Molecular mechanism of miR-29a inhibiting malignant phenotypes in prostate cancer cells

AIM:To investigate the biological functions of microRNA-29a (miR-29a) in prostate cancer and the molecular mechanism of miR-29a over-expression inhibiting malignant phenotypes of prostate cancer cells. METHODS:The levels of miR-29a expression in the prostate cancer tissues and cells were detected and analyzed using gene microarray and bioinformatics. The expression levels of miR-29a and lysine (K)-specific demethylase 4B (KDM4B) mRNA in prostate cancer tissues, paracarcinomatous tissues, 4 prostate cancer cell lines (PC3, DU145, LNCaP and ArCaP) and normal prostate epithelial cell line (RWPE-1) were measured by real-time PCR. PC3, DU145, LNCaP and ArCaP cells were transfected with pGenesil-1-miR-29a plasmid using transient transfection. The cell viability, colony formation rate and apoptotic rate were analyzed by MTT assay, colony formation assay and flow cytometry with Annexin V-FITC/PI staining, respectively. The protein expression of KDM4B was determined by Western blot. RESULTS:The results of gene microarray and bioinformatic analysis indicated that differential expression of miR-29a was found in the prostate cancer tissues and the paracarcinomatous tissues. The levels of miR-29a in the prostate cancer tissues and prostate cancer cells were significantly decreased, while the mRNA levels of KDM4B were notably increased compared with the paracarcinomatous tissues and RWPE-1 cells, respectively (P<0.05). Compared with negative control (pGenesil-1) group, the cell viability and colony formation rate were significantly decreased, the apoptotic rate was significantly increased, and the protein expression of KDM4B was notably inhibited in the prostate cancer cells with miR-29a over-expression (P<0.05). The cell viability was significantly enhanced, and the apoptosis was significantly inhibited in the prostate cancer cells with KDM4B over-expression (P<0.05). CONCLUSION:Low expression of miR-29a was found in the prostate cancer tissues and cells. miR-29a over-expression inhibits the growth of prostate cancer cells and induces apoptosis. The mechanism may be associated with inhibiting the protein expression of KDM4B.     

miR-496 over-expression inhibits growth and metastasis in colon cancer cells

AIM: To investigate the effect of miR-496 over-expression on the growth and metastasis of colon cancer cells and its molecular mechanism.METHODS: The proteins interacting with miR-496 were screened by bioinformatic method. The levels of miR-496, CTNNB1 mRNA and β-catenin protein in colon cancer cell lines, HT29, HCT116 and SW480, and normal colonic epithelial cell line NCM460 were detected by real-time PCR and Western blot. HT29, HCT116 and SW480 cells were transfected with miR-496 mimics using Lipofectamine 2000 and named as HT29-miR-496 mimics, HCT116-miR-496 mimics and SW480-miR-496 mimics cells, respectively, and the cells transfected with the scramble served as negative control. The cell viability, lactate dehydrogenase (LDH) leakage, and colony formation and metastatic abilities were determined by MTT assay, LDH assay, colony formation assay and Transwell method, respectively. The promoter activity of miR-496 was measured using luciferase reporter gene assay. The protein levels of β-catenin, eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), p-4E-BP1, low-density lipoprotein receptor-related protein 6(LRP6), p-LRP6, MMP-7, MMP-9, MMP-13 and TIMP-2 were monitored by Western blot.RESULTS: Endogenous miR-406 interacted with β-catenin was found in the colon cancer cells. Low miR-496 expression in the HT29, HCT116 and SW480 cells and high miR-496 expression in NCM460 cells were detected. In contrast, high β-catenin expression was found in the HT29, HCT116 and SW480 cells and low β-catenin expression was observed in the NCM460 cells. Compared with control group, the cell viability, colony formation rate and the number of metastatic cells remarkably decreased in the HT29-miR-496 mimics, HCT116-miR-496 mimics and SW480-miR-496 mimic cells (P<0.05). The promoter activity of miR-496 was significantly increased in colon cancer cells transfected with miR-496 mimics, and was 1.75, 2.04 and 1.61 times as high as control group. miR-496 over-expression inhibited β-catenin levels, and p-4E-BP1 and p-LRP6 protein levels were also reduced. siRNA- or over-expressed miR-496-mediated β-catenin down-regulation inhibited MMP-7 and MMP-9 expression, but promoted TIMP-2 expression.CONCLUSION: The expression level of miR-496 in the colon cancer cells is low, but in the normal colonic epithelial cells is high. miR-496 over-expression inhibits the protein levels of MMP-7 and MMP-9, and promotes the protein expression of TIMP-2 via inhibiting Wnt/β-catenin pathway, thus suppressing malignant phenotype in the colon cancer cells.     

