miR-142-5p suppresses proliferation and promotes apoptosis of human osteosarcoma cell line, HOS, by targeting PLA2G16 through the ERK1/2 signaling pathway

METTL3 stabilizes HDAC5 mRNA in an m6A-dependent manner to facilitate malignant proliferation of osteosarcoma cells

Osteosarcoma (OS) is a prevalent primary bone sarcoma. Methyltransferase-like 3 (METTL3) is dysregulated in human malignancies. This study explored the mechanism of METTL3 in OS cell proliferation. Our results demonstrated that METTL3 was highly expressed in OS, and correlated with the tumor size, clinical stage, and distant metastasis of OS patients. Higher METTL3 expression indicated poorer prognosis. METTL3 silencing inhibited the malignant proliferation of OS cells, while METTL3 overexpression led to an opposite trend. METTL3 upregulated histone deacetylase 5 (HDAC5) expression in OS cells by increasing the m⁶A level. HDAC5 reduced the enrichment of H3K9/K14ac on miR-142 promoter, thus suppressing miR-142-5p expression and upregulating armadillo-repeat-containing 8 (ARMC8) level. HDAC5 overexpression or miR-142-5p silencing attenuated the inhibitory effect of METTL3 silencing on OS cell proliferation. Xenograft tumor experiment in nude mice confirmed that METTL3 silencing repressed OS cell proliferation in vivo via the HDAC5/miR-142-5p/ARMC8 axis. Collectively, METTL3-mediated m⁶A modification facilitated OS cell proliferation via the HDAC5/miR-142-5p/ARMC8 axis.

miRNome Profiling Detects miR-101-3p and miR-142-5p as Putative Blood Biomarkers of Frailty Syndrome

Frailty is an aging-related pathology, defined as a state of increased vulnerability to stressors, leading to a limited capacity to meet homeostatic demands. Extracellular microRNAs (miRNAs) were proposed as potential biomarkers of various disease conditions, including age-related pathologies. The primary objective of this study was to identify blood miRNAs that could serve as potential biomarkers and candidate mechanisms of frailty. Using the Fried index, we enrolled 22 robust and 19 frail subjects. Blood and urine samples were analysed for several biochemical parameters. We observed that sTNF-R was robustly upregulated in the frail group, indicating the presence of an inflammatory state. Further, by RNA-seq, we profiled 2654 mature miRNAs in the whole blood of the two groups. Expression levels of selected differentially expressed miRNAs were validated by qPCR, and target prediction analyses were performed for the dysregulated miRNAs. We identified 2 miRNAs able to significantly differentiate frail patients from robust subjects. Both miR-101-3p and miR-142-5p were found to be downregulated in the frail vs. robust group. Finally, using bioinformatics targets prediction tools, we explored the potential molecular mechanisms and cellular pathways regulated by the two miRNAs and potentially involved in frailty.

A novel lncRNA ROPM-mediated lipid metabolism governs breast cancer stem cell properties

Background

Cancer stem cells (CSCs) are considered as the major cause to tumor initiation, recurrence, metastasis, and drug resistance, driving poor clinical outcomes in patients. Long noncoding RNAs (lncRNAs) have emerged as crucial regulators in cancer development and progression. However, limited lncRNAs involved in CSCs have been reported.

Methods

The novel lncROPM (a regulator of phospholipid metabolism) in breast CSCs (BCSCs) was identified by microarray and validated by qRT-PCR in BCSCs from breast cancer cells and tissues. The clinical significance of lncROPM was evaluated in two breast cancer cohorts and TANRIC database (TCGA-BRCA, RNAseq data). Gain- and loss-of-function assays were performed to examine the role of lncROPM on BCSCs both in vitro and in vivo. The regulatory mechanism of lncROPM was investigated by bioinformatics, RNA FISH, RNA pull-down, luciferase reporter assay, and actinomycin D treatment. PLA2G16-mediated phospholipid metabolism was determined by UHPLC-QTOFMS system. Cells’ chemosensitivity was assessed by CCK8 assay.

