miR‐516a‐3p inhibits breast cancer cell growth and EMT by blocking the Pygo2/Wnt signalling pathway

miR‐516a‐3p has been reported to play a suppressive role in several types of human tumours. However, the expression level, biological function and fundamental mechanisms of miR‐516a‐3p in breast cancer remain unclear. In the present study, we found that miR‐516a‐3p expression was down‐regulated and Pygopus2 (Pygo2) expression was up‐regulated in human breast cancer tissues and cells. Through analysing the clinicopathological characteristics, we demonstrated that low miR‐516a‐3p expression or positive Pygo2 expression was a predictor of poor prognosis for patients with breast cancer. The results of a dual luciferase reporter assay and Western blot analysis indicated that Pygo2 was a target gene of miR‐516a‐3p. Moreover, overexpression of miR‐516a‐3p inhibited cell growth, migration and invasion as well as epithelial‐mesenchymal transition (EMT) of breast cancer cells, whereas reduced miR‐516a‐3p expression promoted breast cancer cell growth, migration, invasion and EMT. Furthermore, we showed that miR‐516a‐3p suppressed cell proliferation, metastasis and EMT of breast cancer cells by inhibiting Pygo2 expression. We confirmed that miR‐516a‐3p exerted an anti‐tumour effect by inhibiting the activation of the Wnt/β‐catenin pathway. Finally, xenograft tumour models were used to show that miR‐516a‐3p inhibited breast cancer cell growth and EMT via suppressing the Pygo2/Wnt signalling pathway. Taken together, these results show that miR‐516a‐3p inhibits breast cancer cell growth, metastasis and EMT by blocking the Pygo2/ Wnt/β‐catenin pathway.     

SIRT2, a direct target of miR‐212‐5p,suppresses the proliferation and metastasis of colorectal cancer cells

The aberrant expression of human sirtuin 2 (SIRT2) has been detected in various types of cancer; however, the biological roles, underlying mechanisms and clinical significance of SIRT2 dysregulation in human colorectal cancer (CRC) remain unclear. The results of this study demonstrate that compared with paired normal tissues, SIRT2 expression is significantly decreased in CRC tissues. SIRT2 loss has been correlated with clinicopathological characteristics, including distant metastasis, lymph node metastasis and American Joint Committee on Cancer (AJCC) stage; this loss serves as an independent factor that indicates a poor prognosis for patients with CRC. Further gain‐ and loss‐of‐function analyses have demonstrated that SIRT2 suppresses CRC cell proliferation and metastasis both in vivo and in vitro. Mechanistically, miR‐212‐5p was identified to directly target the SIRT2 3′‐untranslated region (3′‐UTR), leading to SIRT2 down‐regulation. The ectopic expression of SIRT2 reverses the effect of miR‐212‐5p overexpression on CRC cell colony formation, invasion, migration and proliferation. Clinically, an inverse correlation was found between miR‐212‐5p and SIRT2 expression. High miR‐212‐5p expression has been found to result in a poor prognosis and aggressive clinicopathological characteristics in patients with CRC. Taken together, these results suggest that SIRT2, targeted by miR‐212‐5p, acts as a tumour suppressor in CRC and that the miR‐212‐5p/SIRT2 axis is a promising prognostic factor and potential therapeutic target in CRC.     

COPB2 is up‐regulated in breast cancer and plays a vital role in the metastasis via N‐cadherin and Vimentin

Breast cancer (BC) is a common malignant tumour for the adult female and its relative incidence has increased continuously in recent years. The primary molecular mechanisms of breast tumourigenesis remain unclear. With the sequencing technology, we found that coatomer protein complex subunit beta 2 (COPB2) gene is overexpressed in breast cancer tissues. However, the biological function of COPB2 in BC has yet to be determined. This current research demonstrates, significant up‐regulation of COPB2 in tissues of breast cancer while comparing the adjacent normal tissue both invalidated cohort and TCGA cohort. Up‐regulated expression of COPB2 was correlated with lymph node metastasis (LNM) and oestrogen receptor (ER) in the TCGA cohort and a high level of COPB2 was associated with age and lymph node metastasis in the validated cohort. Besides, logistic analysis illustrated in BC patient COPB2 expression, tumour size, age, ER and disease stage were independent high‐risk factors of LNM. Loss of function experiments revealed that down‐regulation of COPB2 could inhibit capacities of proliferation and cell invasion in MDA‐MB‐231 and BT‐549 cell lines. Moreover, underexpression of COPB2 could decrease the EMT‐related protein N‐cadherin and vimentin which may lead to cell invasion. This current research provides new shreds of evidence that COPB2 overexpression shows significant character in the progression of breast cancer. To best of our knowledge, our findings indicated that COPB2 was vital oncogene which was associated with breast cancer.     