Molecular mechanism of miR-1246 enhancing radiosensitivity of cervical cancer cells

AIM: To investigate the molecular mechanism of microRNA-1246(miR-1246) enhancing radiosensitivity of cervical cancer cells. METHODS: Cervical cancer lines HeLa, CaSki, C33A and SiHa were transfected with miR-1246 mimic and negative control mimic (NC-mimic) using Lipofectamine 2000 kit, and the expression level of miR-1246 in cervical cancer tissue, normal tissue, cervical cancer cell lines and endometrial epithelium cell line ESC was detected by real-time PCR. The transfected cells were exposed to X-ray radiation. The cell viability and migration rate were measured respectively by MTT assay and Transwell method. The protein levels of γH2AX, ATM, p-ATM and p-p53 were monitored by immunofluorescence and Western blot. RESUITS: Higher miR-1246 level was found in normal tissue and ESC cells, while lower miR-1246 level was found in HeLa, SiHa, C33A and Caski cells and cervical cancer tissues. The expression level of miR-1246 in the cells transfected with miR-1246 mimic was significantly higher than that in the cells transfected with NC-mimic (P<0.05). The cell viability and migration rate of the cervical cancer cells with miR-1246 over-expression were notably lower than those of the cells transfected with NC-mimic (P<0.05) under the same conditions. The results of immunofluorescence indicated that the protein expression level of γH2AX significantly increased in the cervical cancer cells with miR-1246 over-expression exposed to radiation compared with the negative control (P<0.05). The protein expression level of γH2AX was significantly increased in the cervical cancer cells with miR-1246 over-expression, while the protein levels of p-ATM and p-p53 were significantly decreased as compared with the negative control group (P<0.05). CONCLUSION: miR-1246 is highly expressed in normal tissue and normal endometrial epithelial cells, while is low expressed in the cervical cancer tissues or cells. miR-1246 over-expression inhibits growth and migration, and significantly enhances radiosensitivity of cervical cancer cells. The molecular mechanism is possibly related to inhibiting ATM pathway and DNA damage repair.     

MicroRNA-330 inhibits growth and migration of gastric cancer cells by directly targeting EGR-2

AIM:To explore the function and significance of microRNA-330 (miR-330) in the development of gastric cancer. METHODS:Forty-eight cases of gastric cancer tissues and paired adjacent tissues were collected in Department of Oncology, Affiliated Hospital of Gansu University of Chinese Medicine, and the expression levels of miR-330 were detected by RT-qPCR. The expression levels of miR-330 in the gastric cancer cells and human gastric epithelial GES-1 cells were evaluated by RT-qPCR. The viability, colony formation and migration of gastric cancer cells after transfected with miR-330 inhibitor or miR-330 mimic were analyzed by CCK-8 assay, colony formation assay and Transwell assay, respectively. Furthermore, miR-330 target gene was predicted by miRanda target gene prediction database. RESULTS:miR-330 expression was down-regulated both in gastric cancer tissues and gastric cancer cells (P<0.05). The expression levels of miR-330 were negatively associated with the tumor size, lymph metastasis, pathological grade stage and T stage (P<0.05). The viability, colony formation and migration of gastric cancer cells were significantly increased after transfected with miR-330 inhibitor (P<0.05). However, the viability, colony formation and migration of gastric cancer cells were significantly decreased after transfected with miR-330 mimic (P<0.05). Furthermore, EGR-2 was the direct target gene of miR-330. CONCLUSION:miR-330 suppresses gastric cancer cell growth and migration, and the mechanism may be related to its direct target gene EGR-2, suggesting that miR-330 may be used as a potential new target for diagnosis and targeted therapy for gastric cancer.     

