N6-Methyladenosine Modification of ANLN Enhances Hepatocellular Carcinoma Bone Metastasis.

Bones are categorized as the second most prevalent location of extra-hepatic metastasis in Hepatocellular Carcinoma (HCC), which is linked to an extremely poor prognosis due to limited therapeutic options. N6-methyladenosine (m6A) is a prominent modification involved in HCC, but the exact mechanisms on how m6A modifications induce HCC bone metastases (BM) remain unclear. The key modulators responsible for the abundant m6A RNA modification-induced HCC BM was found to be the METTL3 and YTHDF1. The expression of Anillin actin-binding protein (ANLN) was dramatically higher in HCC with BM tissues, and its messenger RNA (mRNA) stability was enhanced via m6A epitranscriptomic regulation by METTL3 and YTHDF1. High METTL3 and YTHDF1 expression along with nuclear ANLN protein was clinically correlated with BM in HCC patients. Furthermore, HCC BM was attributed to over-expression of nuclear ANLN forming a transcriptional complex with SP1 which enhanced KIF2C transcriptional activity to activate the mTORC1 pathway, therefore increased the expression of RANKL and disproportionated RANKL-OPG expression in bone microenvironment leading to malignant neoplasms invade bone tissue. In addition, inhibition of ANLN m6A modification by DZNeP attenuated HCC BM. This data provides meaningful understanding of the modulation and association of m6A epitranscriptomic-regulated BM in HCC, and moreover, defines potentially valuable therapeutic targets.

Antidiabetic treatment improves prognosis after radical resection in hepatocellular carcinoma patients with diabetes mellitus: a retrospective cohort study from 2000 to 2013.

Background: It remains unclear whether diabetic medications, such as metformin and insulin, affect the post-liver resection prognosis of hepatocellular carcinoma (HCC) patients complicated with diabetes mellitus (DM). This study try to find out the prognostic factors in HCC patients with DM and provide a better antidiabetic therapy after liver resection. Methods: Patients presenting with HCC complicated with DM undergoing liver resection were enrolled in this study. They were examined and followed up every 3-6 months after surgery. Patients were divided into the antidiabetic treatment group and no antidiabetic treatment group according to whether they received medications for diabetes or not. Then patients in the antidiabetic treatment group were further divided into insulin group, metformin group, insulin plus metformin group and others group, according to the medications they received. Overall survival (OS) and recurrence-free survival (RFS) were compared among two groups and four subgoups. Comparative and multivariate analyses were performed to investigate the effects of DM medication on the prognosis of these HCC patients, using Cox proportional hazards model. Results: The 1-, 3-, 5-, and 7-year OS rates for the antidiabetic treatment group were 87.5%, 75.5%, 48.7%, and 29.1%, respectively, and for the no antidiabetic treatment group, the OS rates were 85.4%, 57.7%, 33.6%, and 19.1%, respectively (P=0.007). The 1-, 3-, 5-, 7-year RFS rates for the antidiabetic treatment group were 76.4%, 53.5%, 28.5%, and 17.5%, respectively, and for the no antidiabetic treatment group, the RFS rates were 69.5%, 32.5%, 16.5%, and 10.7%, respectively (P=0.001). In subgroup analysis, There was no significant difference in either RFS (P=0.934) nor OS (P=0.412) among the different types of antidiabetic treatment regimens. Cox proportional hazard regression analysis revealed that tumor size (HR: 1.048), tumor number (HR: 1.626), vascular invasion (HR: 2.074, P=0.003), satellite tumor (HR: 1.592), Edmondson classification (HR: 1.468) and antidiabetic treatment (HR: 0.722) were independent prognostic factors of DFS, while tumor size (HR: 1.048), tumor number (HR: 1.779), vascular invasion (HR: 2.545), Edmondson classification (HR: 1.596) and antidiabetic treatment (HR: 0.713) were independent prognostic factors of OS. Conclusions: For HCC patients with DM, antidiabetic treatment should be recommended aggressively in order to improve the surgical outcome, regardless of which antidiabetic drugs are used.

Erratum: MicroRNA-506-3p targets SIRT1 and suppresses AMPK pathway activation to promote hepatic steatosis.

[This corrects the article DOI: 10.3892/etm.2021.10865.].

Decreased Expression of Programmed Death Ligand-L1 by Seven in Absentia Homolog 2 in Cholangiocarcinoma Enhances T-Cell-Mediated Antitumor Activity.

