MiR-876-5p acts as an inhibitor in hepatocellular carcinoma progression by targeting DNMT3A

From molecular pathogenesis to therapy: Unraveling non-coding RNAs/DNMT3A axis in human cancers

Cancer is a comprehensive classification encompassing more than 100 forms of malignancies that manifest in diverse tissues within the human body. Recent studies have provided evidence that aberrant epigenetic modifications are pivotal indicators of cancer. Epigenetics encapsulates DNA methyltransferases as a crucial class of modifiers. DNMTs, including DNMT3A, assume central roles in DNA methylation processes that orchestrate normal biological functions, such as gene transcription, predominantly in mammals. Typically, deviations in DNMT3A function engender distortions in factors that drive tumor growth and progression, thereby exacerbating the malignant phenotype of tumors. Consequently, such abnormalities pose significant challenges in cancer therapy because they impede treatment efficacy. Non-coding RNAs (ncRNAs) represent a group of RNA molecules that cannot encode functional proteins. Recent investigation attests to the crucial significance of regulatory ncRNAs in epigenetic regulation. Notably, recent reports have illuminated the complex interplay between ncRNA expression and epigenetic regulatory machinery, including DNMT3A, particularly in cancer. Recent findings have demonstrated that miRNAs, namely miR-770-5p, miR-101, and miR-145 exhibit the capability to target DNMT3A directly, and their aberration is implicated in diverse cellular abnormalities that predispose to cancer development. This review aims to articulate the interplay between DNMT3A and the ncRNAs, focusing on its impact on the development and progression of cancer, cancer therapy resistance, cancer stem cells, and prognosis. Importantly, the emergence of such reports that suggest a connection between DNMT3A and ncRNAs in several cancers indicates that this connecting axis offers a valuable target with significant therapeutic potential that might be exploited for cancer management.

Harnessing function of EMT in hepatocellular carcinoma: From biological view to nanotechnological standpoint

Management of cancer metastasis has been associated with remarkable reduction in progression of cancer cells and improving survival rate of patients. Since 90% of mortality are due to cancer metastasis, its suppression can improve ability in cancer fighting. The EMT has been an underlying cause in increasing cancer migration and it is followed by mesenchymal transformation of epithelial cells. HCC is the predominant kind of liver tumor threatening life of many people around the world with poor prognosis. Increasing patient prognosis can be obtained via inhibiting tumor metastasis. HCC metastasis modulation by EMT and HCC therapy by nanoparticles are discussed here. First of all, EMT happens during progression and advanced stages of HCC and therefore, its inhibition can reduce tumor malignancy. Moreover, anti-cancer compounds including all-trans retinoic acid and plumbaging, among others, have been considered as inhibitors of EMT. The EMT association with chemoresistance has been evaluated. Moreover, ZEB1/2, TGF-β, Snail and Twist are EMT modulators in HCC and enhancing cancer invasion. Therefore, EMT mechanism and related molecular mechanisms in HCC are evaluated. The treatment of HCC has not been only emphasized on targeting molecular pathways with pharmacological compounds and since drugs have low bioavailability, their targeted delivery by nanoparticles promotes HCC elimination. Moreover, nanoparticle-mediated phototherapy impairs tumorigenesis in HCC by triggering cell death. Metastasis of HCC and even EMT mechanism can be suppressed by cargo-loaded nanoparticles.

circRPS16 Promotes Proliferation and Invasion of Hepatocellular Carcinoma by Sponging miR-876-5p to Upregulate SPINK1

The roles of serine protease inhibitor Kazal type 1 (SPINK1) in multiple types of cancers have been significantly documented. However, its specific roles in hepatocellular carcinoma (HCC) remain to be investigated. This study found that SPINK1 is upregulated in HCC and its upregulation correlates with poor prognosis. Besides, functional assays revealed that SPINK1 promotes cell proliferation, cell cycle, and invasion in vitro. Through bioinformatics analysis, we speculate that circRPS16 regulates SPINK1 expression by sponging miR-876-5p. This was further verified by the dual-luciferase reporter and fluorescent in situ hybridization (FISH) assays. Subsequently, rescue assays verified that circRPS16 promotes cell proliferation, cell cycle, and invasion through miR-876-5p. Importantly, silencing circRPS16 inhibited tumor growth by downregulating SPINK1 expression in vivo. Collectively, our results confirm that SPINK1 is a downstream target of circRPS16. Besides, circRPS16 and SPINK1 are oncogenic factors in HCC progression; they provide novel diagnostic and therapeutic targets for HCC patients.

