Aspirin triggers ferroptosis in hepatocellular carcinoma cells through restricting NF-κB p65-activated SLC7A11 transcription.

A number of studies have shown that aspirin, as commonly prescribed drug, prevents the development of hepatocellular carcinoma (HCC). Ferroptosis as a dynamic tumor suppressor plays a vital role in hepatocarcinogenesis. In this study we investigated whether aspirin affected ferroptosis in liver cancer cells. RNA-seq analysis revealed that aspirin up-regulated 4 ferroptosis-related drivers and down-regulated 5 ferroptosis-related suppressors in aspirin-treated HepG2 cells. Treatment with aspirin (4 mM) induced remarkable ferroptosis in HepG2 and Huh7 cells, which was enhanced by the ferroptosis inducer erastin (10 µM). We demonstrated that NF-κB p65 restricted ferroptosis in HepG2 and Huh7 cells through directly binding to the core region of SLC7A11 promoter and activating the transcription of ferroptosis inhibitor SLC7A11, whereas aspirin induced ferroptosis through inhibiting NF-κB p65-activated SLC7A11 transcription. Overexpression of p65 rescued HepG2 and Huh7 cells from aspirin-induced ferroptosis. HCC patients with high expression levels of SLC7A11 and p65 presented lower survival rate. Functionally, NF-κB p65 blocked the aspirin-induced ferroptosis in vitro and in vivo, which was attenuated by erastin. We conclude that aspirin triggers ferroptosis by restricting NF-κB-activated SLC7A11 transcription to suppress the growth of HCC. These results provide a new insight into the mechanism by which aspirin regulates ferroptosis in hepatocarcinogenesis. A combination of aspirin and ferroptosis inducer may provide a potential strategy for the treatment of HCC in clinic.

Oncoprotein HBXIP induces PKM2 via transcription factor E2F1 to promote cell proliferation in ER-positive breast cancer.

We have reported that hepatitis B X-interacting protein (HBXIP, also termed LAMTOR5) can act as an oncogenic transcriptional co-activator to modulate gene expression, promoting breast cancer development. Pyruvate kinase muscle isozyme M2 (PKM2), encoded by PKM gene, has emerged as a key oncoprotein in breast cancer. Yet, the regulatory mechanism of PKM2 is still unexplored. Here, we report that HBXIP can upregulate PKM2 to accelerate proliferation of estrogen receptor positive (ER+) breast cancer. Immunohistochemistry analysis using breast cancer tissue microarray uncovered a positive association between the expression of HBXIP and PKM2. We also discovered that PKM2 expression was positively related with HBXIP expression in clinical breast cancer patients by real-time PCR assay. Interestingly, in ER+ breast cancer cells, HBXIP was capable of upregulating PKM2 expression at mRNA and protein levels in a dose-dependent manner, as well as increasing the activity of PKM promoter. Mechanistically, HBXIP could stimulate PKM promoter through binding to the -779/-579 promoter region involving co-activation of E2F transcription factor 1 (E2F1). In function, cell viability, EdU, colony formation, and xenograft tumor growth assays showed that HBXIP contributed to accelerating cell proliferation through PKM2 in ER+ breast cancer. Collectively, we conclude that HBXIP induces PKM2 through transcription factor E2F1 to facilitate ER+ breast cancer cell proliferation. We provide new evidence for the mechanism of transcription regulation of PKM2 in promotion of breast cancer progression.

Aspirin inhibits the proliferation of hepatoma cells through controlling GLUT1-mediated glucose metabolism.

