MicroRNA-21 induces loss of 15-hydroxyprostaglandin dehydrogenase in early gastric tubular adenocarcinoma

CRISPR/Cas9 Genome-Editing Technology and Potential Clinical Application in Gastric Cancer

Gastric cancer is the subject of clinical and basic studies due to its high incidence and mortality rates worldwide. Due to the diagnosis occurring in advanced stages and the classic treatment methodologies such as gastrectomy and chemotherapy, they are extremely aggressive and limit the quality of life of these patients. CRISPR/Cas9 is a tool that allows gene editing and has been used to explore the functions of genes related to gastric cancer, in addition to being used in the treatment of this neoplasm, greatly increasing our understanding of cancer genomics. In this mini-review, we seek the current status of the CRISPR/Cas9 gene-editing technology in gastric cancer research and clinical research.

Exploration of Potential Ewing Sarcoma Drugs from FDA-Approved Pharmaceuticals through Computational Drug Repositioning, Pharmacogenomics, Molecular Docking, and MD Simulation Studies

Novel drug development is a time-consuming process with relatively high debilitating costs. To overcome this problem, computational drug repositioning approaches are being used to predict the possible therapeutic scaffolds against different diseases. In the current study, computational drug repositioning approaches were employed to fetch the promising drugs from the pool of FDA-approved drugs against Ewing sarcoma. The binding interaction patterns and conformational behaviors of screened drugs within the active region of Ewing sarcoma protein (EWS) were confirmed through molecular docking profiles. Furthermore, pharmacogenomics analysis was employed to check the possible associations of selected drugs with Ewing sarcoma genes. Moreover, the stability behavior of selected docked complexes (drugs-EWS) was checked by molecular dynamics simulations. Taken together, astemizole, sulfinpyrazone, and pranlukast exhibited a result comparable to pazopanib and can be used as a possible therapeutic agent in the treatment of Ewing sarcoma.

Macrophage-Derived MicroRNA-21 Drives Overwhelming Glycolytic and Inflammatory Response during Sepsis via Repression of the PGE2/IL-10 Axis

Myeloid cells are critical for systemic inflammation, microbial control, and organ damage during sepsis. MicroRNAs are small noncoding RNAs that can dictate the outcome of sepsis. The role of myeloid-based expression of microRNA-21 (miR-21) in sepsis is inconclusive. In this study, we show that sepsis enhanced miR-21 expression in both peritoneal macrophages and neutrophils from septic C57BL/6J mice, and the deletion of miR-21 locus in myeloid cells (miR-21^Δmyel mice) enhanced animal survival, decreased bacterial growth, decreased systemic inflammation, and decreased organ damage. Resistance to sepsis was associated with a reduction of aerobic glycolysis and increased levels of the anti-inflammatory mediators PGE₂ and IL-10 in miR-21^Δmyel in vivo and in vitro. Using blocking Abs and pharmacological tools, we discovered that increased survival and decreased systemic inflammation in septic miR-21^Δmyel mice is dependent on PGE₂/IL-10-mediated inhibition of glycolysis. Together, these findings demonstrate that expression of miR-21 in myeloid cells orchestrates the balance between anti-inflammatory mediators and metabolic reprogramming that drives cytokine storm during sepsis.

Original Article: MicroRNA Dysregulation in the Gastric Carcinogenesis Cascade: Can We Anticipate Its Role in Individualized Care?

BACKGROUND

Gastric carcinogenesis progresses from normal mucosa, atrophic/metaplastic gastritis, and dysplasia to adenocarcinoma. MicroRNAs (miRNAs) regulate DNA expression and have been implicated; however, their role is not fully established.

AIMS

The aim of this study was to characterize plasma and tissue expression of several miRNAs in gastric carcinogenesis stages.

METHODS

Single-center cross-sectional study in 64 patients: 19 controls (normal mucosa); 15 with extensive atrophic/metaplastic gastritis; and 30 with early gastric neoplasia (EGN). Seven miRNAs (miR-21, miR-146a, miR-181b, miR-370, miR-375, miR 181b, and miR-490) were quantified by real time-qPCR in peripheral blood and endoscopic biopsy samples.

RESULTS

We found a significant upregulation of miR-181b, miR-490, and miR-21 in the EGN mucosa (overexpression 2-14-times higher than controls). We observed a significant underexpression of miR-146a and miR-370 in atrophic/metaplastic gastritis (86 and 66% decrease, p = 0.008 and p = 0.001) and in EGN (89 and 62% reduction, p = 0.034 and p = 0.032) compared with controls. There were no differences between lesions and nonneoplastic mucosa and no dysregulation of plasma miRNAs.

CONCLUSION

We found significant dysregulation of 5 miRNAs in gastric carcinogenesis, suggesting a tumor suppressor role for miR-146a and miR-370 and oncogenic potential for miR-21, miR-181, and miR-490. These changes happen diffusely in the gastric mucosa, suggesting a high-risk field defect, which may influence these patients' surveillance.

