microRNA-301b-3p downregulation underlies a novel inhibitory role of long non-coding RNA MBNL1-AS1 in non-small cell lung cancer

MicroRNAs: circulating biomarkers for the early detection of imperceptible cancers via biosensor and machine-learning advances

This review explores the topic of microRNAs (miRNAs) for improved early detection of imperceptible cancers, with potential to advance precision medicine and improve patient outcomes. Historical research exploring miRNA's role in cancer detection collectively revealed initial hurdles in identifying specific miRNA signatures for early-stage and difficult-to-detect cancers. Early studies faced challenges in establishing robust biomarker panels and overcoming the heterogeneity of cancer types. Despite this, recent developments have supported the potential of miRNAs as sensitive and specific biomarkers for early cancer detection as well as having demonstrated remarkable potential as diagnostic tools for imperceptible cancers, such as those with elusive symptoms or challenging diagnostic criteria. This review discusses the advent of high-throughput technologies that have enabled comprehensive detection and profiling of unique miRNA signatures associated with early-stage cancers. Furthermore, advancements in bioinformatics and machine-learning techniques are considered, exploring the integration of multi-omics data which have potential to enhance both the accuracy and reliability of miRNA-based cancer detection assays. Finally, perspectives on the continuing development on technologies as well as discussion around challenges that remain, such as the need for standardised protocols and addressing the complex interplay of miRNAs in cancer biology are conferred.

Role of miR-301b-3p/5p in breast cancer: A study based on the cancer GenomeAtlas program (TCGA) and bioinformatics analysis

Background

Breast cancer is one of the most common cancer type of women in the world. miR-301b-3p/5p were paired miRNAs derived from the same pre-miRNA, which may have different clinical roles in tumor and requires more exploration and research.

Methods

In order to investigate the differential expression, clinical significance, diagnostic and prognostic value of miR-301b-3p/5p and explore their function in breast cancer, we extracted information of miRNAs from TCGA data sets for clinical correlation analysis, and the potential function was explored by GO、KEGG enrichment and immunoinfiltration analysis.

Results

miR-301b-3p/5p were both highly expressed in breast cancer, there is a positive correlation between them. miR-301b-3p and miR-301b-5p have different clinical features. In breast cancer, miR-301b-3p can be used as a potential diagnostic marker while miR-301b-5p can be used as a prognostic molecule. GO, KEGG enrichment and immunoinfiltration analysis reveals that miR-301b-3p focuses on molecular functions, miR-301b-5p focuses on regulation of angiogenesis, and it is correlated with immune cells.

Conclusions

miR-301b-3p and miR-301b-5p are both tumor promoter in breast cancer, miR-301b-3p can be used as a potential diagnostic marker, while miR-301b-5p can be used as a prognostic molecule and an underlying therapy target. Although miR-301b-3p/5p is a pair of miRNAs from two arms of the same pre-miRNA, they may promote the progression of breast cancer together through different pathway.

microRNA-301b-3p from mesenchymal stem cells-derived extracellular vesicles inhibits TXNIP to promote multidrug resistance of gastric cancer cells

OBJECTIVE

MicroRNAs (miRNAs) from mesenchymal stem cells (MSC)-derived extracellular vesicles (MSCs-EVs), including exosomes, are known to participate in different diseases. However, the function of miR-301b-3p from MSCs-EVs on the chemoresistance of gastric cancer (GC) cells remains poorly characterized. Thus, we aim to explore the role of MSCs-EVs-derived miR-301b-3p in multidrug resistance of GC cells.

METHODS

Cisplatin (DDP)/vincristine (VCR)-resistant and sensitive GC clinical samples were harvested to detect expression of miR-301b-3p and thioredoxin interacting protein (TXNIP). MSCs were respectively transfected with miR-301b-3p oligonucleotides and/or TXNIP plasmids to extract the EVs, which were then co-cultured with multidrug-resistant GC cells. Then, P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP), IC50, proliferation, migration, and apoptosis of resistant GC cells were determined. The tumor growth was observed in nude mice. Targeting relationship between miR-301b-3p and TXNIP was confirmed.

RESULTS

miR-301b-3p was upregulated, and TXNIP was downregulated in DDP/VCR-resistant GC tissues and cells. MSC-EVs induced drug resistance, proliferation, and migration and inhibited apoptosis of DDP/VCR-resistant GC cells in vitro, as well as facilitated tumor growth in vivo. Inhibition of miR-301b-3p or upregulation of TXNIP reversed the promoting effect of MSC-EVs on DDP/VCR resistant GC cells to DDP/VCR resistance and malignant behaviors. The effects of MSC-EVs carrying miR-301b-3p inhibition on DDP/VCR-resistant GC cells were reversed by TXNIP downregulation. TXNIP was confirmed as a target gene of miR-301b-3p.

CONCLUSION

miR-301b-3p from MSCs-EVs inhibits TXNIP to promote multidrug resistance of GC cells, providing a novel insight for chemotherapy in GC.

The Importance of the Immune System and Molecular Cell Signaling Pathways in the Pathogenesis and Progression of Lung Cancer

Lung cancer is a disease that in recent years has become one of the greatest threats to modern society. Every year there are more and more new cases and the percentage of deaths caused by this type of cancer increases. Despite many studies, scientists are still looking for answers regarding the mechanisms of lung cancer development and progression, with particular emphasis on the role of the immune system. The aim of this literature review was to present the importance of disorders of the immune system and the accompanying changes at the level of cell signaling in the pathogenesis of lung cancer. The collected results showed that in the process of immunopathogenesis of almost all subtypes of lung cancer, changes in the tumor microenvironment, deregulation of immune checkpoints and abnormalities in cell signaling pathways are involved, which contribute to the multistage and multifaceted carcinogenesis of this type of cancer. We, therefore, suggest that in future studies, researchers should focus on a detailed analysis of tumor microenvironmental immune checkpoints, and to validate their validity, perform genetic polymorphism analyses in a wide range of patients and healthy individuals to determine the genetic susceptibility to lung cancer development. In addition, further research related to the analysis of the tumor microenvironment; immune system disorders, with a particular emphasis on immunological checkpoints and genetic differences may contribute to the development of new personalized therapies that improve the prognosis of patients.

