Diagnostic value and cognitive regulatory roles of long non-coding RNA UCA1 in Alzheimer's disease

BACKGROUND

To explore the diagnostic role and potential mechanism of serum lncRNA UCA1 in Alzheimer's disease (AD).

METHODS

UCA1 concentration was determined using quantitative RT-PCR. The receiver operating characteristic curve was plotted to assess the diagnostic value. Cell viability and apoptotic capacity were assessed by cell counting kit-8 (CCK-8) and flow cytometry. Water maze experiments were used to test cognitive function in mice. The target genes of UCA1 were identified with a dual luciferase reporter assay. Functional and pathway analysis of miR-342-3p target genes was determined using enrichment analysis.

RESULTS

The concentration of UCA1 was elevated in the AD group and represented a diagnostic possibility of AD. The silenced UCA1 reduced the roles of Aβ on viability and apoptosis of SH⁃SY5Y cells by sponging miR-342-3p. The impaired cognitive impairment was partly recovered by the knockdown of the UCA1/miR-342-3p axis. Potential targets of miR-342-3p were enriched in function and pathways related to AD progression.

CONCLUSION

The UCA1/miR-342-3p axis contributed to the occurrence of AD by regulating cognitive ability.

Differential gene expression and miRNA regulatory network in coronary slow flow

Coronary slow flow (CSF) is characterized by slow progression of coronary angiography without epicardial stenosis. The aim of this study was to explore the potential biomarkers and regulatory mechanism for CSF. Peripheral blood mononuclear cells from 3 cases of CSF and 3 healthy controls were collected for high-throughput sequencing of mRNA and miRNA, respectively. The differentially expressed mRNAs (DE-mRNAs) and miRNAs (DE-miRNAs) was identified. A total of 117 DE-mRNAs and 32 DE-miRNAs were obtained and they were mainly enriched in immune and inflammatory responses. Twenty-six DE-mRNAs were the predicted target genes for miRNAs by RAID, and then the regulatory network of 15 miRNAs were constructed. In addition, through the PPI network, we identified the three genes (FPR1, FPR2 and CXCR4) with larger degrees as hub genes. Among them, FPR1 was regulated by hsa-miR-342-3p, hsa-let-7c-5p and hsa-miR-197-3p and participated in the immune response. Finally, we validated the differential expression of hub genes and key miRNAs between 20 CSF and 20 control. Moreover, we found that miR-342-3p has a targeted regulatory relationship with FPR1, and their expression is negatively correlated. Then we established a hypoxia/reoxygenation (H/R) HUVEC model and detected FPR1, cell proliferation and apoptosis. Transfection with miR-342-3p mimics can significantly promote the proliferation of HUVEC under H/R conditions. FPR1 were associated with CSF as a biomarker and may be regulated by miR-342-3p potential biomarkers.

LINC02086 inhibits ferroptosis and promotes malignant phenotypes of pancreatic cancer via miR-342-3p/CA9 axis

Long noncoding RNAs (lncRNAs) play important roles in modulating the tumorigenesis and progression of malignant tumors. LINC02086 is a newly identified oncogene associated with tumorigenesis, but its role in pancreatic cancer (PC) has not been fully elucidated. In this study we examined the expression levels of LINC02086, miR-342-3p, and CA9 in PC. The relationship of ferroptosis with these factors was analyzed by detecting the expression levels of Fe2+, reactive oxygen species (ROS), and ferroptosis marker proteins. The expression of these genes was altered to observe their effects on cell proliferation, migration, and invasion ability. Bioinformatics was used to predict target genes, and the binding relationship was verified luciferase reporter assay. Finally, the function of LINC02086 was evaluated in vivo. The findings suggest that LINC02086 is highly expressed in PC tissues and cell lines and is correlated with a poor prognosis. In vitro experiments demonstrated that LINC02086 knockdown promoted ferroptosis in PC cells to suppress their malignant phenotype. LINC02086 acts as a competitive endogenous RNA that adsorbed miR-342-3p. miR-342-3p hinders the malignant progression of PC by promoting ferroptosis. In addition, miR-342-3p targets CA9 and affects its function. Further mechanistic studies revealed that LINC02086 inhibits ferroptosis and promotes PC progression by acting as a sponge for miR-342-3p to upregulate CA9 expression. In vivo experiments further confirmed this mechanism. Taken together, LINC02086 upregulates CA9 expression by competitively binding with miR-342-3p, thereby inhibiting ferroptosis in PC cells and promoting their malignant phenotype. The results of our study provide new insights into how LINC02086 contributes to the progression of PC.

LINC00624 affects hepatocellular carcinoma proliferation and apoptosis through the miR-342-3p/DNAJC5 axis

LINC00624 is a long noncoding RNA (lncRNA) which was seldom investigated before. The goal of our study is to clarify the expression and underlying network of LINC00624 in hepatocellular carcinoma (HCC). Here, both HCC and normal living cell lines were employed. Real-time quantitative PCR and western blot were used to determine the pattern of genes and proteins. Colony formation, flow cytometry and western blot tests were used to determine cell proliferation and apoptosis, respectively. Dual luciferase was used to verify molecule-molecule interactions. LINC00624 expression was increased in HCC cell lines and miR-342-3p was decreased. Elimination of LINC00624 increased proliferation while decreasing cell apoptosis. LINC00624 acted as a molecular sponge for miR-342-3p, hence facilitating DNAJC5 expression. Functional tests demonstrated that miR-342-3p suppression could reverse the effect of LINC00624 silence and overexpression of DNAJC5 significantly mitigated the biological consequences of miR-342-3p. These finding demonstrated that LINC00624 aggravated HCC progression by modulating proliferation and apoptosis via targeting miR-342-3p/DNAJC5 axis. These data support that inhibition of LINC00624 may a potential treatment strategies of HCC.

Puerarin alleviates chronic renal failure-induced pyroptosis in renal tubular epithelial cells by targeting miR-342-3p/TGF-β/SMAD axis

BACKGROUND

Chronic renal failure (CRF) is the result of kidney damage. Puerarin is a flavonoid with specific nephroprotective effect, but its effect on CRF needs further research. This study explored the effect of puerarin on CRF and the potential molecular mechanism.

METHODS

Adenine was used to establish an in vivo CRF model in rats, and rats were intragastrically administered with puerarin at a dose of 400 mg/kg body weight once a day from day 1 to day 28. Hematoxylin and eosin (HE) and Masson staining were used to observe the morphology and fibrosis of kidney tissue. Lipopolysaccharide (LPS) (400 ng/mL)/H2O2 (200 µM) was applied to human kidney 2 (HK-2) cells to construct an in vitro CRF model. Enzyme-linked immunosorbent assay (ELISA) was performed to validate interleukin (IL)-1β and IL-18 levels. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was performed to detect microRNA (miR)-342-3p levels. Transforming growth factor beta (TGF-β)1, SMAD2, SMAD3, and pyroptosis marker proteins were detected by Western blot. The interaction between miR-342-3p and TGF-β/SMAD was determined by a dual-luciferase reporter gene assay. Cell Counting Kit-8 (CCK-8) assay was utilized to determine cell viability.

RESULTS

In the CRF model, puerarin alleviated renal injury and fibrosis and reduced creatinine (Cr) and blood urea nitrogen (BUN) levels. At the same time, miR-342-3p was downregulated, while the TGF-β/SMAD axis was activated and levels of IL-1β and IL-18 were increased. After treatment of CRF rats with puerarin, the expression level of miR-342-3p was increased, the TGF-β/SMAD axis was inhibited, and the secretion of IL-1β and IL-18 was decreased. MiR-342-3p directly bound to and negatively regulated the expression of TGF-β1, SMAD2, and SMAD3. In the in vitro CRF model, miR-342-3p inhibited HK-2 cell pyroptosis by inhibiting the TGF-β/SMAD axis.

CONCLUSION

Puerarin reduced renal injury and pyroptosis in CRF rats by targeting the miR-342-3p/TGF-β/SMAD axis.

Serum miR-342-3p Acts as a Biomarker for Systemic Lupus Erythematosus and Participates in the Disease Progression

Purpose

The aim of this study was to investigate the diagnostic ability and prognostic value of miR-342-3p in SLE patients by detecting the expression level of serum miR-342-3p in SLE patients.

Patients and Methods

The expression level of serum miR-342-3p in all subjects was determined by qRT-PCR technology, and the correlation of miR-342-3p with SLEDAI scores was evaluated using Spearman correlation coefficient. The diagnostic value of miR-342-3p in SLE was assessed using ROC curve. The prognostic value of miR-342-3p in SLE patients was analyzed by Kaplan-Meier survival curve and multivariate COX regression.

Results

The qRT-PCR results showed that the expression level of serum miR-342-3p in SLE patients was significantly lower than that in healthy controls (P < 0.001). Serum miR-342-3p expression level was negatively correlated with SLEDAI scores (r = - 0.810, P < 0.001). The ROC curve suggested that serum miR-342-3p expression level was discriminative between SLE patients and healthy controls. Survival analysis results indicated that SLE patients with low serum miR-342-3p expression had a higher probability of poor prognosis of SLE (Log rank P = 0.003).

Conclusion

The expression level of serum miR-342-3p was valuable in the diagnosis of SLE. Meanwhile, the low expression level of serum miR-342-3p was associated with the poor prognosis of SLE.

Circ_0006220 Contributes to NSCLC Progression through miR-342-3p/GOT2 Axis

PURPOSE

Dysregulated circular RNAs (circRNAs) have shown crucial modulatory functions in tumorigenesis, containing non-small cell lung cancer (NSCLC). The purpose of this study was to explore the biological functions and regulatory theory of circ_0006220 in NSCLC.