Long non-coding RNA HCP5 functions as a sponge of miR-29b-3p and promotes cell growth and metastasis in hepatocellular carcinoma through upregulating DNMT3A

Multiple studies have revealed that long non-coding RNA (lncRNAs) served as regulatory factors in modulating tumorigenesis of hepatocellular carcinoma (HCC). In the present study, we demonstrated that lncRNA HCP5 was overexpressed in HCC tissues and cell lines, and these findings were obvious even in metastatic and recurrent cases. Knockdown of HCP5 significantly alleviated cell growth, metastasis, and invasion both in vitro and in vivo through promoting apoptosis and by inactivating the epithelial-mesenchymal transition (EMT) progress. Moreover, miR-29b-3p has been identified as a negatively regulatory target gene of HCP5, and served as a tumor suppressor of HCC to prevent cell proliferation, migration, and invasion. Subsequently, DNMT3A was identified as a downstream regulatory factor of miR-29b-3p, and acted as a participated element of HCC progression by activating AKT phosphorylation. Taken together, our study elucidated for the first time that HCP5 plays a crucial role in HCC via the HCP5/miR-29b-3p/DNMT3A/AKT axis and our findings demonstrated a novel diagnostic and therapeutic strategy with potentiality to treat HCC.

miR-876 Inhibits EMT and Liver Fibrosis via POSTN to Suppress Metastasis in Hepatocellular Carcinoma

Background

The asymptomatic onset, frequent recurrence, and poor prognosis of hepatocellular carcinoma (HCC) prompted us to identify new therapeutic targets or predictive markers of HCC diagnosis or prognosis.

Methods

In this study, bioinformatics analysis was used to screen for target miRNAs from the open-access TCGA database. Transwell assays, Western blotting, and qRT-PCR analyses were used to detect cellular functions and gene expression in HCC cells and samples. A nude mouse tumorigenesis model was established to facilitate the observation of HCC progression. Other assays included luciferase reporter assays, IHC, and survival analysis.

Results

We found that the identified miR-876 from TCGA was expressed at low levels in HCC cell lines and that low miR-876 expression was corrected with liver cirrhosis, tumor thrombus, and TNM stage. Further research revealed that miR-876 regulated cell invasion, EMT, and collagen expression by targeting POSTN expression. miR-876 and POSTN were inversely correlated in HCC samples and associated with EMT status and liver fibrosis in clinical HCC tissues. miR-876 inhibited the liver cancer progression in in vivo animal assays. Finally, both miR-876 and POSTN were risk factors for HCC survival, and HCC patients with combined low miR-876 and high POSTN expression had worse prognosis.

Conclusions

miR-876 inhibited HCC EMT and fibrosis by targeting POSTN, thus affecting HCC progression and prognosis. miR-876 and POSTN may be useful therapeutic targets or prognostic markers of HCC.

SNHG17 drives malignant behaviors in astrocytoma by targeting miR-876-5p/ERLIN2 axis

Background

Astrocytoma is a common tumor type in primary central nervous system and has a high death rate around the world. Aberrant expression of long non-coding RNAs (lncRNAs) has been introduced by emerging studies to result in the development of diverse cancers.

Methods

RT-qPCR examined the expression of SNHG17, miR-876-5p and ERLIN2, and western blot evaluated ERLIN2 protein level. RNA pull down and luciferase reporter assays illustrated the relationships between SNHG17 and its downstream molecules.

Results

SNHG17 was up-regulated in astrocytoma cells. Moreover, SNHG17 silence could repress the proliferation, migration and invasion of astrocytoma cells. Besides, miR-876-5p was selected out as a downstream molecule of SNHG17 in astrocytoma. ERLIN2 was determined to be targeted by miR-876-5p. ERLIN2 mRNA and protein levels were lessened by miR-876-5p overexpression and SNHG17 silence. Additionally, miR-876-5p overexpression decelerated the biological processes of astrocytoma cells, so did ERLIN2 knockdown. More importantly, the impacts of SNHG17 down-regulation on the malignant behaviors of astrocytoma cells were counteracted by overexpressed ERLIN2 or inhibited miR-876-5p.

Conclusions

SNHG17 could induce the progression of astrocytoma by sponging miR-876-5p to elevate the expression of ERLIN2. This study indicated that SNHG17 has a high potential to be a therapeutic target for astrocytoma.

CircHIPK3/miR-876-5p/PIK3R1 axis regulates regulation proliferation, migration, invasion, and glutaminolysis in gastric cancer cells

BACKGROUND

Circular RNAs (circRNAs) are a new group of non-coding RNAs that play vital roles in cancer occurrence, including gastric cancer (GC). Nevertheless, the role and underlying regulatory mechanisms of circHIPK3 in GC remain unclear.

METHODS

The expression levels of circHIPK3, miR-876-5p, and phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) were estimated by real-time quantitative polymerase chain reaction (RT-qPCR) assay. The proliferation, migration, and invasion of GC cells were determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT) and transwell assay. Glutaminolysis of GC cells was assessed by measuring glutamine, glutamate, and α-ketoglutarate levels. The western blot was employed to examine the related-protein expression. The association between miR-876-5p and circHIPK3 or PIK3R1 was predicted and affirmed by bioinformatics database starBase v2.0 and dual-luciferase reporter assay, respectively. Eventually, the xenograft experiment was used to assess the role of circHIPK3 silencing in vivo.