MicroRNA‐93‐5p expression in tumor tissue and its tumor suppressor function via targeting programmed death ligand‐1 in colorectal cancer

This work aimed to investigate miR‐93‐5p expression in tumor tissue and its in vitro effects in colorectal cancer (CRC) by targeting programmed death ligand‐1 (PD‐L1). MiR‐93‐5p and PD‐L1 expression was detected in CRC and adjacent normal tissues by quantitative real‐time polymerase chain reaction and immunohistochemistry. The correlation between miR‐93‐5p and PD‐L1 was validated by a dual‐luciferase reporter assay. HCT116 and SW480 cells were divided into blank, miR‐NC, miR‐93‐5p mimics, miR‐93‐5p inhibitor, PD‐L1 small interfering RNA (siRNA) and miR‐93‐5p inhibitor + PD‐L1 siRNA groups, and wound‐healing and transwell assays were performed to detect cell migration and invasion, respectively. Protein expression was measured by western blotting. The secretion of cytokines was detected in the CRC cell/T coculture models. MiR‐93‐5p was downregulated in CRC tissues with upregulated PD‐L1. In PD‐L1‐negative patients, miR‐93‐5p expression was increased compared with that in PD‐L1‐positive patients. MiR‐93‐5p and PD‐L1 expression levels were associated with the tumor differentiation, lymphatic metastasis, TNM, Duke's stage, and prognosis of CRC. PD‐L1 siRNA weakened the migration and invasion abilities via decreased expression of matrix metalloproteinase‐1 (MMP‐1), ‐2, and ‐9, and these effects were abolished by the miR‐93‐5p inhibitor. Additionally, anti‐PD‐L1 upregulated the expressions of interleukin‐2 (IL‐2), tumor necrosis factor‐α (TNF‐α), and interferon γ (IFN‐γ) in the coculture of T cells with CRC cells, but downregulated the expressions of IL‐1β, IL‐10, and TGF‐β. However, these changes were partially reversed by miR‐93‐5p inhibition. miR‐93‐5p is expected to be a novel target for CRC treatment since it decreases the migration and invasion, as well as the immune evasion, of CRC cells via targeting PD‐L1.     

MiR‐129‐5p inhibits glioma cell progression in vitro and in vivo by targeting TGIF2

This study purposed to explore the correlation between miR‐129‐5p and TGIF2 and their impacts on glioma cell progression. Differentially expressed miRNA was screened through microarray analysis. MiR‐129‐5p expression levels in glioma tissues and cells were measured by qRT‐PCR. CCK‐8 assay, flow cytometer, transwell assay and wound‐healing assay were employed to detect cell proliferation, apoptosis and cycle, invasiveness and migration, respectively. Dual‐luciferase reporting assay was performed to confirm the targeted relationship between miR‐129‐5p and TGIF2. The effects of TGIF2 expression on cell biological functions were also investigated using the indicated methods. Tumour xenograft was applied to explore the impact of miR‐129‐5p on tumorigenesis in vivo. MiR‐129‐5p expression was down‐regulated in both glioma tissues and glioma cells, while TGIF2 expression was aberrantly higher than normal level. Dual‐luciferase reporter assay validated the targeting relation between miR‐129‐5p and TGIF2. Overexpression of miR‐129‐5p or down‐regulation of TGIF2 inhibited the proliferation, invasion and migration capacity of glioma cells U87 and U251, and meanwhile blocked the cell cycle as well as induced cell apoptosis. MiR‐129‐5p overexpression repressed the tumour development in vivo. MiR‐129‐5p and TGIF2 had opposite biological functions in glioma cells. MiR‐129‐5p could inhibit glioma cell progression by targeting TGIF2, shining light for the development of target treatment for glioma.     

