Gene microarray analysis of ovarian serous cystadenocarcinoma-related genes based on TCGA

AIM: To detect the differentially expressed genes associated with ovarian serous cystadenocarcinoma (OV) by microarray and to analyze the participated signaling pathway. METHODS: We analyzed 16 datasets of Affymetrix GeneChip Human Exon 1.0 ST Arrays from The Cancer Genome Atlas (TCGA), including 8 OV and 8 normal ovary samples. The function of differential genes was determined by pathway and gene ontology (GO) analysis. The probable functions of the key genes were predicted according to intergenic signal transduction network. RESULTS: The 1 144 genes were identified as distinctively expressed in OV (P<0.05), 747 of which were up-regulated and 397 were down-regulated. The GO analysis results showed that the altered genes were involved in 362 up-regulated and 160 down-regulated significant functions (P<0.05) related to cell cycle, DNA replication, cell proliferation, cell apoptosis, cell adhesion, etc. The pathways of the different genes were involved in the 59 enrichment-related pathways (P<0.05), 45 of which were up-regulated and 14 were down-regulated. Among the 59 pathways, cell cycle, P53 signaling pathway, DNA replication, pathways in cancer, PI3K-Akt signaling pathway, ECM-receptor signaling pathway, cell adhesion molecules and cell apoptosis were related to tumor genesis, development and metastasis. As a result, 229 genes with significant functions and pathways in GO and pathway analysis were selected to construct signal transduction network (Signal-Net), 4 of which, CDK1, PLK1, MCM3 and PGK1, were found to play key roles in OV signal regulation network. CONCLUSION: The OV shows abundant differentially expressed genes that play key roles in cancer-related signal pathways.     

Up-regulation of microRNA-187* inhibits proliferation of human colon cancer cell line HCT116

AIM:To investigate the expression of microRNA-187* (miR-187*) in human colon cancer cell lines and normal colon tissues, and to determine the effects of miR-187* up-regulation on the proliferation and cell cycle of human colon cancer cell line HCT116. METHODS:The expression profiling of miRNAs in 3 colorectal adenocarcinoma samples and their matched normal tissue samples was performed using miRNA microarray chip. Total RNA was isolated from 8 colon cancer cell lines and 10 normal colon tissues. The miR-187* level was detected by Taqman real-time RT-PCR. B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1), the possible target of miR-187*, was also detected. Synthetic miR-187* mimics were transfected into HCT116 cell line by LipofectamineTM 2000. The mRNA expression of miR-187* and BMI-1 in HCT116 cell line was measured by real-time RT-PCR. Cell growth and cell cycle were assayed by MTS method and flow cytometry. RESULTS:miR-187* was found to be differentially expressed between colorectal adenocarcinoma and normal tissues. The expression of miR-187* in 8 colon cancer cell lines was down-regulated, while BMI-1 mRNA was up-regulated. Compared with blank control group, miR-187* expression was remarkably increased after transfection with miR-187* mimics, and ectopic expression of miR-187* significantly inhibited the mRNA expression of BMI-1. The cell growth was inhibited in miR-187* mimics group, and proliferating cell nuclear antigen (PCNA) mRNA expression was decreased. The cells at G2/M phase in miR-187* mimics group were significantly increased. CONCLUSION: miR-187* is down-regulated in human colon cancer cell lines. Up-regulation of miR-187* not only inhibits the proliferation but also influence the cell cycle of HCT116 cells, which might act as a tumor suppressor in colorectal cancer by inhibiting the expression of BMI-1.     