Aspirin can efficiently inhibit liver cancer growth, but the mechanism is poorly understood. In this study, we report that aspirin modulates glucose uptake through downregulating glucose transporter 1 (GLUT1), leading to the inhibition of hepatoma cell proliferation. Our data showed that aspirin significantly decreased the levels of reactive oxygen species (ROS) and glucose consumption in hepatoma cells. Interestingly, we identified that GLUT1 and HIF1α could be decreased by aspirin. Mechanically, we demonstrated that the -1008/-780 region was the regulatory element of transcriptional factor NF-κB in GLUT1 promoter by luciferase report gene assays. PDTC, an inhibitor of NF-κB, could suppress the expression of GLUT1 in HepG2 and H7402 cells, followed by affecting the levels of ROS and glucose consumption. CoCl2-activated HIF1α expression could slightly rescue the GLUT1 expression inhibited by aspirin or PDTC, suggesting that aspirin depressed GLUT1 through targeting NF-κB or NF-κB/HIF1α signaling. Moreover, we found that GLUT1 was highly expressed in clinical HCC tissues relating to their paired adjacent normal tissues. Importantly, we observed that high level of GLUT1 was significantly correlated with the poor relapse-free survival of HCC patients by analysis of public data. Functionally, overexpression of GLUT1 blocked the PDTC-induced or aspirin-induced inhibition of glucose metabolism in HepG2 cells. Conversely, aspirin failed to work when GLUT1 was stably knocked down in the cells. Administration of aspirin could depress the growth of hepatoma cells through controlling GLUT1 in vitro and in vivo. Thus, our finding provides new insights into the mechanism by which aspirin depresses liver cancer.

miR-511 promotes the proliferation of human hepatoma cells by targeting the 3'UTR of B cell translocation gene 1 (BTG1) mRNA.

Aberrant expression of miR-511 is involved in the development of cancer, but the role of miR-511 in hepatocellular carcinoma (HCC) is not well documented. In this study, we explored the molecular mechanisms of miR-511 in hepatocarcinogenesis. Our results of bioinformatics analysis suggested that B cell translocation gene 1 (BTG1), a member of anti-proliferative gene family, was one of the putative targets of miR-511. The expression levels of miR-511 were significantly higher in 30 clinical HCC tissues than in corresponding peritumor tissues, and were negatively correlated with those of BTG1 in the HCC tissues (r=-0.6105, P<0.01). In human hepatoma cell lines HepG2 and H7402, overexpression of miR-511 dose-dependently inhibited the expression of BTG1, whereas knockdown of miR-511 dose-dependently increased the expression of BTG1. Luciferase reporter gene assays verified that miR-511 targeted the 3'UTR of BTG1 mRNA. In the hepatoma cells, overexpression of miR-511 significantly decreased BTG1-induced G1 phase arrest, which was rescued by overexpression of BTG1. Furthermore, overexpression of miR-511 promoted the proliferation of the hepatoma cells, which was rescued by overexpression of BTG1. Conversely, knockdown of miR-511 inhibited cell proliferation, which was reversed by knockdown of BTG1. In conclusion, miR-511 promotes the proliferation of human hepatoma cells in vitro by targeting the 3'UTR of BTG1 mRNA.

Transanal Tube for the Prevention of Anastomotic Leakage After Rectal Cancer Surgery: A Systematic Review and Meta-analysis.

BACKGROUND: Transanal tubes (TTs) have been used to prevent and reduce anastomotic leakage after rectal cancer surgery. The aim of this review was to investigate the efficacy and safety of the TT. METHODS: A systematic literature search was performed to identify randomized controlled trials and controlled clinical trials assessing the clinical efficacy and safety of TTs in rectal cancer surgery. RESULTS: Seven trials with 1609 participants were included. The TT group had a lower anastomotic leakage rate than the non-transanal tube group [RR 0.38; 95 % confidence interval (CI) 0.25-0.58; P < 0.0001], as well as a lower reoperation rate (RR 0.31; 95 % CI 0.19-0.53; P < 0.0001) and a shorter hospital stay (mean = -2.59 days; 95 % CI -3.69 to -1.49; P < 0.0001). There were no significant differences in mortality between the two groups. CONCLUSION: TT use in rectal cancer surgery is likely to be an effective and safe method of preventing and reducing anastomotic leakage and is associated with a decreased risk of reoperation and faster recovery.