N6-methyladenosine (m6A) has been reported as an important mechanism of post-transcriptional regulation. Programmed death ligand 1 (PD-L1) is a primary immune inhibitory molecule expressed on tumor cells that promotes immune evasion. In addition, seven in absentia homolog 2 (Siah2), a RING E3 ubiquitin ligase, has been involved in tumorigenesis and cancer progression. However, the role of m6A-METTL14-Siah2-PD-L1 axis in immunotherapy remains to be elucidated. In this study, we showed that METTL14, a component of the m6A methyltransferase complex, induced Siah2 expression in cholangiocarcinoma (CCA). METTL14 was shown to enrich m6A modifications in the 3'UTR region of the Siah2 mRNA, thereby promoting its degradation in an YTHDF2-dependent manner. Furthermore, co-immunoprecipitation experiments demonstrated that Siah2 interacted with PD-L1 by promoting its K63-linked ubiquitination. We also observed that in vitro and in vivo Siah2 knockdown inhibited T cells expansion and cytotoxicity by sustaining tumor cell PD-L1 expression. The METTL14-Siah2-PD-L1-regulating axis was further confirmed in human CCA specimens. Analysis of specimens from patients receiving anti-PD1 immunotherapy suggested that tumors with low Siah2 levels were more sensitive to anti-PD1 immunotherapy. Taken together, our results evidenced a new regulatory mechanism of Siah2 by METTL14-induced mRNA epigenetic modification and the potential role of Siah2 in cancer immunotherapy.

Corrigendum: Decreased expression of programmed death ligand-L1 by seven in absentia homolog 2 in cholangiocarcinoma enhances T-cell-mediated antitumor activity.

[This corrects the article DOI: 10.3389/fimmu.2022.845193.].

M6A-mediated up-regulation of LncRNA LIFR-AS1 enhances the progression of pancreatic cancer via miRNA-150-5p/ VEGFA/Akt signaling.

N6-methyladenosine (m6A) modification, the most abundant internal methylation of eukaryotic RNA transcripts, is critically implicated in RNA processing. There is extensive evidence indicating that long non-coding RNAs (lncRNAs) serve as key regulators of oncogenesis and tumor progression in humans. Through prior study has assessed that LIFR-AS1 plays a key role in various kinds of malignant tumors. However, the exact role of m6A induced LIFR-AS1 in pancreatic cancer (PC) and its potential molecular mechanisms remain largely unknown. In this study, we determined that PC cell lines and tumors exhibit increased LIFR-AS1 expression that correlates with larger tumor size, lymph node metastasis, and more advanced TNM stage. Functionally, loss-of-function studies indicated that LIFR-AS1 knockdown decreased the proliferation, migration, and invasion of PC cells in vitro. Mechanistically, we found that METTL3 induced m6A hyper-methylation on the 3' UTR of LIFR-AS1 to enhance its mRNA stability and LIFR-AS1 could directly interact with miR-150-5p, thereby indirectly up-regulating VEGFA expressions within cells. Through rescue experiments, we were able to confirm that the unfavorable impact of LIFR-AS1 knockdown on VEGFA /PI3K/Akt Signaling could be reversed via the inhibition of miR-150-5p expression. Together, these findings indicate that a noval m6A-LIFR-AS1 axis promotes PC progression at least in part via regulation of the miR-150-5p/VEGFA axis, indicating that this regulatory axis may be a viable clinical target for the treatment of PC.

MicroRNA-506-3p targets SIRT1 and suppresses AMPK pathway activation to promote hepatic steatosis.

Nonalcoholic fatty liver disease (NAFLD) is a complex type of liver disease that represents an important global health threat. The mechanistic basis of this disease remains incompletely understood. The present study sought to explore whether microRNA (miR)-506-3p served a functional role in the onset and/or progression of NAFLD. To that end, high levels of glucose were used to treat liver cancer cell lines (HepG2 and Huh7) to model hepatic steatosis, and the expression levels of miR-506-3p and its downstream target genes were assessed. The cells of this hepatic steatosis model were transfected with miR-506-3p mimic molecules to explore the effect of miR-506-3p overexpression on cell viability, target gene expression and AMP-activated protein kinase (AMPK) phosphorylation. Via bioinformatics approaches, sirtuin 1 (SIRT1) was identified as a potential miR-506-3p target gene with relevance in NAFLD, and this interaction was confirmed via luciferase reporter assay. In the hepatic steatosis model of the present study, miR-506-3p expression level was significantly increased, whereas SIRT1 mRNA/protein levels and AMPK phosphorylation levels were markedly decreased. Transfection of the cells with miR-506-3p mimics led to significant SIRT1 downregulation, while miR-506-3p inhibitor molecules exhibited the opposite effect, with similar trends observed in the phosphorylation status of AMPK. These results suggested that miR-506-3p can inhibit SIRT1 expression and associated AMPK phosphorylation in HepG2 and Huh7 cells in an in vitro hepatic steatosis model system. These data indicated that the miR-506-3p/SIRT1/AMPK axis may be valuable as a therapeutic target in patients affected by NAFLD.

