Transcriptional regulation of nuclear miRNAs in tumorigenesis (Review)

Clinical value of microRNA-4449 of non-small cell lung cancer patients undergoing thoracic paravertebral block thoracotomy

OBJECTIVE

The aim of this study was to investigate the clinical significance of microRNA-4449 (miR-4449) in patients attacked by non-small cell lung cancer (NSCLC) undergoing thoracic paravertebral block (TPVB) thoracotomy.

METHODS

A total of 122 patients diagnosed with NSCLC and 101 healthy individuals were recruited in this case-control study. Quantitative real-time polymerase reaction time (qRT-PCR) assay was applied to quantify the serum levels of miR-4449 in all participants. To assess the diagnostic potential of miR-4449, receiver operating characteristic (ROC) curves were constructed. Additionally, the prognostic value of miR-4449 was evaluated using Kaplan-Meier method and Cox regression analyses. The possible target genes and related proteins of miR-4449 were predicted via bioinformatics analysis.

RESULTS

MiR-4449 expression was notably reduced in NSCLC patients relative to healthy volunteers (P < 0.001), with the area under the curve (AUC) reaching 0.952, demonstrating its ability to effectively differentiate between NSCLC patients and healthy individuals. Serum levels of miR-4449 were negatively in relation to tumor node metastasis stage and lymph node metastasis (P < 0.05). Moreover, a significant increase in miR-4449 expression was observed in patients following TPVB thoracotomy, as compared to pre-operative levels (P < 0.001). The AUC of 0.884 further highlighted its potential to distinguish between the effective group and the invalid group. Notably, patients expressing high levels of miR-4449 exhibited improved overall survival (P < 0.001), and miR-4449 (P < 0.001, HR = 2.290, 95 % = 1.450-3.615) was identified as an independently prognostic predictor for NSCLC. Bioinformatics analysis of miR-4999 target genes revealed key tumor-associated pathways and proteins, offering valuable insights into its molecular mechanisms in NSCLC.

CONCLUSION

Serum levels of miR-4449 were significantly decreased in patients with NSCLC and exhibited a correlation with the severity of the tumor. Furthermore, miR-4449 emerged as a potential prognostic biomarker, offering valuable insight into the clinical outcome for NSCLC undergoing TPVB thoracotomy.

GABPα targeted by miR-378a-5p inhibits the growth and angiogenesis of colorectal carcinoma

Considering the high degree of malignancy, recurrence rate and poor prognosis, exploring promising targets is an imperious strategy for colorectal carcinoma therapy. Recent studies have indicated that GABPα plays a role in cancer aggressiveness, but its exact function and regulatory mechanisms in colorectal cancer progression remain unclear. This study aims to explore the biological role of GABPα and its upstream regulator, miR-378a-5p, in modulating cancer progression. The expression levels of GABPα and miR-378a-5p were analyzed through comprehensive data mining and qPCR assays. The functional effects of GABPα were assessed using CCK-8, wound healing, transwell invasion assay, tube formation and xenograft model in nude mice. A co-transfection assay was also performed to investigate the regulatory relationship between miR-378a-5p and GABPα. We found that GABPα expression was significantly downregulated in human colorectal cancer tissues and cell lines. Functional assays revealed that GABPα overexpression suppressed the proliferation, migration, invasion and angiogenesis of colorectal cancer cells, and in vivo experiments further confirmed the inhibitory role of GABPα. Additionally, miR-378a-5p was upregulated in colorectal cancer, and GABPα was identified as a direct target of miR-378a-5p, as confirmed by luciferase reporter assays. Furthermore, overexpression of GABPα partially counteracted the enhanced malignant behaviors of cancer cells induced by miR-378a-5p. Our findings suggest that miR-378a-5p promotes the aggressive progression of colorectal cancer by directly targeting GABPα, highlighting this regulatory axis as a potential therapeutic target for colorectal carcinoma.

Detection and simultaneous imaging of acrylamide, miR-21 and miR-221 based on multicolor aggregation-induced emission nanoparticles and DNAzyme walker