LncRNA MBNL1-AS1 Suppresses Cell Proliferation and Metastasis of Pancreatic Adenocarcinoma through Targeting Carcinogenic miR-301b-3p

Pancreatic adenocarcinoma (PAAD) has been a huge challenge to public health due to its increasing incidence, frequent early metastasis, and poor outcome. The molecular basis of tumorigenesis and metastasis in PAAD is largely unclear. Here, we identified a novel tumor-suppressor long noncoding RNA (lncRNA) MBNL1-AS1, in PAAD and revealed its downstream mechanism. Quantitative real-time PCR (qRT-PCR) data showed that MBNL1-AS1 expression was significantly downregulated in PAAD tissues and cells, which was closely associated with metastasis and poor prognosis. Cell counting kit-8 (CCK-8) assay, transwell assay, and western blot verified that overexpression of MBNL1-AS1 suppressed cell proliferation, migration, and epithelial mesenchymal transformation (EMT) behavior in PAAD cells. By using a dual luciferase reporter gene system, we confirmed that miR-301b-3p was a direct target of MBNL1-AS1. Further mechanismic study revealed that upregulation of miR-301b-3p abolished the inhibitory effect of MBNL1-AS1 overexpression on cell proliferation, tumorigenesis, migration and EMT. Our results demonstrate that MBNL1-AS1 plays a tumor-suppressive role in PAAD mainly by downregulating miR-301b-3p, providing a novel therapeutic target for PAAD.

LINC01089, suppressed by YY1, inhibits lung cancer progression by targeting miR-301b-3p/HPDG axis

PURPOSE

LINC01089 is a newly identified lncRNA and rarely reported in human cancers. Our study aimed to investigate its role in lung cancer.

METHODS

YY1, LINC01089, and miR-301b-3p levels in lung cancer tissues and cells were assessed using qRT-PCR. Bioinformatics analysis and luciferase reporter, ChIP, and RIP assays were carried out for determining the relationships among YY1, LINC01089, miR-301b-3p, and HPGD. Gain- and loss-of-function assays were carried out to confirm the impacts of LINC01089 and HPDG in lung cancer cells. CCK-8 assay was used to assess cell proliferation rate, and Transwell assay was applied to measure cell invasion and migration. An in vivo tumor model was applied for validating the role of LINC01089.

RESULTS

LINC01089 was decreased in lung cancer tissues and cells, and low LINC01089 level predicted a poor clinical outcome. YY1 directly bound to LINC01089 promoter region and inhibited its transcription. LINC01089 knockdown thwarted the proliferation, invasion, and migration capacity of H1299 and A549 cells and aggravated tumor growth. Specifically, LINC01089 functioned as a competing endogenous RNA of miR-301b-3p to modulate HPGD and thereby affected lung cancer progression.

CONCLUSION

Our data revealed that LINC01089, directly suppressed by YY1, inhibited lung cancer progression by targeting the miR-301b-3p/HPGD axis. Graphical abstract 1. LINC01089 expression was downregulated in lung cancer tisuues and cell lines, and low LINC01089 levels predicted a poor clinical outcome. 2. LINC01089 knockdown enhanced proliferation, invasion, and migration of H1299 and A549 cells in vitro and promoted lung cancer cell tumorigenesis and metastasis in vivo. 3. LINC01089, directly suppressed by YY1, functioned as a competing endogenous RNA against miR-301b-3p to increase HPGD expression.

Down-Regulation of lncRNA MBNL1-AS1 Promotes Tumor Stem Cell-like Characteristics and Prostate Cancer Progression through miR-221-3p/CDKN1B/C-myc Axis

The recurrence, progression, and drug resistance of prostate cancer (PC) is closely related to the cancer stem cells (CSCs). Therefore, it is necessary to find the key regulators of prostate cancer stem cells (PCSCs). Here, we analyzed the results of a single-class logistic regression machine learning algorithm (OCLR) to identify the PCSC-associated lncRNA MBNL1-AS1. The effects of MBNL1-AS1 on the stemness of CSCs was assessed using qPCR, western blot and sphere-forming assays. The role of MBNL1-AS1 in mediating the proliferation and invasion of the PC cell lines was examined using Transwell, wounding-healing, CCK-8, EdU and animal assays. Dual-luciferase and ChIRP assays were used to examine the molecular mechanism of MBNL1-AS1 in PCSCs. MBNL1-AS1 was shown to be negatively correlated with stemness index (mRNAsi), and even prognosis, tumor progression, recurrence, and drug resistance in PC patients. The knockdown of MBNL1-AS1 significantly affected the stemness of the PC cells, and subsequently their invasive and proliferative abilities. Molecular mechanism studies suggested that MBNL1-AS1 regulates CDKN1B through competitive binding to miR-221-3p, which led to the inhibition of the Wnt signaling pathway to affect PCSCs. In conclusion, our study identified MBNL1-AS1 as a key regulator of PCSCs and examined its mechanism of action in the malignant progression of PC.

Recent insights into the microRNA and long non-coding RNA-mediated regulation of stem cell populations

Stem cells are undifferentiated cells that have multi-lineage differentiation. The transition from self-renewal to differentiation requires rapid and extensive gene expression alterations. Since different stem cells exhibit diverse non-coding RNAs (ncRNAs) expression profiles, the critical roles of ncRNAs in stem cell reprogramming, pluripotency maintenance, and differentiation have been widely investigated over the past few years. Hence, in this current review, the two main categories of ncRNAs, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are discussed. While the primary way by which miRNAs restrict mRNA transcription is through miRNA-mRNA interaction, lncRNAs have a wide range of effects on mRNA functioning, including interactions with miRNAs. Both of these ncRNAs participate in the post-transcriptional regulation of crucial biological mechanisms, such as cell cycle regulation, apoptosis, aging, and cell fate decisions. These findings shed light on a previously unknown aspect of gene regulation in stem cell fate determination and behavior. Overall, we summarized the key roles of miRNAs (including exosomal miRNAs) and lncRNAs in the regulation of stem cell populations, such as cardiac, hematopoietic, mesenchymal, neural, and spermatogonial, as well ncRNAs' influence on malignancy through modulating cancer stem cells, which might significantly contribute to clinical stem cell therapy and in regenerative medicine.

LncRNA MBNL1-AS1 Represses Proliferation and Cancer Stem-Like Properties of Breast Cancer through MBNL1-AS1/ZFP36/CENPA Axis

Background

Emerging studies have revealed long noncoding RNAs (lncRNAs) were key regulators of cancer progression. In this research, the expression and roles of MBNL1-AS1 were explored in breast cancer (BC).

