MYC-regulated genes involved in liver cell dysplasia identified in a transgenic model of liver cancer

Integrated systematic functional screen and fine-mapping decipher the role and genetic regulation of RPS19 in colorectal cancer development

Despite genome-wide association studies (GWAS) have identified more than 200 risk loci associated with colorectal cancer (CRC), the causal genes or risk variants within these loci and their biological functions remain not fully revealed. Recently, the genomic locus 19q13.2, with the lead SNP rs1800469 was identified as a crucial CRC risk locus in Asian populations. However, the functional mechanism of this region has not been fully elucidated. Here we employed an RNA interfering-based on-chip approach to screen for the genes essential for cell proliferation in the CRC risk locus 19q13.2. Notably, we found that RPS19 exhibited the most significant effect among the identified genes and acted as a critical oncogene facilitating CRC cell proliferation. Subsequently, combining integrative fine-mapping analysis and a large-scale population study consisting of 6027 cases and 6099 controls, we prioritized rs1025497 as a potential causal candidate for CRC risk, demonstrating that rs1025497[A] allele significantly reduced the risk of CRC (OR 0.70, 95% confidence interval = 0.56-0.83, P = 1.12 × 10-6), which was further validated in UK Biobank cohort comprising 5,313 cases and 21,252 controls. Mechanistically, we experimentally elucidated that variant rs1025497 might acted as an allele-specific silencer, inhibiting the expression level of oncogene RPS19 mediated by the transcription suppressive factor HBP1. Taken together, our sturdy unveils the significant role of RPS19 during CRC pathogenesis and delineates its distal regulatory mechanism mediated by rs1025497, advancing our understanding of the etiology of CRC and provided new insights into the personalized medicine of human cancer.

Prediction of clinical prognosis and drug sensitivity in hepatocellular carcinoma through the combination of multiple cell death pathways

Hepatocellular carcinoma (HCC) is the sixth most common malignant tumor, highlighting a significant need for reliable predictive models to assess clinical prognosis, disease progression, and drug sensitivity. Recent studies have highlighted the critical role of various programmed cell death pathways, including apoptosis, necroptosis, pyroptosis, ferroptosis, cuproptosis, entotic cell death, NETotic cell death, parthanatos, lysosome-dependent cell death, autophagy-dependent cell death, alkaliptosis, oxeiptosis, and disulfidptosis, in tumor development. Therefore, by investigating these pathways, we aimed to develop a predictive model for HCC prognosis and drug sensitivity. We analyzed transcriptome, single-cell transcriptome, genomic, and clinical information using data from the TCGA-LIHC, GSE14520, GSE45436, and GSE166635 datasets. Machine learning algorithms were used to establish a cell death index (CDI) with seven gene signatures, which was validated across three independent datasets, showing that high CDI correlates with poorer prognosis. Unsupervised clustering revealed three molecular subtypes of HCC with distinct biological processes. Furthermore, a nomogram integrating CDI and clinical information demonstrated good predictive performance. CDI was associated with immune checkpoint genes and tumor microenvironment components using single-cell transcriptome analysis. Drug sensitivity analysis indicated that patients with high CDI may be resistant to oxaliplatin and cisplatin but sensitive to axitinib and sorafenib. In summary, our model offers a precise prediction of clinical outcomes and drug sensitivity for patients with HCC, providing valuable insights for personalized treatment strategies.

RNA-binding protein RPS7 promotes hepatocellular carcinoma progression via LOXL2-dependent activation of ITGB1/FAK/SRC signaling

BACKGROUND

Metastasis is one of the leading cause contributes to treatment failure and poor prognosis of hepatocellular carcinoma (HCC) patients. The underlying mechanism of HCC metastasis remains to be determined. Although several RNA binding proteins (RBPs) have been found to participate in tumorigenesis and progression of liver cancer, the role of RBPs in HCC patients with extrahepatic metastases is poorly understood.

METHODS

By performing RNA-seq of primary HCC tissues (including HCC with extrahepatic metastasis and those did not develop metastasis), we identified a set of HCC metastasis-associated RBPs candidates. Among which, ribosomal protein S7 (RPS7) was found to be remarkably increased in HCC tissues and be strongly related to HCC poor survival. Overexpression or CRISPR-Cas9-mediated knockout were applied to investigate the role of RPS7 on the metastasis-associated phenotypes of HCC cells. RNA sequencing, RIP, RNA-pull down, dual luciferase reporter assay, nascent RNA capture assay, and RNA decay and so on, were applied to reveal the underlying mechanism of RPS7 induced HCC metastasis.

