Blocking hepatocarcinogenesis by a cytochrome P450 family member with female-preferential expression.

OBJECTS: The incidence of hepatocellular carcinoma (HCC) shows an obvious male dominance in rodents and humans. We aimed to identify the key autosomal liver-specific sex-related genes and investigate their roles in hepatocarcinogenesis. DESIGN: Two HCC cohorts (n=551) with available transcriptome and metabolome data were used. Class comparisons of omics data and ingenuity pathway analysis were performed to explore sex-related molecules and their associated functions. Functional assays were employed to investigate roles of the key candidates, including cellular assays, molecular assays and multiple orthotopic HCC mouse models. RESULTS: A global comparison of multiple omics data revealed 861 sex-related molecules in non-tumour liver tissues between female and male HCC patients, which denoted a significant suppression of cancer-related diseases and functions in female liver than male. A member of cytochrome P450 family, CYP39A1, was one of the top liver-specific candidates with significantly higher levels in female vs male liver. In HCC tumours, CYP39A1 expression was dramatically reduced in over 90% HCC patients. Exogenous CYP39A1 significantly blocked tumour formation in both female and male mice and partially reduced the sex disparity of hepatocarcinogenesis. The HCC suppressor role of CYP39A1 did not rely on its known P450 enzyme activity but its C-terminal region, by which CYP39A1 impeded the transcriptional activation activity of c-Myc, leading to a significant inhibition of hepatocarcinogenesis. CONCLUSIONS: The liver-specific CYP39A1 with female-preferential expression was a strong suppressor of HCC development. Strategies to up-regulate CYP39A1 might be promising methods for HCC treatment in both women and men in future.

MiR-125b Loss Activated HIF1α/pAKT Loop, Leading to Transarterial Chemoembolization Resistance in Hepatocellular Carcinoma.

BACKGROUND AND AIMS: Transarterial chemoembolization (TACE) is a standard locoregional therapy for patients with hepatocellular carcinoma (HCC) patients with a variable overall response in efficacy. We aimed to identify key molecular signatures and related pathways leading to HCC resistance to TACE, with the hope of developing effective approaches in preselecting patients with survival benefit from TACE. APPROACH AND RESULTS: Four independent HCC cohorts with 680 patients were used. MicroRNA (miRNA) transcriptome analysis in patients with HCC revealed a 41-miRNA signature related to HCC recurrence after adjuvant TACE, and miR-125b was the top reduced miRNA in patients with HCC recurrence. Consistently, patients with HCC with low miR-125b expression in tumor had significantly shorter time to recurrence following adjuvant TACE in two independent cohorts. Loss of miR-125b in HCC noticeably activated the hypoxia inducible factor 1 alpha subunit (HIF1α)/pAKT loop in vitro and in vivo. miR-125b directly attenuated HIF1α translation through binding to HIF1A internal ribosome entry site region and targeting YB-1, and blocked an autocrine HIF1α/platelet-derived growth factor ß (PDGFß)/pAKT/HIF1α loop of HIF1α translation by targeting the PDGFß receptor. The miR-125b-loss/HIF1α axis induced the expression of CD24 and erythropoietin (EPO) and enriched a TACE-resistant CD24-positive cancer stem cell population. Consistently, patients with high CD24 or EPO in HCC had poor prognosis following adjuvant TACE therapy. Additionally, in patients with HCC having TACE as their first-line therapy, high EPO in blood before TACE was also noticeably related to poor response to TACE. CONCLUSIONS: MiR-125b loss activated the HIF1α/pAKT loop, contributing to HCC resistance to TACE and the key nodes in this axis hold the potential in assisting patients with HCC to choose TACE therapy.

[Effect of lead exposure on gene expression of Fgf3 in zebrafish embryonic development].

