Genome-scale CRISPR activation screening identifies a role of LRP8 in Sorafenib resistance in Hepatocellular carcinoma.

Sorafenib may provide survival benefits for patients with advanced hepatocellular carcinoma. However, tumor cells can display primary or secondary resistance to Sorafenib. To identify genes capable of conveying Sorafenib resistance, we performed a genome-wide CRISPR transcriptional activation library (SAM) in human Huh7 cells. We identified that a group of sgRNAs were significantly enriched in Sorafenib resistant Huh7 cells, which indicated that these sgRNAs up-regulated their target genes and induced resistance. We finally identified LRP8 as a key gene that can drive HCC cell to acquire sorafenib resistance. All three sgRNAs targeting LRP8 were identified in Sorafenib resistant Huh7 cells with high copy. We also showed that sorafenib-acquired resistant Huh7 cells have much higher LRP8 expression level than parental Huh7 cells. We proved that overexpression of LRP8 in HCC cell lines activated ß-catenin and significantly promoted its resistance to Sorafenib. We further showed that overexpression of LRP8 reduced the apoptosis level of HCC cell lines. To summary, genome-scale CRISPR activation screening identifies a role of LRP8 in Sorafenib resistance in Hepatocellular carcinoma.

Targeting the TCA cycle through cuproptosis confers synthetic lethality on ARID1A-deficient hepatocellular carcinoma.

ARID1A is among the most commonly mutated tumor suppressor genes in hepatocellular carcinoma (HCC). In this study, we conduct a CRISPR-Cas9 synthetic lethality screen using ARID1A-deficient HCC cells to identify approaches to treat HCC patients harboring ARID1A deficiency. This strategy reveals that the survival of these ARID1A-deficient HCC cells is highly dependent on genes related to the tricarboxylic acid (TCA) cycle. Mechanistically, ARID1A loss represses expression of key glycolysis-related gene PKM, shifting cellular glucose metabolism from aerobic glycolysis to dependence on the TCA cycle and oxidative phosphorylation. Cuproptosis is a recently defined form of copper-induced cell death reported to directly target the TCA cycle. Here, we find that ARID1A-deficient HCC cells and xenograft tumors are highly sensitive to copper treatment. Together, these results offer evidence of the synthetic lethality between ARID1A deficiency and mitochondrial respiration impairment, suggesting that copper treatment constitutes a promising therapeutic strategy for selectively targeting ARID1A-deficient HCC.

MTF2 Induces Epithelial-Mesenchymal Transition and Progression of Hepatocellular Carcinoma by Transcriptionally Activating Snail.

BACKGROUND: Metal regulatory transcription factor 2 (MTF2) has been previously reported as a protein binding to the metal response element of the mouse metallothionein promoter, which is involved in chromosome inactivation and pluripotency. However, the function of MTF2 in tumor formation and progression has not yet been completely elucidated. METHODS: The expression of MTF2 and clinicopathological characteristics were evaluated by hepatocellular carcinoma (HCC) tissue microarray of 240 specimens. The role of MTF2 on HCC progression was determined using MTT, crystal violet, and transwell assays. Tumor growth was monitored in a xenograft model, and intrahepatic metastasis models were established. RESULTS: The expression of MTF2 was increased in HCC and strongly associated with the clinical characteristics and prognosis. Forced expression of MTF2 in HCC cells significantly promoted cell growth, migration, and invasion in vitro. In contrast, downregulation of MTF2 inhibited cell growth, migration, and invasion in vitro. Moreover, knock down of MTF2 suppressed tumorigenesis and intrahepatic metastasis of HCC cells in vivo. Mechanistically, MTF2 overexpression may promote growth and epithelial-mesenchymal transition processes of HCC cells by facilitating Snail transcription. CONCLUSION: MTF2 promotes the proliferation, migration, and invasion of HCC cells by regulating Snail transcription, providing a potential therapeutic candidate for patients with HCC.

A Promising Method for Repairing Low-Level Biliary Strictures After Cholecystectomy.

The purpose of this study is to introduce and evaluate a new technique of repairing bile ducts by the tubular gastric wall with a vascularized pedicle. Both the end-to-end bile duct repair and Roux-en-Y hepatoenterostomy have limitations in the treatment of benign bile duct strictures after cholecystectomy. There are no other good choices to manage these cases, especially the bile duct transection injuries or partly missing common bile duct or hepatic duct. Eleven patients with partly missing common bile ducts in the Chinese People's Liberation Army General Hospital between January 2007 and December 2012 were retrospectively analyzed. The study comprised 8 females and 3 males, whose age ranged from 29 to 56 years. All patients underwent successful bile duct repair. The time of operations ranged from 210 minutes to 240 minutes. The maximal blood loss was less than 220 ml. There was no perioperative mortality and no case of gastric fistula. Postoperative complications occurred in 3 patients, including wound infection, bile leakage, and erosive gastritis. All complications were cured by conservative treatment. The mean follow-up time was 42 months. One patient was classified as Terblanche's grade II and 10 patients were classified as Terblanche's grade I. The observations indicate that this technique is a feasible and effective choice to manage low level biliary stricture after cholecystectomy, especially suitable to repair bile duct transection injuries or partly missing common bile duct or hepatic duct.