RESULTS

CircHIPK3 was upregulated in GC tissues and cells compared with controls, and circHIPK3 was more resistance to RNase R than linear homeodomain interacting protein kinase 3 (HIPK3) mRNA. Silencing of circHIPK3 inhibited GC cells proliferation, migration, invasion, and glutaminolysis as well as tumor tumorigenic ability. Moreover, we also found that miR-876-5p, interacted with PIK3R1, was a target gene of circHIPK3. CircHIPK3 silencing induced effects on GC cells were abolished by silencing of miR-876-5p. In addition, upregulation of PIK3R1 inversed miR-876-5p overexpression-induced effects on GC cells.

CONCLUSION

The circHIPK3 mediated the proliferation, migration, invasion, and glutaminolysis of GC cells partly through regulation of miR-876-5p/PIK3R1 axis by the mechanism of competing endogenous RNAs (ceRNA), indicating circHIPK3 was a GC-associated circRNA that promoted GC development.

Regulation of DNA methylation machinery by epi-miRNAs in human cancer: emerging new targets in cancer therapy

Disruption in DNA methylation processes can lead to alteration in gene expression and function that would ultimately result in malignant transformation. In this way, studies have shown that, in cancers, methylation-associated silencing inactivates tumor suppressor genes, as effectively as mutations. DNA methylation machinery is composed of several genes, including those with DNA methyltransferases activity, proteins that bind to methylated cytosine in the promoter region, and enzymes with demethylase activity. Based on a prominent body of evidence, DNA methylation machinery could be regulated by microRNAs (miRNAs) called epi-miRNAs. Numerous studies demonstrated that dysregulation in DNA methylation regulators like upstream epi-miRNAs is indispensable for carcinogenesis; consequently, the malignant capacity of these cells could be reversed by restoring of this regulatory system in cancer. Conceivably, recognition of these epi-miRNAs in cancer cells could not only reveal novel molecular entities in carcinogenesis, but also render promising targets for cancer therapy. In this review, at first, we have an overview of the methylation alteration in cancers, and the effect of this phenomenon in miRNAs expression and after that, we conduct an in-depth discussion about the regulation of DNA methylation regulators by epi-miRNAs in cancer cells.

MCM3AP-AS1/miR-876-5p/WNT5A axis regulates the proliferation of prostate cancer cells

BACKGROUND

Although the fact that long non-coding RNA MCM3AP antisense RNA 1 (MCM3AP-AS1) is oncogenic in several cancers is well documented, very few researchers investigate its expression and function in prostate cancer.

METHODS

Paired prostate cancer samples were selected, and expressions of MCM3AP-AS1, miR-876-5p and WNT5A were examined by qRT-PCR. MCM3AP-AS1 shRNA was transfected into LNCaP and PC-3 cell lines, and then the proliferative activity and apoptosis of cancer cells were detected by CCK-8 assay, EdU assay and flow cytometry analysis, respectively. qRT-PCR and Western blot were used to analyze the changes of miR-876-5p and WNT5A. Luciferase reporter gene assay was employed to determine the regulatory relationship between miR-876-5p and MCM3AP-AS1, miR-876-5p and WNT5A.

RESULTS

MCM3AP-AS1 was significantly up-regulated in cancerous tissues of prostate cancer samples, positively correlated with the expression of WNT5A, while negatively related with miR-876-5p. After transfection of MCM3AP-AS1 shRNA into prostate cancer cells, the proliferative ability of cancer cells was signally inhibited, but the apoptosis of cancer cells was increased. MCM3AP-AS1 shRNA could reduce the expression of WNT5A on both mRNA and protein levels. Besides, MCM3AP-AS1 was identified as a sponge of miR-876-5p. WNT5A was validated as a target gene of miR- 876-5p.

CONCLUSION

MCM3AP-AS1 is abnormally up-regulated in prostate cancer tissues and can modulate the proliferation and apoptosis of prostate cancer cells, which has the potential to be the "ceRNA" to regulate the expression of WNT5A by targeting miR-876-5p.

Tumor suppressor role of miR-876-5p in gastric cancer

Gastric cancer (GC) is the second most common cancer cause of cancer-related mortality worldwide. Recent studies have demonstrated the function of microRNAs (miRNAs) in the pathogenesis of GC. miR-876-5p demonstrated an antitumor role in hepatocellular carcinoma and lung cancer; however, the function of miR-876-5p has not yet been fully identified in GC. Thus, the present study aimed to investigate the role of miR-876-5p in GC. The results of the present study demonstrated low expression levels of miR-876-5p in GC tumor tissues. Furthermore, overexpression of miR-876-5p inhibited GC cell proliferation and promoted apoptosis, whilst miR-876-5p knockdown promoted GC cell proliferation and decreased cisplatin sensitivity of GC cells. Transforming growth factor β-receptor 1 was demonstrated to be a potential target gene of miR-876-5p. Overall, the results of the present study suggest that miR-876-5p plays an antitumor role in GC.