OBJECTIVE: To investigate the effect of lead exposure on the gene expression of fibroblast growth factor 3 (Fgf3) in zebrafish embryonic development and the mechanism of lead-induced embryonic developmental toxicity. METHODS: The embryos of zebrafish (wild types A and B) were exposed to lead acetate (PbAc) at the doses of 0, 0.1, 0.5, 2.5, and 12.5 µmol/L separately. Total RNA was extracted from each treatment group of zebrafish embryos at 8, 12, 16, 24, 36, 48, and 72 hours post fertilization (hpf). The total mRNA expression of Fgf3 was measured by real-time quantitative PCR. The spatial expression of Fgf3 in zebrafish embryos was determined by whole-mount in situ hybridization using synthesized Fgf3 RNA probe. RESULTS: The mRNA expression of Fgf3 in each group peaked at 12 hpf (P < 0.01). With the increase in PbAc concentration, the mRNA expression of Fgf3 rose. Compared with the mRNA expression level of Fgf3 in the control group, the relative mRNA expression levels of Fgf3 in the 0.1, 0.5, 2.5, and 12.5 µmol/L PbAc exposure groups were 1.02 ± 0.24, 1.05 ± 0.26, 1.22 ± 0.46, and 1.25 ± 0.38, respectively, and the 2.5 and 12.5 µmol/L PbAc exposure groups showed significantly higher Fgf3 expression than the control group (P < 0.05). The whole-mount in situ hybridization results showed that Fgf3 expression occurred mainly in the head and tail in the early stage of embryonic development and in the midbrain, fin bud, and pharyngeal arch in the middle/late stage of embryonic development; there were the most significant regions and intensities of positive hybridization signals at 12 hpf; but no significant differences were found between the control group and exposure groups in the location and intensity of Fgf3 expression CONCLUSION: Lead exposure can result in the upregulation of Fgf3 expression in zebrafish embryonic development, which might contribute to lead-induced embryonic developmental toxicity.

Practical Strategy to 1,1'-Dideoxygossypol Derivatives from Gossypol and Its Antitumor Activities.

A practical and scalable route for the synthesis of 1,1'-dideoxygossypol from natural polyphenol product gossypol is described. The key step is the successful regioselective deacetylation of hexaacetyl apogossypol 9 and the following reductive removal of hydroxyl groups. The two steps of deacetylation occurred on the different sites under different conditions. The synthetic route follows a simple protection-deprotection strategy, and the yields of each step are over 85%. The total yield of this 9-step synthesis is over 40%, which is much better than the reported total synthesis method. The antitumor results illustrate that 1,1'-hydroxyl groups are not necessary for antitumor activities. In addition, 1,1'-dideoxygossypol has superior aqueous solubility (215 mg/L) compared to gossypol (64 mg/L).

Loss of miR-192-5p initiates a hyperglycolysis and stemness positive feedback in hepatocellular carcinoma.

BACKGROUND: Emerging studies revealed that cancer stem cells (CSCs) possessed peculiar metabolic properties, which however remained largely unknown in hepatocellular carcinoma (HCC). Genetic silencing of liver-abundant miR-192-5p was a key feature for multiple groups of CSC-positive HCCs. We thus aimed to investigate essential metabolic features of hepatic CSCs via using HCCs with miR-192-5p silencing as a model. METHODS: Datasets from two independent HCC cohorts were used. Data integration analyses of miR-192-5p with metabolome and mRNA transcriptome data in HCC Cohort 1 were performed to investigate miR-192-5p related metabolic features, which was further validated in Cohort 2. Cellular and molecular assays were performed to examine whether and how miR-192-5p regulated the identified metabolic features. Co-culture systems consisting of HCC cells and LX2 (human hepatic stellate cell line) or THP1 (human monocyte cell line) were established to explore effects of the identified metabolic properties on stemness features of HCC cells via interacting with co-cultured non-tumor cells. RESULTS: High levels of glycolysis-related metabolites and genes were present in HCCs with low miR-192-5p and CSC-positive HCCs in two independent HCC cohorts. miR-192-5p knockout cells displayed CSC features and miR-192-5p loss led to an enhanced glycolytic phenotype via upregulating three bona fide targets, GLUT1 and PFKFB3 (two glycolytic enzymes) and c-Myc (regulating glycolytic genes' expression). Meanwhile, c-Myc suppressed miR-192-5p transcription, ensuring a low-miR-192-5p/high-c-Myc loop to maintain hyperglycolysis. Moreover, over-produced lactic acid from hyperglycolytic HCC cells stimulated the ERK phosphorylation of co-cultured LX2 and THP1 non-tumor cells partially via NDRG3 and MCT1, which in turn promoted cell malignancy and stemness of HCC cells. Consistently, HCC patients with low level of miR-192-5p in their tumor tissues and high level of NDRG3 or MCT1 in their non-tumor tissues had the shortest overall survival. CONCLUSIONS: In CSC-positive HCCs, miR-192-5p loss enhanced glycolysis and over produced lactate might further increase HCC malignant features via interacting with environmental non-tumor cells.

miR-192-5p Silencing by Genetic Aberrations Is a Key Event in Hepatocellular Carcinomas with Cancer Stem Cell Features.