Effect of inhibiting lncRNA LINC01503 on viability,migration and invasion of lung cancer cells by targeted regulation of miR-335-5p

AIM To investigate the effects of long non-coding RNA (lncRNA) LINC01503 on the viability, migration and invasion of lung cancer cells and its mechanism. METHODS Human lung carcinoma H1299 cells were divided into si-NC group (transfected with si-NC), si-LINC01503 group (transfected with si-LINC01503), pcDNA group (transfected with pcDNA), pcDNA-LINC01503 group (transfected with pcDNA-LINC01503), miR-NC group (transfected with miR-NC), miR-335-5p group (transfected with miR-335-5p mimics), si-LINC01503+anti-miR-NC group (co-transfected with si-LINC01503 and anti-miR-NC), si-LINC01503+anti-miR-335-5p group (co-transfected with si-LINC01503 and anti-miR-335-5p), miR-NC+WT-LINC01503 group (co-transfected with miR-NC and WT-LINC01503), miR-NC+MUT-LINC01503 group (co-transfected with miR-NC and MUT-LINC01503), miR-335-5p+WT-LINC01503 group (co-transfected with miR-335-5p and WT-LINC01503) and miR-335-5p+MUT-LINC01503 group (co-transfected with miR-335-5p and MUT-LINC01503). The expression of miR-335-5p and LINC01503 was detected by RT-qPCR. Western blot was used to detect protein expression. MTT assay was used to detect cell viability. Transwell assay was used to detect the migration and invasion abilities. Dual-luciferase reporter assay was used to confirm the targeted relationship between LINC01503 and miR-335-5p. RESULTS Compared with normal tissues, the expression of LINC01503 was significantly increased in the lung cancer tissues, and the expression of miR-335-5p was significantly decreased (P<0.05). Compared with stage I/II , the expression level of LINC01503 in the lung cancer tissues of stage III/IV was significantly increased, and the expression of miR-335-5p was significantly decreased (P<0.05). The patients with high expression of LINC01503 had lower short-term survival rates than those with low expression of LINC01503 (P<0.05). Compared with normal human bronchial epithelial cell line BEAS-2B, the expression of miR-335-5p in lung cancer cell lines H1299, A549 and SPC-A-1 were significantly decreased, and the expression of LINC01503 was significantly increased (P<0.05). Over-expression of miR-335-5p and inhibition of LINC01503 expression inhibited the viability, migration and invasion of H1299 cells, and inhibited the protein expression of cyclin D1, matrix metalloproteinase-2 （MMP-2） and MMP-9 (P<0.05). LINC01503 targeted and regulated miR-335-5p expression, and interfering with miR-335-5p expression reversed the inhibitory effect of inhibiting LINC01503 expression on the viability, migration and invasion of H1299 cells. CONCLUSION Inhibition of lncRNA LINC01503 inhibits the viability, migration and invasion of lung cancer cells. The mechanism may be related to the targeted regulation of miR-335-5p.     

Regulatory effects of miR-195 on biological behaviors of lung cancer A549 cells

AIM: To investigate the regulatory effects of microRNA (miR)-195 on the biological behaviors, such as viability, apoptosis and migration, of lung cancer A549 cells, and to explore the related mechanisms. METHODS: After miR-195 mimics were transfected into the A549 cells, the cell viability, cell cycle distribution and apoptosis were measured by CCK-8 assay and flow cytometry. Transwell assay was used to detect cell migration ability. Furthermore, the protein levels of cyclin D1, CDK2, Bcl-2 and p-Rb/Rb were determined by Western blot. Dual-luciferase reporter assay was used to screen and identify the possible target genes of miR-195. RESULTS: Over-expression of miR-195 in the A549 cells inhibited the cell viability and induced cell cycle arrest, accompanied with the decrease in the cell migration ability and the increase in the apoptotic rate (P<0.05). Furthermore, the protein levels of cyclin D1, CDK2, Bcl-2 and p-Rb were significantly decreased (P<0.05). Dual-luciferase reporter assay demonstrated that MYB was a potential target gene of miR-195. Over-expression of MYB in the A549 cells partially reversed the effects of miR-195 on the cell viability, apoptosis and migration. CONCLUSION: miR-195 inhibits lung cancer A549 cell growth and migration, and promotes cell apoptosis by targeting MYB gene.     

Mechanism of microRNA-138-5p inhibiting proliferation,migration and invasion of lung cancer cells

AIM: To investigate the mechanism of microRNA-138-5p (miR-138-5p) inhibiting the proliferation, migration and invasion abilities of lung cancer cells.METHODS: The lung cancer A549 and H460 cells were transfected with miR-NC (control group) or miR-138-5p (experimental group). The bioinformatic analysis was performed to predict the target genes of miR-138-5p.The expression levels of miR-138-5p, forkhead box protein C1 (FOXC1) mRNA and vimentin mRNA were detected by RT-qPCR. The protein expression of FOXC1, vimentin, E-cadherin, N-cadherin and β-catenin was determined by Western blot. MTS method and colony formation assay were used to detect cell viability and proliferation ability. Wound healing assay and Transwell assay were used to detect cell migration and invasion ability.RESULTS: Over-expression of miR-138-5p significantly reduced the expression of FOXC1 and vimentin at mRNA and protein levels (P<0.05). The expression of E-cadherin and β-catenin were up-regulated and the expression of N-cadherin was down-regulated. The proliferation, migration and invasion abilities of the lung cancer cells were inhibited by the over-expression of miR-138-5p.CONCLUSION: miR-138-5p inhibits the proliferation, migration and invasion abilities of lung cancer cells by targeting FOXC1 and vimentin. It may be a potential target for lung cancer gene therapy.     