Results

LncROPM is highly expressed in BCSCs. The enhanced lncROPM exists in clinic breast tumors and other solid tumors and positively correlates with malignant grade/stage and poor prognosis in breast cancer patients. Gain- and loss-of-function studies show that lncROPM is required for the maintenance of BCSCs properties both in vitro and in vivo. Mechanistically, lncROPM regulates PLA2G16 expression by directly binding to 3'-UTR of PLA2G16 to increase the mRNA stability. The increased PLA2G16 significantly promotes phospholipid metabolism and the production of free fatty acid, especially arachidonic acid in BCSCs, thereby activating PI3K/AKT, Wnt/β-catenin, and Hippo/YAP signaling, thus eventually involving in the maintenance of BCSCs stemness. Importantly, lncROPM and PLA2G16 notably contribute to BCSCs chemo-resistance. Administration of BCSCs using clinic therapeutic drugs such as doxorubicin, cisplatin, or tamoxifen combined with Giripladib (an inhibitor of cytoplasmic phospholipase A2) can efficiently eliminate BCSCs and tumorigenesis.

Conclusions

Our study highlights that lncROPM and its target PLA2G16 play crucial roles in sustaining BCSC properties and may serve as a biomarker for BCSCs or other cancer stem cells. Targeting lncROPM-PLA2G16 signaling axis may be a novel therapeutic strategy for patients with breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-021-01194-z.

Doxorubicin-induced novel circRNA_0004674 facilitates osteosarcoma progression and chemoresistance by upregulating MCL1 through miR-142-5p

Accumulating evidence has shown that circular RNA (circRNA) dysregulation is involved in various types of cancer, including osteosarcoma (OS). Nevertheless, the role and mechanism of circRNAs in OS progression and chemoresistance remain elusive. We found that a novel doxorubicin-induced circular RNA, hsa_circ_0004674, screened by whole total transcriptome RNA sequencing in our previous study, was upregulated in OS chemoresistant cell lines and tissues and also connected with patients’ poor prognosis. Circ_0004674 knockdown remarkably suppressed OS cell chemoresistance, proliferation, migration, invasion, OS tumor growth, and enhanced cell cycle arrest and apoptosis in vitro and in vivo through control the expression of the antiapoptotic protein MCL1, a member of the Bcl-2 gene family. Further online bioinformatics analysis revealed that miR-142-5p had potential binding sites that can bind circ_0004674 and the 3′UTR of MCL1 mRNA. Moreover, the expression and function of miR-142-5p were conversely correlated with circ_0004674 in vitro. RIP, pull-down, luciferase assay, and RNA FISH demonstrated that circ_0004674 could compete with MCL1 for miR-142-5p binding to counteract miR-142-5p-mediated repression of MCL1 at the post-transcriptional level. To sum up, our study sheds light on the critical role of the oncogenic circ_0004674/miR-142-5p/MCL1 axis in OS progression and chemoresistance, providing a novel potential target for OS therapy.

Prognostic value of miR-142 in solid tumors: a meta-analysis

Several studies on the prognostic value of microRNA 142 (miR-142) in solid tumors have reported conflicting results. Therefore, the aim of this meta-analysis was to evaluate the relationship between the miR-142 and prognosis in solid tumors. A comprehensive search for relevant studies was conducted until 10 November 2020. Studies that investigated the prognostic significance of the miR-142 in solid tumors were included. The hazard ratio and 95% confidence interval were calculated using a random-effects model. All data analyses were performed using the STATA 12.0 software (Stata Corporation, College Station, TX, U.S.A.). Twenty articles involving 2451 participants were included in the meta-analysis. The results showed that high miR-142 expression was a better predictor of overall survival (OS) (HR = 0.66, 95% CI: 0.47–0.93) and disease-free/progression-free/recurrence-free survival (DFS/PFS/RFS) (HR = 0.71, 95% CI: 0.55–0.91) compared with low miR-142 expression. MiR-142 can be used as an effective prognostic marker for patients with solid tumors. Future large prospective studies are warranted to further confirm the present findings.

