An increasing number of studies have demonstrated that circular RNAs (circRNAs) can regulate gene expression through interacting with microRNAs. In this study, we analyzed the expression of antisense to CDR1as in colorectal cancer (CRC). CDR1as had a higher expression in CRC tissues compared to adjacent, normal mucosa and was positively associated with tumor size, T stage, lymph node metastasis, and poor overall survival (OS). Downregulation of CDR1as suppressed CRC cell proliferation and invasion and increased microRNA-7 (miR-7) expression. Intriguingly, ectopic expression of miR-7 in CRC cells consistently inhibited proliferation and invasion, and the miR-7 inhibitor was able to rescue the function of CDR1as knockdown. Mechanistic studies demonstrated that CDR1as silencing suppressed EGFR and IGF-1R expression, which could be partially blocked by the miR-7 inhibitor. Finally, positive correlations between CDR1as expression and EGFR and IGF-1R expression were observed in CRC samples. Thus, given the importance of CDR1as in blocking miR-7 and positively regulating EGFR and IGF-1R, dysregulated CDR1as expression may play an important role in CRC progression.

Background: Growing evidence suggests that miR-150 plays an inhibitory role in various types of cancer. However, the function and underlying mechanisms of miR-150 in triple-negative breast cancer (TNBC) remain unknown. Patients and methods: miR-150 expression was detected by qRT-PCR and ISH in TNBC tumor and adjacent normal breast tissues. miR-150 function was analyzed by wound healing and transwell assay in vitro and mouse lung metastasis model in vivo. mRNA microarray, qRT-PCR, western blotting and luciferase assay were used to identify the target gene of miR-150. HMGA2 over-expression plasmid was co-transfected with miR-150 to study the role of miR-150 through regulating HMGA2. Results: We found that miR-150 was down-regulated in TNBC tumor tissues compared to corresponding adjacent, normal breast tissues, and was correlated with decreased lymph-node metastasis. Ectopic expression of miR-150 suppressed TNBC cell migration in vitro and metastasis in vivo. Mechanistic study revealed that miR-150 down-regulates HMGA2 by directly targeting its mRNA. Moreover, the suppression of cell migration caused by miR-150 is relieved by over-expression of HMGA2, suggesting that miR-150 inhibits migration of TNBC cells by down-regulating HMGA2. Conclusion: This work indicates that the miR-150/HMGA2 axis may serve as a treatment marker in TNBC.

Objective: This study aimed to compare the short-term and long-term outcomes between robotic-assisted simultaneous resection and open surgery in patients with rectal cancer and liver metastases. Background: Open simultaneous resection of colorectal cancer and synchronous liver metastases is widely performed and the potential cure for eligible patients. However, the feasibility of robotic simultaneous resection of primary and secondary liver lesions has not been established as a treatment option for metastatic rectal cancer. Patients and methods: A single-center randomized controlled trial was conducted at a hospital in China. Enrolling patients were aged from 18 to 75 years and diagnosed with surgically resectable metastatic rectal cancer (distal extension to ≤15 cm from the anal margin). Patients selected for simultaneous resection were randomly assigned to have robotic or open surgery at a 1:1 ratio. The primary endpoint was the incidence rate of complications within 30 days after surgery. Secondary endpoints were bladder, sexual function, 3-year disease-free survival, and overall survival. Results: A total of 171 patients were enrolled in this trial with 86 in the robotic group and 85 in the open group. As a result, patients in the robotic group demonstrated fewer complications within 30 days after surgery than those in the open group (31.4 vs. 57.6%, P=0.014) and no mortality seen in either group. Patients in the robotic group had less blood loss [mean (SD), 125.5 (38.3) vs. 211.6 (68.7) ml; P<0.001], faster bowel function recovery [mean (SD), 63.7 (27.4) vs. 93.8 (33.5) h P<0.001] and shorter hospital stay [mean (SD), 8.0 (2.2) vs. 10.7 (5.4) days; P<0.001] compared with those in the open group. The robotic group had a faster recovery of bladder and sexual function at 3 months after surgery than that of the open group. The 3-year disease-free survival rate (39.5 vs. 35.3%, P=0.739) and the 3-year overall survival rate (76.7 vs. 72.9%, P=0.712) were not statistically significant between the two groups. Conclusions: In our randomized clinical trial, robotic simultaneous resection treatment of patients with rectal cancer and liver metastases resulted in fewer surgical complications, and a faster recovery to those of open surgery. Oncological outcomes showed no significant difference between the two groups.

