Uridine-cytidine kinase 2 upregulation predicts poor prognosis of hepatocellular carcinoma and is associated with cancer aggressiveness

PET imaging of hepatocellular carcinoma with [124I]IV-14

BACKGROUND

Currently, positron emission tomography (PET) plays no clear role in clinical imaging and management of hepatocellular carcinoma (HCC). New radiotracers for new target(s) are needed for PET imaging of HCC. Uridine-cytidine kinase 2 (UCK2) is a rate-limiting enzyme of the pyrimidine salvage synthesis pathway to phosphorylate uridine and cytidine. Studies have demonstrated that UCK2 is overexpressed in many types of solid cancers including HCC and is associated with the poor prognosis and proliferation of HCC. This study reported PET imaging using a UCK2-specific radiotracer with a clinically relevant anima model of spontaneously occurring HCC in the woodchucks.

METHODS

This study used 3'-(E)-(2-iodovinyl) uridine (IV-14), which is derived from a UCK2-selective antitumor agent 3'-(Ethynyl)uridine (EUrd), a cytotoxic ribonucleoside analogs of uridine. By radiolabeling IV-14 with Iodine-124 (124I), a UCK2-specific radiotracer [124I]IV-14 was obtained for PET imaging of UCK2. A naturally occurring woodchuck model of HCC following chronic viral hepatitis infection was used for PET imaging. Potassium iodide (KI) was tested in one of the three animals to block possible uptake of free 124I from de-iodination of [124I]IV-14.

RESULTS

We confirmed that UCK2 expression is higher in the woodchuck model of HCC than in the surrounding hepatic tissue, similar to human UCK2 that is highly expressed in human HCC. PET imaging with [124I]IV-14 showed a strong uptake in woodchuck HCC with low background uptake at one-hour post-injection. De-iodination did not seem to be an issue for PET imaging.

CONCLUSION

Our results demonstrate that UCK2 is a viable target for imaging HCC and has the potential for targeted endoradiotherapy of HCC.

Uridine-cytidine kinase 2 is correlated with immune, DNA damage repair and promotion of cancer stemness in pan-cancer

Background

UCK2 (Uridine-Cytidine Kinase 2) is a promising prognostic marker for malignant tumors, but its association with immune infiltration and cancer stemness in pan-cancer remains to be fully understood. we find that gene UCK2 is closed related to RNA stemness scores (RNAss) and DNA stemness scores (DNAss), which is measured the tumor stemness. We also discover an association between UCK2 expression and immune cells by CIBERSORT algorithm, ESTIMATE algorithm and ssGSEA algorithm, especially, related to T cell, monocytes, mast cells, and macrophages. This study aims to shed light on the role and possible mechanism of UCK2 in pan-cancer.

Methods

We used the R programming language for pan-cancer bulk sequencing data analysis, which were obtained from the University of California, Santa Cruz (UCSC) datasets. UCSC database is a very useful for explore data from TCGA and other cancer genomics datasets, The data we explored at the UCK2 transcriptome level came from TCGA data in the UCSC database. We explored differential UCK2 expression between tumor and normal samples. Immunohistochemistry (IHC) was utilized to validate the expression of UCK2 in different types cancers using tumor tissue chips. The correlations of UCK2 with prognosis, genetic instability, DNA repair, cancer stem cell characteristics, and immune cell infiltration were investigated. Furthermore, single-cell datasets, acquired from the Gene Expression Omnibus (GEO) database, were used to validate the relationship between UCK2 and immune cells. GEO is a famous public genomics database supporting freely disseminates microarray data. Finally, we analyzed the correlation between UCK2 and drug sensitivity.

Results

UCK2 expression was observed to be high in most cancers and was remarkably related to the prognosis of pan-cancers. We found that the increased UCK2 expression was associated with higher genetic instability. Additionally, positive relationships were observed between UCK2 expression and mismatch repair genes, homologous recombination repair genes, and cancer stemness across different cancer types. There were significant correlations between UCK2 and T cells, monocytes, mast cells, and macrophages. Moreover, as expected, the immune checkpoint human leucocyte antigen (HLA) was found to be negatively related to UCK2. Similarly, UCK2 was also observed to have a negative association with major histocompatibility complex (MHC) genes. We noted that UCK2 had significant correlations with the sensitivity to various anti-cancer drug.

Conclusion

We have observed that UCK2 plays pivotal roles in prognosis and tumor immunity, and it is associated with DNA repair and cancer stemness. The UCK2 gene exhibits a strong correlation with the immune checkpoints HLA. This study highlights its potential impact on drug sensitivity.

UCK2 promotes intrahepatic cholangiocarcinoma progression and desensitizes cisplatin treatment by PI3K/AKT/mTOR/autophagic axis

Intrahepatic cholangiocarcinoma (iCCA) is a highly aggressive tumor with extremely poor prognosis due to the low resection rate, high recurrence rate and drug resistance. Uridine-cytidine kinase 2 (UCK2) is proved to promote progression and drug resistance of various carcinomas by regulating pyrimidine metabolism. However, the role of UCK2 in progression and drug resistance of iCCA was largely unclear. Gene expression matrices were obtained from public database and were verified by qRT-PCR using tumor sample from Sun Yat-sen University Cancer Center. Knockdown and overexpression of UCK2 were used to evaluate the effects of UCK2 on carcinogenesis and cisplatin response in iCCA. CCK8-kit assays and plate clone formation assays were performed to detect the effect of UCK2 on proliferative activity of tumor cells. Western blotting was performed to investigate protein level of UCK2 and the relevant biomarkers of PI3K/AKT/mTOR/autophagic axis. Cell migration and invasion were assessed by using wound-healing and transwell assays. UCK2 expression was detected elevated in iCCA tissues compared with adjacent normal tissues. Biologically, overexpression of UCK2 can promote proliferation of iCCA cells, and desensitizes iCCA to cisplatin in both in vivo and in vitro models. Mechanistically, UCK2 promote iCCA progression and cisplatin resistance through inhibition of autophagy by activating the PI3K/AKT/mTOR signaling pathway. Clinically, higher UCK2 expression in iCCA tumor was associated with aggressive tumor features, poorer survival and lower sensitivity of chemotherapy. UCK2 promotes iCCA progression and desensitizes cisplatin treatment by regulating PI3K/AKT/mTOR/autophagic axis. UCK2 exhibited potential as a biomarker in predicting prognosis and drug sensitivity of iCCA patients.

