MYBL2 regulates de novo purine synthesis by transcriptionally activating IMPDH1 in hepatocellular carcinoma cells.

BACKGROUND: Metabolic reprogramming is a hallmark of cancer, alteration of nucleotide metabolism of hepatocellular carcinoma (HCC) is not well-understood. MYBL2 regulates cell cycle progression and hepatocarcinogenesis, its role in metabolic regulation remains elusive. PATIENTS AND METHODS: Copy number, mRNA and protein level of MYBL2 and IMPDH1 were analyzed in HCC, and correlated with patient survival. Chromatin Immunoprecipitation sequencing (Chip-seq) and Chromatin Immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR) were used to explore the relationship between MYBL2 and IMPDH1. Metabolomics were used to analyze how MYBL2 affected purine metabolism. The regulating effect of MYBL2 in HCC was further validated in vivo using xenograft models. RESULTS: The Results showed that copy-number alterations of MYBL2 occur in about 10% of human HCC. Expression of MYBL2, IMPDH1, or combination of both were significantly upregulated and associated with poor prognosis in HCC. Correlation, ChIP-seq and ChIP-qPCR analysis revealed that MYBL2 activates transcription of IMPDH1, while knock-out of MYBL2 retarded IMPDH1 expression and inhibited proliferation of HCC cells. Metabolomic analysis post knocking-out of MYBL2 demonstrated that it was essential in de novo purine synthesis, especially guanine nucleotides. In vivo analysis using xenograft tumors also revealed MYBL2 regulated purine synthesis by regulating IMPDH1, and thus, influencing tumor progression. CONCLUSION: MYBL2 is a key regulator of purine synthesis and promotes HCC progression by transcriptionally activating IMPDH1, it could be a potential candidate for targeted therapy for HCC.

Endoscopic management of delayed bleeding after polypectomy of small colorectal polyps: two or more clips may be safe.

Background: The resection of small colorectal polyps (≤10 mm) is routine for endoscopists. However, the management of one of its main complications, namely delayed (within 14 days) postpolypectomy bleeding (DPPB), has not been clearly demonstrated. We aimed to assess the role of coloscopy in the management of DPPB from small colorectal polyps and identify the associated factors for initial hemostatic success. Methods: We conducted a retrospective study of 69 patients who developed DPPB after the removal of colorectal polyps of ≤10 mm and underwent hemostatic colonoscopy at the Sixth Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) between April 2013 and June 2021. Demographics, clinical variables, and colonoscopic features were collected independently. We applied univariate and multivariate analyses to assess factors associated with initial hemostatic success. Results: General colonoscopy without oral bowel preparation was successfully performed in all the patients, with a median duration of 23.9 (12.5-37.9) minutes. Among 69 patients, 62 (89.9%) achieved hemostasis after initial hemostatic colonoscopy and 7 (10.1%) rebled 2.7 ± 1.1 days after initial colonoscopic hemostasis and had rebleeding successfully controlled by one additional colonoscopy. No colonoscopy-related adverse events occurred. Multivariate analysis showed that management with at least two clips was the only independent prognostic factor for initial hemostatic success (odds ratio, 0.17; 95% confidence interval, 0.03-0.91; P = 0.04). All the patients who had at least two clips placed at the initial hemostatic colonoscopy required no further hemostatic intervention. Conclusions: Colonoscopy is a safe, effective, and not too time-consuming approach for the management of patients with DPPB of small colorectal polyps and management with the placement of at least two hemoclips may be beneficial.

Laparoscopic Surgery for Complex Crohn's Disease: A Meta-Analysis.

Aim: There is still no consensus on whether laparoscopic surgery can be routinely recommended as a safe approach for complex Crohn's disease (CD). Methods: PubMed, Embase, and Cochrane library databases were searched (up to February 2019). Comparative studies reporting laparoscopic surgery for complex CD (LC group) comparing with simple CD (LS group) were included. The outcomes were blood loss, operative time, conversion rate, length of hospital stay, postoperative complications, and reoperation rate within 30 days after surgery. Results: Thirteen retrospective studies with 1120 participants were included. The LC group has significantly more blood loss (weighted mean difference [WMD] 43.64 mL; 95% confidence interval (CI) 8.37-78.91; P = .020), longer operative time (WMD 17.59 minutes; 95% CI 6.38-28.81; P = .002), higher conversion rate (WMD 2.04%; 95% CI 1.43-2.91; P < .001), and longer length of hospital stay (WMD 0.86 day; 95% CI 0.53-1.19; P < .001). Overall postoperative complication rates (WMD 0.98; 95% CI 0.71-1.34; P = .90) did not differ significantly between the 2 groups. Conclusions: LC is safe and feasible with comparable postoperative complications, although there is a more blood loss, longer operative time, higher conversion rate, and longer length of hospital stay.