LINC00460 contributes to colorectal cancer cell invasion.

RESEARCH BACKGROUND: Colorectal cancer (CRC) is one of the most prevalent malignant tumors in the world. Research on long noncoding RNAs (LncRNAs) may illuminate tumorigenesis and progression of CRC. METHODS: We screened long non-coding RNA LINC00460 as a new candidate, which promoted the development of CRC in two independent datasets (GSE39582 and GSE21510) from the Gene Expression Omnibus (GEO). In 98 CRC tissues, expression levels of LINC00460 were significantly increased in cancerous tissues compared to paired adjacent normal tissues (P < 0.001). In addition, in the most common CRC cell lines. LINC00460 expression was up-regulated compared to normal human intestinal epithelial cell line NCM460. siRNA was transfected into CRC cell lines. LINC00460 knockdown reduced cell invasion ability and did not affect cell proliferation. The association between LINC00460 expression and clinical pathological features and prognosis were also analyzed. RESULTS: This increased expression was found to significantly correlate with lymph node metastasis (P = 0.002), distant metastasis (P = 0.045) and TNM stage (P < 0.001); but not related to age, gender, location of tumor, and histological grade. The overall survival (OS) in CRC patients with overexpression of LINC00460 was inferior to that with low expression (P = 0.0167). Multivariate Cox regression analyses indicated that LINC00460 expression, as well as TNM stage was an independent prognostic risk factor for patients with CRC. CONCLUSION: These results showed that a higher expression level of LINC00460 might play an oncogenic role in colorectal cancer invasion and metastasis. It also proved that LINC00460 might be used as a potential diagnostic and prognostic biomarker in CRC patients.

Activating IL-6/STAT3 Enhances Protein Stability of Proteasome 20S α+ß in Colorectal Cancer by miR-1254.

A widely recognized feature of colorectal cancer (CRC) is an increase in cytokine levels, which result in an inflammatory environment in the tumor. Interleukin-6 (IL-6) is a robust protumor cytokine. Several studies suggest that IL-6 plays a role in the development of tumors. Most intracellular protein breakdown occurs in eukaryotes via the ubiquitin-proteasome pathway; this mechanism may also be involved in cancer pathogenesis. The tumor tissues and paracancerous tissues were collected from 90 patients with colorectal cancer. The expressions of pSTAT3, proteasome 20S α+ß, miR-1254, and PSMD1 in tissues were detected by immunohistochemistry, ELISA, and qRT-PCR, and the effects of pSTAT3 and proteasome 20s α+ß expressions on the survival of patients were studied. HCT116 and HCT116-R cells were cultured and added IL-6, AG490, STAT3 plasmid, or overexpression/knockdown of miR-1254 in cells. Immunofluorescence, western blot, qRT-PCR, double luciferase gene reporter assay, and flow cytometry were used to detect the expression of pSTAT3, STAT3, proteasome 20s α+ß, miR-1254, and PSMD1 and cell cycle. The nude mouse xenograft model was constructed and divided into 3 groups: PBS group, IL-6 treatment group, and IL-6+miR-1254 mimic group. After 28 days, the tumor tissues were collected, and the expressions of miR-1254, pSTST3, proteasome 20s α+ß, and PSMD1 in the tissues were detected by qRT-PCR and immunohistochemistry, respectively. Our study discovered that the level of proteasome 20S α+ß had a strong connection with pSTAT3 in CRC patients. They were also linked to the development and clinical outcome of CRC. In addition, we found that IL-6 dramatically increased the expression of proteasome 20S α+ß and pSTAT3; however, it did not affect the proteasome 20S α+ß mRNA synthesis. Circulating proteasome concentration correlated with tumor tissue proteasome 20S α+ß. STAT3 could occupy the miR-1254 promoter to inhibit transcription, and it could suppressed miR-1254 which targeted PSMD10, promoting proteasome 20S α+ß protein stability. This is a prospective target for developing a new colorectal cancer therapy strategy.