Methods

In this study, the MBNL1-AS1 expression in breast cancer tissue, as well as in cell line, was studied by qRT-PCR assays. The effects of MBNL1-AS1 on proliferation and stemness were evaluated by MTT assays, colony formation assays, orthotopic breast tumor mice models, extreme limiting dilution analysis (ELDA), fluorescence in situ hybridization (FISH), flow cytometry assays, and sphere formation assays. Flexmap 3D assays were performed to show that MBNL1-AS1 downregulated the centromere protein A (CENPA) secretion in BC cells. Western blot, RNA pull-down assays, RNA immunoprecipitation (RIP) assays, and FISH were conducted to detect the mechanism.

Results

The results showed that the expression levels of MBNL1-AS1 were downregulated in breast cancer tissues and cell lines. In vitro and in vivo studies demonstrated that overexpression of MBNL1-AS1 markedly inhibited BC cells proliferation and stemness. RNA pull-down assay, RIP assay, western blot assay, and qRT-PCR assay showed that MBNL1-AS1 downregulated CENPA mRNA via directly interacting with Zinc Finger Protein 36 (ZFP36) and subsequently decreased the stability of CENPA mRNA. Restoration assays also confirmed that MBNL1-AS1 suppressed the CENPA-mediated proliferation and stemness in breast cancer cells.

Conclusions

The new mechanism of how MBNL1-AS1 regulates BC phenotype is elucidated, and the MBNL1-AS1/ZFP36/CENPA axis may be served as a therapeutic target for BC patients.

Analysis of Genetic Variants and the ceRNA Network of miR-9 in Non-Small Cell Lung Cancer

Objective: To explore the role of single-nucleotide polymorphisms (SNPs) in hsa-miR-9 in non-small cell lung cancer (NSCLC). Methods: Log-rank and Cox regression analyses were conducted to assess the association of four functional SNPs of miR-9 with overall survival (OS) of Chinese patients with NSCLC. A reporter luciferase assay was performed to examine the relationship between the SNPs and transcriptional activity of miR-9. The expression of miR-9 in cells was detected by quantitative real-time PCR assay. Xenograft model was established in nude mice, which were treated with Lv-MiR-9-mimics or Lv-miR-9-inhibitor. A long noncoding RNA (lncRNA)-miR-9-messenger RNA (mRNA) competing endogenous RNA (ceRNA) network was established based on bioinformatics analyses. Results: We found that rs1501672 was associated with the prognosis of 1001 Chinese NSCLC patients (A>G, additive model: adjusted hazard ratio = 0.89, 95% confidence interval = 0.79-1.00, p = 0.056). Luciferase reporter assay showed higher luciferase activity with wild A allele than that with mutant G allele in 293T, SPC-A1, and A549 cell lines. The miR-9 level was significantly higher in lung cancer cells than normal lung cells. miR-9 was also over expressed in lung cancer tissue according to The Cancer Genome Atlas and gene expression omnibus databases. Xenograft models based on H1299 cells showed that lv-miR-9-inhibitor significantly decreased tumor growth compared with the lv-miR-9-NC group (p < 0.001). Bioinformatics analysis showed that one target gene leukemia inhibitory factor receptor and two lncRNAs (KIAA0087 and GVINP1) were associated with OS of NSCLC patients. Conclusion: The rs1501672 of miR-9 was associated with the prognosis of NSCLC patients in the Chinese population. The lncRNA-miR-9-mRNA ceRNA network revealed potential molecular biological regulation pathways and prognostic biomarkers for NSCLC.

A novel circ_MACF1/miR-942-5p/TGFBR2 axis regulates the functional behaviors and drug sensitivity in gefitinib-resistant non-small cell lung cancer cells

BACKGROUND

Resistance to gefitinib remains a major obstacle for the successful treatment of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. In this paper, we studied the precise actions of circular RNA (circRNA) microtubule actin crosslinking factor 1 (circ_MACF1) in gefitinib resistance.

METHODS

We established gefitinib-resistant NSCLC cells (PC9/GR and A549/GR). The levels of circ_MACF1, microRNA (miR)-942-5p, and transforming growth factor beta receptor 2 (TGFBR2) were gauged by quantitative real-time PCR (qRT-PCR) or western blot. Subcellular fractionation and Ribonuclease R (RNase R) assays were done to characterize circ_MACF1. Cell survival, proliferation, colony formation, apoptosis, migration, and invasion were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 5-Ethynyl-2'-Deoxyuridine (EdU), colony formation, flow cytometry, and transwell assays, respectively. Dual-luciferase reporter assays were used to verify the direct relationship between miR-942-5p and circ_MACF1 or TGFBR2. The xenograft assays were used to assess the role of circ_MACF1 in vivo.

RESULTS

Circ_MACF1 was down-regulated in A549/GR and PC9/GR cells. Overexpression of circ_MACF1 repressed proliferation, migration, invasion, and promoted apoptosis and gefitinib sensitivity of A549/GR and PC9/GR cells in vitro, as well as inhibited tumor growth under gefitinib in vivo. Circ_MACF1 directly targeted miR-942-5p, and miR-942-5p mediated the regulatory effects of circ_MACF1. TGFBR2 was identified as a direct and functional target of miR-942-5p. Circ_MACF1 modulated TGFBR2 expression through miR-942-5p.

CONCLUSION

Our findings demonstrated that circ_MACF1 regulated cell functional behaviors and gefitinib sensitivity of A549/GR and PC9/GR cells at least partially by targeting miR-942-5p to induce TGFBR2 expression.

LncRNA TMPO-AS1 facilitates the proliferation and metastasis of NSCLC cells by up-regulating ERBB2 via sponging miR-204-3p

Introduction:

This study aims at probing into the expression and biological function of long non-coding RNA (lncRNA) TMPO-AS1 in non-small cell lung cancer (NSCLC), and exploring its regulatory role for miR-204-3p and erb-b2 receptor tyrosine kinase 2 (ERBB2).

Methods:

In this study, paired NSCLC samples were collected, and the expression levels of TMPO-AS1, miR-204-3p and ERBB2 were examined by quantitative real-time polymerase chain reaction (qRT-PCR); proliferative ability and colony formation ability were detected by CCK-8 assay and plate colony formation assay, respectively; flow cytometry was performed to detect the effect of TMPO-AS1 on apoptosis; Transwell assay was used to detect the changes of migration and invasion; qRT-PCR and Western blot were utilised to analyse the changes of miR-204-3p and ERBB2 regulated by TMPO-AS1; luciferase reporter gene assay and RNA immunoprecipitation assay were employed to determine the regulatory relationship between TMPO-AS1 and miR-204-3p.