Effects of miR-337 targeting p53 expression on autophagy and migration ability of colon cancer cells

AIM: To investigate the effect of microRNA-337 (miR-337) on the autophagy and migration ability of colon cancer cells, and to explore its possible mechanism involving targeting p53 expression. METHODS: The me-thod of immunohistochemistry was used to detect the protein expression of beclin-1, LC3B and p53 in colon cancer tissues. The correlations between the protein expression of beclin-1/LC3B and clinicopathological features, and the correlations between the protein expression of p53 and beclin-1/LC3B were analyzed. After knock-down of p53 expression by small interfering RNA, the formation of autophagiosomes was observed under electron microscope in colon cancer cell line HCT116, and the protein expression of beclin-1 and LC3B was determined by Western blot. The miRNAs targeting p53 were predicted and screened by bioinformatics, and their expression in HCT116 cells was verified by RT-qPCR. Luciferase reporter assay was used to detect the regulatory effect of miR-337 on p53 gene. The protein expression of p53, beclin-1 and LC3B was determined by Western blot, and the migration ability of HCT116 cells after miR-337 over-expression was detected by Transwell assay. RESULTS: The protein expression of beclin-1 and LC3B in the colon cancer tissues was decreased, which was significantly related to the occurrence, development, invasion and metastasis of colon cancer. The expression of p53 was increased in the colon cancer tissues, which was negatively correlated with the protein expression of beclin-1 and LC3B. Knock-down of p53 gene expression increased the protein expression of beclin-1 and LC3B (P<0.05). Over-expression of miR-337 down-regulated the expression of p53, up-regulated the protein expression of beclin-1 and LC3B, and decreased the migration ability of HCT116 cells (P<0.05). CONCLUSION: miR-337 promotes autophagy and inhibits migration ability of colon cancer cells, and the mechanism may be related to targeted inhibition of p53 expression.     

Expression of hepatocyte nuclear factor 4α in experimental colitis in mice

AIM: To investigate the role of hepatocyte nuclear factor 4α (HNF4α) in the pathogenesis of ulcerative colitis (UC) by measuring the expression of HNF4α in the colon tissues in experimental colitis mice. METHODS: BALB/c mice were exposed to 2% or 2.5% (W/V) dextran sulfate sodium (DSS) to induce acute colitis, and the severity of colitis was assessed by observation of disease activity index (DAI), histological injuries and inflammatory cytokines. The correlation between the expression of HNF4α and the severity of disease as well as E-cadherin (E-CAD), junctional adhesion molecule 1 (JAM-1) and desmocollin 2 (DSC-2) was analyzed. RESULTS: Compared with the normal controls, DAI, histological injuries and the mRNA expression of inflammatory cytokines in DSS-treated mice were significantly elevated (P<0.05). The expression of HNF4α at protein and mRNA levels was significantly decreased (P<0.01). The result of Pearson analysis indicated an inverse correlation between the protein expression of HNF4α and the severity of disease (P<0.01). The positive correlation between the mRNA expression of HNF4α and E-CAD/JAM-1/DSC-2 (P<0.01) was also observed. CONCLUSION: There is a close relationship between the expression of HNF4α and the severity of colitis as well as the intercellular linking proteins. The low expression of HNF4α in intestine might aggravate the function of intestinal mucosal barrier, thus promoting the development of UC.     

Screening of differentially expressed genes in colorectal cancer based on TCGA database and verification of novel gene CCDC78

AIM To explore novel genes closely related to the prognosis of colorectal cancer through bioinformatics analysis of RNA sequencing (RNA-Seq） data of gene expression profile in large samples of colorectal cancer tissues from The Cancer Genome Atlas (TCGA) database, and to validate the new genes and study their functions. METHODS The RNA-Seq data were downloaded from TCGA database to screen differentially expressed genes, R-survival package was used to carry out survival analysis of differentially expressed genes to screened out genes related to prognosis of colorectal cancer, and the most significantly up-regulated genes that have not been reported in cancer studies were selected for further verification. RT-qPCR was employed to detect mRNA expression of these novel genes in human colon cancer cell lines and human colorectal cancer tissues. The colon cancer cell line with stable silencing of the novel gene expression was constructed by transfection of lentivirus vector, and its viability, migration and invasion were detected by CCK-8 assay and Transwell assay. RESULTS (1) A total of 4 017 differentially expressed genes were found in the gene expression profile of the colorectal cancer samples. Kaplan-Meier survival analysis showed that 69 genes were closely related to poor prognosis in patients with colorectal cancer, 36 of which were up-regulated, and 11 of these 36 genes have not been reported in cancer studies. (2) The mRNA expression of the top 3 up-regulated genes CCDC78, PGGHG and TSPEAR of the 11 genes was significantly increased in colon cancer cell lines, and the expression of CCDC78 mRNA was also up-regulated in colorectal cancer tissues. (3) CCDC78 gene silencing significantly suppressed the viability, migration and invasion of colon cancer cells (P<0.01). CONCLUSION Bioinformatics analysis based on TCGA database is helpful to discover nov?el genes related to prognosis of colorectal cancer, and CCDC78 may be a novel oncogene associated with poor prognosis of colorectal cancer.     

