Integrative analysis of ceRNA network reveals functional lncRNAs associated with independent recurrent prognosis in colon adenocarcinoma.

BACKGROUND: Long non-coding RNAs (lncRNAs), acting as competing endogenous RNA (ceRNA) have been reported to regulate the expression of targeted genes by sponging miRNA in colon adenocarcinoma (COAD). METHODS: However, their potential implications for recurrence free survival prognosis and functional roles remains largely unclear in COAD. In this study, we downloaded the TCGA dataset (training dataset) and GSE39582 (validation dataset) of COAD patients with prognostic information. RESULTS: A total of 411 differentially expressed genes (DElncRNAs: 12 downregulated and 43 upregulated), 18 DE miRNAs (9 downregulated and 9 upregulated) and 338 DEmRNAs (113 downregulated and 225 upregulated) were identified in recurrence samples compared with non-recurrence samples with the thresholds of FDR < 0.05 and |log2FC|> 0.263. Based on six signature lncRNAs (LINC00899, LINC01503, PRKAG2-AS1, RAD21-AS1, SRRM2-AS1 and USP30-AS1), the risk score (RS) system was constructed. Two prognostic clinical features, including pathologic stage and RS model status were screened for building the nomogram survival model. Moreover, a recurrent-specific ceRNA network was successfully constructed with 2 signature lncRNAs, 4 miRNAs and 113 mRNAs. Furthermore, we further manifested that SRRM2-AS1 predicted a poor prognosis in COAD patients. Furthermore, knockdown of SRRM2-AS1 significantly suppressed cell proliferation, migration, invasion and EMT markers in HT-29 and SW1116 cells. CONCLUSION: These identified novel lncRNA signature and ceRNA network associated with recurrence prognosis might provide promising therapeutic targets for COAD patients.

Long non-coding RNA RP11-468E2.5 curtails colorectal cancer cell proliferation and stimulates apoptosis via the JAK/STAT signaling pathway by targeting STAT5 and STAT6.

BACKGROUND: Long non-coding RNAs (lncRNAs) are tumor-associated biological molecules and have been found to be implicated in the progression of colorectal cancer (CRC). This study aims to examine the effects of lncRNA RP11-468E2.5 and its target genes (STAT5 and STAT6) on the biological activities of CRC cells via the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway. METHODS: We initially screened the GEO database for differentially expressed lncRNAs related to CRC and then made a prediction of the implicated target genes. Then we collected CRC tissues and adjacent normal tissues from 169 CRC patients. Human CRC HCT116 and SW480 cells were treated with small interference RNA (siRNA) against RP11-468E2.5, AG490 (an inhibitor of the JAK/STAT signaling pathway), or both in combination. Next, we measured the effects of RP11-468E2.5 treatment on cellular activities such as cell viability, cycle distribution and cell apoptosis, and studied interactions among RP11-468E2.5, STAT5/STAT6, and the JAK/STAT signaling pathway. Finally, an in vivo tumor formation assay was performed to observe the effect of RP11-468E2.5 on tumor growth. RESULTS: The CRC-related gene microarray data showed low expression of RP11-468E2.5 in CRC surgical specimens. However, RP11-468E2.5 was confirmed to target STAT5 and STAT6, which participate in the JAK/STAT signaling pathway. CRC tissues showed lower expression of RP11-468E2.5, higher expression of STAT5, STAT6 and of the cell cycle marker Cyclin D1 (CCND1), compared to the findings in adjacent normal tissues. The treatment of siRNA against RP11-468E2.5 increased expression of JAK2, STAT3, STAT5, STAT6, CCND1 and Bcl-2 along with the extent of STAT3, STAT5 and STAT6 phosphorylation, while lowering expression of P21 and P27. Treatment with AG490 exhibited approximately opposite effects, whereas siRNA against RP11-468E2.5 treatment stimulated CRC cell proliferation and reduced cell apoptosis, while promoting cell cycle entry; AG490 treatment reversed these results. CONCLUSIONS: Altogether, we conclude that up-regulation of RP11-468E2.5 inhibits the JAK/STAT signaling pathway by targeting STAT5 and STAT6, thereby suppressing cell proliferation and promoting cell apoptosis in CRC.

ETV1 induces epithelial to mesenchymal transition in human gastric cancer cells through the upregulation of Snail expression.