Results:

We demonstrated that TMPO-AS1 was significantly up-regulated in cancerous tissues of NSCLC samples, and positively correlated with the expression of ERBB2, while negatively correlated with miR-204-3p. After transfection of TMPO-AS1 shRNAs into NSCLC cells, the malignant phenotypes of NSCLC cells were significantly inhibited, while overexpression of TMPO-AS1 had opposite effects; TMPO-AS1 was also demonstrated to regulate the expression of miR-204-3p by sponging it, and indirectly modulate the expression of ERBB2.

Conclusion:

Collectively, we conclude that TMPO-AS1 has the potential to be the ‘ceRNA’ to regulate the expression of ERBB2 by sponging miR-204-3p in NSCLC.

MBNL1 Suppressed Cancer Metastatic of Skin Squamous Cell Carcinoma Via by TIAL1/MYOD1/Caspase-9/3 Signaling Pathways

OBJECTIVE

The incidence of skin squamous cell carcinoma (SSCC) has recently been increasing, with diverse clinical manifestations.SSCC could metastasize to lymph nodes or other organs, posing a great threat to life. The present study was designed to investigate the function and underlying mechanism of muscleblind-like protein 1 (MBNL1) in skin squamous cell carcinoma.

METHODS

SCL-1 cell was used for vitro model and transfected with MBNL1 or siMBNL1 plasmids. MTT Assays, LDH activity ELISA, and Transwell chamber migration experiment were used to confirm the effects of MBNL1 on cell growth of SCL-1 cell. Western blot analysis was used to analyze the mechanism of MBNL1 in SCL-1 cell.

RESULTS

Down-regulation of MBNL1 promoted cell metastasis of SSCC, while up-regulation of MBNL1 reduced cell metastasis of SSCC in vitro. Down-regulation of MBNL1 suppressed the protein expression of T cell intracellular antigen (TIAL1), myogenic determinant 1 (MyoD1) and Caspase-3 in vitro. Consistent with these observations, inhibition of TIAL1 or MYOD1 expression attenuated the effects of MBNL1 in SSCC.

CONCLUSION

The present study revealed that MBNL1 suppressed thecancer metastatic capacity of SSCC via by TIAL1/MYOD1/Caspase-3 signaling pathways.

Muscleblind-like 1 antisense RNA 1 inhibits cell proliferation, invasion, and migration of prostate cancer by sponging miR-181a-5p and regulating PTEN/PI3K/AKT/mTOR signaling

The present study aimed to investigate the role and underlying mechanisms of long non-coding RNA (lncRNA) muscleblind-like 1 antisense RNA 1 (MBNL1-AS1) in the progression of Prostate cancer (PCa). MBNL1-AS1 and microRNA (miR)-181a-5p expression in PCa tissues and several human PCa cell lines were analyzed, respectively, using StarBasev3.0 project and RT-qPCR assay. After MBNL1-AS1 overexpression, cell proliferation, invasion and migration were, respectively, evaluated using CCK-8, colony formation, transwell and wound healing assays. Dual luciferase assay were used for analysis of the interactions among MBNL1-AS1, miR-181a-5p, and phosphatase and tensin homolog (PTEN). Subsequently, the expression of PTEN and proteins in PI3K/AKT/mTOR signaling was examined using western blot analysis after transfection with miR-181a-5p mimic. The rescue assays were performed to investigate the effects of MBNL1-AS1 and miR-181a-5p on the functions of PCa cells and the expression of PTEN/PI3K/AKT/mTOR signaling by co-transfection with MBNL1-AS1 plasmid and miR-181a-5p mimic. Results indicated that MBNL1-AS1 was conspicuously downregulated while miR-181a-5p upregulating in PCa tissues and cell lines. MBNL1-AS1 overexpression decreased the abilities of cell proliferation, invasion, and migration. Further study revealed that MBNL1-AS1 acted as a sponge for miR-181a-5p and positively regulated PTEN by a sponge effect. Additionally, rescue assays proved that the effect of MBNL1-AS1-upregulation on the proliferation, invasion, and migration of PCa cells was dependent on miR-181a-5p. Furthermore, miR-181a-5p overexpression counteracted the expression of PTEN and proteins in PI3K/AKT/mTOR signaling exerted by MBNL1-AS1-upregulation in PCa cells. This study suggests that MBNL1-AS1 inhibits the progression of PCa via sponging miR-181a-5p and regulating PTEN/PI3K/AKT/mTOR pathway.

miR-301b-3p Regulates Breast Cancer Cell Proliferation, Migration, and Invasion by Targeting NR3C2

Objectives

Breast cancer is the most common malignant tumor among females, and miRNAs have been reported to play an important regulatory role in breast cancer progression. This study aimed to explore the function and underlying molecular mechanism of miR-301b-3p in breast cancer.

Methods

Differential analysis and survival analysis were performed based on the data accessed from the TCGA-BRCA dataset for identification of the target miRNA. Bioinformatics analysis was conducted to predict the downstream target gene of the miRNA. Real-time quantitative PCR was carried out to detect the expression of miR-301b-3p and nuclear receptor subfamily 3 group C member 2 (NR3C2). Western blot was used to assess the protein expression of NR3C2. Cell counting kit-8 assay was performed to evaluate the proliferation of breast cancer cells. Transwell assay was conducted to determine the migratory and invasive abilities of breast cancer cells. Dual-luciferase reporter assay was employed to verify the targeting relationship between miR-301b-3p and NR3C2.

Results

miR-301b-3p was elevated in breast cancer cell lines and promoted cell proliferation, migration, and invasion in terms of its biological function in breast cancer. NR3C2 was validated as a direct target of miR-301b-3p via bioinformatics analysis and dual-luciferase reporter assay, and NR3C2 was downregulated in breast cancer cell lines. The rescue experiment indicated that NR3C2 was involved in the mechanism by which miR-301b-3p regulated the malignant phenotype of breast cancer cells.

Conclusion

The present study revealed for the first time that miR-301b-3p could foster breast cancer cell proliferation, migration, and invasion by targeting NR3C2, unveiling that miR-301b-3p is a novel carcinogen in breast cancer.