LncRNA POT1-AS1 accelerates the progression of gastric cancer by serving as a competing endogenous RNA of microRNA-497-5p to increase PDK3 expression.

BACKGROUND: Gastric cancer (GC) is the most common malignant tumor of the digestive system. Although progress has been reported in terms of treatment, it is still the second leading cause of cancer-related death. Long non-coding RNAs have been shown to play a key role in human cancers in recent investigations. However, the role of POT1-AS1 in GC is still unclear. METHODS: The relative POT1-AS1 level in GC tissues and paracancerous tissues was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The biological function of POT1-AS1 was studied by CCK8 and Transwell assays in vitro experiments. Moreover, the downstream target genes of POT1-AS1 were predicted by bioinformatics. RESULTS: In this study, high POT1-AS1 expression in GC cells was confirmed, and its elevated expression was linked to patients' negative clinicopathological characteristics, as well as shorter disease-free survival (DFS) and overall survival (OS). POT1-AS1 was shown to serve as a competing endogenous RNA (ceRNA) by sponging miR-497-5p to increase PDK3 expression. The impact of POT1-AS1 silencing on GC malignant phenotypes could be reversed by suppressing miR-497-5p or restoring PDK3, according to rescue experiments. CONCLUSIONS: In brief, POT1-AS1 acted as an oncogenic lncRNA in GC, facilitating GC development by affecting the miR-497-5p/PDK3 axis, implying that the POT1-AS1/miR-497-5p/PDK3 axis is a useful target in anticancer therapy.

miR-515-5p suppresses HCC migration and invasion via targeting IL6/JAK/STAT3 pathway.

MicroRNAs (miRNAs) have been identified as critical modulators of cell migration and invasion, which are the major causes of cancer progression including hepatocellular carcinoma (HCC). However, the accurate role of miR-515-5p in HCC is still uncertain. Here, we report that miR-515-5p expression is down-regulated in HCC tissues and cell lines, and associated with absence of capsule formation (p = 0.015)﹑microvascular invasion(p = 0.003)﹑and advantange TNM stage (II-III) (p = 0.014) in HCC patients. Overexpression of miR-515-5p inhibited migration and invasion of HCC cells in vitro and in vivo, while miR-515-5p knockdown has the inverse effect. Moreover, using miRNA databases and dual-luciferase report assay, we find miR-515-5p directly binds to the 3'-untranslated region (3'-UTR) of interleukin 6 (IL6). In addition, the regulatory association between miR-515-5p and the IL-6/Janus kinase (JNK)/signal transducer and activator of transcription-3 (STAT3) signaling pathway was explored. Furthermore, overexpression of miR-515-5p inhibited the activation of the JAK/STAT3 signaling pathway, which was rescued by overexpression of IL-6. The results of the current study indicate that miR-515-5p overexpression may serve an important role in inhibiting migration and invasion of HCC cells via suppression of IL-6/JAK/STAT3 signaling pathway activation. MiR-515-5p may serve as a potential therapeutic target for HCC.

MicroRNA-212-3p inhibits the Proliferation and Invasion of Human Hepatocellular Carcinoma Cells by Suppressing CTGF expression.

MicroRNA-212-3p inhibits several human cancers but its effects on hepatocellular carcinoma (HCC) remain unclear. In this study, we show that miR-212-3p is down-regulated in HCC cell lines and tissues, and correlates with vascular invasion (p = 0.001), and the absence of capsule formation (p = 0.009). We found that miR-212-3p influenced the epithelial to mesenchymal transition (EMT) of HCCLM3 and Huh7 cells. Mechanistically, miR-212-3p repressed cell invasion through the suppression of connective tissue growth factor (CTGF). We therefore validate the anti-HCC effects of miR-212-3p through its ability to suppress CTGF and subsequent EMT.

Temporary Ischemia Time Before Snap Freezing Is Important for Maintaining High-Integrity RNA in Hepatocellular Carcinoma Tissues.