VEGFR-2 as a novel predictor of survival in gastric cancer: A systematic review and meta-analysis.

BACKGROUND: Expression of VEGFRs may affect cancer prognosis. The aim of this work is to evaluate the prognostic significance of VEGFRs of patients with gastric cancer. METHODS: The databases PubMed, Embase, Web of Science, and Cochrane Library as well as ASCO and ESMO were searched systematically for articles reporting the prognostic significance of tissue VEGFRs in gastric cancer. The statistical analyses were carried out using Stata version 12.0. RESULTS: A total of 8 articles comprising 950 patients were eligible for meta-analysis. The combined HR of studies evaluating total VEGFRs overexpression was 1.42 (95% CI 1.01-2.00, P = 0.044), suggesting that it had prognosis significance in overall survival of gastric cancer. Subgroup analysis showed that it was VEGFR-2 (HR 1.81, 95% CI 1.31-2.49, P < 0.001) but not VEGFR-3 (HR 0.91, 95% CI 0.45-1.82, P = 0.787) overexpression was associated with an increased risk of median overall survival (mOS) and it can be a potentially predictive biomarker for gastric cancer. CONCLUSIONS: VEGFR-2 overexpression is a promising negative prognosis predictor for patients with gastric cancer. The prognosis significance of VEGFR-3 still need further study.

SDHB downregulation facilitates the proliferation and invasion of colorectal cancer through AMPK functions excluding those involved in the modulation of aerobic glycolysis.

Loss-of-function of succinate dehydrogenase-B (SDHB) is a predisposing factor of aerobic glycolysis and cancer progression. Adenosine monophosphate activated protein kinase (AMPK) is involved in the regulation of aerobic glycolysis and the diverse hallmarks of cancer. The present study investigated whether AMPK mediated the regulatory effects of SDHB in aerobic glycolysis and cancer growth. The expression of SDHB and AMPK in colorectal cancer (CRC) and normal tissues was assessed by western blotting. HT-29 CRC cells were used to establish in vitro models of ectopic overexpression and knockdown of SDHB. SDHB was downregulated, while AMPK and phosphorylated-AMPK (Thr172) were upregulated in CRC tissues. Experiments involving the loss- or gain-of-function of SDHB, revealed that this protein negatively regulated AMPK by influencing its expression and activity. However, SDHB and AMPK were identified to suppress lactic acid production in CRC cells, indicating that each had an inhibitory effect on aerobic glycolysis. Therefore, the regulation of aerobic glycolysis by SDHB is unlikely to be mediated via AMPK. SDHB knockdown promoted the viability, migration and invasion of HT-29 cells, whereas inhibition of AMPK demonstrated the opposite effect. SDHB overexpression impaired cell migration and invasion, and this effect was reversed following AMPK activation. These results indicate that AMPK may mediate the effects of SDHB in CRC cell proliferation and migration. In conclusion, SDHB downregulation in CRC cells may increase AMPK activity, which may subsequently facilitate the proliferation and invasion of these cancer cells. However, the regulation of aerobic glycolysis by SDHB may be independent of AMPK. Further studies are warranted to elucidate the mechanism by which SDHB regulates aerobic glycolysis.

miR-142-5p promotes development of colorectal cancer through targeting SDHB and facilitating generation of aerobic glycolysis.