METHODS

Reverse transcription-quantitative polymerase chain reaction and Western blot assay were conducted to measure RNA and protein expression, respectively. A total of 73 cases of NSCLC tumor samples were collected for expression analysis, and A-549 and NCI-H1299 cell lines were used for functional experiments. Cell proliferation was assessed by cell counting kit-8 assay, colony formation assay, 5-ethynyl-2'-deoxyuridine assay, and flow cytometry. Cell apoptosis, motility, and angiogenesis ability were analyzed by flow cytometry, transwell assays, and capillary-like network formation assay. Dual-luciferase reporter assay and RNA immunoprecipitation assay were conducted to verify the target relationships.

RESULTS

Circ_0006220 was highly expressed in NSCLC tissues and cell lines. Circ_0006220 silencing inhibited the proliferation, migration, invasion, and angiogenesis but induced the apoptosis of NSCLC cells. Circ_0006220 acted as a microRNA-342-3p (miR-342-3p) sponge, and circ_0006220 knockdown-induced changes on the phenotypes of NSCLC cells were largely overturned by the knockdown of miR-342-3p. miR-342-3p interacted with the 3' untranslated region of glutamic-oxaloacetic transaminase 2 (GOT2), and GOT2 overexpression largely diminished miR-342-3p overexpression-mediated influences in NSCLC cells. Circ_0006220 could up-regulate GOT2 expression by sponging miR-342-3p.

CONCLUSION

Circ_0006220 promoted the malignant behaviors of NSCLC cells through mediating the miR-342-3p/GOT2 regulation cascade.

Downregulatory effect of miR-342-3p on epileptogenesis in the PTZ-kindling model

BACKGROUND

Epileptogenesis is a process that results in neurons firing abnormally, causing seizures. Increasing evidence has shown that miRNAs expressed in the epileptic hippocampus are involved in epileptogenesis. We demonstrated the expression changes of miRNAs that may be effective in epileptogenesis in silico analysis in the kindling model created with Pentylenetetrazole (PTZ). Thus, we aimed to identify the target genes responsible for epileptogenesis.

METHODS AND RESULTS

Fifteen male Wistar-albino rats (200-230 g) were randomly divided into two groups control (n = 6) and PTZ (n = 9). The control group received 0.5 ml saline, and the PTZ group (35 mg/kg i.p.) intraperitoneally (i.p.) (11 times, every other day) to induce tonic-clonic seizures. Seizures were observed and scored 30 min after PTZ injection. After the last dose of PTZ (75 mg/kg) administration, the hippocampus tissues of the rats were removed by anesthesia. Analysis of miRNAs was performed with the Affymetrix gene chip miRNA sequence (728 miRNA) and confirmed by the Real-Time Polymerase Chain Reaction (Real-Time PCR) method (29 miRNAs). We evaluated the expression change of the target gene of miRNA, whose expression change was detected using in silico analysis, by q-RT PCR. Eight miRNAs with changes in expression were detected. Of these miRNAs, miR-342-p was downregulated in the PTZ group and was statistically significant (p < 0.005). Ultimately, we determined that the target gene of miR-342-p is a metabotropic glutamate receptor 2 (GRM2) and that GRM2 expression is upregulated.

CONCLUSIONS

Downregulation of miR-342-3p in the PTZ kindling model may result in the upregulation of GRM2.

[Expression of miR-342-3p in rheumatoid arthritis patients and its effect on synovial fibroblast inflammation and migration]

OBJECTIVE

To investigate the expression level of miR-342-3p in peripheral blood mononuclear cells (PBMCs) of patients with rheumatoid arthritis (RA) and its effect on inflammatory response and migration of synovial fibroblasts in RA (RA-FLS).

METHODS

PBMCs were collected from 30 healthy individuals and 50 RA patients for detecting the expression of miR-342-3p, and its correlation with the clinical indicators RF, ESR, anti-CCP, hs-CRP, C3, DAS-28, SAS, and SDS was analyzed. In RA-FLS cultures, the effect of transfection of miR-342-3p mimics and inhibitor on TNF-α-induced inflammatory response of the cells was evaluated by detecting the expressions of IL-1β, IL-6, IL-10, and TNF-α using ELISA. CCK8 assay and Transwell assay were used for detecting the changes in cell viability and migration ability of the synovial cells.

RESULTS

In RA patients, the expression level of miR-342-3p was significantly lowered in the PBMCs (P < 0.05) with an area under the ROC curve of 97.53% and showed inverse correlations with RF (r=-0.321), ESR(r=-0.284), anti-CCP (r=-0.355), hs-CRP (r=-0.320), C3 (r=-0.294), DAS-28 (r=-0.395), SAS (r=-0.366), and SDS (r=-0.397) (all P < 0.05); a low expression of miR-342-3p was strongly associated with elevated levels of anti-CCP, DAS-28, SDS, and SAS (all with a rule support greater than 85%, confidence greater than 88%, and lift greater than 1). In cultured RA-FLS, TNF-α stimulation significantly increased the cell viability (P < 0.05), upregulated the expressions of IL-1β, IL-6, and TNF-α, and lowered the expression of IL-10 (P < 0.05). These changes were significantly suppressed by transfection of the cells with miR-342-3p mimics (P < 0.05) but enhanced by transfection with miR-342-3p inhibitor (P < 0.05).

CONCLUSION

The expression of miR-342-3p is decreased in the PBMCs of RA patients. A lowered expression of miR-342-3p contributes to the pathogenesis of RA by promoting inflammatory responses and migration of RA-FLS.

SNHG20 promotes the development of laryngeal squamous cell carcinoma via miR-342-3p/MTDH axis

Long noncoding RNAs (lncRNAs) are important players in laryngeal squamous cell carcinoma (LSCC). However, the function of the long noncoding RNA small nucleolar RNA host gene 20 (SNHG20) in LSCC is hardly known. We therefore analyzed the role of this lncRNA in LSCC. Our data showed that SNHG20 was significantly overexpressed in LSCC cell lines and human LSCC tissue. SNHG20 significantly promoted cell proliferation, migration and invasion of LSCC cells. The actions of SNHG20 are likely mediated by miR-342-3p expression, which results in increased expression of MTDH. Finally, the results of in vivo models confirmed that SNHG20 promotes LSCC progression through modulating miR-342-3p and MTDH expression. Taken together, our study demonstrates that SNHG20/miR-342-3p/MTDH axis participates in LSCC progression.

Mesenchymal stem cell-derived exosome mir-342-3p inhibits metastasis and chemo-resistance of breast cancer through regulating ID4

BACKGROUND

The mesenchymal stem cell-derived exosome (MSCs-exo) carrying microRNAs have been proved to regulate tumor biological activities. Clarifying molecular mechanism and identifying predictive microRNAs will be of great value in anti-tumor therapy improvement.

OBJECTIVE

We aimed to investigate the regulatory role of microRNA-342-3p (miR-342-3p) in MSCs-exo on breast cancer.

METHODS

Breast cancer tissues and cell lines were used to evaluate miR-342-3p expression in patients with or without lymph node/distal organ metastasis. The impact of MSCs-exo expression on tumor cell chemo-resistance and invasion/migration was measured. Dual-luciferase reporter gene assay was applied to identify binding site. Inhibitor of differentiation 4 (ID4) siRNA and miR-342-3p inhibitor transfection was conducted to further explore the miR-342-3p/ID4 axis on chemo-resistance and metastasis of breast cancer cells.

RESULTS

Breast cancer cells revealed significantly lower level of miR-342-3p in patients with metastatic diseases. miR-342-3p suppressed invasive and chemo-resistant behavior of breast cancer tumor cells. Binding site between miR-342-3p and ID4 was proved. ID4 could reverse the influence of miR-342-3p on chemo-resistance. The tumor inhibition effect of IDA siRNA in vivo was also identified.

CONCLUSIONS

This study demonstrated that miR-342-3p acted as potential tumor suppressor by inhibiting metastasis and chemo-resistance of breast cancer cells through targeting ID4. This study might provide potential therapy targets for the treatment of breast cancer.

LncRNA TP73-AS1 promotes nasopharyngeal carcinoma progression through targeting miR-342-3p and M2 polarization via exosomes

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a deadly cancer, mainly presenting in southeast and east Asia. Long noncoding RNAs (lncRNAs) play essential roles in cancer progression. Exosomes are critical for intercellular communication. Thus, the aim of this study was to identify the functional lncRNAs in NPC and its relevant mechanisms.

METHODS

Data from public databases were utilized to screen for functional lncRNAs in NPC. Functional and mechanical experiments were performed to determine the role of lncRNAs in NPC and its relative molecular mechanisms. Exosomes derived from NPC cells were isolated to determine their function in tumor-associated macrophages.

RESULTS

LncRNA TP73-AS1 was increased in NPC cells and tissues and was associated with a poor prognosis. TP73-AS1 overexpression promoted proliferation, colony formation, and DNA synthesis of NPC cells while TP73-AS1 knockdown showed opposite roles. TP73-AS1 could directly bind with miR-342-3p. MiR-342-3p overexpression attenuated the effect of TP73-AS1 in NPC cells. Furthermore, TP73-AS1 was transferred by exosomes to promote M2 polarization of macrophages. Lastly, exosomal TP73-AS1 enhanced the motility and tube formation of macrophages.

CONCLUSIONS

Together, this study suggests that TP73-AS1 promotes NPC progression through targeting miR-342-3p and exosome-based communication with macrophages and that TP73-AS1 might be an emerging biomarker for NPC.

Circular RNA circVAPA contributes to non-small-cell lung cancer progression via miR-342-3p-dependent regulation of ZEB2

BACKGROUND

Accumulating evidence demonstrated that circular RNAs (circRNAs) play pivotal regulatory roles in the pathology of cancers. Disclosing the roles and molecular mechanisms of circRNAs in tumorigenesis and development is essential to identify novel diagnostic and therapeutic targets. In this study, we explored the role of circVAPA in non-small-cell lung cancer (NSCLC) progression and its associated mechanism.

METHODS

The expression level of RNA was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation was assessed by MTT assay and colony-forming assay. Cell apoptosis was analyzed by flow cytometry. Cell migration and invasion were assessed by transwell assays. Dual-luciferase reporter, RNA pull-down, and RNA immunoprecipitation (RIP) assays were used to test the intermolecular interactions. The role of circVAPA was assessed in vivo. And xenograft tumor tissues were analyzed by immunohistochemistry (IHC) staining.