miR-137 regulates invasion,migration and apoptosis of breast cancer MDA-MB-231 cells through TWIST1

AIM: To investigate the effect and its molecular mechanism of microRNA-137(miR-137) on the invasion, migration abilities and apoptosis of breast cancer cells. METHODS: miR-137 mimimics were transfected into the breast cancer MDA-MB-231 cells. The expression of miR-137 was detected by RT-qPCR. Apoptosis was analyzed by flow cytometry. The invasion and migration abilities were detected by Transwell assays. The protein levels of matrix metalloproteinase 9 (MMP-9), cleaved caspase-3 (C-caspase-3) and Bax were determined by Western blot. Bioinformatics software was used to predict that TWIST1 might be the target gene of miR-137 and then it was conformed by luciferase reporter gene identification. The effect of miR-137 mimics on TWIST1 protein expression was evaluated by Western blot. TWIST1 over-expression vector and miR-137 mimics were co-transfected into the MDA-MB-231 cells, and then the apoptosis, invasion, migration abilities and the protein levels of MMP-9, C-caspase-3 and Bax were determined. RESULTS: In the miR-137 mimics transfected MDA-MB-231 cells, the expression level of miR-137 and the apoptosis rate were increased, the cell invasion and migration abilities were decreased, the protein levels of C-caspase-3 and Bax were increased, the protein expression of MMP-9 was decreased (P<0.05). In addition, the target regulation of TWIST1 by miR-137 was identified by luciferase reporter assay. Moreover, the expression of TWIST1 in the MDA-MB-231 cells was inhibited by miR-137 mimics. Compared with the MDA-MB-231 cells co-transfected with negative control vector and miR-137 mimics, the protein expression levels of TWIST1 and MMP-9 in the MDA-MB-231 cells co-transfected with TWIST1 over-expression vector and miR-137 mimics were increased, the protein levels of C-caspase-3 and Bax and the apoptosis rate were decreased, the cell invasion and migration abilities were increased. CONCLUSION: miR-137 inhibits the invasion, migration abilities and induces apoptosis of breast cancer cells through targeting TWIST1.     

miR-556-3p regulates viability,migration and invasion of endometrial cancer cells by targeting SASH1

AIM To investigate whether microRNA-556-3p （miR-556-3p） regulates the viability, migration and invasion of endometrial cancer cells by targeting SASH1 gene. METHODS The expression of miR-556-3p, and the mRNA and protein levels of SASH1 in endometrial cancer tissues were detected by RT-qPCR and Western blot. Anti-miR-556-3p or pcDNA-SASH1 was transfected into endometrial cancer Ishikawa cells. The cell viability was detected by MTT assay, the migration and invasion abilities of the cells were detected by Transwell chamber method, and the protein expression levels of cyclin D1, p21, matrix metalloproteinase-2 （MMP-2） and MMP-9 were detected by Western blot. StarBase prediction and dual-luciferase reporter experiments were used to analyze the targeting relationship between miR-556-3p and SASH1. Anti-miR-556-3p and si-SASH1 were co-transfected into the Ishikawa cells, and their effects on cell viability, migration and invasion were examined by the methods described above. RESULTS Compared with adjacent tissues, the expression of miR-556-3p in endometrial cancer tissues was increased significantly, and the expression of SASH1 at mRNA and protein levels was decreased significantly （P<0.05）. Inhibition of miR-556-3p expression or induction of SASH1 over-expression obviously reduced the viability of Ishikawa cells, the number of migratory cells, the number of invasive cells and the protein levels of cyclin D1, MMP-2 and MMP-9, and dramatically increased the protein level of p21 （P<0.05）. miR-556-3p targeted SASH1 and negatively regulated its expression. Knock-down of SASH1 expression reversed the inhibitory effect of miR-556-3p expression inhibition on the viability, migration and invasion of Ishikawa cells. CONCLUSION Inhibition of miR-556-3p expression suppresses the viability, migration and invasion of endometrial cancer cells. The mechanism is related to the regulation of its target gene SASH1.     