Aberrant expression of miRNAs contributes to the development of human malignancies. A recent study revealed that miR-142-5p is increased in the serum of colorectal cancer (CRC) patients compared to health people. Using starBase v2.0, we found that succinate dehydrogenase-B (SDHB) is a potential target of miR-142-5p, while SDHB is negatively correlated to cancer development through regulating energetic metabolism. Based on these information, this study further examined the expression profiles of miR-142-5p and SDHB in CRC tissues and cell lines using PCR and Western blotting. Transfection experiment and luciferase assay were performed to identify relationship between miR-142-5p and SDHB. Oxygen intake, glucose consumption and production of lactic acid were used to evaluate the influence on energetic metabolism. CRC growth and proliferation were assessed by in vitro and in vivo studies. Results showed that miR-142-5p was up-regulated in CRC, but SDHB was down-regulated. SDHB was confirmed as a target of miR-142-5p, and decreased SDHB in CRC was result from the abnormal up-regulation of miR-142-5p. Lose of SDHB by miR-142-5p inhibited oxygen intake by CRC cells, but increased glucose consumption and lactate production. These suggest miR-142-5p up-regulation in CRC probably facilitates generation of aerobic glycolysis by reducing SDHB. miR-142-5p promoted proliferation and colony formation of CRC, but inhibited apoptosis. SDHB overexpression abrogated these effect of miR-142-5p, which indicates that SDHB depletion mediates tumor-promoting actions of miR-142-5p. This study added novel insight into the CRC development regulated by miR-142-5p. It may be a promising therapy target in the future molecular therapy.

MiR-590-5p, a density-sensitive microRNA, inhibits tumorigenesis by targeting YAP1 in colorectal cancer.

YAP1, a transcription co-activator, mediates the biological functions of the Hippo pathway. YAP1 inactivation is involved in cell-cell contact inhibition. In various tumors, YAP1 is upregulated through multiple mechanisms, and it functions as an oncogene. Here, we provided evidence that YAP1 influenced multiple signaling pathways in colorectal cancer (CRC) cells. We reported that miR-590-5p directly targets YAP1 and inhibits tumorigenesis in CRC cells both in vitro and in vivo xenograft model. We analyzed different cell densities and found that increased density caused increased expression of miR-590-5p, and decreased expression of its precursors (pri- and pre-miR-590). Increasing cancer cell density upregulated the expression of a RNase III endonuclease, DICER1. DICER1 increased miR-590 biogenesis and inhibited YAP1. In DICER1-defective CRC cells, addition of pre-miR-590 did not inhibit YAP1 expression. Analyses of clinical data demonstrated that the DICER1-miR-590-5p-YAP1 axis was dysregulated in CRC specimens and affected patient survival. Cell-cell contact inhibition is crucial to prevent uncontrolled cell proliferation. Identification of this cell density-sensitive, DICER1-miR-590-5p-YAP1 axis may provide a basis for developing new biomarkers or targeted therapies for CRC.

Prognostic value of lymph node metastasis in patients with T1-stage colorectal cancer from multiple centers in China.

AIM: To explore the features and prognostic value of lymph node metastasis in patients with T1-stage colorectal cancer (CRC). METHODS: In all, 321 cases of T1-stage CRC were selected from 10132 patients with CRC who received surgical therapy in six large-scale hospitals in China and were retrospectively analyzed. Univariate and multivariate analyses were performed to analyze the risk factors for lymphatic metastasis. A survival analysis was then performed to analyze the prognostic value of lymph node metastasis. RESULTS: The occurrence rate of T1 stage was 3.17% (321/10132); of these patients, the lymph node metastasis rate was 8.41% (27/321), and the non-lymph node metastasis rate was 91.59% (294/321). Univariate analysis showed that preoperative serum CEA, preoperative serum CA199, preoperative serum CA724, vascular invasion, and degree of differentiation were associated with lymph node metastasis in T1-stage CRC (P < 0.05 for all). Multivariate analysis indicated that preoperative serum CA724, vascular invasion, and degree of differentiation were closely related to lymph node metastasis (P < 0.05 for all). Log-rank survival analysis showed that age, preoperative serum CEA, preoperative serum CA199, vascular invasion, degree of differentiation, and lymph node metastasis (χ2 = 24.180, P < 0.001) were predictors of 5-year overall survival (OS) (P < 0.05 for all). COX regression analysis demonstrated that preoperative serum CA199 and lymph node metastasis (HR = 5.117; P < 0.05; 95%CI: 0.058-0.815) were independent prognostic indicators of 5-year OS in patients with T1-stage CRC (P < 0.05 for both). CONCLUSION: The morbidity of T1-stage CRC was 3.17% for all CRC cases. Preoperative serum CA724, vascular invasion, and degree of differentiation are independent risk factors for lymph node metastasis. Lymph node metastasis is an independent prognostic factor for OS in patients with T1-stage CRC.

