miR-502-5p inhibits the proliferation, migration and invasion of gastric cancer cells by targeting SP1

Regulation of the Lewis Blood Group Antigen Expression: A Literature Review Supplemented with Computational Analysis

Background

The Lewis (Le) blood group system, unlike most other blood groups, is not defined by antigens produced internally to the erythrocytes and their precursors but rather by glycan antigens adsorbed on to the erythrocyte membrane from the plasma. These oligosaccharides are synthesized by the two fucosyltransferases FUT2 and FUT3 mainly in epithelial cells of the digestive tract and transferred to the plasma. At their place of synthesis, some Lewis blood group carbohydrate antigen variants also seem to be involved in various gastrointestinal malignancies. However, relatively little is known about the transcriptional regulation of FUT2 and FUT3.

Summary

To address this question, we screened existing literature and additionally used in silico prediction tools to identify novel candidate regulators for FUT2 and FUT3 and combine these findings with already known data on their regulation. With this approach, we were able to describe a variety of transcription factors, RNA binding proteins and microRNAs, which increase FUT2 and FUT3 transcription and translation upon interaction.

Key Messages

Understanding the regulation of FUT2 and FUT3 is crucial to fully understand the blood group system Lewis (ISBT 007 LE) phenotypes, to shed light on the role of the different Lewis antigens in various pathologies, and to identify potential new diagnostic targets for these diseases.

Lipoic acid alters the microRNA signature in breast cancer cells

BACKGROUND

Breast cancer, the deadliest disease affecting women globally, exhibits heterogeneity with distinct molecular subtypes. Despite advances in cancer therapy, the persistence of high mortality rates due to chemotherapy resistance remains a major challenge. Lipoic acid (LA), a natural antioxidant, has proven potent anticancer properties. Yet, the impact of LA on microRNA (miRNA) expression profile in breast cancer remains unexplored.

AIM

The aim of this study was to unravel the effect of LA on miRNA expression profiles in different breast cancer cell lines.

METHODS

The MiRCURY LNA miRNA miRNome qPCR Panel was used to compare the miRNA signature in MDA-MB-231 and MCF-7 cells treated or not with LA.

RESULTS

We identified six upregulated and six downregulated miRNAs in LA-treated MDA-MB-231 cells and 14 upregulated and four downregulated miRNAs in LA-treated MCF-7 cells compared to control cells. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis revealed that the deregulated miRNAs could alter different signaling cascades including FoxO, P53 and Hippo pathways.

CONCLUSION

The outcome of this study provides further insights into the molecular mechanisms underlying the therapeutic benefit of LA. This in turn could assist the amelioration of LA-based anticancer therapies.

Recent Advances in Extracellular Vesicles in Amyotrophic Lateral Sclerosis and Emergent Perspectives

Amyotrophic lateral sclerosis (ALS) is a severe and incurable neurodegenerative disease characterized by the progressive death of motor neurons, leading to paralysis and death. It is a rare disease characterized by high patient-to-patient heterogeneity, which makes its study arduous and complex. Extracellular vesicles (EVs) have emerged as important players in the development of ALS. Thus, ALS phenotype-expressing cells can spread their abnormal bioactive cargo through the secretion of EVs, even in distant tissues. Importantly, owing to their nature and composition, EVs' formation and cargo can be exploited for better comprehension of this elusive disease and identification of novel biomarkers, as well as for potential therapeutic applications, such as those based on stem cell-derived exosomes. This review highlights recent advances in the identification of the role of EVs in ALS etiopathology and how EVs can be promising new therapeutic strategies.

MicroRNA Alterations Induced in Human Skin by Diesel Fumes, Ozone, and UV Radiation

Epigenetic alterations are a driving force of the carcinogenesis process. MicroRNAs play a role in silencing mutated oncogenes, thus defending the cell against the adverse consequences of genotoxic damages induced by environmental pollutants. These processes have been well investigated in lungs; however, although skin is directly exposed to a great variety of environmental pollutants, more research is needed to better understand the effect on cutaneous tissue. Therefore, we investigated microRNA alteration in human skin biopsies exposed to diesel fumes, ozone, and UV light for over 24 h of exposure. UV and ozone-induced microRNA alteration right after exposure, while the peak of their deregulations induced by diesel fumes was reached only at the end of the 24 h. Diesel fumes mainly altered microRNAs involved in the carcinogenesis process, ozone in apoptosis, and UV in DNA repair. Accordingly, each tested pollutant induced a specific pattern of microRNA alteration in skin related to the intrinsic mechanisms activated by the specific pollutant. These alterations, over a short time basis, reflect adaptive events aimed at defending the tissue against damages. Conversely, whenever environmental exposure lasts for a long time, the irreversible alteration of the microRNA machinery results in epigenetic damage contributing to the pathogenesis of inflammation, dysplasia, and cancer induced by environmental pollutants.