Correlation between E-cadherin and FOXO3a expression in gastric can-cer tissues and cells

AIM: To investigate the expression of E-cadherin and forkhead box protein O3a (FOXO3a) in gastric cancer tissues and cells, and its correlation with cell viability. METHODS: The expression of E-cadherin and FOXO3a was detected by immunohistochemical staining in 53 specimens of gastric cancer tissues and their adjacent tissues, and the relationship between their expression and clinicopathological characteristics were analyzed. E-cadherin-over-expressing gastric cancer AGS cells were constructed by lentivirus-mediated cell transfection, and the protein expression of E-cadherin and FOXO3a was detected by immunocytochemistry method. The expression of E-cadherin, FOXO3a, Akt, Bcl-2 and Bax was determined by Western blot. The cell viability was detected by CCK-8 assay. RESULTS: The positive expression rates of E-cadherin and FOXO3a proteins in gastric cancer tissues were both significantly lower than those in their adjacent tissues (P<0.05). E-cadherin positive expression in gastric cancer tissues was significantly related to tumor grade and TNM stage (P<0.05), but not related to age, sex, location, T stage or lymph node metastasis. FOXO3a positive expression was significantly related to tumor grade (P<0.05), but not related to age, sex, location, TNM stage, T stage or lymph node metastasis. The expression of E-cadherin was positively correlated with FOXO3a expression in gastric cancer tissues (r=0.376, P=0.003). After over-expression of E-cadherin, the viability of gastric cancer AGS cells was significantly inhibited, the expression of FOXO3a, Bcl-2 and Bax was significantly increased, and the expression of Akt was significantly decreased. CONCLUSION: E-cadherin and FOXO3a are involved in the development of gastric cancer, and E-cadherin may affect the viability of gastric cancer cells by regulating Akt/FOXO3a signaling pathway.     

Expression and clinical significance of PAK4 in non-small cell lung cancer

AIM: To investigate the expression and clinical significance of PAK4 in the cell lines and tissues of non-small cell lung cancer (NSCLC). METHODS: PAK4 expression in human bronchial epithelial (HBE) cells, NSCLC cell lines, NSCLC tissues and adjacent non-tumor tissues were assessed by immunohistochemistry, real-time PCR and Western blot. Prognostic value of PAK4 expression was evaluated by Kaplan-Meier analysis and Cox regression. RESULTS: PAK4 was over-expressed in the NSCLC cell lines at both mRNA and protein levels compared with HBE cells (P<0.05). PAK4 was over-expressed in the NSCLC tissues at both mRNA and protein levels compared with adjacent non-tumor tissues (P<0.05). PAK4 was over-expressed in the metastatic NSCLC tissues compared with the primary NSCLC tissues (P<0.05). Higher PAK4 staining scores were positively correlated with differentiation, lymph node metastasis, distant metastasis, and clinical stage. Kaplan-Meier analysis and log-rank test showed that overall survival was significantly different between the patients with up-regulated PAK4 and the patients with down-regulated PAK4(P<0.05). PAK4 over-expression was associated with NSCLC progression.CONCLUSION: Increased PAK4 expression was associated with tumor invasion, metastasis and prognosis in the patients with NSCLC. PAK4 is an important prognostic marker and potential therapeutic target in NSCLC.     