Reprogramming of pyrimidine nucleotide metabolism supports vigorous cell proliferation of normal and malignant T cells

Adult T-cell leukemia/lymphoma (ATL) is triggered by infection with human T-cell lymphotropic virus-1 (HTLV-1). Here, we describe the reprogramming of pyrimidine biosynthesis in both normal T cells and ATL cells through regulation of uridine-cytidine kinase 2 (UCK2), which supports vigorous proliferation. UCK2 catalyzes the monophosphorylation of cytidine/uridine and their analogues during pyrimidine biosynthesis and drug metabolism. We found that UCK2 was overexpressed aberrantly in HTLV-1-infected T cells but not in normal T cells. T-cell activation via T-cell receptor (TCR) signaling induced expression of UCK2 in normal T cells. Somatic alterations and epigenetic modifications in ATL cells activate TCR signaling. Therefore, we believe that expression of UCK2 in HTLV-1-infected cells is induced by dysregulated TCR signaling. Recently, we established azacitidine-resistant (AZA-R) cells showing absent expression of UCK2. AZA-R cells proliferated normally in vitro, whereas UCK2 knockdown inhibited ATL cell growth. Although uridine and cytidine accumulated in AZA-R cells, possibly because of dysfunction of pyrimidine salvage biosynthesis induced by loss of UCK2 expression, the amount of UTP and CTP was almost the same as in parental cells. Furthermore, AZA-R cells were more susceptible to an inhibitor of dihydroorotic acid dehydrogenase, which performs the rate-limiting enzyme of de novo pyrimidine nucleotide biosynthesis, and more resistant to dipyridamole, an inhibitor of pyrimidine salvage biosynthesis, suggesting that AZA-R cells adapt to UCK2 loss by increasing de novo pyrimidine nucleotide biosynthesis. Taken together, the data suggest that fine-tuning pyrimidine biosynthesis supports vigorous cell proliferation of both normal T cells and ATL cells.

CircUCK2 promotes hepatocellular carcinoma development by upregulating UCK2 in a mir-149-5p-dependent manner

BACKGROUND

Circular RNAs (circRNAs) participate in the regulation of Hepatocellular Carcinoma (HCC) progression. The objective of this study was to explore the function and mechanism of circUCK2 in HCC development.

METHODS

The RNA levels of circUCK2, miR-149-5p and uridine-cytidine kinase 2 (UCK2) were examined by quantitative real-time polymerase chain reaction (qRT-PCR). EdU incorporation assay and colony formation assay were respectively performed to analyze cell proliferation and colony formation. Wound healing assay and transwell assay were conducted for cell migration and invasion. Flow cytometry was used for cell apoptosis analysis. Western blot assay was conducted to determine the protein levels of E-cadherin, N-cadherin, matrix metallopeptidase 9 (MMP-9) and UCK2. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull-down assay were conducted to confirm the interaction between miR-149-5p and circUCK2 or UCK2. The xenograft model was established to explore the role of circUCK2 in tumor growth in vivo.

RESULTS

CircUCK2 level was elevated in HCC, and circUCK2 depletion suppressed HCC cell proliferation, colony formation, migration and invasion and accelerated cell apoptosis. Mechanistically, circUCK2 could positively modulate UCK2 expression by interacting with miR-149-5p. Furthermore, the repressive effects of circUCK2 knockdown on the malignant behaviors of HCC cells were alleviated by UCK2 overexpression or miR-149-5p inhibition. The promoting effects of circUCK2 overexpression on HCC cell malignancy were alleviated by UCK2 silencing or miR-149-5p introduction. Additionally, circUCK2 knockdown hampered tumor growth in vivo.

CONCLUSION

CircUCK2 contributed to HCC malignant progression in vitro and in vivo via targeting miR-149-5p/UCK2 axis, demonstrating that circUCK2 might be a novel therapeutic target for HCC.

Integrative Analyses of Pyrimidine Salvage Pathway-Related Genes Revealing the Associations Between UPP1 and Tumor Microenvironment

Background

The pyrimidine salvage pathway plays a critical role in tumor progression and patient outcomes. The roles of pyrimidine salvage pathway-related genes (PSPGs) in cancer, however, are not fully understood. This study aims to depict the characteristics of PSPGs across various cancers.

Methods

An integrative pan-cancer analysis of six PSPGs (CDA, UCK1, UCK2, UCKL1, UPP1, and UPP2) was conducted using TCGA data, single-cell RNA sequencing datasets, and patient samples. Single-cell transcriptome analysis and RT-qPCR were used to validate the relation between UPP1 and cytokines. Flow cytometry was performed to validate the role of UPP1 in immune checkpoint regulation. The correlation between UPP1 and tumor associated neutrophils (TAN) were investigated and validated by single-cell transcriptome analysis and tissue microarrays (TMAs).

