Effects of miR-135a-5p and miR-141 on proliferation, invasion and apoptosis of colorectal cancer SW620 cells

Circulating cell-free and extracellular vesicles-derived microRNA as prognostic biomarkers in patients with early-stage NSCLC: results from RESTING study

BACKGROUND

Factors to accurately stratify patients with early-stage non-small cell lung cancer (NSCLC) in different prognostic groups are still needed. This study aims to investigate 1) the prognostic potential of circulating cell-free (CF) and extracellular vesicles (EVs)-derived microRNA (miRNAs), and 2) their added value with respect to known prognostic factors (PFs).

METHODS

The RESTING study is a multicentre prospective observational cohort study on resected stage IA-IIIA patients with NSCLC. The primary end-point was disease-free survival (DFS), and the main analyses were carried out separately for CF- and EV-miRNAs. CF- and EV-miRNAs were isolated from plasma, and miRNA-specific libraries were prepared and sequenced. To reach the study aims, three statistical models were specified: one using the miRNA data only (Model 1); one using both miRNAs and known PFs (age, gender, and pathological stage) (Model 2), and one using the PFs alone (Model 3). Five-fold cross-validation (CV) was used to assess the predictive performance of each. Standard Cox regression and elastic net regularized Cox regression were used.

RESULTS

A total of 222 patients were enrolled. The median follow-up time was 26.3 (95% CI 25.4-27.6) months. From Model 1, three CF-miRNAs and 21 EV-miRNAs were associated with DFS. In Model 2, two CF-miRNAs (miR-29c-3p and miR-877-3p) and five EV-miRNAs (miR-181a-2-3p, miR-182-5p, miR-192-5p, miR-532-3p and miR-589-5p) remained associated with DFS. From pathway enrichment analysis, TGF-beta and NOTCH were the most involved pathways.

CONCLUSION

This study identified promising prognostic CF- and EV-miRNAs that could be used as a non-invasive, cost-effective tool to aid clinical decision-making. However, further evaluation of the obtained miRNAs in an external cohort of patients is warranted.

Role of non-coding RNAs as new therapeutic targets in regulating the EMT and apoptosis in metastatic gastric and colorectal cancers

Colorectal cancer (CRC) and gastric cancer (GC), are the two most common cancers of the gastrointestinal tract, and are serious health concerns worldwide. The discovery of more effective biomarkers for early diagnosis, and improved patient prognosis is important. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), can regulate cellular processes such as apoptosis and the epithelial-mesenchymal transition (EMT) leading to progression and resistance of GC and CRC tumors. Moreover these pathways (apoptosis and EMT) may serve as therapeutic targets, to prevent metastasis, and to overcome drug resistance. A subgroup of ncRNAs is common to both GC and CRC tumors, suggesting that they might be used as biomarkers or therapeutic targets. In this review, we highlight some ncRNAs that can regulate EMT and apoptosis as two opposite mechanisms in cancer progression and metastasis in GC and CRC. A better understanding of the biological role of ncRNAs could open up new avenues for the development of personalized treatment plans for GC and CRC patients.

MiR-135a-5p suppresses breast cancer cell proliferation, migration, and invasion by regulating BAG3

BACKGROUND

MicroRNAs (miRNAs) are involved in the progression of diverse human cancers. This work aimed to delve into how microRNA-135a-5p (miR-135a-5p) affects the biological behaviors of Breast Cancer (BC) cells.

METHODS

Gene Expression Omnibus (GEO) datasets were used to analyze the expression differences of miR-135a-5p in cancer tissues of BC patients. Quantitative real-time PCR and western blot were conducted to detect miR-135a-5p and Bcl-2 Associated Athanogene (BAG3) expression levels in BC tissues and cells, respectively. The proliferation, migration, invasion, and cell cycle of BC cells were detected by cell counting kit-8 assay, BrdU assay, wound healing assay, transwell assay, and flow cytometry. The targeted relationship between miR-135a-5p and BAG3 mRNA 3'UTR predicted by bioinformatics was further testified by a dual-luciferase reporter gene assay. Pearson's correlation analysis was adopted to analyze the correlation between miR-135a-5p expression and BAG3 expression. The downstream pathways of BAG3 were analyzed by the LinkedOmics database.