The ETS family of transcription factors is involved in several physiological and pathological processes including tumor progression. The ETS transcription factors are divided into subfamilies based on the sequence and location of the ETS domain. ETV1 (Ets variant gene 1; also known as ER81), is a member of the PEA3 subfamily, which has been found to promote metastatic progression in several types of human cancer. Previous findings demonstrated that ETV1 expression is upregulated in gastric adenocarcinomas; however, the underlying mechanisms of ETV1-induced metastatic progression in gastric cancer remain elusive. In the present study, we found that the overexpression of ETV1 in normal gastric epithelial cells resulted in epithelial to mesenchymal transition (EMT) and increased invasiveness. Conversely, knockdown of ETV1 resulted in decreased aggressiveness of the invasive gastric cancer cells. Mechanistically, ETV1 transcriptionally upregulates Snail expression. Of note, ETV1 expression is significantly correlated with Snail expression in human gastric tumor samples. In summary, we present data that ETV1 promotes Snail expression to induce EMT-like metastatic progression in gastric cancer.

Comparison of percutaneous cryosurgery and surgical resection for the treatment of small hepatocellular carcinoma.

The present study aimed to compare the outcome of percutaneous cryosurgery (PC) with surgical resection (SR) in the treatment of solitary, small hepatocellular carcinoma (HCC), by performing a retrospective cohort study on 82 patients with solitary HCCs who had received either PC (24 patients) or SR (58 patients). All patients underwent pretreatment blood chemistry tests and an imaging evaluation and were regularly followed up with blood and radiological tests following treatment at The Third Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China. The primary endpoint was overall survival (OS) and the secondary endpoints were those of recurrence-free survival (RFS) and adverse events. In the study, the one-, three- and five-year OS rates following surgery were 100, 75.00 and 66.67%, respectively, in the PC group, and 100, 77.59 and 70.69%, respectively, in the SR group. The corresponding RFS rates at one, three and five years after PC and SR were 83.33, 45.83 and 29.17%, respectively, in the PC group and 84.48, 48.28 and 32.76%, respectively, in the SR group. There were no significant differences between these two groups in terms of OS and RFS. There were also no significant differences between the two groups in terms of OS and RFS when comparing the patients with liver cirrhosis (LC) in the PC group (n=16) and the patients with LC (n=39) in the SR group. No significant factors were identified in the multivariate analysis of the risk factors contributing to OS and RFS. Although there were no statistically significant differences between the two groups in terms of the rate of serious adverse events (P=0.82), the incidence of serious adverse events in the SR group was noticeably higher compared with the PC group. Moreover, the duration of hospitalization in the SR group was significantly longer compared with the PC group (P<0.01). These results suggested that PC is as effective as SR in the treatment of solitary, small HCC, while being less invasive, with a shorter duration of hospitalization and a reduction in patient expenditure compared with SR. Thus, PC may be the first choice for the treatment of solitary, small HCC.

STAT5a-targeting miRNA enhances chemosensitivity to cisplatin and 5-fluorouracil in human colorectal cancer cells.

Signal transducers and activators of transcription 5 (STAT5) has been shown to be involved in a variety of cellular processes, including survival, proliferation, invasion, angiogenesis and immune evasion and is frequently overexpressed in human solid tumors and blood malignancies. The aim of this study was to investigate the role of STAT5a in colorectal cancer (CRC) progression. We inhibited the expression of STAT5a using lentivirus-mediated artificial microRNA (miRNA) interference in vitro and investigated the viability of CRC cells by CCK-8 assay. We observed the cell viability after treatment with cisplatin (CDDP) or 5-fluorouracil (5-Fu) by CCK-8 assay, and the apoptosis induced by chemotherapy using flow cytometric analysis and Annexin V RFP staining assay. We inhibited the mRNA expression by 54% and the protein expression by 60% of STAT5 by RNA interference targeting STAT5a. Cell viability assays showed that inhibition of STAT5a did not affect the viability of SW1116 cells. However, we found that inhibition of STAT5a restored the sensitivity of SW1116 cells to CDDP and 5-Fu. In additional experiments, we found that inhibition of STAT5a significantly promoted CRC cell apoptosis by CDDP and 5-Fu. In the present study, we found that inhibition of STAT5a promotes apoptosis of CRC cells induced by chemotherapy drugs, such as CDDP or 5-Fu. These results suggest that inhibition of STAT5a may serve as a potential new target for CRC treatment.

Phospho-STAT5 expression is associated with poor prognosis of human colonic adenocarcinoma.