Purpose: This study aimed to evaluate the role of anatomical resection (AR) in lung metastasectomy (LM) of colorectal cancer (CRC) and to investigate clinically relevant prognostic factors. Patients and Methods: The medical records of 350 consecutive patients who underwent LM of CRC from 2011 to 2019 were reviewed. The patients were designated into AR group (lobectomy and segmentectomy), and non-anatomical resection (NAR) group (wedge resection), respectively. Kaplan–Meier method was used to analyze disease-free survival (DFS), pulmonary-specific disease-free survival (PDFS) and overall survival (OS). Cox proportional hazards regression model was performed to analyze the factors associated with DFS, PDFS and OS. Results: A total of 92 (31.2%) patients were enrolled in AR group and 203 (68.8%) in non-anatomical resection (NAR) group. AR significantly improved the 3-year DFS (64.1% vs 46.8%, HR 0.587, 95% CI 0.397– 0.867, P = 0.007) and PDFS (75.0% vs 60.1%, HR 0.565, 95% CI 0.356– 0.899, P = 0.016) compared with NAR. However, the extent of resection did not significantly impact the 3-year OS (AR 92.4% vs NAR 85.7%, HR 0.511, 95% CI 0.224– 1.165, P = 0.110). In multivariate analysis, AR was identified as a protective factor for DFS (HR 0.576, 95% CI 0.356– 0.934, P = 0.025) and PDFS (HR 0.631, 95% CI 0.409– 0.973, P = 0.037). Preoperative abnormal CA19-9 was identified as the only prognostic factor for OS. Conclusion: AR was superior to NAR for DFS and PDFS after LM from CRC.

Background: The type of liver resection (anatomical resection, AR or non-anatomical resection, NAR) for colorectal liver metastases (CRLM) is subject to debate. The debate may persist because some prognostic factors, associated with aggressive tumor biological behavior, have been overlooked. Objective: Our study aimed to investigate the characteristics of patients who would benefit more from anatomical resection for CRLM. Methods: Seven hundred twenty-nine patients who underwent hepatic resection of CRLM were retrospectively collected from June 2012 to May 2019. Treatment effects between AR and NAR were compared in full subgroup analyses. Tumor relapse-free survival (RFS) was evaluated by a stratified log-rank test and summarized with the use of Kaplan–Meier and Cox proportional hazards methods. Results: Among 729 patients, 235 (32.2%) underwent AR and 494 (67.8%) underwent NAR. We showed favorable trends in RFS for AR compared with NAR in the patients with KRAS/NRAS/BRAF mutation (interaction P<0.001) or right-sidedness (interaction P<0.05). Patients who underwent AR had a markedly improved RFS compared with NAR in the cohorts of RAS/NRAS/BRAF mutation (median RFS 23.2 vs. 11.1 months, P<0.001) or right-sidedness (median RFS 31.6 vs. 11.5 months, P<0.001); upon the multivariable analyses, AR [gene mutation: hazard ratio (HR)=0.506, 95% CI=0.371–0.690, P<0.001; right-sidedness: HR=0.426, 95% CI=0.261–0.695, P=0.001) remained prognostic independently. In contrast, patients who underwent AR had a similar RFS compared with those who underwent NAR, in the cohorts of patients with gene wild-type tumors (median RFS 20.5 vs. 21.6 months, P=0.333). or left-sidedness (median RFS 15.8 vs. 19.5 months, P=0.294). Conclusions: CRLM patients with gene mutation or right-sidedness can benefit more from AR rather than from NAR.

Background: N6-methyladenosine (m6A) modification plays crucial roles in cancers. However, its alteration in colorectal cancer (CRC) is still poorly described. The purpose of this study is to explore the change of m6A modification and the function of m6A binding protein YTHDC2 in CRC. Methods: The global level of m6A modification was detected by mass spectrometry and dot blotting assay. The expression of YTHDC2 was investigated using The Cancer Genome Atlas and using real-time polymerase chain reaction (RT-qPCR), western blotting, and immunohistochemistry based on CRC tissues. Kaplan–Meier analysis and Cox proportional hazards regression were performed to analyze the prognostic value of YTHDC2. RNA immunoprecipitation (RIP)-seq and m6A immunoprecipitation (MeRIP)-seq were used to explore the direct targets of YTHDC2. Gene oncology (GO) and Gene Set Enrichment Analysis (GSEA) were used to explore the pathways that could be influenced by YTHDC2. Results: No significant difference was observed in the global level of m6A modification on total RNA or mRNA between CRC and adjacent nontumor tissues. We further found a significant decreasing of YTHDC2 in CRC tissues. Kaplan–Meier analysis indicated that lower expression of YTHDC2 was related to the worse disease-free survival and overall survival. In addition, lower expression of YTHDC2 was an independent worse prognostic factor in univariate and multivariate Cox regression analysis. Using YTHDC2-RIP-seq and MeRIP-seq, we identified that YTHDC2 could participate in several important biological signal pathways. Conclusions: In summary, this study suggested that the global level of m6A did not change in CRC and identified that lower YTHDC2 as a prognostic marker for worse survival of CRC.