Results

PSPGs showed low mutation rates but significant copy number variations, particularly amplifications in UCKL1, UPP1, and UCK2 across various cancers. DNA methylation patterns varied, with notable negative correlations between methylation and gene expression in UPP1. PSPGs were broadly up-regulated in multiple cancers, with correlations to clinical staging and prognosis. Proteomic data further confirmed these findings. Functional analysis revealed PSPGs' associations with tumor proliferation, metastasis, and various signaling pathways. UPP1 showed strong correlations with the tumor microenvironment (TME), particularly with cytokines, immune checkpoints, and various immune cells. Single-cell transcriptome analysis confirmed these associations, highlighting UPP1's influence on cytokine expression and immune checkpoint regulation. In esophageal squamous cell carcinoma (ESCC), UPP1-high tumor cells were significantly associated with immunosuppressive cells in the TME. Spatial analysis using TMAs revealed that UPP1+ tumor cells were predominantly located at the invasive margin and closely associated with neutrophils, correlating with poorer patient prognosis.

Conclusion

Our study depicted the multi-dimensional view of PSPGs in cancer, with a particular focus on UPP1's role in the TME. Targeting UPP1 holds promise as a potential strategy for cancer therapy.

Uridine-cytidine kinase 2 potentiates the mutagenic influence of the antiviral β-d-N4-hydroxycytidine

Molnupiravir (EIDD-2801) is an antiviral that received approval for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection. Treatment of bacteria or cell lines with the active form of molnupiravir, β-d-N4-hydroxycytidine (NHC, or EIDD-1931), induces mutations in DNA. Yet these results contrast in vivo genotoxicity studies conducted during registration of the drug. Using a CRISPR screen, we found that inactivating the pyrimidine salvage pathway component uridine-cytidine kinase 2 (Uck2) renders cells more tolerant of NHC. Short-term exposure to NHC increased the mutation rate in a mouse myeloid cell line, with most mutations being T:A to C:G transitions. Inactivating Uck2 impaired the mutagenic activity of NHC, whereas over-expression of Uck2 enhanced mutagenesis. UCK2 is upregulated in many cancers and cell lines. Our results suggest differences in ribonucleoside metabolism contribute to the variable mutagenicity of NHC observed in cancer cell lines and primary tissues.

Targeting uridine-cytidine kinase 2 induced cell cycle arrest through dual mechanism and could improve the immune response of hepatocellular carcinoma

BACKGROUND

Pyrimidine metabolism is critical for tumour progression. Uridine-cytidine kinase 2 (UCK2), a key regulator of pyrimidine metabolism, is elevated during hepatocellular carcinoma (HCC) development and exhibits carcinogenic effects. However, the key mechanism of UCK2 promoting HCC and the therapeutic value of UCK2 are still undefined. The aim of this study is to investigate the potential of UCK2 as a therapeutic target for HCC.

METHODS

Gene expression matrices were obtained from public databases. RNA-seq, co-immunoprecipitation and RNA-binding protein immunoprecipitation were used to determine the mechanism of UCK2 promoting HCC. Immune cell infiltration level and immune-related functional scores were evaluated to assess the link between tumour microenvironment and UCK2.

RESULTS

In HCC, the expression of UCK2 was upregulated in part by TGFβ1 stimulation. UCK2 promoted cell cycle progression of HCC by preventing the degradation of mTOR protein and maintaining the stability of PDPK1 mRNA. We also identified UCK2 as a novel RNA-binding protein. Downregulation of UCK2 induced cell cycle arrest and activated the TNFα/NFκB signalling pathway-related senescence-associated secretory phenotype to modify the tumour microenvironment. Additionally, UCK2 was a biomarker of the immunosuppressive microenvironment. Downregulated UCK2 induced a secretory phenotype, which could improve the microenvironment, and decreased UCK2 remodelling metabolism could lower the resistance of tumour cells to T-cell-mediated killing.

CONCLUSIONS

Targeting UCK2 inhibits HCC progression and could improve the response to immunotherapy in patients with HCC. Our study suggests that UCK2 could be an ideal target for HCC.

Effects of PAMK on lncRNA, miRNA, and mRNA expression profiles of thymic epithelial cells

Polysaccharides from Atractylodes macrocephala Koidz (PAMK) can promote the proliferation of thymocytes and improve the body's immunity. However, the effect of PAMK on thymic epithelial cells has not been reported. Studies have shown that miRNAs and lncRNAs are key factors in regulating cell proliferation. In this study, we found that PAMK could promote the proliferation of mouse medullary thymic epithelial cell line 1 (MTEC1) cells through CCK-8 and EdU experiments. To further explore its mechanism, we detected the effect of PAMK on the expression profiles of lncRNAs, miRNAs, and mRNAs in MTEC1 cells. The results showed that PAMK significantly affected the expression of 225 lncRNAs, 29 miRNAs, and 800 mRNAs. Functional analysis showed that these differentially expressed genes were significantly enriched in cell cycle, cell division, NF-kappaB signaling, apoptotic process, and MAPK signaling pathway. Finally, we used Cytoscape to visualize lncRNA-miRNA-mRNA(14 lncRNAs, 17 miRNAs, 171 mRNAs) networks based on ceRNA theory. These results suggest that lncRNAs and miRNAs may be involved in the effect of PAMK on the proliferation of MTEC1 cells, providing a new research direction for exploring the molecular mechanism of PAMK promoting the proliferation of thymic epithelial cells.