Long noncoding RNA PITPNA-AS1 promotes cervical cancer progression through regulating the cell cycle and apoptosis by targeting the miR-876-5p/c-MET axis

Cervical cancer is a common tumor type and a leading cause of tumor death among female in the world. However, the molecular mechanisms revealing the cervical cancer progression have not been fully investigated. Long noncoding RNA (LncRNA) PITPNA-AS1 is a newly found lncRNA, showing the promoting role in tumor growth. But its effects on cervical cancer development still remain unknown. In the study, we found that PITPNA-AS1 was markedly increased in human cervical cancer tissues and cell lines. PITPNA-AS1 over-expression elevated the proliferation of cervical cancer cells, whereas PITPNA-AS1 knockdown reduced the cell proliferation. Moreover, PITPNA-AS1 knockdown markedly accelerated the G0/G1 and reduced the G2/M phase transitions through decreasing the cyclin-dependent kinase (CDK)-2/4/6 and CyclinD1 expression levels. In addition, apoptosis was significantly induced by PITPNA-AS1 knockdown in cervical cancer cells. Importantly, PITPNA-AS1 was identified as the sponge of miR-876-5p, and a negative correlation was detected between PITPNA-AS1 and miR-876-5p in cervical cancer samples. Moreover, tyrosine-protein kinase MET (c-MET) was identified to be a down-streaming target gene of miR-876-5p in cervical cancer cells. PITPNA-AS1 meditated the effects of c-MET on the proliferation, apoptosis and cell cycle in cervical cancer cells by adsorbing miR-876-5p. In summary, targeting the PITPNA-AS1-associated signaling could be a therapeutic strategy for the treatment of cervical cancer.

Long Non-coding RNA MINCR Regulates miR-876-5p/GSPT1 Axis to Aggravate Glioma Progression

Emerging evidence underlined the crucial roles played by long non-coding RNAs (lncRNAs) in glioma. MINCR has been reported in multiple malignancies. Here, we studied its function and potential mechanism in glioma, which remain unclear. Gene expressions were analyzed by qRT-PCR assay. Both in vitro and in vivo assays were conducted to evaluate the cellular function of MINCR in glioma. The subcellular situation of MINCR was detected by subcellular fractionation and FISH assays. Luciferase reporter, RNA pull-down and RNA immunoprecipitation (RIP) assays were combined to investigate potential mechanisms of relevant genes. MINCR was up-regulated in glioma. MINCR depletion markedly refrained glioma cell proliferation, migration and invasion via sponging miR-876-5p. MiR-876-5p suppressed the malignant behaviors of glioma via binding to GSPT1. MINCR shared the binding sites with the 3'-untranslated region of GSPT1 and prevented the binding of miR-876-5p to GSPT1 mRNA, thus up-regulating the level of GSPT1. Moreover, miR-876 inhibition and GSPT1 up-regulation counteracted the functional effect induced by silencing MINCR on glioma progression. Our findings uncovered that MINCR might aggravated glioma cell proliferation and migration via acting as competing endogenous RNA (ceRNA), indicating prospective novel therapeutic target for glioma.

Wnt-regulating microRNAs role in gastric cancer malignancy

Gastric cancer (GC) is responsible for high morbidity and mortality worldwide. This cancer claims fifth place among other cancers. There are a number of factors associated with GC development such as alcohol consumption and tobacco smoking. It seems that genetic factors play significant role in GC malignancy and progression. MicroRNAs (miRs) are short non-coding RNA molecules with negative impact on the expression of target genes. A variety of studies have elucidated the potential role of miRs in GC growth. Investigation of molecular pathways has revealed that miRs function as upstream modulators of Wnt signaling pathway. This signaling pathway involves in important biological processes such as cell proliferation and differentiation, and its dysregulation is associated with GC invasion. At the present review, we demonstrate that how miRs regulate Wnt signaling pathway in GC malignancy.

MicroRNA dysregulation interplay with childhood abdominal tumors

Abdominal tumors (AT) in children account for approximately 17% of all pediatric solid tumor cases, and frequently exhibit embryonal histological features that differentiate them from adult cancers. Current molecular approaches have greatly improved the understanding of the distinctive pathology of each tumor type and enabled the characterization of novel tumor biomarkers. As seen in abdominal adult tumors, microRNAs (miRNAs) have been increasingly implicated in either the initiation or progression of childhood cancer. Moreover, besides predicting patient prognosis, they represent valuable diagnostic tools that may also assist the surveillance of tumor behavior and treatment response, as well as the identification of the primary metastatic sites. Thus, the present study was undertaken to compile up-to-date information regarding the role of dysregulated miRNAs in the most common histological variants of AT, including neuroblastoma, nephroblastoma, hepatoblastoma, hepatocarcinoma, and adrenal tumors. Additionally, the clinical implications of dysregulated miRNAs as potential diagnostic tools or indicators of prognosis were evaluated.