miR‐655 suppresses epithelial‐to‐mesenchymal transition by targeting Prrx1 in triple‐negative breast cancer

Triple‐negative breast cancer (TNBC) is a highly aggressive breast cancer subtype that lacks effective targeted therapies. The epithelial‐to‐mesenchymal transition (EMT) is a key contributor in the metastatic process. In this study, we found that miR‐655 was down‐regulated in TNBC, and its expression levels were associated with molecular‐based classification and lymph node metastasis in breast cancer. These findings led us to hypothesize that miR‐655 overexpression may inhibit EMT and its associated traits of TNBC. Ectopic expression of miR‐655 not only induced the up‐regulation of cytokeratin and decreased vimentin expression but also suppressed migration and invasion of mesenchymal‐like cancer cells accompanied by a morphological shift towards the epithelial phenotype. In addition, we found that miR‐655 was negatively correlated with Prrx1 in cell lines and clinical samples. Overexpression of miR‐655 significantly suppressed Prrx1, as demonstrated by Prrx1 3′‐untranslated region luciferase report assay. Our study demonstrated that miR‐655 inhibits the acquisition of the EMT phenotype in TNBC by down‐regulating Prrx1, thereby inhibiting cell migration and invasion during cancer progression.     

MiR‐671‐5p plays a promising role in restraining osteosarcoma cell characteristics through targeting TUFT1

The aim of our study was to explore the roles of miR‐671‐5p in mediating biological processes of osteosarcoma (OS) cells and clinical implications. On the basis of the OS samples acquired from the GEO database, the expression difference and overall survival analyses of miR‐671‐5p and TUFT1 were determined. The expression of MiR‐671‐5p was verified using OS cell lines. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide, wound‐healing, and Transwell assays were respectively carried out to probe whether miR‐671‐5p regulated OS cell vitality, migration, and invasion. The expression of miR‐671‐5p was downregulated in OS tissues and cell lines. High expression of MiR‐671‐5p blocked OS cell growth, migration, and invasion. TUFT1 was predicted and validated as the target of miR‐671‐5p in OS cells using in silico analysis and luciferase reporter assays. Forced expression of TUFT1 reversed the suppressive influence of miR‐671‐5p on cell viability, migration, and invasion of OS cells. Moreover, the low expression of miR‐671‐5p and the high expression of TUFT1 led to poor prognosis. Taken together, targeting miR‐671‐5p/TUFT1 may be a promising strategy for treating OS.     

miR‐515‐5p controls cancer cell migration through MARK4 regulation

Here, we show that miR‐515‐5p inhibits cancer cell migration and metastasis. RNA‐seq analyses of both oestrogen receptor receptor‐positive and receptor‐negative breast cancer cells overexpressing miR‐515‐5p reveal down‐regulation of NRAS, FZD4, CDC42BPA, PIK3C2B and MARK4 mRNAs. We demonstrate that miR‐515‐5p inhibits MARK4 directly 3′ UTR interaction and that MARK4 knock‐down mimics the effect of miR‐515‐5p on breast and lung cancer cell migration. MARK4 overexpression rescues the inhibitory effects of miR‐515‐5p, suggesting miR‐515‐5p mediates this process through MARK4 down‐regulation. Furthermore, miR‐515‐5p expression is reduced in metastases compared to primary tumours derived from both in vivo xenografts and samples from patients with breast cancer. Conversely, miR‐515‐5p overexpression prevents tumour cell dissemination in a mouse metastatic model. Moreover, high miR‐515‐5p and low MARK4 expression correlate with increased breast and lung cancer patients' survival, respectively. Taken together, these data demonstrate the importance of miR‐515‐5p/MARK4 regulation in cell migration and metastasis across two common cancers.     