The Metabolic and Non-Metabolic Roles of UCK2 in Tumor Progression

Enhanced nucleoside metabolism is one of the hallmarks of cancer. Uridine-cytidine kinase 2 (UCK2) is a rate-limiting enzyme of the pyrimidine salvage synthesis pathway to phosphorylate uridine and cytidine to uridine monophosphate (UMP) and cytidine monophosphate (CMP), respectively. Recent studies have shown that UCK2 is overexpressed in many types of solid and hematopoietic cancers, closely associates with poor prognosis, and promotes cell proliferation and migration in lung cancer and HCCs. Although UCK2 is thought to catalyze sufficient nucleotide building blocks to support the rapid proliferation of tumor cells, we and other groups have recently demonstrated that UCK2 may play a tumor-promoting role in a catalytic independent manner by activating oncogenic signaling pathways, such as STAT3 and EGFR-AKT. By harnessing the catalytic activity of UCK2, several cytotoxic ribonucleoside analogs, such as TAS-106 and RX-3117, have been developed for UCK2-mediated cancer chemotherapy. Moreover, we have demonstrated that the concurrent targeting of the catalytic dependent and independent features of UCK2 could synergistically inhibit tumor growth. These findings suggest that UCK2 may serve as a potential therapeutic target for cancer treatment. In this mini-review, we introduced the genomic localization and protein structure of UCK2, described the role of UCK2 in tumor development, discussed the application of UCK2 in anti-tumor treatment, and proposed concurrent targeting of the catalytic and non-catalytic roles of UCK2 as a potential therapeutic strategy for cancer treatment.

Exploration of a Novel Prognostic Nomogram and Diagnostic Biomarkers Based on the Activity Variations of Hallmark Gene Sets in Hepatocellular Carcinoma

Background

The initiation and progression of tumors were due to variations of gene sets rather than individual genes. This study aimed to identify novel biomarkers based on gene set variation analysis (GSVA) in hepatocellular carcinoma.

Methods

The activities of 50 hallmark pathways were scored in three microarray datasets with paired samples with GSVA, and differential analysis was performed with the limma R package. Unsupervised clustering was conducted to determine subtypes with the ConsensusClusterPlus R package in the TCGA-LIHC (n = 329) and LIRI-JP (n = 232) cohorts. Differentially expressed genes among subtypes were identified as initial variables. Then, we used TCGA-LIHC as the training set and LIRI-JP as the validation set. A six-gene model calculating the risk scores of patients was integrated with the least absolute shrinkage and selection operator (LASSO) and stepwise regression analyses. Kaplan–Meier (KM) and receiver operating characteristic (ROC) curves were performed to assess predictive performances. Multivariate Cox regression analyses were implemented to select independent prognostic factors, and a prognostic nomogram was integrated. Moreover, the diagnostic values of six genes were explored with the ROC curves and immunohistochemistry.

Results

Patients could be separated into two subtypes with different prognoses in both cohorts based on the identified differential hallmark pathways. Six prognostic genes (ASF1A, CENPA, LDHA, PSMB2, SRPRB, UCK2) were included in the risk score signature, which was demonstrated to be an independent prognostic factor. A nomogram including 540 patients was further integrated and well-calibrated. ROC analyses in the five cohorts and immunohistochemistry experiments in solid tissues indicated that CENPA and UCK2 exhibited high and robust diagnostic values.

Conclusions

Our study explored a promising prognostic nomogram and diagnostic biomarkers in hepatocellular carcinoma.

UCK2 regulated by miR-139-3p regulates the progression of hepatocellular carcinoma cells

Objective: This study mainly explores how UCK2 impacts the progression of hepatocellular carcinoma (HCC). Methods: Mature miRNA and mRNA expression data along with the clinical data of HCC were provided by The Cancer Genome Atlas to mine differentially expressed miRNAs and mRNAs. Expression levels of UCK2 and miR-139-3p in HCC were tested through quantitative real-time PCR. How UCK2 and miR-139-3p impacted HCC cell activities were detected by Transwell, wound healing and cell proliferation approaches. Whether miR-139-3p could bind to UCK2 was detected by dual-luciferase assay. Results: This investigation found evidently high levels of UCK2 in both HCC tissue and cells and its marked association with poor prognosis. Overexpression of UCK2 could significantly promote the behaviors of HCC cells. In addition, poorly expressed miR-139-3p was inversely associated with UCK2. Dual-luciferase method also proved the association. The rescue experiment showed that miR-139-3p regulated cell behaviors in HCC through targeting UCK2. Conclusion: Highly expressed UCK2 was mediated by miR-139-3p to modulate cell behaviors in HCC. It is assumed that UCK2 is a possible target of HCC for cancer therapy purposes.

METTL3-induced UCK2 m6A hypermethylation promotes melanoma cancer cell metastasis via the WNT/β-catenin pathway

Background

Melanoma is a highly aggressive, malignant skin tumor with a statistically high mortality rate. N6-methyladenosine (m⁶A) modification is involved in a variety of biological processes, including tumorigenesis. m⁶A modifications regulate the fate and functions of RNA, such as mRNA stability, nuclear processing, transport, localization, translation, primary microRNA (miRNA) processing, and RNA-protein interactions. Several members (including METTL3, METTL14, FTO, ALKBH5, and YTHDF2) are actively involved in a variety of human cancers. However, the basic mechanism of the involvement of uridine cytidine kinase 2 (UCK2) in melanoma metastasis has not been studied. UCK2 is upregulated in a variety of malignancies. However, the complex molecular mechanisms and therapeutic effects of UCK2 in melanoma remain unclear.

Methods

The expression of UCK2 was evaluated by qRT-PCR. The effects of UCK2 on the biological characteristics of PC cells were investigated on the basis of loss-of-function analyses. Immunoprecipitation-qPCR (MeRIP-qPCR) was performed to identify the m⁶A targeted effect of UCK2 in melanoma cancer.

Results

Based on the bioinformatics analysis in this study, up-regulation of UCK2 could be essential in melanoma cancer, and associated with poor survival. Furthermore, the m⁶A modification regulated by METTL3 led to UCK2 increased messenger RNA (mRNA) stability in melanoma cancer. Functional and mechanistic experiments indicated that UCK2 enhanced the metastasis of melanoma cancer cells through the WNT/β-catenin pathway.

