisition of chemoresistance, the NF-κB system is recommended for therapeutic targeting. Research is motivated for further search of predisposing conditions, diagnostic markers and efficient drugs to improve significantly the overall survival of patients. In this review, we provide an overview about mechanisms and consequences of NF-κB activation in gastric mucosa in order to understand the role of NF-κB in gastric carcinogenesis.

Serine/Threonine Kinase 3-Phosphoinositide-Dependent Protein Kinase-1 (PDK1) as a Key Regulator of Cell Migration and Cancer Dissemination

Dissecting the cellular signaling that governs the motility of eukaryotic cells is one of the fundamental tasks of modern cell biology, not only because of the large number of physiological processes in which cell migration is crucial, but even more so because of the pathological ones, in particular tumor invasion and metastasis. Cell migration requires the coordination of at least four major processes: polarization of intracellular signaling, regulation of the actin cytoskeleton and membrane extension, focal adhesion and integrin signaling and contractile forces generation and rear retraction. Among the molecular components involved in the regulation of locomotion, the phosphatidylinositol-3-kinase (PI3K) pathway has been shown to exert fundamental role. A pivotal node of such pathway is represented by the serine/threonine kinase 3-phosphoinositide-dependent protein kinase-1 (PDPK1 or PDK1). PDK1, and the majority of its substrates, belong to the AGC family of kinases (related to cAMP-dependent protein kinase 1, cyclic Guanosine monophosphate-dependent protein kinase and protein kinase C), and control a plethora of cellular processes, downstream either to PI3K or to other pathways, such as RAS GTPase-MAPK (mitogen-activated protein kinase). Interestingly, PDK1 has been demonstrated to be crucial for the regulation of each step of cell migration, by activating several proteins such as protein kinase B/Akt (PKB/Akt), myotonic dystrophy-related CDC42-binding kinases alpha (MRCKα), Rho associated coiled-coil containing protein kinase 1 (ROCK1), phospholipase C gamma 1 (PLCγ1) and β3 integrin. Moreover, PDK1 regulates cancer cell invasion as well, thus representing a possible target to prevent cancer metastasis in human patients. The aim of this review is to summarize the various mechanisms by which PDK1 controls the cell migration process, from cell polarization to actin cytoskeleton and focal adhesion regulation, and finally, to discuss the evidence supporting a role for PDK1 in cancer cell invasion and dissemination.