RESULTS

Gain- and loss- of function analyses revealed that RPS7 promoted HCC cells adhesion, migration and invasion capabilities, as well as lung metastasis. Mechanistically, we uncovered that lysyl oxidase-like 2 (LOXL2) was a critical downstream target of RPS7. RPS7 could stabilize LOXL2 mRNA by binding to AUUUA motifs in the 3155-3375 region of the 3'UTR of LOXL2 mRNA, thus increased LOXL2 expression via elevating LOXL2 mRNA abundance. Further research revealed that LOXL2 could accelerate focal adhesion formation through maintaining the protein stability of ITGB1 and activating ITGB1-mediated FAK/SRC signaling pathway, and thereby contribute to the pro-metastasis effect of RPS7.

CONCLUSIONS

Taken together, our data reveal a novel function of RPS7 in HCC metastasis, also reveal the critical roles of the RPS7/LOXL2/ITGB1 axis in HCC metastasis and shed new light on the exploration of molecular drugs against HCC.

Development of a prognostic model based on anoikis-related genes for predicting clinical prognosis and immunotherapy of hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is the predominant cause of cancer-related mortality worldwide. The majority of HCC patients are diagnosed at advanced stages of the disease, with a high likelihood of metastasis and unfavorable prognosis. Anoikis resistance is a crucial factor contributing to tumor invasion and metastasis, although its specific role in HCC remains unclear. Based on the results of univariate Cox regression and least absolute shrink-age and selection operator (LASSO) analysis, a subset of anoikis-related genes (ARGs) significantly associated with overall survival (OS) was identified. A multivariate Cox regression analysis subsequently identified PDK4, STK11, and TFDP1 as three prognostic ARGs, which were then used to establish a prognostic risk model. Differences in OS caused by risk stratification in HCC patients were demonstrated. The nomogram analysis indicated that the ARGs prognostic signature served as an independent prognostic predictor. In vitro experiments further confirmed the abnormal expression of selected ARGs in HCC. The association between risk scores and OS was further examined through Kaplan-Meier analysis, CIBERSORT analysis, and single-sample gene set enrichment analysis (ssGSEA). This study is a pioneering effort to integrate multiple ARGs and establish a risk-predictive model, providing a unique perspective for the development of personalized and precise therapeutic strategies for HCC.

Gene Expression and Pathway Analysis in Rat Brain and Liver After Exposure to Royal Demolition Explosive (Hexahydro-1,3,5-Trinitro-1,3,5-Triazine)

The nitramine explosive, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is associated with acute and chronic toxicity in mammals and targets both the central nervous system and liver. After a single oral dose of RDX in male rats, the systemic distribution of RDX and the toxicodynamic response was measured using clinical chemistry and Affymetrix Rat Genome® 230 2.0 gene expression arrays, respectively. Nominal doses of 0, 9 and 36 mg/kg pure RDX were administered to animals followed by liver, cerebral cortex, and hippocampus gene expression analysis at 0, 3.5, 24, and 48 hours. RDX quickly entered the liver and brain, increasing up to 24 hours. For the 36 mg/kg dose, RDX was still measurable in liver and brain at 48 hours, but was non-detectible for the 9 mg/kg dose. At 3.5 hours, the time within which most convulsions reportedly occur after RDX ingestion, the hippocampus displayed the highest response for both gene expression and pathways, while the cortex was relatively non-responsive. The top 2 impacted pathways, primarily involved in neurotransmission, were the GABAergic and glutamatergic pathways. High numbers of genes also responded to RDX in the liver with P450 metabolism pathways significantly involved. Compared to the liver, the hippocampus displayed more consistent biological effects across dose and time with neurotransmission pathways predominating. Overall, based on gene expression data, RDX responses were high in both the hippocampus and liver, but were minimal in the cerebral cortex. These results identify the hippocampus as an important target for RDX based on gene expression.

Integrative analysis of the role of BOLA2B in human pan-cancer

Objective: BOLA2B is a recently discovered protein-coding gene. Here, pan-cancer analysis was conducted to determine the expression patterns of BOLA2B and its impact on immune response, gene mutation, and possible molecular biological mechanisms in different tumors, together with investigating its potential usefulness for cancer prognosis. Methods: Data on BOLA2B expression and mutations were downloaded from TCGA and GTEx databases. Clinical survival data from TCGA were used to analyze the prognostic value of BOLA2B. TIMER and ESTIMATE algorithms were used to assess correlations between BOLA2B and tumor-infiltrating immune cells, immune cytokines, and immune scores. Results: BOLA2B was found to be highly expressed at both mRNA and protein levels in multiple tumors, where it was associated with worse overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) in all cancers apart from ovarian cancer. BOLA2B was also found to be positively correlated with copy number variation (CNV), and mutations in TP53, TTN, and MUC16 were found to influence BOLA2B expression. Post-transcriptional modifications, including m5C, m1A, and m6A, were observed to regulate BOLA2B expression in all cancers. Functional analysis showed that BOLA2B was enriched in pathways associated with iron-sulfur cluster formation, mTOR-mediated autophagy, and cell cycle inhibition. Decreased BOLA2B expression induced the proliferation of breast cancer cells and G2/M cell cycle arrest. Conclusion: BOLA2B was found to be highly expressed in malignant tumors and could be used as a biomarker of poor prognosis in multiple cancers. Further investigation into BOLA2B's role and molecular functions in cancer would provide new insights for cancer diagnosis and treatment.