RESULTS

MiR-135a-5p was significantly down-regulated and BAG3 expression was significantly raised in BC tissues. MiR-135a-5p overexpression repressed the viability, migration and invasion of BC cells, and blocked cell cycle progression in G0/G1 phase while inhibiting miR-135a-5p worked oppositely. BAG3 was verified as a target of miR-135a-5p. Overexpression of BAG3 reversed the impacts of miR-135a-5p on the malignant biological behaviors of BC cells. The high expression of BAG3 was associated with the activation of the cell cycle, mTOR and TGF-β signaling pathways.

CONCLUSION

MiR-135a-5p regulates BAG3 to repress the growth, migration, invasion, and cell cycle progression of BC cells.

The Role and Interactions of Programmed Cell Death 4 and its Regulation by microRNA in Transformed Cells of the Gastrointestinal Tract

Data from GLOBOCAN 2020 estimates that there were 19.3 million new cases of cancer and 10.0 million cancer-related deaths in 2020 and that this is predicted to increase by 47% in 2040. The combined burden of cancers of the gastrointestinal (GI) tract, including oesophageal-, gastric- and colorectal cancers, resulted in 22.6% of the cancer-related deaths in 2020 and 18.7% of new diagnosed cases. Understanding the aetiology of GI tract cancers should have a major impact on future therapies and lessen this substantial burden of disease. Many cancers of the GI tract have suppression of the tumour suppressor Programmed Cell Death 4 (PDCD4) and this has been linked to the expression of microRNAs which bind to the untranslated region of PDCD4 mRNA and either inhibit translation or target the mRNA for degradation. This review highlights the properties of PDCD4 and documents the evidence for the regulation of PDCD4 expression by microRNAs in cancers of the GI tract.

Regulation of Gamma-Aminobutyric Acid Transaminase Expression and Its Clinical Significance in Hepatocellular Carcinoma

Background

Gamma-aminobutyric acid transaminase (ABAT) catalyzes the conversion of gamma-aminobutyric acid (GABA) into succinic semialdehyde. Although some evidence supports a key role of ABAT in the progression of hepatocellular carcinoma (HCC), no systematic analysis is available. Thus, this study aimed to investigate the possible mechanisms related to low ABAT expression and the prognostic value and potential functions of ABAT in HCC.

Methods

We obtained relevant datasets from the Encyclopedia of RNA Interactomes, MethSurv, cBioPortal, TISIDB and The Cancer Genome Atlas and used bioinformatic methods to analyze DNA methylation, copy number variation, gene mutation, and upstream microRNAs (miRNAs) of ABAT, exploring the potential relationship between ABAT expression and the prognosis, glycolysis, and immune infiltration in HCC.

Results

The results indicated that ABAT expression was lower in HCC tumor tissues than in normal tissues or adjacent tissues. Low ABAT expression was related to patient age, T stage classification, pathologic stage, histological grade, and alpha-fetoprotein level of HCC. Kaplan-Meier survival analyses indicated that low ABAT expression was correlated with poor HCC prognosis. ABAT was also verified as an independent risk factor in HCC via Cox multivariate analysis. Gene set enrichment analysis showed enrichment in various signaling pathways. Furthermore, DNA methylation, copy number variation, and gene mutation potentially induced low ABAT expression; miR-135a-5p was a potential upstream miRNA of ABAT. Additionally, ABAT expression was associated with glycolysis-related genes, infiltrated immune cells, immunoinhibitors, and immunostimulators in HCC.

Conclusions

Our study reveals that deficient ABAT expression is correlated with disease progression and poor prognosis in HCC because of its role in tumorigenesis and tumor immunity.

lncRNA FOXD3-AS1 promotes the progression of non-small cell lung cancer by regulating the miR-135a-5p/CDK6 axis