LncRNA MBLN1-AS1 inhibits the progression of retinoblastoma through targeting miR-338-5p-Wnt/β-catenin signaling pathway

OBJECTIVE AND DESIGN

Retinoblastoma is the most common primary intraocular malignancy of childhood, which brings a heavy burden to the countries across the world, especially the developing countries. It has been shown that lncRNA muscleblind-like 1 antisense RNA 1 (MBNL1-AS1) exerts anti-tumor effects in various cancers, including bladder cancer, papillary thyroid cancer, and retinoblastoma. In the present study, we hypothesized that MBNL1-AS1 might play a protective role against retinoblastoma.

METHODS

The expression of MBNL1-AS1 and its potential target miR-338-5p were evaluated in retinoblastoma cell line by real-time quantitative PCR and western blot. The involvement of MBNL1-AS1-miR-338-5p in the cell proliferation was evaluated by cell counting kit-8 (CCK8), and colony formation assay. The cell migration was evaluated by Transwell assay in Y79 cells, a retinoblastoma cell line. The involvement of MBNL1-AS1-miR-338-5p in tumor formation was also evaluated in mice.

RESULTS

It was found that MBNL1-AS1 overexpression inhibited proliferation and migration in Y79 cells. In addition, the inhibitory effects of MBNL1-AS1 on Y79 cells were significantly reversed in the presence of miR-338-5p mimics, and MBNL1-AS1 overexpression significantly decreased miR-338-5p level in Y79 cells. Furthermore, MBNL1-AS1 overexpression significantly inhibited Wnt/β-catenin signaling pathway, and this inhibitory effect was almost lost in the presence of miR-338-5p mimics. Finally, our in vivo study showed that MBNL1-AS1 overexpression significantly inhibited Y79-induced retinoblastoma in mice, and this inhibitory effect was lost in the presence of miR-338-5p mimics.

CONCLUSION

Our study shows that MBNL1-AS1 exerts its anti-tumor effect by targeting miR-338-5p, thereby inactivating wnt/β-catenin signaling pathway in retinoblastoma.

MIR-301b-3p Promotes Lung Adenocarcinoma Cell Proliferation, Migration and Invasion by Targeting DLC1

BACKGROUND

miR-301b-3p is reported in various human cancers for its abnormal expression, while the role and molecular mechanisms in lung adenocarcinoma (LUAD) remain unclear, and this is the focus of the present study.

MATERIALS AND METHODS

TCGA database was consulted to know gene expression in LUAD tissue. CCK-8, colony formation assay and Transwell assay were applied to identify the role of target genes in regulating LUAD cell biological properties. Bioinformatics analysis plus dual-luciferase assay were performed to validate the potential connection between genes.

RESULTS

miR-301b-3p and DLC1 were the target genes of this study and respectively differentially up-regulated and down-regulated in LUAD. Functional experiments indicated that miR-301b-3p contributed to cancer cell proliferation, migration and invasion, while this effect was reversed with overexpressed DLC1 which was identified as a direct target of and regulated by miR-301b-3p.

CONCLUSIONS

Collectively, miR-301b-3p was identified to actively function on LUAD malignant progression by suppressing DLC1 expression. This discovery provides a novel therapeutic strategy for LUAD patients, which helps improve the survival of patients.

Identification of novel transcription factor-microRNA-mRNA co-regulatory networks in pulmonary large-cell neuroendocrine carcinoma

Background

Large cell neuroendocrine carcinoma (LCNEC) of the lung is a rare neuroendocrine neoplasm. Previous studies have shown that microRNAs (miRNAs) are widely involved in tumor regulation through targeting critical genes. However, it is unclear which miRNAs play vital roles in the pathogenesis of LCNEC, and how they interact with transcription factors (TFs) to regulate cancer-related genes.

Methods

To determine the novel TF-miRNA-target gene feed-forward loop (FFL) model of LCNEC, we integrated multi-omics data from Gene Expression Omnibus (GEO), Transcriptional Regulatory Relationships Unraveled by Sentence-Based Text Mining (TRRUST), Transcriptional Regulatory Element Database (TRED), and The experimentally validated microRNA-target interactions database (miRTarBase database). First, expression profile datasets for mRNAs (GSE1037) and miRNAs (GSE19945) were downloaded from the GEO database. Overlapping differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) were identified through integrative analysis. The target genes of the FFL were obtained from the miRTarBase database, and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses were performed on the target genes. Then, we screened for key miRNAs in the FFL and performed gene regulatory network analysis based on key miRNAs. Finally, the TF-miRNA-target gene FFLs were constructed by the hypergeometric test.

Results

A total of 343 DEGs and 60 DEMs were identified in LCNEC tissues compared to normal tissues, including 210 down-regulated and 133 up-regulated genes, and 29 down-regulated and 31 up-regulated miRNAs. Finally, the regulatory network of TF-miRNA-target gene was established. The key regulatory network modules included ETS1-miR195-CD36, TAOK1-miR7-1-3P-GRIA1, E2F3-miR195-CD36, and TEAD1-miR30A-CTHRC1.

Conclusions

We constructed the TF-miRNA-target gene regulatory network, which is helpful for understanding the complex LCNEC regulatory mechanisms.

Smoking load reduction is insufficient to downregulate miR-301b, a lung cancer promoter

Several circulating miRNAs identified in the plasma of smokers have been implicated as promoters of nasopharyngeal and lung carcinoma. To investigate the plasma profile of miRNAs in subjects who reduces the number of smoked cigarettes and who quit after six months. We accompanied 28 individuals enrolled in a Smoking Cessation Program over 6 months. At Baseline, clinical characteristics, co-morbidities, and smoking history were similar among subjects. After 6 months, two groups were defined: who successfully quitted smoking (named "quitters", n = 18, mean age 57 years, 11 male) and who reduced the number of cigarettes smoked (20-90%) but failed to quit smoking (named "smokers", n = 10, mean age 52 years, 3 male). No significant clinical changes were observed between groups at baseline and after a 6-month period, however, quitters showed significant downregulations in seven miRNAs at baseline: miR-17 (- 2.90-fold, p = 0.029), miR-20a (- 3.80-fold, p = 0.021); miR-20b (- 4.71-fold, p = 0.027); miR-30a (- 3.95-fold, p = 0.024); miR-93 (- 3.63-fold, p = 0.022); miR-125a (- 1.70-fold, p = 0.038); and miR-195 (- 5.37-fold, p = 0.002), and after a 6-month period in 6 miRNAs: miR-17 (- 5.30-fold, p = 0.012), miR-20a (- 2.04-fold, p = 0.017), miR-20b (- 5.44-fold, p = 0.017), miR-93 (- 4.00-fold, p = 0.041), miR-101 (- 4.82-fold, p = 0.047) and miR-125b (- 3.65-fold, p = 0.025). Using time comparisons, only quitters had significant downregulation in miR-301b (- 2.29-fold, p = 0.038) after 6-month. Reductions in the number of smoked cigarettes was insufficient to change the plasma profile of miRNA after 6 months. Only quitting smoking (100% reduction) significantly downregulated miR-301b related to hypoxic conditions, promotion of cell proliferation, decreases in apoptosis, cancer development, and progression as increases in radiotherapy and chemotherapy resistance.