RESULTS

CircVAPA expression was upregulated in NSCLC tissues and cell lines, and a high level of circVAPA was associated with a poor prognosis of NSCLC patients. CircVAPA silencing suppressed the proliferation, migration, and invasion and induced the apoptosis of NSCLC cells. CircVAPA served as a molecular sponge for microRNA-342-3p (miR-342-3p). miR-342-3p interference largely reversed circVAPA knockdown-mediated anti-tumor effects in NSCLC cells. Zinc finger E-box-binding homeobox 2 (ZEB2) was a target of miR-342-3p, and miR-342-3p overexpression suppressed the malignant behaviors of NSCLC cells largely by downregulating ZEB2. CircVAPA silence repressed xenograft tumor growth in vivo, and IHC assay confirmed that circVAPA silence restrained the proliferation and metastasis but induced the apoptosis of NSCLC cells in vivo.

CONCLUSION

CircVAPA contributes to the progression of NSCLC by binding to miR-342-3p to upregulate ZEB2. CircVAPA/miR-342-3p/ZEB2 axis might be a novel potential target for NSCLC treatment.

Effects of single bouts of different endurance exercises with different intensities on microRNA biomarkers with and without blood flow restriction: a three-arm, randomized crossover trial

PURPOSE

Physical activity is associated with altered levels of circulating microRNAs (ci-miRNAs). Changes in miRNA expression have great potential to modulate biological pathways of skeletal muscle hypertrophy and metabolism. This study was designed to determine whether the profile of ci-miRNAs is altered after different approaches of endurance exercise.

METHODS

Eighteen healthy volunteers (aged 24 ± 3 years) participated this three-arm, randomized-balanced crossover study. Each arm was a single bout of treadmill-based acute endurance exercise at (1) 100% of the individual anaerobic threshold (IANS), (2) at 80% of the IANS and (3) at 80% of the IANS with blood flow restriction (BFR). Load-associated outcomes (fatigue, feeling, heart rate, and exhaustion) as well as acute effects (circulating miRNA patterns and lactate) were determined.

RESULTS

All training interventions increased the lactate concentration (LC) and heart rate (HR) (p < 0.001). The high-intensity intervention (HI) resulted in a higher LC than both lower intensity protocols (p < 0.001). The low-intensity blood flow restriction (LI-BFR) protocol led to a higher HR and higher LC than the low-intensity (LI) protocol without BFR (p = 0.037 and p = 0.003). The level of miR-142-5p and miR-197-3p were up-regulated in both interventions without BFR (p < 0.05). After LI exercise, the expression of miR-342-3p was up-regulated (p = 0.038). In LI-BFR, the level of miR-342-3p and miR-424-5p was confirmed to be up-regulated (p < 0.05). Three miRNAs and LC show a significant negative correlation (miR-99a-5p, p = 0.011, r = - 0.343/miR-199a-3p, p = 0.045, r = - 0.274/miR-125b-5p, p = 0.026, r = - 0.302). Two partial correlations (intervention partialized) showed a systematic impact of the type of exercise (LI-BFR vs. HI) (miR-99a-59: r = - 0.280/miR-199a-3p: r = - 0.293).

CONCLUSION

MiRNA expression patterns differ according to type of activity. We concluded that not only the intensity of the exercise (LC) is decisive for the release of circulating miRNAs-as essential is the type of training and the oxygen supply.

Hsa_circ_0004674 promotes osteosarcoma doxorubicin resistance by regulating the miR-342-3p/FBN1 axis

Background

The occurrence of chemoresistance is a common problem in tumor treatment. Circular RNA (circRNA) has been confirmed to be related to tumor chemoresistance. However, the role and the underlying molecular mechanism of hsa_circ_0004674 in the chemoresistance of osteosarcoma (OS) are still unclear.

Methods

The expression of hsa_circ_0004674, miR-342-3p, and fibrillin-1 (FBN1) was determined by qRT-PCR. Cell counting kit 8 assay was used to evaluate the doxorubicin (DXR) resistance of cells. The proliferation and apoptosis of cells were measured using colony formation assay and flow cytometry. Western blot analysis was utilized to examine the protein levels of resistance markers, Wnt/β-catenin pathway markers and FBN1. The interaction between miR-342-3p and hsa_circ_0004674 or FBN1 was confirmed by dual-luciferase reporter assay and RNA pull-down assay. Moreover, animal experiments were performed to assess the effect of hsa_circ_0004674 silencing on the DXR sensitive of OS in vivo.

Results

The upregulated hsa_circ_0004674 was found in DXR-resistant OS tissues and cells. Knockdown of hsa_circ_0004674 could inhibit the DXR resistance of OS cells in vitro and promote the DXR sensitive of OS tumors in vivo. In addition, we discovered that hsa_circ_0004674 could sponge miR-342-3p, and miR-342-3p could target FBN1. MiR-342-3p inhibitor could reverse the inhibition effect of hsa_circ_0004674 knockdown on the DXR resistance of OS cells. Similarly, the suppressive effect of miR-342-3p on the DXR resistance of OS cells also could be reversed by FBN1 overexpression. Furthermore, we revealed that hsa_circ_0004674 silencing inhibited the activity of Wnt/β-catenin pathway by the miR-342-3p/FBN1 axis.

Conclusion

Hsa_circ_0004674 facilitated the DXR resistance of OS through Wnt/β-catenin pathway via regulating the miR-342-3p/FBN1 axis, suggesting that hsa_circ_0004674 was a promising target for the chemoresistance of OS.

LncRNA LINC01503 aggravates the progression of cervical cancer through sponging miR-342-3p to mediate FXYD3 expression

Cervical cancer (CC), an aggressive malignancy, has a high risk of relapse and death, mainly occurring in females. Accumulating investigations have confirmed the critical role of long noncoding RNAs (lncRNAs) in diverse cancers. LncRNA LINC01503 has been reported as an oncogene in several cancers. Nonetheless, its role and molecular mechanism in CC have not been explored. In the present study, we found that FXYD3 expression was considerably up-regulated in CC tissues and cells. Moreover, FXYD3 deficiency conspicuously hampered cell proliferation and migration while facilitated cell apoptosis in CC cells. Subsequently, molecular mechanism experiments implied that FXYD3 was a downstream target gene of miR-342-3p, and FXYD3 expression was reversely mediated by miR-342-3p. Moreover, we discovered that LINC01503 acted as the endogenous sponge for miR-342-3p. Besides, LINC01503 negatively regulated miR-342-3p expression and positively regulated FXYD3 expression in CC. Rescue assays revealed that LINC01503 depletion-induced repression on CC progression could be partly recovered by miR-342-3p inhibition, and then the co-transfection of sh-FXYD3#1 rescued this effect. Conclusively, LINC01503 aggravated CC progression through sponging miR-342-3p to mediate FXYD3 expression, providing promising therapeutic targets for CC patients.

Exosomal LncRNA LINC00659 transferred from cancer-associated fibroblasts promotes colorectal cancer cell progression via miR-342-3p/ANXA2 axis

Background

Cancer-associated fibroblasts (CAFs) play a pivotal role in regulating tumor progression by transferring exosomes to adjacent cells. Our aim was to clarify the role of LINC00659 encapsulated in CAFs-derived exosomes (CAFs-exo) in colorectal cancer (CRC).

Methods

CAFs and normal fibroblasts (NFs) were isolated and cultured. CAFs-exo and NFs-derived exosomes (NFs-exo) were characterized by transmission electron microscope and Western blot. The mRNA level of LINC00659 in CAFs-exo and NFs-exo were measured. Then we analyzed cell proliferation by CCK-8 and clone formation assay, cell migration by cell scratch, and cell invasion by Transwell. Epithelial mesenchymal transformation (EMT) related markers E-cadherin, N-cadherin, Vimentin and Snail-1 expressions were assessed by Western blot. The binding of LINC00659 and miR-342-3p, miR-342-3p and ANXA2 were analyzed by dual-luciferase reporter gene assay.

Results

CAFs and NFs showed a spindle-like morphology. CAFs-exo promoted CRC cell proliferation, migration, invasion and EMT progression. The expression of LINC00659 in CAF-derived exosomes was significantly increased, and fibroblasts could transfer exosomal LINC00659 to CRC cells. We further revealed that transfection of miR-342-3p mimic or sh-ANXA2 could obviously reverse the promotion effect of exosomal LINC00659 on CRC progression. Functional studies reveal that LINC00659 is transferred from CAFs to the cancer cells via exosomes, where it promotes CRC cell proliferation, invasion, migration and EMT progression in vitro. Mechanistically, LINC00659 interacts directly with miR-342-3p to increase ANXA2 expression in CRC cells.

Conclusion

Collected evidence supported that CAFs-derived exosomal LINC00659 promotes CRC cell proliferation, invasion and migration via miR-342-3p/ANXA2axis.

Long Noncoding RNA LINC00634 Functions as an Oncogene in Esophageal Squamous Cell Carcinoma Through the miR-342-3p/Bcl2L1 Axis

Many long noncoding RNAs reportedly have tumor suppressive roles or are oncogenic in esophageal cancer. We have previously performed a chip-based expression analysis of primary esophageal cancer tissues and found that the expression of LINC00634 in these tissues was higher than that in nontumor tissues. Quantitative real-time–polymerase chain reaction, cell counting kit-8, flow cytometry, caspase3/7 assay, dual-luciferase reporter assay, and restore assay were used to detect the proliferative and apoptotic effects of LINC00634 in esophageal cancer cells. The results showed that the expression of LINC00634 in these tissues was higher than that in nontumor tissues and associated with tumor–node–metastasis (TNM) stage of patients. Knockdown of LINC00634 decreased cell viability and increased cell apoptosis levels in EC9706 and EC1 cells. LINC00634 could target Bcl2L1 through miR-342-3p. In this study, we show that LINC00634 is upregulated in esophageal cancer. We also show that the knockdown of LINC00634 decreased cell viability and increased cell apoptosis levels in EC9706 and EC1 cells through the miR-342-3p/Bcl2L1 axis.