Effect of CELSR3 on the Cell Cycle and Apoptosis of Hepatocellular Carcinoma Cells

Cadherin EGF LAG seven-pass G-type receptor 3 (CELSR3) has been reported in cancers but its role and potential molecular mechanism in hepatocellular carcinoma (HCC) is unclear. Therefore, we aimed to investigate the clinical value and molecular mechanism of CELSR3 in HCC using an in vitro experiment, a meta-analysis and bioinformatics. The in vitro experiment determined the promoting effect of CELSR3 in the proliferation, invasion, and migration of HCC cells. CELSR3 knockout causes S-phage arrest in HCC cells. CELSR3 can also inhibit the apoptosis of HCC cells. The expression of the CELSR3 gene and protein was significantly elevated in HCC. Elevated CELSR3 was correlated to the bigger tumor size, higher pathological stage, and the worse overall survival of HCC. Methylation analysis revealed that the hypomethylation of CELSR3 regulated by DNMT1, DNMT3A, and DNMT3B may be the underlying mechanism of upregulated CELSR3. Biological enrichment analysis uncovered that the cell cycle, DNA replication, and PI3K-Akt signaling pathways were important pathways regulated by CELSR3 and its co-expressed genes in HCC. Taken together, upregulated CELSR3 is an important regulator in the progression and prognosis of HCC. The hypomethylation of CELSR3 and its regulation in the cell cycle may be the potential molecular mechanism in HCC.

MicroRNA-876-5p represses the cell proliferation and invasion of colorectal cancer through suppressing YAP signalling via targeting RASAL2

Aberrant expression of microRNA-876-5p (miR-876-5p) is implicated in the progression of multiple human cancers. However, the potential role of miR-876-5p in colorectal cancer remains poorly understood. The purpose of the current study was to investigate the potential role of miR-876-5p in colorectal cancer. miR-876-5p expression was significantly downregulated in colorectal cancer tissues and cell lines compared with normal controls. Gain-of-function assays revealed that miR-876-5p overexpression effectively repressed the malignant behaviours of colorectal cancer cells, including cell proliferation, colony formation, and invasion. Bioinformatics analysis predicted that RAS protein activator like 2 (RASAL2), a potential oncogene for colorectal cancer, is a putative miR-876-5p target gene. A luciferase reporter assay confirmed that miR-876-5p directly binds to the 3'-untranslated region (UTR) of RASAL2. Furthermore, both RASAL2 messenger RNA (mRNA) and protein expression were negatively modulated by miR-876-5p in colorectal cancer cells. Notably, there was an inverse correlation between miR-876-5p and RASAL2 expression in colorectal cancer tissue specimens. Moreover, miR-876-5p was involved in regulating the activation of Yes-associated protein (YAP) signalling through inhibiting RASAL2. However, the miR-876-5p-mediated antitumour effect on colorectal cancer cells was partially reversed by restoring RASAL2 expression. Notably, miR-876-5p upregulation impeded the tumour growth of colorectal cancer cells in vivo in nude mice. Overall, these results demonstrated that miR-876-5p exerts an antitumour function in colorectal cancer by targeting RASAL2 to suppress YAP signalling activation. These findings highlight the importance of the miR-876-5p/RASAL2/YAP axis in colorectal cancer progression and suggest that miR-876-5p is a potential therapeutic target for treating colorectal cancer.

FBXL19-AS1 promotes cell proliferation and inhibits cell apoptosis via miR-876-5p/FOXM1 axis in breast cancer

As the most common cancer and one of the leading causes of cancer-associated mortality, breast cancer continues to need more key molecules to regulate its progression. F-box and leucine-rich repeat protein 19 antisense RNA 1 (known as FBXL19-AS1) is a long non-coding RNA (lncRNA) which has been reported as an oncogene in several types of human cancers. However, the specific downstream targets of FBXL19-AS1 remain unknown. In this study, we set out to find more reliable downstream molecules of FBXL19-AS1 in breast cancer. FBXL19-AS1 was expressed at a high level in breast cancer cells. Loss-of-function experiments revealed that silencing FBXL19-AS1 could impair cell proliferation and induce cell apoptosis in breast cancer. In addition, the location of FBXL19-AS1 in the cytoplasm was detected by fluorescent in situ hybridization assay, while FBXL19-AS1 regulated the expression of Forkhead box M1 (FOXM1) by directly absorbing miR-876-5p. Through rescue assays, it was observed that FOXM1 overexpression recovered the inhibited tumor growth caused by FBXL19-AS1 downregulation. We affirmed the function of FBXL19-AS1 in breast cancer and described the mechanism of the FBXL19-AS1/miR-876-5p/FOXM1 axis. The current work presents the molecular mechanism which underlies FBXL19-AS1 in breast cancer and suggests a comprehensive, feasible FBXL19-AS1-mediated therapeutic approach for treating breast cancer.

Positive feedback loop of lncRNA HOXC-AS2/miR-876-5p/ZEB1 to regulate EMT in glioma

Purpose

Growing evidence has valued the diagnostic and therapeutic ability of long non-coding RNAs (lncRNAs) in various human tumors including glioma. Here, we investigated the biological function and potential mechanism of a novel cancer-related lncRNA, HOXC-AS2, in glioma.