miR-142-5p promotes renal cell tumorigenesis by targeting TFAP2B

The transcription factor AP-2 β (TFAP2B) serves an important role in kidney development. MicroRNAs (miRNAs) regulate carcinogenic pathways and have gained increasing attention owing to their association with human clear cell renal cell carcinoma (ccRCC) tumorigenesis. However, whether miRNAs could affect renal cell tumorigenesis by regulating TFAP2B expression has not been identified. The aim of this study was to investigate the effects of miRNA on TFAP2B and its potential role in cell growth, invasion and migration. PCR, western blot and dual luciferase reporter assays were performed to analyze the effects of miR-142-5p on TFAP2B. Furthermore, MTT, flow cytometry, wound healing and Transwell migration assays were used to analyze the effect of miR-142-5p on cell proliferation and migration. The results demonstrated that miR-142-5p targeted TFAP2B and downregulated the expression of TFAP2B at the mRNA and protein levels, promoting cell proliferation and migration in two ccRCC cell lines, 786-O and A-498. This phenomenon supported the theory that miR-142-5p may function as an oncogene in ccRCC. The potential clinical significance of miR-142-5p as a biomarker and a therapeutic target provides rationale for further investigation into miR-142-5p-mediated molecular pathways and how these may be associated with ccRCC development.

MicroRNAs as regulators of ERK/MAPK pathway: A comprehensive review

The ERK/MAPK cascade is one the four distinctive MAPK cascades which transmit extracellular signals to intracellular targets. This cascade has an important role in the regulation of several fundamental processes such as proliferation, differentiation and cell response to diverse extrinsic stresses. Moreover, several studies have shown participation of this cascade in the pathogenesis of cancer. Recent investigations have unraveled interaction between microRNAs (miRNAs) and ERK/MAPK cascade. These transcripts reside in both upstream and downstream of this cascade, regulating or being regulated by ERK/MAPK proteins. In the current review, we summarize the role of miRNAs in the regulation of ERK/MAPK and their contribution in the pathogenesis of human disorders with particular focus on cancers.

Antibacterial peptides inhibit MC3T3-E1 cells apoptosis induced by TNF-α through p38 MAPK pathway

Background

Antimicrobial peptides (AMP), as a small molecular polypeptide with a broad antibacterial spectrum and high efficiency, have attracted more and more attention. Few pieces of research on the effect of the antimicrobial peptide on osteoblast under inflammatory conditions have so far been reported. The main aim of this work was to investigate the antiapoptosis effect of the antimicrobial peptide on MC3T3-E1 cells induced by TNF-α and its related mechanism.

Methods

Rat MC3T3-E1 cells were co-cultured with different concentrations of antibacterial peptide DP7 and TNF-α.MTS assay, cell scratch test, alkaline phosphatase activity, and alizarin red staining assay were used to determine osteoblast viability in this experiment. Annexin V-FITC/PI double staining cells and flow cytometry were used to analyze apoptosis and Western blot assay detection to show mitogen-activated protein kinase (MAPK) protein expression in rat MC3T3-E1 cells. Then, Realtime polymerase chain reaction (PCR) was used to examine the caspase-3 gene expression. Also, ELISA detection was used to clarify the anti-apoptotic effect of the p38 MAPK inhibitor, SB203580, on cells’ apoptosis.