Epigenetic silenced miR‐125a‐5p could be self‐activated through targeting Suv39H1 in gastric cancer

Emerging evidence suggests that microRNAs (miRNAs) serve an important role in tumorigenesis and development. Although the low expression of miR‐125a‐5p in gastric cancer has been reported, the underlying mechanism remains unknown. In the current study, the low expression of miR‐125a‐5p in gastric cancer was verified in paired cancer tissues and adjacent non‐tumour tissues. Furthermore, the GC islands in the miR‐125a‐5p region were hypermethylated in the tumour tissues. And the hypermethylation was negatively correlated with the miR‐125a‐5p expression. Target gene screening showed that the histone methyltransferase Suv39H1 was one of the potential target genes. In vitro studies showed that miR‐125a‐5p could directly suppress the Suv39H1 expression and decrease the H3K9me3 levels. On the other hand, the Suv39H1 could induce demethylation of miR‐125a‐5p, resulting in re‐activation of miR‐125a‐5p. What is more, overexpessing miR‐125a‐5p could also self‐activate the silenced miR‐125a‐5p in gastric cancer cells, which suppressed cell migration, invasion and proliferation in vitro and inhibited cancer progression in vivo. Thus, we uncovered here that the epigenetic silenced miR‐125a‐5p could be self‐activated through targeting Suv39H1 in gastric cancer, suggesting that miR‐125a‐5p might be not only the potential prognostic value as a tumour biomarker but also potential therapeutic targets in gastric cancer.     

MiR‐139‐5p inhibits the tumorigenesis and progression of oral squamous carcinoma cells by targeting HOXA9

Our study sought to clarify the effects of microRNA‐139‐5p (miR‐139‐5p) in the tumorigenesis and progression of oral squamous cell carcinoma (OSCC) by regulating HOXA9. MiR‐139‐5p and HOXA9 expression in OSCC tissues, tumour adjacent tissues, OSCC cells and normal cells were tested by qRT‐PCR. SAS and CAL‐27 cell lines were selected in among four OSCC cell lines and then transfected with miR‐139‐5p mimics, pEGFP‐HOXA9 and cotransfected with miR‐139‐5p mimics + pEGFP‐HOXA9. We used MTT, colony formation, transwell and wound healing assays to analyse cell viability, proliferation, invasion and migration. The target relationship between miR‐139‐5p and HOXA9 was verified by luciferase reporter assay and Western blot, respectively. MiR‐139‐5p was down‐regulated, whereas HOXA9 was up‐regulated in OSCC tissues and cells. The proliferation, invasion and migration ability of SAS and CAL‐27 cells in miR‐139‐5p mimics group were significantly weaker than those in the control group and the miR‐NC group (P < 0.01). MiR‐139‐5p can negatively regulate HOXA9. The proliferation, invasion and migration of SAS and CAL‐27 cells in the miR‐139‐5p mimics + pEGFP‐HOXA9 group were not significantly different from those in the blank control and negative control groups (P > 0.05). Our results indicated that miR‐139‐5p could directly inhibit HOXA9, which might be a potential mechanism in inhibiting the proliferation, invasiveness and migration of OSCC cells.     

MiR‐139‐5p,miR‐940 and miR‐193a‐5p inhibit the growth of hepatocellular carcinoma by targeting SPOCK1

The study was aimed to screen out miRNAs with differential expression in hepatocellular carcinoma (HCC), and to explore the influence of the expressions of these miRNAs and their target gene on HCC cell proliferation, invasion and apoptosis. MiRNAs with differential expression in HCC were screened out by microarray analysis. The common target gene of these miRNAs (miR‐139‐5p, miR‐940 and miR‐193a‐5p) was screened out by analysing the target genes profile (acquired from Targetscan) of the three miRNAs. Expression levels of miRNAs and SPOCK1 were determined by quantitative real time polymerase chain reaction (qRT‐PCR). The target relationships were verified by dual luciferase reporter gene assay and RNA pull‐down assay. Through 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide,thiazolyl blue tetrazolium bromide (MTT) and transwell assays and flow cytometry, HCC cell viability, invasion and apoptosis were determined. In vivo experiment was conducted in nude mice to investigate the influence of three miRNAs on tumour growth. Down‐regulation of miR‐139‐5p, miR‐940 and miR‐193a‐5p was found in HCC. Overexpression of these miRNAs suppressed HCC cell viability and invasion, promoted apoptosis and inhibited tumour growth. SPOCK1, the common target gene of miR‐139‐5p, miR‐940 and miR‐193a‐5p, was overexpressed in HCC. SPOCK1 overexpression promoted proliferation and invasion, and restrained apoptosis of HCC cells. MiR‐139‐5p, miR‐940 and miR‐193a‐5p inhibited HCC development through targeting SPOCK1.     