Level and clinical significance of RNA oxidative damage in human gastric cancer and para-carcinoma tissues

AIM: To investigate the RNA oxidative damage in human gastric cancer tissue and para-carcinoma tissue for exploring the role of RNA oxidation in the occurrence of gastric cancer. METHODS: Immunohistochemical observation and LC-MS/MS analysis were performed in 61 cases of gastric carcinoma. The position and concentration of 8-oxoguanosine (8-oxoGsn) were detected, respectively. RESULTS: The results of immunohistochemical observation showed that 8-oxoGsn was obviously up-regulated in the gastric cancer. The positive staining mainly accumulated in the cytoplasm of the tumor cells. The results of mass spectrometry showed that the level of 8-oxoGsn in the gastric cancer tissues was higher than that in the para-carcinoma tissues (P<0.05). CONCLUSION: 8-oxoGsn is up-regulated in gastric cancer. RNA oxidative damage may play important roles in the occurrence of gastric cancer.     

Effect of Wip1 gene silencing on chemotherapy sensitivity of human colon cancer cells

AIM: To observe the inhibitory effect of siRNA targeting to Wip1 gene on the Wip1 gene expression in the colon cancer cells and to investigate the influence of Wip1 gene silencing on the chemotherapy sensitivity of colon cancer cells. METHODS: Wip1-811 siRNA targeting to Wip1 gene was transfected into RKO colon cancer cells with high expression of Wip1 gene. The mRNA expression of Wip1 was measured by real-time PCR. The protein level of Wip1 was detected by Western blotting. The viability of RKO colon cancer cells was measured by MTS assay. The cell apoptosis and cell cycle were analyzed by flow cytometry. RESULTS: Wip1-811 siRNA efficiently inhibited the expression of Wip1 at mRNA and protein levels. The enhanced chemotherapy sensitivity of RKO colon cancer cells was observed after inhibition of Wip1 gene expression. The viability of RKO colon cancer cells was decreased from (89.4±6.6)% to (74.7±3.9)% after treated with 5-fluorouracil (P<0.05) and decreased from (77.9±2.4)% to (66.7±2.9)% after treated with oxaliplatin (P<0.05). The cell apoptotic rate was increased from (7.7±0.5)% to (12.3±3.2)% and from (14.7±2.1)% to (34.0±2.1)% when RKO colon cancer cells were treated with 5-fluorouracil and oxaliplatin, respectively (P<0.05). CONCLUSION: Wip1 gene silencing enhances chemotherapy sensitivity of colon cancer cells.     

Effect of Qiliqiangxin granule on apoptosis of renal tissues in rats with cardiorenal syndrome

AIM: To investigate the effect of Qiliqiangxin granule on the apoptosis of renal tissues in rats with cardiorenal syndrome (CRS) and its possible mechanism. METHODS: A rat model of CRS was established by ligation of the left anterior descending coronary artery and acute renal ischemia/reperfusion injury. After operation, the rats were divided into 6 groups:2-week sham operation (2w sham) group, 2-week model (2w CRS) group, 2-week drug (2w CRS-Q) group, 4-week sham operation (4w sham) group, 4-week model (4w CRS) group and 4-week drug (4w CRS-Q) group. The rats in 2w CRS-Q group and 4w CRS-Q group were given Qiliqiangxin granule (4 g·kg^-1·d^-1) by gavage for 2 weeks and 4 weeks, respectively. The levels of serum cystatin C (Cys-C), plasma angiotensin Ⅱ (Ang Ⅱ), urine neutrophil gelatinase-associated lipocalin (NGAL) and urine microalbumin (UMA) were measured by ELISA. The serum level of creatinine (Cre) was detected by sarcosine oxidase method. The renal histopathological changes were observed by HE staining. The mRNA and protein expression levels of Ang Ⅱ, Bcl-2 and Bax were evaluated by RT-qPCR and Western blot, respectively. The apoptosis rate of renal cells was assessed by TUNEL staining. RESULTS: The levels of serum Cys-C, serum Cre, plasma Ang Ⅱ, urine NGAL and UMA were significantly increased in 2w CRS group and 4w CRS group compared with 2w sham group and 4w sham group after modeling (P<0.05). The mRNA and protein expression levels of Bax and Ang Ⅱ in the renal tissues of CRS rats were significantly up-regulated (P<0.05), while Bcl-2 was significantly down-regulated (P<0.05) compared with 2w sham group and 4w sham group. Compared with 2w sham group and 4w sham group, the damage of renal tissues in 2w CRS and 4w CRS group was severe, and the apoptotic rates of renal cells were significantly increased. Compared with 2w CRS group and 4w CRS group, Qiliqiangxin granule greatly decreased the levels of Cys-C, Cre, Ang Ⅱ, NGAL and UMA, down-regulated the mRNA and protein expression levels of Bax and Ang Ⅱ in the renal tissues, and up-regulated the expression of Bcl-2 at mRNA and protein levels at 2 and 4 weeks. In addition, Qiliqiangxin granule also greatly attenuated the damage and apoptosis of the renal tissues. CONCLUSION: Qiliqiangxin granule significantly inhibits the apoptosis of renal tissues and improves the renal function of CRS rats, and its mechanism may be related to the inhibition of Ang Ⅱ expression.     