LncRNA FTX Regulates Angiogenesis Through miR-342-3p/SPI1 Axis in Stroke

BACKGROUND

Long non-coding RNAs (lnc-RNAs) and microRNAs (miRNAs) play key roles in the development of stroke. However, the role of lncRNA FTX in stroke is limited known.

METHODS

Real-time polymerase chain reaction (real-time PCR) assays were used to measure the expression of lncRNA FTX, miR-342-3p and SPI1. Western blot assays were employed to examine SPI1 protein expression. The cell viability was measured by CCk8 assay. Cell migration was detected by wound healing assays and transwell assays. Angiogenesis was evaluated by matrigel tube formation assays. The interaction between lncRNA FTX, miR-342-3p and SPI1 was confirmed by site-directed mutagenesis and luciferase assays.

RESULTS

The expression of lncRNA FTX was down-regulated in blood sample from stroke patients, MAO mice tissues and OGD/R treated BMECs. Overexpression of lncRNA FTX could increase the cell viability, migration and angiogenesis in OGD/R treated BMECs. LncRNA FTX could act as a ceRNA for miR-342-3p. Furthermore, miR-342-3p inhibition increased migration and angiogenesis in OGD/R-induced BMECs. Dual-luciferase reporter assay verified that SPI1 was a target of miR-342-3p.

CONCLUSION

In summary, lncRNA FTX enhanced the angiogenesis in stroke by acting as a sponge of miR-342-3p to regulate the expression of SPI1 level.

[Mechanism of flavonoids of Sophorae Fructus in inhibiting proliferation, migration and invasion of hepatocellular carcinoma cells by regulating LncRNA FBXL19-AS1/miR-342-3p pathway]

The aim of this paper was to investigate the effect of flavonoids of Sophorae Fructus on the proliferation, migration and invasion of hepatocellular carcinoma cells and analyze the regulatory mechanism of LncRNA FBXL19-AS1/miR-342-3 p pathway. MTT assay and plate cloning assay were used to detect the effect of flavonoids of Sophorae Fructus at different concentrations(1, 5, 10 mg·mL~(-1)) on the proliferation of liver cancer Huh7 cells. The effect of flavonoids of Sophorae Fructus on the migration and invasion of Huh7 cells was examined by Transwell chamber assay. qRT-PCR was used to detect the effect of flavonoids of Sophorae Fructus on the expression levels of FBXL19-AS1 and miR-342-3 p in Huh7 cells. The dual luciferase reporter assay was used to detect whether FBXL19-AS1 targeted at miR-342-3 p. The effect on the inhibition of FBXL19-AS1 expression or FBXL19-AS1 overexpression and then the proliferation, migration and invasion of Huh7 cells were examined by the above methods. Gelatin zymography was used to detect the activities of MMP-2 and MMP-9. The expression levels of cyclinD1, p21, MMP-2 and MMP-9 proteins were detected by Western blot. Flavonoids of Sophorae Fructus significantly inhibited the proliferation, migration and invasion of Huh7 cells(P&lt;0.05), promoted the expression of p21 protein(P&lt;0.05), and inhibited the expressions of cyclinD1, MMP-2 and MMP-9(P&lt;0.05) in a dose-dependent manner, and could reduce the activity of MMP-2 and MMP-9(P&lt;0.05). The expression level of FBXL19-AS1 was significantly decreased in Huh7 cells treated with flavonoids of Sophorae Fructus(P&lt;0.05), whereas the expression level of miR-342-3 p was significantly increased(P&lt;0.05). The dual luciferase reporter assay confirmed that FBXL19-AS1 targeted at the inhibition of miR-342-3 p expression. After inhibiting the expression of FBXL19-AS1, the inhibition rate of cell proliferation was significantly increased(P&lt;0.05), the number of cell clone formation was significantly reduced(P&lt;0.05), the number of migrated cells and the number of invasive cells were significantly decreased(P&lt;0.05), and the expression levels of cyclinD1, MMP-2 and MMP-9 were significantly decreased(P&lt;0.05), the activities of MMP-2 and MMP-9 were significantly reduced(P&lt;0.05), while the expression level of p21 protein was significantly increased(P&lt;0.05). The overexpression of FBXL19-AS1 reversed the inhibitory effect of flavonoids of Sophorae Fructus on the proliferation, migration and invasion of Huh7 cells. Flavonoids of Sophorae Fructus could inhibite the proliferation, migration and invasion of hepatoma cells by regulating LncRNA FBXL19-AS1/miR-342-3 p pathway.

Epigenetic silencing of miR-342-3p in B cell lymphoma and its impact on autophagy

Background

miR-342-3p, localized to 14q32, is a tumor suppressor miRNA implicated in carcinogenesis. Given the presence of a promotor-associated CpG island for its host gene, EVL, we hypothesized that intronic miR-342-3p is a tumor suppressor co-regulated with host gene by promoter DNA methylation in B cell lymphoma.

Results

By bisulfite pyrosequencing-verified methylation-specific PCR (MSP), EVL/MIR342 methylation was detected in five (50%) lymphoma cell lines but not normal peripheral blood and tonsils. EVL/MIR342 methylation correlated with repression of both miR-342-3p and EVL in cell lines. In completely methylated SU-DHL-16 cells, 5-AzadC treatment resulted in promoter demethylation and re-expression of miR-342-3p and EVL. In 132 primary lymphoma samples, EVL/MIR342 was preferentially methylated in B cell lymphomas (N = 68; 68.7%) than T cell lymphoma (N = 8; 24.2%) by MSP (P < 0.0001). Moreover, EVL/MIR342 methylation was associated with lower miR-342-3p expression in 79 primary NHL (P = 0.0443). In SU-DHL-16 cells, the tumor suppressor function of miR-342-3p was demonstrated by the inhibition of cellular proliferation and increase of cell death upon over-expression of miR-342-3p. Mechanistically, overexpression of miR-342-3p resulted in a decrease of LC3-II, a biomarker of autophagy, which was pro-survival for SU-DHL-16. Pre-treatment with 3-methyladenine, an autophagy inhibitor, abrogated tumor suppression associated with miR-342-3p overexpression. By luciferase assay, MAP1LC3B, a precursor of LC3-II, was confirmed as a direct target of miR-342-3p. Finally, in SU-DHL-16 cells, overexpression of miR-342-3p downregulated the known target DNMT1, with promoter demethylation and re-expression of tumor suppressor E-cadherin.

Conclusions

Intronic miR-342-3p is co-regulated with its host gene EVL by tumor-specific promoter DNA methylation in B cell lymphoma. The tumor suppressor function of miR-342-3p was mediated via inhibition of pro-survival autophagy by targeting MAP1LC3B and downregulation of DNMT1 with demethylation and re-expression of tumor suppressor genes.

LINC01503/miR-342-3p facilitates malignancy in non-small-cell lung cancer cells via regulating LASP1

Background

Non-small cell lung cancer (NSCLC) is one of the major types of lung cancer, which is a prevalent human disease all over the world. LncRNA LINC01503 is a super-enhancer-driven long non-coding RNA that is dysregulated in several types of human cancer. However, its role in NSCLC remains unknown.

Methods

Thirty NSCLC patients were recruited between April 2012 and April 2016. Luciferase reporter assay, qRT-PCR, Cell Counting Kit-8 (CCK-8), Transwell migration assay, RNA pull-down assay, western blotting, 5-ethynyl-29-deoxyuridine (EdU) assays, and flow cytometry were utilized to characterize the roles and relationships among LINC01503, miR-342-3p, and LASP1 in NSCLC. The transplanted mouse model was built to examine their biological functions in vivo.

Results

We demonstrated that the expression of lncRNA LINC01503 and LIM and SH3 domain protein 1 (LASP1) were upregulated and miR-342-3p was downregulated in NSCLC samples and cell lines. Functional experiments revealed that inhibiting the expression of LINC01503 or over-expression of miR-342-3p inhibited NSCLC growth and metastasis both in vitro and in vivo. In addition, LINC01503 could bind to miR-342-3p and affect the expression of LASP1.

Conclusion

These results provide a comprehensive analysis of the roles of LINC01503 as a competing endogenous RNA (ceRNA) in NSCLC progression.

LncRNA LINC00210 regulated radiosensitivity of osteosarcoma cells via miR-342-3p/GFRA1 axis

BACKGROUND

Radiotherapy is an effective strategy for preventing cancer metastasis, including osteosarcoma. However, cancer radioresistance limits the efficiency of radiotherapy. Therefore, it is essential to investigate the mechanism of osteosarcoma radioresistance.

METHODS

The osteosarcoma tissues and adjacent healthy tissues were collected from 53 osteosarcoma patients. The expression of LINC00210, miR-342-3p, and GFRA1 mRNA were determined using qRT-PCR. Cell viability, cell apoptosis, and cell surviving fraction were determined by MTT assay, flow cytometry, and colony formation assay, respectively. Western blot was performed to detect the protein levels. Luciferase assay was conducted to verify the relationship between LINC00210, miR-342-3p, and GFRA1.

RESULTS

LINC00210 and GFRA1 were up-regulated, and miR-342-3p was down-regulated in osteosarcoma tissues and cells. The expression of LINC00210 in osteosarcoma was negatively related to miR-342-3p expression and positively associated with GFRA1. Besides, there was a negative correlation between LINC00210 and GFRA1 expression in osteosarcoma. Also, LINC00210 and GFRA1 were up-regulated, and miR-342-3p was down-regulated in osteosarcoma cells exposed to 4 Gy irradiation treatment. Furthermore, either LINC00210 knockdown or miR-342-3p overexpression enhanced the radiosensitivity of osteosarcoma cells. Moreover, LINC00210 increased GFRA1 expression via sponging miR-342-3p. Additionally, LINC00210 knockdown improved the radiosensitivity of osteosarcoma cells by regulating GFRA1 expression via sponging miR-342-3p.