SLC16A1-AS1 enhances radiosensitivity and represses cell proliferation and invasion by regulating the miR-301b-3p/CHD5 axis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), a common type of human malignancies, leads to increasing incidence and fairly high mortality. An increasing number of studies have verified that long noncoding RNAs (lncRNAs) played key roles in the development of multiple human cancers. As a biomarker, SLC16A1-AS1 has been reported in non-small cell lung cancer (NSCLC) and oral squamous cell carcinoma (OSCC). Thus, we decided to investigate whether SLC16A1-AS1 exerts its biological function in HCC. In this study, we discovered that SLC16A1-AS1 was obviously downregulated in HCC tissues and cells. Overexpression of SLC16A1-AS1 inhibited HCC cell proliferation, invasion, and epithelial-mesenchymal transition (EMT) process as well as promoted cell apoptosis. Moreover, SLC16A1-AS1 was confirmed to enhance the radiosensitivity of HCC cells. Molecular mechanism exploration suggested that SLC16A1-AS1 served as a sponge for miR-301b-3p and CHD5 was the downstream target gene of miR-301b-3p in HCC cells. Rescue assays implied that CHD5 knockdown could recover the effects of SLC16A1-AS1 overexpression on HCC cellular processes. In brief, our study clarified that SLC16A1-AS1 acted as a tumor suppressor in HCC by targeting the miR-301b-3p/CHD5 axis, which may be a promising diagnostic biomarker and provide promising treatment for HCC patients.

Long Noncoding RNA PTPRG Antisense RNA 1 Reduces Radiosensitivity of Nonsmall Cell Lung Cancer Cells Via Regulating MiR-200c-3p/TCF4

Background:

PTPRG antisense RNA 1 has been well-documented to exert an oncogenic role in diverse neoplasms. However, the precise role of PTPRG antisense RNA 1 in regulating radiosensitivity of nonsmall cell lung cancer cells remains largely elusive.

Methods:

Expression levels of PTPRG antisense RNA 1 and miR-200c-3p in nonsmall cell lung cancer tissues and cells were detected by quantitative real-time polymerase chain reaction, while transcription factor 4 expression was examined by immunohistochemistry and Western blot. After nonsmall cell lung cancer cells were exposed to X-ray with different doses in vitro, Cell Counting Kit-8 assay and colony formation assay were conducted to determine the influence of PTPRG antisense RNA 1 on cell viability. Interaction between miR-200c-3p and PTPRG antisense RNA 1 as well as transcription factor 4 was investigated by dual luciferase reporter assay.

Result:

In nonsmall cell lung cancer tissues, the expressions of PTPRG antisense RNA 1 and transcription factor 4 were significantly upregulated, whereas the expression of miR-200c-3p was downregulated. It was also proved that PTPRG antisense RNA 1 and 3′-untranslated region of transcription factor 4 can bind to miR-200c-3p. Under X-ray irradiation, overexpressed PTPRG antisense RNA 1 could promote the viability and enhance the radioresistance of nonsmall cell lung cancer cells, and this effect was partially weakened by miR-200c-3p mimics. Transcription factor 4 was identified as a target gene of miR-200c-3p, which could be positively regulated by PTPRG antisense RNA 1.

Conclusion:

PTPRG antisense RNA 1 reduces the radiosensitivity of nonsmall cell lung cancer cells via modulating miR-200c-3p/TCF4 axis.

The functional role of long non-coding RNAs and their underlying mechanisms in drug resistance of non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is the most commonly diagnosed solid cancer and the main origin of cancer-related deaths worldwide. Current strategies to treat advanced NSCLC are based on a combined approach of targeted therapy and chemotherapy. But most patients will eventually get resistance to either chemotherapy or targeted therapy, leading to the poor prognosis. The mechanism of NSCLC drug resistance is inconclusive and is affected by multiple factors. Long non-coding RNAs (LncRNAs) are non-coding RNAs (ncRNAs) longer than 200 nucleotides. Recent studies show that lncRNAs are involved in many cellular physiological activities, including drug resistance of NSCLC. It is of great clinical significance to understand the specific mechanisms and the role of lncRNAs in it.

CONCLUSIONS

Herein, we focus on the functional roles and the underlying mechanisms of lncRNAs in acquired drug resistance of NSCLC. LncRNAs have potential values as novel prognostic biomarkers and even therapeutic targets in the clinical management of NSCLC.

Long noncoding RNAs, ENST00000598996 and ENST00000524265, are correlated with favorable prognosis and act as potential tumor suppressors in bladder cancer