LncRNA MIR503HG inhibits cell migration and invasion via miR‐103/OLFM4 axis in triple negative breast cancer

Long non‐coding RNA MIR503 host gene (MIR503HG) is located on chromosome Xq26.3, and has been found to be deregulated in many types of human malignancy and function as tumour suppressor or promoter based on cancer types. The role of MIR503HG in breast cancer was still unknown. In our study, we found MIR503HG expression was significantly decreased in triple‐negative breast cancer tissues and cell lines. Furthermore, we observed low MIR503HG expression was correlated with late clinical stage, lymph node metastasis and distant metastasis. In the survival analysis, we observed that triple‐negative breast cancer patients with low MIR503HG expression had a statistically significant worse prognosis compared with those with high MIR503HG expression, and low MIR503HG expression was a poor independent prognostic factor for overall survival in triple‐negative breast cancer patients. The study in vitro suggested MIR503HG inhibits cell migration and invasion via miR‐103/OLFM4 axis in triple negative breast cancer. In conclusion, MIR503HG functions as a tumour suppressive long non‐coding RNA in triple negative breast cancer.     

Long non‐coding RNA F11‐AS1 inhibits HBV‐related hepatocellular carcinoma progression by regulating NR1I3 via binding to microRNA‐211‐5p

Long non‐coding RNAs (lncRNAs) could regulate growth and metastasis of hepatocellular carcinoma (HCC). In this study, we aimed to investigate the mechanism of lncRNA F11‐AS1 in hepatitis B virus (HBV)–related HCC. The relation of lncRNA F11‐AS1 expression in HBV‐related HCC tissues to prognosis was analysed in silico. Stably HBV‐expressing HepG2.2.15 cells were established to explore the regulation of lncRNA F11‐AS1 by HBx protein, as well as to study the effects of overexpressed lncRNA F11‐AS1 on proliferation, migration, invasion and apoptosis in vitro. Subsequently, the underlying interactions and roles of lncRNA F11‐AS1/miR‐211‐5p/NR1I3 axis in HBV‐related HCC were investigated. Additionally, the influence of lncRNA F11‐AS1 and miR‐211‐5p on tumour growth and metastasis capacity of HepG2.2.15 cells were studied on tumour‐bearing nude mice. Poor expression of lncRNA F11‐AS1 was correlated with poor prognosis in patients with HBV‐related HCC, and its down‐regulation was caused by the HBx protein. lncRNA F11‐AS1 was proved to up‐regulate the NR1I3 expression by binding to miR‐211‐5p. Overexpression of lncRNA F11‐AS1 reduced the proliferation, migration and invasion, yet induced apoptosis of HepG2.2.15 cells in vitro, which could be abolished by overexpression of miR‐211‐5p. Additionally, either lncRNA F11‐AS1 overexpression or miR‐211‐5p inhibition attenuated the tumour growth and metastasis capacity of HepG2.2.15 cells in vivo. Collectively, lncRNA F11‐AS1 acted as a modulator of miR‐211‐5p to positively regulate the expression of NR1I3, and the lncRNA F11‐AS1/miR‐211‐5p/NR1I3 axis participated in HBV‐related HCC progression via interference with the cellular physiology of HCC.     

The long non‐coding RNA‐ROR promotes osteosarcoma progression by targeting miR‐206

The long intergenic non‐protein coding RNA regulator of reprogramming (lncRNA‐ROR) has been reported to play crucial regulatory roles in the pathogenesis and progression of multiple cancers. However, whether ROR is associated with the initiation and development of osteosarcoma (OS) remains unclear. Here, we found that ROR expression level was significantly up‐regulated in OS tissue samples compared to adjacent normal tissues, and the elevated ROR was closely correlated with advanced tumour‐node‐metastasis (TNM) stage and lymph node metastasis and poor overall survival rate. Functional assays showed that ROR knockdown suppressed the OS cell proliferation, colony formation, migration and invasion in vitro, and retarded tumour growth in vivo. In addition, miR‐206 was verified to be a target miRNA of ROR using bioinformatics online program and luciferase report assay. miR‐206 inhibition partially rescued the inhibitory effects on OS cells induced by ROR knockdown. In conclusion, these results suggested that ROR function as an oncogene in OS by sponging miR‐206 and might be a potential therapeutic target for patients with OS.     