Various cancer stem cell (CSC) biomarkers have been identified for hepatocellular carcinoma (HCC), but little is known about the implications of heterogeneity and shared molecular networks within the CSC population. Through miRNA profile analysis in an HCC cohort (n = 241) for five groups of CSC+ HCC tissues, i.e., EpCAM+, CD90+, CD133+, CD44+, and CD24+ HCC, we identified a 14-miRNA signature commonly altered among these five groups of CSC+ HCC. miR-192-5p, the top-ranked CSC miRNA, was liver-abundant and -specific and markedly downregulated in all five groups of CSC+ HCC from two independent cohorts (n = 613). Suppressing miR-192-5p in HCC cells significantly increased multiple CSC populations and CSC-related features through targeting PABPC4. Both TP53 mutation and hypermethylation of the mir-192 promoter impeded transcriptional activation of miR-192-5p in HCC cell lines and primary CSC+ HCC. This study reveals the circuit from hypermethylation of the mir-192 promoter through the increase in PABPC4 as a shared genetic regulatory pathway in various groups of primary CSC+ HCC. This circuit may be the driver that steers liver cells toward hepatic CSC cells, leading to hepatic carcinogenesis. SIGNIFICANCE: miR-192-5p and its regulatory pathway is significantly abolished in multiple groups of HCC expressing high levels of CSC markers, which may represent a key event for hepatic carcinogenesis.

Gene signature predictive of hepatocellular carcinoma patient response to transarterial chemoembolization.

Transarterial chemoembolization (TACE) is a commonly used treatment modality in hepatocellular carcinoma (HCC). The ability to identify patients who will respond to TACE represents an important clinical need, and tumor gene expression patterns may be associated with TACE response. We investigated whether tumor transcriptome is associated with TACE response in patients with HCC. We analyzed transcriptome data of treatment-naïve tumor tissues from a Chinese cohort of 191 HCC patients, including 105 patients who underwent TACE following resection with curative intent. We then developed a gene signature, TACE Navigator, which was associated with improved survival in patients that received either adjuvant or post-relapse TACE. To validate our findings, we applied our signature in a blinded manner to three independent cohorts comprising an additional 130 patients with diverse ethnic backgrounds enrolled in three different hospitals who received either adjuvant TACE or palliative TACE. TACE Navigator stratified patients into Responders and Non-Responders which was associated with improved survival following TACE in our test cohort (Responders: 67 months vs Non-Responders: 39.5 months, p<0.0001). In addition, multivariable Cox model demonstrates that TACE Navigator was independently associated with survival (HR: 9.31, 95% CI: 3.46-25.0, p<0.001). In our validation cohorts, the association between TACE Navigator and survival remained robust in both Asian patients who received adjuvant TACE (Hong Kong: 60 months vs 25.6 months p=0.007; Shandong: 61.3 months vs 32.1 months, p=0.027) and European patients who received TACE as primary therapy (Mainz: 60 months vs 41.5 months, p=0.041). These results indicate that a TACE-specific molecular classifier is robust in predicting TACE response. This gene signature can be used to identify patients who will have the greatest survival benefit after TACE treatment and enable personalized treatment modalities for patients with HCC.

Transcriptome integration analysis in hepatocellular carcinoma reveals discordant intronic miRNA-host gene pairs in expression.

Intronic miRNAs, residing in intronic regions of host genes, are thought to be co-transcribed from their host genes and present consistent expression patterns with host genes. Recent studies reported a few intronic miRNAs with discordant expression with their host genes. We therefore aimed to understand the expression pattern of intronic miRNAs and their host genes in hepatocellular carcinoma (HCC) and reveal possible associated molecular mechanisms. Our genome wide integration analysis of miRNA and mRNA transcriptomes, in three dataset from 550 patients with HCC, found that a large amount of miRNA-host gene pairs were discordantly expressed. Consistent results were also revealed in 775 breast cancer patients. Further, most of HCC-related intronic miRNAs were predicted to have distinct upstream regulators and independent proximal promoter signals from host genes. The discordant expression of representative pairs, miR-26s/CTDSPs, was validated experimentally. We have also identified the independent transcriptional start site, promoter signal, and transcriptional factor of miR-26b from its host gene. Collectively, discordant expression of intronic miRNAs and their host genes was relatively ubiquitous and the intronic miRNA "independent transcription" may partially contribute to such a phenotype.