Phosphoproteomics to analyze PTPLAD1-regulated tyrosine-phosphorylated proteins in colon cancer cells

AIM: To identify and analyze tyrosine-phosphorylated proteins regulated by protein tyrosine phosphatase-like A domain containing protein 1 (PTPLAD1) in colon cancer cells by phosphoproteomics. METHODS: The expression of PTPLAD1 in colon cancer cell line HCT-116 was knocked down by small interfering RNAs, and the differential expression of tyrosine-phosphorylated proteins in response to the konckdown of PTPLAD1 in HCT-116 cells was identified by stable isotope labeling with amino acid in cell culture (SILAC), coupled with the tyrosine phosphorylation antibody immunoprecipitation and LC-MS/MS analysis. The Ingenuity Pathway Analysis (IPA) software was employed for bioinformatics analysis on the differentially-expressed proteins. RESULTS: A total of 20 differentially-expressed tyrosine-phosphorylated proteins were identified by MS, including 8 markedly up-regulated and 10 evidently down-regulated proteins. IPA software suggested that these proteins were mainly associated with the disease of cancer, tissue development and function, and cell death and survival. CONCLUSION: We successfully identified PTPLAD1-regulated differentially-expressed tyrosine-phosphorylated proteins in colon cancer cell line HCT-116. Our analysis suggests that PTPLAD1-regulated proteins in colon cancer are closely correlated with colon cancer.     

Differential expression profile of long non-coding RNA in hepatic tissue between drug-induced liver injury and immune liver injury

AIM: To analyze the expression profile of long non-coding RNA(lncRNA) in the liver tissues of drug-induced liver injury(DILI) and immune liver injury(ILI). METHODS: The technique of lncRNA microarray was used to inspect the lncRNA expression profile in the mouse liver tissues that the liver injury was induced by acetaminophen or concanavalin A. The raw data of lncRNA were pretreated for normalization. RESULTS: Compared with normal hepatic tissue, the lncRNA which had more than 1.5-fold variation and significant difference(P<0.05) by statistical analysis were regarded as lncRNA with differential expression. A total of 68 lncRNA with differential expression were found in the hepatic tissues of DILI, with 21 increased more than 1.5 folds and 47 reduced more than 1.5 folds. A total of 60 lncRNA with differential expression in the liver tissues of ILI were observed, with 17 increased more than 1.5 folds and 43 reduced more than 1.5 folds. In all lncRNA, 8 was simultaneously up-regulated in 2 liver injury models, accounting for 38% and 47% respectively, while 28 was simultaneously down-regulated in 2 liver injury models, accounting for 59% and 65% respectively. CONCLUSION: lncRNA expression profiles of DILI and ILI change significantly in comparison with normal hepatic tissue, and there are also differences between 2 hepatic damage models. The simultaneous changes of lncRNA may participate in the same or similar pathophysiological process, while the differences may be involved in relatively particular mechanisms.     

