A novel mechanism of the M1-M2 methionine adenosyltransferase switch-mediated hepatocellular carcinoma metastasis.

Hepatocellular carcinoma (HCC) manifests as a highly metastatic cancer with extremely poor prognosis. However, mechanisms underlying metastasis of HCC are not fully understood. Here, we showed that switching gene expression from MAT1A to MAT2A (M1-M2 switch) promoted cancer invasion and metastasis. Reversion of the M1-M2 switch repressed, whereas enhancing the M1-M2 switch promoted the ability of HCC cells to metastasize. Moreover, we provided clinical data showing that tipping the balance between MAT1A and MAT2A expression correlated with increased metastasis and inferior recurrence-free survival in HCC patients. Molecular pathways analysis showed that downregulation of MAT1A, which augmented osteopontin (OPN) expression through decreasing methylation of the OPN promoter, and MAT2A upregulation, which induced integrin ß3 (ITGB3) expression by binding to ITGB3 promoter, collaboratively triggered ERK signaling and thereby promoted metastasis. Thus, the simultaneous downregulation of MAT1A and upregulation of MAT2A are necessary and sufficient for HCC metastasis in the process of M1-M2 switch. Our findings provide novel mechanistic insights into cancer metastasis. Inhibition and prevention of the M1-M2 switch would offer a novel therapeutic option for treatment of HCC.

Initial Experience: Alleviation of Pain with Percutaneous CT-Guided Cryoablation for Recurrent Retroperitoneal Soft-Tissue Sarcoma.

PURPOSE: To evaluate the pain-alleviating effect of computed tomography (CT)-guided percutaneous cryoablation for recurrent retroperitoneal soft-tissue sarcomas (RPSs). MATERIALS AND METHODS: Data from 19 men and 20 women (median age, 50.3 y) with recurrent malignant RPS who underwent percutaneous cryoablation were reviewed retrospectively. A total of 50 tumors were treated by cryoablation, including a single tumor in 29 patients, 2 tumors in 9, and 3 tumors in 1. Adverse events and analgesic outcomes were compared as a function of tumor size (< 10 cm and ≥ 10 cm). Efficacy was assessed based on modified Response Evaluation Criteria In Solid Tumors and progression-free survival (PFS). RESULTS: Grade 1/2 adverse events included fever (n = 17), emesis (n = 7), frostbite (n = 5), and local pain (n = 4). The median follow-up period and PFS were 18.5 months (range, 12-42 mo) and 13.4 months ± 6.2, respectively. At the end of follow-up, 13 patients had died and 26 were living. The mean severe local pain scores on pretreatment day 1 and posttreatment days 1, 5, 10, 15, 20, and 25 were 7.49, 7.40, 6.51, 5.81, 5.35, 5.04, and 5.44, respectively, and significant differences versus pretreatment (P < .001) were reported for posttreatment days 5-25. Immediate relief occurred more frequently in the small-tumor group (4 of 7; 57.1%; P = .018), whereas delayed relief occurred more frequently in the large-tumor group (17 of 22; 77.3%; P = .030). CONCLUSIONS: Minimally invasive percutaneous cryoablation improves local pain and is a feasible treatment for recurrent RPSs.

[Construction of the enhanced green fluorescent protein eukaryotic expression vector carrying CagA of Helicobacter pylori].

OBJECTIVE: To construct a eukaryotic green fluorescent protein expressing vector containing the fragment of cytotoxin associated gene A (CagA) of Helicobacter pylori (Hp) so as to lay a foundation for the research of gene vaccine of gastric cancer. pEGFP-C3-CagA. METHODS: The fragment of gene CagA was amplified from Hp using PCR. The amplified product was examined by electrophoresis and sequence determination. This fragment was inserted into pGEM-T plasmid and pEGFP-C3 fluorescent expression vector. The recombined plasmid pEGFP-C3-CagA was transfected into the gastric carcinoma cells of the strain BGC823 by lipoplasty method. Fluorescence microscopy was used to observe the expression of pEGFP-C3-CagA under. RESULTS: CagA was inserted in the plasmid correctly. It was verified by DNA sequencing and restriction enzyme. The enhanced green fluorescent protein eukaryotic expression vector carrying CagA of Helicobacter pylori (pEGFP-C3-CagA) was recombined correctly and transfected in gastric carcinoma cell strain BGC823. Green fluorescence was observed in transfected gastric carcinoma cell. CONCLUSION: Construction of the enhanced green fluorescent protein eukaryotic expression vector carrying CagA was successful.