Conclusion

In this study, we found that m⁶A-METTL3 axis induced abnormal UCK2 expression plays a role in melanoma metastasis by enhancing the Wnt/β-catenin pathway, which may provide new clues for melanoma metastasis. It also provides a potential target for the prevention and treatment of melanoma.

DTYMK Expression Predicts Prognosis and Chemotherapeutic Response and Correlates with Immune Infiltration in Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) is the most common malignant tumor of the liver. Identifying specific molecular markers that can predict HCC prognosis is extremely important. The protein deoxythymidylate kinase (DTYMK) has been reported to contribute to unfavorable prognosis in non-small cell lung cancer patients, but its role in the prediction of HCC patient prognosis has not been clarified.

Methods

Samples from the TCGA and GEO databases were consecutively enrolled for gene expression analysis, clinicopathology analysis, immune microenvironment analysis and chemotherapeutic response prediction. The results were validated using 86 samples from the First Affiliated Hospital of Sun Yat-sen University. Cox regression analysis was used to analyze the effect of DTYMK on progression-free survival (PFS) and overall survival (OS). Functional enrichment analysis was used to describe the marker pathways that were significantly related to DTYMK. TIMER (Tumor Immune Estimation Resource), TISIDB (Tumor and Immune System Interaction DataBase) and CIBERSORT (Cell type Identification By Estimating Relative Subsets Of RNA Transcripts) were used to explore the immune microenvironment.

Results

We found that DTYMK expression upregulation is associated with poor prognosis in HCC patients and tightly related to the pathways regulating the cell cycle and acid metabolism. Our findings revealed that hepatocellular carcinoma cell lines with high DTYMK expression were more sensitive to sorafenib and many other chemotherapeutic drugs. We also found an inhibiting effect of DTYMK on the immune microenvironment in the process of tumorigenesis.

Discussion

We found that DTYMK has potential as a new prognostic and chemotherapeutic response biomarker for HCC patients and correlates with the immune microenvironment in HCC. However, there are some deficiencies in our study. First, this is a retrospective study that may lead to selection bias. Second, the protein expression of DTYMK was investigated via immunohistochemical analysis. Finally, we did not explore the exact underlying molecular mechanisms of DTYMK in tumorigenesis in this study, which is needed to be clarified in future research.

Six Metabolism Related mRNAs Predict the Prognosis of Patients With Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is one of the most common aggressive solid malignant tumors and current research regards HCC as a type of metabolic disease. This study aims to establish a metabolism-related mRNA signature model for risk assessment and prognosis prediction in HCC patients. Methods: HCC data were obtained from The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC) and Gene Enrichment Analysis (GSEA) website. Least absolute shrinkage and selection operator (LASSO) was used to screen out the candidate mRNAs and calculate the risk coefficient to establish the prognosis model. A high-risk group and low-risk group were separated for further study depending on their median risk score. The reliability of the prediction was evaluated in the validation cohort and the whole cohort. Results: A total of 548 differential mRNAs were identified from HCC samples (n = 374) and normal controls (n = 50), 45 of which were correlated with prognosis. A total of 373 samples met the screening criteria and there were randomly divided into the training cohort (n = 186) and the validation cohort (n = 187). In the training cohort, six metabolism-related mRNAs were used to construct a prognostic model with a LASSO regression model. Based on the risk model, the overall survival rate of the high-risk cohort was significantly lower than that of the low-risk cohort. The results of a time-ROC curve proved that the risk score (AUC = 0.849) had a higher prognostic value than the pathological grade, clinical stage, age or gender. Conclusion: The model constructed by the six metabolism-related mRNAs has a significant value for survival prediction and can be applied to guide the evaluation of HCC and the designation of clinical therapy.

Analysis of m6A RNA Methylation-Related Genes in Liver Hepatocellular Carcinoma and Their Correlation with Survival

N6-methyladenosine (m6A) modification on RNA plays an important role in tumorigenesis and metastasis, which could change gene expression and even function at multiple levels such as RNA splicing, stability, translocation, and translation. In this study, we aim to conduct a comprehensive analysis on m6A RNA methylation-related genes, including m6A RNA methylation regulators and m6A RNA methylation-modified genes, in liver hepatocellular carcinoma, and their relationship with survival and clinical features. Data, which consist of the expression of widely reported m6A RNA methylation-related genes in liver hepatocellular carcinoma from The Cancer Genome Atlas (TCGA), were analyzed by one-way ANOVA, Univariate Cox regression, a protein–protein interaction network, gene enrichment analysis, feature screening, a risk prognostic model, correlation analysis, and consensus clustering analysis. In total, 405 of the m6A RNA methylation-related genes were found based on one-way ANOVA. Among them, DNA topoisomerase 2-alpha (TOP2A), exodeoxyribonuclease 1 (EXO1), ser-ine/threonine-protein kinase Nek2 (NEK2), baculoviral IAP repeat-containing protein 5 (BIRC5), hyaluronan mediated motility receptor (HMMR), structural maintenance of chromosomes protein 4 (SMC4), bloom syndrome protein (BLM), ca-sein kinase I isoform epsilon (CSNK1E), cytoskeleton-associated protein 5 (CKAP5), and inner centromere protein (INCENP), which were m6A RNA methylation-modified genes, were recognized as the hub genes based on the protein–protein interaction analysis. The risk prognostic model showed that gender, AJCC stage, grade, T, and N were significantly different between the subgroup with the high and low risk groups. The AUC, the evaluation parameter of the prediction model which was built by RandomForest, was 0.7. Furthermore, two subgroups were divided by consensus clustering analysis, in which stage, grade, and T differed. We identified the important genes expressed significantly among two clusters, including uridine-cytidine kinase 2 (UCK2), filensin (BFSP1), tubulin-specific chaperone D (TBCD), histone-lysine N-methyltransferase PRDM16 (PRDM16), phosphorylase b ki-nase regulatory subunit alpha (PHKA2), serine/threonine-protein kinase BRSK2 (BRSK2), Arf-GAP with coiled-coil (ACAP3), general transcription factor 3C polypep-tide 2 (GTF3C2), and guanine nucleotide exchange factor MSS4 (RABIF). In our study, the m6A RNA methylation-related genes in liver hepatocellular carcinoma were analyzed systematically, including the expression, interaction, function, and prognostic values, which provided an important theoretical basis for m6A RNA methylation in liver cancer. The nine important m6A-related genes could be prognostic markers in the survival time of patients.