Acrylamide (AA) in heat-processed foods has emerged as a global health problem, mainly carcinogenic, neurotoxic, and reproductive toxicity, and an increasing number of researchers have delved into elucidating its toxicological mechanisms. Studies have demonstrated that exposure of HepG2 by AA in a range of concentrations can induce the upregulation of miR-21 and miR-221. Monitoring the response of intracellular miRNAs can play an important role in unraveling the mechanisms of AA toxicity. Here, multicolor aggregation induced emission nano particle (AIENP) probes were constructed from three AIE dyes for simultaneous imaging of intracellular AA and AA-induced miR-21/miR-221 by combining the recognition function of AA aptamers and the signal amplification of a DNAzyme walker. The surface of these nanoparticles contains carboxyl groups, facilitating their linkage to a substrate chain modified with a fluorescent quencher group via an amide reaction. Optimization experiments were conducted to determine the optimal substrate-to-DNAzyme ratio, confirming its efficacy as a walker for signal amplification. Sensitive detection of AA, miR-21 and miR-221 was achieved in extracellular medium, with detection limits of 0.112 nM for AA, 0.007 pM and 0.003 pM for miR-21 and miR-221, respectively, demonstrating excellent selectivity. Intracellularly, ZIF-8 structure collapsed, releasing Zn2+, activating DNAzyme cleavage activity, and the fluorescence of multicolor AIENPs within HepG2 cells gradually recovered with increasing stimulation time (0-12 h) and concentrations of AA (0-500 μM). This dynamic response unveiled the relationship between AA exposure and miR-21/miR-221 expression, further validating the carcinogenicity of AA.

miR-1-3p Inhibits Osteosarcoma Cell Proliferation and Cell Cycle Progression While Promoting Cell Apoptosis by Targeting CDK14 to Inactivate Wnt/Beta-Catenin Signaling

Osteosarcoma (OS) is a common bone malignancy and is diagnosed frequently in children and young adults. According to previous RNA sequencing, miR-1-3p is downregulated in OS clinical samples. Nevertheless, the functions of miR-1-3p in OS cell process and the related mechanism have not been revealed yet. In the current study, miR-1-3p expression in OS tissues and cells were evaluated using quantitative polymerase chain reaction. CCK-8 assays were conducted to measure OS cell viability in response to miR-1-3p overexpression. Colony forming assays and EdU staining were conducted for measurement of cell proliferation, and flow cytometry analysis was performed to determine cell apoptosis and cell cycle progression. Protein levels of apoptotic markers, beta-catenin, and Wnt downstream targets were quantified using western blotting. The binding relation between miR-1-3p and cyclin dependent kinase 14 (CDK14) was validated utilizing luciferase reporter assays. Experimental results revealed that miR-1-3p expression was decreased in OS tissues and cells. Additionally, miR-1-3p inhibited cell proliferation and cell cycle progression while enhancing OS cell apoptosis. Moreover, miR-1-3p directly targeted CDK14 and inversely regulated CDK14 expression in OS cells. Furthermore, miR-1-3p inactivated the Wnt/beta-catenin signaling. CDK14 overexpression partially rescued the inhibitory impact of miR-1-3p on OS cell growth. Overall, miR-1-3p inhibits OS cell proliferation and cell cycle progression while promoting cell apoptosis by targeting CDK14 and inactivating the Wnt/beta-catenin signaling.

RUNX1/miR-429 feedback loop promotes growth, metastasis, and epithelial-mesenchymal transition in oral squamous cell carcinoma by targeting ITGB1

This study aimed to explore the role of miR-429 on the progression of oral squamous cell carcinoma (OSCC). OSCC cell lines were transfected with miR-429 mimic, pcDNA3.1-RUNX1, or pcDNA3.1-ITGB1, and their cell viability, apoptosis, migration, and invasion abilities were analyzed by cell counting, terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, wound healing, and transwell assays, respectively. Furthermore, luciferase reporter assay, RNA pull-down, and ChIP were used to assess the regulation of miR-429, RUNX1, and ITGB1 expression in OSCC. Lastly, the biological role of the RUNX1/miR-429 feedback loop was explored in nude mice. The results revealed that miR-429 level was down-regulated, while RUNX1 and ITGB1 levels were up-regulated in OSCC tissues and that miR-429 was negatively correlated with RUNX1 and ITGB1 in OSCC tissues. Transfection of miR-429 mimic suppressed OSCC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). Moreover, we found that miR-429 participated in OSCC progression by directly targeting ITGB1. Additionally, we found that RUNX1 negatively regulated miR-429 expression by binding to its promoter. Our results also revealed that the RUNX1/miR-429 feedback loop regulated ITGB1 expression and that RUNX1 overexpression rescued the inhibitory effects of miR-429 mimic on OSCC cells. In addition, miR-429 mimic significantly suppressed tumor growth, inflammatory cell infiltration, EMT, and ITGB1 expression in vivo, which were inhibited by RUNX1 overexpression. Altogether, these results indicate that the RUNX1/miR-429 feedback loop promoted growth, metastasis, and EMT in OSCC by targeting ITGB1.