Results

Antimicrobial peptide could promote the proliferation, migration, and osteogenic ability of MC3T3-E1 cells induced by TNF-α, but inhibit cell apoptosis rate (P<0.05), and the effect was concentration-dependent. Western blot results showed after TNF-αtreatment, the expression of p-p38 MAPK in the MC3T3-E1 cells increased after TNF-α and antimicrobial peptide cotreatment, TNF-α induced p-p38 MAPK phosphorylation was inhibited, and the difference was statistically significant (P<0.05). Realtime PCR results showed that the gene expression of caspase-3 mRNA was up-regulated after TNF-α treatment, while their expression was down-regulated after cultured with TNF-α and antimicrobial peptide. Elisa's analysis showed that cell apoptosis increased after TNF-α treatment alone, and cell apoptosis was reduced to the normal levels when combined with antimicrobial peptide, and cell apoptosis induced by TNF-α was partially abolished when combined with SB203580.

Conclusions

Antimicrobial peptide DP7 could inhibit MC3T3-E1 cells apoptosis induced by TNF-α, and the effect was concentration-dependent. The antiapoptosis activation of the antimicrobial peptide on MC3TE-E1 cells may be related to the inhibition of the p38 MAPK pathway.

Long non‑coding RNA NNT‑AS1 knockdown represses the progression of gastric cancer via modulating the miR‑142‑5p/SOX4/Wnt/β‑catenin signaling pathway

Patients with advanced gastric cancer (GC) have a poor prognosis with a median overall survival of 10–12 months. Long non-coding RNA nicotinamide nucleotide transhydrogenase-antisense RNA1 (NNT-AS1) and sex-determining region Y-related high mobility group box 4 (SOX4) have been reported to be associated with the progression of various types of cancer; however, the regulatory mechanism between NNT-AS1 and SOX4 in GC is not completely understood. Reverse transcription-quantitative PCR was used to detect the expression levels of NNT-AS1, microRNA (miR)-142-5p and SOX4. Western blotting was performed to assess the protein expression levels of SOX4, β-catenin, c-Myc, Bcl-2 and E-cadherin. The proliferation, apoptosis, migration and invasion of GC cells were determined using MTT, flow cytometry and Transwell assays. The relationship between miR-142-5p and NNT-AS1 or SOX4 was investigated using a dual-luciferase reporter assay. NNT-AS1 and SOX4 were upregulated, whereas miR-142-5p was downregulated in GC tissues and cells compared with normal tissues and cells. Both NNT-AS1 and SOX4 knockdown inhibited GC cell proliferation, migration and invasion, and enhanced GC cell apoptosis. Moreover, the results indicated that NNT-AS1 modulated SOX4 expression by sponging miR-142-5p. In addition, SOX4 overexpression reversed NNT-AS1 knockdown-mediated effects on GC cell proliferation, apoptosis, migration and invasion. NNT-AS1 knockdown blocked the Wnt/β-catenin signaling pathway via the miR-142-5p/SOX4 axis. Collectively, the present study indicated that NNT-AS1 knockdown decreased GC cell proliferation, migration and invasion, and induced GC cell apoptosis by regulating the miR-142-5p/SOX4/Wnt/β-catenin signaling pathway axis.

Long Non-Coding RNA FEZF1-AS1 Modulates CXCR4 to Promote Cell Proliferation, Warburg Effect and Suppress Cell Apoptosis in Osteosarcoma by Sponging miR-144

BACKGROUND

Osteosarcoma (OS) is a common bone tumor among children, adolescents, and young adults. Long non-coding RNA (lncRNA) FEZF1 antisense RNA 1 (FEZF1-AS1) has been reported as an oncogene in diverse tumors including colorectal cancer, pancreatic cancer and hepatocellular carcinoma, as well as in osteosarcoma. This study focused on the functions and mechanism of lncRNA FEZF1-AS1 in osteosarcoma.

METHODS

The levels of FEZF1-AS1, microRNA miR-144 and CXC motif chemokine receptor 4 (CXCR4) in OS tissues and cells (Saos-2 and HOS) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot assay. The interactions between miR-144 and FEZF1-AS1 or CXCR4 were predicted by DIANA tools online database. Then, the dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to validate the interactions. Moreover, the cell viability and apoptotic rate in transferred Saos-2 and HOS cells were assessed via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry, respectively. The levels of glucose and lactate productions were measured by glucose uptake and lactate production assay. In addition, the protein levels of Warburg-effect-related protein hexokinase 2 (HK2) and apoptosis-related proteins Bcl-2 or Bax in transferred Saos-2 and HOS cells were detected via Western blot assay.