Expression of DNA repair gene ERCC1 and its relationship with PAH-DNA adducts in lung cancer tissues

AIM: To investigate the expression of nucleotide excision repair gene ERCC1 and its relationship with PAH (polycyclic aromatic hydrocarbons)-DNA adducts in lung cancer tissues. METHODS: ERCC1 mRNA expression and the PAH-induced DNA adducts were detected in 150 lung cancer tissues, 120 adjacent lung tissues without cancer cells, 40 benign lung lesions and 40 normal lung tissues. The effects of some exposure factors on the expression of ERCC1 gene and the connection between ERCC1 and PAH-DNA adduct was analyzed. RESULTS: Reduced expression levels of ERCC1 were observed in 46 of 150 (30.7%) lung cancer specimens and 1 of 40 (2.5%) normal lung tissues. Smoking may suppress the expression of ERCC1 gene. The level of PAH-DNA adduct was negatively correlated with the expression of ERCC1 gene, the Spearman coefficient was -0.648, P<0.01. CONCLUSION: ERCC1 is an important nucleotide excision repair gene and may participate in the repair of DNA damage, such as PAH-DNA adduct. Low expression of ERCC1 may play an important role in the development of human lung cancer.     

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.     

Differentially expressed microRNAs during solid endosperm development in coconut (Cocos nucifera L.)

MicroRNAs (miRNAs) are a class of 20–24 nt, endogenously expressed, non-coding RNAs that play important regulatory roles in plants and animals. To identify miRNAs potentially involved in tissue development and compound anabolism, we studied miRNA expression profiles in endosperm of coconut at different developmental stages. Based on the annotation in miRBase (release 10.1), we measured a total of 179 miRNAs in immature (95 expressed miRNAs) and mature tissues (176 expressed miRNAs) using microarrays, respectively. The comparative analyses on miRNA expression profiles between these two groups of tissues showed that 23 miRNAs were up-regulated and nine miRNAs were down-regulated in matured endosperm. We further confirmed the increased expression of four miRNAs and decreased expression of a miRNA in immature endosperm using real-time PCR. Moreover, we computationally predicted the target genes of 32 miRNAs with differential expression (p < 0.01), and identified the lowest-score targets of six miRNAs. Finally, we discussed the potential functional relevance of several differentially expressed miRNAs.     

Expression of GATA3 in human breast cancer tissues and its clinical significance

AIM: To investigate the expression of GATA3 in human breast carcinoma and its clinical significance. METHODS: The expression level of GATA3 in breast cancer tissues from 124 patients was detected by the method of immunohistochemistry and the relationships between GATA3 expression and other clinicopathological factors were analyzed. RESULTS: Low expression of GATA3 in breast cancer tissues was associated with estrogen receptor (ER)/progesterone receptor (PR) negative, high histological tumor grade, p53 mutation and vascular invasion (P<005), but not with age, tumor size,human epidermal growth factor receptor 2 (HER-2) expression and lymph node metastasis (P>005). In all breast cancer tissues, the positive expression rate of GATA3 was 56.4%. The positive expression rate of GATA3 in luminal breast cancer is 684%, higher than that in non-luminal breast cancer (326%, P<005). In all breast cancer tissues, the expression of GATA3 in middle recurrence risk group was higher than that in high recurrence risk group (P<005). CONCLUSION: GATA3 expression in breast cancer is related to differentiation and biological characteristics of the tumor, which can be a factor for evaluation of the treatment and prognosis.     

Priliminary analysis of microRNA expression profiles of side population cells in human colon cancer cell lines

AIM：To investigate the role of side population (SP) cells in multidrug resistance of colon cancer cells and microRNA biomarkers of SP cells in colon cancer cells. METHODS：SP cells in colon cancer cells were sorted by flow cytometry. The cell viability was measured by MTT method. MicroRNA expression profiles were detected by microRNA chip. MicroRNA expression was verified by real-time PCR. RESULTS：The ratios of SP cells in HCT-15, HT-29 and LoVo colon cancer cell lines were 16.75%, 13.02% and 9.52%, respectively. In all 3 colon cancer cell lines, IC50 of the antitumor drugs including 5-fluorouracil, oxaliplatin and adriamycin for the SP cells were significantly higher than those for non-SP cells (P<005). MicroRNA profiling showed that miR-5000-3p, miR-5009-3p and miR-552 were all up-regulated in the SP cells of all 3 colon cancer cell lines. This result was verified by real-time PCR. CONCLUSION：miR-5000-3p, miR-5009-3p and miR-552 are all up-regulated in the SP cells of colon cancer cell lines, and may be the potential microRNA biomarkers of SP cells in colon cancer.     