CONCLUSION

LINC00210 modulated the radiosensitivity of osteosarcoma cells via the miR-342-3p/GFRA1 axis, making LINC00210 a novel target for improving radiotherapy efficiency in osteosarcoma.

LncRNA SNHG7 promotes glioma cells viability, migration and invasion by regulating miR-342-3p/AKT2 axis

PURPOSE

Glioma has been categorized as the most common primary malignant brain tumor. Long non-coding RNA SNHG7 (lncRNA SNHG7) has been recognized in various cancers as a possible oncogene. In this study, the effect of SNHG7 on glioma cells was investigated.

MATERIALS AND METHODS

Thirty glioma tissues and adjacent normal tissues were collected. Pc-SNHG7, sh-SNHG7, miR-342-3p mimic and miR-342-3p inhibitor were transfected into the glioma cells. Cell Counting Kit-8, Transwell and scratch assay evaluated glioma cells viability, invasion and migration, respectively. TargetScan, Starbase and dual-luciferase reporter were used to predict and confirm the target genes and potential binding sites of SNHG7, miR-342-3p and AKT2. Relative miR-342-3p and AKT2 expressions were assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Pearson's analysis was adopted for correlation analysis between SNHG7, miR-342-3p and AKT2.

RESULTS

SNHG7 expressions in glioma tissues and cells were increased, upregulation of SNHG7 promotes cell viability, invasion and migration. SNHG7 was shown to bind with miR-342-3p, and upregulating SNHG7 reduced miR-342-3p expression. AKT2 was the target gene of miR-342-3p, and miR-342-3p expression was decreased while AKT2 expression was increased in glioma tissues. High expression of miR-342-3p inhibited cell viability, invasion and migration and reduced AKT2 expression, whereas low expression of miR-342-3p did the opposite effect.

CONCLUSIONS

Upregulating SNHG7 might promote glioma cells viability, migration and invasion with the regulation of decreasing miR-342-3p level and increasing AKT2 level.

Long non-coding RNA SCARNA2 induces cutaneous squamous cell carcinoma progression via modulating miR-342-3p expression

BACKGROUND

Long non-coding RNAs (lncRNAs) play important roles in the progression of tumors. However, the function and expression of SCARNA2 in cutaneous squamous cell carcinoma (cSCC) is still unreported.

METHODS

A quantitative polymerase chain reaction was applied to study the expression of SCARNA2 and miR-342-3p. Cell counting kit-8, flow cytometry and transwell assays were performed to study cell growth, cycle and cell invasion.

RESULTS

We found that SCARNA2 expression is up-regulated in cSCC cell lines and SCARNA2 expression is higher in cSCC tissues than in adjacent non-tumor specimens. Ectopic expression of SCARNA2 promoted cell growth, cell cycle and invasion in SCC13 cells. In addition, the data indicate that miR-342-3p expression is down-regulated in cSCC cell lines and miR-342-3p is down-regulated in cSCC tissues compared to adjacent non-tumor specimens. We showed that the SCARNA2 expression is negatively associated with miR-342-3p in cSCC. Moreover, we noted that SCARNA2 sponges miR-342-3p expression in cSCC cells. Overexpression of SCARNA2 suppressed the miR-342-3p expressed in SCC13 cells. We found that elevated expression of SCARNA2 promotes cell growth, cell cycle and invasion via regulating miR-342-3p expression in SCC13 cells.

CONCLUSIONS

These data suggest that SCARNA2 acts in an oncogenic role and may be a potential target for cSCC.

Long noncoding RNA LINC00460 conduces to tumor growth and metastasis of hepatocellular carcinoma through miR-342-3p-dependent AGR2 up-regulation

Hepatocellular carcinoma (HCC) is the fifth most common malignant tumor in the world. It ranks third among cancer-induced deaths worldwide and has the characteristics of high metastasis and high recurrence rate. Long non-coding RNA (LncRNA) LINC00460 is significantly up-regulated in multiple types of cancers and is closely related to the progression of tumors. However, effects of LINC00460 and corresponding regulatory path in HCC are still poorly investigated.

In our study, we found that expression of LINC00460 was up-regulated in HCC tissues and cell lines compared with the control. Then we revealed that knockdown of LINC00460 suppressed cell proliferation and cell mobility and induced cell apoptosis in HCC cells. Further study demonstrated that knockdown of LINC00460 suppressed the progression of HCC by elevating the expression of microRNA (miRNA, miR)-342-3p. Besides that, metastasis marker, Anterior gradient homolog 2 (AGR2) was found to be a target of miR-342-3p and overexpression of AGR2 promoted the progression of HCC. Finally, the in vivo experiments further verified the anti-tumor effects of LINC00460 / miR-342-3p / AGR2 axis in HCC.

The LINC00460 / miR-342-3p / AGR2 axis exerts anti-tumor effect in HCC in vitro and in vivo, consolidating and expanding the research about targeted gene therapy for early diagnosis and treatment of HCC.

LncRNA LINC00313 Knockdown Inhibits Tumorigenesis and Metastasis in Human Osteosarcoma by Upregulating FOSL2 through Sponging miR-342-3p

PURPOSE

Osteosarcoma (OS) is the most common primary bone tumor, with high morbidity in infants and adolescents. Long noncoding RNA LINC00313 has been found to modulate papillary thyroid cancer tumorigenesis and to be dysregulate in lung cancer. However, the role of LINC00313 in OS has not yet been addressed.

MATERIALS AND METHODS

We evaluated mRNA and protein expression using real-time quantitative PCR and Western blotting. Cell proliferation was evaluated using MTT; apoptosis and autophagy were assessed with flow cytometry, Western blotting, and/or GFP-LC3 assay. Transwell assay was conducted to measure cell migration and invasion. Potential target sites for LINC00313 and miR-342-3p were predicted with starBase v.2.0 and TargetScan Human, and verified using luciferase reporter assay, RNA immunoprecipitation, and RNA pull-down assay. In vivo, xenogeneic tumors were induced with U2OS and MG-63 cells, separately.

RESULTS

LINC00313 was upregulated and miR-342-3p was downregulated in OS tissues and cells. High expression of LINC00313 was associated with shorter overall survival. FOSL2 downregulation and miR-342-3p overexpression suppressed cell proliferation and migratory and invasive abilities while promoting apoptosis and autophagy, all of which were consistent with the effects of LINC00313 knockdown. miR-342-3p, sponged by LINC00313, inversely modulated FOSL2 by targeting MG-63 cells, and FOSL2 expression was positively controlled by LINC00313. LINC00313 knockdown suppressed tumor growth in vivo.

CONCLUSION

LINC00313 is upregulated in OS, and LINC00313 knockdown plays a vital anti-tumor role in OS cell progression through a miR-342-3p/FOSL2 axis. Our study suggests that LINC00313 may be a novel, promising biomarker for diagnosis and prognosis of OS.

Downregulation of lncRNA ZEB1-AS1 Represses Cell Proliferation, Migration, and Invasion Through Mediating PI3K/AKT/mTOR Signaling by miR-342-3p/CUL4B Axis in Prostate Cancer

Background: Prostate cancer (PCa) is the second most common cancer among men, threatening men's health and life. Long noncoding RNA Zinc-finger E-box binding homeobox 1 antisense gene 1 (ZEB1-AS1) and Cullin 4B (CUL4B) were reported to be connected with the tumorigenesis of PCa. However, it is unclear whether ZEB1-AS1 regulates the expression of CUL4B in PCa. Materials and Methods: The levels of ZEB1-AS1 and CUL4B in PCa tissues and cells were evaluated by quantitative real-time polymerase chain reaction. Protein levels of CUL4B, p21, CyclinD1, matrix metalloprotease 9 (MMP9), E-cadherin, phosphorylated-phosphatidylinositol 3 kinase (p-PI3K), PI3K phosphorylated protein kinase B (p-AKT), AKT, p-mTOR and mammalian target of rapamycin (mTOR) in PCa tissues or cells were assessed by Western blot analysis. The proliferation, migration, and invasion abilities of PCa cells were determined with 3-(4, 5-dimethylthiazol-2-YI)-2,5-diphenyltetrazolium bromide (MTT) or transwell assay. The interaction between ZEB1-AS1 or CUL4B and microRNA-342-3p (miR-342-3p) was predicted using starBase v2.0 database and confirmed by the dual-luciferase reporter assay. Results: ZEB1-AS1 and CUL4B were upregulated and miR-342-3p was downregulated in PCa tissues and cells. Both ZEB1-AS1 and CUL4B inhibition constrained proliferation, migration, and invasion of PCa cells. Moreover, the elevation of CUL4B reversed the effects of ZEB1-AS1 silencing on the proliferation, migration, and invasion of PCa cells. Importantly, ZEB1-AS1 modulated CUL4B expression by sponging miR-342-3p in PCa cells. Besides, ZEB1-AS1 mediated PI3K/AKT/mTOR signal pathway by miR-342-3p/CUL4B axis in PCa cells. Conclusion: ZEB1-AS1 modulated PCa progression through mediating PI3K/AKT/mTOR signaling by miR-342-3p/CUL4B axis, providing a possible strategy for the treatment of PCa.

Long Noncoding RNA LINC00460 Promotes Hepatocellular Carcinoma Progression via Regulation of miR-342-3p/AGR2 Axis

Background

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide. LINC00460, a novel long non-coding RNA (lncRNA), was recently confirmed as an oncogene in various cancers. However, the biological function and underlying mechanism of LINC00460 in HCC is largely obscure.

Methods

Fifty pairs of tumor tissue and adjacent normal tissues from HCC patients, as well as six HCC cell lines and a normal human hepatic epithelial cell line were subjected to qRT-PCR assay to evaluate the expression levels of LINC00460. CCK-8 assays were used to detect the proliferation of HCC cells. Transwell assay was used to measure the migration and invasion abilities of HCC cells. RNA pull-down and luciferase assays were performed to verify the direct interaction between LINC00460 and miR-342-3p. A xenograft model of HCC was established to validate the in vivo function of LINC00460 in HCC progression.