Background: High-throughput transcript sequencing plays an important role in the study of hepatocellular carcinoma (HCC) occurrence and development. High-quality biospecimens, especially high-quality RNA, are the most basic prerequisites for obtaining good transcript sequencing data. Our purpose was to explore the treatment conditions of in vitro ischemic tissue samples that can be used to obtain high-integrity RNA before freezing the samples in liquid nitrogen. Materials and Methods: Postoperative tumor tissues (T) and adjacent normal tissues (AN) from 50 HCC patients were randomly selected from May 5, 2017, to June 15, 2017. Postoperative tissue specimens from each HCC patient were stratified by tissue type (T or AN), ischemia time (minutes), and ischemia temperature (°C) into 16 groups: T-4°C-15 minutes, T-4°C-30 minutes, T-4°C-60 minutes, T-4°C-120 minutes, T-24°C-15 minutes, T-24°C-30 minutes, T-24°C-60 minutes, T-24°C-120 minutes, AN-4°C-15 minutes, AN-4°C-30 minutes, AN-4°C-60 minutes, AN-4°C-120 minutes, AN-24°C-15 minutes, AN-24°C-30 minutes, AN-24°C-60 minutes, and AN-24°C-120 minutes. RNA integrity was detected by RNA integrity number (RIN) and 1% agarose gel electrophoresis. Results: At an ischemia temperature of 4°C and ischemia time of >30 minutes, the RIN of T began to decrease. RIN also gradually decreased in T at an ischemia temperature of 4°C and in both T and AN at an ischemia temperature of 24°C for ischemia times 15, 30, 60, and 120 minutes. For an ischemia time ≤15 minutes and ischemia temperature 4°C or 24°C, the RINs of T and AN were significantly different. Furthermore, at ischemia temperature 4°C and ischemia time 30 and 60 minutes or ischemia temperature 24°C and ischemia time 30 minutes, the RIN of T was higher compared with AN. However, there was no significant difference in RIN between T and AN under other treatment conditions. Conclusions: Tissue quality is adversely affected by ischemia time and ischemia temperature. Therefore, temporary ischemia time (≤15 minutes) before snap freezing is key for maintaining high-integrity RNA in HCC tissues.

MicroRNA-197-3p acts as a prognostic marker and inhibits cell invasion in hepatocellular carcinoma.

MicroRNAs (miRNAs) serve an important regulatory role in carcinogenesis and cancer progression. Aberrant expression of miR-197-3p has been reported in various human malignancies. However, the role of miR-197-3p in the progression and prognosis of hepatocellular carcinoma (HCC) remains unknown. The present study demonstrated that miR-197-3p was downregulated in HCC tissues and that the low level of miR-197-3p expression in HCC tumours correlated with aggressive clinicopathological characteristics; thus, miR-197-3p may serve as a predictor for poor prognosis in patients with HCC. Additionally, miR-197-3p markedly inhibited the metastasis of HCC cells in vitro and in vivo. Bioinformatics analysis further identified zinc finger protein interacted with K protein 1 (ZIK1) as a novel target of miR-197-3p in HCC cells. These findings suggest that miR-197-3p may regulate the survival of HCC cells, partially through the downregulation of ZIK1. Therefore, the miR-197-3p/ZIK1 axis may serve as a novel therapeutic target in patients with HCC.

MiR-494-3p promotes PI3K/AKT pathway hyperactivation and human hepatocellular carcinoma progression by targeting PTEN.

Recent studies have shown that miR-494-3p is oncogene and has a central role in many solid tumors; however, the role of miR-494-3p in the progression and prognosis of hepatocellular carcinoma (HCC) remains unknown. In this study, it was found that miR-494-3p was up-regulated in HCC tissues. The high level of miR-494-3p in HCC tumors was correlated with aggressive clinicopathological characteristics and predicted poor prognosis in HCC patients. Functional study demonstrated that miR-494-3p significantly promoted HCC cell metastasis in vitro and vivo. Since phosphoinositide 3-kinase/protein kinase-B (PI3K/AKT) signaling is a basic oncogenic driver in HCC, a potential role of miR-494-3p was explored as well as its target genes in PI3K/AKT activation. Of all the predicted target genes of miR-494-3p, the tumor-suppressor phosphatase and tensin homolog (PTEN) were identified. In conclusion, the data we collected could define an original mechanism of PI3K/AKT hyperactivation and sketch the regulatory role of miR-494-3p in suppressing the expression of PTEN. Therefore, targeting miR-494-3p could provide an effective therapeutic method for the treatment of the disease.