Functional analysis of differential microRNA expression profile in mouse fibrotic liver tissues induced by CCl4

AIM:To discover the expression profile of microRNAs (miRNAs) in mouse fibrotic liver tissues induced by carbon tetrachloride (CCl4), and to investigate the functions of these differential miRNAs based on the gene ontology (GO) analysis and KEGG Pathway analysis. METHODS:The mice were randomly divided into normal group and model group. Liver fibrosis was induced by subcutaneous injection of CCl4. miRNA expression profile of the liver tissues was assayed by a mouse miRNA microarray (Agilent 12.0). The differential expression of miRNAs between the normal and model mice was screened, and GO analysis and KEGG Pathway analysis were performed to determine the functions of these differential miRNAs. RESULTS:Thirty-nine miRNAs with differential expression were discovered in the model mice compared with the normal mice, among which 23 were up-regulated and 16 were down-regulated. GO analysis and KEGG Pathway analysis indicated that most pathological processes of liver fibrosis regulated by miRNAs included cell proliferation and activation, cell apoptosis, cell cycle, cell adhesion, inflammatory reaction, cell migration, transforming growth factor β (TGF-β) signaling pathway, Wnt signaling pathway and proteometabolism process. GO analysis revealed that the key up-regulated miRNAs were mmu-miR-322, mmu-miR-15b, mmu-miR-195, mmu-miR-200b and mmu-miR-214, and the key down-regulated miRNAs were mmu-miR-16, mmu-miR-130a, mmu-miR-101b, mmu-miR-30a and mmu-miR-30e. Analyzing the target genes screened out by GO analysis and Pathway analysis simultaneously, we found that the key up-regulated miRNAs included mmu-miR-200b, mmu-miR-322, mmu-miR-106b, mmu-miR-23a and mmu-miR-15b, and the key down-regulated miRNAs included mmu-miR-16, mmu-miR-30e, mmu-miR-30c, mmu-miR-30a and mmu-miR-130a. CONCLUSION: Differential expression of miRNAs is discovered in mouse fibrotic liver tissues induced by CCl4 compared with the normal liver tissues. Most of the pathological processes involved in liver fibrosis may be regulated by miRNA, such as cell proliferation and activation, cell adhesion and apoptosis, cell migration and differentiation, metabolism, TGF-β receptor signaling pathway and so on.     

Down-regulation of lncRNA PCAT1 suppresses oral squamous cell carcinoma cell proliferation,growth, invasion,migration and epithelial-mesenchymal transition

AIM: To investigate the effects of the long non-coding RNA (lncRNA) PCAT1 on the oral squamous cell carcinoma (OSCC) cell proliferation, growth, invasion and migration, and to explore the underlying mechanisms. METHODS: The PCAT1 siRNA was transfected by Lipofectmine 2000, and RT-qPCR and Western blot were performed to determine the mRNA and protein expression of relevant genes, respectively. CCK-8 assay and colony formation assay were used to measure OSCC cell proliferation and growth, respectively. The cell invasion and migration assays were used to measure the invasive and migratory abilities of the OSCC cells, respectively. RESULTS: PCAT1 was significantly up-regulated in OSCC tissues and cells compared with normal adjacent tissues and normal human oral keratinocyte cells, respectively (P<0.05). PCAT1 siRNA transfection suppressed the expression of PCAT1 in Tca8113 and TSCCa cells (P<0.05). Knockdown of PCAT1 in Tca8133 cells and TSCCa cells significantly suppressed the cell proliferation, invasion and migration abilities (P<0.05). In addition, knockdown of PCAT1 in Tca8133 cells and TSCCa cells also suppressed the mRNA and protein levels of ZEB-1, N-cadherin and vimentin, and increased the mRNA and protein expression of E-cadherin (P<0.05). CONCLUSION: Knockdown of PCAT1 suppresses cell proliferation and migration abilities, and the effect of PCAT1 on OSCC cells may be associated with epithelial-mesenchymal transition.