Colorectal cancer is a major public health problem and fourth guiding cause of cancer-induced mortality worldwide. The five-year survival rate for patients with colorectal cancer remains poor, and almost half of colorectal cancer patients present recurrence and die within five years. The increasing studies showed that long non-coding RNA (lncRNA) was involved in colorectal cancer. Therefore, this study was used to explore molecular mechanisms of nuclear paraspeckle assembly transcript 1 (NEAT1) in colorectal cancer. The real-time quantitative polymerase chain reaction (RT-qPCR) was employed to estimate the expression levels of NEAT1, Nuclear receptor 4 A1 (NR4A1), and miR-486-5p in colorectal cancer tissues and cells. Kaplan-Meier curve was conducted to analyze relationship between survival time of colorectal cancer patients and level of NEAT1. The protein levels of NR4A1, β-catenin, c-Myc, and cyclinD1 were assessed with western blot assay. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT) and flow cytometry assays were performed to evaluate proliferation and apoptosis of colorectal cancer cells, respectively. The migration and invasion abilities of cells were examined by transwell assay. The relationship between miR-486-5p and NEAT1 or NR4A1 was confirmed by dual-luciferase reporter assay. We found NEAT1 and NR4A1 were highly expressed in colorectal cancer tissues and cell lines compared with controls. Loss-functional experiments revealed that knockdown of NEAT1 or NR4A1 repressed proliferation and motility, while inducing apoptosis of colorectal cancer cells. The gain of NR4A1 could abolish NEAT1 silencing-induced effects in colorectal cancer cells. In addition, NEAT1 contributed to colorectal cancer progression through mediating NR4A1/Wnt/β-catenin signaling pathway. In conclusion, NEAT1 stimulated colorectal cancer progression via acting as competing endogenous RNA to sponge miR-486-5p and regulate NR4A1/Wnt/β-catenin signaling pathway.

ABSTRACT. The prognostic role of S100A4 in gastric cancer is still under debate. The present meta-analysis aimed to evaluate the relationship between S10A4 levels and the prognosis of gastric cancer. We performed a meta-analysis of published studies assessing the relationship between S100A4 and gastric cancer prognosis. We used the Revman 5.0 software to perform literature retrieval, article selection, data collection, and statistical analysis. A fixed-effect model was used to pool the hazard ratio (HR) and 95% confidence intervals (95%CI). A total of 7 eligible studies that included 1257 gastric cancer patients were analyzed. We did not find a prognostic value for S100A4 in gastric cancer (HR = 1.48, 95%CI = 0.77 to 2.82, P = 0.24). In conclusion, the present study indicated that S100A4 expression level is not a prognostic factor for gastric cancer.

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Purpose. To assess the association between intestinal venous blood (IVB) circulating tumor cells (CTCs) and clinicopathological parameters in stage I-III colorectal cancer (CRC) patients. Methods. Participants were retrospectively retrieved, who were admitted to our hospital or took annual physical exams between December 1, 2015 and December 31, 2018. A negative enrichment-immunofluorescence in situ hybridization (NE-imFISH) technique was used to isolate and identify CTCs. Receiver operating characteristic (ROC) curves and Youden index values were used to determine the critical CTC cutoff value for the diagnosis of CRC. Kaplan-Meier and log-rank methods were used to conduct survival analyses, and multivariate Cox regression analyses were employed for multivariate corrections to comprehensively evaluate the value of CTCs in the diagnosis of CRC. Relationships between IVB CTCs, clinicopathological parameters, and prognosis were then analyzed based upon patient postoperative follow-up data. Results. In total, we retrieved 282 patients including 48 healthy controls, 72 patients with benign colorectal tumors, and 162 CRC patients. CRC patients exhibited significantly higher numbers of CTCs relative to control patients or those with benign disease. CTC numbers in CRC patient peripheral blood (PB) and IVB were closely associated with tumor node metastasis (TNM) staging (P < 0.01), carbohydrate antigen-125 (CA-125) levels (P < 0.001), and KRAS (Kirsten rat sarcoma virus oncogene) mutation status (P < 0.001). The disease-free survival (DFS) of patients in the CTC-negative group was significantly longer than that of patients in the CTC-positive group (24.60 ± 13.31 months vs. 18.70 ± 10.19 months, P < 0.05), with the same being true with respect to their overall survival (OS) (30.60 ± 12.44 months vs. 35.25 ± 11.57 months, P < 0.05). A multivariate analysis revealed that the detection ≥2 CTCs/3.2 ml was independently associated with poorer DFS and OS. CTC counts were independently predictive of CRC patients TNM staging, CA-125, and KRAS mutation status in both univariate and multivariate Cox proportional hazards regression analyses. Conclusion. CTCs are valuable biomarkers that can be monitored to predict CRC patient disease progression.

Aberrant DNA methylation of genes is closely linked to many aspects of tumor development. This study focuses on the effect of DNA hypermethylation of von Willebrand factor C domain containing 2 (VWC2) on colorectal cancer (CRC) progression and the underpinning mechanism. According to data in the bioinformatic systems, VWC2 had the highest degree of DNA methylation in colonic adenocarcinoma, and it showed DNA hypermethylation in rectal adenocarcinoma as well. CRC and the para-tumorous tissues were collected from 86 patients. VWC2 was expressed at low levels in CRC samples and inversely correlated with tumor stage and tumor biomarker expression. DNA hypermethylation and reduced expression of VWC2 were also detected in CRC HCT-116 and HT29 cells. VWC2 overexpression suppressed the malignant growth of cells in vitro and in vivo. Coimmunoprecipitation and western blot assays showed that small ubiquitin-like modifier 1 (SUMO1) mediated SUMOylation of DNA methyltransferase 1 (DNMT1) and strengthened its protein stability, which promoted DNA methylation and suppression of the VWC2 gene. In summary, this study demonstrates that SUMO1-mediated activation of DNMT1 induces DNA methylation and downregulation of VWC2 in CRC to augment cancer development.