Anti-Inflammatory Effects of Heat-Processed Artemisia capillaris Thunberg by Regulating IκBα/NF-κB Complex and 15-PGDH in Mouse Macrophage Cells

Growing evidence suggests that dietary nutrients in herbs and plants are beneficial in improving inflammatory disorders. Artemisia capillaris Thunberg (AC) is a traditional herbal medicine widely used in East Asia to treat pain, hepatotoxicity, and inflammatory disorders. Heat processing is a unique pharmaceutical method used in traditional herbal medicine to enhance the pharmacological effects and safety of medicinal plants. This study demonstrates the anti-inflammatory effects of heat-processed AC (HPAC) in lipopolysaccharide- (LPS-) treated mouse macrophage cells. HPAC reduced LPS-induced inflammatory mediators such as IL-6, IL-1β, TNF-α, NO, and PGE2 in RAW 264.7 cells. Interestingly, 15-PGDH appears to play a pivotal role rather than COX-2 and mPGES-1 when HPAC regulated PGE2 levels. Meanwhile, HPAC showed anti-inflammatory effects by blocking IκBα phosphorylation and NF-κB nuclear translocalization. Also, we found that HO-1 upregulation was mediated by the mitogen-activated protein kinase (MAPK) pathways in HPAC-treated RAW 264.7 cells. And, in RAW 264.7 cells challenged with LPS, HPAC restored HO-1 expression, leading to NF-κB inhibition. Through further experiments using specific MAPK inhibitors, we found that, in response to LPS, the phosphorylated IκBα and activated NF-κB were attenuated by p38 MAPK/HO-1 pathway. Therefore, HPAC targeting both the IκBα/NF-κB complex and 15-PGDH may be considered as a potential novel anti-inflammatory agent derived from a natural source.

Overview on the Discovery and Development of Anti-Inflammatory Drugs: Should the Focus Be on Synthesis or Degradation of PGE2?

Inflammation is a protective response that develops against tissue injury and infection. Chronic inflammation, on the other hand, is the key player in the pathogenesis of many inflammatory disorders including cancer. The cytokine storm, an inflammatory response flaring out of control, is mostly responsible for the mortality in COVID-19 patients. Anti-inflammatory drugs inhibit cyclooxygenases (COX), which are involved in the biosynthesis of prostaglandins that promote inflammation. The conventional non-steroidal anti-inflammatory drugs (NSAIDs) are associated with gastric and renal side-effects, as they inhibit both the constitutive COX-1 and the inducible COX-2. The majority of selective COX-2 inhibitors (COXIBs) are without gastric side-effects but are associated with cardiac side-effects on long-term use. The search for anti-inflammatory drugs without side-effects, therefore, has become a dream and ongoing effort of the Pharma companies. As PGE₂ is the key mediator of inflammatory disorders, coming up with a strategy to reduce the levels of PGE₂ alone without affecting other metabolites may form a better choice for the development of next generation anti-inflammatory drugs. In this direction the options being explored are on synthesis of PGE₂-mPGES-1; PGE₂ degradation through a specific PG dehydrogenase, 15-PGDH, and by blocking its activity mediated through a specific PGE receptor, EP4. As leukotrienes formed via the 5-lipoxygenase (5-LOX) pathway also play an important role in the mediation of inflammation, efforts are also being made to target both COX and LOX pathways. This review focuses on addressing the following three points: 1) How NSAIDs and COXIBs are associated with gastric, renal and cardiac side-effects; 2) Should the focus be on the targets upstream or downstream of PGE₂; and 3) the status of alternative targets being explored for the discovery and development of anti-inflammatory drugs without side-effects.

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miR-21-mediated regulation of 15-hydroxyprostaglandin dehydrogenase in colon cancer

Elevated prostaglandin E₂ (PGE₂) levels are observed in colorectal cancer (CRC) patients, and this increase is associated with poor prognosis. Increased synthesis of PGE₂ in CRC has been shown to occur through COX-2-dependent mechanisms; however, loss of the PGE₂-catabolizing enzyme, 15-hydroxyprostaglandin dehydrogenase (15-PGDH, HPGD), in colonic tumors contributes to increased prostaglandin levels and poor patient survival. While loss of 15-PGDH can occur through transcriptional mechanisms, we demonstrate that 15-PGDH can be additionally regulated by a miRNA-mediated mechanism. We show that 15-PGDH and miR-21 are inversely correlated in CRC patients, with increased miR-21 levels associating with low 15-PGDH expression. 15-PGDH can be directly regulated by miR-21 through distinct sites in its 3′ untranslated region (3′UTR), and miR-21 expression in CRC cells attenuates 15-PGDH and promotes increased PGE₂ levels. Additionally, epithelial growth factor (EGF) signaling suppresses 15-PGDH expression while simultaneously enhancing miR-21 levels. miR-21 inhibition represses CRC cell proliferation, which is enhanced with EGF receptor (EGFR) inhibition. These findings present a novel regulatory mechanism of 15-PGDH by miR-21, and how dysregulated expression of miR-21 may contribute to loss of 15-PGDH expression and promote CRC progression via increased accumulation of PGE₂.