Hsa-miR-218 inhibits growth of cervical cancer HeLa cells by targeting to LASP1

AIM: To study the effect of hsa-miR-218 on cervical cancer HeLa cell growth and the underlying molecular mechanism.METHODS: The lentivirus expression vector pmiR-218 targeting to hsa-miR-218 was constructed. pmiR-218 was transfected into HeLa cells. The number of viable HeLa cells was counted by the method of Trypan blue exclusion. The inhibitory rate of cell activity was detected by WST-8 assay. The expression of LIM and SH3 protein 1(LASP1) at mRNA and protein levels was determined by real-time PCR and Western blot. The interaction between miR-218 and LASP1 was examined using a luciferase reporter assay.RESULTS: The lentivirus expression vector pmiR-218 targeting to hsa-miR-218 was constructed successfully and confirmed by DNA sequencing. Over-expression of miR-218 inhibited the activity of HeLa cells with the inhibitory rates of 15%, 26% and 65% at 24 h, 48 h and 72 h, respectively. The difference between transfection group and blank control/negative control group was statistically significant. The luciferase activity was reduced when co-transfection with miR-218 mimics and LASP1-3,UTR plasmid. The relative expression of miR-218 was increased after transfection with pmiR-218. Over-expression of miR-218 down-regulated the LASP1 expression at mRNA and protein levels by 25% and 75% respectively. Compared with blank control group and negative control group, the difference was statistically significant(P<0.05).CONCLUSION: pmiR-218 effectively inhibits the growth of HeLa cells in a time-dependent manner. miR-218 targets to the 3,UTR of LASP1, thus down-regulating the expression of LASP1 in HeLa cells.     

miR-125a-5p reverses cisplatin resistance of non-small-cell lung cancer A549/DDP cells by targeting LIMK1

AIM:To explore the effect of microRNA-125a-5p (miR-125a-5p) on cisplatin (DDP) resistance of non-small-cell lung cancer A549/DDP cells and its related mechanisms. METHODS:The expression levels of miR-125a-5p and LIM kinase 1 (LIMK1) in non-small-cell lung cancer tissues, A549 cells and A549/DDP cells were detected by RT-qPCR. The A549/DDP cell viability, apoptotic rate and expression of drug resistance-related proteins after over-expression or knockdown of miR-125a-5p and/or LIMK1 expression were detected by MTT assay, flow cytometry and Western blot, respectively. The targeting relationship between miR-125a-5p and LIMK1 was verified by TargetScan online prediction and dual-luciferase reporter system. The cell viability, apoptotic rate and expression of drug resistance-related proteins after co-expression of miR-125a-5p and LIMK1 were also determined. RESULTS:The expression level of miR-125a-5p was down-regulated and LIMK1 expression was up-regulated in non-small-cell lung cancer tissues and cell lines (P<0.05). The results of dual-luciferase assay indicated that miR-125a-5p negatively regulated the expression of LIMK1. The expression of drug resistance-related proteins and the viability of A549/DDP cells were inhibited after over-expression of miR-125a-5p or knockdown of LIMK1, while the apoptosis was enhanced. Over-expression of LIMK1 attenuated the inhibitory effect of miR-125a-5p on A549/DDP cell viability and drug resistance-related protein expression (P<0.05). CONCLUSION:miR-125a-5p reverses the resistance of A549/DDP cells to DDP by inhibiting the expression of LIMK1 and drug resistance-related proteins.     