Results

We firstly detected LINC00460 expression was significantly upregulated in both HCC tumor tissues and cell lines. The upregulation of LINC00460 was positively associated with HCC progression. Functionally, LINC00460 facilitated HCC cell proliferation, migration, and invasion capacities, which due to that LINC00460 could physically bind to and repress miR-342-3p to elevate the expression of AGR2.

Conclusion

Our data firstly reveal the clinical relevance, biological function, and regulatory mechanism of LINC00460 in HCC development. LINC00460 promotes HCC progression by elevating AGR2 expression via sponging miR-342-3p, providing a promising therapeutic target for HCC treatment.

Identification of potential microRNAs and their targets in promoting gefitinib resistance by integrative network analysis

Background

Non-small cell lung cancer (NSCLC) accounts for about 80-85% of lung cancers. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as gefitinib are considered the best choice for first-line treatment for the patients with NSCLC harboring EGFR-activating alterations. Nonetheless, 10-30% of patients may not obtain an objective response and may also experience rapid progression. The aim of our research, based on the integrative bioinformatics review, was to identify the possible miRNAs involved in gefitinib resistance.

Method

A gefitinib-resistant network composed of 15 miRNAs and 34 targets were constructed by using the bioinformatics analyses of three microarray datasets. Of these miRNAs, effects of miR-342-3p on gefitinib resistance were investigated on a gefitinib-resistant cell model (A549/GR and PC/GR cells).

Results

We reported that over-expression of miR-342-3p could significantly increase the resistance to gefitinib of A549/GR and PC9/GR cells and vice versa. Then, we recognized CPA4 as a target of hsa-miR-342-3p by a luciferase reporter assay. The increase in hsa-miR-342-3p levels led to a significant reduction in CPA4 protein expression. However, the opposite results were observed upon miR-342-3p knockdown. Finally, we found that enforced CPA4 expression partially reversed miR-342-3p effects in A549/GR cells.

Conclusions

Collectively, these findings suggest that the upregulation of miR-342-3p contributes to gefitinib resistance by targeting CPA4, which may serve as a potential treatment option to overcome gefitinib resistance in patients with NSCLC.

Knockdown of lncRNA SNHG16 suppresses multiple myeloma cell proliferation by sponging miR-342-3p

Background

Aberrant expression of long non-coding RNAs (lncRNAs) is closely associated with development and prognosis of human cancers. LncRNA SNHG16 is reportedly involved in human cancer; however, its roles in multiple myeloma (MM) remain unclear.

Methods

In this study, we investigated the function and molecular mechanisms of SNHG16 in MM. MM cells were transfected with si-SNHG16 or si-NC. SNHG16 expression levels was measured by qRT-PCR. Cell proliferation was monitored using the MTS. Flow cytometry assay was performed to measure the cell cycle and apoptosis. Luciferase reporter assay were performed to confirm the sponged miRNAs of SNHG16.

Results

SNHG16 expression was up-regulated in MM tissues. SNHG16 knockdown suppressed cell proliferation, arrested cell cycle transition from G1 to S phase, and promoted the apoptosis of MM cells. Moreover, SNHG16 knockdown promoted cleaved-Caspase-3, cleaved-Caspase-9, Foxa3a, and Bax expression, while markedly inhibiting CCND1, Bcl-2, Cyclin D1, PI3K, and p-AKT expression in MM cells. miR-342-3p was a direct target of SNHG16. SNHG16 knockdown significantly increased miR-342-3p expression in MM cells. Overexpression miR-342-3p markedly suppressed cell proliferation, arrested cell cycle transition from G1 to S phase, and promoted apoptosis of MM cells. Overexpression of miR-342-3p markedly promoted cleaved-Caspase-3/-9, Foxa3a, and Bax expression, and inhibited CCND1, Bcl-2, Cyclin D1, PI3K, and p-AKT expression in MM cells. Additionally, repression of miR-342-3p could rescue the effect of SNHG16 knockdown on MM cell proliferation, cycle arrest, apoptosis, and related protein expression.

Conclusion

Knockdown of lncRNA SNHG16 suppresses MM cell proliferation by sponging miR-342-3p, implicating SNHG16 as a novel therapeutic target for MM.

Circular RNA CCDC66 facilitates abdominal aortic aneurysm through the overexpression of CCDC66

Abdominal aortic aneurysm (AAA) is fatal meanwhile unpredictable asymptomatic cardiovascular disease. Available data suggests the potential participation of circular RNAs (circRNAs) in AAA pathogenesis. But direct evidence is limited. The present study is to functionally and mechanically characterize circRNA CCDC66 (circCCDC66) in AAA. Previous work indicated the differentially expressed circCCDC66 in AAA. At molecular level, circCCDC66, miR-342-3p and CCDC66 transcript were measured through real-time quantitative polymerase chain reaction assay. Functionally, we examined the cellular behaviours of circCCDC66-depleted or CCDC66-depleted vascular smooth muscle cells (VSMCs) including proliferation and apoptosis. It elucidated that depletion of circCCDC66 induced proliferation facilitation and apoptosis reduction. Mechanically, we addressed the interplay among circCCDC66, miR-342-3p and CCDC66 transcript using RNA immunoprecipitation, RNA pull-down and luciferase reporter experiments. Through mechanical validation, we discovered the positive regulation of circCCDC66 on its host gene CCDC66. Loss of CCDC66 mimicked the effects of circCCDC66 silencing on VSMC growth. Moreover, it uncovered that circCCDC66 regulated CCDC66-dependent VSMC growth through sponging miR-342-3p. Rescue experiments aimed to address the functional role of regulatory network formed by circCCDC66, miR-342-3p and CCDC66 in VSMC growth and apoptosis. Suppressing miR-342-3p or overexpressing CCDC66 could reverse VSMC growth caused by circCCDC66 deficiency. Our study further emphasized and first unveiled the function of circCCDC66 in VSMC proliferation. CircCCDC66 upregulated its host gene through its role of miR-342-3p sponge, and hinted a novel molecular mechanism in AAA. SIGNIFICANCE OF THE STUDY: It was firstly displayed in our study that depletion of circCCDC66 induced proliferation augmentation and apoptosis reduction of vascular smooth muscle cells (VSMCs). Meanwhile, circCCDC66/miR-342-3p/CCDC66 axis was proved can play the function of modulating the cell proliferation and apoptosis of VSMCs, which provided us a novel molecular mechanism in AAA.

MiR-342-3p inhibition promotes cell proliferation and invasion by directly targeting ID4 in pre-eclampsia

AIM

This study aimed to explore the miR-342-3p expression in pre-eclampsia (PE) placentas and confirm whether miR-342-3p exerts effects on proliferation and migration of HTR-8/SVneo trophoblastic cells.

METHODS

The PE placentas (n = 8) were taken from gravidas complicated by PE and delivered after 34 weeks. The chorionic plates and the basal plates were separately taken from the placenta disc near the position of umbilical cord insertion. RT-qPCR was used to measure the expression of miR-342-3p in the chorionic plates and the basal plates. Cell invasion assay and MMT assay were used to assess the effects of miR-342-3p on proliferation and migration of HTR-8/SVneo trophoblastic cells. Luciferase reporter assay and Western blotting were used to analyze the target of miR-342-3p and investigate the detailed mechanisms.

RESULTS

The expression of miR-342-3p was upregulated in both basal plates and chorionic plates in patients with PE compared with healthy pregnant individuals. MiR-342-3p inhibitor suppressed the cell viability and invasion, and induced apoptosis in trophoblast cells. Furthermore, inhibitor of DNA binding (ID)-4 (ID4) was a direct target of miR-342-3p, and knockdown of ID4 abrogated the regulation effect of miR-342-3p on cell viability, apoptosis and invasion.

CONCLUSION

Inhibition of miR-342-3p expression may suppress the occurrence of PE by targeting ID4 in vitro.

LncRNA H19 over-expression inhibited Th17 cell differentiation to relieve endometriosis through miR-342-3p/IER3 pathway

Objective

To investigate the mechanism of LncRNA H19 in Th17 cell differentiation and endometrial stromal cells (ESCs) proliferation in endometriosis (EMS).

Methods

LncRNA H19, miR-342-3p and IER3 expressions were detected by qRT-PCR and western blot. The percentage of Th17 cells/CD4+ T cells was detected by flow cytometry. IL-17 level was measured by ELISA. The interaction of miR-342-3p and IER3 was confirmed by Luciferase reporter assay.

Results

LncRNA H19 and IER3 expressions were down-regulated in mononuclear cells from peritoneal fluid (PFMCs) of patients with EMS or under Th17 differentiation conditions, whereas miR-342-3p expression was up-regulated and the percentage of Th17 cells was increased in PFMCs of patients with EMS or under Th17 differentiation conditions. Over-expression of LncRNA H19 decreased IL-17 level and the percentage of Th17 cells/CD4+ T cells. Besides, we confirmed that miR-342-3p could target to IER3 and negatively regulate IER3 expression. LncRNA H19 over-expression suppressed Th17 differentiation and ESC proliferation through regulating miR-342-3p/IER3. In vivo experiments showed LncRNA H19 over-expression suppressed the growth of Th17 cell differentiation-induced endometriosis-like lesions.

Conclusion

LncRNA H19 was down-regulated in PFMC of patients with EMS or under Th17 polarizing conditions, and LncRNA H19 over-expression suppressed Th17 cell differentiation and ESCs proliferation through miR-342-3p/IER3 pathway.

microRNA-342-3p targets FOXQ1 to suppress the aggressive phenotype of nasopharyngeal carcinoma cells

Background

microRNA (miR)-342–3p is frequently dysregulated in human cancers. In the present study, we aimed to explore the expression, prognostic significance, and biological relevance of miR-342-3p in nasopharyngeal carcinoma (NPC).

Methods

We examined miR-342-3p expression in 79 paired NPC specimens and corresponding normal tissues and analyzed its prognostic impact on overall survival of NPC patients. Gain- and loss-of-function experiments were conducted to determine the biological roles of miR-342-3p.