Aberrant Expression of CUL4A Is Associated with IL-6/ STAT3 Activation in Colorectal Cancer Progression.

BACKGROUND AND AIMS: Although it has been indicated that the cytokine interleukin-6 (IL-6) promotes colorectal cancer (CRC) tumorigenesis in tumor microenvironment, the mechanisms related to IL-6-induced tumor progression are still not well understood. METHODS: First, the correlation between pSTAT3, CUL4A and ZEB1 was analyzed using immunocytochemistry. Logistic regression analysis was then used to observe the relationship between levels of pSTAT3, CUL4A and ZEB1 and clinicopathological characteristics. Finally, the mechanism of the effect of the expression level of pSTAT3, CUL4A and ZEB1 on cell invasion ability was verified by cell experiment. RESULTS: We discovered that the increased expression levels of pSTAT3, CUL4A and ZEB1 had significant relationships in CRC patients. These up-regulated expression levels were also closely associated with CRC aggressiveness. Furthermore, in vitro, we discovered that expression levels of CUL4A and ZEB1 were significantly up-regulated when IL-6 stimulated. However, the CUL4A-knockdown, IL-6, could not induce expression of ZEB1. CHIP assay authenticated that pSTAT3 could bind to CUL4A promoter and worked as their transcription factors. We also demonstrated that IL-6 markedly increased the reporter activity using a luciferase reporter gene containing CUL4A promoter. Finally, silencing CUL4A blocked IL-6-driven invasion in matrigel invasion assay. CONCLUSION: This study proposed that CUL4A played an oncogene role through ZEB1 in IL-6-induced colorectal carcinoma progression.

Downregulation of long non-coding RNA ANRIL suppresses lymphangiogenesis and lymphatic metastasis in colorectal cancer.

This study aimed to investigate the effect of ANRIL on the lymphangiogenesis and lymphatic metastasis in colorectal cancer. Using RT-PCT and Northern blot, we detected ANRIL expression in tissues (cancer vs. normal) and cell lines (HCoEpic, SW480, HT29, LoVo and HCT116), finding that ANRIL was overexpressed in colorectal cancer. By statistical analysis, increased ANRIL was found to be in close association with TNM staging, Duke staging and lymphatic metastasis and poor prognosis. We down-regulated the high ANRIL expression in LoVo and HCT116 with lentivirus transfection, and found that the activity of cell mobility and invasion was remarkably reduced. And also we also identified that ANRIL down-regulation could suppress in-vitro tube formation HLECs invasion. In addition, we built a mouse model of colorectal cancer. In the mouse model, we recorded, after ANRIL downregulation, decreased tumor growth rates and tumor size and reduced lymphatic metastasis rate and frequency of transferred lymph nodes, LMVD and expressions of VEFG-C, VEGFR-3 and LYVE-1. Based on these findings, we concluded that increased ANRIL is promoter in the development of colorectal cancer. Through down-regulation of the overexpressed ANRIL, lymphangiogenesis may be suppressed and therefore lymphatic metastasis may be inhibited. On this ground, we suggest that ANRIL may be a therapeutic target for colorectal cancer.

Jak-STAT3 pathway triggers DICER1 for proteasomal degradation by ubiquitin ligase complex of CUL4A(DCAF1) to promote colon cancer development.