Prognostic Values of BolA Family Member Expression in Hepatocellular Carcinoma

The BolA gene family member (BOLA1-3) plays an important role in regulating normal and pathological biological processes including liver tumorigenesis. However, their expression patterns as prognostic factors in hepatocellular carcinoma (HCC) patients have not to be elucidated. We examined the transcriptional expressions and survival data of BolA family member in patients with HCC from online databases including ONCOMINE, TCGA, UALCAN, Gene Expression Profiling Interactive Analysis (GEPIA), Kaplan-Meier plotter, SurvExpress, cBioPortal, and Exobase. Network molecular interaction views of BolA family members and their neighborhoods were constructed by the IntAct web server. In our research, we had found that the expression levels of BolA /2/3 mRNA were higher in HCC tissue than in normal liver tissues from TGCA databases. Moreover, the BolA family gene expression level is significantly associated with distinct tumor pathological grade, TMN stage, and overall survival (OS). The BolA family can be considered as prognostic risk biomarkers of HCC. A small number of BolA gene-mutated samples were detected in the HCC tissue. IntAct analysis revealed that BolA1/2/3 was closely associated with the GLRX3 expression in HCC, which is implicated in the regulation of the cellular iron homeostasis and tumor growth. Furthermore, prognostic values of altered BolAs and their neighbor GLRX3 gene in HCC patients were validated by SurvExpress analysis. In conclusion, the membrane BolA family identified in this study provides very useful information for the mechanism of hepatic tumorigenesis.

Diet-derived small molecules (nutraceuticals) inhibit cellular proliferation by interfering with key oncogenic pathways: an overview of experimental evidence in cancer chemoprevention

Discouraging statistics of cancer disease has projected an increase in the global cancer burden from 19.3 to 28.4 million incidences annually within the next two decades. Currently, there has been a revival of interest in nutraceuticals with evidence of pharmacological properties against human diseases including cancer. Diet is an integral part of lifestyle, and it has been proposed that an estimated one-third of human cancers can be prevented through appropriate lifestyle modification including dietary habits; hence, it is considered significant to explore the pharmacological benefits of these agents, which are easily accessible and have higher safety index. Accordingly, an impressive embodiment of evidence supports the concept that the dietary factors are critical modulators to prevent, retard, block, or reverse carcinogenesis. Such an action reflects the ability of these molecules to interfere with multitude of pathways to subdue and neutralize several oncogenic factors and thereby keep a restraint on neoplastic transformations. This review provides a series of experimental evidence based on the current literature to highlight the translational potential of nutraceuticals for the prevention of the disease through consumption of enriched diets and its efficacious management by means of novel interventions. Specifically, this review provides the current understanding of the chemopreventive pharmacology of nutraceuticals such as cucurbitacins, morin, fisetin, curcumin, luteolin and garcinol toward their potential as anticancer agents.

Expression profiles and prognostic values of BolA family members in ovarian cancer

BACKGROUND

The BOLA gene family, comprising three members, is mainly involved in regulating intracellular iron homeostasis. Emerging evidence suggests that BolA family member 2 plays a vital role in tumorigenesis and hepatic cellular carcinoma progression. However, there was less known about its role in ovarian cancer.

METHODS

In the present study, we investigated the expression profiles, prognostic roles, and genetic alterations of three BolA family members in patients with ovarian cancer through several public databases, containing Oncomine and Gene Expression Profiling Interactive Analysis, Human Protein Atlas, Kaplan-Meier plotter and cBioPortal. Then, we constructed the protein-protein interaction networks of BOLA proteins and their interactors by using the String database and Cytoscape software. In addition, we performed the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment by the Annotation, Visualization, and Integrated Discovery database. Finally, we explored the mechanisms underlying BolA family members' involvement in OC by using gene set enrichment analysis.