Nuclear miR-451a activates KDM7A and leads to cetuximab resistance in head and neck squamous cell carcinoma

Cetuximab resistance has been a major challenge for head and neck squamous cell carcinoma (HNSCC) patients receiving targeted therapy. However, the mechanism that causes cetuximab resistance, especially microRNA (miRNA) regulation, remains unclear. Growing evidence suggests that miRNAs may act as "nuclear activating miRNAs" for targeting promoter regions or enhancers related to target genes. This study elucidates a novel mechanism underlying cetuximab resistance in HNSCC involving the nuclear activation of KDM7A transcription via miR-451a. Herein, small RNA sequencing, quantitative real-time polymerase chain reaction (qRT‒PCR) and fluorescence in situ hybridization (FISH) results provided compelling evidence of miR-451a nuclear enrichment in response to cetuximab treatment. Chromatin isolation via RNA purification, microarray analysis, and bioinformatic analysis revealed that miR-451a interacts with an enhancer region in KDM7A, activating its expression and further facilitating cetuximab resistance. It has also been demonstrated that the activation of KDM7A by nuclear miR-451a is induced by cetuximab treatment and is AGO2 dependent. Logistic regression analyses of 87 HNSCC samples indicated the significance of miR-451a and KDM7A in the development of cetuximab resistance. These discoveries support the potential of miR-451a and KDM7A as valuable biomarkers for cetuximab resistance and emphasize the function of nuclear-activating miRNAs.

Study of miRNA and lymphocyte subsets as potential biomarkers for the diagnosis and prognosis of gastric cancer

Objective

The aim of this study was to identify the expression of miRNA and lymphocyte subsets in the blood of gastric cancer (GC) patients, elucidate their clinical significance in GC, and establish novel biomarkers for the early diagnosis and prognosis of GC.

Methods

The expression of miRNAs in the serum of GC patients was screened using second-generation sequencing and detected using qRT-PCR. The correlation between miRNA expression and clinicopathological characteristics of GC patients was analyzed, and molecular markers for predicting cancer were identified. Additionally, flow cytometry was used to detect the proportion of lymphocyte subsets in GC patients compared to healthy individuals. The correlations between differential lymphocyte subsets, clinicopathological features of GC patients, and their prognosis were analyzed statistically.

Results

The study revealed that hsa-miR-1306-5p, hsa-miR-3173-5p, and hsa-miR-296-5p were expressed at lower levels in the blood of GC patients, which is consistent with miRNA-seq findings. The AUC values of hsa-miR-1306-5p, hsa-miR-3173-5p, and hsa-miR-296-5p were found to be effective predictors of GC occurrence. Additionally, hsa-miR-296-5p was found to be negatively correlated with CA724. Furthermore, hsa-miR-1306-5p, hsa-miR-3173-5p, and hsa-miR-296-5p were found to be associated with the stage of the disease and were closely linked to the clinical pathology of GC. The lower the levels of these miRNAs, the greater the clinical stage of the tumor and the worse the prognosis of gastric cancer patients. Finally, the study found that patients with GC had lower absolute numbers of CD3+ T cells, CD4+ T cells, CD8+ T cells, CD19+ B cells, and lymphocytes compared to healthy individuals. The quantity of CD4+ T lymphocytes and the level of the tumor marker CEA were shown to be negatively correlated. The ROC curve and multivariate logistic regression analysis demonstrated that lymphocyte subsets can effectively predict gastric carcinogenesis and prognosis.

Conclusion

These miRNAs such as hsa-miR-1306-5p, hsa-miR-3173-5p, hsa-miR-296-5p and lymphocyte subsets such as the absolute numbers of CD3+ T cells, CD4+ T cells, CD8+ T cells, CD19+ B cells, lymphocytes are down-regulated in GC and are closely related to the clinicopathological characteristics and prognosis of GC patients. They may serve as new molecular markers for predicting the early diagnosis and prognosis of GC patients.

MicroRNA-15a/β1,4-GalT-I axis contributes to cartilage degeneration via NF-κB signaling in osteoarthritis

OBJECTIVE

Osteoarthritis is a condition characterized by articular cartilage degradation. The increased expression of β1,4-Galactosyltransferase-I (β1,4-GalT-I) in the articular cartilage of osteoarthritis patients was related to an inflammatory response. The aim of this study was to elucidate the role of β1,4-GalT-I in osteoarthritis. This study aimed to determine the function of 1,4-GalT-I in osteoarthritis.

