High Expression of Ten Eleven Translocation 1 Is Associated with Poor Prognosis in Hepatocellular Carcinoma.

Background: DNA methylation patterns have been found to be distinct between tumor and normal patients. However, the effect of DNA demethylation enzymes, ten eleven translocation (TET) proteins, has not been comprehensively characterized in liver cancer. In this research, we sought to unravel the linkage of TET proteins with prognosis, immune characteristics and biological pathways in hepatocellular carcinoma (HCC). Materials and Methods: Four independent datasets with gene expression data and clinical data of HCC samples were downloaded from public databases. CIBERSORT, single sample Gene Set Enrichment Analysis (ssGSEA), MCP-counter, and TIMER were implemented to evaluate immune cell infiltration. limma was employed to screen differentially expressed genes (DEGs) between two groups. The demethylation-related risk model was established by using univariate Cox regression analysis, the least absolute shrinkage and selection operator (LASSO), and stepwise Akaike information criterion (stepAIC). Results: TET1 was significantly higher expressed in tumor samples than that in normal samples. HCC patients with advanced stages (III+IV) and grades (G3+G4) had higher TET1 expression compared to early stages (I+II) and grades (G1+G2). HCC samples with high TET1 expression had worse prognosis than that with low expression. High and low TET1 expression groups had distinct immune cell infiltration and response to immunotherapy and chemotherapy. We identified 90 DEGs related to DNA demethylation in high vs. low TET1 expression groups. Furthermore, we established a risk model based on 90 DEGs containing seven key prognostic genes (SERPINH1, CDC20, HACD2, SPHK1, UGT2B15, SLC1A5, and CYP2C9) with effectiveness and robustness in predicting HCC prognosis. Conclusions: Our study suggested TET1 as a potential indicator in HCC progression. TET1 was closely involved in immune infiltration and activation of oncogenic pathways. The DNA demethylation-related risk model was potential to be applied for predicting HCC prognosis in clinics.

Application of the En Bloc Concept Combined with Anatomic Resection in Laparoscopic Hepatectomy.

Laparoscopic hepatectomy has been reported in many studies, and it is the mainstream method of liver resection. In some particular cases, such as when there are tumors adjacent to the cystic bed, surgeons cannot palpate the surgical margins through the laparoscopic approach, which leads to uncertainty about R0 resection. Conventionally, the gallbladder is resected first, and the hepatic lobes or segments are resected second. However, tumor tissues can be disseminated in the above cases. To address this issue, based on the recognition of the porta hepatis and intrahepatic anatomy, we propose a unique approach to hepatectomy combined with gallbladder resection by en bloc anatomic resection in situ. Firstly, after dissecting the cystic duct, without cutting the gallbladder primarily, the porta hepatis is pre-occluded by the single lumen ureter; secondly, the left hepatic pedicle is made free by the gap of the Laennec membrane and Hilar plate; thirdly, the assistant is asked to drag the fundus of the gallbladder, and the liver parenchyma tissue is resected using a harmonic scalpel along the ischemia line on the liver surface and intraoperative ultrasound. The whole middle hepatic vein (MHV) and its tributaries appear completely; lastly, the left hepatic vein (LHV) is disconnected, and the specimen is taken out from the abdominal cavity. The tumor, gallbladder, and other surrounding tissues are resected en bloc, which meets the tumor-free criterion, and a wide incisal margin and R0 resection are achieved. Therefore, the laparoscopic hepatectomy with the combination of the en bloc concept and anatomic resection is a safe, effective, and radical method with low postoperative recurrence and metastasis.