RESULTS

The mRNA and protein expression levels of BOLA2 and BOLA3 were heavily higher in ovarian cancer tissues than in normal ovarian tissues. Dysregulated mRNA expressions of three BolA family members were significantly associated with prognosis in overall or subgroup analysis. Moreover, genetic alterations also occurred in three BolA family members in ovarian cancer. GO analysis indicated that BolA family members might regulate the function of metal ion binding and protein disulfide oxidoreductase activity. Gene set enrichment analysis indicated that BolA family members were mainly associated with oxidative phosphorylation, proteasome, protein export, and glutathione metabolism in ovarian cancer.

CONCLUSION

In brief, our finding may contribute to increasing currently limited prognostic biomarkers and treatment options for ovarian cancer.

Identification and validation of a five-gene prognostic signature for hepatocellular carcinoma

BACKGROUND

ARID1A is a commonly mutated tumor suppressor gene found in all human cancer types, but its clinical significance, oncogenic functions, and relevant mechanisms in hepatocellular carcinoma (HCC) are not well understood.

OBJECTIVE

We aimed to improving the prognosis risk classification of HCC from the perspective of ARID1A mutations.

MATERIALS AND METHODS

We examined the interaction between ARID1A mutations and the overall survival via Kaplan-Meier survival analysis. We used gene set enrichment analysis (GSEA) to elucidate the influence of ARID1A mutations on signaling pathways. A prognostic model was constructed using LASSO and multivariate Cox regression analyses. A receiver operating characteristic (ROC) curve was used to estimate the performance and accuracy of the model.

RESULTS

HCC patients with ARID1A mutations presented poor prognosis. By GSEA, we showed that genes upregulated by reactive oxygen species (ROS) and regulated by MYC were positively correlated with ARID1A mutations. A prognostic signature consisting of 5 genes (SRXN1, LDHA, TFDP1, PPM1G, and EIF2S1) was constructed in our research. The signature showed good performance in predicting overall survival (OS) for HCC patients by internal and external validation.

CONCLUSION

Our research proposed a novel and robust approach for the prognostic risk classification of HCC patients, and this approach may provide new insights to improve the treatment strategy of HCC.

Intracellular partners of fibroblast growth factors 1 and 2 - implications for functions

Fibroblast growth factors 1 and 2 (FGF1 and FGF2) are mainly considered as ligands of surface receptors through which they regulate a broad spectrum of biological processes. They are secreted in non-canonical way and, unlike other growth factors, they are able to translocate from the endosome to the cell interior. These unique features, as well as the role of the intracellular pool of FGF1 and FGF2, are far from being fully understood. An increasing number of reports address this problem, focusing on the intracellular interactions of FGF1 and 2. Here, we summarize the current state of knowledge of the FGF1 and FGF2 binding partners inside the cell and the possible role of these interactions. The partner proteins are grouped according to their function, including proteins involved in secretion, cell signaling, nucleocytoplasmic transport, binding and processing of nucleic acids, ATP binding, and cytoskeleton assembly. An in-depth analysis of the network of these binding partners could indicate novel, non-classical functions of FGF1 and FGF2 and uncover an additional level of a fine control of the well-known FGF-regulated cellular processes.

BolA family member 2 enhances cell proliferation and predicts a poor prognosis in hepatocellular carcinoma with tumor hemorrhage

Objective: BolA family member 2 (BOLA2) is a novel gene highly associated with human hepatocellular carcinoma (HCC) progression. Tumor hemorrhage (TH) acts as a poor marker for HCC patients and is a community affair in the tumor microenvironment. In the present study, we examined a possible association between BOLA2 levels and HCC patients with TH. Methods: The mRNA and protein levels of BOLA2 were determined in two independent cohorts of HCC specimens by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) analysis, respectively. Survival curves and Cox regression models were used to evaluate the prognosis of HCC patients. The CRISPR/Cas9 system was used to knock out BOLA2 in HCC cells, and the functional role of BOLA2 in HCC cell proliferation in vitro and growth in vivo was examined. Results: BOLA2 mRNA expression is significantly higher in HCC tumour tissue than in nontumour tissue. Immunohistochemistry analysis of HCC tissues showed that BOLA2 protein was significantly correlated with TH, a more metastatic phenotype and worse HCC survival. The potential clinical relevance of BOLA2 expression and TH was validated by a Cox regression model. Furthermore, loss-of-function studies determined that BOLA2 plays critical roles in promoting iron overload, tumor growth and TH. Bioinformatics analysis from Gene Expression Profiling Interactive Analysis (GEPIA) revealed that BOLA2 is closely associated with the activation of p62-Keap1 signalling and ATG4B expression. These results were confirmed by immunohistochemistry analysis in HCC tissues. Conclusions: Our results suggest that BOLA2 plays an important role in cancer biology and is an independent predictor of prognosis in HCC.