CMTM3 Overexpression Predicts Poor Survival and Promotes Proliferation and Migration in Pancreatic Cancer

Background: Recent evidence has shown that CKLF-like MARVEL transmembrane domain containing 3 (CMTM3) promoted carcinogenesis and tumor progression in a variety of cancer types. The goal of our study is to investigate the association between CMTM3 and pancreatic cancer (PC). Materials and Methods: In current study, data from public databases was used to analyze CMTM3 expression in PC. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) were used to investigate CMTM3 expression and determine its clinical significance in PC. Then CMTM3 promoting PC aggressiveness was demonstrated in vitro experiments by cell proliferation and migration assay. Functional and pathway enrichment analyses were performed to evaluate the potential role of CMTM3 in PC. Results: Results of qRT-PCR and IHC revealed that CMTM3 was significantly overexpressed in PC tissues. High CMTM3 expression was an independent risk factor for poor prognosis of PC patients. Overexpression of CMTM3 was associated with poor overall survival (P-value =0.031) and disease-free survival (P-value =0.0047) in the TCGA cohort. Functional and pathway enrichment analyses showed that CMTM3 were enriched in "Regulation of cell proliferation and regulation of cell differentiation, cell morphogenesis, regulation of cell differentiation, Hedgehog signaling pathway, Wnt signaling pathway, ECM-receptor interaction and pathways in cancer". In PC cell lines, CCK8, clone formation and transwell assays showed that CMTM3 knockdown inhibited cells proliferation and migration. Conclusion: CMTM3 was overexpressed and promotes tumor aggressiveness in PC. Our findings provided a novel therapeutic target for PC.

Development of a macrophages-related 4-gene signature and nomogram for the overall survival prediction of hepatocellular carcinoma based on WGCNA and LASSO algorithm

BACKGROUND

Immune system instability and poor prognosis are the two major clinical performance of hepatocellular carcinoma (HCC). Abnormal expression of MiR-424-5p has been reported to accelerate the progression of liver cancer, but it mediated immune cell infiltration imbalance is still unknown. We aim to mine the immune-related genes (IRGs) targeted by miR-424-5p and construct a multi-gene signature to improve the prognostic prediction of HCC.

METHODS

The HCC-related data of the cancer genome atlas (TCGA) database and the GSE14520 dataset of the gene expression omnibus (GEO) database were downloaded as the discovery dataset and the validation dataset, respectively. Weighted gene co-expression network analysis (WGCNA), the deconvolution algorithm of CIBERSORT and LASSO algorithm participated in the identification of IRGs and the development of prognostic signature and nomogram.

RESULTS

Our study found that the abundance of macrophages M0, M1 and M2 are all drastically changed during the cancerous process. A total of 920 macrophages infiltration-related LRGs were identified and a novel 4-gene signature (CDCA8, CBX2, UCK2 and SOCS2) with superior prognostic independence was established. The prognostic signature based risk score has superior capability to identify high-risk patients and predict overall survival (p < 0.001; AUC = 0.798 for 1 year; AUC = 0.748 for 3 years; AUC = 0.721 for 5 years). And it (C-index = 0.726) has a better prognostic potential than the TNM stage (C-index = 0.619), which is widely adopted in clinical practice. Additionally, the nomogram formed by combining the risk score and TNM stage further improved the accuracy of survival prediction (C-index = 0.733).

CONCLUSION

In summary, the immune landscape with abnormal infiltration of macrophages may be one of the prelude to the cancerous process. The novel macrophages-related 4-gene signature is expected to become a potential prognostic marker in liver cancer.

Overexpression of GIHCG is Associated with a Poor Prognosis and Immune Infiltration in Hepatocellular Carcinoma

Purpose

Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed digestive cancers and the fourth leading cause of death worldwide. Long noncoding RNAs (lncRNAs) with key roles in HCC development and progression have emerged and are used in the diagnosis and prognostic prediction of HCC. The lncRNA gradually increased during hepatocarcinogenesis (GIHCG) is a novel lncRNA with aberrant expression in many tumors, but its prognostic value and biological role in HCC have not been fully studied. Thus, the aim of this study was to explore the expression pattern and potential biological role of GIHCG in HCC.

Patients and Methods

The expression pattern of GIHCG in HCC was analyzed in our HCC cohort and validated in The Cancer Genome Atlas (TCGA) database. To assess the prognostic value of GIHCG, survival analyses and Cox regression analyses were carried out in two HCC cohorts. Functional enrichment analysis was used to predict the gene sets and pathways related to aberrant GIHCG expression. Furthermore, the relationship between GIHCG expression and immune infiltration in HCC was analyzed.

Results

GIHCG was highly expressed in HCC tissues compared with normal liver tissues. In addition, high GIHCG expression was significantly correlated with inferior clinicopathological characteristics and shorter survival times. High GIHCG expression was an independent prognostic factor for overall survival and disease-free survival in the HCC cohort in our center and in the TCGA-LIHC cohort. Hallmark terms such as “G2M checkpoint”, “MYC targets” and “DNA repair” were enriched in the GIHCG high-expression groups. High GIHCG expression negatively correlated with the infiltration of memory CD4+ and CD8+ T cells, natural killer cells, macrophages, dendritic cells, neutrophils and monocytes.