Materials and methods

The expression of lncHOXC-AS2 was detected using qRT-PCR in glioma cells and tissues. A series of in vitro studies were performed to analyze the biological function of lncHOXC-AS2. Dual-luciferase reporter, RIP was used to determine the relation between lncHOXC-AS2, miR-876-5p and ZEB1. CHIP assay was performed to investigate the transcriptional regulation of HOXC-AS2.

Results

We found HOXC-AS2 was upregulated in glioma cells and tissues. Depletion of HOXC-AS2 was associated with the inhibition of migration, invasion and EMT process in glioma cells. Mechanism, HOXC-AS2 can sponge miR-876-5p to affect ZEB1 expression. Meanwhile, ZEB1 can bind promoter region of HOXC-AS2 and regulate HOXC-AS2 at transcriptional level.

Conclusion

Our results conclude that HOXC-AS2/miR-876-5p/ZEB1 constitutes a positive feedback loop to regulate EMT in GBM, providing a potential therapeutic target for glioma.

Long non-coding RNA transcribed from pseudogene PPIAP43 is associated with radiation sensitivity of small cell lung cancer cells

Small cell lung cancer (SCLC) is a highly lethal disease. Although radiation therapy is effective for the majority of patients with SCLC, patient sensitivity to radiation varies. The lack of biomarkers impedes advances in targeting radiation-sensitive patients. In this study, the changes in transcription patterns of SCLC cell lines were evaluated with or without 2 Gy gamma radiation. The results demonstrated that peptidyl-prolyl cis-trans isomerase A pseudogene 43 (PPIAP43) transcription was increased 2-fold in cells irradiated with 2 Gy gamma radiation compared with unirradiated cells in pre-reported radio-sensitive sensitive cell lines H69, H128, H146, H209 and H187. These cells shared 259 upregulated and 96 downregulated RNA transcripts following radiation. Pre-reported less sensitive cell lines H526, D53, D114 and D153 in which PPIAP43 was not upregulated 2-fold following irradiation with 2 Gy gamma radiation compared with unirradiated cells, shared 3 upregulated and 9 downregulated RNA transcripts. The RNA transcript of PPIAP43 was aligned with the mRNA of peptidyl-prolyl cis-trans isomerase A (PPIA) at 2 sections (3,732 to 3,917 and 5,327 to 5,657 of the PPIA gene) and the sequences were shown to be 96 and 94% similar, respectively. Therefore, PPIAP43 may act as a sponge for microRNAs which bind with the RNA of PPIA. Therefore, PPIAP43 RNA transcription may serve as a potential biomarker of radio-sensitivity of SCLC.

MicroRNA-30a-3p inhibits the progression of lung cancer via the PI3K/AKT by targeting DNA methyltransferase 3a

Background

MicroRNAs (miRNAs) are small non-coding RNAs, involved in pathological and physiological processes via regulating target genes expression. Abnormally expressed miR-30a-3p has been verified in several tumors, such as liver cancer, esophageal cancer and lung cancer. It was reported that DNA methylation plays a critical role in the tumorigenesis of lung cancer through regulated tumor suppressor genes silencing. Nevertheless, the potential mechanism of miR-30a-3p in restoring abnormal DNA methylation patterns is still unclear in lung cancer. Therefore, because the miR-30a-3p is complementary to the 3ʹ-untranslated regions (3ʹ-UTR) of DNA methyltransferase 3A (DNMT3A), we investigated whether miRNA-30a-3p could target DNMT3a to regulate the progression of lung cancer cell.

Methods

qRT-PCR was used to evaluate miR-30a-3p and DNMT3a mRNA expression levels in A549 lung cancer cells and normal cell line BEAS-2B. MiR-30a-3p expression plasmid was transferred into A549 cells. The target of miR-30a-3p was detected by luciferase reporter assay. Western blot was used to measure related protein expression levels. MTT assay was used to measure the proliferation of cells in each group. The cycle and apoptosis of cells were detected by flow cytometry.

Results

We found down-regulation of miR-30a-3p mRNA expression and up-regulation of DNMT3a mRNA expression in A549 cells. Overexpression of miR-30a-3p downregulates DNMT3a or blocked DNMT3a by interference vector, significantly inhibited the proliferation and G1/S transition in A549 cells via regulating p38 MAPK pathway, and induced the apoptosis in A549 cells via regulating Bcl-2/Bax protein levels. Furthermore, we observed the opposite phenomenon in A549 cells transfected with both miR-30a-3p and DNMT3a vector.

Conclusion

Our data show that miR-30a-3p suppressed the progression of lung cancer via regulating p38 MAPK pathway by targeting DNMT3A in A549 cells, indicating that miR-30a-3p might be a novel potential therapeutic strategy in the treatment of lung cancer.

Overexpression of miR-450 affects the biological behavior of HepG2 cells by targeting DNMT3a

Purpose

This study was designed to explore the regulation mechanism of miR-450 in the development of hepatocarcinoma, and the effects of overexpression of miR-450 on biological behaviors such as proliferation, migration, and invasion of hepatoma cells.