Results

Compared with matched normal nasopharyngeal tissues, miR-342-3p was significantly downregulated in NPC (P = 0.0038). Low miR-342-3p expression was significantly correlated with reduced overall survival (P = 0.0084). Ectopic expression of miR-342-3p significantly suppressed proliferation, colony formation, and invasion of NPC cells. In contrast, depletion of miR-342-3p facilitated NPC cell proliferation and invasion. In vivo xenograft studies confirmed that overexpression of miR-342-3p restrained the growth of NPC xenograft tumors. Mechanistically, FOXQ1 served as a functional target of miR-342-3p. There was a significantly negative correlation between miR-342-3p and FOXQ1 expression (r = − 0.487, P = 0.004) in NPC specimens. Overexpression of FOXQ1 rescued the inhibitory effects of miR-342-3p on NPC cell growth and invasion.

Conclusions

miR-342-3p downregulation predicts poor prognosis in NPC patients and shows suppressive activity against NPC growth and invasion through repression of FOXQ1. Restoration of miR-342-3p may represent a potential therapeutic strategy for NPC.

LINC00460 modulates KDM2A to promote cell proliferation and migration by targeting miR-342-3p in gastric cancer

Background

Increasing evidence has shown that long non-coding RNAs (lncRNAs) play important roles in the occurrence and development of human cancers. LINC00460, a novel tumor-related lncRNA, has been reported to be involved in several types of human malignancies. However, the role of LINC00460 in gastric cancer (GC) is still unclear. The present study aimed at exploring the biological role of LINC00460 in GC and illuminating the potential molecular mechanisms.

Methods

In this study, qRT-PCR, western blotting, MTT assay, and Transwell invasion assay were used to conduct relevant experimental analysis.

Results

Here, we found that LINC00460 was highly expressed in GC tissues and cell lines. Moreover, LINC00460 overexpression was found to promote GC cell proliferation, migration and invasion, whereas LINC00460 down-regulation significantly inhibited these processes. Notably, we confirmed that LINC00460 could up-regulate KDM2A expression by competitively binding to miR-342-3p in GC cells. Furthermore, the suppressive effects of LINC00460 down-regulation on GC cell proliferation, migration and invasion were partially reversed by a miR-342-3p inhibitor.

Conclusion

In summary, our findings provide evidence for LINC00460 as a potential therapeutic target in GC.

Blockade of NEAT1 represses inflammation response and lipid uptake via modulating miR-342-3p in human macrophages THP-1 cells

Atherosclerosis has been recognized as a chronic inflammation process induced by lipid of the vessel wall. Oxidized low-density lipoprotein (ox-LDL) can drive atherosclerosis progression involving macrophages. Recently, long noncoding RNAs (lncRNAs) have been reported to play critical roles in atherosclerosis development. In our current study, we focused on the biological roles of lncRNA NEAT1 in atherosclerosis progress. Here, we found that ox-LDL was able to trigger human macrophages THP-1 cells, a human monocytic cell line, apoptosis in a dose-dependent and time-dependent course. In addition, we observed that NEAT1 was significantly increased in THP-1 cells incubated with ox-LDL and meanwhile miR-342-3p was greatly decreased. Then, NEAT1 was silenced by transfection of small interfering RNA (siRNA) of NEAT1 into THP-1 cells. As exhibited, CD36, oil-red staining levels, total cholesterol (TC), total cholesterol (TG) levels and THP-1 cell apoptosis were obviously repressed by knockdown of NEAT1. Furthermore, inhibition of NEAT1 contributed to the repression of inflammation in vitro. Interleukin 6 (IL-6), IL-1β, cyclooxygenase-2 (COX-2) and tumour necrosis factor-alpha (TNF-α) protein levels were remarkably depressed by NEAT1 siRNA in THP-1 cells. By using bioinformatics analysis, miR-342-3p was predicted as a downstream target of NEAT1 and the correlation between them was confirmed in our study. Moreover, overexpression of miR-342-3p could also greatly suppress inflammation response and lipid uptake in THP-1 cells. Knockdown of NEAT1 and miR-342-3p mimics inhibited lipid uptake in THP-1 cells. In conclusion, we implied that blockade of NEAT1 repressed inflammation response through modulating miR-342-3p in human macrophages THP-1 cells and NEAT1 may offer a promising strategy to treat atherosclerotic cardiovascular diseases.

T2DM inhibition of endothelial miR-342-3p facilitates angiogenic dysfunction via repression of FGF11 signaling

Understanding the function and molecular relevance of distinct miRNAs in endothelial cells (ECs) paves avenues for possible therapeutic intervention by targeting epigenetic mechanisms in vascular endothelial dysfunction, one of the major complications of type 2 diabetes mellitus (T2DM). MiR-342-3p, an obesity-associated miRNA, has recently been shown to be significantly upregulated in human angiosarcoma compared to benign hemangioma, indicating its potential involvement as a proangiogenic factor. Herein, we show that endothelial miR-342-3p expression was significantly compromised in T2DM organisms and this inhibition powerfully blocked vasculogenesis in vivo by repressing endothelial proliferation and migration. From a mechanistic standpoint, miR-342-3p promoted the transactivation of fibroblast growth factor 11 (FGF11) by directly targeting its 3' untranslated regions (3'UTRs). Functionally, overexpression of exogenous FGF11 successfully rescued miR-342-3p deficiency-impaired endothelial proliferation and migration. Thus, perturbation of miR-342-3p/FGF11 cascade by hyperinsulinemia plays a causative role in the induction of vascular dysfunction in T2DM. Overall, the current study underscore an endothelial facet of miR-342-3p, which may operate as a novel epigenetic integrator linking adipogenic homeostasis and angiogenesis.

Metadherin is an apoptotic modulator in prostate cancer through miR-342-3p regulation

Prostate cancer is the second most common cancer in men worldwide. This study focused to clarify the roles of Metadherin (MTDH) and miR-342-3p in prostate cancer. We identified that MTDH was up-regulated and miR-342-3p was down-regulated in the prostate tissues, and there is an inverse correlation between MTDH and miR-342-3p. Functional studies revealed that miR-342-3p directly targets MTDH via binding to the 3' untranslated regions (UTRs) in the prostate cancer cells. Moreover, we also found MTDH overexpression in DU145 and PC3 cells inhibited apoptosis. Subsequently, miR-342-3p has been revealed to reverse the MTDH effect on the cellular apoptosis in the further studies. Our results indicate that MTDH repress apoptosis of prostate cancer in vitro and provides a new strategy for human prostate cancer therapy in the future.

miR-342-3p suppresses hepatocellular carcinoma proliferation through inhibition of IGF-1R-mediated Warburg effect

Background

Insulin-like growth factor-1 receptor (IGF-1R) is a well-studied oncogenic factor that promotes cell proliferation and energy metabolism and is overexpressed in numerous cancers including hepatocellular carcinoma (HCC). Aerobic glycolysis is a hallmark of cancer, and drugs targeting its regulators, including IGF-1R, are being developed. However, the mechanisms of IGF-1R inhibition and the physiological significance of the IGF-1R inhibitors in cancer cells are unclear.

Materials and methods

Cell proliferation was evaluated by cell counting Kit-8 and colony formation assay. Western blot and real-time PCR were accordingly used to detect the relevant proteins, miRNA and gene expression. Luciferase reporter assays were used to illustrate the interaction between miR-342-3p and IGF-1R. The effect of miR-342-3p on glycolysis was determined by glucose uptake, ATP concentration, lactate generation, extracellular acidification rate and oxygen consumption rate assays. In vivo, subcutaneous tumor formation assay and PET were performed in nude mice.

Results

In this study, we demonstrate that by directly targeting the 3′-UTR (3′-untranslated regions) of IGF-1R, microRNA-342-3p (miR-342-3p) suppresses IGF-1R-mediated PI3K/AKT/GLUT1 signaling pathway both in vitro and in vivo. Through suppression of IGF-1R, miR-342-3p dampens glycolysis by decreasing glucose uptake, lactate generation, ATP production, and extracellular acidification rate (ECAR), and increasing oxygen consumption rate (OCR) in hepatoma cells. Importantly, glycolysis regulated by miR-342-3p is critical for its regulating HCC growth both in vitro and in vivo.

Conclusion

Our findings provide clues regarding the role of miR-342-3p as a tumor suppressor in liver cancer mainly through the inhibition of IGF-1R. Targeting IGF-1R by miR-342-3p could be a potential therapeutic strategy in liver cancer.