Bladder cancer (BC) is a serious malignancy worldwide due to its distant metastasis and high recurrence rates. Increasing evidence has indicated that dysregulated long non-coding RNAs (lncRNAs) are involved in tumorigenesis and progression in multiple malignancies. However, their clinical significances, biological functions and molecular mechanisms in BC remain poorly understood. Hence, the present study investigated the expression profile of lncRNAs and mRNAs in five BC tissues and the corresponding adjacent normal specimens using high-throughput RNA sequencing (RNA-seq). A total of 103 differentially expressed (DE) lncRNAs were identified, including 35 upregulated and 68 downregulated ones in BC tissues. Similarly, a total of 2,756 DE-mRNAs were detected, including 1,467 upregulated and 1,289 downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses, and lncRNA-miRNA-mRNA network analyses suggested that these dysregulated lncRNAs are potentially implicated in the onset and progression of BC. Subsequently, four lncRNAs (upregulated ENST00000433108; downregulated ENST00000598996, ENST00000524265 and ENST00000398461) and two mRNAs (upregulated CCNB1 and CDK1) in 64 pairs of BC and adjacent normal tissues and four BC cell lines were detected using reverse transcription-quantitative PCR and these results were consistent with the sequencing data. Additionally, Fisher's exact test, Kaplan-Meier plots, and Cox regression analyses were used for elucidating the clinical values of ENST00000598996 and ENST00000524265. Furthermore, a receiver operating characteristic curve was constructed to assess their diagnostic values. The low expression level of ENST00000598996 and ENST00000524265 was correlated with unfavorable clinicopathological parameters, and shorter progression-free and overall survival time, whereas, ENST00000433108 was not associated with either. The in vitro functional experiments also revealed that the overexpression of ENST00000598996 and ENST00000524265 decreased the proliferation, migration, and invasion abilities of BC cells. Collectively, the results of the present study provide a novel landscape of lncRNA and mRNA expression profiles in BC. In addition, the results also indicated that ENST00000598996 and ENST00000524265 may serve as tumor suppressors, potential diagnostic biomarkers and prognostic predictors for patients with BC.

MicroRNA-301b and its target gene synaptosome-associated protein 91 as important modulators in esophageal cancer: functional experiments

The aim of this study was to probe the influence of microRNA-301b (miR-301b) in esophageal cancer pathogenesis. Based on the data acquired from The Cancer Genome Atlas database, we found that miR-301b was highly expressed in esophageal cancer tissues and high expression of miR-301b was related to worse prognosis in patients with esophageal cancer. Quantitative real-time PCR revealed that the expression of miR-301b was higher in all examined esophageal cancer cell lines (ECA109, KY-SE150, TE-1, and NEC) than that in a human esophageal epithelial cell line (HEEC). Upregulation/downregulation of miR-301b facilitated/suppressed the growth, migration, and invasion of ECA109/KY-SE150 cells. Synaptosome-associated protein 91 (SNAP91) was proved to be one of the target genes of miR-301b and was negatively modulated by miR-301b. Besides, SNAP91 was lowly expressed in human esophageal cancer tissues and cell lines. Meanwhile, low expression of SNAP91 was concerned with poor prognosis in patients with esophageal cancer. Furthermore, we discovered that overexpression/depletion of SNAP91 suppressed/facilitated the proliferation of KY-SE150/ECA109 cells. MiR-301b and SNAP91 had little impact on HEEC cell proliferation and this degree of influence was negligible compared with their impacts on esophageal cancer cell proliferation. By rescue assay, we showed that overexpression of SNAP91 restrained the growth, migration, and invasion of ECA109 cells with overexpressed miR-301b while knockdown of SNAP91 showed the contrary effects on KY-SE150 cells with downregulated miR-301b. These consequences indicated that miR-301b played an important effect on esophageal cancer cells through regulating SNAP91, insinuating that miR-301b/SNAP91 might be novel potential targets for esophageal cancer therapy and prognosis.

MiR-362-5p, Which Is Regulated by Long Non-Coding RNA MBNL1-AS1, Promotes the Cell Proliferation and Tumor Growth of Bladder Cancer by Targeting QKI

In this study, we found miR-362-5p was upregulated in bladder cancer tissues and we predicted that QKI is potential a target of miR-362-5p and MBNL1-AS1 might be able to directly target to miR-362-5p. We attempted to evaluate whether miR-362-5p could play its roles in bladder cancer through regulating QKI (quaking) and whether the expression and function of miR-362-5p could be mediated by lncRNA MBNL1-AS1. We performed the gain- and loss-function experiments to explore the association between miR-362-5p expression and bladder cancer proliferation. In vivo, the nude mice were injected with miR-362-5p knockdown SW780 cells to assess the effects of miR-362-5p on tumor growth. The results showed upregulation of miR-362-5p promoted cell proliferation of bladder cancer cells. MBNL1-AS1 and QKI could directly bind with miR-362-5p, and knockdown of MBNL1-AS1 or QKI could abrogate the regulatory effects of miR-362-5p on bladder cancer cell proliferation. Furthermore, downregulation of miR-362-5p inhibited bladder tumor growth and increased QKI expression. Our data unveiled that miR-362-5p may play an oncogenic role in bladder cancer through QKI and MBNL1-AS1 might function as a sponge to mediate the miR-362-5p expression and function.

Down-regulation of MBNL1-AS1 contributes to tumorigenesis of NSCLC via sponging miR-135a-5p

Lung cancer remains a big threat to human health. Growing evidence has reported the crucial regulatory effect of lncRNAs on NSCLC progression. Nevertheless, the detailed function of lncRNA MBNL1-AS1 involved in NSCLC development is poorly known. In our research, we confirmed that MBNL1-AS1 was significantly reduced in NSCLC patient tissues and NSCLC cells. Meanwhile, we reported that overexpression of MBNL1-AS1 obviously repressed A549 and H1975 cell proliferation, blocked cell cycle and inhibited the migration and invasion. Moreover, A549 and H1975 cell apoptosis was increased by the overexpression of MBNL1-AS1. Then, we predicted that miR-135a-5p was a potential target of MBNL1-AS1 and its level was correlated with MBNL1-AS1 in NSCLC negatively. Our previous study indicated miR-135a-5p could induce lung cancer progression through regulating LOXL4. Here, we found that MBNL1-AS1 was able to regulate miR-135a-5p expression negatively. The direct binding association between MBNL1-AS1 and miR-135a-5p was proved using dual-luciferase reporter assay and RIP experiment. Subcutaneous xenotransplanted tumor model was set up and it was confirmed increased MBNL1-AS1 remarkably restrained tumorigenic ability of NSCLC through sponging miR-135a-5p in vivo. To sum up, our data revealed the significance of the MBNL1-AS1 and miR-135a-5p in NSCLC. In conclusion, MBNL1-AS1 could be a new therapeutic target to treat NSCLC.

Down-Regulation of LINC00460 Represses Metastasis of Colorectal Cancer via WWC2

BACKGROUND

Colorectal cancer (CRC) is one of the most prevalent cancers and a common cause of cancer-related death. Long noncoding RNAs have been reported to play an essential role in the development of CRC.

AIMS

This study aimed to investigate the possible function of LINC00460 in CRC.