RESULTS

The levels of FEZF1-AS1 and CXCR4 were strikingly up-regulated, and miR-144 was notably down-regulated in OS tissues and cells. DIANA tools online database exhibited that miR-144 was a direct target of FEZF1-AS1 and CXCR4 was a direct target of miR-144. Then the interactions were validated by dual-luciferase reporter assay and RIP assay. Functionally, FEZF1-AS1 silencing or miR-144 overexpression inhibited cell viability, the glucose and lactate productions and promoted cell apoptosis in Saos-2 and HOS cells. Furthermore, miR-144 inhibitor mitigated the inhibitory effects on cell viability, the glucose and lactate productions and the promoted effect on cell apoptosis rate in Saos-2 and HOS cells induced by FEZF1-AS1 depletion. Mechanistically, FEZF1-AS1 regulated CXCR4 in Saos-2 and HOS cells by sponging miR-144.

CONCLUSION

We verified that FEZF1-AS1, CXCR4 were up-regulated, and miR-144 was downregulated in OS tissues and cells. Furthermore, FEZF1-AS1 promoted cell proliferation, Warburg effect and suppressed cell apoptosis in osteosarcoma via miR-144/CXCR4 axis, this novel pathway may provide a basis for the further study of osteosarcoma.

Sulforaphane reduces intracellular survival of Staphylococcus aureus in macrophages through inhibition of JNK and p38 MAPK‑induced inflammation

Macrophages are active contributors to the innate immune defense system. As macrophage activation is clearly affected by the surrounding microenvironment, the present study investigated the effect of sulforaphane (SFN) on the bactericidal activity of macrophages and the underlying molecular mechanisms involved in this process. Human THP-1-derived macrophages, primary human peripheral blood mononuclear cell-derived macrophages, and primary mouse bone marrow derived-macrophages (BMDMs) pretreated with SFN or DMSO were utilized in a model of Staphylococcus aureus infection. The results suggested that SFN pretreatment of macrophages effectively repressed the intracellular survival of S. aureus through modulation of p38/JNK signaling and decreased S. aureus-induced caspases-3/7-dependent cell apoptosis, potentially through downregulation of microRNA (miR)-142-5p and miR-146a-5p. As SFN is a well-known activator of nuclear factor erythroid 2-related factor 2 (Nrf2), Nrf2^−/− BMDMs were used to demonstrate that the SFN-mediated inhibitory effect was independent of Nrf2. Nevertheless, an increase in intracellular bacterial survival in Nrf2-deficient macrophages was observed. In addition, SFN pretreatment suppressed S. aureus-induced transcriptional expression of genes coding for the proinflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α), as well as for the M1 markers C-C motif chemokine receptor 7, IL-23 and inducible nitric oxide synthase (iNOS). Western blot analysis indicated that S. aureus challenge activated p38 mitogen-activated protein kinase (MAPK) (p38) and c-Jun N-terminal kinase (JNK) MAPK signaling pathways, while SFN pretreatment prevented p38 and JNK phosphorylation. Pretreatment with 2 specific inhibitors of p38 and JNK, SB203580 and SP600125, respectively, resulted in a decrease in S. aureus-induced proinflammatory gene expression levels compared with those observed in the SFN-pretreated macrophages. Furthermore, THP-1-derived macrophages pretreated with SB203580 or SP600125 prior to bacterial infection exhibited a significant inhibition in intracellular S. aureus survival. In conclusion, we hypothesize that concomitant targeting of the p38/JNK-inflammatory response and the S. aureus-induced apoptosis with SFN may be a promising therapeutic approach in S. aureus infection.