MicroRNA-543 suppresses liver cancer growth and induces apoptosis via the JAK2/STAT3 signaling pathway

The aim of the present study was to investigate the function of microRNA-543 on liver cancer cell proliferation and apoptosis, and also to identify whether the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway was a direct target of microRNA-543. When compared with paracarcinoma tissue, microRNA-543 expression in tissue samples from patients with liver cancer was identified to be decreased. Furthermore, overall survival of patients with high microRNA-543 expression was increased compared with patients with low microRNA-543 expression. Inhibition of microRNA-543 expression increased cell proliferation and decreased apoptosis of liver cancer cells. It also activated the protein expression of phosphorylated JAK2, phosphorylated STAT3, c-Myc and B-cell lymphoma 2 (Bcl-2) in liver cancer cells. However, activation of microRNA-543 expression in turn decreased cell proliferation and increased apoptosis of liver cancer cells. The results of the present study highlight the pivotal function of microRNA-543 as an inhibitor in liver cancer cell proliferation by observing JAK2/STAT3/c-Myc/Bcl-2 in liver cancer.

Flavonoids Luteolin and Quercetin Inhibit RPS19 and contributes to metastasis of cancer cells through c-Myc reduction

Flavonoids luteolin and quercetin can inhibit growth and metastasis of cancer cells. In our previous report, luteolin and quercetin was shown to block Akt/mTOR/c-Myc signaling. Here, we found luteolin and quercetin reduced protein level and transactivation activity of RPS19 in A431-III cells, which is isolated from parental A431 (A431-P) cell line. Further investigation the inhibitory mechanism of luteolin and quercetin on RPS19, we found c-Myc binding sites on RPS19 promoter. The Akt inhibitor LY294002, mTOR inhibitor rapamycin and c-Myc inhibitor 10058-F4 significantly suppressed RPS19 expression and transactivation activities. Overexpression and knockdown of c-Myc in cancer cells show RPS19 expression was regulated by c-Myc. Furthermore, Knockdown and overexpression of RPS19 was used to analyze of the function of RPS19 in cancer cells. The epithelial-mesenchymal transition (EMT) markers and metastasis abilities of cancer cells were also regulated by RPS19. These data suggest that luteolin and quercetin might inhibit metastasis of cancer cells by blocking Akt/mTOR/c-Myc signaling pathway to suppress RPS19-activated EMT signaling.

Mice Expressing Myc in Neural Precursors Develop Choroid Plexus and Ciliary Body Tumors

Choroid plexus tumors and ciliary body medulloepithelioma are predominantly pediatric neoplasms. Progress in understanding the pathogenesis of these tumors has been hindered by their rarity and lack of models that faithfully recapitulate the disease. Here, we find that endogenous Myc proto-oncogene protein is down-regulated in the forebrain neuroepithelium, whose neural plate border domains give rise to the anterior choroid plexus and ciliary body. To uncover the consequences of persistent Myc expression, MYC expression was forced in multipotent neural precursors (nestin-Cre:Myc), which produced fully penetrant models of choroid plexus carcinoma and ciliary body medulloepithelioma. Nestin-mediated MYC expression in the epithelial cells of choroid plexus leads to the regionalized formation of choroid plexus carcinoma in the posterior domain of the lateral ventricle choroid plexus and the fourth ventricle choroid plexus that is accompanied by loss of multiple cilia, up-regulation of protein biosynthetic machinery, and hydrocephalus. Parallel MYC expression in the ciliary body leads also to up-regulation of protein biosynthetic machinery. Additionally, Myc expression in human choroid plexus tumors increases with aggressiveness of disease. Collectively, our findings expose a select vulnerability of the neuroepithelial lineage to postnatal tumorigenesis and provide a new mouse model for investigating the pathogenesis of these rare pediatric neoplasms.

Trunk mutational events present minimal intra- and inter-tumoral heterogeneity in hepatocellular carcinoma

BACKGROUND & AIMS

According to the clonal model of tumor evolution, trunk alterations arise at early stages and are ubiquitous. Through the characterization of early stages of hepatocarcinogenesis, we aimed to identify trunk alterations in hepatocellular carcinoma (HCC) and study their intra- and inter-tumor distribution in advanced lesions.

METHODS

A total of 151 samples representing the multistep process of hepatocarcinogenesis were analyzed by targeted-sequencing and a single nucleotide polymorphism array. Genes altered in early lesions (31 dysplastic nodules [DNs] and 38 small HCCs [sHCC]) were defined as trunk. Their distribution was explored in: a) different regions of large tumors (43 regions, 21 tumors), and b) different nodules of the same patient (39 tumors, 17 patients). Multinodular lesions were classified as intrahepatic metastases (IMs) or synchronous tumors based on chromosomal aberrations.