Value of endonuclease domain containing 1 in progression of prostate cancer

AIM: To analyze the difference of endonuclease domain containing 1 (ENDOD1) expression between benign prostatic hyperplasia (BPH) tissues and prostate cancer (PCa) tissues and to investigate the effect of ENDOD1 on the biological function of human prostate cancer cells. METHODS: The BPH samples (n=20) and PCa samples (n=21) were processed and analyzed according to the instruction of immunohistochemical (IHC) staining. The mRNA and protein levels of ENDOD1 in the normal prostate epithelial cells and prostate cancer cells were evaluated by RT-qPCR and Western blot, respectively. The recombinant plasmids pCMV-N-Flag-ENDOD1 was constructed and was transfected into the human prostate cancer cells. The proliferation, apoptosis, migration and invasion abilities of the prostate cancer cells were evaluated by MTT assay, flow cytometry, Transwell migration and Matrigel invasion assays, respectively. RESULTS: The analysis of variance of the immunoreactivity score showed that PCa tissues with high Gleason score displayed significantly lower ENDOD1expression than that with low Gleason score and BPH (P<0.05). The expression of ENDOD1 at mRNA and protein levels in PC3 cells and DU145 cells was significantly lower than that in the LNCap cells (P<0.05). The proliferation of DU145 transfected with ENDOD1 was inhibited. The flow cytometry indicated that ENDOD1 over-expression in the DU145 cells resulted in a notable increase in G₀/G₁ phase arrest (P<0.05), but the apoptotic rates showed no statistical difference. The results of Transwell assay showed that migration and invasion abilities of the cells were also inhibited after transfection with over-expressing ENDOD1 plasmid (P<0.05). CONCLUSION: The expression of ENDOD1 significantly decreased in prostate cancer with high Gleaon score. Meanwhile, the ENDOD1 is specifically down-regulated in androgen independent prostate cancer (AIPC) cell lines. Over-expression of ENDOD1 remarkably inhibits the proliferation, migration and invasion abilities of AIPC.     

Clinical significance of miRNA-326 expression in gastric cancer and effect of up-regulation of its expression on viability and apoptosis of gastric cancer cells

AIM: To investigate the clinical significance of microRNA-326 (miRNA-326) expression in gastric carcinoma and the effect of up-regulation of its expression on the viability and apoptosis of gastric cancer cells. METHODS: The expression of miRNA-326 in 55 tissue samples of gastric cancer was detected by RT-qPCR, and the relationship between the expression and the clinicopathological features was analyzed. The expression of miRNA-326 in gastric cancer BGC-823 cells was detected by RT-qPCR. The BGC-823 cells were transfected by liposome method, and randomly divided into normal control group (untransfected), mimic-NC group (transfected with negative control mimic) and miRNA-326 mimic group (transfected with miRNA-326 mimic). After up-regulation of miRNA-326 expression, the cell viability was measured by CCK-8 assay, and the apoptosis of the cells was analyzed by flow cytometry. The protein levels of matrix metalloprotein 9 (MMP-9), p21, cyclin D1, Bcl-2 and cleaved caspase-3 were determined by Western blot, and the mRNA expression of cyclin D1 was detected by RT-qPCR. Whether CCND1 (the gene of cyclin D1) was the target gene of miRNA-326 was evaluated by dual-luciferase reporter assay. RESULTS: The expression of miRNA-326 in the gastric cancer tissues was significantly lower than that in the adjacent tissues (P<0.05). The miRNA-326 expression had a significant correlation with the tumor size, lymph node metastasis, differentiation, and clinical stages (P<0.05), but it had no correlation with the age and sex of the patients. Moreover, the expression of miRNA-326 was also closely related to the survival rate of the patients (P<0.05). The expression of miRNA-326 in the BGC-823 cells was significantly lower than that in the normal gastric mucosa GES-1 cells (P<0.05). Compared with normal control group, the expression of miRNA-326 in mimic-NC group did not change significantly, while that in miRNA-326 mimic group was increased significantly (P<0.05). Compared with normal control group, the cell viability in miRNA-326 mimic group was significantly decreased, and the apoptosis was increased (P<0.05). In addition, compared with normal control group, the protein levels of MMP-9, cyclin D1 and Bcl-2, and the mRNA expression of cyclin D1 in miRNA-326 mimic group were decreased, while the protein levels of p21 and cleaved caspase-3 were increased (P<0.05). However, no significant difference of above protein and mRNA levels between mimic-NC group and normal control group was observed. Compared with mimic-NC+miR-326 mimic group, the activity of luciferase in the cells transfected with pmiR-CCND1-WT plasmid was significantly decreased (P<0.05), but that in the cells transfected with pmiR-CCND1-Mut plasmid did not change significantly. CONCLUSION: The expression level of miRNA-326 in gastric cancer tissues is low, and it may promote cell viability and inhibit cell apoptosis by targeting CCND1.     

miR-15a-5p inhibits proliferation and migration of human hepatocellular carcinoma SMMC-7721 cells