Post-transcriptional modulation of protein phosphatase PPP2CA and tumor suppressor PTEN by endogenous siRNA cleaved from hairpin within PTEN mRNA 3'UTR in human liver cells.

AIM: Increasing evidence shows that mRNAs exert regulatory function along with coding proteins. Recently we report that a hairpin within YAP mRNA 3'UTR can modulate the Hippo signaling pathway. PTEN is a tumor suppressor, and is mutated in human cancers. In this study we examined whether PTEN mRNA 3'UTR contained a hairpin structure that could regulate gene regulation at the post-transcriptional level. METHODS: The secondary structure of PTEN mRNA 3'UTR was analyzed using RNAdraw and RNAstructure. Function of hairpin structure derived from the PTEN mRNA 3'UTR was examined using luciferase reporter assay, RT-PCR and Western blotting. RNA-immunoprecipitation (RIP) assay was used to analyze the interaction between PTEN mRNA and microprocessor Drosha and DGCR8. Endogenous siRNA (esiRNA) derived from PTEN mRNA 3'UTR was identified by RT-PCR and rt-PCR, and its target genes were predicted using RNAhybrid. RESULTS: A bioinformatics analysis revealed that PTEN mRNA contained a hairpin structure (termed PTEN-sh) within 3'UTR, which markedly increased the reporter activities of AP-1 and NF-κB in 293T cells. Moreover, treatment with PTEN-sh (1 and 2 µg) dose-dependently inhibited the expression of PTEN in human liver L-O2 cells. RIP assay demonstrated that the microprocessor Drosha and DGCR8 was bound to PTEN-sh in L-O2 cells, leading to the cleavage of PTEN-sh from PTEN mRNA 3'UTR. In addition, microprocessor Dicer was involved in the processing of PTEN-sh. Interestingly, esiRNA (termed PTEN-sh-3p21) cleaved from PTEN-sh was identified in 293T cells and human liver tissues, which was found to target the mRNA 3'UTRs of protein phosphatase PPP2CA and PTEN in L-O2 cells. Treatment of L-O2 or Chang liver cells with PTEN-sh-3p21 (50, 100 nmol/L) promoted the cell proliferation in dose- and time-dependent manners. CONCLUSION: The endogenous siRNA (PTEN-sh-3p21) cleaved from PTEN-sh within PTEN mRNA 3'UTR modulates PPP2CA and PTEN at the post-transcriptional level in liver cells.

Hepatitis B virus X protein promotes human hepatoma cell growth via upregulation of transcription factor AP2α and sphingosine kinase 1.

AIM: Sphingosine kinase 1 (SPHK1) is involved in various cellular functions, including cell growth, migration, apoptosis, cytoskeleton architecture and calcium homoeostasis, etc. As an oncogenic kinase, SPHK1 is associated with the development and progression of cancers. The aim of this study was to investigate whether SPHK1 was involved in hepatocarcinogenesis induced by the hepatitis B virus X protein (HBx). METHODS: The expression of SPHK1 in hepatocellular carcinoma (HCC) tissue and hepatoma cells were measured using qRT-PCR and Western blot analysis. HBx expression levels in hepatoma cells were modulated by transiently transfected with HBx or psi-HBx plasmids. The SPHK1 promoter activity was measured using luciferase reporter gene assay, and the interaction of the transcription factor AP2α with the SPHK1 promoter was studied with chromatin immunoprecipitation assay. The growth of hepatoma cells was evaluated in vitro using MTT and colony formation assays, and in a tumor xenograft model. RESULTS: A positive correlation was found between the mRNA levels of SPHK1 and HBx in 38 clinical HCC samples (r=+0.727, P<0.01). Moreover, the expression of SPHK1 was markedly increased in the liver cancer tissue of HBx-transgenic mice. Overexpressing HBx in normal liver cells LO2 and hepatoma cells HepG2 dose-dependently increased the expression of SPHK1, whereas silencing HBx in HBx-expressing hepatoma cells HepG2-X and HepG2.2.15 suppressed SPHK1 expression. Furthermore, overexpressing HBx in HepG2 cells dose-dependently increased the SPHK1 promoter activity, whereas silencing HBx in HepG2-X cells suppressed this activity. In HepG2-X cells, AP2α was found to directly interact with the SPHK1 promoter, and silencing AP2α suppressed the SPHK1 promoter activity and SPHK1 expression. Silencing HBx in HepG2-X cells abolished the HBx-enhanced proliferation and colony formation in vitro, and tumor growth in vivo. CONCLUSION: HBx upregulates SPHK1 through the transcription factor AP2α, which promotes the growth of human hepatoma cells.