RESULTS

TERT promoter mutations (10.5%) and broad copy-number aberrations in chromosomes 1 and 8 (3-7%) were identified as trunk gatekeepers in DNs and were maintained in sHCCs. Trunk drivers identified in sHCCs included TP53 (23%) and CTNNB1 (11%) mutations, and focal amplifications or deletions in known drivers (6%). Overall, TERT, TP53 and CTNNB1 mutations were the most frequent trunk events and at least one was present in 51% of sHCCs. Around 90% of mutations in these genes were ubiquitous among different regions of large tumors. In multinodular HCCs, 35% of patients harbored IMs; 85% of mutations in TERT, TP53 and/or CTNNB1 were retained in primary and metastatic tumors.

CONCLUSIONS

Trunk events in early stages (TERT, TP53, CTNNB1 mutations) were ubiquitous across different regions of the same tumor and between primary and metastatic nodules in >85% of cases. This concept supports the knowledge that single biopsies would suffice to capture trunk mutations in HCC.

LAY SUMMARY

Trunk alterations arise at early stages of cancer and are shared among all malignant cells of the tumor. In order to identify trunk alterations in HCC, we characterized early stages of hepatocarcinogenesis represented by dysplastic nodules and small lesions. Mutations in TERT, TP53 and CTNNB1 genes were the most frequent. Analyses in more advanced lesions showed that mutations in these same genes were shared between different regions of the same tumor and between primary and metastatic tumors, suggesting their trunk role in this disease.

MYC drives overexpression of telomerase RNA (hTR/TERC) in prostate cancer

Telomerase consists of at least two essential elements, an RNA component hTR or TERC that contains the template for telomere DNA addition and a catalytic reverse transcriptase (TERT). While expression of TERT has been considered the key rate-limiting component for telomerase activity, increasing evidence suggests an important role for the regulation of TERC in telomere maintenance and perhaps other functions in human cancer. By using three orthogonal methods including RNAseq, RT-qPCR, and an analytically validated chromogenic RNA in situ hybridization assay, we report consistent overexpression of TERC in prostate cancer. This overexpression occurs at the precursor stage (e.g. high-grade prostatic intraepithelial neoplasia or PIN) and persists throughout all stages of disease progression. Levels of TERC correlate with levels of MYC (a known driver of prostate cancer) in clinical samples and we also show the following: forced reductions of MYC result in decreased TERC levels in eight cancer cell lines (prostate, lung, breast, and colorectal); forced overexpression of MYC in PCa cell lines, and in the mouse prostate, results in increased TERC levels; human TERC promoter activity is decreased after MYC silencing; and MYC occupies the TERC locus as assessed by chromatin immunoprecipitation (ChIP). Finally, we show that knockdown of TERC by siRNA results in reduced proliferation of prostate cancer cell lines. These studies indicate that TERC is consistently overexpressed in all stages of prostatic adenocarcinoma and that its expression is regulated by MYC. These findings nominate TERC as a novel prostate cancer biomarker and therapeutic target. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Regulation of glycosylphosphatidylinositol-anchored proteins and GPI-phospholipase D in a c-Myc transgenic mouse model of hepatocellular carcinoma and human HCC

Recent research implicated glycosylphosphatidylinositol-anchored proteins (GPI-AP) and GPI-specific phospholipase D (GPI-PLD) in the pathogenesis of fatty liver disease and hepatocellular carcinoma (HCC). Given that c-Myc is frequently amplified in HCC, we investigated their regulation in a c-Myc transgenic disease model of liver cancer and HCC patient samples. Whole genome scans defined 54 significantly regulated genes coding for GPI-AP of which 29 and 14 were repressed in expression in transgenic tumors and steatotic human hepatocyte cultures, respectively, to influence lipid-mediated signal transduction, extracellular matrix and immunity pathways. Analysis of gene specific promoter revealed >95% to carry c-Myc binding sites thus establishing a link between c-Myc activity and transcriptional response. Alike, serum GPI-PLD activity was increased 4-fold in transgenic mice; however its tissue activity was reduced by 70%. The associated repression of the serine/threonine phosphatase 2A (PP2A), i.e. a key player of c-Myc proteolysis, indicates co-ordinate responses aimed at impairing tissue GPI-PLD anti-proliferative activities. Translational research identified >4-fold increased GPI-PLD serum protein expression though enzyme activities were repressed by 60% in NASH and HCC patients. Taken collectively, c-Myc influences GPI-AP signaling transcriptionally and posttranslational and represses GPI-AP anti-proliferative signaling in tumors. The findings broaden the perspective of molecular targeted therapies and disease monitoring.