Conclusion

The findings of our study indicate that GIHCG is a biomarker that can be used to predict the prognosis of HCC patients and is correlated with immune cell infiltration in HCC.

Prognostic roles of metabolic reprogramming-associated genes in patients with hepatocellular carcinoma

Metabolic reprogramming for adaptation to the tumor microenvironment is recognized as a hallmark of cancer. Although many altered metabolic genes have been reported to be associated with tumor pathological processes, systematic analysis of metabolic genes implicated in hepatocellular carcinoma prognosis remains rare. The aim of this study was to identify key metabolic genes related to hepatocellular carcinoma, and to explore their clinical significance. We downloaded mRNA expression profiles and clinical hepatocellular carcinoma data from The Cancer Genome Atlas database to explore the prognostic roles of metabolic genes. Five prognosis-associated metabolic genes, including POLA1, UCK2, ACYP1, ENTPD2, and TXNRD1, were screened via univariate Cox regression analysis and a LASSO Cox regression model, which divided patients into high- and low-risk groups. Furthermore, gene set enrichment analysis revealed that significantly-enriched gene ontology terms and pathways involving high-risk patients were focused on regulation of nucleic and fatty acid metabolism. Taken together, our study identified five metabolic genes related to survival, which can be used to predict the prognosis of patients with hepatocellular carcinoma. These genes may play essential roles in metabolic microenvironment regulation, and represent potentially important candidate targets in metabolic therapy.

Identification of a prognostic signature of nine metabolism-related genes for hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the fifth most common cancer. Since changes in liver metabolism contribute to liver disease development, it is necessary to build a metabolism-related prognostic model for HCC.

Methods

We constructed a metabolism-related-gene (MRG) signature comprising nine genes, which segregated HCC patients into high- and low-risk groups.

Results

The survival rate (overall survival: OS; relapse-free survival; and progression-free survival) of patients in the low-risk group of The Cancer Genome Atlas (TCGA) cohort was significantly higher than that of patients in the high-risk group. The OS prognostic signature was validated in the International Cancer Genome Consortium independent cohort. The corresponding receiver operating characteristic curves of the model indicated that the signature had good diagnostic efficiency, in terms of improving OS over 1, 3, and 5 years. Hierarchical analysis demonstrated that the MRG signature was significantly associated with better prognosis in male patients, patients aged ≤ 65 years, and patients carrying the wild-type TP53 or CTNNB1 genes. A nomogram was established, and good performance and clinical practicability were confirmed. Additionally, using the GSE109211 dataset from the Gene Expression Omnibus database, we were able to verify that the nine genes in this MRG signature had different responses to sorafenib, suggesting that some of these MRGs may act as therapeutic targets for HCC.

Conclusions

We believe that these findings will add value in terms of the diagnosis, treatment, and prognosis of HCC.

Hypoxia-Induced lncRNA-NEAT1 Sustains the Growth of Hepatocellular Carcinoma via Regulation of miR-199a-3p/UCK2

Objective: The long noncoding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) has emerged as a novel player in hepatocellular carcinoma (HCC). Hypoxia is a common characteristic of the microenvironment of HCC. This study aimed to investigate whether lncRNA-NEAT1 is induced by hypoxia in HCC, and the mechanism that underlies LncRNA-NEAT1 function.

Methods: The expression changes of lncRNA-NEAT1 in HCC cell lines under hypoxic conditions were examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The regulatory effect of HIF-1α on lncRNA-NEAT1 was confirmed with chromatin immunoprecipitation (ChIP) and luciferase reporter assays. The function of lncRNA-NEAT1 on HCC cell growth under hypoxic conditions was determined by CCK-8 assay and flow cytometry. lncRNA -NEAT1 was predicted to serve as a competing endogenous RNA (ceRNA) within microRNA (miRNA)/mRNA axes based on microarray data, public HCC-related datasets and integrative bioinformatics analysis, and the miR-199a-3p/UCK2 axis was selected and validated by qRT-PCR, western blotting, RNA immunoprecipitation, and luciferase reporter analyses. The role of miR-199a-3p/UCK2 in HCC and its functional association with lncRNA-NEAT1 were assessed both in vitro and in vivo.

Results: LncRNA-NEAT1 expression was significantly induced by hypoxia in SNU-182 and HUH7 cells. HIF-1α was shown to regulate lncRNA-NEAT1 transcription. Under hypoxic conditions, lncRNA-NEAT1 maintained the growth of HCC cells and inhibited apoptosis and cell cycle arrest. LncRNA-NEAT1 was predicted to regulate a panel of HCC-associated miRNA-mRNA pairs consisting of 8 miRNAs and 13 mRNAs. LncRNA-NEAT1 was shown to function as a ceRNA of miR-199a-3p/UCK2 both in HCC cells under hypoxic conditions and in an animal model.

Conclusion: LncRNA-NEAT1 is a hypoxia-responsive lncRNA in HCC cell lines Insilico evidence suggested that LncRNA-NEAT1 may sustainthe growth of HCC cells by regulating HCC-associated mRNAs that interact with tumor-suppressive miRNAs. The lncRNA-NEAT1/miR-199a-3p/UCK2 pathway may contribute to the progression of HCC cell lines in a hypoxic microenvironment and therefore may represent a novel therapeutic target for HCC.

Comprehensive analysis reveals a metabolic ten-gene signature in hepatocellular carcinoma

Background

Due to the complicated molecular and cellular heterogeneity in hepatocellular carcinoma (HCC), the morbidity and mortality still remains high level in the world. However, the number of novel metabolic biomarkers and prognostic models could be applied to predict the survival of HCC patients is still small. In this study, we constructed a metabolic gene signature by systematically analyzing the data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and International Cancer Genome Consortium (ICGC).