Up‐regulation of ZFAS1 indicates dismal prognosis for cholangiocarcinoma and promotes proliferation and metastasis by modulating USF1 via miR‐296‐5p

LncRNAs has been demonstrated to modulate neoplastic development by modulating downstream miRNAs and functional genes. In this study, we aimed to detect the interaction among lncRNA ZFAS1 miR‐296‐5p and USF1. We explored the proliferation, migration and invasion of cholangiocarcinoma. The differentially expressed ZFAS1 was discovered in both tissues and cell lines by qRT‐PCR. The targeting relationship between miR‐296‐5p and ZFAS1 or USF1 was validated by dual‐luciferase assay. The impact of ZFAS1 on CCA cell proliferation was observed by CCK‐8 assay. The protein expression of USF1 was determined by Western blot. The effects of ZFAS1, miR‐296‐5p and USF1 on tumour growth were further confirmed using xenograft model. LncRNA ZFAS1 expression was relatively up‐regulated in tumour tissues and cells while miR‐296‐5p was significantly down‐regulated. Knockdown of ZFAS1 significantly suppressed tumour proliferation, migration, invasion and USF1 expression. Overexpressed miR‐296‐5p suppressed cell proliferation and metastasis. Knockdown of USF1 inhibited cell proliferation and metastasis and xenograft tumour growth. In conclusion, ZFAS1 might promote cholangiocarcinoma proliferation and metastasis by modulating USF1 via miR‐296‐5p.     

LncRNA SNHG14 potentiates pancreatic cancer progression via modulation of annexin A2 expression by acting as a competing endogenous RNA for miR‐613

This study aimed to determine long non‐coding RNA (lncRNA) small nucleolar RNA host gene 14 (SNHG14) expression in pancreatic cancer and to explore the potential molecular actions of SNHG14 in mediating pancreatic cancer progression. Gene expression was detected by quantitative real‐time PCR. Cell proliferation, growth and invasion were detected by respective CCK‐8, colony formation, and transwell invasion assays. Protein levels were measured by Western blotting. Cell apoptosis and caspase‐3 activity were detected by flow cytometry and caspase‐3 activity assay. The link between miR‐613 and its targets was evaluated by luciferase reporter assay. In vivo tumour growth was evaluated using a xenograft model of nude mice. SNHG14 expression was up‐regulated in cancerous tissues from pancreatic cancer patients. High expression of SNHG14 was associated with poor tumour differentiation, advanced TNM stage and nodal metastasis. SNHG14 overexpression enhanced cell proliferative, growth and invasive abilities, and suppressed apoptotic rates and caspase‐3 activity in pancreatic cancer cells, while SNHG14 knockdown exerted opposite effects. Mechanistic studies revealed that miR‐613 was targeted by SNHG14, and Annexin A2 (ANXA2) was targeted and inversely regulated by miR‐613 in pancreatic cancer cells. In vivo studies showed that SNHG14 knockdown attenuated tumour growth. MiR‐613 was down‐regulated and ANXA2 was up‐regulated in the pancreatic cancer tissues, and SNHG14 expression levels were inversely correlated with miR‐613 expression levels and positively correlated with the ANXA2 mRNA expression levels. Collectively, our results suggest that SNHG14 potentiates pancreatic cancer progression through modulation of annexin A2 expression via acting as a competing endogenous RNA for miR‐613.     

MicroRNA‐301b‐3p contributes to tumour growth of human hepatocellular carcinoma by repressing vestigial like family member 4