AIM: To observe the influence of high expression of miR-15a-5p on the proliferation and migration of human hepatocellular carcinoma SMMC-7721 cells.METHODS: The miR-15a-5p oligonucleotide, which was reconstructed with additional restriction sites of EcoR Ⅰ and Hind Ⅲ, was chemically synthesized and confirmed by sequencing. The miR-15a-5p eukaryotic expression system was constructed by pcDNA6.2-GW/Em-GFP-pre-miR-15a-5p plasmid. The miR-15a-5p was transfected into the SMMC-7721 cells transiently by plasmid, and quantified by quantitative real-time PCR at the mRNA level. The cell viability was measured by CCK-8 assay, and the living cell counting was performed by the method of Trypan blue exclusion. The migration ability of the SMMC-7721 cells with high expression of miR-15a-5p was detected by wound healing test.RESULTS: The sequence of miR-15a-5p oligonucleotide 100% matched the designed sequence. Compared with control group, the miR-15a-5p expression was increased significantly (P<0.05). The viability, the living cell number and the migration ability of the SMMC-7721 cells were decreased in high expression of miR-15a-5p group with statistically significant difference (P<0.05).CONCLUSION: The abilities of proliferation and migration in human hepatocellular carcinoma SMMC-7721 cells are decreased by high expression of miR-15a-5p.     

Effect of miR-375 on viability,cell cycle and apoptosis of colon cancer HCT116 cells

AIM: To investigate the effect of microRNA-375 (miR-375) on the viability, cell cycle and apoptosis of HCT116 cells.METHODS: The expression of miR-375 in different colorectal cancer cell lines was detected by real-time PCR. The miR-375 mimics was transfected into HCT116 cells by Lipofectamine^TM 2000. The mRNA expression of miR-375 and AEG-1 was detected by real-time PCR. The HCT116 cell viability was detected by MTT assay. The changes of apoptosis and cell cycle distribution were analyzed by flow cytometry.RESULTS: Real-time PCR showed that miR-375 expression was the lowest in HCT116 among 4 colorectal cancer cell lines. The expression level of miR-375 significantly increased in miR-375 mimics group compared with that in the negative control group. The high expression level of miR-375 significantly inhibited the mRNA expression of AEG-1. After transfection with miR-375 mimics, the cell viability was inhibited, the apoptotic rate was increased, the proportion of G₁-stage cells was increased, and the proportion of S-stage cells was decreased.CONCLUSION: miR-375 inhibits the viability, mediates the cell cycle arrest and promotes the apoptosis of colon cancer HCT116 cells. miR-375 may act as a tumor suppressor in colorectal cancer by inhibiting AEG-1.     

miR-485-5p inhibits viability and migration and invasion abilities of hepatocellular carcinoma Hep3B cells by targeting SOX5

AIM: To investigate the effects of microRNA-485-5p (miR-485-5p) on the viability, migration and invasion abilities of hepatocellular carcinoma cells and the underlying mechanism. METHODS: The expression levels of sex determining region Y-box 5 (SOX5) mRNA and miR-485-5p in the hepatocellular carcinoma Hep3B cells were detected by RT-qPCR with normal hepatocyte THLE-3 as control. Western blot was used to measure the expression levels of SOX5, proliferating cell nuclear antigen (PCNA), Ki67, cyclin D1 and matrix metalloproteinase-2 (MMP-2). The viability of Hep3B cells was measured by MTT assay. The migration and invasion abilities of the Hep3B cells were detected by Transwell assay. Dual-luciferase reporter assay system was applied to verify the relationship between miR-485-5p and SOX5. RESULTS: Compared with the control cells, the expression level of miR-485-5p was decreased in hepatocellular carcinoma cells Hep3B, Huh7 and HCCLM3 (P<0.05), while the expression of SOX5 at mRNA and protein levels were significantly increased (P<0.05). Over-expression of miR-485-5p inhibited the viability, migration and invasion of Hep3B cells. miR-485-5p targeted the 3′-UTR of SOX5 and negatively regulated the expression of SOX5. Knocking-down of SOX5 expression inhibited the viability, migration and invasion of Hep3B cells. Over-expression of SOX5 partially reversed the inhibitory effect of miR-485-5p over-expression on the viability, migration and invasion of Hep3B cells. CONCLUSION: miR-485-5p inhibits the viability, migration and invasion of Hep3B cells by targeting SOX5 gene. miR-485-5p is a potential molecular target for hepatocellular carcinoma.     