Oncogenic Role of Exosomal Circular and Long Noncoding RNAs in Gastrointestinal Cancers

Circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) are differentially expressed in gastrointestinal cancers. These noncoding RNAs (ncRNAs) regulate a variety of cellular activities by physically interacting with microRNAs and proteins and altering their activity. It has also been suggested that exosomes encapsulate circRNAs and lncRNAs in cancer cells. Exosomes are then discharged into the extracellular environment, where they are taken up by other cells. As a result, exosomal ncRNA cargo is critical for cell-cell communication within the cancer microenvironment. Exosomal ncRNAs can regulate a range of events, such as angiogenesis, metastasis, immune evasion, drug resistance, and epithelial-to-mesenchymal transition. To set the groundwork for developing novel therapeutic strategies against gastrointestinal malignancies, a thorough understanding of circRNAs and lncRNAs is required. In this review, we discuss the function and intrinsic features of oncogenic circRNAs and lncRNAs that are enriched within exosomes.

Circ_0005875 sponges miR-502-5p to promote renal cell carcinoma progression through upregulating E26 transformation specific-1

Increasing evidence has shown that circular RNAs (circRNAs) play critical roles in various cancers, including renal cell carcinoma (RCC). We aimed to explore the role and underlying mechanism of circ_0005875 in RCC. The expression levels of circ_0005875, microRNA-502-5p (miR-502-5p) and E26 transformation specific-1 (ETS1) mRNA were determined by quantitative real-time PCR. Cell proliferation was assessed by Cell Counting Kit-8, colony formation, and 5-Ethynyl-2'-deoxyuridine (EdU) assays. Cell migration and invasion were monitored by wound healing assay and transwell assay, respectively. Flow cytometry analysis was applied to determine cell apoptosis and cell cycle distribution. Western blot assay was performed to measure the protein expression of CyclinD1 and ETS1. The interaction between miR-502-5p and circ_0005875 or ETS1 was confirmed by dual-luciferase reporter and RNA immunoprecipitation assays. A xenograft tumor model was established to confirm the role of circ_0005875 in vivo. Circ_0005875 and ETS1 were upregulated and miR-502-5p was downregulated in RCC tissues and cells. Knockdown of circ_0005875 suppressed RCC cell proliferation, migration and invasion, and induced apoptosis and cell cycle arrest. MiR-502-5p was a target of circ_0005875, and miR-502-5p inhibition reversed the inhibitory effects of circ_0005875 knockdown on the malignant behaviors of RCC cells. ETS1 was a direct target of miR-502-5p, and miR-502-5p exerted its anti-tumor role in RCC cells by targeting ETS1. Moreover, circ_0005875 knockdown decreased ETS1 expression by sponging miR-502-5p. Additionally, circ_0005875 depletion suppressed tumor growth in vivo. Circ_0005875 knockdown suppressed RCC progression by regulating miR-502-5p/ETS1 axis, which might provide a promising therapeutic target for RCC.

Specificity protein 1-activated bone marrow stromal cell antigen 2 accelerates pancreatic cancer cell proliferation and migration

Bone marrow stromal cell antigen 2 (BST2) has been reported to act as an oncogene in the tumorigenesis of numerous types of cancer. Bioinformatics analysis has predicted the binding interaction between BST2 and specificity protein 1 (SP1) and the involvement of SP1 in pancreatic cancer. Therefore, the present study set out to verify this interaction and determine how it may affect pancreatic cancer progression. Normal human pancreatic duct epithelial cells (HPDE6-C7) and pancreatic cancer cell lines (SW1990, BxPC3, PANC1 and PSN-1) were selected for western blotting and reverse transcription-quantitative PCR detection of BST2 expression. Colony formation, Cell Counting Kit-8 and wound healing assays were performed to detect the proliferative and migratory abilities of PANC1 cells following transfection with small interfering RNA against BST2. The expression of proliferation and migration markers were assayed using western blotting. Chromatin immunoprecipitation and luciferase reporter assays were employed to verify the bioinformatics prediction of BST2-SP1 binding. PANC1 cell proliferation and migration were analyzed following BST2 knockdown and SP1 overexpression. In comparison with HPDE6-C7 cells, all four pancreatic cancer cell lines were found to exhibit increased BST2 expression levels to varying degrees, with the highest levels observed in PANC1 cells. BST2 knockdown inhibited PANC1 cell colony formation, proliferation and migration. Additionally, SP1 was shown to bind to the BST2 promoter and could promote PANC1 cell proliferation and migration when overexpressed. However, BST2 knockdown rescued SP1 overexpression-induced PANC1 cell colony formation, proliferation and migration. In conclusion, activation of BST2 by the transcription factor SP1 was shown to accelerate pancreatic cancer cell proliferation and migration, suggesting that BST2 and SP1 may be plausible therapeutic targets in targeted therapy for pancreatic cancer.