Long non-coding RNA (lncRNA) is essential to the development and progression of malignant human cancer. Growing evidence suggests that the lncRNA forkhead box D3 antisense 1 (FOXD3-AS1) is a crucial regulatory effector for multiple cancer types and is closely associated with poor prognosis. However, in most cases, the molecular mechanism underlying the role of FOXD3-AS1 in cancer development has not yet been fully elucidated. The present study focused on non-small cell lung cancer (NSCLC) in order to gain insight into how FOXD3-AS1 drives cancer progression. First, FOXD3-AS1 expression in NSCLC tissue samples was detected using reverse transcription-quantitative (RT-qPCR). Moreover, cell proliferation and apoptosis were determined using Cell Counting Kit-8 assays and flow cytometry, respectively. A luciferase reporter assay was then performed to determine whether there was a direct binding association between FOXD3-AS1 and microRNA (miR)-135a-5p. Lastly, a tumor subcutaneous xenograft model was established to examine the role of FOXD3-AS1 in tumor growth. FOXD3-AS1 was significantly overexpressed in NSCLC tissue samples and cell lines compared with normal tissue samples and cells. FOXD3-AS1 silencing expression significantly inhibited A549 and H1229 cell proliferation while inducing apoptosis compared with sh-NC group. The luciferase reporter assay demonstrated the direct binding interaction between FOXD3-AS1 and miR-135a-5p. Moreover, FOXD3-AS1 silencing led to the upregulation of miR-135a-5p in A549 and H1229 cells compared with sh-NC group. It was also demonstrated that miR-135a-5p could bind to the 3′ untranslated region of cyclin-dependent kinase 6 (CDK6) and negatively modulate its transcription. miR-135a-5p knockdown or CDK6 overexpression reversed the inhibition on cell proliferation and apoptosis following FOXD3-AS1 knockdown. Altogether, the present study suggests that FOXD3-AS1 sponges miR-135a-5p to promote cell proliferation and concomitantly inhibit apoptosis by regulating CDK6 expression in NSCLC cells.

Bortezomib Inhibits Multiple Myeloma Cells by Transactivating ATF3 to Trigger miR-135a-5p- Dependent Apoptosis

Multiple myeloma (MM) is a malignant cancer with an increasing in incidence that can be alleviated through bortezomib (BTZ) treatment. Activating transcription factor 3 (ATF3) plays a major role in cancer development. Moreover, microRNAs (miRNAs) regulate carcinogenic pathways, apoptosis, and programmed necrotic cell death. However, the detailed mechanism by which ATF3 modulates BTZ drug sensitivity/resistance remains elusive. In the current study, expression of ATF3 was significantly increased under BTZ treatment in a dose-dependent manner in MM cell lines. In addition, ATF3 could regulate cell apoptosis under BTZ treatment. The effect of ATF3 was negatively regulated by its binding miRNA, miR-135a-5p. When either ATF3 was silenced or miR-135a-5p mimics were added to MM cells, they partially lost sensitivity to BTZ treatment. This was accompanied by low levels of Noxa, CHOP, and DR5, and a decrease in mitochondrial membrane potential. These results revealed the combinatorial regulatory patterns of ATF3 and miR-135a-5p in the regulatory protein interactome, which indicated a clinical significance of the miR-135a-5p-ATF3 protein interaction network in BTZ therapy. This study provides potential evidence for further investigation into BTZ resistance.

MicroRNA-135a expression is upregulated in hepatocellular carcinoma and targets long non-coding RNA TONSL-AS1 to suppress cell proliferation

Dysregulation of long non-coding RNAs (lncRNAs) results in development of human diseases, including hepatocellular carcinoma (HCC). lncRNA TONSL-AS1 has been reported to act as a tumor suppressor in gastric cancer. The present study aimed to investigate the role of TONSL-AS1 in hepatocellular carcinoma (HCC). Reverse transcription-quantitative PCR analysis was performed to detect the expression levels of TONSL-AS1 and microRNA (miRNA/miR)-135a in HCC tissues and paired adjacent normal tissues. A 5-year follow-up study was performed to determine the prognostic value of TONSL-AS1 in HCC. The association between miR-135a and TONSL-AS1 was assessed via overexpression experiments. The Cell Counting Kit-8 assay was performed to assess cell proliferation. The results demonstrated that TONSL-AS1 expression was downregulated in HCC tissues, which was associated with a lower survival rate in patients with HCC. TONSL-AS1 and miR-135a were predicted to interact with each other, whereby overexpression of miR-135a downregulated TONSL-AS1 expression. The results demonstrated that TONSL-AS1 and miR-135a were inversely correlated with each other. Notably, overexpression of TONSL-AS1 inhibited HCC cell proliferation, while overexpression of miR-135a promoted HCC cell proliferation and decreased the effect of overexpression of TONSL-AS1 on cell proliferation. Taken together, the results of the present study suggest that miR-135a expression is upregulated in HCC and targets lncRNA TONSL-AS1 to suppress cell proliferation.