Methods

HepG2 cells were divided into miR-450 mimics group, miR-450 inhibitor group, miR-450 mimics NC group, miR-450 inhibitor NC group, and blank group. MTT assay was served to measure cell proliferation, and Transwell assay was used to test cell migration and invasion. Additionally, cell cycle was detected by flow cytometry and apoptosis was examined with AnnexinV-PI double staining. After the target gene of miR-450 was predicted by bioinformatics software, Western blot and dual luciferase reporter gene experiment were applied to verify the relationship between miR-450 and target gene.

Results

The MTT and Transwell assay indicated that overexpression of miR-450 inhibited the proliferation, invasion, and migration of HepG2 cells. The flow cytometry analysis showed that overexpression of miR-450 arrested the cell cycle in the G1 phase. Meanwhile, Annexin V-PI double staining assay revealed that overexpression of miR-450 promoted apoptosis of HepG2 cells. However, silencing miR-450 in HepG2 cells promoted proliferation and invasion, and reduced apoptosis. Moreover, we found that DNMT3a was the target gene of miR-450.

Conclusions

miR-450 could inhibit proliferation, invasion, and migration via regulating DNMT3a in hepatocarcinoma cells, which provided a theoretical basis for the treatment of liver cancer.

MiR-876-5p regulates gastric cancer cell proliferation, apoptosis and migration through targeting WNT5A and MITF

MicroRNAs (miRNAs) are reported to play critical roles in various cancers. Recently, mounting miRNAs are found to exert oncogenic or tumor inhibitory role in gastric cancer (GC), however, their potential molecular mechanism in GC remains ill-defined. Currently, we aimed to elucidate the functional and mechanistic impacts of a novel miRNA on GC cellular process. The significant down-regulation of miR-876-5p in GC cells attracted our attention. In function, we performed gain-of-function assays and found that miR-876-5p overexpression repressed proliferative, anti-apoptotic and migratory abilities and epithelial-mesenchymal transition (EMT) of GC cells. By applying bioinformatics prediction and mechanism experiments, we verified that miR-876-5p could double-bind to the 3' untranslated regions (3'UTRs) of Wnt family member 5A (WNT5A) and melanogenesis associated transcription factor (MITF), thus regulating their mRNA and protein levels. Both WNT5A and MITF were highly expressed in GC cells. Additionally, we conducted loss-of-function assays and confirmed the oncogenic roles of WNT5A and MITF in GC. Finally, rescue assay uncovered a fact that miR-876-5p suppressed GC cell viability and migration, but induced cell apoptosis via targeting WNT5A and MITF. Taken together, we might offer a valuable evidence for miR-876-5p role in GC development.

miR-876-5p suppresses breast cancer progression through targeting TFAP2A

MicroRNAs (miRNAs) are widely expressed in human cells and closely associated with various types of cancer, including breast cancer. miR-876-5p has been indicated to participate in the tumorigenesis of certain types of cancer, such as hepatocellular carcinoma. Nevertheless, the roles of miR-876-5p in breast cancer remain unclear. In the present study, it was revealed that miR-876-5p expression levels were decreased in breast cancer cells compared with a normal cell line. miR-876-5p ectopic expression suppressed breast cancer cell proliferation and arrested progression of the cell cycle. In addition, miR-876-5p suppressed breast cancer cell migration and invasion. miR-876-5p was demonstrated to directly target transcription factor AP-2-α (TFAP2A) in breast cancer cells, and restoration of TFAP2A rescinded the suppressive role of miR-876-5p. In summary, the results from the present study provide evidence that miR-876-5p suppresses breast cancer progression by regulating cell proliferation, migration and invasion in a TFAP2A-dependent manner.

MicroRNA-876 is sponged by long noncoding RNA LINC00707 and directly targets metadherin to inhibit breast cancer malignancy

Background: MicroRNA-876-5p (miR-876) dysregulation contributes to the aggressiveness of various types of human cancer. This study was aimed at measuring miR-876 expression in breast cancer, determining the specific roles of miR-876 in the progression of breast cancer and understanding the corresponding molecular mechanisms.

Materials and methods: miR-876 expression in breast cancer tissues and cell lines was quantified via RT-qPCR. The effect of miR-876 upregulation on the malignant phenotype of breast cancer cells was investigated using CCK-8 assays, flow cytometry, Transwell migration and invasion assays and tumor xenograft experiments. The mechanisms underlying the tumor-suppressive action of miR-876 in breast cancer cells were explored using bioinformatic analysis, luciferase reporter assays, RT-qPCR and Western blot analysis.

Results: miR-876 was found to be underexpressed in breast cancer tissues and cell lines. Decreased miR-876 expression notably correlated with lymphatic invasion metastasis, TNM stage and differentiation grade. Overall survival was lower among patients with breast cancer and low miR-876 expression than in patients with high miR-876 expression. Restoration of miR-876 expression decreased breast cancer cell proliferation, migration and invasion in vitro and restricted tumor growth in vivo as well as increased cell apoptosis. Metadherin (MTDH) was identified as a novel target of miR-876 in breast cancer cells. Furthermore, long intergenic nonprotein-coding RNA 707 (LINC00707) acted as a molecular sponge for miR-876, thereby regulating MTDH expression in breast cancer. Finally, silencing miR-876 expression attenuated the influence of a LINC00707 knockdown on the malignancy of breast cancer cells.

