Purpose: Circular RNAs (circRNAs), a novel class of noncoding RNAs, have recently drawn lots of attention in the pathogenesis of human cancers. However, the role of circRNAs in cancer cells epithelial-mesenchymal transition (EMT) remains unclear. In this study, we aimed to identify novel circRNAs that regulate urothelial carcinoma of the bladder (UCB) cells' EMT and explored their regulatory mechanisms and clinical significance in UCBs. Experimental Design: We first screened circRNA expression profiles using a circRNA microarray in paired UCB and normal tissues, and then studied the clinical significance of an upregulated circRNA, circPRMT5, in a large cohort of patients with UCB. We further investigated the functions and underlying mechanisms of circPRMT5 in UCB cells' EMT. Moreover, we evaluated the regulation effect of circPRMT5 on miR-30c, and its target genes, SNAIL1 and E-cadherin, in two independent cohorts from our institute and The Cancer Genome Atlas (TCGA). Results: We demonstrated that upregulated expression of circPRMT5 was positively associated with advanced clinical stage and worse survival in patients with UCB. We further revealed that circPRMT5 promoted UCB cell's EMT via sponging miR-30c. Clinical analysis from two independent UCB cohorts showed that the circPRMT5/miR-30c/SNAIL1/E-cadherin pathway was essential in supporting UCB progression. Importantly, we identified that circPRMT5 was upregulated in serum and urine exosomes from patients with UCB, and significantly correlated with tumor metastasis. Conclusions: CircPRMT5 exerts critical roles in promoting UCB cells' EMT and/or aggressiveness and is a prognostic biomarker of the disease, suggesting that circPRMT5 may serve as an exploitable therapeutic target for patients with UCB.

Chromobox homolog 8 (CBX8), also known as human polycomb 8, is a repressor that maintains the transcriptionally repressive state in various cellular genes, and has been reported to promote tumorigenesis. In the present study, we examined CBX8 expression in eight pairs of muscle invasive bladder cancer tissues and adjacent non‐tumor tissues, and found that CBX8 was frequently upregulated in muscle invasive bladder cancer tissues when compared to adjacent non‐tumor tissues. Analysis showed that high expression of CBX8 in 152 muscle invasive bladder cancer specimens was associated with progression of the T, N, and M stages (P = 0.004, 0.005, <0.001, respectively). Furthermore, Kaplan–Meier survival analysis and log–rank test showed that muscle invasive bladder cancer patients with high CBX8 expression had a poor rate of overall survival (P < 0.001) and 5‐year recurrence‐free survival (P < 0.001) compared to patients with low CBX8 expression. High CBX8 expression predicted poor overall survival and 5‐year recurrence‐free survival in T and N stages of muscle invasive bladder cancer patients. Moreover, knockdown of CBX8 inhibited cell proliferation of urothelial carcinoma of the bladder both in vitro and in vivo. In addition, CBX8 depletion resulted in cell cycle delay of urothelial carcinoma cells of the bladder at the G2/M phase by the p53 pathway. The data suggest that high expression of CBX8 plays a critical oncogenic role in aggressiveness of urothelial carcinoma cells of the bladder through promoting cancer cell proliferation by repressing the p53 pathway, and CBX8 could be used as a novel predictor for muscle invasive bladder cancer patients.

RNF2 (ring finger protein 2) is frequently overexpressed in several types of human cancer, but the status of RNF2 amplification and expression in urothelial carcinoma of the bladder (UCB) and its clinical/prognostic significance is unclear. In this study, immunohistochemical analysis and fluorescence in situ hybridization (FISH) were used to examine the expression and amplification of RNF2 in 184 UCB patients after radical cystectomy. Overexpression of RNF2 was observed in 44.0% of UCBs and was found to significantly associate with shortened overall and cancer-specific survival (P < 0.001). In different subsets of UCBs, RNF2 overexpression was also identified as a prognostic indicator in patients with pT1, pT2, pN(−), and/or negative surgical margins (P < 0.05). Importantly, RNF2 overexpression together with pT status and surgical margin status provided significant independent prognostic parameters in multivariate analysis (P < 0.01). FISH results showed amplification of RNF2 in 8/79 (10.1%) of informative UCB cases. Additionally, RNF2 overexpression was significantly associated with RNF2 gene amplification (P = 0.004) and cell proliferation (P = 0.003). These findings suggested that overexpression of RNF2, as examined by immunohistochemical analysis, might serve as a novel prognostic biomarker and potential therapeutic target for UCB patients who undergo radical cystectomy.

Background. There has been no prospective or retrospective studies reporting the comparison outcome between surgery and ablation for resectable-ablative (lesions could be treated by resection or complete ablation) colorectal liver oligometastases (CLOM). The purpose of this study was to compare the efficacy and prognostic difference in patients who underwent R0 resection vs. complete ablation within the resectable-ablative CLOM criteria. Methods. From January 2008 to May 2018, a total of 2,367 patients diagnosed with colorectal liver metastases were included in this observational study. The metastasis was characterized by only limited to liver with number ≤5, size ≤5 cm, and resectableablative (lesions could be treated by resection or complete ablation). The evaluated indications, including liver progression-free survival (LPFS), overall survival (OS), survival rates, pattern and number of recurrences, and complications, were compared by using propensity score matching (PSM). The Kaplan−Meier curves were generated, and a log-rank test was performed. The Cox regression model was used for univariate and multivariate analyses to identify predictors of outcomes. Results. A total of 421 consecutive patients were eligible for this study, with 250 and 171 undergoing R0 resection and complete ablation, respectively. PSM identified 145 patients from each group. The 1-, 3-, 5-and 8-year OS rates in the resection group and the ablation group were 95.8% vs. 95.0%, 69.8% vs. 60.1%, 53.6% vs. 42.5%, and 45.1% vs. 32.9% (p = 0.075), respectively. The median LPFS in the resection group was significantly longer than that in the ablation group (35 months vs. 15 months, p = 0.011). No statistical difference was found in LPFS between the two groups when comparing ≤3 cm liver metastases. For liver metastasis >3 cm, the median LPFS in the resection group and ablation group was 11 months and 5 months, respectively (p = 0.001). In terms of high risk of clinical risk score (CRS), the resection group showed longer LPFS than the ablation group (median 18 months vs. 10 months, p = 0.043). Conclusion. For patients within the CLOM criteria suggesting that liver metastases were resectable as well as ablative, resection could result in longer liver recurrence-free How to cite this article Luo M, Chen S-L, Chen J, Yan H, Qiu Z, Chen G, Lu L, Zhang F. 2020. Resection vs. ablation for lesions characterized as resectable-ablative within the colorectal liver oligometastases criteria: a propensity score matching from retrospective study. PeerJ 8:e8398 http://doi.org/10.7717/peerj.8398 survival than ablation in cases with size >3 cm or high risk of CRS. But for ≤3 cm liver metastases, their treatment efficacies were comparable. SA. 2004. Recurrence and outcomes following hepatic resection, radiofrequency ablation, and combined resection/ablation for colorectal liver metastases. Annals of Surgery 239:818-825 AC. 2015. The role of contrast-enhanced ultrasound in guiding radiofrequency ablation of hepatocellular carcinoma: a retrospective study. WY. 2006...