The signal transducer and activator of transcription-5 (STAT5) protein has been shown to play an important role in tumor progression through stimulating cell proliferation and preventing apoptosis. STAT5 activation has been observed in a variety of human tumors and cancer cell lines. However, it is not clear how activated STAT5 is expressed in colon cancer. In this study, we aimed to investigate phospho-STAT5 (activated form of STAT5) expression and its relationship with the clinicopathological factors and overall survival of patients with colonic adenocarcinoma. A total of 121 histological samples were selected for this study. Immunohistochemistry was used to detect the expression of phospho-STAT5. Analysis of the immunohistochemical staining was based on the proportion of stained cells in the field: positive, >15% stained cells, and negative, <15% stained cells. Survival times were analyzed using the Kaplan-Meier method, and the differences between groups were assessed with the log-rank test. A multivariate Cox regression model was used for prognostic power analysis. Expression of phospho-STAT5 was observed in the cytoplasms of colonic adenocarcinoma cells. Univariate analysis showed that phospho-STAT5 immunoreactivity was correlated with the depth of tumor invasion (P-value = 0.009), tumor-node-metastasis (TNM) stage (P-value = 0.048) and shorter overall survival times (P-value = 0.026). Lymph node metastasis, distant metastasis and TNM stage were associated with shorter overall survival times (P-value range from 0.003- < 0.001). Multivariate analysis showed that only distant metastasis was an independent predictor of overall survival time (P-value = 0.016). Our findings first demonstrate that phospho-STAT5 is frequently present and active in colonic adenocarcinoma and related to poor prognosis.

Expression of phosphorylated Stat5 predicts expression of cyclin D1 and correlates with poor prognosis of colonic adenocarcinoma.

PURPOSE: Constitutive activation of signal transducer and activator of transcription-5 (Stat5) was recently found to be associated with tumor progression through stimulating cell proliferation and preventing apoptosis. However, it is not clear how activated Stat5 is expressed in colon cancer. We aimed to investigate the correlation between phosphorylated Stat5 (p-Stat5) expression and cell cycle regulators (cyclin D1) expression in colonic adenocarcinoma and the relationship between expression of these two proteins and various clinicopathological parameters, including overall survival. METHODS: P-Stat5 and cyclin D1 expression were determined by immunohistochemical staining from 169 cases of resected colonic adenocarcinoma specimens. RESULTS: P-Stat5 expression correlated with cyclin D1 expression (r = 0.250, P = 0.001). P-Stat5-positive staining was associated with the depth of tumor invasion (P = 0.002). Univariate survival analysis showed that lymph node metastasis, distant metastasis, TNM stage (all P < 0.0001), T stage (P = 0.024), p-Stat5-positive expression (P = 0.002), and cyclin D1-positive expression (P = 0.039) were associated with shorter survival in patients with colonic adenocarcinoma. Multivariate survival analysis showed that only distant metastasis (P < 0.001; hazard ratio [HR] = 4.96), TNM stage (P < 0.001; HR = 9.80), and p-Stat5 overexpression (P = 0.020; HR = 1.84) were independent predictors of poor prognosis. CONCLUSIONS: Our findings provide the first evidence that p-Stat5 may play an important role in cyclin D1 overexpression and contribute to colonic adenocarcinoma progression.

Downregulation of MDM2 expression by RNAi inhibits LoVo human colorectal adenocarcinoma cells growth and the treatment of LoVo cells with mdm2siRNA3 enhances the sensitivity to cisplatin.

To investigate the biological effect of mdm2 in human colorectal adenocarcinoma LoVo cells, three mdm2siRNA constructions were recombined and transient transfected into human colorectal adenocarcinoma LoVo cells with low differentiation character in vitro. The results showed that mdm2siRNA3 reduced mRNA level of mdm2 and protein level of mdm2, leading to proliferation inhibition on LoVo cells, and reduced tumor growth in nude mice. It was found that depletion of MDM2 in this pattern promoted apoptosis of LoVo cells and Cisplatin (DDP) treated in the mdm2siRNA3 transfected cell population would result in a substantial decrease by MTT colorimetry. Decreasing the MDM2 protein level in LoVo cells by RNAi could significantly inhibit tumor growth both in vitro and in vivo, which indicated that mdm2 gene played a definite role in the development and aggressiveness of human colon carcinoma. It also could be a therapeutic target in colorectal carcinoma. The synergistic activation of RNAi and cell toxicity agents indicated that the combination of chemotherapy and gene therapy will be a promising approach in the future.