Methylomics of nitroxidative stress on precancerous cells reveals DNA methylation alteration at the transition from in situ to invasive cervical cancer

Epigenetic dysregulation is important in cervical cancer development, but the underlying mechanism is largely unknown. Increasing evidence indicates that DNA methylation is sensitive to changes in microenvironmental factors, such as nitric oxide (NO) in the chronic inflammatory cervix. However, the epigenomic effects of NO in cancer have not been investigated. In this study, we explored the methylomic effects of nitroxidative stress in HPV-immortalized precancerous cells. Chronic NO exposure promoted the acquisition of malignant phenotypes such as cell growth, migration, invasion, and anchorage-independent growth. Epigenetic analysis confirmed hypermethylation of PTPRR. Whole-genome methylation analysis showed BOLA2B, FGF8, HSPA6, LYPD2, and SHE were hypermethylated in cells. The hypermethylation BOLA2B, FGF8, HSPA6, and SHE was confirmed in cervical scrapings from invasive cancer, but not in CIN3/CIS, CIN2 and CIN1 (p=0.019, 0.023, 0.023 and 0.027 respectively), suggesting the role in the transition from in situ to invasive process. Our results reveal that nitroxidative stress causes epigenetic changes in HPV-infected cells. Investigation of these methylation changes in persistent HPV infection may help identify new biomarkers of DNA methylation for cervical cancer screening, especially for precancerous lesions.

Genomics of human fatty liver disease reveal mechanistically linked lipid droplet-associated gene regulations in bland steatosis and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is a common disorder hallmarked by excessive lipid deposits. Based on our recent research on lipid droplet (LD) formation in hepatocytes, we investigated LD-associated gene regulations in NAFLD of different grades, that is, steatosis vs steatohepatitis by comparing liver biopsies from healthy controls (N = 13) and NAFLD patients (N = 102). On average, more than 700 differentially expressed genes (DEGs) were identified of which 146 are mechanistically linked to LD formation. We identified 51 LD-associated DEGs frequently regulated in patient samples (range ≥5 to ≤102) with the liver-receptor homolog-1(NR5A2), that is, a key regulator of cholesterol metabolism being commonly repressed among 100 patients examined. With bland steatosis, notable regulations involved hypoxia-inducible lipid droplet-associated-protein and diacylglycerol-O-acyltransferase-2 renowned for their role in LD-growth. Conversely, nonalcoholic steatohepatitis-associated DEGs coded for epidermal growth factor receptor and TLR4 signaling with decreased expression of the GTPase Rab5 and the lipid phosphohydrolase PPAP2B thus highlighting adaptive responses to inflammation, LDL-mediated endocytosis and lipogenesis, respectively. Studies with steatotic primary human hepatocyte cultures demonstrated induction of LD-associated PLIN2, CIDEC, DNAAF1, whereas repressed expression of CPT1A, ANGPTL4, and PKLR informed on burdened mitochondrial metabolism. Equally, repressed expression of the B-lymphocyte chemoattractant CXCL13 and STAT4 as well as induced FGF21 evidenced amelioration of steatosis-related inflammation. In-vitro/in-vivo patient sample comparisons confirmed C-reactive protein, SOCS3, NR5A2, and SOD2 as commonly regulated. Lastly, STRING network analysis highlighted potential "druggable" targets with PLIN2, CIDEC, and hypoxia-inducible lipid droplet-associated-protein being confirmed by immunofluorescence microscopy. In conclusion, steatosis and steatohepatitis specific gene regulations informed on the pathogenesis of NAFLD to broaden the perspective of targeted therapies.

Interferon-microRNA signalling drives liver precancerous lesion formation and hepatocarcinogenesis

OBJECTIVE

Precancerous lesion, a well-established histopathologically premalignant tissue with the highest risk for tumourigenesis, develops preferentially from activation of DNA damage checkpoint and persistent inflammation. However, little is known about the mechanisms by which precancerous lesions are initiated and their physiological significance.

DESIGN

Laser capture microdissection was used to acquire matched normal liver, precancerous lesion and tumour tissues. miR-484(-/-), Ifnar1(-/-) and Tgfbr2(△hep) mice were employed to determine the critical role of the interferon (IFN)-microRNA pathway in precancerous lesion formation and tumourigenesis. RNA immunoprecipitation (RIP), pull-down and chromatin immunoprecipitation (ChIP) assays were applied to explore the underlying mechanisms.

RESULTS

miR-484 is highly expressed in over 88% liver samples clinically. DEN-induced precancerous lesions and hepatocellular carcinoma were dramatically impaired in miR-484(-/-) mice. Mechanistically, ectopic expression of miR-484 initiates tumourigenesis and cell malignant transformation through synergistic activation of the transforming growth factor-β/Gli and nuclear factor-κB/type I IFN pathways. Specific acetylation of H3K27 is indispensable for basal IFN-induced continuous transcription of miR-484 and cell transformation. Convincingly, formation of precancerous lesions were significantly attenuated in both Tgfbr2(△hep) and Ifnar1(-/-) mice.