METHODS

The osteoarthritis mouse model with the destabilization of the medial meniscus was established by microsurgical technique. Pathological changes in articular cartilage were observed by hematoxylin and eosin staining and safranin O-fast green staining. Quantitative real-time polymerase chain reaction, western blot, and enzyme-linked immunosorbent assays were used to observe mRNA and protein expression, respectively. RNA interactions were verified by a luciferase reporter assay. SA-β-Gal staining was used to assess chondrocyte senescence. Immunofluorescence staining was conducted to observe the localization of Nuclear Factor-kappaB (NF-κB).

RESULTS

β1,4-GalT-I and microRNA-15a (miR-15a) show high and low expression in the articular cartilage of osteoarthritis, respectively. MiR-15a inhibits the mRNA translation of β1,4-GalT-I. β1,4-GalT-I promotes extracellular matrix degradation, senescence, and NF-κB activation in IL-1β-stimulated chondrocytes, which can be reversed by overexpression of miR-15a. Intra-articular injection of microRNA-15a ameliorates cartilage degeneration by inhibiting β1,4-GalT-I and phosphorylation of NF-κB in vivo.

CONCLUSION

The authors clarified that the miR-15a/β1,4-GalT-I axis inhibits the phosphorylation of NF-κB thereby inhibiting extracellular matrix degradation and senescence in chondrocytes to alleviate cartilage degeneration in osteoarthritis. MiR-15a and β1,4-GalT-I may serve as potentially effective targets for the future treatment of osteoarthritis.

MicroRNA-146a-5p induces cell cycle arrest and enhances apoptosis in gastric cancer via targeting CDC14A

Objective: The present study was designed to investigate the expression of miRNA-146a-5p in gastric cancer (GC) tissues and the paired nonmalignant counterparts, to explore the influences of miRNA-146a-5p on the cell biological behavior of MKN-28 cells (highly metastatic human gastric cancer cells), and to identify the function of abnormal expression of its target gene cell division cycle 14 homolog A (CDC14A) in GC. Methods: We detected the expression of miRNA-146a-5p in formalin-fixed and paraffin-embedded (FFPE) GC tissues through microarray and quantitative real-time polymerase chain reaction (qRT-PCR). Then, we employed cell counting kit-8 (CCK-8) assays, cell cycle assays, and apoptosis analysis to uncover the latent function of miRNA-146a-5p in MKN-28 human GC cells. We also validated the target of miRNA-146a-5p via luciferase reporter assays. Results: miRNA-146a-5p levels were examined in the majority of primary GC tissues and several GC cell lines. As a result, miRNA-146a-5p levels were significantly declined in the GC tissues and cells. In addition, miRNA-146a-5p demonstrated a straight act on its 3'-untranslated region (3'-UTR) of CDC14A mRNA, accordingly decreasing the contents of CDC14A mRNA as well as its protein expression. An inverse correlation between CDC14A and miRNA-146a-5p was observed. Conclusion: The data suggest miRNA-146a-5p may contribute to inducing cell cycle arrest as well as prompting GC cell apoptosis via directly targeting CDC14A. Therefore, miRNA-146a-5p may be a potential indicator of the occurrence and development of GC.

The Expression of miR-34c-5p Induces G0/G1 Cell Cycle Arrest and Apoptosis in SW480 Colon Cancer Cell

Background

Expression of the miR-34 family, including miR-34a/b/c, has been reported to inhibit the progression of several cancer types by inhibiting cell proliferation and inducing apoptosis.

Objectives

We attempted to investigate the effect of SW480 cell transfection with miR-34c-5p mimics on cell proliferation.

Methods

To do this, SW480 colon cancer cell line was transfected with miR-34c-5p mimics, scramble sequence, and the vehicle in PBS mock, and then cell proliferation was assessed by MTT assay. The population of cells in cell cycle phases, ROS generation, and apoptosis rate were evaluated by flow cytometry. Additionally, we determined the relative expression of apoptotic genes through real-time PCR technique.

Results

We observed a reduced proliferation rate in cells transfected with miR-34c-5p compared to the control group (P <0.05). We also found that miR-34c-5p caused a significant increase in apoptosis rate (P < 0.001) and cell cycle arrest in the G0 and G1 phases (P < 0.05). Moreover, a significant increase was reported in the expression of pro-apoptotic genes, including BAK (P < 0.001), BAX and BAD (P < 0.0001), and Caspase 7/9 (P < 0.0001).

Conclusions

However, no remarkable difference was seen in the expression of MCL1, BCL2, and CASPASE 3 genes. Our conclusion is that overexpression of miR-34c-5p could be considered a promising approach for colorectal cancer treatment.