MicroRNAs (miRNAs) are key regulators in the tumour growth and metastasis of human hepatocellular carcinoma (HCC). Increasing evidence suggests that miR‐301b‐3p functions as a driver in various types of human cancer. However, the expression pattern of miR‐301b‐3p and its functional role as well as underlying molecular mechanism in HCC remain poorly known. Our study found that miR‐301b‐3p expression was significantly up‐regulated in HCC tissues compared to adjacent non‐tumour tissues. Clinical association analysis revealed that the high level of miR‐301b‐3p closely correlated with large tumour size and advanced tumour‐node‐metastasis stages. Importantly, the high miR‐301b‐3p level predicted a prominent poorer overall survival of HCC patients. Knockdown of miR‐301b‐3p suppressed cell proliferation, led to cell cycle arrest at G2/M phase and induced apoptosis of Huh7 and Hep3B cells. Furthermore, miR‐301b‐3p knockdown suppressed tumour growth of HCC in mice. Mechanistically, miR‐301b‐3p directly bond to 3′UTR of vestigial like family member 4 (VGLL4) and negatively regulated its expression. The expression of VGLL4 mRNA was down‐regulated and inversely correlated with miR‐301b‐3p level in HCC tissues. Notably, VGLL4 knockdown markedly repressed cell proliferation, resulted in G2/M phase arrest and promoted apoptosis of HCC cells. Accordingly, VGLL4 silencing rescued miR‐301b‐3p knockdown attenuated HCC cell proliferation, cell cycle progression and apoptosis resistance. Collectively, our results suggest that miR‐301b‐3p is highly expressed in HCC. miR‐301b‐3p facilitates cell proliferation, promotes cell cycle progression and inhibits apoptosis of HCC cells by repressing VGLL4.     

MicroRNA‐425‐5p regulates chemoresistance in colorectal cancer cells via regulation of Programmed Cell Death 10

Acquired chemoresistance represents a major obstacle in cancer treatment, the underlying mechanism of which is complex and not well understood. MiR‐425‐5p has been reported to be implicated tumorigenesis in a few cancer types. However, its role in regulating chemoresistance has not been investigated in colorectal cancer (CRC) cells. Microarray analysis was performed in isogenic chemosensitive and chemoresistant HCT116 cell lines to identify differentially expressed miRNAs. miRNA quantitative real‐time PCR was used to detect miR‐425‐5p expression levels between drug resistant and parental cancer cells. MiR‐425‐5p mimic and inhibitor were transfected, followed by CellTiter‐Glo^® assay to examine drug sensitivity in these two cell lines. Western Blot and luciferase assay were performed to investigate the direct target of miR‐425‐5p. Xenograft mouse models were used to examine in vivo function of miR‐425‐5p. Our data showed that expression of miR‐425‐5p was significantly up‐regulated in HCT116‐R compared with parental HCT116 cells. Inhibition of miR‐425‐5p reversed chemoresistance in HCT116‐R cells. Programmed cell death 10 (PDCD10) is the direct target of miR‐425‐5p which is required for the regulatory role of miR‐425‐5p in chemoresistance. MiR‐425‐5p inhibitor sensitized HCT116‐R xenografts to chemo drugs in vivo. Our study demonstrated that miR‐425‐5p regulates chemoresistance of CRC cells by modulating PDCD10 expression level both in vitro and in vivo. MiR‐425‐5p may represent a new therapeutic target for the intervention of CRC.     

LncRNA MEG3 inhibits the progression of prostate cancer by modulating miR‐9‐5p/QKI‐5 axis

This study was designed to detecting the influences of lncRNA MEG3 in prostate cancer. Aberrant lncRNAs expression profiles of prostate cancer were screened by microarray analysis. The qRT‐PCR and Western blot were employed to investigating the expression levels of lncRNA MEG3, miR‐9‐5p and QKI‐5. The luciferase reporter assay was utilized to testifying the interactions relationship among these molecules. Applying CCK‐8 assay, wound healing assay, transwell assay and flow cytometry in turn, the cell proliferation, migration and invasion abilities as well as apoptosis were measured respectively. LncRNA MEG3 was a down‐regulated lncRNA in prostate cancer tissues and cells and could inhibit the expression of miR‐9‐5p, whereas miR‐9‐5p down‐regulated QKI‐5 expression. Overexpressed MEG3 and QKI‐5 could decrease the abilities of proliferation, migration and invasion in prostate cancer cells effectively and increased the apoptosis rate. On the contrary, miR‐9‐5p mimics presented an opposite tendency in prostate cancer cells. Furthermore, MEG3 inhibited tumour growth and up‐regulated expression of QKI‐5 in vivo. LncRNA MEG3 was a down‐regulated lncRNA in prostate cancer and impacted the abilities of cell proliferation, migration and invasion, and cell apoptosis rate, this regulation relied on regulating miR‐9‐5p and its targeting gene QKI‐5.