Disruption of Cancer Metabolic SREBP1/miR-142-5p Suppresses Epithelial-Mesenchymal Transition and Stemness in Esophageal Carcinoma

: Elevated activity of sterol regulatory element-binding protein 1 (SREBP1) has been implicated in the tumorigenesis of different cancer types. However, the functional roles of SREBP1 in esophageal cancer are not well appreciated. Here, we aimed to investigate the therapeutic potential of SREBP1 and associated signaling in esophageal cancer. Our initial bioinformatics analyses showed that SREBP1 expression was overexpressed in esophageal tumors and correlated with a significantly lower overall survival rate in patients. Additionally, tumor suppressor miR-142-5p was predicted to target SREBP1/ZEB1 and a lower miR-142-5p was correlated with poor prognosis. We then performed in vitro experiments and showed that overexpressing SREBP1 in OE33 cell line led to increased abilities of colony formation, migration, and invasion; the opposite was observed in SREBP1-silenced OE21cells and SREBP1-silencing was accompanied by the reduced mesenchymal markers, including vimentin (Vim) and ZEB1, while E-cadherin and tumor suppressor miR-142-5p were increased. Subsequently, we first demonstrated that both SREBP1 and ZEB1 were potential targets of miR-142-5p, followed by the examination of the regulatory circuit of miR-142-5p and SREBP1/ZEB1. We observed that increased miR-142-5p level led to the reduced tumorigenic properties, such as migration and tumor sphere formation, and both observations were accompanied by the reduction of ZEB1 and SREBP1, and increase of E-cadherin. We then explored the potential therapeutic agent targeting SREBP1-associated signaling by testing fatostatin (4-hydroxytamoxifen, an active metabolite of tamoxifen). We found that fatostatin suppressed the cell viability of OE21 and OE33 cells and tumor spheres. Interestingly, fatostatin treatment reduced CD133+ population in both OE21 and OE33 cells in concert of increased miR-142-5p level. Finally, we evaluated the efficacy of fatostatin using a xenograft mouse model. Mice treated with fatostatin showed a significantly lower tumor burden and better survival rate as compared to their control counterparts. The treatment of fatostatin resulted in the reduced staining of SREBP1, ZEB1, and Vim, while E-cadherin and miR-142-5p were increased. In summary, we showed that increased SREBP1 and reduced miR-142-5p were associated with increased tumorigenic properties of esophageal cancer cells and poor prognosis. Preclinical tests showed that suppression of SREBP1 using fatostatin led to the reduced malignant phenotype of esophageal cancer via the reduction of EMT markers and increased tumor suppressor, miR-142-5p. Further investigation is warranted for the clinical use of fatostatin for the treatment of esophageal malignancy.

The Computational Analysis Conducted on miRNA Target Sites in Association with SNPs at 3'UTR of ADHD-implicated Genes

Background: Attention-deficit/hyperactivity disorder (ADHD) is a frequent chronic neuropsychiatric disorder in which different factors including environmental, genetic, and epigenetic factors play an important role in its pathogenesis. One of the effective epigenetic factors is recognized as MicroRNAs (miRNAs). On the other hand, it has been indicated that the single nucleotide polymorphism (SNPs) present within 3'UTR (3' untranslated region) of mRNAs can influence the regulation of miRNA-mediated gene and susceptibility to a diversity of human diseases.

Methods: The purpose of this study was to analyze the SNPs within the 3'UTR of miRNA target genes associated with ADHD . 3'UTR genetic variants were identified in all genes associated with ADHD using DisGeNET, dbGaP, Ovid, DAVID, Web of knowledge, and SNPs databases. miRNA's target prediction databases were applied in order to predict the miRNA binding sites. 124 SNPs with MAF>0.05 were identified located in the binding site of the miRNA of 35 genes amongst 51 genes associated with ADHD.