MicroRNA expression profiles and clinicopathological implications in lung adenocarcinoma according to EGFR, KRAS, and ALK status

Lung adenocarcinoma has distinctive clinicopathological features that are related to specific genetic alterations, including EGFR and KRAS mutations and ALK rearrangement. MicroRNAs are small non-coding RNAs that post-transcriptionally regulate many important biological processes and influence cancer phenotypes. This study retrospectively investigated microRNA expression profiles, and their clinicopathological implications, in lung adenocarcinoma according to genetic status (EGFR, KRAS, ALK, and triple negative). A total of 72 surgically resected lung adenocarcinoma specimens (19 EGFR-mutated, 17 KRAS-mutated, 16 ALK-rearranged, and 20 triple negative cancers) were screened for 23 microRNAs using quantitative real-time reverse transcriptase polymerase chain reaction. We then evaluated the associations between the microRNA expressions and the cancers’ genetic and clinicopathological features. Eight microRNAs were associated with clinicopathological features, such as male sex and ever-smoker status (high miR-373-3p, miR-1343-3p, miR-138-1-3p, and miR-764; low miR-27b-3p) and vascular invasion (high miR-27b-3p; low miR-1343-3p and miR-764). Clustering and discriminant analyses revealed that the microRNA expression patterns in the ALK group were different from those in the EGFR and KRAS groups. Five microRNAs (high miR-1343-3p; low miR-671-3p, miR-103a-3p, let-7e, and miR-342-3p) were especially distinctive in the ALK group, compared to the EGFR and KRAS groups. Moreover, a significant association was observed between ALK-rearrangement, decreased miR-342-3p expression, and immunohistochemical loss of E-cadherin. Therefore, microRNA expression profiles appear to have distinctive clinicopathological implications in ALK-rearranged lung adenocarcinoma. Furthermore, the association of ALK rearrangement, decreased miR-342-3p expression, and E-cadherin loss might indicate that miR-342-3p is involved in the ALK-associated phenotypes and epithelial-mesenchymal transition.

miR-342-3p suppresses cell proliferation and migration by targeting AGR2 in non-small cell lung cancer

AGR2 is a well-studied secreted protein that is involved in multiple biological processes including cell proliferation and migration. The mechanism by which AGR2 increases the growth and migration of non-small cell lung cancer cells (NSCLC) is still unknown. In this study, we report that AGR2 is directly targeted by miR-342-3p. Functional studies suggest that overexpression of miR-342-3p inhibits the proliferation and migration of non-small cell lung cancer cells. Overexpression of AGR2 counteracts the phenotypes induced by miR-342-3p. Moreover, AGR2 expression is up-regulated and negatively correlated with miR-342-3p levels in NSCLC cells and tissues. A meta-analysis of survival data indicates that NSCLC patients with high levels of AGR2 in their tumors have a worse prognosis. Collectively, the identification of miR-342-3p and AGR2 might facilitate the development of biomarkers and therapeutic targets for this devastating disease.

miR-342-3p elevates osteogenic differentiation of umbilical cord mesenchymal stem cells via inhibiting Sufu in vitro

Human umbilical mesenchymal stem cells (UCMSCs) have been wildly used in tissue engineering field as a promising source because of their unlimited and noninvasive origin. To selectively induce osteogenic differentiation of UCMSCs, it's imperative to understand the regulatory molecular mechanism underlying the process of how these cells switch into osteogenic lineage path. We previously showed enhanced sonic hedgehog (Shh) signaling pathway upon osteogenic induction in mesenchymal stem cells. In this study, miRNA-seq analysis revealed substantial Shh-dependent expression of distinct miRNAs, including miR-342-3p, during ostogenesis. RT-qPCR confirmed that miR-342-3p was increased at a greater level when Shh signaling pathway was activated by N-terminal of Shh ligand compared with osteogenic induction alone, in contrast to the decreasing of suppressor-of-fused protein (Sufu). Consistently, transient overexpressing miR342-3p in UCMSCs via miR-342-3p mimics dramatically decreased Sufu, a suppressor of Gli, while osteogenic markers, including alkaline phosphate and osteocalcin, were upregulated during osteogenic induction, indicating that miR-342-3p might be involved in osteogenesis through the Shh signaling pathway. In conclusion, this study showed the potential of miR-342-3p as a therapeutic target to promote bone regeneration by modulating expression of Sufu in UCMSCs.

Long non-coding RNA H19 regulates FOXM1 expression by competitively binding endogenous miR-342-3p in gallbladder cancer

Background

Long non-coding RNA (lncRNA) H19 has been reported to involve in many kinds of human cancers and functions as an oncogene. Our previous study found that H19 was over-expressed in gallbladder cancer (GBC) and was shown to promote tumor development in GBC. However, the competing endogenous RNA (ceRNA) regulatory network involving H19 in GBC progression has not been fully elucidated. We aim to detect the role of H19 as a ceRNA in GBC.

Methods and Results

In this study, the expression of H19 and miR-342-3p were analyzed in 35 GBC tissues and matched normal tissues by using quantitative polymerase chain reaction (qRT-PCR). We demonstrated H19 was overexpressed and negatively correlated with miR-342-3p in GBC. By dual-luciferase reporter assays, RNA-binding protein immunoprecipitation (RIP) and RNA pull-down assays, we verified that H19 was identified as a direct target of miR-342-3p. QRT-PCR and Western-blotting assays demonstrated that H19 silencing down-regulated, whereas over-expression enhanced the expression of miR-342-3p targeting FOXM1 through competitively ‘sponging’ miR-342-3p. Furthermore, transwell invasion assays and cell cycle assays indicated that H19 knockdown inhibited both cells invasion and proliferation, but this effects was attenuated by co-transfection of siRNA-H19 and miR-342-3p inhibitor in GBC cells. In vivo, tumor volumes were decreased significantly in H19 silenced group compared to the control group, but was attenuated by co-transfection of shRNA-H19 and miR-342-3p inhibitor, which were stablely constructed through lenti-virus vector.

Conclusion

Our results suggest a potential ceRNA regulatory network involving H19 regulates FOXM1 expression by competitively binding endogenous miR-342-3p in GBC. This mechanism may contribute to a better understanding of GBC pathogenesis and provides potential therapeutic strategy for GBC.

Expression of microRNA-10a, microRNA-342-3p and their predicted target gene TIAM1 in extranodal NK/T-cell lymphoma, nasal type

MicroRNAs (miRNAs) may act as oncogenes or tumor suppressor genes in different types of human cancer. T-lymphoma invasion and metastasis inducing factor 1 (TIAM1) participates in the development of several types of human cancer. However, the expression of miRNAs and TIAM1 in extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTCL) remains poorly understood. In the present study, the association between the expression levels of miR-10a and miR-342-3p and the protein expression levels of TIAM1 was examined in ENKTCL tissues. The expression levels of miR-10a, miR-22, miR-340, miR-342-3p and miR-590-5p in 15 primary ENKTCL tissues were analyzed using quantitative polymerase chain reaction, and the protein expression levels of TIAM1 in 21 primary ENKTCL tissues were analyzed using immunohistochemistry. The expression levels of miR-10a and miR-342-3p were lower in ENKTCL tissues than in normal NK cells, but no significant differences were observed in the expression levels of miR-22, miR-340 and miR-590-5p in ENKTCL tissues, compared with normal NK cells. The low expression levels of miR-10a detected in the tissues of patients with ENKTCL were inversely correlated with the age of the patients, whereas the low expression levels of miR-342-3p measured in these samples were not correlated with any demographic or clinical features of the patients. The protein expression levels of TIAM1 were higher in ENKTCL tissues than in normal and reactive lymph node hyperplasia tissues, and positively correlated with the Ann Arbor stage and international prognostic index score of the tumors. Furthermore, the expression levels of miRNA-10a and miRNA-342-3p were inversely correlated with the protein expression levels of TIAM1 in ENKTCL tissues. These data suggest that TIAM1 may contribute to the pathogenesis of ENKTCL, and miRNA-10a and miRNA-342-3p may be involved in the development of ENKTCL via the TIAM1 pathway.

miR-342-3p affects hepatocellular carcinoma cell proliferation via regulating NF-κB pathway

Recent research indicates that non-coding microRNAs (miRNAs) help regulate basic cellular processes in many types of cancer cells. We hypothesized that overexpression of miR-342-3p might affect proliferation of hepatocellular carcinoma (HCC) cells. After confirming overexpression of miR-342-3p with qRT-PCR, MTT assay showed that HCC cell proliferation was significantly inhibited by miR-342-3p, and that it significantly decreased BrdU-positive cell proliferation by nearly sixfold. Searching for targets using three algorithms we found that miR-342-3p is related to the NF-κB pathway and luciferase assay found that IKK-γ, TAB2 and TAB3 are miR-342-3p target genes. Results of western blot on extracted nuclear proteins of HepG2 and HCT-116 cells showed that miR-342-3p reduced and miR-342-3p-in increased p65 nuclear levels and qRT-PCR found that NF-κB pathway downstream genes were downregulated by miR-342-3p and upregulated by miR-342-3p-in, confirming that miR-342 targets NF-κB pathway. Overexpression of Ikk-γ, TAB2 and TAB3 partially rescued HCC cells proliferation inhibited by miR-342-3p. Using the GSE54751 database we evaluated expression from 10 HCC samples, which strongly suggested downregulation of miR-342-3p and we also found inverse expression between miR-342-3p and its targets IKK-γ, TAB2 and TAB3 from 71 HCC samples. Our results show that miR-342-3p has a significant role in HCC cell proliferation and is suitable for investigation of therapeutic targets.

Prognostic value of miR-221-3p, miR-342-3p and miR-491-5p expression in colon cancer

Increasing evidence has demonstrated that microRNAs (miRNAs) are involved in colon cancer initiation and progression, and may serve as diagnostic and prognostic biomarkers for colon cancer. Here, we investigated the levels of miR-9-1, miR-203-3p, miR-221-3p, miR-342-3p, miR-491-5p and miR-503-5p in 90 pairs of colon cancer and adjacent normal tissues, and explored the relationship between their expression and clinical outcome of colon cancer. Five miRNAs (miR-203-3p, miR-221-3p, miR-342-3p, miR-491-5p and miR-503-5p) were dysregulated in colon cancer tissue (P < 0.05). The levels of miR-503-5p in larger tumors (≥ 6 cm) were higher than those in smaller ones (< 6 cm) (P = 0.031), while the levels of miR-203-3p and miR-491-5p in patients aged 70 years and older were higher than those in patients aged younger than 70 years (P = 0.019 and 0.049, respectively). The high levels of miR-221-3p (HR = 2.416, 95% CI 1.314-4.445, P = 0.005), miR-342-3p (HR = 1.807, 95% CI 1.003-3.253, P = 0.049) and miR-491-5p (HR = 1.868, 95% CI 1.032-3.384, P = 0.039) were significantly associated with worse survival time. Moreover, combination analysis of miR-221-3p, miR-342-3p and miR-491-5p expression revealed that patients with 3 highly expressed miRNAs had lower survival rates compared with those with zero-to-two highly expressed miRNAs (HR = 2.100, 95% CI 1.157-3.813, P = 0.015), especially those with TNM stages I and II (HR = 4.204,95% CI 1.762-10.030, P = 0.001). Our results suggest that the three-miRNA signature may help doctors better predict prognosis and guide treatment decisions for colon cancer.