CONCLUSIONS

These findings demonstrate a new protumourigenic axis involving type I IFN-microRNA signalling, providing a potential therapeutic strategy to manipulate or reverse liver precancerous lesions and tumourigenesis.

Proteomic identification of potential cancer markers in human urine using subtractive analysis

Urine is an ideal medium in which to focus diagnostic cancer research due to the non-invasive nature and ease of sampling. Many large-scale proteomic studies have shown that urine is unexpectedly complex. We hypothesised that novel diagnostic cancer biomarkers could be discovered using a comparative proteomic analysis of pre-existing data. We assembled a database of 100 published datasets of 5,620 urinary proteins, as well as 46 datasets of 8,620 non-redundant proteins derived from kidney and blood proteome analyses. The data were then used to either subtract or compare molecules from a novel urinary proteome profiling dataset that we generated. We identified 1,161 unique proteins in samples from either cancer-bearing or healthy subjects. Subtractive analysis yielded a subset of 44 proteins that were found uniquely in urine from cancer patients, 30 of which were linked previously to cancer. In conclusion, this approach is useful in discovering novel biomarkers in tissues where unrelated profiling data is available. Only a limited disease-specific novel dataset is required to define new targets or substantiate previous findings. We have shared this discovery platform in the form of our Large Scale Screening Resource database, accessible through the Proteomic Analysis DataBase portal (www.PADB.org).

Long circulating anionic liposomes for hepatic targeted delivery of cisplatin

Anionic liposomes, composed of acetyl glycyrrhetinic acid-poly(ethylene glycol)-stearate, 5-cholestene-3-beta-ol-3-hemisuccinate and phosphatidylcholine, were developed for hepatic targeted delivery of cisplatin.

SerpinB3 and Yap Interplay Increases Myc Oncogenic Activity

SerpinB3 has been recently described as an early marker of liver carcinogenesis, but the potential mechanistic role of this serpin in tumor development is still poorly understood. Overexpression of Myc often correlates with more aggressive tumour forms, supporting its involvement in carcinogenesis. Yes-associated protein (Yap), the main effector of the Hippo pathway, is a central regulator of proliferation and it has been found up-regulated in hepatocellular carcinomas. The study has been designed to investigate and characterize the interplay and functional modulation of Myc by SerpinB3 in liver cancer. Results from this study indicate that Myc was up-regulated by SerpinB3 through calpain and Hippo-dependent molecular mechanisms in transgenic mice and hepatoma cells overexpressing human SerpinB3, and also in human hepatocellular carcinomas. Human recombinant SerpinB3 was capable to inhibit the activity of Calpain in vitro, likely reducing its ability to cleave Myc in its non oncogenic Myc-nick cytoplasmic form. SerpinB3 indirectly increased the transcription of Myc through the induction of Yap pathway. These findings provide for the first time evidence that SerpinB3 can improve the production of Myc through direct and indirect mechanisms that include the inhibition of generation of its cytoplasmic form and the activation of Yap pathway.

RNAi silencing of c-Myc inhibits cell migration, invasion, and proliferation in HepG2 human hepatocellular carcinoma cell line: c-Myc silencing in hepatocellular carcinoma cell

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Although much is known about both the cellular changes that lead to HCC and the etiological agents responsible for the majority of HCC cases, the molecule pathogenesis of HCC is still not well understood. We aimed to determine the effect of c-Myc gene expression on the proliferative, invasive, and migrative capabilities of hepatocellular carcinoma HepG2 cells.

METHODS

A plasmid- based polymerase III promoter system was used to deliver and express short interfering RNA targeting c-Myc to reduce its expression in HepG2 cells. Western blot analysis was used to measure the protein level of c-Myc in HepG2 cells. The effects of c-Myc silencing on the invasion, motility, and proliferation of HepG2 cells were assessed using a Transwell chamber cell migration assay system and a growth curve assay, respectively.

RESULTS

The data showed that plasmids expressing siRNA against c-Myc significantly decreased its expression in HepG2 cells by up to 85%. Importantly, pSilencer-c-Myc transfected cells showed a significantly reduced potential in migration, invasion, and proliferation.

CONCLUSION

C-Myc plays an important role in the development of hepatocellular carcinoma. The data show that down-regulating the c-Myc protein level in HepG2 cells by RNAi could significantly inhibit migration, invasion and proliferation of HepG2 cells. Thus, c-Myc might be a potential therapeutic target for hepatocellular carcinoma.