Chronic intestinal inflammation is closely associated with colon cancer development and STAT3 seems to take center stage in bridging chronic inflammation to colon cancer progress. Here, we discovered that DICER1 was significantly downregulated in response to IL-6 or LPS stimulation and identified a novel mechanism for DICER1 downregulation via proteasomal degradation by ubiquitin ligase complex of CUL4A(DCAF1) in colon cancer cells. Meanwhile, PI3K-AKT signaling pathway phosphorylated DICER1 and contributed to its proteasomal degradation. The regulation of DICER1 by CUL4A(DCAF1) affected cell growth and apoptosis which is controlled by IL-6 activated Jak-STAT3 pathway. Intervention of CUL4A(DCAF1) ubiquitin ligase complex led to fluctuation in expression levels of DICER1 and microRNAs, and thus affected tumor growth in a mouse xenograft model. A panel of microRNAs that were downregulated by IL-6 stimulation was rescued by siRNA-CUL4A, and their predicated functions are involved in regulation of cell proliferation, apoptosis and motility. Furthermore, clinical specimen analysis revealed that decreased DICER1 expression was negatively correlated with STAT3 activation and cancer progression in human colon cancers. DICER1 and p-STAT3 expression levels correlated with 5-year overall survival of colon cancer patients. Consequently, this study proposes that inflammation-induced Jak-STAT3 signaling leads to colon cancer development through proteasomal degradation of DICER1 by ubiquitin ligase complex of CUL4A(DCAF1), which suggests a novel therapeutic opportunity for colon cancer.

Anticancer activity of bicalutamide-loaded PLGA nanoparticles in prostate cancers.

Prostate cancer is the most commonly diagnosed non-cutaneous malignancy in men in western and most developing countries. Bicalutamide (BLT) is an antineoplastic hormonal agent primarily used in the treatment of locally advanced and metastatic prostate cancers. In the present study, the aim was to develop a nanotechnology-based delivery system to target prostate cancer cells. This involved the development of a BLT-loaded poly(D,L-lactide-co-glycolide) PLGA (PLGA-BLT) nanoparticulate system in an attempt to improve the therapeutic efficacy of BLT in prostate cancer and to mitigate its toxicity. Nanosized particles with a uniform size distribution and spherical shape were developed. PLGA-BLT showed a pronounced cytotoxic effect on LNCaP and C4-2 cancer cells. The superior cell-killing effect of the nanoparticles may be attributable to their sustained drug-release characteristics and high cellular internalization. PLGA-BLT was also found to significantly inhibit colony formation in the two cell lines. Furthermore, the caspase-3 activity of PLGA-BLT treated cancer cells was enhanced, indicating the cell apoptosis-inducing potential of PLGA-BLT. Overall, these results suggest that nanotechnology-based formulations of BLT exhibit superior anticancer activity and have enormous potential in the treatment of prostate cancers.

Prognostic Value of Yes-Associated Protein 1 (YAP1) in Various Cancers: A Meta-Analysis.

BACKGROUND: Yes-associated protein 1 (YAP1) is an effector of Hippo pathway, which is critical for regulating organ size, cell proliferation and tumor growth in mammals. Many previous studies have explored the relationship between YAP1 and various types of cancer. However, these studies were limited by the small samples size and the findings were inconsistent among them. Therefore, a meta-analysis was conducted to assess the association between YAP1 and malignancies. METHODS: A systematic literature search was conducted for eligible studies in the PubMed, Corchane Library, Web of Knowledge, EMBASE and CBM disc databases from inception to August 1st 2014. After heterogeneity analysis, pooled harzad ratio (HR) with 95% confidence interval (95%CI) using both fixed and random effect models were estimated in STATA 10.0. Meta regression analysis, subgroup analysis and sensitivity analysis were performed to explore the potential sources of heterogeneity and to evaluate the robustness of the result. Publication bias was assessed by Egger's test and funnel plot. RESULTS: A total of 21 unique articles from 2009 to 2014, comprising 2983 patients, were analyzed in the meta-analysis. The association of YAP1 expression and overall survival time (OS) was evaluated in 20 studies including 2067 patients. Positive YAP1 showed poorer OS (HR = 1.826; 95% CI = 1.465-2.275; p <0.002). For evaluating disease-free survival time (DFS), 10 studies with 1139 patients were analyzed. Positive YAP1 indicated worse DFS (HR = 2.114; 95%CI = 1.406-3.179; p <0.001). Subgroup analysis showed that both positive nuclear YAP1 (HR = 1.390, 95% CI: 0.810-2.400, p = 0.729) and up-regulation overall YAP1 (HR = 2.237, 95% CI: 1.548-3.232, p <0.001) had poorer OS for patients with malignancies. Similarly, both positive nuclear YAP1 (HR = 3.733, 95% CI: 1.469-9.483, p = 0.001) and up-regulation overall YAP1 (HR = 1.481, 95% CI: 1.163-1.886, p = 0.554) showed worse DFS. The patients with urogenital system cancer had the poorest OS (HR = 2.133, 95% CI: 1.549-2.937, p = 0.020). The patients with alimentary system cancer had the most significant impact on DFS (HR = 1.879, 95% CI: 1.537-2.297, p <0.001). CONCLUSION: Both overall and nuclear YAP1 overexpression are intimately associated with adverse OS and DFS in numerous cancers, suggesting that YAP1 may act as a potential therapeutic targets of these malignancies in the future.