Effects of down-regulation of AEG-1 expression on cell cycle and invasion of human cervical carcinoma cells

AIM: To investigate the effects of down-regulation of astrocyte elevated gene-1 (AEG-1) expression on cell cycle and invasion of human cervical carcinoma SiHa cells.METHODS: The protein expression of AEG-1 was detected by Western blotting in normal cervical tissues, cervical squamous cell carcinoma tissues, HeLa cells, SiHa cells and CaSki cells. Control siRNA or AEG-1 siRNA was transfected into SiHa cells, and the protein expression of AEG-1 in SiHa cells was detected by Western blotting. The changes of cell cycle distribution and cell invasion were determined by flow cytometry and Boyden chamber, respectively. The protein levels of cyclin D1, cyclin-dependent kinase 2(CDK2) and matrix metalloproteinase-9 (MMP-9) were analyzed by Western blotting.RESULTS: The protein expression of AEG-1 in cervical squamous cell carcinoma tissues was significantly higher than that in normal cervical tissues (P<0.05). Meanwhile, the protein expression of AEG-1 in the 3 cervical carcinoma cell lines was obviously higher than that in normal cervical tissues, in which SiHa cells displayed the highest AEG-1 protein level (P<0.05). In addition, AEG-1 siRNA effectively down-regulated the protein expression of AEG-1 in SiHa cells, which led to increase the percentage at G0/G1 phase and reduced the invasion of SiHa cells. Furthermore, the protein levels of cyclin D1, CDK2 and MMP-9 in AEG-1 siRNA group were markedly lower than those in non-treatment group and control siRNA group (P<0.05).CONCLUSION: Over-expression of AEG-1 may be closely associated with the occurrence and development of cervical carcinoma, and the AEG-1 down-regulation-mediated cell cycle arrest and attenuation of invasion may be tightly related to the down-regulations of cyclin D1, CDK2 and MMP-9 at protein levels.     

Expression and significance of miR-193b in cervical cancer

AIM: To investigate the expression of microRNA-193b(miR-193b) in the cervical tissues, and further to explore the effect of silencing miR-193b on diamminedichloroplatinum(DDP)-treated HeLa cell viability. METHODS: The expression levels of miR-193b in different cervical tissues were examined by qPCR. After transfection of miR-193b-inhibitor, the cell migration was determined by Transwell assay, the sensitivity of HeLa cells to DDP was measured by MTT assay, the protein levels of phosphate and tension homology deleted on chromsome ten(PTEN), protein kinase B(Akt), p-Akt and p-glycoprotein(P-gp) were determined by Western blot. RESULTS: The mRNA level of miR-193b was significantly increased in the cervical cancer tissues compared with normal cervical tissues(P<0.05). Knockdown of miR-193b obviously inhibited migration and enhanced sensitivity to DDP of HeLa cells(P<0.05). Additionally, after transfection of miR-193b-inhibitor, the expression of PTEN was increased, whereas the protein levels of p-Akt and P-gp were decreased(P<0.05). CONCLUSION: miR-193b is highly expressed in the cervical cancer tissues. Inhibition of miR-193b augments the sensitivity to DDP of HeLa cells, at least in part, through PTEN-PI3K/Akt signaling pathway.     

MicroRNA-200a affects malignant biological behaviors of breast cancer cells by inhibiting epithelial-mesenchymal transition

AIM: To investigate the effect of microRNA-200a (miR-200a) on the malignant biological beha-viors of breast cancer cells and its regulatory mechanism. METHODS: The expression of miR-200a in human breast can-cer cell lines MDA-MB-231, MDA-MB-468 and MCF-7, and normal human mammary epithelial cell line MCF-10A was detected by RT-qPCR. CCK-8 assay was used to detect the viability of MDA-MB-231 cells after transfection with miR-200a mimic or miR-200a inhibitor. Flow cytometry method and Transwell assay were used to detect the apoptosis and invasive ability of MDA-MB-231 cells after transfection with miR-200a mimic or miR-200a inhibitor. The expression of SIP1, E-cadherin, N-cadherin, Snail, Twist, ZEB1 and ZEB2 at mRNA and protein levels was determined by RT-qPCR and Western blot. RESULTS: Compared with MCF-10A cells, the lowest expression of miR-200a was observed in the MDA-MB-231 cells (P<0.05). Over-expression of miR-200a attenuated the viability of MDA-MB-231 cells (P<0.05), increased apoptosis (P<0.05) and decreased the invasion ability (P<0.05). The expression of SIP1, N-cadherin, Snail, Twist, ZEB1 and ZEB2 at mRNA and protein levels was also significantly down-regulated, while the mRNA and protein expression of E-cadherin was significantly increased (P<0.05). Transfection with miR-200a inhibitor reversed the above results. CONCLUSION: Up-regulation of miR-200a inhibits the viability and invasion ability of MDA-MB-231 cells and promotes the apoptosis of MDA-MB-231 cells. miR-200a may regulate the biological behaviors of breast cancer by inhibiting epithelial-mesenchymal transition.