METHODS

Initially, microarray-based gene expression profiling of CRC was employed to identify differentially expressed genes. Next, the expression of LINC00460 was examined and the cell line presenting with the highest LINC00460 expression was selected for subsequent experimentation. Then, the interaction among LINC00460, ERG, and WWC2 was identified. The effect of LINC00460 on proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT)-related factors as well as tumorigenicity of transfected cells was examined with gain- and loss-of-function experiments.

RESULTS

LINC00460 was robustly induced while WWC2 was poorly expressed in CRC. In addition, LINC00460 could down-regulate WWC2 through interaction with ERG, which led to promoted invasion, migration, and EMT of CRC cells in addition to tumor growth in vivo. Besides, down-regulation of LINC00460 exerted inhibitory effect on these biological activities.

CONCLUSION

Taken together, the key findings of the current study provided evidence suggesting that silencing of LINC00460 could potentially suppress EMT of CRC cells by increasing WWC2 via ERG, and highlighting that knockdown of LINC00460 could serve as a therapeutic target for CRC treatment.

KCNQ1OT1 aggravates cell proliferation and migration in bladder cancer through modulating miR-145-5p/PCBP2 axis

Background

The large involvement of long non-coding RNAs (LncRNAs) in the biological progression of numerous cancers has been reported. The function of lncRNA KCNQ1OT1 in bladder cancer (BC) remains largely unknown. This study aimed to explore the critical role of KCNQ1OT1 in BC.

Materials and methods

The qRT-PCR was applied to test the expression of RNAs. Cell proliferation was detected by CCK-8 and colony formation assays. Cell apoptosis was measured by TUNEL and flow cytometry experiments. Wound healing and transwell assays were employed to evaluate cell migration and invasion ability respectively. Western blot assay was used to measure relevant protein expression. Immunofluorescence (IF) staining was used to observe EMT process in BC.

Results

KCNQ1OT1 was significantly overexpressed in BC tissue and cell lines. KCNQ1OT1 depletion repressed cell proliferation, migration and invasion, whereas encouraged cell apoptosis. KCNQ1OT1 was a negatively/positively correlated with miR-145-5p/PCBP2 in respect with expression. Mechanically, KCNQ1OT1 was sponge of miR-145-5p and up-regulated the expression of PCBP2. MiR-145-5p inhibition and PCBP2 up-regulation could countervail the tumor-inhibitor role of KCNQ1OT1 knockdown in BC.

Conclusion

KCNQ1OT1 serves as competing endogenous RNA (ceRNA) to up-regulate PCBP2 via sponging miR-145-5p in BC progression.

LncRNA MBNL1-AS1 represses cell proliferation and enhances cell apoptosis via targeting miR-135a-5p/PHLPP2/FOXO1 axis in bladder cancer

LncRNAs have been shown to play essential roles in bladder cancer (BC) progress. Our microarrays of clinical samples firstly screened that lncRNA muscleblind‐like 1 antisense RNA 1 (MBNL1‐AS1) was poorly expressed in BC tissues. However, its biological function in BC remains not well understood. Here we examined the clinical correlations with MBNL1‐AS1 in BC patients. Then, 5673 and T24 cell lines were employed to investigate the role of MBNL1‐AS1 in the proliferation and apoptosis of BC cells in vitro and in vivo. Furthermore, miR‐135a‐5p (miR‐135a)/PHLPP2/FOXO1 axis was focused to explore its regulatory mechanism in BC. The results showed that MBNL1‐AS1 was significantly downregulated in bladder tumor tissues, and associated with BC progression. In vitro, MBNL1‐AS1 knockdown increased the number of viable cells and bromodeoxyuridine‐positive cells, accelerated cell cycle, and dysregulated proliferative regulators (Ki67, p21, p27, and Cyclin D1) in BC cells. The apoptotic cells and the cleavages of caspase‐3/9 were reduced in MBNL1‐AS1‐silenced BC cells. Overexpression of MBNL1‐AS1 had opposite effects on BC cell proliferation and apoptosis. Moreover miR‐135a was demonstrated to interact with MBNL1‐AS1, and inhibiting miR‐135a reversed the effects of shMBNL1‐AS1 on BC cells. The downstream effectors (PHLPP2 and FOXO1) were positively regulated by MBNL1‐AS1, but negatively regulated by miR‐135a. Similar results were also observed in xenograft tumors. In conclusion, this study firstly suggests that MBNL1‐AS1 acts as a tumor suppressor of BC by targeting miR‐135a/PHLPP2/FOXO1 axis, providing a novel insight for BC diagnosis and treatment.

MicroRNA-301b-3p accelerates the growth of gastric cancer cells by targeting zinc finger and BTB domain containing 4

MicroRNAs (miRNAs) have been found to be aberrantly expressed and exert essential roles in the tumorigenesis and progression of gastric cancer (GC). miR-301b-3p has been recognized as a cancer-related miRNA in lung cancer, bladder cancer and hepatocellular carcinoma. However, the function of miR-301b-3p in GC progression and its underlying mechanism have not been studied yet. In this study, we found that miR-301b-3p expression was up-regulated in GC tissues compared to adjacent noncancerous tissues. Furthermore, the elevated levels of miR-301b-3p were detected in GC cell lines (SGC-7901, AGS, MKN-45 and MGC-803) as compared with GES-1 cells. Interestingly, GC tissues from patients with tumor size ≥ 5 cm and advanced tumor stages showed obvious higher levels of miR-301b-3p compared to matched controls. Functionally, miR-301b-3p knockdown prominently inhibited cell proliferation, and induced cell cycle arrest at G1 phase and apoptosis in MGC-803 cells. Meanwhile, ectopic expression of miR-301b-3p conversely regulated these biological behaviors of MKN-45 cells. Next, we found that miR-301b-3p knockdown increased, whereas miR-301b-3p overexpression reduced the expression of zinc finger and BTB domain containing 4 (ZBTB4) in GC cells. Accordingly, luciferase reporter assay identified ZBTB4 as a direct target of miR-301b-3p. ZBTB4 overexpression markedly restrained the growth of MGC-803 cells. More importantly, ZBTB4 silencing partially reversed miR-301b-3p knockdown-induced tumor suppressive effects on MGC-803 cells. In conclusion, we firstly revealed that miR-301-3p was highly expressed in GC and contributed to tumor progression via attenuating ZBTB4, which might provide a novel molecular-targeted strategy for GC treatment.