Results: Bioinformatics analysis predicted 81 MRE (miRNA recognition elements)-creating SNPs, 101 MRE-breaking SNPs, 61 MRE-enhancing SNPs, and finally predicted 41 MRE-decreasing SNPs in the 3'UTR of ADHD-implicated genes. These candidate SNPs within these genes miRNA binding sites can alter the miRNAs binding, and consequently, lead to mRNA gene regulation.

Conclusion: Therefore, these miRNA and MRE-SNPs may play important roles in ADHD, and because of that, they would be valuable for further investigation in the field of functional verification.

LncRNA TTN-AS1 promotes migration, invasion, and epithelial mesenchymal transition of lung adenocarcinoma via sponging miR-142-5p to regulate CDK5

Emerging evidence suggests that long noncoding RNA (lncRNA) plays pivotal roles in regulating various biological process in human cancers. Titin-antisense RNA1 (TTN-AS1) has been regarded as a tumor promoting lncRNA in numerous cancers. However, the clinical significance and biological function of TTN-AS1 in lung adenocarcinoma (LUAD) remain unclear. In the present study, we revealed that the expression of TTN-AS1 was upregulated in LUAD tissues and cell lines. High TTN-AS1 expression was associated with TNM stage and lymph node metastasis of LUAD patients. In addition, high expression of TTN-AS1 was correlated with poor postoperative prognosis of LUAD patients. Knockdown of TTN-AS1 significantly inhibited the growth, proliferation, migration, and invasion ability of LUAD cells in vitro. Then, by using bioinformation analysis and luciferase reporter experiment, we identified that TTN-AS1 could function as a competing endogenous RNA (ceRNA) by sponging miR-142-5p to regulate the expression of cyclin-dependent kinase 5 (CDK5) in LUAD. Since CDK5 is a key regulator in the process of epithelial mesenchymal transition (EMT), we detected the expression of EMT-related proteins, consequently, EMT was suppressed by knockdown of TTN-AS1 while this phenomenon was rescued by miR-142-5p inhibitor. Taken above, our study revealed that TTN-AS1 played an important role in LUAD progression. TTN-AS1/miR-142-5p/CDK5 regulatory axis may serve as a novel therapeutic target in the treatment of LUAD.

miR-937 regulates the proliferation and apoptosis via targeting APAF1 in breast cancer

Background: Previous research had shown that an imbalance in cell proliferation and apoptosis is a vital mechanism for tumorigenesis and cancer progression that may directly influence biological behaviors of cancer. microRNAs are associated with the occurrence and development of tumors. This study aimed to explore the influence of miR-937 on breast cancer regulation of APAF1 expression. Methods: Cancer Genome Altas microarray analysis (fold change > 2, p<0.05) was used to verify differentially expressed microRNAs and RT-qPCR was used to detect miR-937 mRNA level in breast cancer. Cell viability and proliferation were measured using CCK8 and colony formation assays, respectively, after the miR-937 mimics/inhibitors and their negative control were transfected into MCF7 cells. The variations in cell cycle and apoptosis were examined using flow cytometry. DAVID database was used to perform GO enrichment analysis. We use dual luciferase report system to detect the effect of miR-937 on the transcriptional activity of APAF1. APAF1 protein level was determined by Western blot assay. Results: miR-937 was up-regulated in breast cancer cell lines and high miR-937 expression is associated with a poorer survival rate in cancer patients. miR-937 overexpression promoted the viability, down-regulated the G1 phase ratios and increased the ability of colony formation in breast cancer cells. miR-937 inhibition inhibited the viability and the ability of colony formation, promoted the apoptosis and up-regulated the G1 phase ratios. Our results showed that miR-937 targeted bind to the APAF1-3'UTR. APAF1 overexpression inhibited the viability and the ability of colony formation, promoted the apoptosis and up-regulated the G1 phase ratios. After cells were co-transfection miR-937 mimics and APAF1, cell apoptosis level was increased. Conclusion: APAF1 up-regulation or APAF1 down-regulation in breast cancer may regulate cell proliferation and apoptosis.