Human mutL homolog 1 expression characteristic and prognostic effect on patients with sporadic colorectal cancer.

The aim of the present study was to analyze the relationship between aberrant human mutL homolog 1 (hMLH1) expression and clinicopathological parameters of patients with sporadic colorectal cancer, and to explore the prognostic effect of aberrant hMLH1 expression in these patients. The relationship was measured by chi-square test and Fisher's exact test. Survival analysis was performed with Kaplan-Meier analysis and Cox regression model to measure 5-year disease-free survival (DFS) and 5-year overall survival (OS) rates. Totally 17.13% of the patients with sporadic colorectal cancer showed aberrant nuclear staining for hMLH1 expression. Aberrant hMLH1 expression was related with tumor pathologic types, tumor location and TNM staging (P<0.05) in the patients with sporadic colorectal cancer. Cox regression analysis indicated important prognostic factors were age (RR: 1.021, 95% CI: 1.003-1.039, P=0.023), mucinous adenocarcinoma (RR: 2.603, 95% CI: 1.705-3.974, P<0.0001), TNM staging (RR: 2.071, 95% CI: 1.170-3.666, P=0.012), lymphangion invasion (RR: 2.013, 95% CI: 1.227-3.303, P=0.006) and aberrant hMLH1 expression (RR: 0.414, 95% CI: 0.216-0.791, P=0.008). Consequently, hMLH1 expression level is related with some clinicopathologic features. Aberrant hMLH1 expression plays a significant part in prognosis for patients with sporadic colorectal cancer and it will promisingly become an independent prognostic factor.

The ratio of circulating regulatory T cells (Tregs)/Th17 cells is associated with acute allograft rejection in liver transplantation.

CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) and Th17 cells are known to be involved in the alloreactive responses in organ transplantation, but little is known about the relationship between Tregs and Th17 cells in the context of liver alloresponse. Here, we investigated whether the circulating Tregs/Th17 ratio is associated with acute allograft rejection in liver transplantation. In present study, thirty-eight patients who received liver transplant were enrolled. The patients were divided into two groups: acute allograft rejection group (Gr-AR) (n = 16) and stable allograft liver function group (Gr-SF) (n = 22). The frequencies of circulating Tregs and circulating Th17 cells, as well as Tregs/Th17 ratio were determined using flow cytometry. The association between Tregs/Th17 ratio and acute allograft rejection was then analyzed. Our results showed that the frequency of circulating Tregs was significantly decreased, whereas the frequency of circulating Th17 cells was significantly increased in liver allograft recipients who developed acute rejection. Tregs/Th17 ratio had a negative correlation with liver damage indices and the score of rejection activity index (RAI) after liver transplantation. In addition, the percentages of CTLA-4(+), HLA-DR(+), Ki67(+), and IL-10(+) Tregs were higher in Gr-SF group than in Gr-AR group. Our results suggested that the ratio of circulating Tregs/Th17 cells is associated with acute allograft rejection, thus the ratio may serve as an alternative marker for the diagnosis of acute rejection.