MicroRNA miR-502-5p inhibits ovarian cancer genesis by downregulation of GINS complex subunit 2

Ovarian cancer (OC) is one of the most common malignancies with high incidence and mortality and the eighth most common cancer-associated mortality in women worldwide. Aberrant expression of the GINS complex subunit 2 (GINS2) gene and miR-502-5p has been associated with cancer progression. This study aims to investigate the specific molecular mechanism of the miR-502-5p-GINS2 axis in OC. GINS2 and miR-502-5p expression in OC tissues and cell lines was measured using RT-qPCR. Next, we investigated the interaction between miR-502-5p and GINS2 using a luciferase assay. The role of the miR-502-5p-GINS2 axis was detected by assessing cell proliferation, migration, and apoptosis levels, such as caspase-3 activity and caspase-3 protein expression, in the OC cell lines CaOV3 and SKOV3, respectively. MiR-502-5p expression was decreased, and GINS2 expression was dramatically elevated in OC tissues and cells. Upregulation of miR-502-5p expression repressed cellular proliferation and migration levels but increased the cellular apoptosis level. GINS2 overexpression enhanced the proliferation and migration levels but hampered OC cell apoptosis. Moreover, miR-502-5p inhibited GINS2 expression and suppressed OC tumorigenesis. miR-502-5p targeting GINS2 suppressed OC progression by inhibiting cell growth and promoting cell apoptosis. Hence, we provide a comprehensive understanding of OC involving both miR-502-5p and GINS2, which might be effective therapeutic targets for OC patients.

miR-133a-5p suppresses gastric cancer through TCF4 down-regulation

Background

The effect of microRNAs (miRNA) on cancer regulations has received a considerable amount of attention recently. MiR-133a-5p has been identified as an anti-tumor miRNA in several types of cancers. However, the effect of miR-133a-5p on gastric cancer (GC) have not been uncovered. In this study, we sought to evaluate the regulation of TCF4 expression by miR-133-5p and the role of the miR-25-3p/TCF4 axis in the progression of GC, with the aim of identifying a potential therapeutic target for GC.

Methods

TCGA (The Cancer Genome Atlas), GTEx (The Genotype-Tissue Expression) and GEO (Gene Expression Omnibus) database were used to analyze the expression and prognosis. We performed MTT and EdU assays to elucidate the effect on cell replication. Apoptotic cells were stained with annexin V-fluorescein isothiocyanate and propidium iodide to stain, and then analyzed by flow cytometry. The effect on cell metastasis was investigated in wound healing and transwell assays. A dual-luciferase reporter assay was used to check for the direct targeting of TCF4 by miR-133a-5p. Bioinformatic analysis of the relationship of TCF4 with tumor microenvironment and the signaling cascade of TCF4 was finally performed.

Results

We found that the level of miR-133a-5p was decreased in both tumor tissues and GC cell lines. MiR-133a-5p inhibited cell growth and metastasis, but promoted cell apoptosis. MiR-133a-5p directly targeted TCF4 and downregulated its expression. TCF4 was highly expressed in tumor and higher level of TCF4 indicated poorer prognosis. Moreover, TCF4 overexpression reversed the aforementioned anti-tumor activity of miR-133a-5p. The expression level of TCF4 was significantly correlated with tumor-infiltrating immune cells.

Conclusions

Our findings altogether reveal that miR-133a-5p can serve as a tumor suppressor in gastric cancer via the miR-133a-5p/TCF4 pathway.

Depletion of hsa_circ_0000144 Suppresses Oxaliplatin Resistance of Gastric Cancer Cells by Regulating miR-502-5p/ADAM9 Axis

Background

Circular RNAs (circRNAs) have been disclosed to exert important roles in human cancers, including gastric cancer (GC). CircRNA hsa_circ_0000144 was identified as an oncogene in GC development. The aim of our study was to explore the role of hsa_circ_0000144 in oxaliplatin (OXA) resistance of GC.

Methods

Expression levels of hsa_circ_0000144, microRNA-502-5p (miR-502-5p) and A disintegrin and metalloproteinase 9 (ADAM9) were examined by quantitative real-time PCR (RT-qPCR) or Western blot assay. The OXA resistance of GC cells was evaluated by Cell Counting Kit-8 (CCK-8) assay. Colony formation assay was performed to assess the colony formation capacity. Cell apoptosis was determined by flow cytometry and caspase 3 activity. And cell migration and invasion were detected by Transwell assay. Target association between miR-502-5p and hsa_circ_0000144 or ADAM9 was demonstrated by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Moreover, role of hsa_circ_0000144 in vivo was analyzed by xenograft tumor assay.

Results

Hsa_circ_0000144 and ADAM9 were highly expressed, while miR-502-5p was downregulated in OXA-resistant GC tissues and cells. Depletion of hsa_circ_0000144 could inhibit OXA resistance, proliferation and metastasis in OXA-resistant GC cells, which was attenuated by miR-502-5p inhibition. Hsa_circ_0000144 sponged miR-502-5p to positively regulate ADAM9 expression. MiR-502-5p suppressed OXA resistance, proliferation and metastasis in OXA-resistant GC cells by targeting ADAM9. Hsa_circ_0000144 knockdown could hamper tumor growth in vivo.

Conclusion

Hsa_circ_0000144 exerted inhibitory effects on OXA resistance, proliferation and metastasis of OXA-resistant GC cells by regulating miR-502-5p/ADAM9 axis, at least in part.