Methods

Differentially expressed genes (DEGs) between tumors and paired non-tumor samples of 50 patients from TCGA dataset were calculated for subsequent analysis. Univariate cox proportional hazard regression and LASSO analysis were performed to construct a gene signature. The Kaplan–Meier analysis, time-dependent receiver operating characteristic (ROC), Univariate and Multivariate Cox regression analysis, stratification analysis were used to assess the prognostic value of the gene signature. Furthermore, the reliability and validity were validated in four types of testing cohorts. Moreover, the diagnostic capability of the gene signature was investigated to further explore the clinical significance. Finally, Go enrichment analysis and Gene Set Enrichment Analysis (GSEA) have been performed to reveal the different biological processes and signaling pathways which were active in high risk or low risk group.

Results

Ten prognostic genes were identified and a gene signature were constructed to predict overall survival (OS). The gene signature has demonstrated an excellent ability for predicting survival prognosis. Univariate and Multivariate analysis revealed the gene signature was an independent prognostic factor. Furthermore, stratification analysis indicated the model was a clinically and statistically significant for all subgroups. Moreover, the gene signature demonstrated a high diagnostic capability in differentiating normal tissue and HCC. Finally, several significant biological processes and pathways have been identified to provide new insights into the development of HCC.

Conclusion

The study have identified ten metabolic prognostic genes and developed a prognostic gene signature to provide more powerful prognostic information and improve the survival prediction for HCC.

Obg-like ATPase 1 (OLA1) overexpression predicts poor prognosis and promotes tumor progression by regulating P21/CDK2 in hepatocellular carcinoma

Background: Obg-like ATPase 1 (OLA1) has been found to have a dual role in cancers. However, the relationship between OLA1 and hepatocellular carcinoma (HCC) remains unclear.

Results: High expression of OLA1 in HCC was detected in public datasets and clinical samples, and correlated with poor prognosis. Downregulation of OLA1 significantly inhibited the proliferation, migration, invasion and tumorigenicity of HCC cells. Mechanistically, GSEA showed that OLA1 might promote tumor progression by regulating the cell cycle and apoptosis. In addition, OLA1 knockdown resulted in G0/G1 phase arrest and high levels of apoptosis. OLA1 could bind with P21 and upregulate CDK2 expression to promote HCC progression.

Conclusions: Overall, these findings uncover a role for OLA1 in regulating the proliferation and apoptosis of HCC cells.

Materials and methods: The Cancer Genome Atlas and Gene Expression Omnibus datasets were analyzed to identify gene expression. Immunohistochemistry staining, western blot and real-time polymerase chain reaction were performed to evaluate OLA1 expression in samples. Cell count Kit-8, wound-healing, transwell and flow cytometry assays were used to analyze HCC cell progression. Subcutaneous xenotransplantation models were used to investigate the role of OLA1 in vivo. Coimmunoprecipitation was used to analyze protein interactions.

Uridine-cytidine kinase 2 (UCK2): A potential diagnostic and prognostic biomarker for lung cancer

Lung cancer has the highest morbidity and mortality among all cancers. Discovery of early diagnostic and prognostic biomarkers of lung cancer can greatly facilitate the survival rate and reduce its mortality. In our study, by analyzing Gene Expression Omnibus and Oncomine databases, we found a novel potential oncogene uridine-cytidine kinase 2 (UCK2), which was overexpressed in lung tumor tissues compared to adjacent nontumor tissues or normal lung. Then we confirmed this finding in clinical samples. Specifically, UCK2 was identified as highly expressed in stage IA lung cancer with a high diagnostic accuracy (area under the receiver operating characteristic curve > 0.9). We also found that high UCK2 expression was related to poorer clinicopathological features, such as higher T stage and N stage and higher probability of early recurrence. Furthermore, we found that patients with high UCK2 expression had poorer first progression survival and overall survival than patients with low UCK2 expression. Univariate and multivariate Cox regression analyses showed that UCK2 was an independent risk factor related with worse DFS and OS. By gene set enrichment analysis, tumor-associated biological processes and signaling pathways were enriched in the UCK2 overexpression group, which indicated that UCK2 might play a vital role in lung cancer. Furthermore, in cytology experiments, we found that knockdown of UCK2 could suppress the proliferation and migration of lung cancer cells. In conclusion, our study indicated that UCK2 might be a potential early diagnostic and prognostic biomarker for lung cancer.

Identification of a four-gene metabolic signature predicting overall survival for hepatocellular carcinoma

While hundreds of consistently altered metabolic genes had been identified in hepatocellular carcinoma (HCC), the prognostic role of them remains to be further elucidated. Messenger RNA expression profiles and clinicopathological data were downloaded from The Cancer Genome Atlas-Liver Hepatocellular Carcinoma and GSE14520 data set from the Gene Expression Omnibus database. Univariate Cox regression analysis and lasso Cox regression model established a novel four-gene metabolic signature (including acetyl-CoA acetyltransferase 1, glutamic-oxaloacetic transaminase 2, phosphatidylserine synthase 2, and uridine-cytidine kinase 2) for HCC prognosis prediction. Patients in the high-risk group shown significantly poorer survival than patients in the low-risk group. The signature was significantly correlated with other negative prognostic factors such as higher α-fetoprotein. The signature was found to be an independent prognostic factor for HCC survival. Nomogram including the signature shown some clinical net benefit for overall survival prediction. Furthermore, gene set enrichment analyses revealed several significantly enriched pathways, which might help explain the underlying mechanisms. Our study identified a novel robust four-gene metabolic signature for HCC prognosis prediction. The signature might reflect the dysregulated metabolic microenvironment and provided potential biomarkers for metabolic therapy and treatment response prediction in HCC.