Conclusion: This study, thus, revealed the vital functions of the LINC00707–miR-876–MTDH pathway in breast cancer and provided attractive targets and markers for its treatment.

FOXM1-Mediated LINC-ROR Regulates the Proliferation and Sensitivity to Sorafenib in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-associated death worldwide. Indeed, despite the benefit of sorafenib in the treatment of some patients with HCC, the majority of these patients have a poor response to or intolerance of sorafenib, resulting in further tumor progression. Exploring the mechanisms underlying sorafenib resistance is essential to the treatment of HCC. Long noncoding RNAs (lncRNAs) are known as participants in tumorigenesis. In this study, we identified that long intergenic non-protein coding RNA, regulator of reprogramming (LINC-ROR), was upregulated in HCC cell lines, which was transcriptionally activated by FOXM1. Furthermore, the sponging of miR-876-5p by LINC-ROR released FOXM1, thereby forming a positive-feedback loop. Additionally, we demonstrated that upregulation of both FOXM1 and LINC-ROR impaired the sensitivity to sorafenib in HCC cells. The role of this feedback loop was demonstrated by rescue assays. These results revealed a novel molecular feedback loop between LINC-ROR and FOXM1 and elucidated their functions in sorafenib sensitivity of HCC cell lines.

MicroRNA-876-5p inhibits cell proliferation, migration and invasion by targeting c-Met in osteosarcoma

Recently, aberrant expression of miR‐876‐5p has been reported to participate in the progression of several human cancers. However, the expression and function of miR‐876‐5p in osteosarcoma (OS) are still unknown. Here, we found that the expression of miR‐876‐5p was significantly down‐regulated in OS tissues compared to para‐cancerous tissues. Clinical association analysis indicated that underexpression of miR‐876‐5p was positively correlated with advanced clinical stage and poor differentiation. More importantly, OS patients with low miR‐876‐5p level had a significant shorter overall survival compared to miR‐876‐5p high‐expressing patients. In addition, gain‐ and loss‐of‐function experiments demonstrated that miR‐876‐5p restoration suppressed whereas miR‐876‐5p knockdown promoted cell proliferation, migration and invasion in both U2OS and MG63 cells. In vivo studies revealed that miR‐876‐5p overexpression inhibited tumour growth of OS in mice. Mechanistically, miR‐876‐5p reduced c‐Met abundance in OS cells and inversely correlated c‐Met expression in OS tissues. Herein, c‐Met was recognized as a direct target of miR‐876‐5p using luciferase reporter assay. Notably, c‐Met restoration rescued miR‐876‐5p attenuated the proliferation, migration and invasion of OS cells. In conclusion, these findings indicate that miR‐876‐5p may be used as a potential therapeutic target and promising biomarker for the diagnosis and prognosis of OS.

MiR-876-5p modulates head and neck squamous cell carcinoma metastasis and invasion by targeting vimentin

BACKGROUND

Local or distant metastasis remains the main course of death in head and neck squamous cell carcinoma (HNSCC) patients. MicroRNAs (miRNAs) have been implicated in metastasis of HNSCC, but the mechanisms of their action are mainly undocumented. Through public head and neck cancer miRNA expression datasets, we found that miR-876-5p was a novel potential tumor suppressor targeting HNSCC metastasis.

METHODS

Clinical significance and mechanism of miR-876-5P was systematically analyzed in HNSCC. Quantitative RT-PCR was used to evaluate miR-876-5p levels in HNSCC cell lines and in 20 pairs of HNSCC with associated regional nodal metastases and HNSCC without metastatic primary tumors. Scratch and invasion assays were evaluated to determine the role of miR-876-5p in the regulation of HNSCC cell migration and invasion, respectively. Western blotting was used to investigate the mechanism by which miR-876-5p suppresses HNSCC cell invasion and migration. Luciferase assays were performed to assess miR-876-5p binding to the vimentin gene. The animal model was used to support the in vitro experimental findings.

RESULTS

MiR-876-5p mimics inhibited HNSCC cell migration and invasion. Vimentin protein and mRNA levels were decreased in the miR-876-5p mimics group but increased in the miR-876-5p inhibitors group, which demonstrated that miR-876-5p inhibits vimentin expression in HNSCC cells. By directly targeting the vimentin 3'-UTR, we used dual-luciferase reporter assays to verify that vimentin is a functional downstream target of miR-876-5p. Importantly, increased vimentin expression promoted cell migration and invasion, and co-transfection with miR-876-5p mimics and vimentin restored cell aggressiveness to the original level. Moreover, miR-876-5p overexpression significantly downregulated vimentin expression level and inhibited the distal metastasis of HNSCC cells in vivo.

CONCLUSIONS

miR-876-5p, which functions as a tumor suppressor in HNSCC, inhibits metastasis by targeting vimentin and provides a novel therapeutic target for HNSCC treatment.