Does intravenous fish oil benefit patients post-surgery? A meta-analysis of randomised controlled trials.

BACKGROUND AND AIMS: Supplementation of fish oil (FO) containing lipid emulsions has been associated with a reduction in the length of hospital stay, infections and liver dysfunction in patients undergoing major surgery. We carried out a meta-analysis and subgroup analysis to examine randomised clinical trial (RCT)-based evidence of the aforementioned effects. METHODS: Four databases, reference lists and the WHO ICTRP were systematically searched for RCTs to access the clinical efficacy of fish oil-enriched total parenteral nutrition in post-surgery patients. Methodological quality assessment was based on the Cochrane Handbook and GRADE. RESULTS: Twenty-one RCTs were enrolled for meta-analysis. FO was associated with a significant reduction in the length of hospital stay (mean = -2.14 d, 95% CI = -3.02 to -1.27), infections (OR = 0.53, 95% CI = 0.35-0.81), ALT (mean = -6.35 U/L, 95% CI = -11.75 to -0.94), GGT (mean = -11.01 U/L, 95% CI = -20.77 to -1.25) and total bilirubin (mean = -2.06 µmol/L, 95% CI = -3.6 to -0.52), as well as a non-significant change in mortality and postoperative medical cost. The quality of evidence of each clinical outcome was accessed as high. CONCLUSION: FO-enriched lipid emulsions are likely to reduce infections, the length of hospital stay and liver dysfunction without influencing mortality and may be a safe and preferable choice in post-surgery patients. Further well-designed trials should be performed to determine whether FO lipid emulsions reduce mortality in patients undergoing hepatic surgery, especially liver transplantation, and the cost effectiveness of such treatment.

[Clinical observation of preoperative administration of enteral nutrition support in gastric cancer patients at risk of malnutrition].

OBJECTIVE: To evaluate safety and efficacy of preoperative administration of enteral nutrition support in gastric cancer patients at risk of malnutrition. METHODS: A single center randomized controlled clinical trial was performed in 60 gastric cancer patients in West China Hospital from May to October 2012. Thirty patients were given enteral nutrition support(Ensure(R)) manufactured by Abbott Laboratories for ten consecutive days before surgical operation in the treatment group, and 30 patients were given an isocaloric and isonitrogenous homogenized diet in the control group for 10 days as well. The laboratory parameters of nutritional status and hepatorenal function were observed and compared between the two groups on admission, preoperative day 1 and postoperative day 3, respectively. Clinical observations, such as nausea and vomiting, were carried out until patients were discharged. RESULTS: Before the intervention, there were no significant differences in the baseline characteristics between the two groups. The levels of serum albumin [(33.9±5.6) g/L vs. (31.0±5.3) g/L, P<0.05], and hemoglobin[(103.4±7.7) g/L vs.(96.6±10.5) g/L, P<0.01] were significantly improved in the treatment group on postoperative day 3. However, the levels of body mass index, lymphocyte count, liver and renal function, serum glucose, sodium, and potassium were not significantly different between the two groups(all P>0.05). Moreover, two patients with nausea and one with vomiting in each group were found. In clinical observation period, no severe treatment-related adverse event were observed. CONCLUSION: The enteral supplement with Ensure(R) in gastric cancer patients at risk of malnutrition during preoperative period is effective and safe, which is superior to homogenized diet and an appropriate choice for gastric cancer patients with nutritional risk.